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2024-01-01 | The steady-state and dynamic design of experiments for 53° sweep lambda wing-unmanned combat aerial vehicles (UCAV) configuration is discussed in detail. The design of the experiments was done in the Universiti Teknologi Malaysia Low-Speed wind Tunnel (UTM-LST) and contains force and moments balance and surface flow visualization with the pitch angle and yaw angle variation for the steady-state experiments and the dynamic oscillatory rig facility with 1 degree of freedom oscillating mechanism was fixed to rotate in yawing axis to focus on the sensitivity for the yaw angle for the dynamic investigations. The steady-state experiments will be capable to give the steady-state aerodynamic derivatives, while the dynamic testing will provide the trainset aerodynamic derivatives. The steady-state and the dynamic measurements will help in studying the unsteadiness and the uncertainties of the flow over the wing configuration. | Design of Experiments for Wind Tunnel Testing of 53° Sweep Lambda UCAV Configuration | 10.1007/978-3-031-38446-2_52 |
2024-01-01 | This paper compares three ML-pipelines in Air Quality (AQ) Systems, namely a fog layer management model for IoT-systems, a low-cost AQ sensor system with sensor calibration and data fusion competences and a ML-method research based on low-cost OpenSensorMap. The three ML-pipelines are described, commonalities and differences worked out and the advantages of every technique are led over in an effort of a combined ML-pipeline which could be realised in a scientific cooperation of the three groups. | Commonalities and Differences in ML-Pipelines for Air Quality Systems | 10.1007/978-3-031-46902-2_2 |
2024-01-01 | Introduction Traumatic brain injury (TBI) Traumatic Brain Injury (TBI) is one of the main reasons for disability and death in patients. There is evidence showing exogenous nerve growth factor (NGF) Nerve Growth Factor (NGF) can promote neuron axonal outgrowth and prevent injured neurons from dying. However, as a highly selective barrier, the blood–brain barrier (BBB) Blood-Brain Barrier (BBB) hampers most of the therapeutic drugs, including NGF, from entering the central nervous system (CNS) Central Nervous System (CNS) for TBI treatments. Some approaches bypassing the BBB, such as intracerebroventricular and intraparenchymal infusion, can help exogenous NGF Nerve Growth Factor (NGF) to enter the brain, but such invasive routes may cause hemorrhage and infection in the brain. Since poly(butyl cyanoacrylate) (PBCA) nanoparticles can cross the BBB in vivo, these particles are suggested as a drug delivery Drug delivery vector to the CNS. In this chapter, the author reviews TBI treatments and challenges, BBB features, and how PBCA nanoparticles PBCA nanoparticles deliver therapeutic drugs such as NGF to cross the BBB for the treatments of CNS diseases including TBI. Methods To write this review, the author searched the biomedical literature database on PubMed of the National Library of Medicine and the scholarly literature via Google Scholar. The keywords the author used included TBI, NGF Nerve Growth Factor (NGF) , BBB, drug delivery Drug delivery , PBCA nanoparticles PBCA nanoparticles , nanomedicine, and nanotoxicity. Results The intravenous NGF Nerve Growth Factor (NGF) delivery to treat CNS diseases including TBI is still limited by the BBB. PBCA nanoparticles PBCA nanoparticles can help intravenously injected NGF Nerve Growth Factor (NGF) to penetrate the BBB into the brain parenchyma, preserve its biological activity, and treat TBI and neurodegenerative disease efficiently. The mechanism underlying BBB crossing of PBCA nanoparticles PBCA nanoparticles is related to the transcytosis on the barrier mediated by apolipoprotein E (ApoE) Apolipoprotein E (ApoE) and low-density lipoprotein receptor (LDLR) Low-Density Lipoprotein Receptor (LDLR) . Also, PBCA nanoparticles PBCA nanoparticles are considered to be of low/no toxicity due to their biodegradation. Conclusions PBCA nanoparticles PBCA nanoparticles are efficient vectors for the delivery of NGF to the brain and treat TBI in animals. | Poly(Butyl Cyanoacrylate) Nanoparticles Deliver β-Nerve Growth Factor to the Brain After Traumatic Brain Injury | 10.1007/978-3-031-49744-5_6 |
2024-01-01 | Purpose To investigate the effect of low-intensity extracorporeal shock wave therapy (LiESWT) on lipopolysaccharide (LPS)-induced cystitis in an animal model of interstitial cystitis/bladder pain syndrome (IC/BPS). Methods Sprague–Dawley rats were divided into three groups: control, cystitis (LPS group, intravesical injection of LPS (1 mg) twice), and cystitis with LiESWT (LiESWT group). On the third and fourth days, LiESWT was administered (0.12 mJ/mm 2 , 300 shots each time) on the lower abdomen toward the bladder. On the seventh day, the rats underwent pain assessment and a metabolic cage study. Subsequently, a continuous cystometrogram (CMG) was performed under urethane anaesthesia. Immunohistochemical studies were also performed, including S-100 staining, an immunohistochemical marker of Schwann cells in the bladder. Results In the LPS group, the pain threshold in the lower abdomen was significantly lower than that in the control group. In the metabolic cage study, the mean voided volume in the LPS group significantly increased. The CMG also revealed a significant decrease in bladder contraction amplitude, compatible with detrusor underactivity in the LPS group. Immunohistochemical studies showed inflammatory changes in the submucosa, increased fibrosis, and decreased S-100 stain-positive areas in the muscle layer of the LPS group. In the LiESWT group, tactile allodynia and bladder function were ameliorated, and S-100 stain-positive areas were increased. Conclusion By restoring nerve damage, LiESWT improved lower abdominal pain sensitivity and bladder function in an LPS-induced cystitis rat model. This study suggests that LiESWT may be a new therapeutic modality for IC/BPS. | Effects of low-intensity extracorporeal shock wave therapy on lipopolysaccharide cystitis in a rat model of interstitial cystitis/bladder pain syndrome | 10.1007/s11255-023-03770-3 |
2024-01-01 | Current residential air-condition and heat pump (ACHP) systems mainly use the high-pressure refrigerant R410A with scroll or rolling piston type compressors. With the continuous push on reducing the carbon emission, low-GWP refrigerants with lower pressure and density will be used in ACHP systems to replace R410A soon. Compressors must be resized to achieve similar efficiencies at the matched cooling capacity for low-pressure refrigerants. A physics-based model using geometries and refrigerant properties as input that can predict the compressor performance is desired to provide design guidance on compressor sizing. In this study, the open-source modeling platform (PDSim) based on the mechanistic chamber model is used to study the sizing requirement to match the desired capacity for scroll and rolling piston compressors at standard ANSI/AHRI 210/240 conditions. For each type of compressor, a detailed simulation model is created, validated, and tuned using the experimental data available to ensure accurate prediction on refrigerant mass flow rate, power, and efficiencies. The validated models are then used to run sensitivity study on compressor displacement for R410A, R134a and R1234ze(E), which are selected as representatives for different pressure levels. The needed displacement at different volumetric efficiencies and isentropic efficiencies is reported and compared. | Sizing of Scroll and Rolling Piston Compressor for Low-Pressure Refrigerants in Residential Air Conditioning and Heat Pump Systems | 10.1007/978-3-031-42663-6_64 |
2024-01-01 | Under the impact of “double-carbon” target, transition finance has an important impact on green innovation of Chinese double-high enterprises. Using a sample of 4270 high-polluting and high-energy-consumption listed enterprises (referred to as double-high enterprises) in China from 2012 to 2021, this paper empirically examines the impact of transition finance on the green innovation of China’s double-high enterprises by using a fixed-effects model. The study finds that transition finance can have a facilitating effect on green innovation in double-high enterprises. The intermediary mechanism test shows that transition finance can promote green innovation of double-high enterprises through alleviating financing constraints, increasing the level of green management, and enhancing the policy orientation effect. The heterogeneity test finds that transition finance promotes green innovation more significantly for the double-high enterprises that are state-owned, large-scale, and located in regions with high levels of intellectual property protection. Further research finds that the role of transition finance in promoting green innovation in double-high enterprises helps to promote the achievement of green development of double-high enterprises. | How does transition finance influence green innovation of high-polluting and high-energy-consuming enterprises? Evidence from China | 10.1007/s11356-023-31360-4 |
2024-01-01 | The chapter’s topic is related to the best tourist behavior practices for Sustainable Development in the Protected Natural Area of Cumbres de Majalca in a post-pandemic tourism context. The research problem is based on different sources of environmental impact like forest fires; uncontrolled grazing; use of off-road vehicles; the opening of unestablished roads that destroy vegetation, accelerated erosion, and generate dust pollution and harmful noise; as well as the over-tourism associated with vacation periods. This chapter aims to diagnose the current scenario and project management strategies for tourism with low environmental impact based on sustainability and responsible environmental behavior of visitors in Cumbres de Majalca National Park, Chihuahua. The study was based on qualitative, multidisciplinary, and transversal research principles; empirical methods such as observation, document analysis, diagnostic tests, and group work were used. The research of the visitor’s behavior and their relationships with the experiential landscape was based on a field visit to the destination with undergraduate tourism students from the Autonomous University of Ciudad Juárez. The main findings are the diagnosis of the current scenario characterized by high negative impacts and the projection of the desired scenario based on the development of strategies for tourism with low environmental impact according to the sustainability principles and the environmental visitor’s responsible behavior. This proposal allows the operationalization and instrumentation of the Park Management Program in a post-pandemic context. | Tourist Behavior for Sustainable Development in the Cumbres de Majalca National Park, Mexico: Challenges in a Post-pandemic Context | 10.1007/978-3-031-45866-8_7 |
2024-01-01 | In the quest to strengthen resilient and sustainable recovery in the post-COVID-19 era, there is a huge requirement for manufacturing firms to adopt green finance which is dominated by green bond issuance. Nevertheless, published studies that provide insights on factors that influence the issuance of green bonds within manufacturing firms in the post-COVID-19 era and the impact on sustainable outcomes are currently non-existent. Therefore, this study analyzed the interrelationships that exist between the influencing factors of green bond issuance within manufacturing firms using decision-making trial and evaluation laboratory (DEMATEL) and data from Nigerian manufacturing firms. Then, a structural model of their importance levels was illustrated using interpretive structural modeling (ISM) while their impact on manufacturing sustainability outcomes was estimated with the aid of evaluation based on distance from average solution (EDAS). The study results highlight the key influencing factors of green bond issuance as environmental competencies, policy framing, low corruption, public awareness, and government support thereby signifying the criticality of strong institutions in facilitating green finance in the post-pandemic era. Besides, the study results demonstrate that green finance can significantly strengthen manufacturing sustainability in the post-COVID-19 era via green bonds by enhancing sustainable waste management, technological growth, and quality improvement as well as reducing carbon emissions. The study findings can provide a reference to decision-makers in manufacturing enterprises to predict scenarios and enact policies that facilitate the success of green finance in the post-COVID-19 era to further develop a low-carbon economy and increase competitive edge. | Research on the interplay between green finance and manufacturing sustainability outcomes: insights for low-carbon economy in the post-COVID-19 era | 10.1007/s11356-023-31476-7 |
2024-01-01 | The popularization and widespread use of computed tomography (CT) in the field of medicine evocated public attention to the potential radiation exposure endured by patients. Reducing the radiation dose may lead to scattering noise and low resolution, which can adversely affect the radiologists’ judgment. Hence, this paper introduces a new network called PANet-UP-ESRGAN (PAUP-ESRGAN), specifically designed to obtain low-dose CT (LDCT) images with high peak signal-to-noise ratio (PSNR) and high resolution (HR). The model was trained on synthetic medical image data based on a Generative Adversarial Network (GAN). A degradation modeling process was introduced to accurately represent realistic degradation complexities. To reconstruct image edge textures, a pyramidal attention model call PANet was added before the middle of the multiple residual dense blocks (MRDB) in the generator to focus on high-frequency image information. The U-Net discriminator with spectral normalization was also designed to improve its efficiency and stabilize the training dynamics. The proposed PAUP-ESRGAN model was evaluated on the abdomen and lung image datasets, which demonstrated a significant improvement in terms of robustness of model and LDCT image detail reconstruction, compared to the latest real-esrgan network. Results showed that the mean PSNR increated by 19.1%, 25.05%, and 21.25%, the mean SSIM increated by 0.4%, 0.4%, and 0.4%, and the mean NRMSE decreated by 0.25%, 0.25%, and 0.35% at 2 $$\times$$ × , 4 $$\times$$ × , and 8 $$\times$$ × super-resolution scales, respectively. Experimental results demonstrate that our method outperforms the state-of-the-art super-resolution methods on restoring CT images with respect to peak signal-to-noise ratio (PSNR), structural similarity (SSIM) and normalized root-mean-square error (NRMSE) indices. | Super-Resolution Reconstruction of CT Images Based on Multi-scale Information Fused Generative Adversarial Networks | 10.1007/s10439-023-03412-w |
2024-01-01 | The present study aims to characterize the free stream flow of the newly installed recirculating water tunnel facility in the BIAHR Laboratory at the Indian Institute of Technology Kharagpur. This tunnel can operate at speeds ranging from 0.05 m/s to 0.40 m/s in the test section. The dimension of the test section is 400 × 400 × 1500 mm 3 in width, depth, and length respectively. An acoustic Doppler velocimetry is used to measure the instantaneous velocity in the test section at the frequency of 10 Hz with a measured accuracy of ± 1%. The flow velocity in the test section is found to vary linearly with motor speed, and the turbulence level decreases on increasing the motor speed. The average temporal stability in the tunnel is found to be less than 1%, and the maximum possible deviation in the spatial uniformity is less than ± 1.35%. Furthermore, the free stream turbulence intensity characteristics in the test section are determined at different operating velocities. | Characterization of the New Open Surface Recirculating Water Tunnel Facility at the Indian Institute of Technology Kharagpur | 10.1007/978-981-99-7047-6_18 |
2024-01-01 | A vital component of maintaining economic growth is the development of the power infrastructure. Most power plants in India are powered by traditional energy sources such as coal, diesel, oil, gas, hydropower, and nuclear power. Numerous techniques for solving the models and resolving the efficiency issue have been put out in recent years. To create a realistic mathematical system and use GEP in the model solutions, the goal of this work is to analyze the GEP for the candidate system by integrating all important system components. The planning of the test system is done for two separate planning horizons, which are 6 and 14 years, respectively. For the same power system, GEP mathematical modeling studies are conducted to examine the effects of the addition of a solar power plant with a storage facility. Based on (a) the investment strategies of introducing solar plants as an alternative candidate plant or as a replacement for existing High Emission Plants (HEP), (b) whether the Solar Plant with Storage (SPWS) or Without Storage (SPWNS) capacity, and (c) inclusion of treatment/penalty costs on emissions from HEP, this is planned in a four-level hierarchy. For anticipated solar penetration levels of 5–10 and 10–20% for 6 and 14 years of planning horizons, respectively, the sensitivity of the system performance elements such as the capacity added, total cost, and Expected Energy Not Served (EENS) is also carried. The system’s performance is very dependent on the FOR% that is expected. When SPWS is added to the system as an alternative investment candidate plant, the model studies present an upbeat prospect for power system planning. This study offers a four-level hierarchy to understand the full range of policy issues that may arise in GEP and enables planners to implement situation-specific solutions, while also attempting to illustrate the complexity of the decision-making process when introducing solar plants into an existing system. | Generation Expansion Planning Using Renewable Energy Sources with Storage | 10.1007/978-3-031-29586-7_3 |
2024-01-01 | Wide-range position shifters are very necessary components of ultra-low-voltage circuits and components. State-of-the-art position shifters will convert a sub threshold voltage to the standard voltage; their operating ranges will be limits to ranges, limiting the flexibility of dynamic voltage ranges. As a result, our paper proposed a new position shifter with an operating range of sub threshold voltage to standard force voltage and overhead and over position conversion. The edited Wilson current glass and general CMOS sense gates are used in the proposed position shifter, which is a cold-blooded structure. Using 65-nm technology, the simulation and dimension results were validated. According to the dimension results, the proposed position shifter’s minimum operating voltage was less than 200 mV. Using a 22-nm technology, the modeling and measurement results were confirmed. | Self-biased Cascade Current Mirror with Wide Range Level Shifter | 10.1007/978-3-031-34644-6_103 |
2024-01-01 | The oil production rate of the ultra-low permeability reservoir decreases rapidly after volume fracturing, and reservoir energy replenishment is in urgent need to enhance the production performance. However, due to the poor reservoir physical property, water injection into the ultra-low permeability reservoir is quite difficult, resulting in unsatisfactory development effect. To evaluate the effectiveness of water alternating CO 2 (CO 2 -WAG) flooding in ultra-low permeability reservoir block Z, oil samples from a typical well were used to carry out laboratory experiments, including oil composition analysis, constant composition expansion and CO 2 swelling test. After fitting the experimental results, a numerical simulation model containing four five-point patterns developed by CO 2 -WAG flooding was established. The production and seepage characteristics of CO 2 -WAG flooding were studied, and the parameter sensitivity analysis was conducted. The results showed that: (1) CO 2 -WAG flooding could maintain a longtime stable production with high oil rate, and significantly improve the production effect of the ultra-low permeability reservoir; besides, dynamic CO 2 storage could be achieved with the storage percent of 70% during the flooding process. (2) CO 2 -WAG flooding has the following effects, including replenishing reservoir energy, expanding sweeping volume and improving oil displacement efficiency, and the development effect is obviously better than that of water flooding. (3) When the CO 2 -WAG flooding was implemented immediately at the reservoir starting production with 6-month alternating cycle and 1:1 CO 2 -Water ratio, good production performance could be achieved. The results obtained from this research can provide guidance in effectively developing block Z. | Simulation Study on the Displacement Characteristics of an Ultra-Low Permeability Reservoir by CO2-WAG Flooding | 10.1007/978-3-031-42987-3_50 |
2024-01-01 | The dynamic derivative is a necessary parameter in the process of analyzing the stability of the aircraft and designing the control law. In view of the urgent need of the high-precision dynamic derivative wind tunnel test data for the development of large-scale military and civil aircraft and advanced layout aircraft in China, a new wind tunnel dynamic test system is developed driven by the coupling of electro-hydraulic motor and servo motor and whose oscillating mechanism is decoupled from the static angle-changing mechanism based on FL-51 wind tunnel of AVIC Aerodynamics Research Institute, which can conduct dynamic derivative test of pitch/yaw/roll oscillation modes with test model at the scale of 1–2.5 m under the wind speed range of 20–50 m/s. This test system uses electro-hydraulic motor to drive the oscillation mechanism and servo motor to drive the static angle-changing mechanism. We design the drive control scheme and introduce key technologies involved in the system design in detail. According to the Test index, we debug the motion index of the test system, and carry out the wind tunnel verification test with the standard dynamic model at the scale of 1 m and the wing-body fusion layout model at the scale of 2.4 m. The debugging results show that the test system has good static/dynamic control precision, and the performance index and function can achieve the design requirements. The wind tunnel test results indicate that the test system can obtain dynamic derivatives data with high accuracy and reasonable regularity, which can provide test platform support for the demand of dynamic derivative test data for the development of large wingspan military and civilian aircraft in China. | Design of Control System for Dynamic Derivative Test System in Low-Speed Wind Tunnel | 10.1007/978-981-99-8864-8_3 |
2024-01-01 | In this study, a three-level comparator architecture has been suggested to increase speed and decrease kickback noise. The additional amplified stage in the multiple comparators boosts voltage gain and speed in comparison to the traditional two-stage comparator. Furthermore, speed is increased by using nMOS input sets in both the regenerating and amplifies stages rather than just the regenerative stage as in the conventional two-stage arrangement. The three-stage comparator's kickback noise is greatly decreased by adding a pair of CMOS inputs at the amplification stage. This kickback noise is generated by NMOS kickback. Faster performance is achievable by introducing a second describing the steps while playback remains active. For better comparison, the suggested three-stage comparator and the standard two-stage comparator were both simulated by employing the identical 130-nm CMOS technology. According to the experimental findings, the redesigned comparator increases speed by 32% and decreases kickback noises by a factor of 10. | Low-Power High-Speed Modified Three-Stage Comparator with Low Kickback Noise | 10.1007/978-981-99-7077-3_31 |
2024-01-01 | The goal of the study was to check the hypothesis that low- and high-methane producers will react differently to the administration of non-digestible carbohydrates. It was discovered in our previous studies that Wistar rats from the Puschino nursery (SPF status) were low methane producers, whereas conventional rats from Stolbovaya nursery were high methane producers. Hydrogen and methane breath tests and the taxonomic content of the gut microbiota were evaluated in 25 rats from each nursery. Samples of the exhaled air were taken from awake rats using nose-only apparatus and analyzed by gas chromatography. The taxonomic content of the gut microbiota was evaluated in each rat by the 16S rRNA method. Lactulose, Guar Gum, and inulin were administered by gavage to each rat in 1-week time intervals. Levels of hydrogen and methane in the samples of exhaled air were measured during 8 h after carbohydrate administration. Taxonomic microbiome compositions were quite different between groups. Low methane-producing rats had low alpha and beta diversity, higher abundance of Christensenellaceae and Akkermansia bacteria, lower abundance of Helicobacteraceae, and absence of Methanobacteriaceae ) that show similarity to the microbiome of the newborns and children. High methane-producing rats (from Stobovaya nursery) had a much higher diversity of microbiota bacteria, a higher abundance of hydrogen-consuming microorganisms, like Helicobacteraceae and Methanobacteriaceae, and close to the microbiota composition in the elderly. The gavage of carbohydrates in low-methane-producing rats was followed just by the increase in hydrogen level in exhaled air, whereas the same carbohydrates evoked an increase in methane level only. We speculate that the administration of the exogenous hydrogen (hydrogen-rich water) will be more efficient in increasing the antioxidant defense in the elderly because taking the food fibers is not followed by the increase of hydrogen level in the blood. | Differential Effects of Carbohydrates on the Generation of Hydrogen and Methane in Low- and High-Methane-Producing Rats | 10.1007/978-3-031-47375-3_20 |
2024-01-01 | Watershed monitoring is critical for long-term water resource management, drought measures, and flood mitigation planning. Based on satellite data and a cloud-based platform, this study aimed to deploy a web-based application to monitor the sub-watersheds of the lower Palar River reach, which drain part of the Chengalpattu and Kanchipuram districts that are rapidly urbanizing. The geophysical parameters, terrain characteristics, meteorological parameters, and hydrological components of the watersheds were extracted from satellite data in this study. The satellite data was analyzed using the predefined algorithms through the advanced GIS tool Google Earth Engine (GEE). Much research is currently being conducted on revealing surface water potential and fluctuation monitoring using remotely sensed geospatial data and GIS tools. However, the traditional method involves collecting a large number of satellite-sensed images taken from the study area and then processing them in GIS software. The GEE is working on the cloud server, which is dedicated to the processing of satellite image data using machine learning code. GEE does not require image saving or collection, which are simple analyses of satellite data and mapping capabilities. The current study is intended to overcome technical limitations by providing a near real-time, cloud-based, and simple method for mapping hydrological components. Following that, a web-based application was created to provide access to geographical information to the government and other stakeholders. The dynamics of agricultural areas and townships and the state of the stream drainage system were identified without a site inspection. Post-flood information will be monitored, and it should direct the earliest and most beneficial relief operations. By selecting the flood event from the dropdown menu, users can obtain the extent of the flooded area. The web-based watershed monitoring application was deployed successfully. | Watershed Monitoring Application for Sub-watersheds of Lower Palar River Reach Using Remote Sensing Data and Google Earth Engine Platform | 10.1007/978-981-99-6229-7_10 |
2024-01-01 | Lower limb work-related musculoskeletal disorders have multifactorial etiology, primarily caused by prolonged exposure to physical risk factors, including awkward postures, repetitions, and forceful exertions. These disorders can significantly affect worker’s health and work performance. However, the literature regarding the risk factors of the lower limb work-related musculoskeletal disorders is generally under-represented. This study aims to identify the relative importance of the risk factors that lead to the development of each lower limb work-related musculoskeletal disorders. The research method was based on a questionnaire and interviews with ten health experts, namely: two orthopedists, two occupational doctors, four physiotherapists and two physiotherapists/osteopaths. The application of the questionnaire highlighted the difficulty in objectively characterizing the importance degree of the risk factors. Nevertheless, the interviews were quite relevant to complement the information regarding the most common risk factors contributing to the development of lower limb work-related musculoskeletal disorders. Overall, the expert's feedback indicates that workers exposed to prolonged standing work involving static postures are substantially more likely to develop lower limb work-related musculoskeletal disorders. The information gathered will be used in developing an assessment model to predict the possibility of developing lower limb work-related musculoskeletal disorders. | Risk Factors for Lower Limb Work-Related Musculoskeletal Disorders | 10.1007/978-3-031-38277-2_16 |
2023-12-30 | Epsilon-negative metamaterials (ENMs) have gained significant attention due to their promising applications in various fields, such as microwave absorption or shielding, radio transmission, and solar energy harvesting. However, for metal-based ENMs, negative permittivity is usually huge accompanied by high frequency dispersion behavior, which is difficult to achieve impedance matching and performance improvement. In this work, Co nanoparticles (NPs) encapsulated into positive-hexagon-shaped carbon nanosheets that were covered by carbon nanotubes (Co@PHCNTs) were synthesized by carbonizing the zeolitic imidazolate frameworks (ZIF), and negative permittivity with weak value and low-frequency dispersion simultaneously was achieved for the first time in metal-based ENMs by fabricating polyurethane/Co@PHCNT metamaterials. The carbon nanosheets with two-dimensional structure were beneficial to form interconnected networks in the metamaterials, and carbon nanosheets were able to reduce electron concentration of Co NPs, resulting in weakly negative permittivity value. Besides, the generation of CNTs on surfaces from carbon nanosheets greatly facilitated electron transport and improved electron mobility, leading to low-frequency dispersion behavior. Graphical Abstract | Weakly negative permittivity: metal–organic frameworks derived cobalt nanoparticles encapsulated by positive-hexagon-shaped carbon nanosheets | 10.1007/s42114-023-00800-7 |
2023-12-29 | The mechanisms controlling the dependence on low-velocity flow of the piloted ignition of a solid material under external radiant heating is investigated through a numerical modeling. The poly (methyl methacrylate) (PMMA) was used as the fuel. The objective of the present study is to gain insight into the intrinsic ignition mechanisms of a solid fuel, as well as to gain a more comprehensive understanding of the dynamical characteristics of the ignition process near the extinction limit. For this purpose, a two-dimensional numerical model has been developed using the Fire Dynamic Simulator (FDS5) code, in which both solid-phase and gas-phase reactions are calculated. Two radiant heat flux, which are 16 and 25 kW/m 2 were studied, and an external air flow was varied from 3 to 40 cm/s. The simulation results showed that transient gas reaction flashed before a continuous flame was attached to the sample surface for gas flow velocities lower than a critical value. As the flow velocity is reduced, the flashing time, which is defined as the time when any flame is seen above the sample surface, decreases, while the duration of flashing increases. The solid surface temperature and mass flow rate increase rapidly during flashing. The ignition time, which is defined as the time when a continuous flame is attached to the fuel surface, decreases, reaches a minimum, and then increases until ignition cannot occur. Mechanisms were considered to explain the ‘‘V-shaped” dependence of ignition time on flow-velocity, and two regimes were identified each having a different controlling mechanism: the mass transport regime where the ignition delay is controlled by the mixing of oxygen and pyrolyzate; and the heat transfer regime where the ignition delay is controlled by changes in convection heat losses and critical mass flux for ignition. With the decrease of the airflow velocity, the critical mass flux shows a trend of decreasing and then increasing, which is dominated by the mixing of the pyrolyzate and the oxidizer, while the critical temperature monotonically decreases, which is dominated by a reduction of the net heat flux at the fuel surface. The results provide further insight into the ignition behavior of solid fuel under low-velocity flow environment, and guidance about fire safety in microgravity environments. | Numerical Study on Pilot Ignition of a Thermally-Thick Solid Fuel with Low-Velocity Airflow in Microgravity | 10.1007/s12217-023-10092-7 |
2023-12-29 | The exploration of bifunctional electrocatalysts with high catalytic activity and long-term durability for low-temperature Zn-air batteries (ZABs) is an ongoing challenge. Here, quintet-shelled hollow spheres, P-doped multi-layer Co 3 O 4 (PM-Co 3 O 4 ), with enriched oxygen vacancies are prepared by thermally induced mass relocation and a simple phosphating process. Various advanced characterizations reveal P anion-induced effects on internal electronic structure and local coordination environment. The finite element method elucidates that the complex multi-layer spherical nanostructure is conducive to the transport and diffusion of OH − and O 2 . Benefiting from its unique structural features and abundant oxygen vacancies, the well-designed PM-Co 3 O 4 presents small reversible oxygen overpotential for catalyzing oxygen reduction/evolution reactions. Accordingly, the fabricated low-temperature ZABs based on PM-Co 3 O 4 as air-cathode exhibit high power density (20.8 mW·cm −2 ) and long-term stability (over 600 cycles) at the ultra-low temperature of −40 °C, outperforming state-of-art Pt/C+IrO 2 -based ZABs. Furthermore, the dynamic evolution mechanism of cobalt oxide catalysts during ZAB operation is elucidated. This work provides a guideline to design efficient electrocatalysts with regulated electronic configurations and exquisite nano-/microstructures for ZABs under extreme working conditions. | Structure and defect dual-engineering of cobalt oxides for low-temperature Zn-air batteries | 10.1007/s12274-023-6331-5 |
2023-12-29 | In this paper, waterborne polyurethane (WPU-SL) with high solid content and low viscosity was successfully prepared by compounding large particle size emulsion (WPU-L) with a variety of small particle size emulsions (WPU-S) by investigating the effects of small particle size type, particle size ratio, and volume ratio on the emulsion properties. A series of characterization techniques of the waterborne polyurethane was carried out by FTIR, DSC, contact angle, viscometer, particle size meter, and universal testing machine. The results show that the WPU-L/WPU-S = 5/1 emulsion has a high solid content, good emulsion stability, and excellent coating film properties. When WPU-S 1 and WPU-S 3 , two small particle size emulsions with a particle size ratio of 2.45 and 3.79, were emulsified with WPU-L, the solid content was up to 61.23%, the viscosity was only 342 mPa s, the tensile strength reached 20.97 MPa, and the adhesion grade was 5B, which was the most excellent overall performance, showing satisfactory results. Graphical Abstract | Preparation of high-solid, low-viscosity waterborne polyurethane: based on multiparticle size composite emulsification | 10.1007/s11998-023-00859-3 |
2023-12-29 | Despite the significant role that the Lower Don plays in Russia’s fishing industry, the region’s fisheries remain in a depressed state. It is well understood that the Tsimlyansk reservoir impacts the region’s fisheries, but the potential influence of climate change and associated reductions in snowmelt water flow remains under debate. The present study provides the first investigation of the effects of reservoir management and reduction in snowmelt water flow due to global warming on fish spawning independently. Using estimates of water discharge in the lower reaches of the Don, in the absence of the Tsimlyansk reservoir, the results showed that climate-related factors, although still significant, had a smaller effect on water discharge, compared with reservoir management regimes. Hydrological characteristics affecting fish reproduction (i.e., water discharge, water level, area and duration of floodplain inundation, and fingerling abundance) are decreasing under the reservoir influence by a factor of 1.5–3.2, while the declines associated with climate change are a factor of 1.4–2.1. Artificial fish reproduction and improvements in management of the Tsimlyansk reservoir could lead to restoration of fish stocks in the Lower Don. | Hydrological conditions of phytophilic fish reproduction in the Lower Don River under the influence of climate change and flow regulation | 10.1007/s10750-023-05432-y |
2023-12-29 | With more infrastructures being built in high-altitude regions, the impact of low atmospheric pressure on the stability of air bubbles in cementitious materials has aroused extensive attention. However, its influence is still inconclusive since it is difficult to isolate the factor of air pressure and study it. To solve this problem, the study investigated the bubble dynamic evolution in cement paste at standard atmospheric pressure (P = 0.1 MPa) and low atmospheric pressure (LAP = 0.8P, 0.6P, 0.4P, 0.2P) and revealed the mechanism of bubble instability under low atmospheric pressure. We established the bubble dynamic evolution equation in cement paste, computed the real-time bubble radius, resultant force, and critical time at different air pressure by MATLAB software. Results show that the maximum resultant force decreases by 50.0–57.7% when air pressure drops from P to 0.2P; both critical time ( $$t$$ t ) and radius increment ( $$\Delta R$$ Δ R ) increase with the reduction of air pressure and the increase of initial radius. It indicates that when at 0.2P, the resultant force which inhibits bubble expansion is reduced, the time required to prevent bubble expansion increases by 94–137%, and $$\Delta R$$ Δ R grows 122–140% larger than that at P, and the bubble is more prone to instability and rupture than that at P. The key to improving bubble stability in low atmospheric pressure is to reduce the initial radius of bubbles and increase the strength of the bubble film. This work firstly discovered the impact of low atmospheric pressure on bubble dynamic evolution in cement paste and proposed a new perspective to explore bubble stability at low atmospheric pressure. Graphical abstract | Investigation on the impact of low atmospheric pressure on bubble stability in cement-based materials | 10.1007/s43452-023-00824-2 |
2023-12-28 | Background The response of superheated emulsion detector with different halocarbons as active liquid to poly-energetic and mono-energetic neutrons has been carried out by different workers. The C 2 H 2 F 4 detectors have not been explored much. This liquid has shown the potentiality of sensitivity to low-mass dark matter. The previous calibration of this liquid was carried out with the poly-energetic neutrons. Purpose In the present work, to better characterize the detector with neutrons, it is irradiated with quasi-mono-energetic neutrons and the results are compared with neutrons from 241 Am-Be. To run the detector for the dark matter search, it is required to calibrate it with neutrons, preferably with mono-energetic neutrons. But mono-energetic neutron is not available at all establishments; hence, it was calibrated with quasi-mono-energetic neutrons. Method The response of superheated emulsion consisting of the droplets of C 2 H 2 F 4 has been studied using the quasi-mono-energetic neutrons. The superheated droplets have been fabricated in a visco-elastic gel matrix. The shock waves generated by the passage of the energetic particles are detected by the acoustic sensors coupled to the emulsion. The measurement has also been carried out for the blank target and beam-off conditions. Results and conclusion It is observed that the ( P var ) response of the emulsion in the low-frequency range is sharper for the quasi-mono-energetic neutrons from 7 Li ( p , n ) reaction and wider for the poly-energetic neutrons from 241 Am-Be. The fundamental frequency associated with bubble nucleation (FF values) is similar for the neutrons from 7 Li-target and 241 Am-Be source. The precise characterization of such detector is required for the application in neutron measurement as well as for the dark matter search experiment apart from the basic understanding of the radiation-induced bubble nucleation. | Response of C2H2F4 superheated emulsion to quasi-mono-energetic neutrons at low frequency | 10.1007/s41605-023-00433-w |
2023-12-26 | The experimental and numerical investigations on the dynamic responses and failure mechanisms of honeycomb panels under low-velocity impact were carried out in the present work. The carbon fiber composite hexagonal honeycomb panels were fabricated using the hot press molding method. Then, low-velocity drop-weight impact tests on the composite honeycomb panels were conducted under impact energy levels of 5J, 10J, 30J, 50J, 60J, 70J, and 100J to study the deformation mechanisms and damage modes. The VUMAT was developed to model the behavior of sandwich panels, in which a progressive damage model based on the strain-based failure criterion of composite fabric and Yeh delamination failure criteria was implemented in ABAQUS/Explicit. Two-dimensional topological honeycomb configurations with the same relative density were established. The energy absorption and load-bearing capacity of hexagonal, square, triangular, Kagome, and two kinds of circular (CS and CH types) honeycombs under 100J impact energy were discussed. The results showed that the circular honeycomb (CH type) had the largest first peak force of 6.714 kN, while the hexagonal honeycomb had the smallest first peak force of 3.715 kN. Compared with hexagonal honeycomb, the energy absorption of the triangle, Kagome, and circular honeycombs (CH type) were increased by 37.15%, 38.18%, and 47.06%, respectively. This study provided a series of experimental and numerical results, which could provide a reference for selecting suitable honeycomb configurations in the protection field. | Experimental and Numerical Study of Composite Honeycomb Sandwich Structures Under Low-Velocity Impact | 10.1007/s10443-023-10190-0 |
2023-12-24 | The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control process. The investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the steel. The results revealed that the increase in Ni content from 1 to 2 wt.% reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed, which promoted grain refinement. The optimized combination of grain size, high-angle grain boundaries (HAGBs), and martensite-austenite (M–A) islands parameter contributed to the excellent impact toughness of S1 steel at –100 °C (impact absorbed energy of 218.2 J at –100 °C). As the Mo increases from 0 to 2 wt.%, the matrix structure changes from multiphase structure to granular bainite, which increases the average effective grain size to ~ 4.62 μm and reduces HAGBs proportion to ~ 36.22%. With these changes, the low-temperature impact toughness of S3 steel is weakened. In addition, based on the analysis of the characteristics of crack propagation path, it was found that M–A islands with low content (~ 2.21%) and small size (~ 1.76 μm) significantly retarded crack propagation, and the fracture model of M–A islands with different morphologies was further proposed. Furthermore, correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters. | Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel | 10.1007/s42243-023-01126-w |
2023-12-23 | Objectives Low-frequency, low-intensity ultrasound is commonly utilized in various dental research fields to remove biofilms from surfaces, but no clear recommendation exists in dental studies so far. Therefore, this study aims to optimize the sonication procedure for the dental field to efficiently detach bacteria while preserving viability. Materials and methods Initial biofilm was formed in vivo on bovine enamel slabs ( n = 6) which were worn by four healthy participants for 4 h and 24 h. The enamel slabs covered with biofilm were then ultrasonicated ex vivo for various time periods (0, 1, 2, 4, 6 min). Colony-forming units were determined for quantification, and bacteria were identified using MALDI-TOF. Scanning electron microscopic images were taken to also examine the efficiency of ultrasonications for different time periods. Results Ultrasonication for 1 min resulted in the highest bacterial counts, with at least 4.5-fold number compared to the non-sonicated control ( p < 0.05). Most bacteria were detached within the first 2 min of sonication, but there were still bacteria detached afterwards, although significantly fewer ( p < 0.0001). The highest bacterial diversity was observed after 1 and 2 min of sonication ( p < 0.03). Longer sonication periods negatively affected bacterial counts of anaerobes, Gram-negative bacteria, and bacilli. Scanning electron microscopic images demonstrated the ability of ultrasound to desorb microorganisms, as well as revealing cell damage and remaining bacteria. Conclusions With the use of low-frequency, low-intensity ultrasound, significantly higher bacterial counts and diversity can be reached. A shorter sonication time of 1 min shows the best results overall. Clinical relevance This standardization is recommended to study initial oral biofilms aged up to 24 h to maximize the outcome of experiments and lead to better comparability of studies. | Optimizing the use of low-frequency ultrasound for bacterial detachment of in vivo biofilms in dental research—a methodological study | 10.1007/s00784-023-05397-1 |
2023-12-23 | Objective Lumbar facet joint (LFJ) syndrome is one of the common causes of low back pain (LBP). There are different views on percutaneous and endoscopic radiofrequency. The purpose of this systematic review and meta-analysis is to explore the therapeutic effect of radiofrequency ablation on LBP originating from LFJ and compare the therapeutic effect of percutaneous radiofrequency ablation and endoscopic neurotomy. Methods We included randomized controlled trials which compared the efficiency of percutaneous radiofrequency ablation and conservative treatment (sham procedures, facet joint injection, physiotherapy, exercise, or oral medication) or compared the efficiency of percutaneous radiofrequency ablation and endoscopic neurotomy for LFJ syndrome. We searched in PubMed and Web of Science from inception to March 27, 2023. Meta-analysis was performed using RevMan 5.4 software. Results A total of 11 randomized controlled trials were included. Among them, nine studies were used for evaluating efficiency of percutaneous radiofrequency ablation, and two studies were used for evaluating efficiency of endoscopic neurotomy. Pooled data from two studies reporting outcomes at 1 year did not show a benefit from facet joint denervation by comparing the percutaneous radiofrequency ablation and conservative treatment (standardized mean difference (SMD) = −0.87, 95% confidence interval (CI) [−2.10, 0.37], P = 0.17). There was no significant difference between percutaneous radiofrequency ablation and endoscopic neurotomy at 1-month follow-up (mean difference (MD) = −0.13, 95%CI [−0.18, −0.44], P = 0.41). At 12-month follow-up the pain relief in the endoscopic neurotomy was significantly better than that in the percutaneous radiofrequency ablation group (MD = 1.98, 95%CI [1.60, 2.36], P < 0 .0001). Conclusion The LBP was significantly relieved shortly after percutaneous radiofrequency ablation. Compared with percutaneous radiofrequency ablation, endoscopic neurotomy seems to have a longer effect. A longer follow-up period is needed to confirm its effectiveness. | Percutaneous radiofrequency ablation and endoscopic neurotomy for lumbar facet joint syndrome: are they good enough? | 10.1007/s00586-023-08078-5 |
2023-12-22 | Low permeability sandstones are widely found in oil and gas reservoirs. To gain a better understanding of the mechanical behavior of low-permeability sandstones, the permeability evolution of sandstone is investigated experimentally under triaxial compression loading, especially with multiple loading/unloading cycles, using two groups of experimental tests. The one is the triaxial compression tests with and without loading/unloading cycles. The other one is gas permeability tests in triaxial compression. The test results show that the stress–strain curves exhibited obvious nonlinear behavior and softening characteristics. It was demonstrated that important strain hysteresis occurred during the loading and unloading test. The permeability evolution of sandstone exhibited three phases: slow decrease, slow increase and rapid increase. Meanwhile, the permeability evolution followed the evolution of damage. The permeability under different confining pressures was different when the damage variable was approximate to 0.1. As the confining pressure increases, the permeability and the damage variable tend to be constant. The total permeability change is 0.568 when the confining pressure is 30 MPa. Moreover, a deviatoric stress threshold 0.8 $${\sigma }_{\rm p}$$ σ p is observed in the process of permeability evolution. When the applied stress is less than the threshold, the influence of confining pressure doesn’t play a dominant role in the permeability evolution. When the applied stress is larger than the threshold, the permeability evolution depends on the combination of axial stress and confining pressure. Hydrostatic compression loading and unloading, traditional triaxial compression, triaxial cyclic loading and unloading, and permeability integration test were carried out respectively. A deviatoric stress threshold $${\sigma }_{\rm p}$$ σ p is identified in permeability evolution. Both axial loading and confining pressure have significant effects on the permeability evolution when the stress larger than it. The relationship between the permeability evolution and the damage variables evolution is analyzed, and the results show that under low confining pressures, the influence of the damage variable on permeability evolution is significant. | An experimental investigation of gas permeability of a low permeability sandstone under deviatoric loading with loading/unloading cycles | 10.1007/s40948-023-00729-7 |
2023-12-22 | Purpose Orthodontics treatments (OT) cause temporary inflammatory response and consequently pain. Several meta-analyses have been conducted to address the effects of pharmacological and non-pharmacological approaches on pain management, however, the results are contradictory. Thus, present meta-analysis of meta-analyses was conducted to provide a definite conclusion on the efficacy of pharmacological and non-pharmacological approaches in pain management after OT. Methods Web of Science, PubMed, Scopus, Cochrane Central Library, and EMBASE were searched up to June 2023. All meta-analysis of controlled trials investigating the effect of ibuprofen and low level laser therapy (LLLT) on pain under OTs were included. General characteristics of the studies, effect sizes and confidence intervals were extracted. Random-effects model was used to estimate the pooled results. Subgroup and sensitivity analyses were also conducted. AMSTAR2 was used for quality assessment. Results Overall, 11 studies were included in this umbrella review among which 9 studies went under quantitative assessment. The results of six meta-analyses with 33 effect sizes indicated that LLLT was efficacious in reducing pain after OT (ES = − 3.52; 95% CI: -4.20, − 2.83, p = 0.20) (I 2 = 95.9%, p ≤ 0.001). Also, pooled analysis of 4 meta-analyses with 40 effect sizes showed that Ibuprofen significantly reduced pain after OT (ES = − 0.19; 95% CI: − 0.20, − 0.08, p ≤ 0.001) (I 2 = 64.5%, p ≤ 0.001). Conclusion The results support the use of LLLT and ibuprofen for the management of the pain after OT. | The effectiveness of low level laser therapy and ibuprofen in the management of pain during orthodontics treatments: a meta-analysis of meta-analyses | 10.1007/s41547-023-00207-z |
2023-12-22 | Background Braces have been a popular treatment option for scoliosis among healthcare professionals for many years. However, the effect of braces on scoliosis treatment remains a subject of ongoing debate and research. Aims Our study aimed to evaluate the effects of wearing a spinal brace on vertical jump, postural control, reach distance, and fall risk in patients with Adolescent Idiopathic Scoliosis (AIS). Methods We included 33 patients with AIS aged between 10 to 18 years old in our cross-sectional study. Patients were randomly subjected to vertical jump test, standing long jump test, timed up and go test, postural control, and forward reach test, while wearing and not wearing the scoliosis brace, respectively. Results Our findings revealed that patients wearing scoliosis braces had significantly lower vertical jumps (p = .001), standing long jumps (p < .001), and forward reach distances with their dominant (p = .002) and non-dominant limbs (p = .007) compared to those who did not wear the brace. However, there was no significant difference in postural control and timed up and go test between the two groups (p > .05). Conclusions Our study suggests that wearing a scoliosis brace may negatively affect an individual's vertical and standing long jumps, and forward reach distances. However, wearing or not wearing the brace had no significant effect on postural control and timed stand-up test. Long-term follow-up studies are needed to evaluate the overall effectiveness of scoliosis braces in treating AIS. | The acute effects of brace use on lower extremity performance in individuals with adolescent idiopathic scoliosis | 10.1007/s11845-023-03588-z |
2023-12-21 | Ambient pressure (AP)-dried polydicyclopentadiene (pDCPD) aerogels with low-cost, lightweight, and low thermal conductivity values were developed for the first time via simple sol-gel processing. Uniform pDCPD wet gels were first prepared at room temperature and atmospheric pressure through ring-opening metathesis polymerization (ROMP) incorporating homogeneous ruthenium catalyst complexes (i.e., Grubbs catalyst). Gelation kinetics were found to be significantly affected by both the catalyst content and the target density (i.e., solid content) while processing parameters such as reaction solvents, solvent exchange, and drying temperature played a significant role in determining the appearance and uniformity of wet gel and consequently, the AP-dried aerogel monolith and composite. Basic chemical and physical properties of AP-dried pDCPD aerogel products, including gelation kinetic, final density, shrinkage factor, porosity, thermal conductivity value, pore size, pore volume distribution, and pore morphologies, were measured and compared to the previously reported supercritical CO 2 -dried pDCPD aerogel. The AP-dried pDCPD aerogel showed very similar porosity, thermal conductivity values, pore size, and pore volume compared to supercritically dried pDCPD aerogels, although they showed a slightly higher shrinkage factor. From the scanning electron microscopy (SEM) images observed at high magnification, the AP-dried pDCPD aerogel monolith has a sharp, naturally grown crystal-like structure with nanoscale pores, while supercritical CO 2 -dried pDCPD aerogel monolith showed a sponge-like structure with a smooth surface, possibly due to the different pressure condition. The AP-dried pDCPD aerogels offer a potentially low-cost alternative to the current silica aerogel products as well as the many conventional inorganic and organic thermal and acoustic insulation materials. Graphical Abstract First to report pDCPD-based aerogel products fabricated by ambient pressure (AP) drying. AP-dried pDCPD aerogel shows similar properties as supercritical CO 2 -dried pDCPD aerogel. AP-dried pDCPD aerogel offers an alternative to silica aerogel and other insulation materials. | Ambient pressure dried polydicyclopentadiene based aerogels for low-cost lightweight thermal insulation materials | 10.1007/s10971-023-06285-6 |
2023-12-21 | Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) have attracted widespread concern due to their high toxicity, and their difficult manipulation in laboratories has made the research process tough. Thus, in our work, furan is selected as the model compound owing to the same structure of a central oxygenate ring. Although catalytic oxidation is regarded as an effective and applicable method for the abatement of PCDD/Fs, the synthesis of low-temperature catalysts is still a challenging problem in practical applications. Considering this situation, we prepared a novel V 2 O 5 /TiO 2 catalyst modified with N-doped hierarchical porous carbon (NHPC) via a wet impregnation method. The V/T-1%NHPC catalyst could achieve expectant low-temperature performances with 50% furan conversion at 150 °C and a complete conversion at 200 °C, which decreased 23 °C and 40 °C compared to the V/T catalyst respectively. Moreover, the addition of NHPC presented lifting chemical stability during long-time test. The addition of NHPC in V/T catalysts decreased the formation of crystalline V 2 O 5 and increased the percentages of V 5+ and O lat , which improved the utilization of vanadium ions and the catalytic activity. Simultaneously, the higher binding energy shift of O lat implied more reaction possibility with other oxidise reactants. Importantly, this work proved the lifting catalytic activity by the interaction between catalysts and NHPC, and proposed the promoting effects of the N element. The results showed that the content of the pyridinic N and graphitic N in NHPC changed after combining with V/T catalyst, which played crucial roles in the excellent catalytic performance. Overall, this work provides comprehensive research of the V/T-1%NHPC catalyst toward furan oxidation at low temperature and explain the effects of N-doped biomass carbon in catalytic activity clearly, which gave a new thought to design low-temperature catalysts in PCDD/Fs degradation. Besides, the internal functional mechanisms of N species are worth further exploration in future studies. Graphical abstract | Enhancing mechanisms of N-doped biomass carbon on the vanadium-based catalyst for furan degradation at low temperature | 10.1007/s42768-023-00172-0 |
2023-12-20 | Global symmetries of quantum many-body systems can be spontaneously broken. Whenever this mechanism happens, the ground state is degenerate and one encounters an ordered phase. In this study, our objective is to investigate this phenomenon by examining the entanglement asymmetry of a specific region. This quantity, which has recently been introduced in the context of U(1) symmetry breaking, is extended to encompass arbitrary finite groups G . We also establish a field theoretic framework in the replica theory using twist operators. We explicitly demonstrate our construction in the ordered phase of the Ising field theory in 1+1 dimensions, where a ℤ 2 symmetry is spontaneously broken, and we employ a form factor bootstrap approach to characterise a family of composite twist fields. Analytical predictions are provided for the entanglement asymmetry of an interval in the Ising model as the length of the interval becomes large. We also propose a general conjecture relating the entanglement asymmetry and the number of degenerate vacua, expected to be valid for a large class of states, and we prove it explicitly in some cases. | Entanglement asymmetry in the ordered phase of many-body systems: the Ising field theory | 10.1007/JHEP12(2023)144 |
2023-12-19 | Background 5-FU has multiple applications in various cancers but has limitations owing to its shorter half-life and rapid metabolism. In this study, injectable intratumoral gels were developed to enhance 5-FU concentrations in tumor vicinity. Sterile tunable poly (N-isopropylacrylamide)-based pH/thermo dual-sensitive self-assembled and in situ crosslinkable injectable depot gels with low viscous grade of chitosan (LVCS) were developed via cold and free radical polymerization method for localized and sustained delivery. Results Rheological analysis confirmed the gelation temperature, sol–gel transitions and viscoelastic behavior of in situ gels. Swelling–deswelling–reswelling cycles established the effect of temperature on structural changes. Swelling tests and in vitro drug release conducted in various dissolution media at variable temperatures confirmed pH/thermal dual response of formulations. Methyl thiazolyl tetrazolium assay confirmed that the hydrogels have good cytocompatibility with above 85% cells viability in Vero cells. In vitro cytotoxicity assay against MCF-7 cells displayed that 5-fluorouracil has good anticancer activity in loaded gel form as compared to free 5-FU. The cytotoxic studies showed that IPLVCS-2 and IPLVCS-6 have the highest inhibition (IC 50 = 47 ± 1 µg/ml, 34 ± 17 µg/ml) as compared to free 5-FU (IC 50 = 52 ± 3 µg/ml). Conclusion Current findings conclude that taking the advantage of physiologic environment acidic pH and high temperature of cancer cells, poly(NIPAAm)-g-LVCS formulations can effectively be used as intratumoral controlled depot of 5-FU. Graphical Abstract | Fabrication and evaluation of smart pH/thermo dual-responsive injectable intratumoral in situ depot hydrogels for controlled 5-FU delivery | 10.1186/s43088-023-00459-5 |
2023-12-19 | Linear low-density polyethylene (LLDPE) is a type of plastic with a high percentage of solid waste and is hardly degradable. The characteristics of LLDPE such as high toughness and low density have the potential to be an alternative aggregate substitute for applications in non-structural mortar composites. The purpose of this study was to determine the suitable formulation of LLDPE aggregate substitution against silica sand for the application of non-structural adhesive mortar composites. Vinyl acetate/ethylene (VAE) surfactant (1.2 wt%) was used to improve the interface between LLDPE and the cement matrix. Mechanical testing; XRD and FTIR characterization; density measurements; compression, adhesion, and thermogravimetric test; and morphological observation were carried out in this experiment. The results showed that LLDPE substitution decreased physical properties and accelerated thermal degradation. Cracks occurred on higher amount of LLDPE composition due to big difference in polarity. Suitable LLDPE substitution composition for adhesive mortar is up to 50%. Graphical Abstract | Mechanical and thermal properties of non-structural adhesive mortar using linear low-density polyethylene (LLDPE) aggregate substitution with vinyl acetate/ethylene (VAE) interface | 10.1007/s00396-023-05216-9 |
2023-12-19 | Abstract Mutations affecting T-cell receptor (TCR) signaling typically cause combined immunodeficiency (CID) due to varying degrees of disturbed T-cell homeostasis and differentiation. Here, we describe two cousins with CID due to a novel nonsense mutation in LCK and investigate the effect of this novel nonsense mutation on TCR signaling, T-cell function, and differentiation. Patients underwent clinical, genetic, and immunological investigations. The effect was addressed in primary cells and LCK-deficient T-cell lines after expression of mutated LCK. Results Both patients primarily presented with infections in early infancy. The LCK mutation led to reduced expression of a truncated LCK protein lacking a substantial part of the kinase domain and two critical regulatory tyrosine residues. T cells were oligoclonal, and especially naïve CD4 and CD8 T-cell counts were reduced, but regulatory and memory including circulating follicular helper T cells were less severely affected. A diagnostic hallmark of this immunodeficiency is the reduced surface expression of CD4. Despite severely impaired TCR signaling mTOR activation was partially preserved in patients’ T cells. LCK-deficient T-cell lines reconstituted with mutant LCK corroborated partially preserved signaling. Despite detectable differentiation of memory and effector T cells, their function was severely disturbed. NK cell cytotoxicity was unaffected. Residual TCR signaling in LCK deficiency allows for reduced, but detectable T-cell differentiation, while T-cell function is severely disturbed. Our findings expand the previous report on one single patient on the central role of LCK in human T-cell development and function. Graphical Abstract | Combined Immunodeficiency Caused by a Novel Nonsense Mutation in LCK | 10.1007/s10875-023-01614-4 |
2023-12-14 | Although most cucumber varieties have certain parthenocarpy abilities, fruit development will still be significantly inhibited at low temperature. Therefore, it is of great significance to study the molecular mechanism of parthenocarpy regulated by low temperature and to excavate low temperature-tolerant parthenocarpic gene resources, for stable production under low-temperature stress. ‘EC5’ is a low temperature-induced parthenocarpy (LT-P) line identified by previous screening. In this study, the effect of hormones on the development of the LT-P fruit was studied by transcriptome analysis and endogenous hormone determination under two different temperature conditions . It was found that there were few differentially expressed genes between ovaries before anthesis (230 ~ 460 DEGs). However, after anthesis, the number of DEGs increased sharply, following 1, 372 DEGs at 1 day after anthesis (DAA), 6, 272 DEGs at 2 DAA, and 9, 119 DEGs at 3 DAA, respectively. At 2 DAA, DEGs were significantly enriched in the plant hormone signal transduction pathway (Ko 04075); 25% and 19% of the genes were involved in auxin and ethylene metabolism and signaling, respectively. Endogenous hormone determination indicated that the accumulation of IAA and ACC showed an inverse curve during fruit development: IAA accumulated continuously, while ACC synthesis was inhibited during parthenocarpy under low temperature. During fruit abortion at room temperature, the IAA metabolism level decreased sharply, and ACC synthesis increased. Those were consistent with the results of transcriptome analysis that auxin-related genes were significantly up-regulated, and ethylene-related genes were significantly down-regulated. qRT-PCR analysis indicated that some key auxin-related genes had an opposite expression trend compared with ethylene-related genes under two temperature conditions. Exogenous applications of auxin and ethylene showed that auxin promoted parthenocarpy while ethylene inhibited parthenocarpy. In addition, hormone-responsive transcription factors were also actively expressed, among which the DEGs of auxin signal-responsive transcription factors AUX/IAA family and ethylene signal-responsive transcription factors AP2/ERF family were the largest. During the process of LT-P, 90% ~ 100% of AUX/IAA genes were up-regulated and 15% ~ 100% of AP2/ERF genes were down-regulated. This study verified that auxin and ethylene played important roles in the process of cucumber parthenocarpy under low-temperature stress, and it was speculated that auxin positively regulated parthenocarpic fruit development, whereas ethylene negatively correlated with the developmental process. | Auxin and Ethylene Play Important Roles in Parthenocarpy Under Low-Temperature Stress Revealed by Transcriptome Analysis in Cucumber (Cucumis sativus L.) | 10.1007/s00344-023-11172-z |
2023-12-14 | This work shows a 3-year climatology of the horizontal components of the solar diurnal tide, obtained from wind measurements made by a multistatic specular meteor radar (SIMONe) located in Jicamarca, Peru (12 $$^\circ$$ ∘ S, 77 $$^\circ$$ ∘ W). Our observations show that the meridional component is more intense than the zonal component, and that it exhibits its maxima shifted with respect to the equinox times (i.e., the largest peak occurs in August–September, and the second one in April–May). The zonal component only shows a clear maximum in August–September. This observational climatology is compared to a climatology obtained with the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension (WACCM-X). Average comparisons indicate that the model amplitudes are 50% smaller than the observed ones. The WACCM-X results are also used in combination with observed altitude profiles of the tidal phases to understand the relative contributions of migrating and non-migrating components. Based on this, we infer that the migrating diurnal tide (DW1) dominates in general, but that from June until September (November until July) the DE3 (DW2) may have a significant contribution to the zonal (meridional) component. Finally, applying wavelet analysis to the complex amplitude of the total diurnal tide, modulating periods between 5 and 80 days are observed in the SIMONe measurements and the WACCM-X model. These modulations might be associated to planetary waves and intraseasonal oscillations in the lower tropical atmosphere. Graphical Abstract | Climatology of mesosphere and lower thermosphere diurnal tides over Jicamarca (12
$$^\circ$$
∘
S, 77
$$^\circ$$
∘
W): observations and simulations | 10.1186/s40623-023-01935-z |
2023-12-14 | Purpose This study aims to describe clinical, virological and radiological characteristics as well as treatment strategies and outcomes of immunocompromised patients with persistent SARS-CoV-2 replication. Methods We performed a retrospective cohort study of immunocompromised patients at the University Medical Center Freiburg between 01/2022 and 05/2023. Patients with substantial immunosuppression and persistent SARS-CoV-2 detection (Ct-value < 30 after 14 days) were included. Results 36 patients in our cohort reported mainly fever, dyspnoea or continuous cough. Viral load was significantly higher in concurrent samples taken from the lower respiratory tract (Ct-value = 26) than from the upper respiratory tract (Ct-value = 34). Time of detectable viral RNA after start of antiviral treatment was shorter in patients receiving two antivirals (median 15 days vs. 31 days with one antiviral agent). Short-course antiviral therapy (≤ 5 days) was less efficient in reduction of symptoms and viral load than prolonged therapy > 10 days. In 30% (8/27) of patients with repeated CT scans, we found the emergence of chronic pulmonary changes, which were more frequently in patients with B cell depletion (37%, 7/19) compared to patients with organ transplantation (12%, 2/17). Conclusion Ongoing SARS-CoV-2 replication in the lower respiratory tract is a relevant differential diagnosis in patients with severe immunosuppression and continuous cough, fever or dyspnoea even if nasopharyngeal swabs test negative for SARS-CoV-2. Especially in B cell-depleted patients, this may lead to inflammatory or fibrotic-like pulmonary changes, which are partially reversible after inhibition of viral replication. Antiviral therapy seems to be most effective in combination and over a prolonged period of time of > 10 days. Trial registration number DRKS 00027299. | Clinical phenotype and outcome of persistent SARS-CoV-2 replication in immunocompromised hosts: a retrospective observational study in the Omicron era | 10.1007/s15010-023-02138-0 |
2023-12-14 | During the Late Permian Wuchiapingian–Changhsingian (W–C) transition, significant biotic and environmental changes occurred. These changes had the potential to greatly influence the type, accumulation, and preservation of organic matter within sediments during this period. The Wujiaping Formation, which acts as the contemporaneous heterotopic facie of the Longtan Formation, is regionally found in the Susong–Dongzhi stratigraphic subregion in the Lower Yangtze Platform (LYP). However, the variations in organic matter input and preservation during the Late Permian W–C transition in this specific area have not been comprehensively understood. Consequently, this study involved the collection of Upper Permian Wujiaping and Dalong shale samples in the LYP. Total organic carbon (TOC) content, vitrinite reflectance ( R o ), maceral compositions, carbon isotope composition of kerogen, as well as the major and trace elements in the shale samples were all measured in this study. The results of R o analysis indicate that the maturity levels of shale derived from the Dalong and Wujiaping Formations exhibit maturity levels exceeding 2%, which indicates an over-mature stage. The maceral compositions and carbon isotope analysis of kerogen reveal that the predominant source of organic matter within the Dalong shale is attributed to algal organism. Conversely, the organic matter in the Wujiaping shale primarily comes from higher plants. The major and trace element distributions provide insights into the depositional conditions of the Upper Permian shale, and significant variations in organic matter input and preservation are evident during the Late Permian W–C transition. The findings indicate that the Wujiaping Formation was characterized by a low paleo-productivity, high terrestrial influx intensity, low paleo-salinity, and a pronounced restricted setting under oxic conditions. However, the Dalong Formation is deposited under an anoxic environment, characterized by high paleo-productivity and paleo-salinity, limited terrestrial influx intensity, and increasing upwelling. In addition, the water mass restriction weakened within the Dalong Formation, attributable to a gradual rise in sea level. The shift of organic matter input and preservation was instigated by the persistent regional rise in the sea level during the Late Permian period. In summary, the great input and favorable preservation conditions of organic matter observed in the Dalong shale indicates a promising potential for shale gas exploration. Graphical abstract | Input and preservation of organic matter in the Upper Permian shale from the Lower Yangtze Platform, South China: evidence from organic and inorganic geochemistry | 10.1007/s00531-023-02369-4 |
2023-12-13 | This paper is concerned with the influence of cooling rate after thermomechanical processing and subsequent annealing temperature on the microstructure, tensile and low-cycle fatigue properties of Ti-6242S alloy. First, two rectangular cross-sectional profiles of the alloy hot rolled at 940 °C and separately cooled in water and air media while other thermomechanical parameters including rolling temperature, total strain, and the number of rolling passes were same. Subsequently, the profiles were divided to two sections and annealed at 940 and 970 °C for 1 hour and immediately water quenched. Eventually, all the specimens were aged at 600 °C for 8 hour and air-cooled. According to the microstructural evaluation, it was revealed that an increase in cooling rate after hot-rolling led to an increment in recrystallization and globalization and the lower average grain size of α -phase. By solution annealing the alloy at 970 °C, the elongated α -phases converted to the smaller and granular α -phase and higher thickness of secondary α -phase achieved. At the same annealing temperature, cooling in the air brought about a higher yield stress, ultimate tensile stress at both 25 and 480 °C. However, in the same cooling environment, the specimens annealed at higher temperatures owned higher tensile stresses and better elongation. For both cooling media of rolling process, increasing in subsequent annealing temperature from 940 to 970 °C associated improving fatigue life and higher stress amplitudes. | The Effect of Annealing Temperature on Low-Cycle Fatigue Properties of Thermomechanically Processed Ti-6242S Alloy | 10.1007/s11665-023-09029-3 |
2023-12-13 | Concrete structures in cold and moderate climates are often exposed to a combined salt frost attack, which can cause scaling damage. Consequently, numerous test procedures were developed to determine the resistance of concrete compositions against this kind of attack. These tests mimic a severe attack with high levels of saturation, which is typical for horizontal concrete elements or structures, such as concrete pavements. Very few approaches exist for testing the salt frost scaling resistance of concretes for vertical concrete elements like bridge columns, which are subjected to only moderate levels of saturation during salt frost attack (exposure class XF2). As such elements usually didn’t show notable scaling damage in practice, this hasn’t posed a problem until recently. However, the increasing use of low carbon cements with high clinker substitution rates might increase the vulnerability against salt frost exposure for such concrete elements to some extent. To ensure adequate durability it is desirable to determine the performance of the concrete in an actual test procedure instead of relying on descriptive criteria alone. Thus, a less severe test method was developed, which is based on the CDF test. It was shown that the modified test procedure can distinguish correctly between different concrete qualities. Furthermore, the applicability of an acceptance criterion for the method was investigated. | Alternative salt frost scaling test procedure for exposure class XF2 | 10.1617/s11527-023-02278-7 |
2023-12-13 | The Naozhi deposit of northeast China comprises intermediate-sulfidation epithermal-style veins and subeconomic, porphyry-style Cu mineralization hosted by dioritic to granitic plutons, which formed at ca. 130 Ma. These intrusive phases were fed by magmas that ponded at mid- to upper-crustal levels and were finally emplaced at < 0.6 kbar based on amphibole geobarometry. The magmas were moderately oxidized (∆NNO − 0.35 to 2.21; with NNO being the nickel–nickel–oxide buffer) and water-rich (mostly > 4 wt. %), and likely experienced a relatively prolonged evolution in the shallow crust rather than at depth. Magma devolatilization and fluid exsolution at shallow-crustal levels lead to decreases in both oxygen fugacity (log ƒO 2 − 10.96 to − 14.13) and water content (6.53 to 2.26 wt. %) at < 2.5 kbar pressures. Thermochronological data of zircon and apatite, thermal history modeling, and geological preservation record complex time–temperature histories of the mineralized intrusive rocks, from the cooling of the parent magma itself through burial by younger volcanic rocks to protracted erosion with time. It is estimated that < 2 km of pre-mineralization material was removed from the top of the Naozhi magmatic–hydrothermal system from the Early Cretaceous to present. A 108 ± 2 Ma volcanic event possibly tilted the hydrothermal system, but buried the ores, protecting them from extensive erosion. | Evolution and exhumation of intrusive rocks associated with the Naozhi porphyry–epithermal system, NE China | 10.1007/s00410-023-02079-9 |
2023-12-12 | Human enteric viruses are important etiological agents of waterborne diseases. Environmental waters are usually contaminated with low virus concentration requiring large concentration factors for effective detection by (RT)-qPCR. Low-pressure reverse osmosis is often used to remove water contaminants, but very few studies focused on the effective virus removal of reverse osmosis treatment with feed concentrations as close as possible to environmental concentrations and principally relied on theoretical virus removal. The very low viral concentrations usually reported in the permeates (i.e. at least 5 log of removal rate) mean that very large volumes of water need to be analysed to have sufficient sensitivity and assess the process efficiency. This study evaluates two methods for the concentration of adenoviruses, enteroviruses and MS2 bacteriophages at different viral concentrations in large (< 200 L) and very large (> 200 L) volumes. The first method is composed of two ultrafiltration membranes with low-molecular weight cut-offs while the second method primarily relies on adsorption and elution phases using electropositive-charged filters. The recovery rates were assessed for both methods. For the ultrafiltration-based protocol, recovery rates were similar for each virus studied: 80% on average at high virus concentrations (10 6 –10 7 viruses L −1 ) and 50% at low virus concentrations (10 3 –10 4 viruses L −1 ). For the electropositive-charged filter-based method, the average recoveries obtained were about 36% for ADV 41, 57% for CV-B5 and 1.6% for MS2. The ultrafiltration-based method was then used to evaluate the performance of a low-pressure reverse osmosis lab-scale pilot plant. The retentions by reverse osmosis were similar for all studied viruses and the validated recovery rates applied to the system confirmed the reliability of the concentration method. This method was effective in concentrating all three viruses over a wide range of viral concentrations. Moreover, the second concentration method using electropositive-charged filters was studied, allowing the filtration of larger volumes of permeate from a semi-industrial low-pressure reverse osmosis pilot plant. This reference method was used because of the inability of the UF method to filter volumes on the order of one cubic metre. | Implementation of a Sensitive Method to Assess High Virus Retention Performance of Low-Pressure Reverse Osmosis Process | 10.1007/s12560-023-09570-3 |
2023-12-11 | Low coercive ZnMnFe ceramics was obtained on the basis of nanocrystalline ferrite pre-ceramic powders synthesized by glycine-nitrate combustion method. The effect of synthesis parameters on the formation and microstructure of pre-ceramic powders and elemental composition and sintering conditions on the phase purity and magnetic properties of ceramics were investigated by scanning electron microscopy, X-ray diffraction and vibrating sample magnetometry. Based on the initial powders with average crystal size is in the range of 41 ± 2 nm, ceramics with a grain size of 10 ± 5 μm were obtained. The approach used in the work made it possible to obtain single-phase Zn x Mn (1-x) Fe 2 О 4 ceramics with Mn content of up to 0.7 in an air atmosphere. It was found that single-phase ferrite ceramics demonstrates high values of magnetic characteristics. These ceramic materials exhibited exceptionally low H c of up to 66.99 А/m (0.84 Oe) and high B s of up to 0.293 T and B r of up to 0.122 T. High temperature X-ray diffraction analysis was used to simulate sintering conditions and determine their influence on the phase composition and magnetic properties of ceramics. Graphical Abstract Single-phase ferrite ceramics obtained in an air atmosphere based on Zn x Mn (1-x) Fe 2 О 4 nanopowders. Phase composition and magnetic properties of ceramics can be controlled by sintering parameters. A technology for obtaining ferrite ceramics with high-quality magnetic properties is presented. | An alternative approach to obtaining low coercivity ZnMn ferrite ceramics with the use of solution combustion method: effect of sintering conditions on structural, morphological and magnetic parameters | 10.1007/s10971-023-06284-7 |
2023-12-11 | The traditional ironmaking technologies (including coking, sintering, pelletizing, and BF ironmaking process) are carbon-intensive, which makes the industry a significant contributor to global CO 2 emissions. Hydrogen replacement of carbon in steelmaking processes is a sustainable way to reduce CO 2 emissions. First, the reduction thermodynamics and kinetics of iron oxide by carbon and hydrogen are compared. Then, the latest researches on different hydrogen reduction technologies in ironmaking industry are compared and analyzed. Based on this, the advantages and problems faced by hydrogen-based reduction over carbon-based reduction are presented. And finally, the possible pathways for the future development of hydrogen metallurgy are proposed, hoping to provide guidance for the hydrogen metallurgy in the steel industry. The reduction product of hydrogen metallurgy is H 2 O, and has a faster reduction rate than CO reduction. Therefore, hydrogen metallurgy is considered to be an effective way to achieve low-carbon green transformation in the metallurgical industry. Graphical Abstract | Hydrogen-Based Reduction Technologies in Low-Carbon Sustainable Ironmaking and Steelmaking: A Review | 10.1007/s40831-023-00772-4 |
2023-12-11 | Climate change has always been a core issue in the field of agricultural security. From the perspective of “passive adaptation” and “active change,” climate response is manifested as climate “adaptation behavior” and “low carbon and pro-environment behavior” respectively. In the long run, low carbon and pro-environment behavior make more sense. As an indispensable part of the modern agricultural management system, agricultural enterprises are the core power to promote the organic reorganization of various agricultural production factors, and the optimal low carbon and pro-environmental behavior is the key to the implementation of national ecological environmental protection policies. The purpose of this paper is to reveal the mechanism of pro-environment behavior of organization members based on the organizational background of agricultural enterprises. Taking advantage of 189 valid survey data of agricultural enterprises, structural equation model was used to explore the effects of organizational commitment and role models’ guidance on low carbon and pro-environment behavior. Results show that organizational commitment has a significant positive effect on the low carbon and pro-environment behavior of agricultural enterprises. And what is not expected is that role models’ guidance has a significant negative effect on the low carbon and pro-environment behavior of agricultural enterprises, and organizational commitment has a negative impact on the low carbon and pro-environment behavior of agricultural enterprises through role models’ guidance. Recommendations such as practicing green culture and enhancing emotional engagement; fostering social responsibility and strengthening normative commitment; providing a fair path and increasing the influence of role models; improving the selection system of role models and also the criteria; improving the level of leadership and achieving high quality interaction or creating a business environment are proposed. | Analyzing the low carbon and pro-environment behavior of agricultural enterprises based on organizational commitment and role models’ guidance | 10.1007/s11356-023-31302-0 |
2023-12-11 | Background Several trials and meta-analyses found a benefit of adjunct corticosteroids for community-acquired pneumonia with respect to short-term outcome, but there is uncertainty about longer-term health effects. Herein, we evaluated clinical outcomes at long term in patients participating in the STEP trial (Corticosteroid Treatment for Community-Acquired Pneumonia). Methods This predefined secondary analysis investigated 180-day outcomes in 785 adult patients hospitalized with community-acquired pneumonia included in STEP, a randomised, placebo-controlled, double-blind trial. The primary endpoint was time to death from any cause at 180 days verified by telephone interview. Additional secondary endpoints included pneumonia-related death, readmission, recurrent pneumonia, secondary infections, new hypertension, and new insulin dependence. Results From the originally included 785 patients, 727 were available for intention-to-treat analysis at day 180. There was no difference between groups with respect to time to death from any cause (HR for corticosteroid use 1.15, 95% CI 0.68 to 1.95, p = 0.601). Compared to placebo, corticosteroid-treated patients had significantly higher risks for recurrent pneumonia (OR 2.57, 95% CI 1.29 to 5.12, p = 0.007), secondary infections (OR 1.94, 95% CI 1.25 to 3.03, p = 0.003) and new insulin dependence (OR 8.73, 95% CI 1.10 to 69.62, p = 0.041). There was no difference regarding pneumonia-related death, readmission and new hypertension. Conclusions In patients with community-acquired pneumonia, corticosteroid use was associated with an increased risk for recurrent pneumonia, secondary infections and new insulin dependence at 180 days. Currently, it is uncertain whether these long-term adverse effects outweigh the short-term effects of corticosteroids in moderate CAP. Trial registration This trial was registered with ClinicalTrials. gov, number NCT00973154 before the recruitment of the first patient. First posted: September 9, 2009. Last update posted: April 21, 2015. | Adjunct prednisone in community-acquired pneumonia: 180-day outcome of a multicentre, double-blind, randomized, placebo-controlled trial | 10.1186/s12890-023-02794-w |
2023-12-09 | Background Commercial anti-CD19 chimeric antigen receptor T-cell therapies (CART19) are efficacious against advanced B-cell non-Hodgkin lymphoma (NHL); however, most patients ultimately relapse. Several mechanisms contribute to this failure, including CD19-negative escape and CAR T dysfunction. All four commercial CART19 products utilize the FMC63 single-chain variable fragment (scFv) specific to a CD19 membrane-distal epitope and characterized by slow association (on) and dissociation (off) rates. We hypothesized that a novel anti-CD19 scFv that engages an alternative CD19 membrane-proximal epitope independent of FMC63 and that is characterized by faster on- and off-rates could mitigate CART19 failure and improve clinical efficacy. Methods We developed an autologous CART19 product with 4-1BB co-stimulation using a novel humanized chicken antibody (h1218). This antibody is specific to a membrane-proximal CD19 epitope and harbors faster on/off rates compared to FMC63. We tested h1218-CART19 in vitro and in vivo using FMC63-CART19-resistant models. We conducted a first-in-human multi-center phase I clinical trial to test AT101 (clinical-grade h1218-CART19) in patients with relapsed or refractory (r/r) NHL. Results Preclinically, h1218- but not FMC63-CART19 were able to effectively eradicate lymphomas expressing CD19 point mutations (L174V and R163L) or co-expressing FMC63-CAR19 as found in patients relapsing after FMC63-CART19. Furthermore, h1218-CART19 exhibited enhanced killing of B-cell malignancies in vitro and in vivo compared with FMC63-CART19. Mechanistically, we found that h1218-CART19 had reduced activation-induced cell death (AICD) and enhanced expansion compared to FMC63-CART19 owing to faster on- and off-rates. Based on these preclinical results, we performed a phase I dose-escalation trial, testing three dose levels (DL) of AT101 (the GMP version of h1218) using a 3 + 3 design. In 12 treated patients (7 DLBCL, 3 FL, 1 MCL, and 1 MZL), AT101 showed a promising safety profile with 8.3% grade 3 CRS ( n = 1) and 8.3% grade 4 ICANS ( n = 1). In the whole cohort, the overall response rate was 91.7%, with a complete response rate of 75.0%, which improved to 100% in DL-2 and -3. AT101 expansion correlates with CR and B-cell aplasia. Conclusions We developed a novel, safe, and potent CART19 product that recognizes a membrane-proximal domain of CD19 with fast on- and off-rates and showed significant efficacy and promising safety in patients with relapsed B-cell NHL. Trial registration NCT05338931; Date: 2022–04-01. | Safety and efficacy of a novel anti-CD19 chimeric antigen receptor T cell product targeting a membrane-proximal domain of CD19 with fast on- and off-rates against non-Hodgkin lymphoma: a first-in-human study | 10.1186/s12943-023-01886-9 |
2023-12-09 | Background Coronavirus Disease 2019 (COVID-19) is a novel respiratory disease that first emerged in 2019. Patients infected with this disease present with a myriad of symptoms. Limb ischemia and hypercoagulability are complications identified in adults. COVID-19-related vasculitis is a known but seldom reported complication in pediatric patients, and the treatment approach is still not well established. Case presentation We report the case of a healthy four-year-old female with a history of COVID-19 who developed acute lower limb ischemia. This was initially treated as a case of acute snake envenomation by administering snake antivenom with no improvement. She eventually developed lower limb acrocyanosis with an inability to ambulate. The patient was started on interleukin-6 receptor inhibitors (tocilizumab), anticoagulants, and pulse steroid therapy. The patient had complete resolution with the loss of only one toe. Conclusion Identification of thromboembolic complications in pediatric patients with no comorbidities and a history of COVID-19 can be difficult. Early recognition and treatment have a major impact on morbidity and can increase the likelihood of limb salvage. | A rare complication of acute lower limb ischemia post coronavirus disease 2019 infection in a healthy pediatric patient: case report | 10.1186/s12887-023-04454-8 |
2023-12-08 | Background The aim of this study was to compare the microstrain transmitted to peri-implant tissues of implant-assisted mandibular overdentures using two different low-profile attachment designs; OT- Equator attachment with and without bar attachment. Materials and methods A completely edentulous epoxy resin mandibular model was used, in which two parallel dental implants were inserted at the canine region bilaterally and one in the middle. Sixteen identical complete edentulous mandibular overdentures were fabricated following conventional, standardized techniques and were divided equally between two groups according to the design and placement of the OT-Equator. Group A implants were kept solitary with an OT-Equator attachment, while group B implants were kept splinted with a bar associated with two mini-OT-Equator attachments in between. Sixteen identical mandibular complete overdentures were constructed, to which attachments were picked up. The difference in stress distribution was measured using strain gauges and compared between the two studied groups. A vertical load of 100 N using the universal testing machine was applied unilaterally on the left mesial fossae of the mandibular first molar and bilaterally on the bar attached to the mandibular premolar molar region of the overdentures. Statistical analysis was conducted using IBM SPSS version 28. Normality was checked by using the Shapiro-Wilk test and normality plots. The Mann-Whitney U test was then used to analogize the groups. Results There was a statistically significant difference between groups A and B upon application of vertical unilateral and bilateral loadings of 100 N, with mean microstrain values of P 0.05. Group A (OT-Equator attachment) showed lower strain values than Group B (OT-Equator bar attachment) upon application of vertical, unilateral, and bilateral loadings of 100 N. Conclusions Implant-assisted mandibular overdenture with a solitary attachment is associated with lower microstrain values around the implants after application of unilateral and bilateral vertical loadings of 100 N. | A comparative study to evaluate microstrain of low-profile attachment associated with and without bar connection in implant assisted mandibular overdenture (in vitro study) | 10.1186/s12903-023-03702-8 |
2023-12-07 | Background The RNA recognition motif (RRM) is primarily engaged in the processing of mRNA and rRNA following gene transcription as well as the regulation of RNA transport; it is critical in preserving RNA stability. Results In this study, we identified 102 members of the RRM1 gene family in Brassica rapa , which were dispersed across 10 chromosomes with the ninth chromosome being the most extensively distributed. The RRM1 gene family members of Brassica rapa and Arabidopsis thaliana were grouped into 14 subclades (I–XIV) using phylogenetic analysis. Moreover, the results of transcriptome analysis and RT-qPCR indicated that the expression of Brapa05T000840 was upregulated in the cultivars ‘Longyou 7’ and ‘Longyou 99’ following exposure to cold stress at a temperature of 4 °C for 24 h. The levels of expression in the leaves and growth cones of the ‘Longyou 7’ variety were found to be significantly higher than those observed in the ‘Longyou 99’ variety under conditions of low temperature and NaCl stress. It illustrates the involvement of the RRM1 gene in the physiological response to both low temperature and salt stress. In addition, it was observed that the survival rate of transgenic BrRBP (Brapa05T000840) Arabidopsis thaliana plants was notably higher compared to that of wild-type plants when subjected to varying durations of low temperature treatment. Furthermore, the expression of the BrRBP gene in transgenic plants exhibited an upward trend as the duration of low temperature treatment increased, reaching its peak at 24 h. The in-vivo enzymatic activity of reactive oxygen species-scavenging enzymes were found to be significantly elevated in comparison to wild-type plants, suggesting that the BrRBP gene may enhance the cold tolerance of Arabidopsis thaliana . Conclusions This study offers a significant foundation for comprehending the regulation mechanism of the RRM1 gene family in winter Brassica rapa subjected to cold stress, as well as for finding key genes associated with cold resistance. | Genome-wide identification of RNA recognition motif (RRM1) in Brassica rapa and functional analysis of RNA-binding protein (BrRBP) under low-temperature stress | 10.1186/s12870-023-04639-4 |
2023-12-07 | Objective This prospective trial aimed to evaluate the effects of low-dose intravenous norepinephrine (NE) on intraoperative blood loss and bleeding from osteotomy sites during non-tourniquet total knee arthroplasty (TKA) under general anesthesia. Methods A total of 120 patients who underwent TKA between December 2020 and May 2022 were enrolled and randomly assigned to the intravenous low-dose NE Group (NE Group) or the control group (C Group). During surgery, NE Group received 0.05–0.1 μg/(kg min) of NE intravenously to raise and maintain the patient's mean arterial pressure (MAP). C Group received the same dose of saline as placebo. Intraoperative blood loss, bleeding score at osteotomy sites, Δlactate levels (Lac), postoperative complications, and transfusion rate during hospitalization were compared between groups. Results Intraoperative and osteotomy blood loss was significantly lower in the NE Group than in the C Group ( P < 0.001). No significant difference was observed in ΔLac between groups ( P > 0.05). There was no significant difference in complications between the groups 3 days after surgery ( P > 0.05). In addition, there was no significant difference in blood transfusion rates between the two groups during hospitalization ( P > 0.05). Conclusion In non-tourniquet TKA under general anesthesia, low-dose intravenous NE safely and effectively reduced intraoperative blood loss and provided a satisfactory osteotomy site while maintaining a higher MAP. | Effect of intravenous low-dose norepinephrine on blood loss in non-tourniquet total knee arthroplasty under general anesthesia: a randomized, double-blind, controlled, single-center trial | 10.1186/s13018-023-04360-w |
2023-12-06 | In August 2021, rain front stagnation in Japan resulted in prolonged and disastrous rainfall across the entire country. During the heavy rainfall period, the large-scale atmospheric field over the East Asian–western North Pacific region was characterized by meridional tripolar circulation anomalies: the Okhotsk high (OH), the trough over the Korean Peninsula (Korean trough), and the northwestern Pacific subtropical high (NWPSH). Simultaneously, tropical convective activity was enhanced over the eastern Indian Ocean and suppressed over the tropical western–central Pacific. This study investigates the dynamic mechanism of linkage of the extratropical tripolar anomalies and the effects of tropical convective modulation using a reanalysis dataset, a cutoff low detection scheme, the potential vorticity inversion method, and numerical experiments. Upper-tropospheric blocking over eastern Siberia connected to the surface OH is conducive to the stagnation of synoptic depressions, including cutoff lows and troughs, over the Korean Peninsula, contributing to the development and maintenance of the quasi-stationary Korean trough. Rossby waves emanating from the Korean trough excite an anticyclonic anomaly over the northwestern Pacific. This upper-level anomalous anticyclone acts to enhance the surface NWPSH through zonal heat transport, accompanied by a northward tilting structure with height. Simultaneously, the tropical intraseasonal oscillation is amplified over the Indo–western Pacific Ocean sector under the negative-phase Indian Ocean dipole and multi-year La Niña conditions. The combination of enhanced convection over the eastern Indian Ocean and suppressed convection across the tropical western–central Pacific reinforces the NWPSH. The anomalous circulation associated with the extratropical tripolar pattern and concurrent tropical heat forcing causes more moisture transport, convergence, and anomalous ascent, which contribute to heavy rainfall in Japan. These results suggest that the dynamically correlated amplification of tropical and extratropical circulation anomalies plays a crucial role in precipitation variability in East Asia. | Coherent amplification of the Okhotsk high, Korean trough, and northwestern Pacific subtropical high during heavy rainfall over Japan in August 2021 | 10.1186/s40645-023-00598-4 |
2023-12-06 | Abstract The paper examines pre-combustion carbon capture technology (PreCCS) for liquefied natural gas (LNG) propelled shipping from thermodynamics and energy efficiency perspectives. Various types of LNG reformers and CCS units are considered. The steam methane reformer (SMR) was found to be 20% more energy efficient than autothermal (ATR) and methane pyrolysis (MPR) reactors. Pressure swing adsorption (PSA) had a lower energy requirement than membrane separation (MEM), cryogenic separation (CS), and amine absorption (AA) in pre-combustion carbon capture, with PSA needing 0.18 kWh/kg CO 2 . An integrated system combining SMR and PSA was proposed using waste heat recovery (WHR) from the engine, assuming similar efficiency for LNG and H 2 operation, and cooling and liquefying of the CO 2 by the LNG. The SMR-PSA system without WHR had an overall efficiency of 33.4% (defined as work at the propeller divided by the total LNG energy consumption). This was improved to 41.7% with WHR and gave a 65% CO 2 emission reduction. For a higher CO 2 reduction, CCS from the SMR heater could additionally be employed, giving a maximum CO 2 removal rate of 86.2% with 39% overall energy efficiency. By comparison, an amine-based post-engine CCS system without reforming could reach similar CO 2 removal rates but with 36.6% overall efficiency. The advantages and disadvantages and technology readiness level of PreCCS for onboard operation are discussed. This study offers evidence that pre-combustion CCS can be a serious contender for maritime propulsion decarbonization. Graphical Abstract | A Thermodynamics Model for the Assessment and Optimisation of Onboard Natural Gas Reforming and Carbon Capture | 10.1007/s40825-023-00234-z |
2023-12-06 | Background Ischemic stroke is a serious disease leading to significant disability in humans worldwide. Increasing evidence suggests that some microRNAs (miRNAs) participate in the pathophysiology of ischemic stroke. A key role for MiR-212 has been found in neuronal function and synaptic plasticity. Ischemic stroke can be effectively treated with electroacupuncture (EA); however, there is a lack of understanding of the relevant mechanisms. In this study, we employed behavioral test and resting-state functional magnetic resonance imaging (rs-fMRI) to detect behavioral and brain function alterations in rats suffering from ischemic stroke. The efficacy of EA therapy and miR-212-5p’s role in this process were also evaluated. Methods and results Forty rats were randomly divided into the following groups: Sham, middle cerebral artery occlusion/reperfusion (MCAO/R), MCAO/R + EA, MCAO/R + EA + antagomir-negative control and MCAO/R + EA + antagomir-212-5p groups. Behavioral changes were assessed by Catwalk gait analysis prior to and after modeling. Rs-fMRI was performed at one week after EA treatment, amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were calculated to reveal neural activity. Furthermore, neuronal apoptosis in the ischemic penumbra was analyzed using a TUNEL assay. Treatment with EA significantly improved the performance of rats in the behavioral test. The motor and cognition-related brain regions showed decreased ALFF and ReHo following focal cerebral ischemia-reperfusion, and EA treatment could reactivate these brain regions. Moreover, EA treatment significantly decreased MCAO/R-induced cell death. However, the transfection of antagomir-212-5p attenuated the therapeutic effect of EA. Conclusions In conclusion, the results suggested that EA improved the behavioral and imaging outcomes of ischemic stroke through miR-212-5p. | Effects of electroacupuncture on imaging and behavior in rats with ischemic stroke through miR-212-5p | 10.1186/s12868-023-00827-y |
2023-12-05 | Background Active hydrothermal vents create extreme conditions characterized by high temperatures, low pH levels, and elevated concentrations of heavy metals and other trace elements. These conditions support unique ecosystems where chemolithoautotrophs serve as primary producers. The steep temperature and pH gradients from the vent mouth to its periphery provide a wide range of microhabitats for these specialized microorganisms. However, their metabolic functions, adaptations in response to these gradients, and coping mechanisms under extreme conditions remain areas of limited knowledge. In this study, we conducted temperature gradient incubations of hydrothermal fluids from moderate (pH = 5.6) and extremely (pH = 2.2) acidic vents. Combining the DNA-stable isotope probing technique and subsequent metagenomics, we identified active chemolithoautotrophs under different temperature and pH conditions and analyzed their specific metabolic mechanisms. Results We found that the carbon fixation activities of Nautiliales in vent fluids were significantly increased from 45 to 65 °C under moderately acidic condition, while their heat tolerance was reduced under extremely acidic conditions. In contrast, Campylobacterales actively fixed carbon under both moderately and extremely acidic conditions under 30 − 45 °C. Compared to Campylobacterales , Nautiliales were found to lack the Sox sulfur oxidation system and instead use NAD(H)-linked glutamate dehydrogenase to boost the reverse tricarboxylic acid (rTCA) cycle. Additionally, they exhibit a high genetic potential for high activity of cytochrome bd ubiquinol oxidase in oxygen respiration and hydrogen oxidation at high temperatures. In terms of high-temperature adaption, the rgy gene plays a critical role in Nautiliales by maintaining DNA stability at high temperature. Genes encoding proteins involved in proton export, including the membrane arm subunits of proton-pumping NADH: ubiquinone oxidoreductase, K + accumulation, selective transport of charged molecules, permease regulation, and formation of the permeability barrier of bacterial outer membranes, play essential roles in enabling Campylobacterales to adapt to extremely acidic conditions. Conclusions Our study provides in-depth insights into how high temperature and low pH impact the metabolic processes of energy and main elements in chemolithoautotrophs living in hydrothermal ecosystems, as well as the mechanisms they use to adapt to the extreme hydrothermal conditions. Video Abstract | Strategies of chemolithoautotrophs adapting to high temperature and extremely acidic conditions in a shallow hydrothermal ecosystem | 10.1186/s40168-023-01712-w |
2023-12-05 | In this paper, the Ca 2+ ion was chosen to substitute the Mg 2+ ion of Li 2 MgSiO 4 ceramics. Li 2 Mg 1 − x Ca x SiO 4 (x = 0.0, 0.03, 0.06, 0.09, 0.12) ceramics materials were prepared by solid state reaction at low temperature (925 °C) with 2.5wt% Bi 2 O 3 sintering aid. X-ray diffraction (XRD) results showed the ceramics presented the standard Lithium Magnesium Silicate phase formation, and no secondary phases appeared. Scanning electron microscopy (SEM) suggested that Ca 2+ ions affected the densification of the prepared ceramics. Ca 2+ ion substitution resulted in increasing relative density, enhancing microwave properties. Ca 2+ ion substituted Mg 2+ ion and formed a CaO4 structure, which affected microwave dielectric properties. With the substituted amount increase, the values of dielectric constant ε’ and quality factor Q×f gradually increased, and τ f values increased from negative to positive values. When x = 0.09 and sintered at 925 °C, Ca 2+ ion substitution gave ceramics excellent microwave properties: bulk density ρ = 2.479 g/cm 3 , relative density was 98.68%, dielectric constant ε’=6.59, dielectric loss tanδ ε = 0.0018, quality factor Q×f = 8976.9 GHz and temperature coefficient τ f = 1.9 ppm/°C. This ceramic material has excellent microwave dielectric properties and holds a potential for use in integrated antenna and other electronic devices. | Enhanced structure and microwave dielectric properties of low-temperature sintering Li2Mg1 − xCaxSiO4 ceramics by Ca2+ ion substitution | 10.1007/s10832-023-00342-w |
2023-12-05 | Tornadoes are the most violent and destructive of all the severe weather phenomena that localized convective storms produce. There is a requirement in operational meteorology increasing nowadays that an indicator index which allows to reduce the uncertainty of severe convective storms and tornadoes in the scope of climate change adaptation strategies. The main intention is not to replace or substitute mesoscale modeling approaches, or composite indexes, but to warn operationally to draw attention to the Eastern Mediterranean and Türkiye in particular a few days in advance. The development of some indicators using atmospheric variables can undertake a crucial role by enabling such numerical models to be run only at certain time intervals, thus enduring lower computational costs. In this study, Eastern Mediterranean oscillation index (EMEDOi) has been developed in order to be able to detect the presence of ULLs (upper-level low) and frontogenesis approach is employed for selected tornadic storm events in Türkiye. EMEDOi has 7 different its variations (members) which these members have been developed to detect differences depending on the entry directions of cyclones and storms influencing Türkiye from the west of the country. In line with the GDAS data analysis, values of geopotential height are derived for the requirement of EMEDOi in a limited area. A few of the results from the study are as in the following: 86% of the trained tornado events revealed that the EMEDO-Oper index was in negative phase at the time a tornado was reported, regardless of whether the events featured a supercell mesoscale convective storm or a frontal movement. The hourly period until the local minimum is obtained can be described and characterized as the process by which the EMEDO-Oper index value decreases continuously. The time required to reach the local minimum varies based on the tornado occurrence. Based on the tornadic storm scenario in the test cluster in 2022 and the train cluster, this timeframe is predicted to be roughly 33.2 h on average. In western Türkiye, there is a 79% chance of a tornado occurring between six and forty-two hours after the EMEDO-Oper index reaches its local minimum. In particular, the projected chance for this period is 63% between 12 and 30 h after the local minimum is obtained. Besides, the majority of the tornado incidents with EMEDO-Oper values below − 0.75 were evaluated. After an EMEDO-Oper index value falls below that threshold, it is likely to forecast the risk period of a tornado in Türkiye with a probability of 79% and the local minimum point must be identified. | An early indicator index of tornadic storms for Euro-Mediterranean region | 10.1007/s11069-023-06326-x |
2023-12-05 | Background DNA methylation, instrumental in numerous life processes, underscores the paramount importance of its accurate prediction. Recent studies suggest that deep learning, due to its capacity to extract profound insights, provides a more precise DNA methylation prediction. However, issues related to the stability and generalization performance of these models persist. Results In this study, we introduce an efficient and stable DNA methylation prediction model. This model incorporates a feature fusion approach, adaptive feature correction technology, and a contrastive learning strategy. The proposed model presents several advantages. First, DNA sequences are encoded at four levels to comprehensively capture intricate information across multi-scale and low-span features. Second, we design a sequence-specific feature correction module that adaptively adjusts the weights of sequence features. This improvement enhances the model’s stability and scalability, or its generality. Third, our contrastive learning strategy mitigates the instability issues resulting from sparse data. To validate our model, we conducted multiple sets of experiments on commonly used datasets, demonstrating the model’s robustness and stability. Simultaneously, we amalgamate various datasets into a single, unified dataset. The experimental outcomes from this combined dataset substantiate the model’s robust adaptability. Conclusions Our research findings affirm that the StableDNAm model is a general, stable, and effective instrument for DNA methylation prediction. It holds substantial promise for providing invaluable assistance in future methylation-related research and analyses. | StableDNAm: towards a stable and efficient model for predicting DNA methylation based on adaptive feature correction learning | 10.1186/s12864-023-09802-7 |
2023-12-04 | The potential effects of microplastic particle exposure on environmental organisms has sparked intense research activities. Various studies have been conducted, however on a limited set of mostly pristine polymer materials. In parallel to the ongoing research activities, it is discussed to include non-natural polymers into the registration process under REACH. Currently, non-natural polymers are exempted from registration, based on the general assumption of being non-hazardous due to their high molecular weight. In addition, the extensive number of polymers exceeding the registration capacities was mentioned as a reason for exemption. Hence, relevant polymers requiring a registration shall be selected according to specific criteria that help to identify those with a concern for hazardous effects. In the line of these developments we here present the results of a systematic ecotoxicity testing of 16 microplastic particles of different polymer composition, part of which are micronized polymer powders used in 3D printing (intentionally produced primary microplastic, losing particle shape by the 3D printing). All polymer materials were systematically varied and extensively characterised with regard to their properties (e.g. particle size, cross-linking, molar mass distribution, end groups, reactivity). Most of the polymers exerted toxicity in 48 h acute Daphnia magna immobilisation assay and 72 h chronic Raphidocelis subcapitata growth inhibition assay, except one PA and one HDPE material showing toxicity in D. magna , and one HDPE material showing toxicity in green algae. From these results we conclude that none of the microplastic particles studied here, independent of their polymer properties, give raise to concern for hazardous effects. | Polymers of low concern? Assessment of microplastic particles used in 3D printing regarding their toxicity on Raphidocelis subcapitata and Daphnia magna | 10.1186/s43591-023-00078-y |
2023-12-04 | Background Insomnia disorder (ID) seriously affects people’s daily life. Difficulty falling asleep is the most commonly reported complaint in patients with ID. However, the mechanism of prolonged sleep latency (SL) is still obscure. The aim of our present study was to investigate the relationship between prolonged SL and alterations in spontaneous neural activity and brain functional connectivity (FC) in ID patients using functional magnetic resonance imaging (fMRI). Methods A total of 52 insomniacs with difficulty falling asleep and 30 matched healthy controls (HCs) underwent resting-state fMRI. The amplitude of low-frequency fluctuation (ALFF) was measured and group differences were compared. The peak areas with significantly different ALFF values were identified as the seed regions to calculate FC to the whole brain. SL was assessed by a wrist actigraphy device in ID patients. The Pittsburgh Sleep Quality Index (PSQI), Hamilton Anxiety Rating Scale (HAMA), and Hyperarousal Scale (HAS) were evaluated in both ID patients and HCs. Finally, correlation analyses were performed between the clinical features and FC/ALFF values. Results ID patients showed higher PSQI, HAMA, HAS scores than HCs. The functional MRI results indicated increased ALFF value in the left insula and right amygdala and decreased ALFF value in the right superior parietal lobe (SPL) in ID patients. The seed-based FC analysis demonstrated increased FC between the left insula and the bilateral precentral gyrus and FC between the right amygdala and the left posterior cingulate cortex (PCC) in patients with ID. Correlation analysis indicated that the increased FC value of the right amygdala-left PCC was positively correlated with SL measured by actigraphy. Conclusion This study revealed abnormal regional spontaneous fluctuations in the right amygdala, left insula, and right SPL, as well as increased FC in the left insula-precentral and right amygdala-left PCC. Moreover, the prolonged SL was positively correlated with the abnormal FC in the right amygdala-left PCC in ID patients. The current study showed the correlation between prolonged SL and the abnormal function of emotion-related brain regions in ID patients, which may contribute to a better understanding of the neural mechanisms underlying difficulty falling asleep in patients with ID. Clinical Trial Registration http://www.chictr.org.cn ., ChiCTR1800015282. Registered on 20th March 2018. | Abnormal alterations of regional spontaneous neuronal activity and functional connectivity in insomnia patients with difficulty falling asleep: a resting-state fMRI study | 10.1186/s12883-023-03481-3 |
2023-12-04 | In organic solar cells (OSCs), it is an effective way to improve the power conversion efficiency (PCE) by adding a guest component with appropriate absorption and energy levels in the host system. Herein, a new nonfullerene acceptor (NFA) named TBF-2Cl was developed by the strategy of expanding the π conjugated core of 2,2′-(((4,4,9,9-tetrahexyl-4,9-dihydro-s-indaceno[1,2-b:5,6-b′]dithiophene-2,7-diyl)bis(methaneylylidene))bis(5,6-dichloro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IDT-4Cl) with two benzene rings. With increase of benzene units, TBF-2Cl exhibits higher lowest unoccupied molecular orbital (LUMO) level of −3.75 eV than that of one benzene unit based NFA IDT-4Cl and fluorene core based NFA F-2Cl, which facilitates enhancing the open-circuit voltage ( V oc ) of ternary devices. Moreover, TBF-2Cl film shows a medium optical bandgap with the absorption range from 500–800 nm, being well complementary with the wide bandgap polymer donor D18 and narrow bandgap NFA CH-6F. Accordingly, a remarkable PCE of 18.92% with a high short-circuit current density ( J sc ) of 27.40 mA·cm −2 , a fill factor (FF) of 0.749, especially an outstanding V oc of 0.922 V was achieved for the optimal ternary device based on D18:TBF-2Cl:CH-6F, surpassing the binary counterpart (17.08%). The findings provide insight into the development of new guest acceptors for obtaining more efficient OSCs. | A new nonfullerene acceptor with an extended π conjugation core enables ternary organic solar cells approaching 19% efficiency | 10.1007/s12274-023-6293-7 |
2023-12-04 | Objective To analyse the efficacy of the therapeutic use of low-level laser therapy (LLLT) on the tissue repair process of allogeneic scleral grafts in patients with contracted sockets by analysing the speed of graft vascularisation and fornice depth of contraction percentage. Methods A retrospective chart review was performed from April 2015 to April 2021 including 39patients with socket contraction. Allogeneic scleral grafts were used to repair the sockets in all patients. They were randomly enrolled into two groups. The laser group included 18 patients treated with LLLT after the surgery, whereas the control group included 21 patients without LLLT after the surgery who healed naturally. The LLLT equipment used in the research had a wavelength of 650 nm, 10 mW power, and 3.8 J/cm 2 dosimetry, and the procedure was performed once daily for 5 min over 7 days, beginning 1 week postoperatively. All patients were followed up over 6 months to examine the changes in the size of the area of the non-vascularised graft and upper and inferior fornice depth. Results The laser group presented a significantly increased speed of conjunctival vascularisation compared with the control group ( P = 0.003). The fornice depth of contraction percentage was more apparent in the control group than that in the laser group ( P = 0.000). Conclusion LLLT accelerates conjunctival vascularisation, stimulates conjunctival incision healing within a short period, shortens the tissue repair process, reduces the local inflammatory response, and causes no significant shrinkage of the conjunctival sac. | Low-level laser therapy combined with scleral graft transplantation in the treatment of contracted socket: a clinical study | 10.1186/s12886-023-03242-3 |
2023-12-03 | In an era defined by energy security, healthcare advancements, and the pursuit of clean energy solutions, nuclear energy emerges as a potent candidate. However, a major bottleneck in its growth is the hindrance posed by the extrapolation of risk due to high-dose radiation to the low-dose region (< 100 mSv), according to the linear no-threshold (LNT) model. This creates undue radiophobia among the members of public leading to resistance against the applications of radiation for societal uses. This perspective article proposes a quantum approach to augment a hormesis or threshold model as an alternative to the LNT model while also discussing the LNT’s fallacies. To provide a more fundamental explanation to the several nonlinear biological processes underpinning such alternative models, this article suggests a quantum biology approach. Drawing inspiration from celebrated quantum biology examples across photosynthesis, magnetoreception and olfaction, this article discusses ways in which nontrivial quantum phenomena can explain nonlinear low doses processes such as upregulation of reactive oxygen species, DNA repair mechanisms, and other adaptive responses. By presenting quantum biology as a fundamental basis for nonlinearity, this article tries to underscore the potential of scientifically driven hormesis/threshold model to challenge the LNT model and maximize the numerous peaceful societal applications of nuclear energy. | Need of Quantum Biology to Investigate Beneficial Effects at Low Doses (< 100 mSv) and Maximize Peaceful Applications of Nuclear Energy | 10.1007/s12647-023-00710-5 |
2023-12-01 | Fused filament fabrication (FFF) is one of the additive manufacturing (AM) techniques that have revolutionized the manufacturing strategy in the last 2 to 3 decades. The quality of the parts prepared by the FFF process is dependent upon the static and variable process parameters. It has been reported by previous studies that part shrinkage, part shrinkage, high surface roughness, warping from the edges, misaligned part geometry, lack and loss of the adhesion, part distortion, voids and porosity etc., are the major issues in the fused filament fabrication process. In the case of open-source fused filament fabrication, internal and external factors such as; the variable room temperatures, room humidity, wind speed, heterogeneity in feedstock materials, torsion in feedstock filaments, vibration due to any source, nozzle clogging, nozzle choking, high/low nozzle and bed temperature are conducive for the mentioned issues. The present study is the state of review for minimizing defects in the final product by suggesting the methods and procedure for each issue in the FFF process. This study would be helpful for novice researchers who are working on different applications of the FFF process. In this review work, most common defects and problems observed during 3D printing are elaborated and discussed according to literature review and also solution of defects has been discussed. | Fused filament fabrication: A state-of-the-art review of the technology, materials, properties and defects | 10.1007/s12008-022-01026-5 |
2023-12-01 | Abstract High speed impact at strain rates > 10 3 s −1 has generic characteristics in context of energy absorption and adiabatic temperature rise. An ultra-high strength low alloy steel (USLA, 3.8 mm thick) subjected to high-speed impact has been investigated by focusing on energy absorption driven by thermo-kinetics phenomenon in correlation with the target plate thickness. Result was bulge and reduction in thickness up to 2 mm at impact point. An analytical model has been proposed by establishing a relation between absorbed energy and plate thickness to explain deformation characteristics. EBSD analysis was carried out at three specified points, i.e., impact zone (IZ), impact affected zones (IAZ; through-thickness direction near backside) and (IAZ; radial/circumferential direction) with in 3 mm diameter. Impact analysis was carried out in Ls Dyna computer code. EBSD and FE (finite element) analysis revealed that the shear wave velocity under the influence of adiabatic temperature rise up to 520 K has generated adiabatic shear bands in IZ and IAZ (through-thickness direction), however in the IAZ (radial direction), the plate experienced no adiabatic temperature and increased stress due to compressive wave velocity resulted in greater proportion of recrystallized grain structure which is 25.79% as compared to 10.98% in IAZ(through-thickness direction) and 6.19% in IZ (impact zone). Micro hardness testing of these three distinct zones also revealed that IAZ (radial direction) has higher hardness (630HV) than IZ (600HV) and IAZ (through-thickness direction) (570HV) owing to increased and evenly distributed fine-grained microstructure in IAZ (radial direction), and relatively less deformation damage. Graphical Abstract | Synergistic Effect of Energy Absorption and Adiabatic Temperature on the Microstructural Evolution and Mechanical Properties During High-Speed Impacts | 10.1007/s12540-023-01466-y |
2023-12-01 | Delamination and burr in the small holes machining on carbon fiber reinforced polymer (CFRP) material workpieces remain a challenging research topic. In this research, low temperature assisted helical milling process is selected for small hole fabrications on CFRP. By analyzing the effects of critical process parameters (spindle speed n , axial feed per tooth f za and pitch a p ) on the machining quality of small holes, the interaction laws of process parameters are identified. Then, the prediction models of cutting temperature and exit damage (burr, delamination) are constructed based on experimental studies. The process parameters are further analyzed to identify the optimal parameters combination. Finally, using the low temperature assisted helical milling process and optimized process parameters, the maximum cutting temperature T max is reduced by 22.6%, the maximum burr length L is reduced to 14.3%, and the delamination factor F d is reduced from 1.042 to 1.019. The study provides an effective method for achieving high efficiency and low damage small hole fabrications on CFRP material. | Low Temperature Assisted Small Hole Fabrications on Carbon Fiber Reinforced Polymer | 10.1007/s40997-023-00634-0 |
2023-12-01 | Solar-driven water desalination is growing quickly, typically using other renewable energy sources. However, its efficiency is heavily reliant on design and process parameters. The aim of this study is to experimentally investigate the impact of various design and process parameters on the performance of single slope solar still. Thus, a homemade solar still has been fabricated using acrylic sheet with a basin area of 0.25 × 0.25 m 2 to carry out the experiments in Vellore, India (latitude 12.9692° N and longitude 79.1559° E). Additionally, this solar still setup is investigated using different absorbing plates (copper plate and copper plate with black coating), various glass cover angles (15°, 30° and 45°) and changing the wind speed (3 m/s, 3.5 m/s and 4 m/s) with help of electric fan. Daily energy efficiency and productivity of water are compared for the same basin area with different design and process parameters. From the results, daily energy efficiency and water productivity are improved with the increase of glass cover angle and wind speed. It is found that the best combination is copper plate with black coating, glass cover angle of 45° and wind speed of 4 m/s. This exhibits 34.09% in daily energy efficiency and 2640 ml/m 2 in productivity of water. After the desalination process, the primary ions (Na + , K + , Mg 2+ , and Ca 2+ ) of seawater are significantly reduced and satisfy the requirement of WHO standards. Subsequentially, dye removal is effectively achieved in the proposed solar still. | Design and process parametric investigations on acrylic-based single slope solar still to enhance daily energy efficiency and productivity of water: an application to desalination and dye removal | 10.1007/s11356-023-30995-7 |
2023-12-01 | Abstract The elastic (Young’s modulus) and relaxation (amplitude-independent internal friction) properties of metallic V and its low-activated alloys (V–4Cr–4Ti, V–W–Cr, V–Ta–Cr–Zr) have been studied by dynamic mechanical spectroscopy in the low-frequency range (0.5–30.0 Hz) and in the temperature range of 25–400°C in their annealed states. The solid-solution concentrations and diffusion characteristics (diffusion activation energies) of the C, O, N interstitial atoms have been determined. The changes in the obtained characteristics in comparison with their values for the cold-deformed states of the investigated materials have been determined. | Effect of Thermomechanical Treatment Modes on the Concentration and Diffusion Characteristics of Interstitial Atoms (C, O, N) and Elastic (Young’s) Moduli in Vanadium and Vanadium Alloys (V–4Cr–4Ti, V–W–Cr, V–Ta–Cr–Zr) | 10.1134/S1063778823130057 |
2023-12-01 | Development of energy-efficient lubricants is a way to reduce energy consumption for transportation, with the tendency to design molecules that are beneficial in reducing the viscosity of synthetic oils. Oligoether esters (OEEs), as a low-viscosity ester base oil, have characteristics such as simple synthesis and excellent lubrication effect, however, the application of OEEs in tribology field has rarely been investigated. The objective of the present study is to investigate the effect of structure on the lubricating performance of OEEs and to develop a predictive model for OEEs based on quantitative structure-property relationship (QSPR) through a combination of experiment and statistical modeling. Results showed that glycol chains contribute positively to lubrication with the ether functional groups increasing the sites of adsorption. Compared to branched-chain OEEs, straight-chain OEEs exhibited reduced wear, which was mainly due to the thicker adsorption film formed by the straight-chain structure. Furthermore, carbon films were detected on lightly worn surfaces, indicating that OEEs underwent oxidation during the friction process. Based on the results of principal component analysis (PCA) and partial least squares (PLS), it could be found that the predictive models of viscosity–temperature performance, thermal stability performance, coefficient of friction (COF), and wear volume (WV) performed well and robustly. Among them, COF and WV can be best predicted with an R 2 of about 0.90. | Low-viscosity oligoether esters (OEEs) as high-efficiency lubricating oils: Insight on their structure–lubricity relationship | 10.1007/s40544-023-0765-3 |
2023-12-01 | Comprehensive control of greenhouse gas emissions and response to climate change are concerns of countries around the world to protect living homes. The steel industry is responsible for over 10% of global CO 2 emissions, with approximately 80% of these emissions coming from the ironmaking process. Great efforts have been made in both blast furnace (BF) and non-blast furnace ironmaking processes to reduce emissions. Fluidized bed technology has become a crucial method used to process iron ore powder in non-blast furnace ironmaking, such as smelting reduction and direct reduction. This paper introduces the working principle and several typical working states of fluidized bed (FB) technology to clarify the key to fluidized bed process operation. And different kinds of fluidized bed ironmaking processes in recent decades are compared, including FIOR, DIOS, Circored, Circofer, FINMET, HIsmelt, FINEX, etc. Finally, the possible problems and solutions in the future development of fluidized bed ironmaking are analyzed. Hope that this work can contribute to the advancement of basic theory and technology research in fluidized bed reduction, and provide support for hydrogen metallurgy in the steel industry. Graphical Abstract | Development and Problems of Fluidized Bed Ironmaking Process: An Overview | 10.1007/s40831-023-00746-6 |
2023-12-01 | Spent carbon cathode (SCC) is a hazardous waste from the aluminum electrolysis industry. It is commonly used as a carbon source in the current disposal and recovery strategies, such as combustion, or as a reductant for smelting. The novelty of this study is to propose a strategy for recycling SCC as a graphite resource and to investigate the unique structural characteristics and adsorption properties of graphene oxide produced from this low temperature graphitized carbon. The adsorption kinetics and isotherms of SCC-GO on methylene blue (MB) were studied and compared with the GO prepared from natural flake graphite (NFG) and artificial graphite (AG). The results show that SCC-GO exhibits the highest adsorption rate and adsorption capacity (647.83 mg/g) for MB, which is much higher than NFG-GO (451.22 mg/g) and AG-GO (533.12 mg/g). The analysis of the spectroscopy and morphology confirmed that SCC-GO has a high degree of crystal defects, oxidation, and surface wrinkle. Overall, this study reveals the unique structure of SCC-GO and highlights its significant scientific and application potential as an ultra-low temperature graphitized carbon. This research is also significant for recycling aluminum electrolytic cathode solid waste in the form of a graphite source. | Structure characteristics and adsorption performance of graphene oxide prepared by spent carbon cathode—an ultra-low temperature graphitized carbon material | 10.1007/s11356-023-30884-z |
2023-12-01 | In this paper, the influence of different cooling processes on the stress, strain and shape warping of low carbon bainite steel Q690D during laminar cooling is analyzed, and a temperature stress–strain coupled finite element model of low carbon bainite steel Q690D is established. For the warping deformation of medium and thick plates, edge shielding, symmetrical cooling of upper and lower surfaces and head shielding are adopted for their length, width and thickness. The results show that when using edge occlusion, the best occlusion distance is 0.1 m; when the upper and lower surfaces are symmetrically cooled, the stress symmetry is basically realized; when head shielding is used, the best masking distance is 0.2 m. | Variation of Plate Shape in Laminar Cooling Process of Low Carbon Bainitic Steel Q690D | 10.1007/s11665-023-07885-7 |
2023-12-01 | A new methodology was used to determine the speed of sound in water by using low frequency ultrasound over the temperature range 20 to 95° C. The initial procedure was developed based on finding the resonant locations over variable pathlengths in an acoustic tube and calculating their separation distances through the water, yielding the wavelength (λ) measurement. An in-house gain detector was employed to detect the resonant points, through detection of the amplitude voltage peaks in response to the displacement of the moving transmitter. The λ was calculated as 53 mm for water at 20° C with the fixed frequency of 28 kHz. As a result, using the universal wave equation, the speed of sound was estimated to be 1484 m/s with an accuracy of 99.89% compared to the references. The methodology was then followed through the second procedure to measure the sound speeds at temperatures higher than 20 °C, using coincidence frequency determination over different temperatures. In a fixed acoustic pathlength equal to the calculated λ at 20° C, the initial frequency, 28 kHz, was linearly swept to track the coincidence frequency corresponding to certain temperatures. The gain detector was used to obtain the coincidence frequencies, wherein the amplitude voltage peaks were recorded during the frequency adjustment. The simultaneous monitoring with an oscilloscope consolidated data when the phase differences between radiated and received waves were eliminated at the coincidence frequencies. The measured coincidence frequencies were then directly used to determine the speed of sound in water as function of temperature. The third order curve fitted to the results yielded an R 2 equal to 0.9856, representing excellent agreement with the reference data. | A New Method in Applying the Universal Wave Equation to Measure the Speed of Sound in Water as a Function of Temperature with Low Frequency Ultrasound | 10.1007/s40799-023-00627-3 |
2023-12-01 | Purpose of Review Advances in zirconia ceramics have expanded their application in dentistry, necessitating faster delivery of zirconia-based restorations. With the introduction of high translucency grades of zirconia ceramics, the rapid sintering strategies that aim to reduce processing times can have a central impact on clinically relevant properties. The present review has surveyed the available literature evaluating the properties of rapidly sintered dental zirconia ceramics. Recent Findings Recent studies emphasize the evolution of sintering protocols for zirconia ceramics, especially highlighting differences between conventional sintering (CS) and rapid methods like speed (SS) and high-speed sintering (HSS). These modern rapid sintering techniques transform the microstructure of zirconia ceramics, impacting its translucency, flexural strength, and aging resistance. These properties exhibit variability based on zirconia type and chosen sintering process, with HSS showing particular promise. Summary Rapid sintering protocols offer efficient alternatives to traditional zirconia ceramic processing, with benefits in cost and time. Despite the recent findings, discrepancies persist within zirconia generations, calling for further standardization and investigation. | Sintering Strategies for Dental Zirconia Ceramics: Slow Versus Rapid? | 10.1007/s40496-023-00355-y |
2023-12-01 | Advanced electromagnetic interference (EMI) shielding materials with high EMI shielding efficiency (SE) and low reflection have significant potential for reducing the secondary electromagnetic radiation contamination. In this study, a gradient-conductive Ag/BaFe 12 O 19 microfiber/polyimide (GCABP) composite film with exceptional EMI SE is fabricated by blow spinning. The gradient-conductive structure effectively minimizes electromagnetic wave reflection. The incorporation of BaFe 12 O 19 microfiber further enhances the EMI SE of the film. At a thickness of 100 µm, the EMI SE of the composite film can reach 98.9 dB with an absorption coefficient of 0.75, confirming the GCABP film as an absorbing EMI shielding material. The polyimide safeguards the Ag microfiber and BaFe 12 O 19 microfiber, ensuring the stability of the GCABP film in extreme environments. Additionally, the GCABP film exhibits exceptional thermal management performance, such as achieving a high surface temperature of 315°C at a low supply voltage of 1.4 V, rapid response time of 5.4 s, reliable cyclic heating stability, and good overall reliability. Given its outstanding comprehensive properties, the GCABP film holds significant potential for diverse applications in the national defense industry and aerospace sector. 高屏蔽效率和低反射特性的先进电磁干扰屏蔽(EMI SE)材料在降 低二次电磁辐射污染方面具有巨大的潜力. 本研究采用气流纺丝法制备了 具有优异EMI SE的梯度导电Ag/BaFe12O19超细纤维/聚酰亚胺(GCABP)复合 薄膜. 梯度导电结构有效地减少了电磁波的反射. BaFe12O19微纤维的掺入 进一步提高了薄膜的EMI SE. 在厚度为100 µm时, 复合膜的EMI SE可达 98.9 dB, 吸收系数(A)为0.75, 证实了GCABP膜是一种吸波型EMI屏蔽材料. 聚酰亚胺(PI)保护Ag超细纤维和BaFe12O19超细纤维, 确保GCABP薄膜在极 端环境下的稳定性. 此外, GCABP薄膜表现出优异的热管理性能, 如其在 1.4 V的低电压下表面温度高达315°C, 响应时间达到5.4 s, 循环加热能力稳 定, 整体可靠性好. 鉴于其出色的综合性能, GCABP薄膜在国防工业和航空 航天等领域具有巨大的应用潜力. | Flexible Ag/BaFe12O19 microfiber/polyimide composite film with high electromagnetic interference shielding and low reflection | 10.1007/s40843-023-2650-8 |
2023-12-01 | Corpus Christi Bay is a shallow, wind-driven lagoon located on the semi-arid South Texas coast that has a rapidly urbanizing watershed. Projections indicate that this region will become warmer and drier and will support an increasing urban population over the next several decades. Here, a 27-month field study was undertaken to quantify phytoplankton biovolume, community composition, and relationships with environmental drivers. Phytoplankton biovolume varied unimodally with a peak in biovolume from spring through summer followed by a decline into fall and winter. Phytoplankton growth was related to nutrient availability during the spring and summer, while water temperature and factors affecting flushing were important during the fall and winter. Regions with more restricted circulation patterns (i.e., man-made canals) were found to support higher standing crops of phytoplankton and the occurrence of high biovolume blooms. Diatoms were dominant during the winter and spring, dinoflagellates were dominant during the summer and fall, and picophytoplankton groups were important during spring, summer, and fall. These results suggest that nutrient and physical conditions interact to determine phytoplankton biomass and community composition and contribute to our ability to project potential impacts of future increases in human populations in the watershed, decreasing precipitation due to climate change, and increasing frequency of short-lived flood events. | Variability in Phytoplankton Biomass and Community Composition in Corpus Christi Bay, Texas | 10.1007/s12237-022-01137-y |
2023-12-01 | The elastic modulus of titanium is greatly influenced by the stability of the β -phase. Metastable β or near- β titanium with low β -phase stability and non-toxic elements can often achieve a lower elastic modulus. This study proposed a high efficiency composition design method combining CALPHAD calculations and nanoindentation test to design the Ti-Nb-Zr-Sn-Ta alloy with low modulus. By this method, a near- β titanium Ti-18Nb-8Zr-5Sn-2Ta with low-modulus, high-strength and good plasticity (elastic modulus (58.3±2.0) GPa, tensile strength (813.3±7.2) MPa, elongation (25.3±2.1)%) was developed. The experimental results showed that conventional molybdenum equivalent method overestimates the β -stability of Sn and Zr on titanium alloys, and Nb and Ta are more effective β -stabilizers for Ti-Nb-Zr-Sn-Ta alloy. 钛的弹性模量受 β 相稳定性的影响较大。具有低 β 相稳定性和无毒元素的亚稳定 β 或近 β 钛通常可以实现较低的弹性模量。本研究提出了一种高效的组成设计方法,结合CALPHAD计算和纳米压痕测试,以设计具有低模量的Ti-Nb-Zr-Sn-Ta 合金。通过这种方法,开发了一种具有低模量、高强度和良好塑性(弹性模量为(58.3±2.0) GPa,抗拉强度为(813.3±7.2) MPa,伸长率为(25.3±2.1)%)的近 β 钛Ti-18Nb-8Zr-5Sn-2Ta。实验结果显示,传统的钼当量法高估了Sn 和Zr 对钛合金的 β 相稳定性的影响,而对于Ti-Nb-Zr-Sn-Ta合金,Nb和Ta能更有效地稳定 β 相。 | Integration of CALPHAD calculations and nanoindentation test for the design of low-modulus near-β titanium | 10.1007/s11771-023-5515-1 |
2023-12-01 | Very high gravity (VHG) ethanol fermentation at low temperatures can be a way to obtain wines with high ethanol content (> 15 °GL). The production of vinasse is lower, compared to typical industrial conditions, which reduces the costs of storage and transport. However, there is greater heat generation during cell growth, resulting in an increased requirement for cooling water. One promising way to cool the vat is to use CO 2 stripping, which removes heat by vaporization of the ethanol and water in the broth. Therefore, the aim of the present study was to find suitable operating conditions, considering the gas flow rate ( $${F}_{{\mathrm{CO}}_{2}}$$ F CO 2 ) and the stripping start ( $${t}_{\mathrm{start}}$$ t start ) and stop ( $${t}_{\mathrm{stop}}$$ t stop ) times, that could reduce the volume of water required for temperature control. Simulations of extractive fermentations at 28 and 34 °C, with must substrate concentration ( $${C}_{\mathrm{SM}}$$ C SM ) of 300 g/L, were performed to obtain $${F}_{{\mathrm{CO}}_{2}}$$ F CO 2 , $${t}_{\mathrm{start}}$$ t start , and $${t}_{\mathrm{stop}}$$ t stop . Experimental validations showed water volume reductions of 66.4% (28 °C) and 67.0% (34 °C), compared to the corresponding conventional ethanol fermentations. An extractive VHG fermentation at 28 °C, with $${C}_{\mathrm{SM}}$$ C SM =372 g/L, was carried out under the conditions obtained in the simulations. The results showed a 61.9% reduction in water volume and a total ethanol content of 15 °GL. The gas stripping technique applied to VHG fermentation at low temperature was proved to be environmentally friendly, since it reduced the volume of vinasse generated and saved water, which could reduce the number of heat exchangers and the costs associated with their maintenance. | Thermal Analysis of Conventional and Extractive Fed-Batch Ethanol Fermentation at Different Temperatures | 10.1007/s12155-023-10586-7 |
2023-12-01 | The present study focuses on comparative assessment of impact strength of self-healing Al6061 composite reinforced with shape memory alloy (SMA) and low melting point alloy. The self-healing Al6061 composites have been prepared by filling (i) low melting point alloy 60Pb40Sn and (ii) NiTi SMA in the Al6061 alloy. Experimental investigations have been carried out to assess the impact strengths of both of these self-healing Al6061 composites using Charpy impact test. The results show that the low melting point alloy filled self-healing Al6061 composite has lower absorbed energy as compared to SMA wire self-healing Al6061 composite. Simulation of the all three-sample performed on software to ensure the experimental results. Graphical Abstract | Impact strength assessment of SMA and low melting point alloy reinforced self-healing Al6061 composite | 10.1007/s12008-022-01039-0 |
2023-12-01 | Catalytic destruction of nitrogen oxides (NO x ) combined with dust removal technique has attracted much attention, yet the application in the solid waste incineration air pollution control process is still lacking due to the complex flue gas atmosphere. In this work, the Mn-Ce-Co-O x catalyst–coated polyphenylene sulfide (PPS) filter fiber with efficient dust removal and low-temperature polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) destruction has been prepared with a redox-precipitation method. The catalyst was uniformly grown around the PPS fiber with appropriate catalyst loading. The effects of several key operating parameters (e.g., reaction temperature, catalyst loading amount, and filtration velocity) on the catalytic efficiency were comprehensively investigated. The results show that the Mn-Ce-Co-O x /PPS has a decomposition yield of 78.0% in PCDD/Fs and 96% in nitric oxide (NO) conversion at 200 °C. The poisoned catalytic filter exhibits a removal efficiency of 88.6% for PCDD/Fs. In addition, the catalytic filter can completely reject particles smaller than 1.0 μm with a low filtration resistance. Therefore, this efficient and energy-conserving catalytic filter shows promising applications in flue gas pollution treatments. Graphical abstract | Low-temperature catalytic oxidation of PCDD/Fs over MnCeCoOx/PPS catalytic filter | 10.1007/s11356-023-30768-2 |
2023-12-01 | The crystallization, microstructure analysis, and sintering behavior, microwave properties of (Mg 0.95 Co 0.05 ) 2 (Ti 1− x Sn x )O 4 ceramics, processed with raw powders of MgO, CoO, SnO 2 , and TiO 2 via the conventional solid-state method are investigated. X-ray diffraction and X-ray spectroscopy analyses showed that the crystal structure of these samples was spinel-type. The microstructure with the substitution amount of Sn 4+ and the dielectric performances of the (Mg 0.95 Co 0.05 ) 2 (Ti 1− x Sn x )O 4 ceramics were also explored. The (Mg 0.95 Co 0.05 ) 2 (Ti 1− x Sn x )O 4 ceramic could be sintered at 1350 °C, and the microwave dielectric performance was found to be strongly correlated with the sintering temperature. A maximum quality factor ( Q × f ) value of 330,000 (GHz), dielectric constant (ε r ) of 14.75, and temperature coefficient (τ f ) of −47.5 ppm/°C were achieved for samples sintered at 1350 °C for 4 h. (Mg 0.95 Co 0.05 ) 2 (Ti 0.97 Sn 0.03 )O 4 material system shows high potential for applications of high frequency-selection components in satellite communication and 5th Generation Mobile Communication Technology wireless telecommunication systems. | Microstructure, crystallization, microwave properties of (Mg0.95Co0.05)2(Ti1−xSnx)O4 spinel-type solid solution for microwave applications | 10.1007/s41779-023-00879-7 |
2023-12-01 | The Member States of the European Union pledged to reduce greenhouse gas emissions by 80–95% by 2050. Shallow geothermal systems might substantially contribute by providing heating and cooling in a sustainable way through seasonally storing heat and cold in the shallow ground (<200 m). When the minimum yield associated with the installation of a cost-effective aquifer thermal energy storage (ATES) system cannot be met, borehole thermal energy storage, relying mostly on the thermal conductivity of the ground, is proposed. However, for large-scale applications, this requires the installation of hundreds of boreholes, which entails a large cost and high disturbance of the underground. In such cases, ATES systems can nevertheless become interesting. This paper presents a case study performed on a Ghent University campus (Belgium), where the feasibility of ATES in an area with a low transmissivity was determined. The maximum yield of the aquifer was estimated at 5 m 3 /h through pumping tests. Although this low yield was attributed to the fine grain size of the aquifer, membrane filtering index tests and long-term injection tests revealed that the clogging risk was limited. A groundwater model was used to optimize the well placement. It was shown that a well arrangement in a checkerboard pattern was most effective to optimize the hydraulic efficiency while maintaining the thermal recovery efficiency of the ATES system. Hence, for large-scale projects, efficient thermal energy storage can also be achieved using a (more cost-effective) ATES system even in low-permeability sediments. Les Etats Membres de l’Union Européenne se sont engagés à réduire leurs émissions de gaz à effet de serre de 80 à 95 % d’ici 2050. Les systèmes géothermiques peu profonds pourraient y contribuer de manière significative en fournissant du chauffage et du refroidissement de manière durable grâce au stockage saisonnier de la chaleur et du froid dans le sol peu profond (<200 m). Quand la production minimale, associée à l’installation d’un système rentable de stockage d’énergie thermique en aquifère (SETA), ne peut pas être atteinte, un stockage d’énergie thermique en forages, s’appuyant principalement sur la conductivité thermique du sol, est proposé. Cependant, pour des applications à grande échelle, ceci requiert l’installation de centaines de forages, ce qui engendre un coût élevé et une perturbation importante du sous-sol. Dans de pareils cas, les systèmes SETA peuvent cependant devenir intéressants. Cet article présente une étude de cas réalisée sur le campus de l’Université de Gand (Belgique) où la faisabilité d’un SETA dans une zone à faible transmissivité a été établie. La production maximale de l’aquifère a été estimée à 5 m 3 /h d’après les essais de pompage. Bien que cette faible production ait été attribuée à la granulométrie fine de l’aquifère, des essais sur l’indice de filtration membranaire et des tests d’injection de longue durée ont montré que le risque de colmatage était limité. Un modèle hydrogéologique a été utilisé pour optimiser l’emplacement des puits. Il a été démontré que le dispositif de puits en damier était le plus efficace pour optimiser l’efficacité hydraulique tout en maintenant l’efficacité de la récupération thermique du système de SETA. Ainsi, pour des projets à grande échelle, un stockage d’énergie thermique efficace peut aussi être atteint en réalisant un système de SETA (plus rentable), même dans des sédiments faiblement perméables. Los estados miembros de la Unión Europea se comprometieron a reducir las emisiones de gases de efecto invernadero en un 80–95% para 2050. Los sistemas geotérmicos poco profundos podrían contribuir sustancialmente proporcionando calefacción y refrigeración de forma sostenible mediante el almacenamiento estacional de calor y frío en el subsuelo poco profundo (<200 m). Cuando no puede alcanzarse el rendimiento mínimo asociado a la instalación de un sistema rentable de almacenamiento de energía térmica en acuíferos (ATES), se propone el almacenamiento de energía térmica en perforaciones, que se basa principalmente en la conductividad térmica del suelo. Sin embargo, para aplicaciones a gran escala, esto requiere la instalación de cientos de perforaciones, lo que conlleva un gran coste y una elevada perturbación del subsuelo. En tales casos, los sistemas ATES pueden resultar interesantes. Este artículo presenta un estudio de caso realizado en un campus de la Universidad de Gante (Bélgica), en el que se determinó la viabilidad de la ATES en una zona de baja transmisividad. El rendimiento máximo del acuífero se estimó en 5 m 3 /h mediante pruebas de bombeo. Aunque este bajo rendimiento se atribuyó al tamaño de grano fino del acuífero, las pruebas del índice de filtración de la membrana y las pruebas de inyección a largo plazo revelaron que el riesgo de obstrucción era limitado. Se utilizó un modelo de aguas subterráneas para optimizar la colocación de los pozos. Se demostró que la disposición de los pozos en forma de damero era la más eficaz para optimizar la eficiencia hidráulica y mantener al mismo tiempo la eficiencia de recuperación térmica del sistema ATES. Por lo tanto, para proyectos a gran escala, también se puede lograr un almacenamiento eficiente de energía térmica utilizando un sistema ATES (más rentable) incluso en sedimentos de baja permeabilidad. 欧盟成员国承诺到2050年将温室气体排放减少80–95%。浅层地热系统可以通过在浅地层（<200 m）中储存冷热的方式，在可持续的条件下提供供暖和制冷。当安装成本有效的地下储能地热系统（ATES）无法满足最低产量要求时，提议采用主要依赖地壳热导率的钻孔热能系统。然而，对于大规模应用，这需要安装数百个钻孔，这带来了较大的成本和对地下环境的严重干扰。在这种情况下，ATES系统仍然具有一定的吸引力。本文介绍了在比利时根特大学校园进行的一个案例研究，以确定在一个低导水系数区中采用ATES的可行性。通过抽水试验，估计了含水层的最大出水量为5 m 3 /h。尽管这种低出水量被归因于含水层的细颗粒大小，但膜过滤指数测试和长期注入试验表明堵塞风险是有限的。地下水模型被用于优化井的位置。结果显示，棋盘状的井布置方式在保持ATES系统热回收效率的同时，最有效地优化了水力效率。因此，对于大规模项目，即使在低渗透性沉积物中，也可以通过使用（更具成本效益的）ATES系统实现高效的热能储存。 Os Estados Membros da União Europeia comprometeram-se a reduzir as emissões de gases de efeito estufa em 80–95% até 2050. Os sistemas geotérmicos rasos podem contribuir substancialmente ao fornecer aquecimento e resfriamento de forma sustentável através do armazenamento sazonal de calor e temperaturas frias no solo raso (<200 m). Quando o rendimento aquífero mínimo associado à instalação de um sistema econômico de armazenamento aquífero de energia térmica (ATES) não pode ser alcançado, é proposto o armazenamento de energia térmica de poço, contando principalmente com a condutividade térmica do solo. No entanto, para aplicações de grande escala, isso requer a instalação de centenas de poços, o que acarreta um grande custo e alta perturbação do subsolo. Nesses casos, entretanto, os sistemas ATES podem se tornar interessantes. Este artigo apresenta um estudo de caso realizado no campus da Universidade de Ghent (Bélgica), onde foi determinada a viabilidade do ATES em uma área com baixa transmissividade. O rendimento máximo do aquífero foi estimado em 5 m 3 /h através de testes de bombeamento. Embora esse baixo rendimento tenha sido atribuído ao tamanho de grão fino do aquífero, índices de testes de filtragem por membrana e testes de injeção de longo prazo revelaram que o risco de obstrução era limitado. Um modelo de água subterrânea foi usado para otimizar a locação do poço. Foi demonstrado que um arranjo de poços em um padrão quadriculado foi o mais eficaz para otimizar a eficiência hidráulica, mantendo a eficiência de recuperação térmica do sistema ATES. Portanto, para projetos de grande escala, o armazenamento eficiente de energia térmica também pode ser alcançado usando um sistema ATES (mais econômico) mesmo em sedimentos de baixa permeabilidade. | Assessing the potential of low-transmissivity aquifers for aquifer thermal energy storage systems: a case study in Flanders (Belgium) | 10.1007/s10040-023-02696-5 |
2023-12-01 | Sweetpotato [ Ipomoea batatas (L.) Lam] is one of the most important crops for food, feed, industrial material, and bio-energy resource. However, since it originated in tropical regions, sweetpotato exhibits limited cold tolerance, hindering its cultivation in low-temperature areas. To comprehend the sweetpotato response to chilling stress, de novo transcriptome assembly was conducted on leaves from two sweetpotato cultivars: the cold-tolerant Liaohanshu 21 and the cold-sensitive Shenshu 28, exposed to low-temperature stress for 3 h and 24 h. 787.24 million raw reads and 763.44 million clean reads were obtained, 60.60–66.06% of clean reads successfully mapped to the reference database across all 18 libraries. 2524 unigenes were identified as transcript factors and classified into 55 families in Plant Transcription Factor Database (PlantTFDB) and 4671 unigenes were matched to 24 groups in Plant Resistance Gene Database (PRGdb). In Liaohanshu 21, 3618 genes and 8391 genes exhibited significant differential expression 3 h and 24 h of low-temperature exposure, respectively. In Shenshu 28, 13,394 genes and 11,627 genes displayed substantial differential expression after 3 h and 24 h of low-temperature exposure, respectively. The differentially expressed genes (DEGs) were further analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genome (KEGG) database. DEGs related to “active oxygen scavenging systems”, “ lipid metabolism ”, and “ plant hormone signal transduction ” were potentially associated with sweetpotato’s cold resistance. This research offers insights into the mechanisms and genes involved in cold stress in sweetpotato’s response to cold stress and will contribute valuable information for cold-tolerant breeding of sweetpotato. | De novo transcriptome sequencing and gene expression profiling of sweetpotato leaves during low temperature stress | 10.1007/s11816-023-00851-8 |
2023-12-01 | This study evaluated the effect of potassium ferrate (PF) and low-temperature thermal hydrolysis co-pretreatment on the promotion of sludge hydrolysis process and the impact on acid production in the subsequent anaerobic digestion process. The analytical investigations showed that co-pretreatment significantly facilitated the hydrolysis process of the sludge and contributed to the accumulation of short-chain fatty acids (SCFAs). The pretreatment conditions under the optimal leaching of organic matter from sludge were hydrothermal temperature of 75°C, hydrothermal treatment time of 12 h, and PF dosage of 0.25 g g −1 TSS (total suspended solids), according to the results of orthogonal experiments. By pretreatment under proper conditions, the removal rate of soluble chemical oxygen demand (SCOD) achieved 71.8% at the end of fermentation and the removal rate of total phosphorus (TP) was 69.1%. The maximum yield of SCFAs was 750.3 mg L −1 , 7.45 times greater than that of the blank group. Based on the analysis of the anaerobic digestion mechanism, it was indicated that the co-pretreatment could destroy the floc structure on the sludge surface and improve organic matter dissolving, resulting in more soluble organic substances for the acidification process. Furthermore, microbial community research revealed that the main cause of enhanced SCFAs generation was an increase in acidogenic bacteria and a reduction of methanogenic bacteria. | Effects of Potassium Ferrate and Low-Temperature Thermal Hydrolysis Co-Pretreatment on the Hydrolysis and Anaerobic Digestion Process of Waste Activated Sludge | 10.1007/s11802-023-5512-x |
2023-12-01 | Polynyas, or ice-free regions within the sea ice pack, are a common occurrence around Antarctica. A recurrent and often large polynya is the Terra Nova Bay Polynya (TNBP), located on the western side of the Ross Sea just off Victoria Land. In this study, we investigate the atmospheric conditions leading to the occurrence of the TNBP and its spatial variability, as estimated using satellite-derived ice surface temperature and sea ice concentration data. A cluster analysis revealed that katabatic winds descending the Transantarctic Mountains, account for about 45% of the days when the TNBP exceeded its 2010–2017 mean extent plus one standard deviation. Warmer and more moist air intrusions from lower-latitudes from the Pacific Ocean, which are favoured in the negative phase of the Southern Annular Mode, play a role in its expansion in the remaining days. This is more frequent in the transition seasons, when such events are more likely to reach Antarctica and contribute to the occurrence and the widening of the polynya. In-situ weather data confirmed the effects of the mid-latitude air intrusions, while sea ice drifts of up to 25 km day −1 cleared the ice offshore and promoted the widening of the polynya starting from the coastal areas. Knowing the atmospheric factors involved in the occurrence of coastal polynyas around Antarctica is essential as it helps in improving their representation and predictability in climate models and hence advance the models’ capabilities in projecting Antarctic sea ice variability. | Atmospheric controls on the Terra Nova Bay polynya occurrence in Antarctica | 10.1007/s00382-023-06845-0 |
2023-12-01 | To study the applicability of biodiesel in marine engines, this research investigated the performance, combustion characteristics, and emission characteristics of biodiesel (B100), diesel, and a 50% volume blend of the two fuels (B50) in a marine engine. This study was conducted on a 4-cylinder, 520 mm-bore, two-stroke, low-speed marine engine with a common rail fuel and exhaust gas charge system. The three fuels were tested at different loads from 25%–100% with a step size of 25%. Results showed that the fuel consumption of pure biodiesel increased by about 13.5% and 3.8% relative to that of diesel at 25% and 100% loads, respectively, and by about 6% at 50% and 75% loads. In-cylinder combustion pressure was slightly reduced when the engine ran on biofuel, and black carbon emissions from biodiesel were reduced by an average of 54.7%. Compared with those from diesel, the carbon CO and total hydrocarbon emissions from B100 were reduced by 11.3% and 39%, respectively. Nitroxide emissions were elevated for B100 and B50 under all loading conditions. The properties of B50 blended diesel lie between those of B100 and diesel. In terms of combustion characteristics and emissions, biodiesel can be used without changing the engine parameters and can effectively reduce pollution, such as black carbon and carbon monoxide. | Combustion Analysis of Low-Speed Marine Engine Fueled with Biofuel | 10.1007/s11804-023-00375-1 |
2023-12-01 | Fibre reinforced geopolymer concrete holds the hybrid advantages of technical benefits and eco-friendliness. In this paper, an attempt was made to study the effect of glass fiber in an optimized geopolymer mix where the optimization was based on the dosage of slag replacement with fly ash as main precursor and different variations of the ratio of hydroxide to silicate since glass fibres proved to enhance the properties of cement-based composites, as per the literatures. The fresh and hardened properties of geopolymer mixtures, such as fluidity, setting time, water absorption, sorptivity, and mechanical properties (under ambient and heat curing temperatures) were considered for optimization process. The results revealed that there is a strong correlation noticed between physical and mechanical properties of the geopolymer samples and the chemical compositions of the binders and activator ratios. It was identified from the initial optimization process that 50% replacement of slag with fly ash along with 1.5 ratio of hydroxide to silicate oven cured composite (M11 mix) produced the maximum compressive strength of 33.59 MPa. M11 mix also produced enhanced tensile and flexural parameters with good resistance to free water and capillary water rise. The internal microstructure also showed denser nature and less micro cracks and flaws, thus considered as the optimized mix. Various dosages of glass fibres were then added to the optimized mix, say 0.5, 1, 1.5 and 2% which further revealed that 1% addition of glass fibre was efficient in all the mechanical, durability and microstructural aspects. | Influence of slag content and glass fibers on microstructure, durability and mechanical properties of geopolymer composites | 10.1007/s42107-023-00682-6 |
2023-12-01 | Abstract The main representatives of low-molecular-weight fluoropolymers obtained by the thermogasdynamic method of polytetrafluoroethylene (PTFE) pyrolysis, radiation polymerization of tetrafluoroethylene (TFE) in various solvents, and direct fluorination of low-molecular-weight paraffins are characterized. The features of the morphology, structure, molecular chain length, and thermal properties of the polymers obtained by various methods are shown. During repeated heat treatment of low-molecular weight fluoropolymers (heating to a temperature when the process of weight loss ends), regardless of the method of obtaining the polymer, new more dispersed low-molecular-weight fluoropolymers are formed, which may not differ from the original ones (fluoroparaffins) or differ in a number of characteristics (telomers, UPTFE (PTFE converted into low-molecular ultrafine powder) fractions). A new low-molecular-weight product is formed during the pyrolytic processing of high-molecular-weight copolymers of ethylene with TFE. The product is a low-molecular-weight form of ETFE, differing from the original objects in morphology, molecular chain length, and thermal properties. | Low-Molecular Fluoropolymers: Structure and Thermal Properties | 10.1134/S1990793123060039 |
2023-12-01 | Abstract Co–Ni supported catalysts were prepared by low-temperature combustion of dried mixture of solutions of cobalt and nickel nitrates and urea after impregnation of silica fabric (>97% SiO 2 ) premodified with 5, 10, and 15 wt % Al 2 O 3 . Modification of support was carried out by low-temperature combustion of dried mixture of solutions of aluminum nitrate and urea. Prepared supports and related catalysts were characterized by XRD, SEM, EDS, and BET method. The unreduced catalysts were found to contain oxides and complex oxides of nickel and cobalt. Reduction of catalysts with hydrogen at 400°C for 1 h was shown to contribute to forming metallic phases of Co and Ni; however, the nickel phase was detected only in reduced catalyst on unmodified fabric. The catalytic activity of catalysts was determined in the temperature range of 150–400°С. It was found that the reduced catalyst on support modified with 5 wt % Al 2 O 3 possesses the highest CO 2 conversion (61.8%) and methane yield (3.61 vol %) at 400°С. | Hydrogenation of CO2 on Co–Ni Catalysts Produced by Low-Temperature Combustion Using Modified Silica Fabric | 10.3103/S1061386223040131 |
2023-12-01 | This paper describes the synthesis of methacrylate-based terpolymer additives for diesel and biodiesel fuel that improve its properties at low temperatures. The synthesized additives contained different amounts of short-chain (methyl and benzyl) and long-chain (dodecyl and octadecyl) methacrylate comonomers. The crystallization behaviour of the additives and the formulations with diesel and biodiesel was observed by differential scanning calorimetry (DSC) and optical microscopy with polarization. DSC showed that the additives had a different effect on the crystallization temperature of the formulations. Microscopic images showed that the presence of additives influenced the size and number of wax crystals at low temperatures. Standard ASTM D5950 tests for pour point (PP) showed a large improvement in formulations with additives. In formulations with diesel, the addition of additives improved the PP value of diesel from − 18 °C to − 45 °C and in B10 diesel/biodiesel formulations from − 18 °C to − 54 °C. | Methacrylate terpolymers with short-chain comonomers as pour point depressants for diesel fuel and blends with biodiesel | 10.1007/s10973-023-12633-z |
2023-12-01 | Cement, phosphorous slag (PS), and steel slag (SS) were used to prepare low-carbon cementitious materials, and triisopropanolamine (TIPA) was used to improve the mechanical properties by controlling the hydration process. The experimental results show that, by using 0.06% TIPA, the compressive strength of cement containing 60% PS or 60% SS could be enhanced by 12% or 18% at 28 d. The presence of TIPA significantly affected the hydration process of PS and SS in cement. In the early stage, TIPA accelerated the dissolution of Al in PS, and the formation of carboaluminate hydrate was facilitated, which could induce the hydration; TIPA promoted the dissolution of Fe in SS, and the formation of Fe-monocarbonate, which was precipitated on the surface of SS, resulting in the postponement of hydration, especially for the high SS content. In the later stage, under the continuous solubilization effect of TIPA, the hydration of PS and SS could refine the pore structure. It was noted that compared with portland cement, the carbon emissions of cement-PS-TIPA and cement-SS-TIPA was reduced by 52% and 49%, respectively. | Research on the Low-carbon Cementitious Materials: Effect of Triisopropanolamine on the Hydration of Phosphorous Slag and Steel Slag | 10.1007/s11595-023-2829-7 |
2023-12-01 | Enhanced oxygen vacancy (V O ) has been designated as an effective strategy to prepare high-performance MnO 2 nanocatalysts for the oxidation of volatile organic compounds (VOC) for thereof unbalanced electronic structure, and rapid electron transfer which may even reduce the reaction temperature down to room temperature. Herein, the effects of the V O on the catalytic performance of nano-sized MnO 2 were discussed by classifying the V O into surface-anchored and bulk-involved ones. Currently used introducing and modulating methods for V O including elemental doping, energetic particle bombardment, atmosphere heat treatment, mechanical chemistry, and redox methods are detailly reviewed. Corresponding regulating mechanisms for V O are expounded. Commonly used characterization methods including ESR, XPS, HRTEM, and UV-vis are reviewed. Furtherly, the unveiled question which is highly expected to be answered on V O of MnO 2 nanocatalysts is proposed. The purpose of this review is to present the current status of research on MnO 2 nanoparticles and to provide researchers with basic research ideas. | Recent Advances in the Regulation of Oxygen Vacancies in MnO2 Nanocatalysts | 10.1007/s10563-023-09402-1 |
2023-12-01 | Jackfruit peels are potential waste for valorization and extraction of pectin and quality of pectin is a function of extraction conditions. Present study evaluates the effect of low temperature (LT) extraction; mediated through ultrasonication on the quality of pectin from jackfruit peel waste (JP). We first optimized ultrasound assisted extraction (UAE) process through response surface methodology (RSM) based on a Box-Behnken design (BBD) and arrived at optimal extraction conditions with maximum pectin yield and galacturonic acid content (GalA). Pectin extracted at LT and conventional high temperature (HT) referred as UAE-P and CE-P respectively were compared for their technological and structural properties. GalA content ranged between 65.53 and 68.65% in CE-P and UAE-P respectively. UAE-P had methoxyl content (5.58), protein (1.69%), molecular weight (149.67), total phenolic content (1645 mg GAE/100 g), and antioxidant capacity (123.76 µmol TE/g). There were significant (p < 0.05) differences in the Arabinose (Ara) content, FTIR spectra and functionality of pectin extracted at LT and HT. The Ara content was ~ twofold higher while antioxidant activity was ~ 1.66-fold higher in LT extracted UAE-P pectin. Hypoglycemic activity as determined by in vitro α–amylase and α–glucosidase inhibitory activity was significantly higher (p < 0.05) in UAE-P in comparison to CE-P. The DE value of UAE-P (38.11%) was low (< 50%) thus it was categorized as low methoxyl pectin. Results suggests that the UAE is potential efficient green method to obtain high quality food grade pectin with higher yield and functionality in short duration. Graphical abstract | Extraction and characterization of ultrasound assisted extraction: improved functional quality of pectin from jackfruit (Artocarpus heterophyllus Lam.) peel waste | 10.1007/s11694-023-02126-w |
2023-12-01 | Development of block copolymer (BCP) microparticles with switchable morphology in response to external stimuli is important for exploiting new intelligent materials. In this work, thermo/pH dual-responsive nanoparticles (NPs) were employed as a co-surfactant to modulate the self-assembly morphology of polystyrene- b -poly(2-vinylpyridine) (PS- b -P2VP) microparticles within confined emulsion droplets. The co-surfactant was synthesized by grafting poly(acrylic acid)- b -poly( N -isopropylacrylamide) onto the surface of Fe 3 O 4 NP. The introduction of the dual-responsive co-surfactant enabled thermo/pH dual-responsive reversible morphology transition of the PS- b -P2VP microparticles by tailoring the hydrophobicity and interfacial affinity of the co-surfactant. By using this strategy, the thermo-inert PS- b -P2VP self-assembled into pupa-like microparticles at T = 10 °C and pH 7.5, which could transform into tulip-like microparticles when T was increased to 50 °C. When the pH value was increased to 11, the pupa-like particles turned into onion-like microparticles although the PS- b -P2VP was inert to alkali. However, the pupa-like microparticles remained unchanged when both T and pH were simultaneously increased. The PAA- b -PNIPAM-grafted Fe 3 O 4 NP surfactants showed obvious advantages over the linear PAA- b -PNIPAM surfactants in modulating the morphology transition, since the linear PAA- b -PNIPAM could not induce the reversible shape transition of microparticles. Our work provides an efficient strategy to achieve reversible shape transformation of BCP microparticles while the internal phase structure is preserved, which may be utilized to switch the structural color properties of BCP microparticles. | Temperature/pH dual-responsive reversible morphology evolution of block copolymer microparticles under three-dimensional confinement | 10.1007/s11426-023-1714-1 |
2023-12-01 | The progressive use of dyes in various industrial sectors, such as textiles, paints, paper, and personal care products, has posed a severe threat to humankind. Different research groups in the last couple of decades have contributed significantly to providing some solution to such dye contamination. Such reports exhibit varying degrees of removal depending upon experimental constraints. This review article summarizes the dye removal efficiency offered by natural and synthetic adsorbents with a comparative discussion. Natural adsorbents, including plant-based materials, are known for their easy availability, cost-effectiveness, non-toxicity, sustainability, biodegradability, and eco-friendliness. On the other hand, synthetic adsorbents enjoy an edge over natural ones with high surface area, up-scale production, high efficiency, water stability, and specificity. This review comprehensively summarizes the effects of various physicochemical factors, kinetics, and isotherms on adsorption, along with related thermodynamic interpretations. Mechanistic forces that are responsible for adsorbate–adsorbent binding have been interpreted. A comparative study of natural and synthetic adsorbents adds flavor to the entire article. The scope of future work has been suggested with possible solutions. Graphical abstract | Dye sequestration from aqueous phase using natural and synthetic adsorbents in batch mode: present status and future perspectives | 10.1007/s13762-023-04782-3 |
2023-12-01 | The paper aims to study low-velocity impact behavior on the synergistic effect of intralaminar carbon/glass hybridization and three-dimensional (3D) orthogonal woven structure. A drop-testing machine is used for impact tests considering the effects of impact energy ranging from 23 J to 70 J. Nondestructive testing methods and a realistic yarn-level finite element model accounting for material damage are implemented to study structure deformation and stress evolution. Simulation results are compared with experimental measurements, which show a good correlation. The impact response of three configurations of 3D orthogonal woven composites (3DOWCs) is evaluated in terms of residual deformation, maximum displacement, maximum peak load and inelastic energy with different impact energy levels. The results show the intralaminar hybridizing carbon yarns with glass yarns with greater strain (about 22.78% more than the structure of pure carbon fibers) to failure benefits the toughness performance and energy absorption of the 3DOWCs, especially for the structure that glass fibers used as weft yarns. The stress in each layer travels along with the yarn axis due to the discontinuity between the same type of yarns. In contrast, the compressive stress along the thickness direction is transferred to the lower layer by the overlapping points, further resulting in stress along the yarn axis in the next layer. These findings are of guiding significance for the design of complex 3D fabrics. | Impact Response of 3D Orthogonal Woven Composites with Different Fiber Types | 10.1007/s10443-023-10150-8 |
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