publicationDate stringlengths 10 10 | abstract stringlengths 0 37.3k | title stringlengths 1 5.74k | doi stringlengths 11 47 ⌀ |
|---|---|---|---|
2020-12-01 | Background Air pollution is a global problem with PM 2.5 being one of the major pollutants causing many diseases. The concentrations of PM 2.5 are found to exceed the World Health Organization (WHO) standards especially in lower middle-income countries (LMICs) that house around 40% of the global population. Materials and Methods Studies conducted globally in the past 5 years (2015–2019) on health effects of PM2.5 were systematically reviewed to understand the current research gaps. For this systematic search, Web of Science and PubMed were used to obtain 247 articles. Results Systematic review of these studies revealed that PM 2.5 and other air pollutants have been found to be associated with increased mortality and morbidity due to respiratory, cardiovascular, cerebrovascular disorders and diabetes. However, most of the total studies (~ 69%) were carried out in the high-income countries (HICs) despite the fact that PM 2.5 concentrations are higher in the LMICs (annual mean exposure (2011–2017) of 48.42 µg/m 3 ) and lower in the HICs (annual mean exposure (2011–2017) of 20.02 µg/m 3 ). Therefore, the exposure response functions for mortality estimates associated with PM 2.5 and developed using the exposure data from the HICs will not have predictive value in the LMICs. Furthermore, very few studies relate chemical components and source apportionment of PM 2.5 to the associated toxicity. Conclusions More studies on morbidity and mortality associated with PM2.5 and its components are needed in LMICs for better estimation of the overall risks. | Health Effects Associated with PM2.5: a Systematic Review | 10.1007/s40726-020-00155-3 |
2020-12-01 | Blood chemistry of growing male pigs fed low crude protein (CP) and low-energy diets supplemented with multi-enzyme was determined using 36 male pigs aged 8–10-weeks old. Two metabolizable energy (3000 and 2600 kcal ME /kg) and three protein (18, 16, and 14% CP) levels were used to formulate 6 treatment diets: T1 (3000 kcal ME/kg and 18% CP), T2 (3000 kcal ME/Kg and 16% CP), T3 (3000 kcal ME/kg and 14% CP), T4 (2600 kcal ME/kg and 18% CP), T5 (2600 kcal ME/kg and 16% CP) and T6 (2600 kcal ME/kg and 14% CP). T1 served as the control diet, while T2–T6 was supplemented with 1.0 g enzyme/kg feed each. The treatments were replicated thrice with two pigs per replicate in a 2 × 3 factorial and analysed statistically. Serum total protein, albumin, globulin, albumin/globulin ratio, urea, creatinine, urea/creatinine ratio, cholesterol, alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) were analysed. Low-energy diets (3000 and 2600 kcal ME/kg) plus enzyme supplementation did not affect ( P > 0.05) any of the serum parameter measured. Also, dietary low CP level plus enzyme supplementation influenced ( P < 0.05) aspects of the serum parameters. Higher ( P < 0.05) total protein, albumin and creatinine were noticed in pigs fed with T2 diet; while pigs fed with T4 diet had higher ( P < 0.05) urea compared with those on the other 5 treatment diets. Significant dietary interaction effects ( P < 0.05) were observed on cholesterol, ALT, AST and ALP. The quadratic regression model revealed that aspects of serum parameters in pigs were optimized at different low-protein and low-energy levels. In conclusion, the results suggest that pigs on T2 diet had the best serum parameters. | Blood chemistry of growing male pigs in response to low protein and energy diets with EnziBlend Plus supplementation | 10.1007/s00580-020-03163-3 |
2020-12-01 | Abstract— Electrodynamic properties of a low-pressure (electron collision frequency much lower than the field frequency) capacitive high-frequency (HF) discharge with large-area electrodes maintained by an electromagnetic field with frequency higher than 13 MHz is studied analytically. The discharge is sustained by surface waves propagating along the plasma–space-charge sheath–metal interface. When describing the sheath, dispersion curves for even and odd surface waves in a three-layer structure (sheath–plasma–sheath) surrounded by metal boundaries are calculated within the framework of the matrix model. It is demonstrated that the field of the fundamental mode (the quasi-TEM mode) must be taken into account for correct discharge impedance calculation in the case of low electron densities, while the field of the surface wave must be taken into account in the case of high electron densities. An approximate expression governing the discharge impedance that is based on accounting only for one mode is derived. The expression is valid at low electron densities when the surface waves are absent, as well as high electron densities exceeding the value giving rise to a geometric resonance in the plasma–sheath system. | Features of Electromagnetic Field Excitation in a Capacitive HF Discharge. I. General Aspects. A Simple Model of Symmetric Discharge | 10.1134/S1063780X20120028 |
2020-12-01 | A low-noise amplifier (LNA) topology with tunable input matching and noise cancellation is introduced and described in this paper, which was designed and optimized to interface with a magnetoelectric (ME) antenna in a 0.35 µm MEMS-compatible CMOS process. Compared to conventional antennas, acoustically actuated ME antennas have significantly smaller area for ease of integration. The LNA was simulated with an ME antenna model that was constructed based on antenna measurements. Input matching at the LNA-antenna interface is controlled with a circuit that varies the effective impedance of the gate inductor using a control voltage. Tunability of 455 MHz around 2.4 GHz is achieved for the optimum S11 frequency with a control voltage range of 0.3–1.2 V. The proposed LNA has a noise cancelling feedback loop that improves the noise figure by 4.1 dB. The post-layout simulation results of the LNA show a 1-dB compression point of – 7.4 dBm with an S 21 of 17.8 dB. | Integration of a novel CMOS-compatible magnetoelectric antenna with a low-noise amplifier and a tunable input matching | 10.1007/s10470-020-01721-x |
2020-12-01 | Abstract A method for excitation of thorium-229 isomeric nuclei the electron beam irradiation of a solid-state target based on thorium silicate is considered. The key point for obtaining an effective yield of isomeric nuclei is the generation of secondary electrons with a significant increase in the multiplication factor for electrons that have energies within a range from 1 to 25 keV. Based on numerical simulation and theoretical estimation of the excitation cross section of isomeric transition in inelastic scattering, the yield function of isomeric nuclei was o qualitatively obtained. | ThSi10O22 Compound as Target for Production of Isomeric Thorium-229 Nuclei at Electron Beam Irradiation | 10.1134/S1063778820090021 |
2020-12-01 | Objective To verify the photobiomodulation effect on angiogenic proteins produced and released by dental human pulpal fibroblasts (HPFs). Material and methods HPFs were irradiated with 660-nm low-level laser at fluences of 2.5 J/cm 2 and 3.7 J/cm 2 . The control group was not irradiated. MTT, crystal violet, and ELISA assays respectively verified viability, proliferation, and angiogenic protein (supernatant/lysate) at 6 h, 12 h, and 24 h after photobiomodulation. Capillary-like structure formation assay verified functional role. Two-way ANOVA/Tukey’s test and ANOVA/Bonferroni’s multiple comparisons test respectively verified cell viability/proliferation and intragroup and intergroup comparisons of protein synthesis ( p < 0.05). Results Irradiated and non-irradiated HPFs showed statistically similar cell viability and proliferation pattern. Intragroup comparisons showed similar patterns of protein synthesis for all groups: VEGF-A, VEGF-C, and vascular endothelial growth factor receptor 1 (VEGFR1) increased significantly in the supernatant, while FGF-2 and VEGF-A increased significantly in the lysate. The lower fluence significantly increased BMP-9 (6 h) in the supernatant and VEGFR1 (6 h and 12 h) and VEGF-D (24 h) in the lysate, while the higher fluence significantly increased BMP-9 (6 h) in the supernatant and VEGFR1 (12 h) in the lysate. Regardless of the time, both fluences statistically downregulated placental growth factor (PLGF) and PDGF secretion. Both fluences statistically decreased VEGF-A secretion (24 h) and PLGF production (6 h). Conclusion Photobiomodulation produced stimulatory effects on angiogenic protein secretion by pulp fibroblasts. In terms of photobiomodulation, over time, both fluences significantly increased the secretion of VEGF-A, VEGF-C, and VEGFR1 and significantly upregulated BMP-9 (6 h) in the supernatant; for capillary-like structure formation, the fluence of 2.5 J/cm 2 was better than the fluence of 3.7 J/cm 2 . Clinical relevance This study results addressed effective photobiomodulation parameters tailored for pulp angiogenesis. | Photobiomodulation effect on angiogenic proteins produced and released by dental pulp cells | 10.1007/s00784-020-03298-1 |
2020-12-01 | Introduction Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) is an established treatment for pseudomyxoma peritonei (PMP) from perforated low-grade appendiceal mucinous neoplasms (LAMN II). In a selected group of LAMN II patients without established PMP, CRS/HIPEC can be performed laparoscopically (L-CRS/HIPEC); however the short-term benefits and safety of this approach have yet to be determined. This study aims to determine the short-term outcomes from a series of L-CRS/HIPEC LAMN II patients compared to those who have undergone a similar open operation (O-CRS/HIPEC) for low-volume PMP. Methods LAMN II patients undergoing L-CRS/HIPEC at a UK national peritoneal tumour centre were compared to O-CRS/HIPEC patients (peritoneal cancer index ≤ 7). Outcomes of interest included Clavien–Dindo complication grade, operative time, blood transfusions, high dependency unit (HDU) admission, length of hospital stay, and histopathological findings. Results 55 L-CRS/HIPEC were compared to 29 O-CRS/HIPEC patients (2003–2017). Groups were matched for age, sex, and procedures. Median operative time was 8.8 (IQR 8.1–9.5) h for L-CRS/HIPEC versus 7.3 (IQR 6.7–8) h for O-CRS/HIPEC (Mann–Whitney test p < 0.001). Post-operative HDU admission was 56% versus 97% (OR 0.04 95% CI 0.01–0.34) and median length of stay = 6 (IQR 5–8) versus 10 (IQR 8–11) days ( p < 0.001) for L- versus O-CRS/HIPEC. Despite a normal pre-operative CT scan, 13/55 (23.6%) L-CRS/HIPEC patients had acellular mucin and 2/55 (3.5%) had mucin with epithelium present in their specimens. Residual appendix tumour was identified in 2/55 patients (3.6%). Clavien–Dindo Grade 1–4 complications were similar in both groups with no mortality. Conclusion L-CRS/HIPEC for LAMN II takes longer; however patients have significantly reduced length of HDU and overall stay, without increased post-operative complications. A significant proportion of LAMN II patients undergoing L-CRS/HIPEC have extra-appendiceal acellular mucin with some cases demonstrating residual cellular epithelium from the LAMN II. The risk of these patients developing PMP without surgery is under current review. | Laparoscopic cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for perforated low-grade appendiceal mucinous neoplasms | 10.1007/s00464-019-07349-x |
2020-12-01 | Sound absorbing elements commonly used to make quieter spaces are very desirable for high-frequency noise control. It is more attractive if it is possible to produce sound absorbing structures that perform well for a wide frequency range, especially in low-frequencies. In this regard, Helmholtz resonator array is a well-known structure but the maximum performance of each resonator unit in an array panel can only be achieved at resonance frequency that is dependent on its size. Therefore, a resonator array panel with equal size units has insufficient performance in a wide frequency range. Hence, the consideration of suitable sizes for each resonator in an array panel consisting of unequal size units is a key point to widen the frequency range of sound absorption. On the other hand, it seems that engineering science can be developed by nature inspiration. In addition, Fibonacci sequence is a famous mathematical model which describes the shape/ratio of different phenomena which exist in nature. In this paper, Fibonacci sequence is utilized to investigate Helmholtz resonator arrangement to increase both the amount of sound absorption coefficient and frequency bandwidth of absorption without changing the total volume of resonator array with equal size units. Analytical solutions based on the modified equivalent electrical circuit theory is used to calculate the sound absorption coefficient of the proposed panel with numerical experiments in MAPLE and COMSOL Multiphysics softwares to validate the proposed overall approach. Results show that the Fibonacci sequence is an optimum candidate to design a resonator-based sound absorber in low-frequency noise. | Innovative solution to enhance the Helmholtz resonator sound absorber in low-frequency noise by nature inspiration | 10.1007/s40201-020-00512-w |
2020-12-01 | Abstract The adsorption and protective properties of three thiadiazole derivatives on St3 steel from 5 and 15% H 2 SO 4 solutions have been studied by the method of impedance spectroscopy. A series of changes in absorbability and protective effect depending on the compound structure have been determined. Equivalent electrical circuits have been suggested, and numerical values of circuit parameters have been determined at the compounds' different concentrations. The degree of occupation of the electrode surface by the studied compounds at the corrosion potential has been calculated. | Adsorption of a Series of Thiadiazole Derivatives on Low-Carbon Steel from Sulfuric Acid Solutions | 10.1134/S2070205120070151 |
2020-12-01 | Abstract The paper presents the results of studying the efficiency of using ionizing radiation to modify the surface morphology and structural properties of TiO 2 thin films, and the effect of ion modification on the photocatalytic activity of Rhodamine B. decomposition. Structural and morphological changes in thin films were characterized by irradiation with doses of 10 14 –10 16 ion/cm 2 using scanning electron microscopy, atomic force microscopy, energy-dispersive analysis and X-ray diffraction. Modification by ion irradiation of thin films leads to a change in grains orientation, a decrease in their size, and an increase in the active surface area. Formation of grains preferred orientation at high radiation doses is caused both by grains rotation as a result of distorting and deformation factors caused by radiation, and by grains partial fragmentation. It was shown that in the case of modified samples of thin films, not only an increase in the rate decomposition reaction constant by 2–4.5 times compared with the initial samples, but also the degree of mineralization is observed. According to the data obtained, the maximum value of mineralization as a result of photocatalytic reactions for initial films was no more than 75–76%. While for irradiated samples, this value varies from 83 to 90% depending on the irradiation dose. For modified films, an increase in crack resistance and resistance to degradation to prolonged tests of photocatalytic activity is observed. Graphic abstract | The study of the applicability of ionizing radiation to increase the photocatalytic activity of TiO2 thin films | 10.1007/s40097-020-00353-x |
2020-12-01 | This paper studies the pathways of peaking CO 2 emissions of Dezhou city in China, by employing a bottom-up sector analysis model and considering future economic growth, the adjustment of the industrial structure, and the trend of energy intensity. Two scenarios (a business-as-usual (BAU) scenario and a CO 2 mitigation scenario (CMS)) are set up. The results show that in the BAU scenario, the final energy consumption will peak at 25.93 million tons of coal equivalent (Mtce) (16% growth versus 2014) in 2030. In the CMS scenario, the final energy will peak in 2020 at 23.47 Mtce (9% lower versus peak in the BAU scenario). The total primary energy consumption will increase by 12% (BAU scenario) and decrease by 3% (CMS scenario) in 2030, respectively, compared to that in 2014. In the BAU scenario, CO 2 emission will peak in 2025 at 70 million tons of carbon dioxide (MtCO 2 ), and subsequently decrease gradually in 2030. In the CMS scenario, the peak has occurred in 2014, and 60 MtCO 2 will be emitted in 2030. Active policies including restructuring the economy, improving energy efficiency, capping coal consumption, and using more lowcarbon/carbon free fuel are recommended in Dezhou city peaked CO 2 emission as early as possible. | Peak CO2 emission in the region dominated by coal use and heavy chemical industries: A case study of Dezhou city in China | 10.1007/s11708-018-0558-y |
2020-12-01 | There are several approaches for improving neural machine translation for low-resource languages: monolingual data can be exploited via pretraining or data augmentation; parallel corpora on related language pairs can be used via parameter sharing or transfer learning in multilingual models; subword segmentation and regularization techniques can be applied to ensure high coverage of the vocabulary. We review these approaches in the context of an asymmetric-resource one-to-many translation task, in which the pair of target languages are related, with one being a very low-resource and the other a higher-resource language. We test various methods on three artificially restricted translation tasks—English to Estonian (low-resource) and Finnish (high-resource), English to Slovak and Czech, English to Danish and Swedish—and one real-world task, Norwegian to North Sámi and Finnish. The experiments show positive effects especially for scheduled multi-task learning, denoising autoencoder, and subword sampling. | Transfer learning and subword sampling for asymmetric-resource one-to-many neural translation | 10.1007/s10590-020-09253-x |
2020-12-01 | Background The COVID-19 pandemic outbreak has set the emergency services in developing countries on major alert, as the installed response capacities are easily overwhelmed by the constantly increasing high demand. The deficit of intensive care unit beds and ventilators in countries like Peru is forcing practitioners to seek preventive or early interventional strategies to prevent saturating these chronically neglected facilities. Case presentation A 64-year-old patient is reported after presenting with COVID-19 pneumonia and rapidly progressing to deteriorated ventilatory function. Compassionate treatment with a single 1‑Gy dose to the bilateral whole-lung volume was administered, with gradual daily improvement of ventilatory function and decrease in serum inflammatory markers and oxygen support needs, including intubation. No treatment-related toxicity developed. Procedures of transport, disinfection, and treatment planning and delivery are described. Conclusion Whole-lung low-dose radiotherapy seems to be a promising approach for avoiding or delaying invasive respiratory support. Delivered low doses are far from meeting toxicity ranges. On-going prospective trials will elucidate the effectiveness of this approach. | Low-dose radiotherapy for COVID-19 pneumonia treatment: case report, procedure, and literature review | 10.1007/s00066-020-01675-z |
2020-12-01 | Oxidized low-density lipoprotein (ox-LDL) modulates gene transcription and expression and induces the development of endothelium inflammation and endothelial dysfunction, in which microRNAs (miRNAs) play a crucial role. However, the mechanism of ox-LDL in inflammatory damage of endothelial cells still remains elusive. Herein, we focused on the effect of hsa-miR-217-5p (miR-217) on endothelial dysfunction induced by ox-LDL by targeting early growth response protein-1 (EGR1). In the present study, 31 upregulated miRNAs and 59 downregulated miRNAs (Fold Change > 2, P value < 0.05) were identified after 6 h of 80 μg/mL ox-LDL exposure in human aortic endothelial cells (HAECs) by small RNA sequencing, including miR-217 that was significantly decreased (FC = 0.2787, P value = 5.22E-16). MiR-217 knockdown inhibited cell proliferation and increased level of IL-6, IL-1β, ICAM-1 and TNF-α, while overexpression of miR-217 relieved the growth inhibition induced by ox-LDL and demonstrated anti-inflammatory effect in HAECs. EGR1 was predicted as a potential candidate target gene of miR-217 by TargetScan. The subsequent dual-luciferase reporter assay confirmed the direct binding of miR-217 to 3′UTR of EGR1. And EGR1 expression was negatively correlated with the level of miRNA-217 in HAECs after exposure to ox-LDL. Overexpression of EGR1 recapitulated the effects of miR-217 knockdown on cell proliferation inhibition and inflammation in HAECs, while knockdown EGR1 relieved the proliferative inhibition and demonstrated anti-inflammatory effect in ox-LDL-induced HAECs. The present study confirmed miR-217 ameliorates inflammatory damage of endothelial cells induced by oxidized LDL by targeting EGR1. | MicroRNA-217 ameliorates inflammatory damage of endothelial cells induced by oxidized LDL by targeting EGR1 | 10.1007/s11010-020-03857-w |
2020-12-01 | Low-salinity (LS) waterflooding has been a topic of substantial recent interest in the petroleum industry. Studies have shown that LS brine injection can increase oil production relative to high-salinity (HS) brine injection, but contradictory results have also been reported and a mechanistic explanation of these findings remains elusive. We have recently developed a pore-scale model of LS brine injection in uniformly wetted networks (Watson et al. in Transp Porous Med 118:201–223, 2017), and we extend this approach here to investigate the low-salinity effect (LSE) in heterogeneously wetted media. We couple a steady-state fluid displacement model to an innovative tracer algorithm and track the evolving salinity front as oil and HS brine are displaced from the network. The wettability of the pore structure is locally modified where water salinity falls below a critical threshold, and simulations show that this can have significant consequences for oil recovery. Our results demonstrate that, for heterogeneously wetted networks, the oil-wet (OW) pores are the only viable source of incremental oil by LS brine injection. Moreover, we show that a LS-induced increase in the displaced OW pore fraction is a necessary, but not sufficient, condition to guarantee additional oil production. Simulations further suggest that the initial OW pore fraction, the average network connectivity and the initial HS brine saturation are factors that can determine the extent of incremental oil recovery following LS brine injection. This study clearly highlights that the mechanisms of the LSE can be markedly different in uniformly wetted and in non-uniformly wetted porous media. | A Mechanistic Pore-Scale Analysis of the Low-Salinity Effect in Heterogeneously Wetted Porous Media | 10.1007/s11242-020-01488-9 |
2020-12-01 | The Japanese traditional fermented soybean or “natto”, a cheap and nutrient-rich food, is very popular in Japan. The low-phytate (LP) soybeans exhibit higher mineral bioavailability; however, their use in preparing natto has not been reported. Therefore, in this study, characteristics and quality of natto prepared using LP soybean were investigated. The findings revealed a better color, lower stickiness, and lower hardness and taste of LP natto with lower phytate and higher inorganic phosphorus (Pi) concentrations than those in the normal-phytate (NP) natto. However, the Ca, Mg, and K concentrations were not significantly different between LP and NP natto, whereas the protein level in NP natto was slightly higher than that in LP natto. These findings indicate that the lower phytate content in LP natto than that in NP natto, could facilitate a higher bioavailability of P and other minerals. Moreover, the improved color and lower stickiness, in addition to lower hardness and taste of LP natto, imparted through improved manufacturing process could increase its acceptability overseas, thereby increasing its commercial value. These improved qualities of LP natto could contribute to improving human health as well as increasing sustainable food and nutrient security. | Characteristics and Quality of Japanese Traditional Fermented Soybean (Natto) from a Low-phytate Line | 10.1007/s11130-020-00865-5 |
2020-12-01 | Background Local tissue damage caused by electrical burns is often deep and severe. High-voltage electrical burns are common in the head, neck and torso areas. These are mostly caused by direct contact with the power supply and are often accompanied by deep injuries of the nerve, blood vessel, muscle, tendon, and bone. We must pay great attention to the clinical treatment of these parts injured by electrical burn. Case presentation The first case involved a migrant worker who touched a 6-kV high-tension wire when welding steel; this electric shock caused burns in many places. Deep electrical burn wounds were mainly located on the left shoulder and back, characterized by widespread skin and soft tissue defect and bone necrosis. We utilized a lower trapezius myocutaneous flap to repair these wounds in the neck and back caused by deep electrical burns. The flap survived completely and the wound was effectively repaired. The function and shape of the shoulder and back after the restoration were satisfactory. The second case involved a 29-year-old who accidentally touched a high-voltage wire while working and was burned by a 30,000-V electric shock. His wounds were mainly located on the left head, neck, back and left upper limbs. We designed a 30 cm × 12 cm right trapezius myocutaneous flap which completely covered the wound surface; the electrical burn wounds on the neck and back were effectively repaired. After the electrical burn wound was repaired, the neck function returned to normal with a satisfactory shape. Conclusion The authors report two cases of patients who were burned by high voltage. We used lower trapezius myocutaneous flaps to repair their wounds, which achieved satisfactory clinical results. This study has provided a reliable surgical method for the clinical treatment of deep electrical burn wounds in the neck, shoulders and back. | Lower trapezius myocutaneous flap repairs adjacent deep electrical burn wounds | 10.1186/s40001-020-00465-8 |
2020-12-01 | This study quantified the effect of weeding frequency and weeding schedules on weeding operation time in a sugi ( Cryptomeria japonica ) plantation stand. A weeding operation time estimation model was developed; then the cumulative weeding operation time after six growing seasons was simulated using the developed model. The developed model included weed height, relative height of weeds to sugi, and initial planting density. The simulated cumulative weeding operation time decreased approximately 6% for each one-treatment decrease in weeding frequency. Under a three-treatment weeding frequency scenario, the simulated cumulative operation time when weeding was conducted during non-consecutive years was longer than that when weeding was conducted during three consecutive years. The results suggest that carrying out weeding treatment during consecutive years is the more effective for reduction of weeding costs. We conclude that weeding schedule as well as weeding frequency must be considered for reduction of weeding operation time. | The effect of weeding frequency and schedule on weeding operation time: a simulation study on a sugi (Cryptomeria japonica) plantation in Japan | 10.1007/s11676-019-01017-5 |
2020-12-01 | Since February 21, 2020, SARS-CoV-2 has spread exponentially worldwide. Neonatal patients needing intensive care are considered a vulnerable population. To report the results of a policy based on multi-timepoint surveillance for SARS-CoV-2 of all neonates admitted to the neonatal intensive care unit (NICU), their parents, and all healthcare providers in a part of Italy with a high prevalence of the infection. Observational study conducted from 21 February to 21 April 2020. Intervention consisted of (a) parental triage on arrival at the neonatal ward; (b) universal testing with nasopharyngeal swabs and blood testing for SARS-CoV-2 IgM and IgG antibodies; (c) use of continuous personal protective equipment at the NICU by parents and staff. A total of 6726 triage procedures were performed on 114 parents, and 954 nasopharyngeal swabs were collected from 226 individuals. Five (2.2%) asymptomatic individuals (2 parents and 3 healthcare providers) tested positive on nasopharyngeal swabs and were kept isolated for 14 days. Of 75 admitted newborn, no one tested positive on nasopharyngeal swabs or antibody tests. Three parents presented with fever or flu-like symptoms at triage; they tested negative on swabs. Conclusion : With universal screening of neonates, parents, and staff, there were no cases of SARS-CoV-2 infection among the neonates admitted to a NICU in an area with a high incidence of SARS-CoV-2. Our experience could be usefully compared with other strategies with a view to developing future evidence-based guidelines for managing high-risk neonates in case of new epidemics. What is Known: • The novel coronavirus named SARS-CoV-2 has since spread worldwide at a remarkable rate, with more than 2.5 million confirmed cases. • Pediatric population may be less affected from COVID-19 than adult population but infants and newborn babies seem to be more vulnerable to SARS-CoV-2 infection. What is New: • Using an approach based on triage; testing with nasopharyngeal swabs and serology; and use of personal protective equipment, there were no cases of SARS-CoV-2 infection among neonates in a NICU in a high incidence of SARS-CoV-2 area. • Positive and asymptomatic individuals were identified and isolated early allowing the containment of infection’s spread among healthcare providers and parents. | Universal screening of high-risk neonates, parents, and staff at a neonatal intensive care unit during the SARS-CoV-2 pandemic | 10.1007/s00431-020-03765-7 |
2020-12-01 | Purpose of Review The role of pelvic neurophysiology testing in the evaluation of patients with lower urinary tract (LUT) symptoms is explored in this review. Recent Findings Different neurophysiology tests such as sphincter EMG and pudendal somatosensory evoked potentials are useful in evaluating the sacral somatic afferent and efferent innervation. S2 and S3 dermatomal evoked potentials assess individual sacral roots and are feasible to perform using standard neurophysiology machines. Summary The innervation of the LUT has a substantial contribution from splanchnic and somatic nerves arising from the sacral segments. Pelvic neurophysiology tests, which assess somatic nerve functions, are therefore a useful tool in assessing sacral nerve functions in patients presenting with unexplained voiding dysfunction. In this review, the commonly performed neurophysiology studies that assess the S2, S3 and S4 sacral afferent and efferent pathways are outlined, and their clinical applications reviewed. | The Role of Pelvic Neurophysiology Testing in the Assessment of Patients with Voiding Dysfunction | 10.1007/s11884-020-00613-0 |
2020-12-01 | Fixed-bed bioreactors packed with macrocarriers show great potential to be used for vaccine process development and large-scale production due to distinguishing features of low shear force, high cell adhering surface area, and easy replacement of culture media in situ. As an initial step of utilizing this type of bioreactors for Pseudorabies virus production (PRV) by African green monkey kidney (Vero) cells, we developed a tube-fixed-bed bioreactor in the previous study, which represents a scale-down model for further process optimization. By using this scale-down model, here we evaluated impacts of two strategies (use of serum-free medium and low cell inoculum density) on PRV production, which have benefits of simplifying downstream process and reducing risk of contamination. We first compared Vero cell cultures with different media, bioreactors and inoculum densities, and conclude that cell growth with serum-free medium is comparable to that with serum-containing medium in tube-fixed-bed bioreactor, and low inoculum density supports cell growth only in this bioreactor. Next, we applied serum-free medium and low inoculum cell density for PRV production. By optimization of time of infection (TOI), multiplicity of infection (MOI) and the harvesting strategy, we obtained total amount of virus particles ~ 9 log 10 TCID 50 at 5 days post-infection (dpi) in the tube-fixed-bed bioreactor. This process was then scaled up by 25-fold to a Xcell 1-L fixed-bed bioreactor, which yields totally virus particles of 10.5 log 10 TCID 50, corresponding to ~ 3 × 10 5 doses of vaccine. The process studied in this work holds promise to be developed as a generic platform for the production of vaccines for animal and human health. | Pseudorabies virus production using a serum-free medium in fixed-bed bioreactors with low cell inoculum density | 10.1007/s10529-020-02987-x |
2020-12-01 | The rotor blade of an experiment turbine for low Reynolds number flow conditions is recontoured on the hub endwall to reduce the hub’s secondary flow losses. The baseline rotor blade is radially stacked with airfoils of free vortex twisting. The hub section airfoil of the rotor blade is reprofiled for three considerations. The first is to reduce the inlet metal angle to fit with the vane’s exit flow angle near the hub endwall. The second is to reduce the airfoil’s stagger angle to reduce the pitchwise pressure gradient on the hub endwall. The third is to extend the airfoil’s axial chord to a limited distance before the baseline one to build a leading edge fillet. A steady RANS flow computation is carried out to compare the flow fields inside the baseline and the new contoured rotor passages. Flow comparison reveals that the passage vortex intensity is reduced and that the total pressure loss is reduced by 8.9 % in the hub region. The new contoured rotor shows potential application in reducing rotor secondary losses through the stacking of two-dimensional sectional airfoils. | Reducing rotor secondary losses in a turbine stage through endwall airfoil profiling | 10.1007/s12206-020-2104-1 |
2020-12-01 | By applying monotone iterative technique coupled with the method of lower and upper solutions, sufficient conditions are obtained for the existence of mild solution of Sobolev type fractional integro-differential equations with fractional nonlocal conditions. The results are obtained under monotonicity and measure of noncompactness conditions of the nonlinear functions. At last, an example is given to show the applicability of main results. | Monotone iterative technique for Sobolev type fractional integro-differential equations with fractional nonlocal conditions | 10.1007/s12215-019-00447-8 |
2020-11-30 | One of the major applications of Wireless Body Area Networks (WBANs), and the Internet of Things is the Electronic Health-Care systems. The progress in WBANs, and implanted health monitoring technologies have strong potential to alter the future of healthcare services by enabling ubiquitous monitoring of patients. An energy-efficient protocol is an important factor in the operation of eHealth care systems. A hybrid energy-efficient routing protocol is proposed in this paper for the distributed wireless body area network. In which a hybrid communication method and a new synchronization scheme are discussed. The hybrid communication enhances the network lifetime, and the synchronization scheme will consume less energy by avoiding collisions. The performance of the proposed protocol is analyzed, and it is compared with three baseline routing protocols at the 2.4 GHz ISM band with two ultra-low power transceivers. | A hybrid energy-efficient routing protocol for wireless body area networks using ultra-low-power transceivers for eHealth care systems | 10.1007/s42452-020-03900-x |
2020-11-30 | Background Most studies have shown that maternal age is associated with birth weight. However, the specific relationship between each additional year of maternal age and birth weight remains unclear. The study aimed to analyze the specific association between maternal age and birth weight. Methods Raw data for all live births from 2015 to 2018 were obtained from the Medical Birth Registry of Xi’an, China. A total of 490,143 mother-child pairs with full-term singleton live births and the maternal age ranging from 20 to 40 years old were included in our study. Birth weight, gestational age, neonatal birth date, maternal birth date, residence and ethnicity were collected. Generalized additive model and two-piece wise linear regression model were used to analyze the specific relationships between maternal age and birth weight, risk of low birth weight, and risk of macrosomia. Results The relationships between maternal age and birth weight, risk of low birth weight, and risk of macrosomia were nonlinear. Birth weight increased 16.204 g per year when maternal age was less than 24 years old (95%CI: 14.323, 18.086), and increased 12.051 g per year when maternal age ranged from 24 to 34 years old (95%CI: 11.609, 12.493), then decreased 0.824 g per year (95% CI: -3.112, 1.464). The risk of low birth weight decreased with the increase of maternal age until 36 years old (OR = 0.917, 95%CI: 0.903, 0.932 when maternal age was younger than 27 years old; OR = 0.965, 95%CI: 0.955, 0.976 when maternal age ranged from 27 to 36 years old), then increased when maternal age was older than 36 years old (OR = 1.133, 95%CI: 1.026, 1.250). The risk of macrosomia increased with the increase of maternal age (OR = 1.102, 95%CI: 1.075, 1.129 when maternal age was younger than 24 years old; OR = 1.065, 95%CI: 1.060, 1.071 when maternal age ranged from 24 to 33 years old; OR = 1.029, 95%CI: 1.012, 1.046 when maternal age was older than 33 years old). Conclusions For women of childbearing age (20–40 years old), the threshold of maternal age on low birth weight was 36 years old, and the risk of macrosomia increased with the increase of maternal age. | Changing trends of birth weight with maternal age: a cross-sectional study in Xi’an city of Northwestern China | 10.1186/s12884-020-03445-2 |
2020-11-30 | Background Telemedicine has been a popular tool to overcome the lack of access to healthcare facilities, primarily in underprivileged populations. We aimed to describe and assess the implementation of a tele-electrocardiography (ECG) program in primary care settings in Indonesia, and subsequently examine the short- and mid-term outcomes of patients who have received tele-ECG consultations. Methods ECG recordings from thirty primary care centers were transmitted to Makassar Cardiac Center, Indonesia from January to July 2017. We cross-sectionally measured the performance of this tele-ECG program, and prospectively sent a detailed questionnaire to general practitioners (GPs) at the primary care centers. We performed follow-up at 30 days and at the end of the study period to assess the patient outcomes. Results Of 505 recordings, all (100%) ECGs were qualified for analysis, and about half showed normal findings. The mean age of participants was 53.3 ± 13.6 years, and 40.2% were male. Most (373, 73.9%) of these primary care patients exhibited manifested CVD symptom with at least one risk factor. Male patients had more ischemic ECGs compared to women ( p < 0.01), while older age (> 55 years) was associated with ischemic or arrhythmic ECGs ( p < 0.05). Factors significantly associated with a normal ECG were younger age, female gender, lower blood pressure and heart rate, and no history of previous cardiovascular disease (CVD) or medication. More patients with an abnormal ECG had a history of hypertension, known diabetes, and were current smokers ( p < 0.05). Of all tele-consultations, GPs reported 95% of satisfaction rate, and 296 (58.6%) used tele-ECG for an expert opinion. Over the total follow-up (14 ± 6.6 months), seven (1.4%) patients died and 96 (19.0%) were hospitalized for CVD. Of 88 patients for whom hospital admission was advised, 72 (81.8%) were immediately referred within 48 h following the tele-ECG consultation. Conclusions Tele-ECG can be implemented in Indonesian primary care settings with limited resources and may assist GPs in immediate triage, resulting in a higher rate of early hospitalization for indicated patients. | Tele-ECG consulting and outcomes on primary care patients in a low-to-middle income population: the first experience from Makassar telemedicine program, Indonesia | 10.1186/s12875-020-01325-4 |
2020-11-30 | Background Babies born weighing ≥ 2500 g account for more than 80% of the births in most resource-limited locations and for nearly 50% of the 28-day neonatal deaths. In contrast, in high-resource settings, 28-day neonatal mortality among this group represents only a small fraction of the neonatal deaths. Yet mortality risks for birth weight of ≥ 2500 g is limited. Knowledge regarding the factors associated with mortality in these babies will help in identifying interventions that can reduce mortality. Methods The Global Network’s Maternal Newborn Health Registry (MNHR) is a prospective, population-based observational study that includes all pregnant women and their pregnancy outcomes in defined geographic communities that has been conducted in research sites in six low-middle income countries (India, Pakistan, Democratic Republic of Congo, Guatemala, Kenya and Zambia). Study staff enroll all pregnant women as early as possible during pregnancy and conduct follow-up visits to ascertain delivery and 28-day neonatal outcomes. We analyzed the neonatal mortality rates (NMR) and risk factors for deaths by 28 days among all live-born babies with a birthweight ≥ 2500 g from 2010 to 2018 across the Global Network sites. Results Babies born in the Global Network sites from 2010 to 2018 with a birthweight ≥ 2500 g accounted for 84.8% of the births and 45.4% of the 28-day neonatal deaths. Among this group, the overall NMR was 13.1/1000 live births. The overall 28-day NMR for ongoing clusters was highest in Pakistan (29.7/1000 live births) and lowest in the Zambian/Kenyan sites (9.3/1000) for ≥ 2500 g infants. ≥ 2500 g NMRs declined for Zambia/Kenya and India. For Pakistan and Guatemala, the NMR remained almost unchanged over the period. The ≥ 2500 g risks related to maternal, delivery and newborn characteristics varied by site. Maternal factors that increased risk and were common for all sites included nulliparity, hypertensive disease, previous stillbirth, maternal death, obstructed labor, severe postpartum hemorrhage, and abnormal fetal presentation. Neonatal characteristics including resuscitation, hospitalization, congenital anomalies and male sex, as well as lower gestational ages and birthweights were also associated with increased mortality. Conclusions Nearly half of neonatal deaths in the Global Network sites occurred in infants born weighing ≥ 2500 g. The NMR for those infants was 13.1 per 1000 live births, much higher than rates usually seen in high-income countries. The changes in NMR over time varied across the sites. Even among babies born ≥ 2500 g, lower gestational age and birthweight were largely associated with increased risk of mortality. Since many of these deaths should be preventable, attention to preventing mortality in these infants should have an important impact on overall NMR. Trial registration: https://ClinicalTrials.gov Identifier: NCT01073475 | Neonatal deaths in infants born weighing ≥ 2500 g in low and middle-income countries | 10.1186/s12978-020-01013-7 |
2020-11-23 | R134a was recognized as probably one of the most important refrigerants of the two past decades. Among the proposed alternative fluids, there are certainly isobutane (R600a) and R152a. This article presents about 200 new heat transfer coefficient and pressure drop data obtained during flow boiling of R152a and R600a inside a smooth copper tube having an internal diameter of 4 mm. Three saturation temperatures were considered for each refrigerant, from 5 °C to 20 °C. Furthermore, for each temperature studied, the heat flux was varied between 15 and 30 kW m −2 and the refrigerant mass flux from 100 to 400 kg m −2 s −1 . After presenting the new data, a critical comparison was proposed between the performance of these refrigerants and R134a. Finally, some classic correlations available in the literature have been implemented. The deviations between the calculated and experimental values were reported and commented. | Flow boiling heat transfer capabilities of R134a low GWP substitutes inside a 4 mm id horizontal smooth tube: R600a and R152a | 10.1007/s00231-020-02991-x |
2020-11-23 | This study reports the performance analysis of an organic dye-sensitized solar cell (DSSC), introducing MnO 2 as an electron transport layer in TiO 2 /MnO 2 bilayer assembly. The DSSCs have been fabricated using TiO 2 and TiO 2 /MnO 2 layer-by-layer architecture films onto fluorine-doped tin oxide (FTO) glass and sensitized with natural dye extracted from Malvaviscus penduliflorus flower in ethanol medium. The counter electrode was prepared to layer copper powder containing paste onto FTO's conductive side by the doctor's blade method. The optical, morphological, and structural properties of photoanodes were explored via ultraviolet–visible, field emission scanning electron microscopy, and X-ray diffraction analyses. Moreover, dye complexity and thermostability of dyes were characterized via Fourier-transform infrared spectroscopy and thermogravimetric analyses. The iodide/triiodide (i.e., I − / I 3 − ) redox couple of electrolyte solution was employed as a charge transport medium between the electrodes. Finally, photoanode and counter electrode sandwiches were assembled to envisage the photovoltaic performance potential under simulated AM 1.5G solar illumination using 100 mW cm –2 light intensity. The as-fabricated DSSC comprising TiO 2 /MnO 2 bilayer assembly exhibited 6.02 mA cm –2 short circuit current density ( J sc ), 0.38 V open-circuit voltage ( V oc ), 40.38% fill factor, and 0.92% conversion efficiency, which is about 200% higher compared to the assembly devoid of MnO 2 layer. | Enhanced performance of dye-sensitized solar cell with thermally stable natural dye-assisted TiO2/MnO2 bilayer-assembled photoanode | 10.1007/s40243-020-00185-3 |
2020-11-23 | Background Although under-5 mortality has decreased in the last two decades, neonatal mortality remains a global health challenge. Despite achieving notable progress, Ethiopia has still one of the highest neonatal mortality rates worldwide. We aimed to assess the risk factors for mortality among neonates admitted to a special care unit in a referral hospital in rural Ethiopia. Methods This was a retrospective observational study including all 4182 neonates admitted to the special care unit of the St. Luke Wolisso Hospital (Ethiopia) from January 2014 to December 2017. Data were retrieved from hospital charts and entered in an anonymized dataset. A logistic regression model was applied to identify predictors of mortality and effect sizes were expressed as odds ratios with 95% confidence intervals. Results Proportion of deaths was 17% (709/4182 neonates). Neonates referred from other health facilities or home (odds ratio 1.52, 95% confidence interval 1.21 to 1.91), moderate hypothermia at admission (odds ratio 1.53, 95% confidence interval 1.09 to 2.15) and diagnosis of late-onset sepsis (odds ratio 1.63, 95% confidence interval 1.12 to 2.36), low birthweight (odds ratio 2.48, 95% confidence interval 2.00 to 3.09), very low birthweight (odds ratio 11.71, 95% confidence interval 8.63 to 15.94), extremely low birthweight (odds ratio 76.04, 95% confidence interval 28.54 to 263.82), intrapartum-related complications (odds ratio 4.69, 95% confidence interval 3.55 to 6.20), meconium aspiration syndrome (odds ratio 2.34, 95% confidence interval 1.15 to 4.43), respiratory distress (odds ratio 2.25, 95% confidence interval 1.72 to 2.95), other infections (odds ratio 1.92, 95% confidence interval 1.31 to 2.81) or malformations (odds ratio 2.32, 95% confidence interval 1.49 to 3.57) were associated with increased mortality. Being admitted in 2017 vs. 2014 (odds ratio 0.71, 95% confidence interval 0.52 to 0.97), and older age at admission (odds ratio 0.95, 95% confidence interval 0.93 to 0.97) were associated with decreased likelihood of mortality. Conclusions The majority of neonatal deaths was associated with preventable and treatable conditions. Education on neonatal resuscitation and postnatal management, and the introduction of an on-call doctor for high-risk deliveries might have contributed to the reduction in neonatal mortality over time. | Risk factors for mortality among neonates admitted to a special care unit in a low-resource setting | 10.1186/s12884-020-03429-2 |
2020-11-23 | Moroccan high-grade phosphate has so far always been upgraded by reverse flotation. Within a major project to go back to the deposits considered as sterile or low grade, this preliminary study was conducted in a micro-flotation cell to find new routes for their beneficiation by direct flotation. Three collectors, alone and combined to modifiers, were evaluated for a potential direct flotation of apatite from calcite and quartz minerals. The obtained results demonstrated that sodium oleate (NaOl) and ATRAC 50S have an affinity toward both apatite and calcite, but not quartz. In the opposite, Phospholan PE 169 has an affinity toward the three minerals even when it is combined with depressants. NaOl and ATRAC 50S flotation selectivity of apatite can be improved by their combination at dosages of 5.56 to 3.7 mg/L sodium alginate or CMC at pH 9.5. Apatite recovery exceeded 95%, and calcite buoyancy decreased from about 50% to only 19.20% and 19.39% using sodium alginate and CMC as prior depressants, respectively. On the other hand, when ethylene glycol was added as a synergist with the collector ATRAC 50S and sodium alginate as a depressant, 78.10% apatite recovery was obtained with 23.78% and 1.47% for calcite and quartz, respectively. These results were correlated to adsorption tests, zeta potential measurements, and FTIR analysis. | Direct flotation of low-grade Moroccan phosphate ores: a preliminary micro-flotation study to develop new beneficiation routes | 10.1007/s12517-020-06279-6 |
2020-11-23 | Masson pine ( Pinus massoniana ) is primarily present within subtropical and tropical areas in China, and a number of these regions have a severe deficiency in inorganic phosphate (Pi). As a macronutrient, phosphorus plays a crucial role in plant development. Although several studies have documented the responses of masson pine to Pi starvation at a global level using RNA-Seq and comparative proteomic analyses, the detailed features in the roots that primarily respond to low Pi stress have not yet been studied. Our study examined the response of masson pine roots to a deficiency in Pi. Approximately 1117 unigenes were shown to respond to Pi deficiency by differential expression when analyzed using RNA-Seq. A total of 819 and 298 of these transcripts were up- and down-regulated, respectively. Several transporters including phosphate transporters ( PHT1, PHO88 ), ABC transporters and metal transporters were identified. The ethylene response factor (ERF) was found to be the most abundant transcription factor. Analyses of these genes, including gene ontology enrichment and the KEGG pathway analysis, indicated that the metabolic processes are the most enriched under abiotic stresses, including Pi deficiency. This study provided abundant transcriptomic information to functionally dissect the response of masson pine roots to Pi deficiency. This will additionally aid to elucidate the biological regulatory mechanisms that the pines use to respond to low Pi stress. | Transcriptome analysis of low phosphate stress response in the roots of masson pine (Pinus massoniana) seedlings | 10.1007/s11738-020-03167-0 |
2020-11-23 | Background Epilepsy is characterized by the typical symptom of seizure, and anti-seizure medications are the main therapeutic method in clinical, but the effects of these therapy have not been satisfactory. To find a better treatment, it makes sense to further explore the regulatory mechanisms of seizures at genetic level. Lrp4 regionally expresses in mice hippocampus where is key to limbic epileptogenesis. It is well known that neurons release a high level of glutamate during seizures, and it has been reported that Lrp4 in astrocytes down-regulates glutamate released from neurons. However, it is still unclear whether there is a relationship between Lrp4 expression level and seizures, and whether Lrp4 plays a role in seizures. Results We found that seizures induced by pilocarpine decreased Lrp4 expression level and increased miR-351-5p expression level in mice hippocampus. Glutamate reduced Lrp4 expression and enhanced miR-351-5p expression in cultured hippocampal astrocytes, and these effects can be partially attenuated by AP5. Furthermore, miR-351-5p inhibitor lessened the reduction of Lrp4 expression in glutamate treated hippocampal astrocytes. Local reduction of Lrp4 in hippocampus by sh Lrp4 lentivirus injection in hippocampus increased the threshold of seizures in pilocarpine or pentylenetetrazol (PTZ) injected mice. Conclusions These results indicated that high released glutamate induced by seizures down-regulated astrocytic Lrp4 through increasing miR-351-5p in hippocampal astrocytes via activating astrocytic NMDA receptor, and locally reduction of Lrp4 in hippocampus increased the threshold of seizures. Lrp4 in hippocampal astrocytes appears to serve as a negative feedback factor in seizures. This provides a new potential therapeutic target for seizures regulation. | Lrp4 in hippocampal astrocytes serves as a negative feedback factor in seizures | 10.1186/s13578-020-00498-w |
2020-11-23 | Background Pre-eclampsia is a pregnancy complication characterised by high blood pressure and multi-organ dysfunction in the mother. It is a leading contributor to maternal and perinatal mortality, with 99% of these deaths occurring in low- and middle-income countries (LMIC). Whilst clear guidelines exist for management of early-onset (< 34 weeks) and term (≥ 37 weeks) disease, the optimal timing of delivery in pre-eclampsia between 34 + 0 and 36 + 6 weeks is less clear. In a high-income setting, delivery may improve maternal outcomes without detriment to the baby, but this intervention is yet to be evaluated in LMIC. Methods The CRADLE-4 Trial is a non-masked, randomised controlled trial comparing planned early delivery (initiation of delivery within 48 h of randomisation) with routine care (expectant management) in women with pre-eclampsia between 34 + 0 and 36 + 6 weeks’ gestation in India and Zambia. The primary objective is to establish whether a policy of planned early delivery can reduce adverse maternal outcomes, without increasing severe neonatal morbidity. Discussion The World Health Organization recommends delivery for all women with pre-eclampsia from 37 weeks onwards, based on evidence showing clear maternal benefit without increased neonatal risk. Before 34 weeks, watchful waiting is preferred, with delivery recommended only when there is severe maternal or fetal compromise, due to the neonatal risks associated with early preterm delivery. Currently, there is a lack of guidance for clinicians managing women with pre-eclampsia between 34 + 0 and 36 + 6 weeks. Early delivery benefits the mother but may increase the need for neonatal unit admission in the infant (albeit without serious morbidity at this gestation). On the other hand, waiting to deliver may increase the risk of stillbirth, fetal growth restriction and hypoxic brain injury in the neonate as a result of severe maternal complications. This is especially true for LMIC where there is a higher prevalence of adverse events. The balance of risks and benefits therefore needs to be carefully assessed before making firm recommendations. This is the first trial evaluating the optimal timing of delivery in pre-eclampsia in LMIC, where resources and disease burden are considerably different. Trial registration ISRCTN 10672137 . Registered on 28 November 2019. | Planned early delivery versus expectant management to reduce adverse pregnancy outcomes in pre-eclampsia in a low- and middle-income setting: study protocol for a randomised controlled trial (CRADLE-4 Trial) | 10.1186/s13063-020-04888-w |
2020-11-22 | This paper reports for the first time the possible formation of a novel room temperature therapeutic deep eutectic solvent (THEDES) of risperidone (RIS) with some fatty acids, namely capric acid (C10; CA), lauric acid (C12; LA), and myristic acid (C14; MA). All mixtures of RIS and MA yielded a solid or pasty-like solid and were readily discarded. Some of the prepared THEDESs from RIS and CA or LA have spontaneously transformed into a transparent liquid, without any precipitate at room temperature by simple physical mixing of the components. From the DSC thermograms, phase diagrams of the eutectic systems were constructed and the lowest obtained melting point for a RIS:CA mixture was 17°C at 40:60% w/w ratio. While 22°C was recorded as the lowest melting point for RIS:LA at a ratio of 30:70% w/w, solubility improvement of RIS was up to 70,000-fold compared with water. Freeze-drying microscopy provided valuable information regarding the phase change and transitions the drug undergoes as a function of temperature and it clarifies the interpretation of the DSC results and provides valuable evidence of drug crystals co-melting within the fatty acid base. The presence of natural fatty acid as one component of THEDES and the depression in the melting point significantly ( P < 0.05) enhanced RIS skin permeation. Rheological studies showed a viscosity temperature dependency of the DES and well fitted to the Arrhenius equation. Application of the obtained THEDES on the shaved skin of rats revealed the absence of any irritation or edema effects. | A Novel Eutectic-Based Transdermal Delivery System for Risperidone | 10.1208/s12249-020-01844-4 |
2020-11-21 | Cubic bismuth zinc niobate (c-BZN) thick films were fabricated on flexible platinum foils by electrophoretic deposition technique. The X-ray diffraction studies reveal that the films are under tensile stress. The permittivity of the c-BZN thick film sintered at 850 and 950°C, measured at an applied frequency of 1 MHz were 114 and 125, respectively. The corresponding values of dissipation factors were 0.004 and 0.0038. The films were also exhibiting voltage-dependent dielectric properties. The biaxial tensile stress, which is developed as a result of substrate constraints during the sintering, leads to significant change in the relaxation and dielectric characteristics of the films compared to that of ceramics. From this study, it is expected that large tensile stress in c-BZN thick films can bring down the dielectric loss and the variation of the dielectric permittivity with temperature, which will make them attractive, low loss and temperature stable applications. | Electrophoretic deposition of Bi1.5Zn1.0Nb1.5O7 thick films on metal foils for flexible electronic devices | 10.1007/s12034-020-02253-w |
2020-11-20 | Background Dietary patterns low in glycemic load are associated with reduced risk of cardiometabolic diseases. Improvements in serum lipid concentrations may play a role in these observed associations. Objective We investigated how dietary patterns differing in glycemic load affect clinical lipid panel measures and plasma lipidomics profiles. Methods In a crossover, controlled feeding study, 80 healthy participants (n = 40 men, n = 40 women), 18–45 y were randomized to receive low-glycemic load (LGL) or high glycemic load (HGL) diets for 28 days each with at least a 28-day washout period between controlled diets. Fasting plasma samples were collected at baseline and end of each diet period. Lipids on a clinical panel including total-, VLDL-, LDL-, and HDL-cholesterol and triglycerides were measured using an auto-analyzer. Lipidomics analysis using mass-spectrometry provided the concentrations of 863 species. Linear mixed models and lipid ontology enrichment analysis were implemented. Results Lipids from the clinical panel were not significantly different between diets. Univariate analysis showed that 67 species on the lipidomics panel, predominantly in the triacylglycerol class, were higher after the LGL diet compared to the HGL (FDR < 0.05). Three species with FA 17:0 were lower after LGL diet with enrichment analysis (FDR < 0.05). Conclusion In the context of controlled eucaloric diets with similar macronutrient distribution, these results suggest that there are relative shifts in lipid species, but the overall pool does not change. Further studies are needed to better understand in which compartment the different lipid species are transported in blood, and how these shifts are related to health outcomes. This trial was registered at clinicaltrials.gov as NCT00622661. | Plasma lipidomic profiles after a low and high glycemic load dietary pattern in a randomized controlled crossover feeding study | 10.1007/s11306-020-01746-3 |
2020-11-20 | Background Due to its unique arrangement, the deep and superficial fibers of the multifidus may have differential roles for maintaining spine stabilization and lumbar posture; the superficial multifidus is responsible for lumbar extension and the deep multifidus for intersegmental stability. In patients with chronic lumbar spine pathology, muscle activation patterns have been shown to be attenuated or delayed in the deep, but not superficial, multifidus. This has been interpreted as pain differentially influencing the deep region. However, it is unclear if degenerative changes affecting the composition and function of the multifidus differs between the superficial and deep regions, an alternative explanation for these electrophysiological changes. Therefore, the goal of this study was to investigate macrostructural and microstructural differences between the superficial and deep regions of the multifidus muscle in patients with lumbar spine pathology. Methods In 16 patients undergoing lumbar spinal surgery for degenerative conditions, multifidus biopsies were acquired at two distinct locations: 1) the most superficial portion of muscle adjacent to the spinous process and 2) approximately 1 cm lateral to the spinous process and deeper at the spinolaminar border of the affected vertebral level. Structural features related to muscle function were histologically compared between these superficial and deep regions, including tissue composition, fat fraction, fiber cross sectional area, fiber type, regeneration, degeneration, vascularity and inflammation. Results No significant differences in fat signal fraction, muscle area, fiber cross sectional area, muscle regeneration, muscle degeneration, or vascularization were found between the superficial and deep regions of the multifidus. Total collagen content between the two regions was the same. However, the superficial region of the multifidus was found to have less loose and more dense collagen than the deep region. Conclusions The results of our study did not support that the deep region of the multifidus is more degenerated in patients with lumbar spine pathology, as gross degenerative changes in muscle microstructure and macrostructure were the same in the superficial and deep regions of the multifidus. In these patients, the multifidus is not protected in order to maintain mobility and structural stability of the spine. | Regional differences between superficial and deep lumbar multifidus in patients with chronic lumbar spine pathology | 10.1186/s12891-020-03791-4 |
2020-11-17 | Resuspension of road dust contributes to air quality issues with resulting health impacts. Limited studies imply that porous pavements can initially mitigate PM 10 emissions by acting as a dust trap, but the abrasion wear generates road dust and thus accelerates the clogging processes. In addition, knowledge regarding the impact of pavement types on road dust load dynamics is limited. Road traffic noise can be mitigated using porous pavements, but the use of studded tyres increases the abrasion wear of the pavement as well as increasing the noise emission. Due to this durability problem, porous pavements are rarely used in the Nordic countries where, instead, dense pavements which are abrasion resistant are more common. Linköping municipality, in Sweden, constructed a porous pavement to mitigate road traffic noise. This led to the opportunity to investigate the temporal variation of the dust load dynamics and inherent size distributions over the winter and spring in comparison to those of an adjacent dense pavement. Results, when using the wet dust sampler (WDS) method, showed similar dust load dynamics for the dense and porous pavements. The results were also compared to previous studies using the same method on different dense pavements in Stockholm, Sweden. All locations showed a seasonal variation with higher dust loads during winter and early spring and declining loads towards summer. The size distributions were more complex for the wheel tracks at the porous pavement, having primarily properties of a mixture model compared to the simple size distributions for the dense pavement. On the other hand, the dust load and size distribution were more similar between the porous and dense pavements regarding loads and shapes, indicating a less pronounced but similar behaviour between the surfaces outside of the wheel tracks. | Temporal Variation of Road Dust Load and Its Size Distribution—a Comparative Study of a Porous and a Dense Pavement | 10.1007/s11270-020-04923-1 |
2020-11-17 | Objective Low back pain (LBP) is one of the most disabling and costly conditions worldwide. It remains unclear why many individuals experience persistent and recurrent symptoms after an acute episode whereas others do not. A longitudinal cohort study was established to address this problem. We aimed to; (1) evaluate whether promising and potentially modifiable biological, psychological, social and behavioural factors, along with their possible interactions, predict LBP outcome after an acute episode; (2) compare these factors between individuals with and without acute LBP; and (3) evaluate the time-course of changes in these factors from LBP onset. This paper outlines the methodology and compares baseline characteristics between acute LBP and control, and LBP participants with and without follow-up. Results 133 individuals with acute LBP and 74 pain-free individuals participated. Bio-psycho-social and behavioural measures were collected at baseline and 3-monthly for 12 months (LBP) or 3 months (control). Pain and disability were recorded fortnightly. Baseline characteristics were mostly similar between those who did and did not return for follow-up. Initial analyses of this cohort have revealed important insights into the pathways involved in acute-to-chronic LBP. These and future findings will provide new targets for treatment and prevention of persistent and recurrent LBP. | Cohort profile: why do people keep hurting their back? | 10.1186/s13104-020-05356-z |
2020-11-13 | Indigenous village chickens (IVCs) greatly contribute to food security and rural development. Consequently, IVCs cover incidental expenses, economically empower women, and support the livelihood of disadvantaged groups. Interestingly, ritual practices of traditional communities across the Global South utilise IVCs. IVCs provide several ecosystem services and possess adaptation traits resulting in their being able to survive and reproduce with minimal care. Explorative behaviours and general hardiness aroused from natural selection enable IVCs to adapt to a wide range of agroecology and management systems. IVCs are mainly kept in the extensive production system with scarce production inputs. Their management history and uncontrolled mating have enabled IVCs to have unique and diverse phenotypes. Flock size is small, typically less than 100, and the family flock consists of birds of both sexes and different ages making management a demanding task. IVCs lay few eggs (~ 40 to 60 annually) and have small body weights (~ 1.6 kg for adult cock) and low growth rates; nevertheless, they offer multiple as well as unique products and services. Productivity can be improved significantly with appropriate changes to management. There is a wealth of knowledge, wisdom, and practice associated with IVC production, which together with identified cost-effective interventions incorporating improvements in management, nutrition, disease control, and/or genetics have the potential to achieve profitable and sustainable production for the benefit of subsistence farmers and their families. | Indigenous village chicken production: a tool for poverty alleviation, the empowerment of women, and rural development | 10.1007/s11250-020-02433-0 |
2020-11-13 | Contourite deposits are recognized for the first time from the Lower Triassic Mirga Mir Formation in the Kurdistan region, Northern Iraq. The formation represents deposition on the southern passive margin of the Neo-Tethys during its early opening stages. The contourites are characterized by lenticular and sorted siltstones to fine-grained sandstones with current ripples, cross beddings and scour surfaces. These current structures are associated with thin-bedded (5–20 cm) limestones and shales. Petrographic investigations of the associated carbonate successions show both skeletal and non-skeletal grains such as peloids, ooids, intraclasts and extraclasts. Deposition occurred in a ramp setting at the southern passive margin of the Neo-Tethys and the skeletal grains reveal deep open marine and shallow warm water. Four different facies associations are recognized: Offshoal/basinal, foreshoal/slope, shoal and back shoal/lagoon. Field observations and thin section analysis revealed four main contourite facies in the studied outcrops, namely muddy contourites, silty contourites, sandy contourites and calcareous sandy contourites. The contourites are integrated with the basinal, offshoal, foreshoal and slope deposits. Stable isotope data from the carbonates of Mirga Mir Formation show that the δ 18 O (‰) values are negatives but the δ 13 C data shows negative and positive values. They show that had underwent meteoric diagenesis and that the δ 13 C values still preserving their primary depositional signal. The carbon isotopes data conforms to available data from the surrounding countries and by comparison with Early Triassic δ 13 C stratigraphic trends, it had captured at least two of the well-known positive spikes and at least one of the negative dips. Sequence stratigraphic analysis and stacking patterns revealed that the Mirga Mir Formation can be divided into two third-order depositional sequences. Each sequence is characterized by TST deposits followed by HST deposits and without LST. | The sedimentology and sequence stratigraphy of contourites and associated rocks at the northeastern passive margin of Gondwana during the Early Triassic (Induan - Mirga Mir Formation), Iraqi Kurdistan | 10.1007/s12517-020-06207-8 |
2020-11-12 | The combination therapy based on multifunctional nanocomposites has been considered as a promising approach to improve cancer therapeutic efficacy. Herein, we report targeted multi-functional poly( N -isopropylacrylamide) (PNIPAM)-based nanocomposites for synergistic chemo-photothermal therapy toward breast cancer cells. To increase the transition temperature, acrylic acid (AAc) was added in synthetic process of PNIPAM, showing that the intrinsic lower critical solution temperature was changed to 42 °C . To generate the photothermal effect under near-infrared (NIR) laser irradiation (808 nm), polypyrrole (ppy) nanoparticles were uniformly decorated in PNIPAM-AAc. Folic acid (FA), as a cancer targeting ligand, was successfully conjugated on the surplus carboxyl groups in PNIPAM network. The drug release of PNIPAM-ppy-FA nanocomposites was efficiently triggered in response to the temperature change by NIR laser irradiation. We also confirmed that PNIPAM-ppy-FA was internalized to MDA-MB-231 breast cancer cells by folate-receptor-mediated endocytosis and significantly enhanced cancer therapeutic efficacy with combination treatment of chemo-photothermal effects. Therefore, our work encourages further exploration of multi-functional nanocarrier agents for synergistic therapeutic approaches to different types of cancer cells. | Near-Infrared Light-Triggered Thermo-responsive Poly(N-Isopropylacrylamide)-Pyrrole Nanocomposites for Chemo-photothermal Cancer Therapy | 10.1186/s11671-020-03444-4 |
2020-11-12 | Background Work-related musculoskeletal disorders (WMSDs) represent an important socio-economic burden. The current risk assessment and management involved in the ethiopathogenesis of WMSDs is based on observational tools and checklists, which have some limitations in terms of accuracy and reliability. The aim of this study was to assess WMSD prevalence and identify possible correlations with several socio-demographic and work-related variables in a large cohort representative of Italian workers in order to improve our understanding of the WMSD phenomenon. Methods This study includes data from INSuLa, a cross-sectional nationally representative survey of health and safety at work, developed by the Italian Workers’ Compensation Authority. A total of 8000 Italian workers were included. Multivariate logistic regression analyses were performed to evaluate the association of independent variables, such as workers’ perceptions of exposure to biomechanical/ergonomic and video display unit (VDU) risks (Risk Perceived) and the actual risk exposure (Risk Detected) on Back, Lower and Upper limb pain. Socio-demographic, occupational and other health-related variables were included to investigate possible association with musculoskeletal disorders. Results Workers perceiving a significant exposure to biomechanical/ergonomic and VDU risks but not included in a health surveillance program for them (Risk Perceived/No Risk Detected) have had significantly higher odds of reporting musculoskeletal disorders. Regarding the biomechanical/ergonomic risk these workers are in the 19–24 age range (39.9%), transportation, warehousing/information and communication sectors (38.9%) and are employed in companies with more than 250 workers (35.8%). Regarding VDU risk, workers are in the 45–54 age range (24.5%), professional, financial and business services (38.0%) and come from companies with more than 250 employees (25.6%). Conclusions Within the occupational safety and health management systems an appropriate assessment of occupational risk factors correlated to musculoskeletal disorders (mainly biomechanical/ergonomic and VDU) and the correct definition of their exposure levels is essential to adequately prevent the onset of WMSDs. In this regard, our findings provide useful information to design novel approaches, aimed at improving our understanding of emerging risks, identifying gaps in current risk assessment strategies and enhancing workplace interventions are mandatory to improve the occupational risk assessment and management process and therefore implement the subsequent health surveillance systems. | Prevalence of work related musculoskeletal disorders in Italian workers: is there an underestimation of the related occupational risk factors? | 10.1186/s12891-020-03742-z |
2020-11-11 | The Grobgneis complex, located in the eastern Austroalpine unit of the Eastern Alps, exposes large volumes of pre-Alpine porphyric metagranites, sometimes associated with small gabbroic bodies. To better understand tectonic setting of the metagranites, we carried out detailed geochronological and geochemical investigations on the major part of the porphyric metagranites. LA–ICP–MS zircon U–Pb dating of three metagranites sampled from the Grobgneis complex provides the first reliable evidence for large volumes of Permian plutonism within the pre-Alpine basement of the Lower Austroalpine units. Concordant zircons from three samples yield ages at 272.2 ± 1.2 Ma, 268.6 ± 2.3 Ma and 267.6 ± 2.9 Ma interpreted to date the emplacement of the granite suite. In combination with published ages for other Permian Alpine magmatic bodies, the new U–Pb ages provide evidence of a temporally restricted period of plutonism (“Grobgneis”) in the Raabalpen basement Complex during the Middle Permian. Comparing the investigated basement with that of the West Carpathian basement, we argue that widespread Permian granite magmatism occurred in the Lower Austroalpine units. They belong to the high-K calc-alkaline to shoshonitic S-type series on the base of geochemical data. Zircon Hf isotopic compositions of the Grobgneis metagranites show ε Hf ( t ) values of − 4.37 to − 0.6, with T DM2 model ages of 1.31–1.55 Ga, indicating that their protoliths were derived by the recycling of older continental crust. We suggest that the Permian granitic and gabbroic rocks are considered as rifted-related rocks in the Lower Austroalpine units and are contemporaneous with cover sediments. | Widespread Permian granite magmatism in Lower Austroalpine units: significance for Permian rifting in the Eastern Alps | 10.1186/s00015-020-00371-5 |
2020-11-11 | Low-voltage-triggered silicon-controlled rectifier (LVTSCR) is expected to provide an electrostatic discharge (ESD) protection for a low-voltage integrated circuit. However, it is normally vulnerable to the latch-up effect due to its extremely low holding voltage. In this paper, a novel LVTSCR embedded with an extra p-type MOSFET called EP-LVTSCR has been proposed and verified in a 28-nm CMOS technology. The proposed device possesses a lower trigger voltage of ~ 6.2 V and a significantly higher holding voltage of ~ 5.5 V with only 23% degradation of the failure current under the transmission line pulse test. It is also shown that the EP-LVTSCR operates with a lower turn-on resistance of ~ 1.8 Ω as well as a reliable leakage current of ~ 1.8 nA measured at 3.63 V, making it suitable for ESD protections in 2.5 V/3.3 V CMOS processes. Moreover, the triggering mechanism and conduction characteristics of the proposed device were explored and demonstrated with TCAD simulation. | Robust and Latch-Up-Immune LVTSCR Device with an Embedded PMOSFET for ESD Protection in a 28-nm CMOS Process | 10.1186/s11671-020-03437-3 |
2020-11-06 | Pyrite from outcrops of Late Ordovician–Early Silurian marine shales of the Sichuan Basin was studied in the laboratory setting. We characterized various occurrences of pyrite using optical microscopy, reflected light microscopy, X-ray analysis, scanning electron microscopy, and energy-dispersive analysis, and image analysis to aid visual estimates of pyrite in polished sections. We observed two classes and four subclasses of pyrite in this marine shale depositional environment. A total of 2964 pyrite framboids and 16,393 pyrite monocrystal particles were measured, with an average particle size value from 2.57 to 6.24 μm in framboidal pyrite and from 0.32 to 0.61 μm in component monocrystals. Over 88% of framboidal pyrite particle size ranges from 1.5 to 9 μm, and the diameter between 0.2 and 0.8 μm is greater than 89% of total pyrite monocrystal particles. The cubic form of pyrite has particle sizes that range from 2.56 to 101.93 μm, more than 83% ranging from 5 to 30 μm. Image analysis of pyrite particle reveals dimensions between 1.0 and 7.5 μm and shape factors from 0.9 to 1.0 (nearly round), indicating that the primary pyrite type in marine shale formation is framboidal pyrite. The framboidal pyrite has important geological significance for marine shale formations. Size analysis, organic matter content, and stratigraphic distribution of framboidal pyrite reveal that the average particle size of framboidal pyrite varies according to deposition in either a dysoxic or a euxinic sedimentary environment. The Fe and S atomic content in framboidal pyrite is relatively low and correlates with high C atomic content, which suggests a close relationship between framboidal pyrite and organic matter. We identified six pore types in this study. Pores are developed in organic matter that occurs between framboidal monocrystals, as well as in organic matter that surrounds framboidal pyrite. Despite their small size, organic porosity remains conducive to the natural gas adsorption, and porosity associated with pyrite may also contain methane in the subsurface. | Statistical analysis and significance of pyrite in the Wufeng-Lower Longmaxi Shale Formation in South China | 10.1007/s12517-020-06190-0 |
2020-11-05 | Background Inflammatory response has been recognized as a pivotal pathophysiological process during cerebral ischemic stroke. NLRP3 inflammasome, involved in the regulation of inflammatory cascade, can simultaneously lead to GSDMD-executed pyroptosis in cerebral ischemia. Low-density lipoprotein receptor (LDLR), responsible for cholesterol uptake, was noted to exert potential anti-inflammatory bioactivities. Nevertheless, the role of LDLR in neuroinflammation mobilized by cerebral ischemia/reperfusion (I/R) has not been investigated. Methods Ischemic stroke mice model was accomplished by middle cerebral artery occlusion. Oxygen-glucose deprivation was employed after primary cortical neuron was extracted and cultured. A pharmacological inhibitor of NLRP3 (CY-09) was administered to suppress NLPR3 activation. Histological and biochemical analysis were performed to assess the neuronal death both in vitro and in vivo. In addition, neurological deficits and behavioral deterioration were evaluated in mice. Results The expression of LDLR was downregulated following cerebral I/R injury. Genetic knockout of Ldlr enhanced caspase-1-dependent cleavage of GSDMD and resulted in severe neuronal pyroptosis. LDLR deficiency contributed to excessive NLRP3-mediated maturation and release of IL-1β and IL-18 under in vitro and in vivo ischemic conditions. These influences ultimately led to aggravated neurological deficits and long-term cognitive dysfunction. Blockade of NLRP3 substantially retarded neuronal pyroptosis in Ldlr −/− mice and cultured Ldlr −/− neuron after experimental stroke. Conclusions These results demonstrated that LDLR modulates NLRP3-mediated neuronal pyroptosis and neuroinflammation following ischemic stroke. Our findings characterize a novel role for LDLR as a potential therapeutic target in neuroinflammatory responses to acute cerebral ischemic injury. | Low-density lipoprotein receptor (LDLR) regulates NLRP3-mediated neuronal pyroptosis following cerebral ischemia/reperfusion injury | 10.1186/s12974-020-01988-x |
2020-11-04 | The results of long-distance oil and gas pipeline failure analysis are important to the industry in order to maintain the reliability and safety of them. Seam welding in these pipes is done with good accuracy at place of work, while girth welding is carried out in the installation site and usually causes the main failure problem. Therefore, the most vulnerable and crucial part of these pipes is the girth welding. Investigating the fracture behavior of girth weld in high-pressure gas pipeline systems at low temperatures is important because these products are hazardous and may lead to explosion, leading to economic losses and environmental pollution. In the present study, the fracture behavior of girth-welded API 5L X65 natural gas transportation pipes was experimentally investigated at low temperatures. The fracture parameters were obtained using Arcan fixture in which all of the in-plane modes including pure tensile mode to pure shear mode can be created by altering the loading angle from 0° to 90°. Finite element analysis was also conducted by ABAQUS finite element software in order to determine geometrical coefficients which are required in calculating the fracture toughness. Results revealed that by decreasing the temperature and increasing the mode II loading contribution, the fracture toughness values were also decreased. | Fracture assessment of pipeline girth weld at low temperature | 10.1007/s40430-020-02696-6 |
2020-11-04 | Background The recent use of antenatal care (ANC) has steadily improved in low- and middle-income countries (LMIC), but postnatal care (PNC) has been widely underutilized. Most maternal and newborn deaths occur during the critical postnatal period, but PNC does not receive adequate attention or support, particularly in Sub-Saharan Africa. In Ghana, the majority of mothers attend four ANC assessments, but far fewer receive the four recommended PNC visits. This study sought to understand perceptions toward PNC counselling administered prior to discharge among both mothers and healthcare providers in the Greater Accra Region of Ghana. Methods Facility assessments were conducted among 13 health facilities to determine the number and type of deliveries, staffing, timing of discharge following delivery and the PNC schedule. Structured interviews were conducted for 172 mothers over four-months in facilities, which included one regional hospital, four district hospitals, and eight sub-district level hospitals. Additionally, healthcare providers from 12 of the 13 facilities were interviewed. Data were analyzed with Chi-square or students t-test, as appropriate, with p < 0.05 considered statistically significant. Results Ninety-nine percent of mothers received PNC instructions prior to hospital discharge, the majority of which were given in a group format. Mothers in the regional hospital were significantly more likely to have been informed about maternal danger signs but were less likely to know the PNC schedule than were mothers in district and sub-district facilities. No mother recalled more than four maternal or five newborn danger signs. Thirty-eight percent of facilities did not have PNC guidelines. Most patient and providers reported positive attitudes toward the level of PNC education, however, knowledge was inconsistent regarding the number and timing of PNC visits as well as other critical information. Only 23% of patients reported having a contact number to call for concerns. Conclusions Despite overall positive feelings toward PNC among Ghanaian mothers and providers, there are significant gaps in PNC education that must be addressed in order to recognize problems and to prevent serious complications. Improvements in pre-discharge PNC counseling should be provided in Ghana to give mothers and babies a better chance at survival in the critical postnatal period. | Postnatal care education in health facilities in Accra, Ghana: perspectives of mothers and providers | 10.1186/s12884-020-03365-1 |
2020-11-04 | The mechanical properties and permeability of shales after supercritical carbon dioxide (SC-CO 2 ) imbibition are vital to shale gas production and CO 2 sequestration in shale reservoirs. In this study, triaxial compressive strength tests, steady state permeability tests, and CT scanning tests are performed on shale samples with 30 days of SC-CO 2 imbibition. The results show that minerals dissolution and precipitation occur during SC-CO 2 imbibition. The porosity calculated by the digital core increases by 19.190%. The axial stresses of samples with or without SC-CO 2 imbibition increase with increasing confining pressure. When the confining pressure changes between 5 and 20 MPa, the reductions range from 6 to 13% for strength and from 11.26 to 16.47% for Young’s modulus, respectively. The strength of the samples with or without imbibition agrees well with the Mohr–Coulomb criterion. The values of cohesion and internal friction angles are very close which indicates that shale samples with SC-CO 2 imbibition can still refer to the failure criterion for samples without CO 2 imbibition. The permeability of the sample after SC-CO 2 imbibition increases exponentially with the increase in injection pressure and decreases exponentially with an increase of effective pressure. The permeability of the sample before and after imbibition is more sensitive to the change of pore pressure than confining pressure. SC-CO 2 imbibition enhances the increase of permeability. The ratio of the shale permeability after imbibition to that before imbibition varies from the minimum of 42 times to the maximum of 827 times. The reduction of strength and increasing of permeability are beneficial for shale gas recovery. | Hydro-mechanical properties of a low-clay shale with supercritical CO2 imbibition | 10.1007/s40948-020-00200-x |
2020-11-03 | The voltage level converters (LCs) are required to attain optimized power consumption by interfacing two or more supply voltage domains in Systems-on-Chip (SoC) applications. The voltage level-up conversion can be easily and effectively achieved by the use of buffer structures. Hence this article proposes two buffer-based LCs, namely transmission gate buffer level converter (TGBLC) and stacked PMOS buffer level converter (SPBLC), based on voltage stepping technique. The energy-efficient transmission gate (TG) and stacked PMOS (SP) structures are proposed to define voltage steps in the buffer and ensure a wider voltage conversion range with high speed. The LCs are implemented in 0.18 $$\mu $$ μ m technology and their performance metrics are verified using a Spectre circuit simulator. The simulation results show that TGBLC and SPBLC can convert a low input voltage of 600 and 550 mV to 1.8 V, respectively. For the target input voltage of 0.8 V with frequency of 1 MHz, the TGBLC and SPBLC exhibit an improved delay of 7.3 and 7.1 ns with an energy consumption of 9.66 and 6.66 pJ per transition, respectively. It is noted from the experimental results that the proposed LCs are suitable for applications where simplicity and energy efficiency/low power with a wider conversion range is preferred. | Wide-range energy-efficient buffer-based voltage level-up converters for multi-supply voltage systems | 10.1007/s12046-020-01506-y |
2020-11-01 | Abstract The study explores the effect of helical rolling on the low-temperature impact toughness of pearlitic steel 09G2S. Helical rolling in two modes was performed at T = 850°C in six passes through rolls of varied diameters with air cooling (mode I) and water quenching (mode II). The tensile σ–ε curves at room temperature are characterized by parabolic strain hardening, without any specific behavior of low-temperature impact toughness. The third mode of helical rolling was performed in the temperature range of 850–500°C, when pearlite partially transformed to bainite at low temperatures. The steel exhibited high impact toughness in this mode at low temperatures down to T = –70°C. Scanning tunneling and scanning electron microscopy revealed structural turbulence during impact toughness measurements in steel processed by mode III helical rolling. The structural turbulence is observed as the formation of isolated microvortices (islands) of plastic flow. Under impact loading, the isolated flows of structural transformation move in a rotational manner with the fulfillment of the law of conservation of angular momentum. The interaction of bainite with electron subbands, which are embedded in bainite to shield the excess positive charge in the interstitial sites of lattice curvature, breaks the interatomic bonds of bainite, leading to the formation of platelet packets, island structure, and curved bainite platelets. The steel processed in mode III shows a five-fold increase in fatigue life. | Structural Turbulence of Pearlitic Steel 09G2S at
Low-Temperature Impact Toughness | 10.1134/S1029959920060120 |
2020-11-01 | CFRC based on alumina hydraulic binders are similar with respect to hardening mechanism to low-cement refractory concretes (LCRC) and ultralow cement concretes (ULCRC). They are characterized by significant strengthening in the heat treatment temperature range 200 – 300°C and severe weakening in the range 600 – 1000°C. By introducing silica sols or microsilica into their composition it is possible not only to reduce or eliminate the weakening effect, but also to increase their strength after firing due to mullite formation. CFRC based on alumina binders have improved thermomechanical properties compared with LCRC. Comparative evaluation of CFRC based on hydraulic binders with other types of refractory concretes is provided. | Cement-Free Refractory Concretes. Part 5. Cement-Free Refractory Concretes Based on Hydraulic Alumina Binders | 10.1007/s11148-020-00489-x |
2020-11-01 | Abstract The paper presents the results of the long-term experiment on the solid-phase transformation of the Au–Pb metallic system which takes place at room and cryogenic temperatures. It is found that the solid-phase contact interactions between lead and gold lead to the formation of the Pb + AuPb 3 eutectoid. The mass transfer and the phase formation are due to the lead extrusion along the percolation channels that form as a result of the substructural destruction of gold. No reaction layer forms at the boundary of the contacting metals. The decomposition of the solid solutions based on intermetallics AuPb 3 occurs through the process of the destructurization of the material into nanoparticles, the displacement of impurity atoms from the bulk to the boundaries, the integration and ordering of separated components of the solid solution. The decomposition of the AuPb 3 intermetallic compound leads to the formation of AuPb 2 and the phases of variable compositions, and, then, pure components Au + Pb. The decomposition occurs through the stage of fast growth of lead crystals accompanying by the formation of loose gold nanoparticles that gradually take a faceting. The results of these studies can be useful for solution of problems of designing multicomponent metallic materials with an evolution prediction of their structure–phase transformations under the service conditions. | Solid-Phase Low-Temperature Evolution of the Binary Pb–Au System: Via Contact Interactions to Intermetallic Compounds, through the Destructurization to a New Multielemental State | 10.1134/S1063783420110256 |
2020-11-01 | Abstract The review analyzes and generalizes literary data and the authors’ results demonstrating the principal difference in plant responses to low-temperature treatments of two different types: (1) long-term constant chilling and (2) short-term daily cooling (temperature drop). The literature indicating the specificity of plant responses to temperature drops as related to their parameters (intensity, duration, and timing in a diurnal cycle) is discussed. Environmental effects on plant responses to temperature drops are also considered. Peculiarity of responses to temperature drops of the plants representing the groups different in their relation to temperature and light are analyzed. Physiological and biochemical mechanisms of plant responses to temperature drops are discussed. | Plant Responses to a Daily Short-term Temperature Drop: Phenomenology and Mechanisms | 10.1134/S1021443720060187 |
2020-11-01 | for saving energy and protecting the environment, natural gas has been widely used in internal combustion engines, which makes the study on the ignition characteristics of natural gas/diesel mixtures important. In this work, the effects of trace methane addition on the ignition delay of n-heptane/air mixtures are numerically studied using a detailed n-heptane mechanism under marine engine-like conditions. The simulations are carried out based on the software CHEMKIN-PRO 18.0 with a closed homogeneous reactor. Results show that the prolonged ignition delay times (IDs) of n-heptane/air mixtures are observed over the whole initial temperature range after methane is added, and the increment of IDs in the negative temperature coefficient (NTC) region is significantly higher than that in high temperature region. The sensitivity analysis indicates that both inhibition and promotion effects of important elementary reactions on n-heptane oxidation are weakened because of methane addition. However, the weakening influence on the promoting effect is more prominent. In addition, the inhibition effect of some elementary reactions that are related to the methane oxidation is enhanced. Thus, the IDs of n-heptane/air mixture are prolonged. The analyses of reaction rate of production (ROP) show that the both the production and consumption rates of key radicals decrease significantly in NTC region after methane is added, but it is negligible in the high temperature region. The study can extend the theoretical basis of ignition characteristics of methane/n-heptane blends under elevated temperatures and pressures. | Mechanism of Methane Addition Affects the Ignition Process of n-heptane under Dual Fuel Engine-Like Conditions | 10.1007/s11630-020-1260-z |
2020-11-01 | Abstract Impact flexure and indentation of metals is considered. A test bench for failure assessment is developed, for the example of steel 45 at low temperatures. In this method, acoustic emission pulses are classified; an artificial neural network is employed. The fractographic data for impact flexure correlate well with the results of pulse recognition. | Assessment of the Low-Temperature Strength of Metals by Indentation with Analysis of Acoustic Emission | 10.3103/S1068798X20110106 |
2020-11-01 | Abstract The paper studies the effect of the temperature of helical rolling, which creates nanoscale mesoscopic structural states in lattice curvature zones, on the low-temperature impact toughness of Ti–6Al–4V alloy. The polymorphic transformation temperature T с = 950°C is shown to play the decisive role in this effect. The impact toughness is very high at helical rolling temperatures above T с , while in the low-temperature range up to T = –70°C it decreases monotonically. This is a very important aspect of the technology. Starting from the helical rolling temperature T = 950°C, the toughness sharply decreases at T = –70°C. At T = 900°C, it decreases sharply already at T = –20°C. At T = 850°C, the level of the entire toughness curve of the alloy is low. The high level of impact toughness at T > T с is found to be due to a two-stage transformation of the bcc β phase into a mixture of (α + β) phases. The first stage involves nonequilibrium microscopic decomposition into the α and β phases. At the second stage, the nonequilibrium β phase decomposes into (α + β) subbands in accordance with the interstitial structural states associated with lattice curvature. In helical rolling at T < T с , the formation of martensite phases in the close-packed lattice of the α phase of titanium reduces its impact toughness. The fatigue life of Ti–6Al–4V alloy helically rolled at T = 1000°C remains unchanged. | The Effect of Nanoscale Mesoscopic Structural States Associated
with Lattice Curvature on the Mechanical Behavior of Ti–6Al–4V
Alloy | 10.1134/S1029959920060016 |
2020-11-01 | An investigation has been conducted into the action of nonequilibrium low-temperature plasma of a high-frequency capacitive discharge in air at a pressure of 133.3 MPa upon the structure of brass and beryllium bronze. The absence of changes in the microstructure of alloys under the action of plasma was established using the target metallography method. It has been shown that the main effect of the plasma action is the formation of static distortions of the abovementioned materials at the level ~0.007·10 –10 m. | Variation in the Stress State of Copper Alloys Under the Action of Cold Air Plasma | 10.1007/s10891-020-02263-9 |
2020-11-01 | Silicon (Si) is an aussichtsreich anode candidate for a new generation lithium-ion batteries on account of its enormous theoretical capacity. However, its progress is tremendously hindered due to the tremendous volumetric change causes structure instability and poor cycling stability during the charge/discharge cycle. To overcome these issues associated with Si anodes, fabricated Si/C composites have been extensively studied. Here, this paper exploits a method for preparing a Si/C composite at low temperature and under atmospheric conditions, which has a graphite-C layer embedded with nanosilver particles. Carboxyl-rich alginate as a carbon source which silicon-carbon was tightly bound due to forms strong bonds (hydrogen bond) on the silicon surface. Tiny silver ions (0.01 M) were added to improve carbon stability by enhancing the cross-linking of alginate coated on the surface of large size micro silicon powder. The Si/Ag@C ternary composites were obtained, which combined simultaneous synthesis of nanosilver and crack-free graphite-C by subsequent low-temperature carbonization at 480 °C. Si/Ag@C exhibits high conductivity and long period recycle stability due to inducing high conductivity of nanosilver and crack-free graphite-C as anodes for LIBs. Si/Ag@C shows a well reversible capacity (724 mAh/g) over 100 cycles at 200 mA/g, which is more than thirty times that of Si (21 mAh/g). Si/Ag@C shows low electrochemical impedance and satisfactory rate capability due to its special structure. | A Nanosilver Embedded Graphite-C Shell Coating on Large Size Micro Silicon Formed by Low Temperature Carbonizing with Ag+ Increased the Cross-Linking of Alginate as an Anode for LIBs | 10.1007/s12633-019-00365-5 |
2020-11-01 | A novel route is developed for regeneration of deactivated commercial NH 3 -SCR catalysts, which includes an initial in situ construction of anatase TiO 2 porous film, followed by loading of MnO x , CeO x , and Mn-Ce mixed oxides as active components. The regenerated catalysts present largely improved low-temperature denitrification performance due to the synergetic effect of MnO x and CeO x . The denitrification efficiency could reach a high value of 97% at 200 °C and 100% at 250 °C when the Ce-Mn mixed oxides are loaded at the optimized molar quantity ratio of 10:9 (Ce:Mn). Properties and reaction mechanisms of the regenerated catalysts are investigated with characterizations of X-ray photoelectron spectroscopy (XPS), NH 3 temperature-programmed desorption (NH 3 -TPD), H 2 temperature-programmed reduction (H 2 -TPR), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Our results demonstrate that the adsorption and oxidation of NO plays a crucial role for these three catalysts even though a difference exists on the reaction pathways. Graphical abstract | A novel regeneration method for deactivated commercial NH3-SCR catalysts with promoted low-temperature activities | 10.1007/s11356-020-10086-7 |
2020-11-01 | Abstract Maximum solid solubility is a key parameter for nuclear waste immobilization. In this study, the maximum solid solubility of AgI in B 2 O 3 –Bi 2 O 3 –ZnO based materials has been investigated at 500, 550, and 600 °C. XRD results show that maximum solid solubility of AgI is 1.97 wt% (iodine content is 1.1 wt%). Amorphous fraction results increase with the increasing temperatures. Porosity results reflect that the sample with a higher amorphous fraction shows a lower porosity. Under the maximum solid solubility, Ag and I elements are distributed homogeneously. This study demonstrates the ability of B 2 O 3 –Bi 2 O 3 –ZnO based materials to immobilize iodine waste forms. Graphic abstract | Immobilization of iodine waste in B2O3–Bi2O3–ZnO based materials: maximum solid solubility | 10.1007/s10967-020-07428-7 |
2020-11-01 | Catalytic desulfurization is favored for its ability to desulfurize low concentrations of SO 2 by generating sulfur without the need for flue gas conditioning or additives. Maintaining reaction efficiency at a low temperature would justify the industrial scale use of this method. To that end, in this study, we modified a previously reported highly efficient CuO-ZrSnO 4 catalyst and investigated its desulfurization performance. The non-thermal plasma (NTP) method was used to enhance the low-temperature efficiency of the catalyst. The desulfurization rate was significantly improved without generating excess heat or by-products in the low-output mode of post-plasma-catalysis-type (PPC-type) dielectric barrier discharge (DBD). In addition, we studied the physicochemical properties of the catalyst (pore structure, physical structure, morphology, electronic properties, and chemical state) under plasma enhancement conditions. The catalyst loaded with 20 wt% Cu and aged at 40 °C exhibited optimum desulfurization performance. This study provides a theoretical foundation for the analysis of plasma-enhanced catalytic desulfurization under low-temperature conditions. Graphical abstract | Non-thermal plasma-enhanced low-temperature catalytic desulfurization of electrolytic aluminum flue gas by CuO-ZrSnO4: experimental and numerical analysis | 10.1007/s11356-020-09602-6 |
2020-11-01 | Cold atmospheric pressure plasma treatment is currently being explored as an alternative way to improve the germination and growing parameters of plant seeds. However, it is important to pay attention to the effect of plasma treatment on DNA damage of the seeds as well as detailed characteristics of plasma composition and parameters. The aim of this work was to study the DNA damage of plasma-treated pea seeds ( Pisum sativum L.) and plasma parameters such as the chemical composition of plasma gaseous compounds and plasma radiation. Seeds were treated with plasma using the diffuse coplanar surface barrier discharge generated in different working gases (ambient air, nitrogen, oxygen and different mixtures of oxygen and nitrogen) at atmospheric pressure and at 60 s, 180 s and 300 s exposure times. DNA damage was studied using the single cell-gel electrophoresis called the comet assay and the plasma parameters were investigated by Fourier transform infrared spectroscopy and optical emission spectroscopy. Experiments in different ratios of oxygen and nitrogen were realized in order to understand the reaction mechanism between the ambient air plasma and the treated seeds. Based on our results, ambient air plasma appears to be the most advantageous for the plasma treatment due to no significant DNA damage because of the proper combination of plasma composition in combination with water vapor present in ambient air. | Influence of Cold Atmospheric Pressure Plasma on Pea Seeds: DNA Damage of Seedlings and Optical Diagnostics of Plasma | 10.1007/s11090-020-10109-8 |
2020-11-01 | We present a two-dimensional tungsten disulfide (WS 2 )-based material as a reinforcement additive to produce thermally stable, mechanically strong, and light-weight epoxy (EP) composites. An aqueous melamine solution was used to exfoliate the bulk WS 2 into nanosheets while simultaneously functionalizing them to obtain melamine-functionalized WS 2 (N-WS 2 ) nanosheets. These non-covalently functionalized N-WS 2 nanosheets were used as toughening agents for epoxy composites. The contents of the N-WS 2 nanosheets were maintained at below 1 wt%. The effect of functionalization on the interfacial properties of EP composites was investigated in terms of the interfacial interactions between the EP and the nanosheets. The results demonstrated that the surface free energy of EP composites increased significantly after the incorporation of N-WS 2 nanosheets into the EP matrix and further increased with the increased loading of N-WS nanosheets up to a maximal value of 54.38 mJ-m 2 for the composite containing 0.18 wt% N-WS 2 nanosheets, suggesting a stronger interfacial interaction between the EP and N-WS 2 nanosheets. A gradual decrease in the surface free energy of the EP composites was observed at higher loadings, which might be attributed to the aggregation of N-WS 2 nanosheets within the matrix or excessive bonding of the sheets with one another rather than with the EP matrix due to their larger Van der Waals forces and their large surface area. The mechanical properties of the EP composites were analyzed and demonstrated 55%, 101%, 44%, and 15% improvements in the fracture toughness, fracture energy, flexural strength, and flexural modulus, respectively, for the composite containing 0.18 wt% N-WS 2 nanosheets. Moreover, the composites displayed increased glass transition temperatures and better thermal stabilities. | Effective Reinforcement of Melamine-functionalized WS2 Nanosheets in Epoxy Nanocomposites at Low Loading via Enhanced Interfacial Interaction | 10.1007/s13233-020-8151-8 |
2020-11-01 | This article discusses the structure of 15Kh2MFA steel at various segments of welded joint without thermal treatment using low-carbon surfacing. Three areas are highlighted in the low-carbon surfacing differing in the content of chemical elements transferring from the base metal to the surfacing one as well as in the propensity to form quenching structures during welding. Procedures making it possible to increase the strength of structural welding joints have been developed. | Structure of Welded Joints of 15Kh2MFA Steel with Low Carbon Surfacing without Thermal Treatment | 10.1134/S2075113320060271 |
2020-11-01 | When lithium-ion batteries (LIBs) are located at high altitude and low pressure,the characteristics of thermal runaway (TR) and its propagation are different,such as time to TR, the toxicity of TR gases, TR propagation time, mass loss rate, etc. In this article, the author summarized a series of relevant literatures and proposed an instrument that can be used to analyse the TR behavior at different pressure. It is found that: with the decrease of ambient pressure, the TR trigger time becomes longer and the maximum surface temperature decrease. Moreover, the gas released by TR becomes more toxic as the environmental pressure decreases. Beside, the average propagation time between adjacent LIBs is not much difference when the environmental pressure decreases, and when the 18,650 battery module is distributed in a cylindrical shape, the thermal runaway propagation path is basically unchanged as the environmental pressure decreases. This work details TR and its propagation feature under different pressure, and can provide the guidelines for the Air transportation of LIBs. | Study on the Thermal Runaway and Its Propagation of Lithium-Ion Batteries Under Low Pressure | 10.1007/s10694-020-00963-5 |
2020-11-01 | Abstract The existence of taste and odour (T&O) in drinking water is one of the principal causes of consumer complaints and is commonly related to algae growth. Numerous studies have confirmed the existence of algal blooms emerging specifically in low-temperature periods, herein referred to as “cold algae”; these include chrysophytes, cryptophytes, dinoflagellates and diatoms. In addition, the adaption mechanisms of these “cold algae” involve high flexibility in their nutrient intake and to the hydrological characteristics of the waters and their high contents of intracellular polyunsaturated fatty acids (PUFAs). Like algae proliferating in higher temperature waters, cold algae can also produce offensive odours. The potential dominant T&O compounds of low-temperature algae probably include saturated/unsaturated aldehydes and even some terpenoids. Among these, the polyunsaturated aldehydes (PUAs), the derivatives of polyunsaturated fatty acids, are the dominant T&O compounds and are probably synthesized during cell rupture. It was found that, for cold algae, low temperature may have a favourable effect on the generation of algae-induced T&O compounds. Furthermore, to better understand the internal mechanisms of algal T&O production, the stress response theory is introduced, which provides ideas for T&O control in raw water and in water treatment. Finally, implications for T&O management are given based on this review. Key points • Like algae proliferating in higher temperature waters, cold algae can produce offensive odours . • Low temperatures may have a favourable effect on the generation of algae-induced T&O compounds . • The stress response theory can help to better understand the internal mechanisms of algal T&O production . | Algae-induced taste and odour problems at low temperatures and the cold stress response hypothesis | 10.1007/s00253-020-10884-6 |
2020-11-01 | This study focuses on the microstructure and mechanical properties of the joints of Q235 mild steel, which was formed by the friction stir welding (FSW). The results indicated that, after the FSW, the heat-affected zone (HAZ) of the retreating side (HAZ RS ) and the HAZ of the advancing side (HAZ AS ) recovered under the influence of the heating cycle. The transformation of the phases in the thermo-mechanically affected zone (TMAZ) of the retreating side (TMAZ RS ), the stir zone (SZ) and the TMAZ of the advancing side (TMAZ AS ) generated the pearlite and acicular ferrite. The continuous dynamic recrystallization occurred in all the three zones, whereas the grains were refined. The SZ mainly consisted of D 1 , D 2 and F shear textures, while the TMAZ AS was made up of only the F shear texture. The fine-grained structure, pearlite and the acicular ferrite improved the hardness and tensile strength of the joint. Its ultimate tensile strength was 479 MPa, which was 1.3% higher than that of the base metal. However, the uniform elongation was 16%, which showed a decrease of 33%. The fracture was a ductile fracture with the appearance of dimples. Besides, the joints of the FSW showed an excellent bending performance. | Microstructure and Mechanical Properties of Low-Carbon Q235 Steel Welded Using Friction Stir Welding | 10.1007/s40195-020-01125-w |
2020-11-01 | The kinetics of hydrogenation of acrylonitrile butadiene rubber (NBR) latex by the action of diimide generated by hydrazine hydrate and hydrogen peroxide in the presence of copper sulfate at low temperature was studied by calculating the initial reaction rate constants. Altering reaction parameters of different reactant dosages such as carbon-carbon double bonds, hydrazine hydrate, hydrogen peroxide, and copper sulfate can be designed to calculate the initial reaction rate constant in a hydrazine hydrate/hydrogen peroxide/copper sulfate reaction system. The method of initial reaction rate constants gives rate constant and reaction order in the hydrogenation reaction of NBR latex calculated from the hydrogenation kinetic data. Based on these kinetic values, the kinetic equation of hydrogenation of NBR latex in this catalytic system at the temperature ranged from 5 to 65 °C and the hydrogenated reaction activation energy were studied in this paper. Graphical abstract | Kinetics of hydrogenation of acrylonitrile butadiene rubber: a latex-based in situ and low-temperature approach | 10.1007/s00396-020-04719-z |
2020-11-01 | Open-graded friction course (OGFC) asphalt mixture, usually used to construct porous pavements, represents one of the materials supporting low-impact development (LID) philosophy due to its use of coarse aggregate gradation. Using such mixtures brings several benefits related to safety, environment and economy. Alas, coarse, open-graded skeleton of OGFC mixtures is prone to failure, particularly raveling and stripping. Continuous traffic loading and the environmental impacts give hand in hand to further increase the potential for failure, hence higher pavement maintenance and rehabilitation costs. Application of different types of modifiers has proved effective in mitigating failure potential. The most common modifiers are polymers, fibers and anti-stripping agents. Aiming at minimizing the costs and maximizing the lifespan while considering sustainability, the study was to investigate the effect of using a recycled stabilizing material as an asphalt modifier on the performance of OGFC asphalt mixtures. Recycled Low-Density Polyethylene (R-LDP) was adopted in this investigation. Changes in mixture air void, porosity, draindown, permeability, rut depth, moisture damage and abrasion loss were observed to evaluate the effect. Compared with unmodified asphalt samples, R-LDP modification increased mixture air void, porosity and permeability by 15%, 10% and at least 40%, respectively. Also, it noticeably contributed to reducing rut depth, moisture damage and abrasion loss (both unaged and aged) by 31%, 20% and at least 40%, respectively. More significantly, it almost eliminated the draindown problem. Incorporating R-LDP proved effective in upgrading OGFC mixture properties to an acceptable level required by most specifications. | Durability assessment of open-graded friction course using a sustainable polymer | 10.1007/s42947-020-6013-6 |
2020-11-01 | The Ossa-Morena Zone (OMZ) has a complex geological history including both Cadomian and Variscan orogenic events. Therefore, the OMZ plays an important role in understanding the geodynamic evolution of Iberia. However, the P–T–t evolution of the OMZ is poorly documented. Here, we combine structural and metamorphic analyses with new geochronological data and geochemical analyses of mafic bodies in Ediacaran metasediments (in Iberia known as Série Negra) to constrain the geodynamic evolution of the OMZ. In the studied mafic rocks, two metamorphic stages were obtained by phase equilibria modelling: (1) a high-pressure/low-temperature event of 1.0 ± 0.1 GPa and 470–510 °C, and (2) a medium-pressure/higher-temperature event of 0.6 ± 0.2 GPa and 550–600 °C. The increase in metamorphic temperature is attributed to the intrusion of the Beja Igneous Complex (around 350 Ma) and/or the Évora Massif (around 318 Ma). New U–Pb dating on zircons from the mafic rocks with tholeiitic affinity yields an age between 815 and 790 Ma. If the zircons crystallised from the tholeiitic magma, their age would set a minimum age for the pre-Cadomian basement. The ca. 800 Ma protolith age of HP-LT tholeiitic dykes with a different metamorphic history than the host Série Negra lead us to conclude that: (1) the HP-LT mafic rocks and HP-LT marbles with dykes were included in the Ediacaran metasediments as olistoliths; (2) the blueschist metamorphism is older than 550 Ma (between ca. 790 Ma and ca. 550 Ma, e.g., Cadomian). | U–Pb zircon geochronology and phase equilibria modelling of HP-LT rocks in the Ossa-Morena Zone, Portugal | 10.1007/s00531-020-01921-w |
2020-11-01 | The sub-200 cm −1 (sub-6 THz) vibrations of molecular crystals provide identifying features that are characteristic of each solid sample under study. These distinctive vibrational spectra have driven the development of new techniques and instrumentation in analytical spectroscopy. As terahertz time-domain spectroscopy and low-frequency Raman spectroscopy become increasingly prevalent in non-specialist laboratories, the need for a common set of spectral standards for use across these techniques becomes imperative. To meet this need, α-lactose monohydrate, biotin, and L-cystine are proposed here as molecular standards to evaluate instrument performance with both terahertz and Raman spectroscopies, as well serve as benchmarks for quantum mechanical simulations and analyses of these spectra. These substances all reveal a series of readily discernable peaks across the low-frequency region and also over a range of temperatures (295–50 K) making them even more useful. The often overlooked aspect of detailed spectral interpretation and assignment is directly addressed with rigorous solid-state density functional theory simulations of the three compounds based on a standard computational framework. By investigating these proposed molecular crystal standards with commonly available experimental and theoretical approaches, a set of realistic performance expectations can be achieved for both commercial instrumentation and software being used in low-frequency vibrational spectroscopy. | Crystalline Molecular Standards for Low-Frequency Vibrational Spectroscopies | 10.1007/s10762-020-00725-y |
2020-11-01 | Abstract— The modern state of the processes connected with design, calculation, and operation of heaters used in steam turbine regeneration systems is reviewed and analyzed on the basis of data available from domestically published and foreign sources. The existing methods for thermal–hydraulic, strength, and vibration design calculations of apparatuses are described; criteria adopted in designing individual areas of heater heat-transfer surfaces are mentioned, and recommendations on taking into account the heat-transfer surface fouling in analyzing its influence on the apparatus’s thermal-efficiency indicators are given. The possibility of using modern computation tools for designing regeneration system apparatuses is considered. A list of materials from which the apparatus heat-transfer surface tubes are made is given; methods for fixing them in shell-and-tube heaters are mentioned, and the level of stresses recommended for individual tube sections is pointed out. The values of key operating parameters—coolant temperatures, pressures and velocities—are given, which are selected based on the results of designing the apparatuses and with reference to foreign standards and other regulatory documents. Recommendations used by foreign manufacturers of heaters as guidelines for selecting vibration-safe length of free spans and tube fastening methods in the bend zone are given. Failures that most frequently occur during operation of high- and low-pressure heaters are pointed out. Some questions concerned with the technology for repairing the regeneration system heaters used as part of a turbine plant are considered. It is shown that there are differences in arranging the repair system and, especially, in the maintenance of heat-transfer apparatuses as concerns the tools necessary for monitoring the equipment condition. The introduction of new technologies for designing and operating heaters in domestic practice will help keep their efficiency and reliability indicators at a high level. | State of the Art and Trends in the Design and Operation of High- and Low-Pressure Heaters for Steam Turbines at Thermal and Nuclear Power Plants in Russia and Abroad: Part 2. Heater Design and Operation Peculiarities | 10.1134/S0040601520110038 |
2020-11-01 | A graphene-based flexible filter was obtained via one-step laser heating of a polyimide film. The key parameters of a laser have been confirmed by comparing simulated results and experimental data. High-frequency components of input signals were filtered out effectively for different waveforms, such as sine, rectangular, triangle and pulse waveforms. In order to study filtering performance, this paper focused on amplitude frequency curve, phase frequency curve, transient response and mechanical stability. The phase frequency curve is linear distribution, indicating that it is convenient to control phase shift. The mechanical stability of the device remains good even after 5000 bends, which is unreported in previous work. This paper demonstrated that a graphene-based flexible filter prepared by one-step laser heating has excellent performance and opens new way of thinking about flexible electronics in the future. | A Flexible Low-Pass Filter Based on Laser-Induced Graphene | 10.1007/s11664-020-08462-7 |
2020-11-01 | Abstract Despite cold stress is a critical environmental condition that influences the growth and development of bell pepper ( Capsicum annuum L.), the underlying molecular mechanism remains unclear. This study aimed to explore the genes associated with the low temperature stress response in bell pepper. Bell pepper ‘Zhongjiao NO.4’ (CRC, cold resistance cultivar) and ‘Zhong 30’ (WT, cold sensitive variety) was used in this study. CRC was grown under 4°C for 0 h (Low), 8 h (Low 8), 16 h (Low 16), and 24 h (Low 24), as well as WT was also grown under 4°C. The transcriptome profile of bell pepper was obtained through Illumina RNA-sequencing. The differentially expressed genes (DEGs) between Low and WT groups were explored, and DEGs between every two groups of Low, Low8, Low16, and Low24 were also screened. Time series clustering analysis of DEGs among Low groups was performed. Functional enrichment analysis of DEGs was conducted by using cluster Profiler package, followed by protein-protein interaction (PPI) analysis. The results showed that DEGs in CRC were involved in flavonoid biosynthesis and phenylalanine metabolism. Functional enrichment analysis of time-course related DEGs indicated that genes were mainly associated with metabolic process, photosynthesis, and lipid metabolic process. LOC107864131 , LOC107857080 , and LOC107855212 were considered as hub genes, and played vital role in cold stress in bell pepper. Meanwhile, the expression level of ribosomal proteins-related genes was significantly down-regulated during cold treatment. The dynamic expression changes revealed the regulatory role of genes in cold stress response of bell pepper. Our findings might shed light on the molecular mechanisms related to cold tolerance in bell pepper and provide useful candidate genes for genetic improvement. | Transcriptome Analysis Reveals Candidate Genes Involved in Low Temperature Stress in Bell Pepper | 10.1134/S1021443720060084 |
2020-11-01 | Abstract It is shown that when exposed to low-temperature atmospheric pressure plasma (LTAPP) on a single-cell culture of Paramecium caudatum as a result of changes in the external conditions (ionic composition of the solution), the nature of the movement changes and the number of viable cells decreases. The viability of Paramecium caudatum cells depends on the time of exposure to the plasma and is correlated with the changes in the pH of the medium. The kinetic features of the processes discovered in the work are analyzed: the aftereffect of exposure to the plasma and the stepwise nature of the cells’ death. | Influence of a Medium’s pH on Paramecium caudatum Cells under Exposure to the Low Temperature Atmospheric Pressure Plasma | 10.1134/S1990793120060202 |
2020-11-01 | The Louisiana Department of Transportation and Development (DOTD) and other state agencies are continuously looking for techniques to reduce roadway maintenance and construction costs. A common consideration is to introduce asphalt mixtures with a smaller nominal maximum aggregate size (NMAS) for utilization in roadways. In a previous study, DOTD concluded that mixtures with a 4.75 mm NMAS provided acceptable performance as a surface layer. Excessive stockpiles of unused smaller aggregates can result in an economically competitive source to be consi dered for asphalt mixtures. The DOTD developed mixtures with four aggregate types and two binder types. A comprehensive evaluation of performance was conducted through volumetric and mechanistic testing. Performance testing consisted of the Loaded Wheel Tracking (LWT) test to determine rutting resistance, Semi-Circular Bend (SCB) test to evaluate intermediate temperature cracking resistance, and dynamic modulus (E*) to ascertain the stiffness at intermediate temperatures. As expected, asphalt binder grade, aggregate type and mixture composition affected the performance of mixtures evaluated. Gravel mixtures were susceptible to cracking, while limestone mixtures were susceptible to rutting. An economic analysis was conducted to determine the viability of 4.75 mm mixtures. The cost per ton of 4.75 mm mixtures in Louisiana was higher than conventional 12.5 mm mixtures. However, when considering the lift thickness of potential overlays, the 4.75 mm aggregate mixtures became more viable. Further, a life-cycle analysis of a designed pavement using AASHTO Pavement-ME was performed to compare the lifetime durability of the 4.75 mm NMAS mixtures to a conventional 12.5 mm mixture. | Development of a 4.75 mm asphalt mixture design for Implementation in Louisiana DOTD Specifications | 10.1007/s42947-020-6014-5 |
2020-11-01 | For nano-porous anodized aluminum oxide (AAO) template based low temperature solid oxide fuel cells (LT-SOFCs), anode structure has crucial effects on electrochemical characteristics because of triple phase boundary densities and electrical connectivity of metal catalysts on porous AAO substrates. In this study, we investigated effects of fabrication processes of Ni anode for AAO template based LT-SOFCs. Ni anodes were prepared at various deposition pressure, i.e. low pressure, high pressure and low pressure–high pressure, on nano-porous AAO substrates by physical vapor deposition. Surface morphology and cross-sectional structure of various Ni anodes were systematically evaluated. Electrochemical characterizations of LT-SOFCs with various anode structures were successfully conducted at 500 °C. The Ni anode prepared at low pressure showed high electrical conductivity and low catalytic activity. However, Ni anode which was fabricated at high pressure exhibited poor electrical conductivity and good catalytic activity. Bilayer Ni anode which was deposited in sequence at low pressure and high pressure presented both good electrical conductivity and good catalytic activity. The LT-SOFC with the bilayer Ni anode cell achieved the best performance, 201 mW/cm 2 at 500 °C. Electrochemical impedance spectroscopy analysis was conducted to reveal detailed behaviors of AAO based LT-SOFCs. Therefore, we successfully optimized the anode structure for high performance AAO template based LT-SOFCs. | Effects of Microstructure of Ni Anode on Nanotemplate Based Low Temperature Solid Oxide Fuel Cells | 10.1007/s12541-019-00307-6 |
2020-11-01 | Results are provided for a study of the effect of different microalloying systems (Nb, Nb–V, V–N) on structure formation and mechanical properties of rolled product of strength class K52 produced by combined technology of melting, casting of thin slabs 90 mm thick, and direct rolling with subsequent accelerated cooling and winding on a coil. It is shown that all of the micro-alloying versions selected provide the required strength properties, while metal microalloyed solely with niobium demonstrates the best brittle fracture resistance at low temperature. It is shown that addition of niobium to steel not only refines grain size in the metal matrix, but also changes ferrite morphology increasing the proportion of acicular ferrite, which improves steel cold resistance. | Study of the Effect of Microalloying on Microstructure and Mechanical Property Formation for Rolled Product of Strength Class K52 Produced Under CRU Conditions | 10.1007/s11015-020-01052-2 |
2020-11-01 | Abstract The specific features are presented of the two-stage synthesis of structured microsystems based on zinc-oxide nanorods by ultrasonic spray pyrolysis and the low-temperature hydrothermal method, with nucleation suppressed in the bulk of the solution. It is shown that the use of two-stage synthesis provides control over the size and aspect ratio of separate nanorods and over the structure of the microsystem of nanorods as a whole. It is proposed to monitor the concentration of intrinsic surface defects by measuring the photocurrent under irradiation through narrow-band interference light filters. | Two-Stage Synthesis of Structured Microsystems Based on Zinc-Oxide Nanorods by Ultrasonic Spray Pyrolysis and the Low-Temperature Hydrothermal Method | 10.1134/S1063782620110238 |
2020-11-01 | The impacts of a low temperature plasma treatment on wheat seed germination and field growth were investigated using a plasma system about the first generation (T 0 ), the second generation (T 1 ) and the third generation (T 2 ). Untreated wheat seeds were set as the control (CK). Plasma treatments of 80 W and 100 W were employed during the experiments. Germination characteristics, seedling growth parameters, biological characters and yield components were measured following the plasma treatments. The wheat seed germination index, plant height, tiller, growth and grain number obviously changed significantly after the low-temperature plasma treatment. Furthermore, the moderate-intensity plasma had an active impact on wheat seed germination and growth. The results showed that the theoretical yield of T 0 significantly increased by 8.92% and 8.14%, while the actual yield increased by 8.12% and 6.10% compared with untreated. The theoretical yield of T 1 increased by 5.69% and 6.62%, while it increased by 3.70% and 0.45% for T 2 . The actual yield of T 1 increased by 5.75% and 4.94%, while it increased by 3.81% and 0.82% for T 2 . Plasma treatment exhibited the following trend of increasing: T 0 > T 1 > T 2 > CK. We conclude that the effects of low-temperature plasma on the biological characteristics and yield components of wheat seeds exhibited a consistent trend from T 0 to T 1 to T 2 . | Effect of Low Temperature Plasma Treatment on Biological Characteristics and Yield Components of Wheat Seeds (Triticum aestivum L.) | 10.1007/s11090-020-10104-z |
2020-11-01 | Abstract The action of ozone in the low-temperature ozonization of coal tar from the semicoking of Shubarkol coal (Kazakhstan) is analyzed. Two mechanisms are possible: the electrophilic addition of ozone by π bonds to the molecules of unsaturated compounds; or radical-chain reactions with the formation of a broad spectrum of oxygen-bearing products (carboxylic acids, alcohols, aldehydes, etc.). The presence of each mechanism in tar ozonization is approximately the same. Ozone plays a positive role, by doubling the content of β fraction in the tar; and decreasing the content of the unreactive α 1 fraction. The β fraction determines the binding and clinkering properties of pitch, while the α 1 fraction prevents the appearance of anisometric needle-coke structures in pitch coking. | Action of Ozone in the Low-Temperature Ozonization of Coal Tar | 10.3103/S1068364X20110034 |
2020-11-01 | Abstract Arabidopsis thaliana Heynh . (L.) plants of the Columbia ecotype (Col-0) and its ethylene-insensitive etr1-1 (ethylene resistant 1) and ein2-1 (ethylene insensitive 2) mutants were studied. The plants were compared in respect to their cold tolerance conferred by cold acclimation. The tolerance to negative temperature increased in all the three genotypes after 5-day cooling of the plants at 2°C. Meanwhile, a quantitative difference was observed between them: the Col-0 plants survived better than the mutants, and the electrolyte leakage from the tissues reached 50% at higher (by 1°C and more) temperature in the hardened mutants than in the Col-0. Only the mutants manifested the increased lipid peroxidation over the hardening period; this indicates ROS production and general oxidative stress. From this point, we speculated that the tested Arabidopsis genotypes are different in the efficiency of their antioxidant systems. For testing, the total activities of the chief antioxidant enzymes superoxide dismutase (SOD) and catalase, including their isoenzymes, were monitored in the course of hardening. The total SOD activity was found to be lower in the mutants than in the Col-0 both at the normal growing temperature and over the whole time of the cold hardening. The isozyme analysis revealed the link of the reduced total SOD activity of the mutants with the reduced activity of their Cu/Zn-SOD isoforms at 22°C and at the beginning of the hardening. This relationship was supported by the lower relative content of the CSD1 and CSD2 gene transcripts of Cu/Zn-SOD in the mutants in comparison with the Col-0. The decrease in the total catalase activity was also observed and would be ascribed to the lowered activity of the CAT2 isoform. The reported results evidence to the principal feasibility of the ethylene signaling control of the Cu/Zn-SOD and catalase activities associated with the cold acclimation of Arabidopsis . | The Difference in Low-Temperature Tolerance of Arabidopsis thaliana Plants and Its Ethylene-Insensitive Mutants Is Related to Activities of Antioxidant Enzymes | 10.1134/S1021443720050155 |
2020-11-01 | In this article, a Schmitt trigger based 12-Transistors(ST12T) static random-access memory (SRAM) bit-cell has been proposed. The Read Power of proposed cell is reduced by 29.17%/ 24.14% /7.66% /5.87% /7.67% /16.62% when compared to 6T/ 7T/ TA8T/ 9T/ PPN10T/ D2p11T SRAM cells. Proposed ST12T cell also shows 1.52 $$\times$$ × and 1.86 $$\times$$ × lesser variability in read current and read power respectively as compared to conventional 6T SRAM cell. Further, the write access time/read access time of the proposed topology are improved by $$1.71 \times /1.82 \times$$ 1.71 × / 1.82 × as compared to 6T SRAM cell. The read power delay product of proposed ST12T cell is minimum with variation in supply voltage from 0.5 to 1 V when compared with all considered SRAM cells. ST12T SRAM cell also exhibits 26.82% and 8.87% higher read static noise margin and write static noise margin respectively as compared to conventional 6T SRAM cell. This may be attributed to Schmitt trigger design of inverters in core latch of proposed SRAM cell. The proposed bit-cell is free from half select issue and supports bit interleaving format. Authors have used cadence virtuoso tool with Generic Process Design Kit 45 nm technology file to carry out simulation. | A Schmitt-trigger based low read power 12T SRAM cell | 10.1007/s10470-020-01718-6 |
2020-11-01 | Photocatalytic CO 2 reduction is thought to be a promising strategy in mitigating the energy crisis and several other environmental problems. Hence, modifying or developing suitable semiconductors with high efficiency of photocatalytic CO 2 reduction property has become a topic of interest to scientists. In this study, a series of Mo-modified Cs 0.33 WO 3 tungsten bronze were prepared using a “water-controllable releasing” solvothermal method to produce effective photocatalytic CO 2 reduction performance. Interestingly, Mo atoms replaced W partially within the hexagonal crystal structure, leading to a significant increase in photocatalytic CO 2 reduction activity of Cs 0.33 WO 3 . The 5% Modoped compound displayed the best performance, with the production yield rates of 7.5 µmol g −1 h −1 for CO and 3.0 µmol g −1 h −1 for CH 3 OH under low concentration of CO 2 under anaerobic conditions, which is greatly higher than those of pure Cs 0.33 WO 3 (3.2 µmol g −1 h −1 for CO and 1.2 µmol g −1 h −1 for CH 3 OH) and Mo-doped W 18 O 49 (1.5 µmol g −1 h −1 for CO and 0 µmol g −1 h −1 for CH 3 OH). More importantly, the as-prepared Mo-doped Cs 0.33 WO 3 series could also induce the photocatalytic reduction of CO 2 directly from the air in the presence of oxygen, which is beneficial for practical applications. The superior photocatalytic performance of Mo-doped Cs 0.33 WO 3 series over the popular reduced WO 3 may be due to the increase in light absorption induced by the localized surface plasmon resonance (LSPR) effect of Mo 5+ , large improved charge separation ability, and the co-effect of Mo and Cs in crystal. This study provides a simple strategy for designing highly efficient photocatalysts in low concentration of CO 2 reduction. 光催化还原CO 2 被公认为一种很有潜力缓解能源危机和环 境污染的方法. 理所当然地, 改性或者开发合适的光催化材料使其 拥有高的光催化CO 2 还原活性成为了一个研究热点. 在本工作中, 我们用一种“控制水释放”的水热法制备了一系列钼改性的钨青铜 Cs 0.33 WO 3 , 以期该物质能拥有良好的光催化CO 2 还原性能. 有趣的 是, 通过部分Mo取代晶体中的W, Cs 0.33 WO 3 的光催化CO 2 还原性能 得到显著提高, 明显优于纯的Cs 0.33 WO 3 和Mo掺杂的W 18 O 49 . 5%Mo 掺杂的Cs 0.33 WO 3 在厌氧气氛中展现出了最优的光催化还原低浓度 CO2性能, 其中CO产率为7.5 μmol g −1 h −1 , 而甲醇产率为 3.0 μmol g −1 h −1 . 更重要的是, Mo掺杂的Cs 0.33 WO 3 系列在氧气存 在的条件下, 能够直接光催化还原空气气氛中的CO 2 , 这有利于其 实际应用. Mo掺杂的Cs 0.33 WO 3 光催化活性优于其他对应材料, 主 要原因是Mo 5+ 的等离子共振引起的光吸收增强、大大提高的电荷 分离能力以及Mo和Cs在晶体中的共同作用等. 本工作可能为设计 用于高效低浓度CO 2 还原的光催化材料提供一种简易的方法. | Tungsten bronze Cs0.33WO3 nanorods modified by molybdenum for improved photocatalytic CO2 reduction directly from air | 10.1007/s40843-019-1263-1 |
2020-11-01 | Effects of low concentrations of pesticides, with no or moderate mortality of targeted species, are poorly studied even though these low concentrations are common under natural conditions. Studying their effects is critical because they can induce positive hormetic responses, possibly leading to greater pest multiplication and promoting the evolution of pest resistance. Here, we investigated the responses of the pest moth Spodoptera littoralis to low concentrations of deltamethrin, and tested for variation in effects of the pesticide between developmental stages and sexes. Indeed, we show that a given concentration of deltamethrin has different effects between stages, and even between sexes. Two experimental concentrations led to very high mortality early in S. littoralis development (4th larval instar), but only to low mortality rates in adults. Moreover, our highest experimental concentration had only detrimental effects in adult females, but improved the reproductive success of adult males. Model projections showed that the lethality from treatments at the 4th larval instar was the predominant effect. Because of the high multiplication rate of S. littoralis , it was also found that treatments with very similar effects on larval mortality can lead to either population extinction or rapid pest resurgence. | Effects of low concentrations of deltamethrin are dependent on developmental stages and sexes in the pest moth Spodoptera littoralis | 10.1007/s11356-020-10181-9 |
2020-11-01 | Various methods have been suggested to realize freestanding or suspended graphene, which is expected to exhibit the intrinsic properties of graphene. However, in previously reported methods, multiple-step processes have been applied to produce freestanding graphene on a substrate. Here, we demonstrate that quasifreestanding graphene on a substrate can be realized through a simple single-step process. In this experiment, self-etching of nano-scale SiC steps of 8° off-axis vicinal SiC contributed to the formation of quasifreestanding graphene on an Si-faced SiC wafer, which was confirmed using low-energy electron diffraction, Raman spectroscopy, scanning electron microscopy and two-probe resistance measurements. Such a single-step technique for the growth of quasifreestanding graphene could pave the way towards graphene-based silicon-carbide micro-electronics. | Large-scale Growth of Quasifreestanding Graphene by using a Single-step Process | 10.3938/jkps.77.768 |
2020-11-01 | Acute lymphoblastic leukaemia (ALL) affects lymphoblastic cells and is the most common neoplasm during childhood. Among the pharmaceuticals used in the treatment protocols for ALL, Asparaginase (ASNase) from Escherichia coli (EcAII) is an essential biodrug. Meanwhile, the use of EcAII in neoplastic treatments causes several side effects, such as immunological reactions, hepatotoxicity, neurotoxicity, depression, and coagulation abnormalities. Commercial EcAII is expressed as a recombinant protein, similar to novel enzymes from different organisms; in fact, EcAII is a tetrameric enzyme with high molecular weight (140 kDa), and its overexpression in recombinant systems often results in bacterial cell death or the production of aggregated or inactive EcAII protein, which is related to the formation of inclusion bodies. On the other hand, several commercial expression strains have been developed to overcome these expression issues, but no studies on a systematic evaluation of the E. coli strains aiming to express recombinant asparaginases have been performed to date. In this study, we evaluated eleven expression strains at a low temperature (16 °C) with different characteristics to determine which is the most appropriate for asparaginase expression; recombinant wild-type EcAII (rEcAII) was used as a prototype enzyme and the secondary structure content, oligomeric state, aggregation and specific activity of the enzymes were assessed. Structural analysis suggested that a correctly folded tetrameric rEcAII was obtained using ArcticExpress (DE3), a strain that co-express chaperonins, while all other strains produced poorly folded proteins. Additionally, the enzymatic assays showed high specific activity of proteins expressed by ArcticExpress (DE3) when compared to the other strains used in this work. | Functional and structural evaluation of the antileukaemic enzyme l-asparaginase II expressed at low temperature by different Escherichia coli strains | 10.1007/s10529-020-02955-5 |
2020-11-01 | Abstract Due to sustainability issues, biodiesel must be produced from low-grade fats and the conventional homogeneously-catalyzed processes must be replaced by more efficient and more profitable production processes such as heterogeneous ones. Biodiesel (fatty acids methyl esters, FAME) was produced from a mixture (50 wt%) of soybean oil and non-edible beef tallow over heterogeneous calcium-based catalysts obtained by calcination of scallop shells. In order to improve the catalytic performances, solvent assisted methanolysis was conducted using alcohols (ethanol, 1-propanol, isopropanol and isobutanol), acetone, methylcyclohexane, and tetrahydrofuran (THF) with V methanol /V solvent = 2.8. Catalytic data revealed that alcohol solvents adsorb competitively with methanol on the catalyst active sites reducing the FAME yield due to their slower alcoholysis rates. Hexane and methylcyclohexane are inadequate for methanolysis reactions since they are immiscible with methanol. THF and acetone are immiscible with the co-produced glycerin, which favors methyl esters formation by displacing the chemical equilibrium towards reaction products. Acetone performs better than THF (FAME yield gain of 14% against 3%) because of its higher miscibility with methanol. THF was the most effective solvent to avoid fat adsorption on the catalyst surface, a key factor for catalyst stability, and to improve the glycerin purity. Graphic Abstract | Solvent Assisted Biodiesel Production by Co-processing Beef Tallow and Soybean Oil Over Calcium Catalysts | 10.1007/s12649-019-00903-7 |
2020-11-01 | Abstract—Low-alloy shipbuilding and pipeline steels are currently supplied after thermomechanical treatment, in which a ferrite–pearlite or ferrite–bainite structure depending on alloying is formed. During the thermomechanical treatment and then during cooling, a large number of defects are developed and recorded, which makes the crystalline structure nonequilibrium and leads to a nonuniform distribution of carbon and nitrogen atoms. The properties of steel with a nonequilibrium structure may degrade during processing treatments (cold straightening, bending, welding) and during exploitation or long-term storage. The effects of the modes of strain aging on the mechanism of steel fracture are studied and efficient ways to prevent embrittlement caused by aging are sought. | Effect of Aging Regimes on the Fracture Mechanism of Low-Alloy Steels with Different Structures | 10.1134/S2075113320060180 |
2020-11-01 | The first part of this study presented low-cycle fatigue and cyclic fracture toughness test methods for 10GN2MFA steel at 20 and 270°C, experimental results to construct kinetic fatigue fracture diagrams and to determine low-cycle plastic strain and fracture characteristics. Here, those results are estimated as to the application of cyclic plasticity to describe the fatigue crack growth rate. The cyclic strain-hardening coefficient and the Paris–Erdogan equation exponent for ferrite-pearlite steels are shown, to be closely related as well as the intersection point of the diagram in the range of high crack growth rates was defined. The parameters of the above relation and coordinates of the intersection point were determined for the steels of this class. In the latter case, the optimization methods were used to find the minimum sum of squares of residual functions. Based on the correlation between the cyclic strain-hardening coefficient and Paris–Erdogan equation exponent, the conclusion was drawn of the lower boundary value of this characteristic predicted for an ideal elastoplastic material (zero cyclic strain-hardening coefficient), to be equal to 1.0. As also follows, other classes of the materials (and other cycle asymmetries) can exhibit similar relations in the form of rays coming from the point (0; 1.0) at a corresponding experimental slope to the coordinate axes. From the common intersection point of the diagram (Gurney point) and their slopes to the axes for ferrite-pearlite steels, the procedure was advanced to construct the linear section of the diagram based on the results of low-cycle fatigue tests with plotting the stress amplitude vs. plastic strain amplitude curve. The procedure was approved on 10GN2MFA steel at 20 and 270°C and SAE-1020 and API5L X60 steels taken from the literature. In view of data scattering for cyclic fracture toughness test results, the estimation of the linear diagram sections is quite adequate, and the procedure of their construction is appropriate and can be extended to other classes of the materials and stress ratios. | A Study of Fatigue Crack Growth Rate in Steels in Relation to Crack-Tip Plastic Deformation and Fracture. Part 2. Parametric Relation between Fatigue Crack Growth and Plastic Strains | 10.1007/s11223-021-00244-8 |
2020-11-01 | We study a nonclassical thermal state by repeatedly operating the number operator on normal thermal state. Then, we investigate the nonclassical features of this state according to the P -function, photon-number distribution, Mandel’s Q -parameter, second-order correlation function and negative Wigner distribution as well as squeezing properties. Our results show that this state presents nonclassical properties, such as sub-Poissonian statistics, anti-bunching effects and negative Wigner distribution, at low temperature with small parameter m , which is the number of times for the number operator operates on normal thermal state. However, the squeezing effect of this state is not found. | Generating a Nonclassical Thermal State Via Number Operators | 10.1007/s10909-020-02509-z |
2020-11-01 | Abstract The effect of metal corrosion on the third-order microscopic properties, i.e., the root-mean-square deviation and internal residual stresses of the first-order, was studied. The corrosion process was studied on steel specimens under conditions of superheated steam (250°C) during 500 h. The X-ray diffraction method was taken as the basic research method. The process of corrosion failure was concluded to have two reproducible periods: the period of active metal dissolution and latent passivation period, followed by the corrosion initiation phase. The metal passivity occurs due to the compressive stresses. | Microstructural Aspects of Corrosion | 10.1134/S1027451020060361 |
2020-11-01 | Ethylenediaminetetraacetic acid (EDTA) can serve as a washing agent in the remediation of low-permeability layers contaminated by heavy metals (HMs). Therefore, batch adsorption experiments, where pure quartz (SM1) and mineral mixtures (SM2) were used as typical soil minerals (SMs) in low-permeability layers, were implemented to explore the effects of different EDTA concentrations, pH, and exogenous chemicals on the HM-SM-EDTA adsorption system. As the EDTA concentration increased, it gradually cut down the maximum Cd adsorption capacities of SM1 and SM2 from approximately 135 to 55 mg/kg and 2660 to 1453 mg/kg; and the maximum Pb adsorption capacities of SM1 and SM2 were reduced from 660 to 306 mg/kg and 19,677 to 19,262 mg/kg, respectively. When the initial mole ratio (MR = moles of HM ions/sum of moles of HM ions and EDTA) was closer to 0.5, the effect of EDTA was more effective. Additionally, EDTA worked well at pH below 7.0 and 4.0 for Cd and Pb, respectively. Low-molecular-weight organic acids (LMWOAs) affected the system mainly by bridging, complexation, adsorption site competition, and reductive dissolution. Cu 2+ , Fe 2+ ions could significantly increase the Cd and Pb adsorption onto SM2. Notably, there were characteristic changes in mineral particles, including attachment of EDTA and microparticles, agglomeration, connection, and smoother surfaces, making the specific surface area (SSA) decrease from 16.73 to 12.59 m 2 /g. All findings indicated that EDTA could effectively and economically reduce the HM adsorption capacity of SMs at the reasonable MR value, contact time, and pH; EDTA reduced the HM adsorption capacity of SMs not only by complexation with HM ions but also by decreasing SSA and blocking active sites. Hence, the acquired insight from the presented study can help to promote the remediation of contaminated low-permeability layers in groundwater. | Effects of EDTA on adsorption of Cd(II) and Pb(II) by soil minerals in low-permeability layers: batch experiments and microscopic characterization | 10.1007/s11356-020-10149-9 |
2020-11-01 | Abstract The corrosion inhibition property of the Uncaria gambir extract (UGE) for the low-carbon steel was investigated in a prepared cooling-water solution using gravimetric analysis and potentiodynamic polarization measurements. Anticorrosive effectiveness was tested at the UGE concentrations of 0–1500 ppm and temperatures of 40–60°C. The CaCO 3 scale inhibition performance was evaluated following NACE standard TM 0374-2007 and ASTM D511-03. The surface morphology was analyzed by scanning electron microscopy. It was found that increasing the UGE concentration increased its anticorrosive effectiveness. A 70% corrosion inhibition efficiency and a 31% CaCO 3 scale inhibition efficiency were observed during the use of 1500 ppm UGE. A change in the morphology of CaCO 3 precipitate was observed due to the adsorption of the UGE, which suppressed the regular growth process. Increasing temperature decreased the effectiveness of the UGE. A higher corrosion potential and a reduction of anodic reactivity were also observed. The UGE acted as anodic inhibitor and conformed the Langmuir adsorption isotherm. | Effects of Concentration and Temperature on Corrosion and Scale Inhibitive Behavior of Uncaria gambir Extract for Low-Carbon Steel in Cooling-Water Solution | 10.3103/S1068375520060137 |
2020-11-01 | Background/objective This work applied a newly developed low-cost sensing (LCS) device (AS-LUNG-P) and a certified medical LCS device (Rooti RX) to assessing PM 2.5 impacts on heart rate variability (HRV) and determining important exposure sources, with less inconvenience to subjects. Methods Observations using AS-LUNG-P were corrected by side-by-side comparison with GRIMM instruments. Thirty-six nonsmoking healthy subjects aged 20–65 years were wearing AS-LUNG-P and Rooti RX for 2–4 days in both Summer and Winter in Taiwan. Results PM 2.5 exposures were 12.6 ± 8.9 µg/m 3 . After adjusting for confounding factors using the general additive mixed model, the standard deviations of all normal to normal intervals reduced by 3.68% (95% confidence level (CI) = 3.06–4.29%) and the ratios of low-frequency power to high-frequency power increased by 3.86% (CI = 2.74–4.99%) for an IQR of 10.7 µg/m 3 PM 2.5 , with impacts lasting for 4.5–5 h. The top three exposure sources were environmental tobacco smoke, incense burning, and cooking, contributing PM 2.5 increase of 8.53, 5.85, and 3.52 µg/m 3 , respectively, during 30-min intervals. Significance This is a pioneer in demonstrating application of novel LCS devices to assessing close-to-reality PM 2.5 exposure and exposure–health relationships. Significant HRV changes were observed in healthy adults even at low PM 2.5 levels. | Panel study using novel sensing devices to assess associations of PM2.5 with heart rate variability and exposure sources | 10.1038/s41370-020-0254-y |
2020-11-01 | WSN can be a tech in-full development with top-notch, outstanding foreseeable future. The utilization of wireless sensor network (WSN) to get a good quality observation is consists using some range of detector nodes having a network capacity which might be set up for productive effects or to get constant monitoring function. Water is critical within our own lives because of our wellbeing insurance and in different cases such as farming, marketplace, and for the animal’s presence. Diseases linked to inadequate sanitation and water states have over 200 million cases reported causing 5–10 million deaths throughout the world. Water tracking procedures are indispensable to restrain exactly the challenge is gently linked to inadequate household allocation, wasteful usage and too little decent. Wireless sensor networks also have gained fame over the study area only because they supply a promising infrastructure for both multiple monitoring and control software. For fixing the dilemma, various drinking water caliber processes were grown previously in the last ten years. The parameters included with the drinking water quality tracking would be the PH degree, turbidity, dissolved oxygen and temperature has been quantified at the true period from the detectors that ship the info into the bottom channel or control/monitoring space. This document suggests the way the tracking platform might be set up highlighting the elements of low-cost, simple setup, and effortless maintenance and handling. Using this radio platform for tracking purpose is not only going to lower the total observation procedure expenditure in the duration of centers installation and labor price tag but can even offer versatility in the duration of location or distance. In this paper, the essential layout and execution of WSN comprising Lora (wide area network) established technological innovation is suggested. The developed system is cheap and makes it possible for customization. A few preliminary links between dimension to rate the efficiency and efficiency of the machine can also be shown. | Smart City Based Autonomous Water Quality Monitoring System Using WSN | 10.1007/s11277-020-07655-x |
2020-11-01 | Abstract In this study, a novel laboratory-scale synchronous enhanced biological phosphorus removal and semi-nitritation (termed as EBPR-SN) combined with anammox process was put forward for achieving nutrient elimination from municipal wastewater at 27 ℃. This process consisted of two 10 L sequencing batch reactors (SBRs), i.e. EBPR-SN SBR followed by Anammox SBR. The EBPR-SN SBR was operated for 400 days with five periods and the Anammox SBR was operated starting on period IV. Eventually, for treating municipal wastewater containing low chemical oxygen demand/nitrogen (COD/N) of 3.2 (mg/mg), the EBPR-SN plus Anammox system performed advanced total inorganic nitrogen (TIN) and P removal, with TIN and P removal efficiencies of 81.4% and 94.3%, respectively. Further analysis suggested that the contributions of simultaneous partial nitrification denitrification, denitrification, and anammox to TIN removal were 15.0%, 45.0%, and 40.0%, respectively. The enriched phosphorus-accumulating organisms (PAOs) in the EBPR-SN SBR facilitated P removal. Besides, the EBPR-SN SBR achieved P removal and provided stable anammox substrates, suggesting a short sludge retention time (SRT 12 d) could achieve synergy between ammonia-oxidizing bacteria and PAOs. These results provided an alternative process for treating municipal wastewater with limited organics. Graphic abstract | Advanced nitrogen and phosphorus removal from municipal wastewater via simultaneous enhanced biological phosphorus removal and semi-nitritation (EBPR-SN) combined with anammox | 10.1007/s00449-020-02392-8 |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.