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2022-04-15 | A low-background neutron detector array was developed to measure the cross section of the $$^{13}$$ 13 C( $$\alpha$$ α ,n) $$^{16}$$ 16 O reaction, which is the neutron source for the s -process in AGB stars, in the Gamow window ( $$E_\text {c.m.}$$ E c.m. = 190 ± 40 keV) at the China Jinping Underground Laboratory (CJPL). The detector array consists of 24 $$^{3}$$ 3 He proportional counters embedded in a polyethylene cube. Owing to the deep underground location and a borated polyethylene shield around the detector array, a low background of 4.5(2)/h was achieved. The $$^{51}$$ 51 V(p, n) $$^{51}$$ 51 Cr reaction was used to determine the neutron detection efficiency of the array for neutrons with energies $$E_\text {n}<$$ E n < 1 MeV. Geant4 simulations are shown to effectively reproduce the experimental results. They were used to extrapolate the detection efficiency to higher energies for neutrons emitted in the $$^{13}$$ 13 C( $$\alpha$$ α ,n) $$^{16}$$ 16 O reaction. The theoretical angular distributions of the $$^{13}$$ 13 C( $$\alpha$$ α ,n) $$^{16}$$ 16 O reaction were shown to be important in the estimation of the uncertainties of the detection efficiency. | Development of a low-background neutron detector array | 10.1007/s41365-022-01030-0 |
2022-04-15 | In this paper we study ergodic optimization and multifractal behavior of Lyapunov exponents for matrix cocycles. We show that the restricted variational principle holds for generic cocycles [in the sense of (Bonatti and Viana in Ergod Theory Dyn Syst 24(5):1295–1330, 2004)] over mixing subshifts of finite type. We also show that the Lyapunov spectrum is equal to the closure of the set where the entropy spectrum is positive for such cocycles. Moreover, we show the continuity of the entropy spectrum at boundary of Lyapunov spectrum in the sense that $$h_{top}(E(\alpha _{t}))\ \rightarrow h_{top}(E(\beta ({\mathcal {A}}))$$ h top ( E ( α t ) ) → h top ( E ( β ( A ) ) , where $$E(\alpha )=\{x\in X: \lim _{n\rightarrow \infty }\frac{1}{n}\log \Vert {\mathcal {A}}^{n}(x)\Vert =\alpha \}$$ E ( α ) = { x ∈ X : lim n → ∞ 1 n log ‖ A n ( x ) ‖ = α } , for such cocycles. We prove the continuity of the lower joint spectral radius for linear cocycles under the assumption that linear cocycles satisfy a cone condition. | Lyapunov Spectrum Properties and Continuity of the Lower Joint Spectral Radius | 10.1007/s10955-022-02910-w |
2022-04-15 | Background Studies have demonstrated that elderly people with low back pain (LBP) may have poor postural control compared to healthy older adults. Poor postural control is associated with poor balance performance and a high risk of serious falls. A variety of training strategies are proposed for LBP therapy, particularly core stabilization training. But this treatment for older people with LBP remains unclear. Methods 31 participants were randomly placed in a core stability training group (TG, n = 15) and a control group (CG, n = 16). The participants in the training group were required to complete 4 sets of core stability training and conventional physiotherapy 4 times per week for 4 weeks, whereas the participants in the control group only completed physiotherapy 4 times per week for 4 weeks. Ultrasound imaging was used to measure transverse abdominal muscle (TrA) thickness before and after the intervention. A 10-cm visual analog scale (VAS), the Oswestry Disability Index (ODI), and mobility functions were applied before and after the intervention. Data are reported as the median and range and were compared using two-way repeated-measures ANOVA,t-tests and chi-squared tests. P < 0.05 was considered significant in all statistical tests. Results After intervention, there was a statistically significant difference in scores in the intervention group, especially for VAS, ODI, timed up-and-go,10-m walking and the four-square step test. TrA thickness was increased after core stability training, which was not observed in the control group. Conclusion Core stability training is an effective intervention for older women with LBP. | Effects of core stability training on older women with low back pain: a randomized controlled trial | 10.1186/s11556-022-00289-x |
2022-04-13 | Background Viral pneumonias are a major cause of childhood mortality. Proper management needs early and accurate diagnosis. This study objective is to investigate the viral etiologies of pneumonia in children. Results This prospective study enrolled 158 and 101 patients in the first and second year, respectively, and their mean age was 4.72 ± 2.89. Nasopharyngeal swabs were collected and subjected to virus diagnosis by reverse transcription polymerase chain reaction (RT-PCR). Viral etiologies of pneumonia were evidenced in 59.5% of the samples in the first year, all of them were affirmative for influenza A, 2 samples were affirmative for Human coronavirus NL63, and one for Human coronavirus HKU1. In the second year, 87% of patients had a viral illness. The most prevalent agents are human metapneumovirus which was detected in 44 patients (43.6%) followed by human rhinovirus in 35 patients (34.7%) and then parainfluenza–3 viruses in 33 patients (32.7%), while 14 patients had a confirmed diagnosis for both Pan coronavirus and Flu-B virus. Conclusions Viral infection is prevalent in the childhood period; however, the real magnitude of viral pneumonia in children is underestimated. The reverse transcriptase polymerase chain reaction has to be a vital tool for epidemiological research and is able to clear the gaps in-between clinical pictures and final diagnoses. | Prevalence of viral pathogens in a sample of hospitalized Egyptian children with acute lower respiratory tract infections: a two-year prospective study | 10.1186/s42269-022-00790-4 |
2022-04-11 | Abstract Air quality was measured before, during, and after a 4th of July fireworks display in downtown Minneapolis, Minnesota using a mix of low-cost sensors (CO, CO 2 , and NO) for gases and portable moderate cost instruments for particle measurements (PM 2.5 , lung deposited surface area, and number weighted particle size distributions). Meteorological conditions—temperature, humidity, and vertical temperature profile were also monitored. Concentrations of particles and most gaseous species peak between 10 pm and midnight on July 4th, decrease in the middle of the night but increase again and by between 6 and 7 am reach concentrations as high or higher than during fireworks. This overnight increase is likely due to a temperature inversion trapping emissions. Between 10 pm and midnight on July 4th the measures of particle concentration increase by 180–600% compared to the same period on July 3rd. Particle size distributions are strongly influenced by fireworks, shifting from traffic-like bimodal distributions before to a nearly unimodal distribution dominated by a large accumulation mode during and after. The shape of the size distribution measured during the early morning peak is nearly identical to that observed during fireworks, suggesting that the early morning peak is mainly due to trapped fireworks emissions not early morning traffic. Gaseous species are less strongly influenced by fireworks than particles. Comparing measurements made between 10 pm and midnight on July 4th and the same period on July 3rd, the concentration of CO increases 32% while the CO 2 increases only 2% but increases by another 15% overnight. The NO concentration behaves oddly, decreasing during fireworks, but then recovering the next morning, more than doubling overnight. Our measurements of CO, NO, and PM 2.5 are compared with those made at the nearest (~ 2 km away) Minnesota Pollution Control Agency Air Monitoring Station. Their NO results are quite different from ours with much lower concentrations before fireworks, a distinct peak during, followed by a strong overnight increase and an early morning peak somewhat similar in shape and concentration to ours. These differences are likely due mainly to malfunction of our low-cost NO sensor. Concentrations of CO and PM 2.5 track ours within 25% but peak shapes are somewhat different, which is not unexpected given the spatial separation of the measurements. Article highlights Low-cost and moderate-cost sensors are used to monitor the impact of a 4th of July fireworks display on local air quality. Particle concentrations and size are more strongly influenced by fireworks than are concentrations gaseous pollutants. Particle size distributions produced by fireworks are distinctly different from those associated with urban traffic sources. | Measuring the effect of fireworks on air quality in Minneapolis, Minnesota | 10.1007/s42452-022-05023-x |
2022-04-09 | The formation of calcium oxychloride in cold conditions due to a reaction between calcium chloride deicing salt and calcium hydroxide in the concrete causes substantial damage to pavement concretes. In this study, the role of supplementary cementitious materials (SCMs) in mitigating damage in cement pastes and mortars exposed to highly concentrated CaCl 2 solutions and low temperatures is elucidated. Cementitious paste and mortar mixtures designed with different SCM replacement levels were prepared and immersed in 25% CaCl 2 solutions and subject to low-temperature cycles (− 8–25 °C) for 360 days (180 cycles). Damage was reduced as the SCM replacement level and curing time were increased, as confirmed by bulk resistivity, visual observation, and light microscopy measurements. Substantial differences between paste and mortar behavior were observed with the mortars outperforming pastes. | Damage in cement pastes and mortars exposed to CaCl2 and low-temperature cycles | 10.1617/s11527-022-01949-1 |
2022-04-08 | In this paper, a mesa-type 256 × 8 long-wavelength infrared detector is prepared by using InAs/GaSb type-II superlattice (T2SL) material with double barrier structure. The area of each pixel is 25 × 25 μm 2 . The cut-off wavelength and dark current density of the detector at −0.05 V bias with liquid nitrogen temperature are 11.5 μm and 4.1 × 10 –4 A/cm 2 , respectively. The power spectral densities of low-frequency noise under different temperatures have also been fitted through the Hooge model, and the correlations with dark current are extracted subsequently. The results shown that the 1/f noise of the detector is mainly caused by the generation-recombination current at a low reverse bias, however, when the reverse bias is high, the 1/f noise should be expressed by the sum of I gr noise and I btb noise which was ignored in the previous research. The 1/f noise-current correlation assessed in this work can provide insight into the low frequency noise characteristics of InAs/GaSb T2SL long-wavelength detectors, and allow us to understand the main source of low-frequency noise better. | Investigation of low frequency noise-current correlation for the InAs/GaSb type-II superlattice long-wavelength infrared detector | 10.1007/s11082-021-03450-5 |
2022-04-08 | Background In Japan, six workers handling cross-linked water-soluble acrylic acid polymer (CWAAP) at a chemical plant suffered from lung diseases, including fibrosis, interstitial pneumonia, emphysema, and pneumothorax. We recently demonstrated that inhalation of CWAAP-A, one type of CWAAP, causes pulmonary disorders in rats. It is important to investigate dose–response relationships and recoverability from exposure to CWAAPs for establishing occupational health guidelines, such as setting threshold limit value for CWAAPs in the workplace. Methods Male and female F344 rats were exposed to 0.3, 1, 3, or 10 mg/m 3 CWAAP-A for 6 h/day, 5 days/week for 13 weeks using a whole-body inhalation exposure system. At 1 h, 4 weeks, and 13 weeks after the last exposure the rats were euthanized and blood, bronchoalveolar lavage fluid, and all tissues including lungs and mediastinal lymph nodes were collected and subjected to biological and histopathological analyses. In a second experiment, male rats were pre-treated with clodronate liposome or polymorphonuclear leukocyte-neutralizing antibody to deplete macrophages or neutrophils, respectively, and exposed to CWAAP-A for 6 h/day for 2 days. Results CWAAP-A exposure damaged only the alveoli. The lowest observed adverse effect concentration (LOAEC) was 1 mg/m 3 and the no observed adverse effect concentration (NOAEC) was 0.3 mg/m 3 . Rats of both sexes were able to recover from the tissue damage caused by 13 weeks exposure to 1 mg/m 3 CWAAP-A. In contrast, tissue damage caused by exposure to 3 and 10 mg/m 3 was irreversible due to the development of interstitial lung lesions. There was a gender difference in the recovery from CWAAP-A induced pulmonary disorders, with females recovering less than males. Finally, acute lung effects caused by CWAAP-A were significantly reduced by depletion of alveolar macrophages. Conclusions Pulmonary damage caused by inhalation exposure to CWAAP-A was dose-dependent, specific to the lung and lymph nodes, and acute lung damage was ameliorated by depleting macrophages in the lungs. CWAAP-A had both a LOAEC and a NOAEC, and tissue damage caused by exposure to 1 mg/m 3 CWAAP-A was reversible: recovery in female rats was less than for males. These findings indicate that concentration limits for CWAAPs in the workplace can be determined. Graphical Abstract | Dose–response relationship of pulmonary disorders by inhalation exposure to cross-linked water-soluble acrylic acid polymers in F344 rats | 10.1186/s12989-022-00468-9 |
2022-04-08 | Background Acute lower respiratory infection (ALRI) remains the leading cause of death in children worldwide, and viruses have been the major cause of ALRI. In Myanmar, ALRI is associated with high morbidity and mortality in children, and detailed information on ALRI is currently lacking. Methods This prospective study investigated the viral aetiologies, clinical manifestations, and outcomes of ALRI in hospitalised children aged 1 month to 12 years at the Yankin Children Hospital, Yangon, Myanmar from May 2017 to April 2019. The sample size was set to 300 patients for each year. Two nasopharyngeal swabs were obtained for the patients with suspected viral ALRI; one for rapid tests for influenza and respiratory syncytial virus (RSV), and the other for real-time PCR for the 16 ALRI-causing viruses. Pneumococcal colonization rates were also investigated using real-time PCR. Clinical information was extracted from the medical records, and enrolled patients were categorised by age and severity for comparison. Results Among the 5463 patients admitted with a diagnosis of ALRI, 570 (10.4%) were enrolled in this study. The median age of the patients was 8 months (interquartile range, 4–15 months). The most common symptoms were cough (93%) and difficulty in breathing (73%), while the most common signs of ALRI were tachypnoea (78%) and chest indrawing (67%). A total of 16 viruses were detected in 502 of 570 patients’ samples (88%), with RSV B (36%) and rhinovirus (28%) being the most commonly detected. Multiple viruses were detected in 221 of 570 samples (37%) collected from 570 patients. Severe ALRI was diagnosed in 107 of 570 patients (19%), and RSV B and human rhinovirus were commonly detected. The mortality rate was 5%; influenza virus A (29%) and RSV B (21%) were commonly detected, and stunting and lack of immunization were frequently observed in such cases. Additionally, 45% (259/570) of the patients had pneumococcal colonization. Conclusions Viral ALRI in hospitalised children with a median of 8 months has significant morbidity and mortality rates in Myanmar. RSV and rhinovirus were the most commonly detected from nasopharyngeal swabs, while influenza virus and RSV were the most frequently associated with fatal cases. | Clinical manifestations and outcome of viral acute lower respiratory infection in hospitalised children in Myanmar | 10.1186/s12879-022-07342-1 |
2022-04-07 | Background Helictotrichon virescens is a perennial grass that is primarily distributed in high altitude areas of 2000 ~ 4500 m. It is widely cultivated in the Qinghai-Tibet Plateau of China, strongly resistant to cold, and an essential part of the wild herbs in this region. However, the molecular mechanism of the response of H. virescens to low temperature stress and the key regulatory genes for specific biological processes are poorly understood. Results Physiological and transcriptome analyses were used to study the cold stress response mechanism in H virescens. During the low temperature stress period, the content of chlorophyll a and b decreased more and more with the delay of the treatment time. Among them, the difference between the controls was not significant, and the difference between the control and the treatment was significant. At the same time, the expression of related differential genes was up-regulated during low temperature treatment. In addition, the plant circadian pathway is crucial for their response to cold stress. The expression of differentially expressed genes that encode LHY and HY5 were strongly up-regulated during cold stress. Conclusions This study should help to fully understand how H. virescens responds to low temperatures. It answers pertinent questions in the response of perennial herbs to cold stress, i.e., how light and low temperature signals integrate to regulate plant circadian rhythms and Decrease of content of chlorophylls (which can be also accompanied with decrease of total quantity of reaction centers) leads to an increase in photosynthetic damage. | Physiological attributes and transcriptomics analyses reveal the mechanism response of Helictotrichon virescens to low temperature stress | 10.1186/s12864-022-08526-4 |
2022-04-07 | Background To evaluate the effects of 0.02% and 0.01% atropine eye drops on ocular and corneal astigmatism over 2 years. Methods A prospective clinic-controlled trail. The cohort study assessed 400 myopic children and divided them into three groups: 138 and 142 children were randomized to use either 0.02% or 0.01% atropine eye drops, respectively. They wore single-vision (SV) spectacles, with one drop of atropine applied to both eyes once nightly. Control children ( n = 120) only wore SV spectacles. Spherical equivalent refractive errors (SER) and corneal curvature were measured every 4 months. The SER and corneal curvature were assessed by cycloplegic autorefraction and IOLMaster. Ocular and corneal astigmatism were calculated by Thibos vector analysis and then split into its power vector components, J0 (with-the-rule astigmatism) and J45 (oblique). Results After 2 years, the ocular astigmatism increased by -0.38 ± 0.29 D, -0.47 ± 0.38 D, -0.41 ± 0.35 D in the 0.02%, 0.01% atropine groups and control group, respectively ( p = 0.15). The corresponding corneal astigmatism increased by -0.20 ± 0.34 D, -0.28 ± 0.35 D and -0.26 ± 0.26 D ( p = 0.18). The ocular astigmatism J0 increased by 0.19 ± 0.28 D, 0.22 ± 0.36 D, 0.18 ± 0.31 D in the 0.02% atropine, 0.01% atropine and control groups, respectively ( p = 0.65). The corresponding corneal astigmatism J0 increased by -0.05 ± 0.34 D, -0.11 ± 0.37 D and -0.13 ± 0.30 D ( p = 0.23). There was a small but significant increase in ocular astigmatism (including J0) (all P < 0.05), but there were no changes in the ocular astigmatism J45 and corneal astigmatism (including J0 and J45) in the three groups over time (all p > 0.05). However, there were no significant differences in the changes in ocular astigmatism (including J0) among the three groups. Conclusions Treatment with 0.02% and 0.01% atropine had no clinically significant effect on ocular and corneal astigmatism over 2 years. Trial registration The First Affiliated Hospital of Zhengzhou University, ChiCTR-IPD-16008844 . Registered 14/07/2016. | Effect of 0.02% and 0.01% atropine on astigmatism: a two-year clinical trial | 10.1186/s12886-022-02385-z |
2022-04-04 | Background Dry powder (DP) synthetic lung surfactant may be an effective means of noninvasive delivery of surfactant therapy to premature infants supported with nasal continuous positive airway pressure (nCPAP) in low-resource settings. Methods Four experimental DP surfactant formulations consisting of 70% of phospholipids (DPPC:POPG 7:3), 3% Super Mini-B (SMB) or its sulfur-free derivate B-YL as SP-B peptide mimic, 25% of lactose or trehalose as excipient, and 2% of NaCl were formulated using spray drying. In vitro surface activity was confirmed with captive bubble surfactometry. Surfactant particle size was determined with a cascade impactor and inhaled dose was quantified using a spontaneously breathing premature lamb lung model supported with CPAP. In vivo surfactant efficacy was demonstrated in three studies. First, oxygenation and lung compliance were monitored after intratracheal instillation of resuspended DP surfactant in intubated, ventilated, lavaged, surfactant-deficient juvenile rabbits. In dose–response studies, ventilated, lavaged, surfactant-deficient rabbits received 30, 60, 120 or 240 mg/kg of DP B-YL:Lactose or B-YL:Trehalose surfactant by aerosol delivery with a low flow aerosol chamber via their endotracheal tube. Noninvasive aerosolization of DP B-YL:Trehalose surfactant via nasal prongs was tested in spontaneous breathing premature lambs supported with nCPAP. Intratracheal administration of 200 mg/kg of Curosurf ® , a liquid porcine surfactant, was used as a positive control. Results Mass median aerosol diameter was 3.6 μm with a geometric standard deviation of 1.8. All four experimental surfactants demonstrated high surface efficacy of intratracheal instillation of a bolus of ~ 100 mg/kg of surfactant with improvement of oxygenation and lung compliance. In the dose–response studies, rabbits received incremental doses of DP B-YL:Lactose or B-YL:Trehalose surfactant intratracheally and showed an optimal response in oxygenation and lung function at a dose of 120–240 mg/kg. Aerosol delivery via nasal prongs of 1 or 2 doses of ~ 100 mg/kg of B-YL:Trehalose surfactant to premature lambs supported with nCPAP resulted in stabilization of spontaneous breathing and oxygenation and lung volumes comparable to the positive control. Conclusion These studies confirm the clinical potential of DP synthetic lung surfactant with B-YL peptide as a SP-B mimic to alleviate surfactant deficiency when delivered as a liquid bolus or as an aerosol. | Efficacy, dose–response, and aerosol delivery of dry powder synthetic lung surfactant treatment in surfactant-deficient rabbits and premature lambs | 10.1186/s12931-022-02007-8 |
2022-04-04 | Background Benign prostatic hyperplasia (BPH) is inescapable with aging and can cause lower urinary tract symptoms, worsening the quality of life. New pathophysiologic mechanisms of BPH development are currently under study to modulate its management. The valvular destruction of the spermatic veins (varicoceles development) incurs a testicular-prostatic hydrostatic pressure gradient, which conveys free undiluted testosterone to the prostate via a testicular-prostatic backdoor passage. Subsequently, prostatic congestion and androgen-dependent prostatic hyperplasia occur resulting in lower urinary symptoms development. The purpose of our study is to detect the effect of testicular venous sclerotherapy on the prostatic enlargement and the related urinary symptoms. Results Our single-arm interventional study included 36 patients with an age range of 40–80 years. The patients complained of urinary symptoms and had prostatomegaly with varicoceles by sonography. A median international prostatic symptom score (IPSS) of 19 and a quality of life (QoL) score ranging (3–6) reflected the severity of the urinary symptoms. Venography showed reflux in all cannulated spermatic veins with subsequent sclerotherapy on the left side and bilaterally in 80.6% and 11.1% of the patients, respectively. The technical and clinical success rates reached 91.7% and 83.3%, respectively, with a statistically significant reduction in the IPSS and QoL scores. We observed a statistically insignificant improvement in the sexual satisfaction, prostatic volumes, post-void residual volumes, and PSA levels. Minimal self-limiting complications occurred with an overall rate of 38.9%. Only 16.66% of cases needed further surgery, while the rest had sufficient symptomatic relief post sclerotherapy. Conclusion Varicoceles sclerotherapy can be employed to resolve the testicular venous insufficiency and mitigate the severity of the prostatic-related urological symptoms in middle-aged and elderly men, so varicoceles can be considered a confounding variable in the development of the prostatic-related lower urinary tract symptoms. | Role of varicocele sclerotherapy in the management of benign prostatic hyperplasia and its associated lower urinary tract symptoms (pilot study) | 10.1186/s43055-022-00758-4 |
2022-04-02 | Background The identification of indeterminate pulmonary nodules (IPNs) following a low-dose computed tomography (LDCT) is a major challenge for early diagnosis of lung cancer. The inadequate assessment of IPNs’ malignancy risk results in a large number of unnecessary surgeries or an increased risk of cancer metastases. However, limited studies on non-invasive diagnosis of IPNs have been reported. Methods In this study, we identified and evaluated the diagnostic value of circulating small extracellular vesicle (sEV) microRNAs (miRNAs) in patients with IPNs that had been newly detected using LDCT scanning and were scheduled for surgery. Out of 459 recruited patients, 109 eligible patients with IPNs were enrolled in the training cohort (n = 47) and the test cohort (n = 62). An external cohort (n = 99) was used for validation. MiRNAs were extracted from plasma sEVs, and assessed using Small RNA sequencing. 490 lung adenocarcinoma samples and follow-up data were used to investigate the role of miRNAs in overall survival. Results A circulating sEV miRNA (CirsEV-miR) model was constructed from five differentially expressed miRNAs (DEMs), showing 0.920 AUC in the training cohort (n = 47), and further identified in the test cohort (n = 62) and in an external validation cohort (n = 99). Among five DEMs of the CirsEV-miR model, miR-101-3p and miR-150-5p were significantly associated with better overall survival (p = 0.0001 and p = 0.0069). The CirsEV-miR scores were calculated, which significantly correlated with IPNs diameters (p < 0.05), and were able to discriminate between benign and malignant PNs (diameter ≤ 1 cm). The expression patterns of sEV miRNAs in the benign, adenocarcinoma in situ/minimally invasive adenocarcinoma, and invasive adenocarcinoma subgroups were found to gradually change with the increase in aggressiveness for the first time. Among all DEMs of the three subgroups, five miRNAs (miR-30c-5p, miR-30e-5p, miR-500a-3p, miR-125a-5p, and miR-99a-5p) were also significantly associated with overall survival of lung adenocarcinoma patients. Conclusions Our results indicate that the CirsEV-miR model could help distinguish between benign and malignant PNs, providing insights into the feasibility of circulating sEV miRNAs in diagnostic biomarker development. Trial registration : Chinese Clinical Trials: ChiCTR1800019877. Registered 05 December 2018, https://www.chictr.org.cn/showproj.aspx?proj=31346 . Graphical Abstract | Identification and evaluation of circulating small extracellular vesicle microRNAs as diagnostic biomarkers for patients with indeterminate pulmonary nodules | 10.1186/s12951-022-01366-0 |
2022-04-01 | This work reviews technologies that can be used to develop low-temperature solid oxide cells (LT-SOCs) and can be applied in fuel cells and electrolyzers operating at temperatures below 500°C, thus providing a more cost-effective alternative than conventional high-temperature SOCs. Two routes showing potential to reduce the operating temperature of SOCs to below 500°C are discussed. The first route is the principal way to enhance cell performance, namely, structure optimization. This technique includes the reduction of electrolyte thickness to the nanometer scale and the exploration of electrode structure with low polarization resistance. The other route is the development of novel proton-conducting electrolyte materials, which is in the frontier of SOCs study. The fundamentals of proton conduction and the design principles of commonly used electrolyte materials are briefly explained. The most widely studied electrolyte materials for LT-SOCs, namely, perovskite-type BaCeO 3 - and BaZrO 3 -based oxides, and the effect of doping on the physical—chemical properties of these oxide materials are summarized. | Recent progress in the structure optimization and development of proton-conducting electrolyte materials for low-temperature solid oxide cells | 10.1007/s12613-022-2447-y |
2022-04-01 | Large scale applications of metal-iodine batteries working at sub-zero degree have been challenged by the limited capacity and performance degradation. Herein, we firstly propose a Zn-I 2 battery working at low temperature with a carbon composite material/iodine (CCM-I 2 ) cathode, a Zn anode and an environmentally tolerable Zn(ClO 4 ) 2 -ACN electrolyte. The CCM framework with hierarchical porous structure endows a powerful iodine-anchoring to overcome undesirable dissolution of iodine in organic electrolyte, and the Zn(ClO 4 ) 2 -ACN electrolyte with low freezing point and high ionic conductivity enhances the low temperature performance. The synergies enable an efficiently reversible conversion of Zn-I 2 battery even at −40 ° C. Therefore, the resultant Zn-I 2 battery delivers a high specific capacity of 200 mAh·g −1 , which is fairly approximate to the theoretical capacity of l 2 (211 mAh·g −1 ) and a superior cycling stability with minimal capacity fading of 0.00043% per cycle over 7,000 times under 2C at −20 ° C. Furthermore, even at −40 ° C, this Zn-I 2 battery still exhibits a good capacity retention of 68.7% compared to the capacity at 25 °C and a rapid capacity-recover ability with elevating temperature change. Our results distinctly indicate this Zn-I 2 battery can be competent for the practical application under low temperature operation. | High performance Zn-I2 battery with acetonitrile electrolyte working at low temperature | 10.1007/s12274-021-3884-z |
2022-04-01 | The effect of different modes of heating, viz. current-controlled and temperature-controlled modes, on the upper and lower cycle temperatures during partial thermal cycling of a binary near-equiatomic Ni-Ti shape memory alloy under constant stress was experimentally investigated . The sheet specimens were subjected to partial thermal cycling ( T min < M f to T max < A f ), keeping the stress constant at 100 MPa, for 1000 cycles. The heating of the sample to a predetermined temperature was done by passing an electric current by two different methods: 1. current-controlled mode (supplying a current of constant magnitude for a fixed length of time) and 2. temperature-controlled mode (fixing the upper cycle temperature using a temperature feedback mechanism). An analysis of the cycling temperature reveals that there is an increase in the lower cycle temperature during the temperature-controlled mode of heating. In contrast, both upper and lower cycle temperatures vary significantly during the current-controlled mode of heating. | Effect of Mode of Heating on Cyclic Temperature Range during Partial Thermal Cycling under Constant Stress of a Near-Equiatomic Ni-Ti Shape Memory Alloy | 10.1007/s11665-021-06410-y |
2022-04-01 | In this paper, we report the fabrication of cobalt-doped de-NO x catalyst by pyrolyzing an analogous metal-organic framework-74 (MOF-74) containing Fe & Mn. The resulted catalyst exhibits distinctive microstructures of manganese, cobalt, and iron immobilized on N-doped carbon nanotubes (CNTs). It is found through experiments that the trimetallic catalyst Fe 2 Mn 1 Co 0.5 /CNTs-50 has the best NH 3 -selective catalytic reduction (SCR) performance. The Fe 2 Mn 1 Co 0.5 /CNTs-50 exhibited excellent water and sulfur resistance and good stability under the harsh gas environment of 250 °C and/or 170 °C, NO = NH 3 = 1,000 ppm, 8 vol.% O 2 , 20 vol.% H 2 O, 1,000 ppm SO 2 , and gas hourly space velocity (GHSV) = 75,000 h −1 . The de-NO x conversion was maintained about 55% and 25% after 192 h. The water and sulfur resistance performance were much higher than commercial vanadium series catalyst. The highly water and sulfur resistance performance may be attributed to the unique core-shell microstructure and the synergistic effect of manganese, cobalt, and iron which helps reduce the formation for byproducts (NH 4 HSO 4 ). This study may promote to explore the development of a high stability catalyst for low-temperature selective catalytic reduction of NO x with NH 3 . | Cobalt doped Fe-Mn@CNTs catalysts with highly stability for low-temperature selective catalytic reduction of NOx | 10.1007/s12274-021-3932-8 |
2022-04-01 | The present study examined the effect of aging on asphalt concrete low-temperature cracking using mechanical test and the surface free energy (SFE) method that is based on the main properties of the material. Twelve combinations of asphalt mixture were prepared using two types of aggregate (limestone and granite), two types of performance-graded asphalt cement (PG 64-16 and PG 58-22), and ultra-high-molecular-weight polyethylene additive (UHMWPE) at 2% of the asphalt cement mass. The low-temperature cracking of asphalt concrete was evaluated by the mechanical semicircular bending (SCB) test at three temperatures, and the thermodynamic tests were performed by determining the SFE components of the asphalt cement and aggregates using the Wilhelmy plate test and the universal sorption device (USD), respectively. The results of the SCB mechanical test indicated that the values of fracture energy and fracture toughness parameters, which are known as an index for determining the sensitivity of asphalt concrete to low-temperature cracking, were lower for aged asphalt concrete than control mixtures. The decrease in asphalt concrete resistance due to aging was more evident in the PG 58-22 asphalt cement than the PG 64-16 asphalt cement. The results of the SFE tests demonstrated that aging increased the non-polar component (between 19.2% and 42.4%) and decreased the acid (between 26.5% and 108.3%) and base (between 6.8% and 10.6%) components of the SFE in asphalt cements. These caused a rise in the free energy of cohesion (between 1.5% and 4.5%) and a reduction in the free energy of adhesion (between 0.3% and 3%), suggesting that the asphalt mixture resistance to failure increased in the mastic, and the resistance to failure decreased at the asphalt cement-aggregate contact surface due to aging. Furthermore, UHMWPE incorporation promoted the cohesion (between 41.0% and 52.1%) and adhesion (between 9.6% and 11.8%) energies of the modified asphalt concrete, thereby reducing the thermal cracking potential of the modified asphalt concrete. Besides, aging had little effect on the SFE components, fracture energy, and fracture toughness parameters of the modified asphalt concrete. | The Effect of Long-Term Aging on Low-Temperature Cracking of Asphalt Concrete Using Mechanical and Thermodynamic Methods | 10.1007/s40999-021-00669-x |
2022-04-01 | This is the first study to conduct the flash sintering of 3 mol% yttria-stabilized zirconia (3YSZ) ceramics at room temperature (25 °C) under a strong electric field, larger than 1 kV/cm. At the standard atmospheric pressure (101 kPa), the probability of successful sintering is approximately half of that at low atmospheric pressure, lower than 80 kPa. The success of the proposed flash sintering process was determined based on the high electric arc performance at different atmospheric pressures ranging from 20 to 100 kPa. The 3YSZ samples achieved a maximum relative density of 99.5% with a grain size of ∼200 nm. The results showed that as the atmospheric pressure decreases, the onset electric field of flash sintering decreases, corresponding to the empirical formula of the flashover voltage. Moreover, flash sintering was found to be triggered by the surface flashover of ceramic samples, and the electric arc on the sample surfaces floated upward before complete flash sintering at overly high pressures, resulting in the failure of flash sintering. This study reveals a new method for the facile preparation of flash-sintered ceramics at room temperature, which will promote the application of flash sintering in the ceramic industry. | Gas-discharge induced flash sintering of YSZ ceramics at room temperature | 10.1007/s40145-021-0561-3 |
2022-04-01 | The fatigue tests of Chinese RPV steel (A508-3) were carried out under the simulated primary coolant environment of AP1000 which is a kind of 3rd generation nuclear power plant. The effects of temperature, strain rate and dissolved oxygen (DO) on fatigue life were analyzed. During the fatigue test, the material exhibited a cyclic hardening followed by cyclic softening behavior, with no obvious cyclic stability region. In logarithmic coordinates, the S–N curve showed a bilinear relationship. As the strain amplitude increased from 0.2 to 0.6%, the fatigue life approximately decreased from 10 5 to 3 × 10 2 . The environmental correction factor (Fen), which is defined as the ratio of life in air at room temperature to that in the primary coolant environment, decreases as the temperature decreases from 321 to 150 °C. The Fen also decreases as the DO decreases from 0.6 to 0.03 ppm while it increases as the strain rate decreases from 1 to 0.0004%/s. Compared with the NUREG6909 model, the presented model is more applicable for fatigue life prediction of Chinese A508-3 steel. | Effect of environmental media on the fatigue property of Chinese A508-3 steel of AP1000 | 10.1007/s10704-021-00589-w |
2022-04-01 | In this study, the smoke from a 3R4F research cigarette and the aerosol generated by the Heated Tobacco Product IQOS, also referred to as the Tobacco Heating System (THS) 2.2 in the literature, were compared. The objective was to characterize the gas and suspended particulate matter compositions in the mainstream smoke from a combusted 3R4F cigarette and in the aerosol generated by IQOS during use. The results indicated that the determined aerosol emissions from IQOS were notably lower than in the cigarette smoke under a Health Canada Intense puffing regimen. As an interesting detail in this study, the maximum nicotine concentrations within a puff were practically the same in both the 3R4F smoke and the IQOS aerosol, but the average concentration was lower for the IQOS aerosol. For both products, water constituted a significant proportion of the particulate matter, although it was substantially higher in the IQOS aerosol. Furthermore, combustion-related solid particles observed in the 3R4F smoke contained elements such as carbon, oxygen, potassium, calcium, and silicon. In contrast, IQOS aerosol particulate matter was composed of semi-volatile organic constituents with some minor traces of oxygen and silicon. The particulate matter found in the IQOS aerosol was volatile, which was especially noticeable when exposed to the electron beam of the scanning electron microscope (SEM) and Transmission Electron Microscope (TEM). | Comparison of 3R4F cigarette smoke and IQOS heated tobacco product aerosol emissions | 10.1007/s11356-021-18032-x |
2022-04-01 | Photothermal therapy (PTT) has shown promising applications in tumor therapies. However, due to laser-induced nonspecific heating and heat diffusion, high levels of hyperthermia (>50°C) in tumor tissues often increase the risk of cancer recurrence and metastasis, which causes the patient pain and destroys the surrounding normal cells and tissues. It is therefore important to develop photothermal strategies that have excellent therapeutic efficiencies under low-temperature conditions (≤45°C). In addition, the heterogeneity and complexity of tumors require the development of combinatorial antitumor treatments as the therapeutic efficiency of monomodal PTT is not currently sufficient. Herein, we have adopted a stepwise synthetic approach to develop a highly efficient multimodal therapeutic agent GA@PCOF@PDA by successive bonding defect functionalization (BDF), guest encapsulation, and surface modification steps. The covalently grafted porphyrinic photosensitizers (Por), encapsulated gambogic acid (GA), and surface-modified PDA film are independently responsible for photodynamic therapy (PDT), heat-shock protein 90 (HSP90) down-regulation and chemotherapy (CT), and low-temperature PTT. This proof-of-concept study illustrates an efficient, generalized approach to design high-performance covalent organic framework (COF)-based nanoagents that can be easily tailored to combine different therapeutic modalities for improved cancer theranostics at low temperatures. 光热疗法(PTT)在肿瘤治疗中有着广阔的应用前景. 然而, 由于激光诱导的非特异性加热与热扩散现象的存在, 高温热(>50°C)在破坏肿瘤的同时可能导致肿瘤附近正常器官被灼伤, 给患者带来癌症复发和转移的风险. 因此, 在低温加热下(≤45°C)有效破坏肿瘤对光学癌症治疗方法的未来临床转化具有重要价值. 此外, 由于肿瘤的异质性和复杂性, 使得单模态PTT的治疗效果不佳, 需要发展联合抗肿瘤治疗策略.基于此, 我们采用逐步合成的方法, 依次通过键合缺陷功能化、客体包封和表面修饰步骤, 开发了一种高效的多模式纳米治疗剂GA@PCOF@PDA. 该纳米制剂可在低温条件下实现光热/化疗/光动力联合治疗, 进而有效地抑制肿瘤的生长和转移. 该研究表明, 我们可以通过共价有机框架(COF)纳米平台的多功能集成化, 实现在单一纳米平台上的多模式肿瘤治疗, 进而提高治疗效果. | Nanoscale covalent organic framework for the low-temperature treatment of tumor growth and lung metastasis | 10.1007/s40843-021-1805-x |
2022-04-01 | The effect of high-temperature thermomechanical treatment (HTMT) with deformation in the austenitic region on the regularities of low-temperature embrittlement of low-activation 12% chromium ferritic-martensitic steel EK-181 is investigated in comparison with traditional heat treatment (THT) during dynamic tests on impact toughness and static tests on uniaxial tension in the range from −196 to 20°C. It is found out that HTMT increases both the tensile strength properties of steel and its impact toughness. At the same time, the temperature of its ductile-brittle transition does not practically change relative to the THT. It is observed that the features of steel microstructure after HTMT, the formation of delaminations (during fracture of Charpy-type specimens) in the planes parallel to the plane of hot rolling, have a positive effect on its impact toughness. | Effect of High Temperature Thermomechanical Treatment on the Tendency of Low-Activation 12% Cr Ferritic-Martensitic Steel EK-181 to Low-Temperature Embrittlement | 10.1007/s11182-022-02581-w |
2022-04-01 | In recent decades, highly alloyed low-density steels are being developed to reduce the weight of different automotive parts. Dilatometry can be a very useful experimental technique to understand phase transformations during heating or cooling of new low-density steel alloys. When performing dilatometry measurements some assumptions are made such as the homogeneity of the sample material tested during the experiment. In this study, dilatometry tests were performed for two different low-density steels, and the variations of the composition between the surface and the inner part of the sample were analyzed. The migration of manganese by diffusion from the interior of the samples and finally its evaporation on the surface under vacuum were observed. This compositional gradient generated in the samples may influence the veracity and interpretation of the results obtained in dilatometry when working with high manganese steel alloys. The detachment of surface grains created by this compositional change near the surface of the samples is also investigated. | Different Phenomena Encountered during Dilatometry of Low-density Steels | 10.1007/s11665-021-06418-4 |
2022-04-01 | South China can be divided into four metallogenic belts: The Middle-Lower Yangtze Metallogenic Belt (MLYB), Qinzhou-Hangzhou Metallogenic Belt (QHMB), Nanling Metallogenic Belt (NLMB), and Wuyi Metallogenic Belt (WYMB). The major mineralization in the four metallogenic belts is granite-related Cu–Au–Mo and porphyrite Fe-apatite, porphyry Cu (Au), and epithermal Pb–Zn–Ag, hydrothermal Cu–Au–Pb–Zn–Ag, and granite-related skarn-type and quartz-veins W–Sn, respectively. Low-temperature thermochronology, including fission-track and U-Th/He dating, has been widely used to constrain tectonic thermal evolution and ore deposits preservation. Understanding fission-track annealing and He diffusion kinetics in accessory minerals, such as zircon and apatite, is essential for dating and applications. In this study, previous zircon fission-track (ZFT) and apatite fission-track (AFT) ages in South China were collected. The result shows that the ZFT ages are mainly concentrated at 140–90 Ma, and the AFT ages are mainly distributed at 70–40 Ma. The age distribution and inversion temperature–time paths reveal heterogeneous exhumation histories in South China. The MLYB experienced Late Cretaceous-Cenozoic extremely slow exhumation after rapid cooling in the Early Cretaceous. The northern QHMB (i.e. from southern Anhui province to the Hangzhou Bay) had a relatively faster rate of uplifting and denudation than the southern QHMB in the Cretaceous. Subsequently, the northern QHMB rapidly exhumed, while the continuously slow exhumation operated the southern QHMB in the Cenozoic. The southern NLMB had a more rapid cooling rate than the northern NLMB during the Cretaceous time, and the whole NLMB experienced rapid cooling in the Cenozoic, except that the southern Hunan province had the most rapid cooling rate. The WYMB possibly had experienced slow exhumation since the Late Cretaceous. The exhumation thickness of the four metallogenic belts since 90 Ma is approximately calculated as follows: the MLYB ≤ 3.5 km, the northern QHMB concentrated at 3.5–5.5 km, and the southern QHMB usually less than 3.5 km, the NLMB 4.5–6.5 km and the WYMB < 3.5 km. The exhumation thickness of the NLMB is corresponding to the occurrence of the world-class W deposits, which were emplaced into a deeper depth of 1.5–8 km. As such, we infer that the uplifting and denudation processes of the four metallogenic belts have also played an important role in dominated ore deposits. | Application of low-temperature thermochronology on ore deposits preservation framework in South China: a review | 10.1007/s11631-021-00506-x |
2022-04-01 | The present article aims at elucidating the effect of thermo-mechanical controlled processing (TMCP), especially the finish cooling temperature, on microstructure and mechanical properties of high strength low alloy steels for developing superior low temperature toughness construction steel. The microstructural features were characterized by scanning electron microscope equipped with electron backscatter diffraction, and the mechanical behaviors in terms of tensile properties and impact toughness were analyzed in correlation with microstructural evolution. The results showed that the lower finish cooling temperature could lead to a considerable increase in impact toughness for this steel. A mixed microstructure was obtained by TMCP at lower finish cooling temperature, which contained much fine lath-like bainite with dot-shaped M/A constituent and less granular bainite and bainite ferrite. In this case, this steel possesses yield and ultimate tensile strengths of ~ 885 MPa and 1089 MPa, respectively, and a total elongation of ~ 15.3%, while it has a lower yield ratio of ~ 0.81. The superior impact toughness of ~ 89 J at −20 °C was obtained, and this was resulted from the multi-phase microstructure including grain refinement, preferred grain boundaries misorientation, fine lath-like bainite with dot-shaped M/A constituent. | Correlation of Microstructure Feature with Impact Fracture Behavior in a TMCP Processed High Strength Low Alloy Construction Steel | 10.1007/s40195-021-01250-0 |
2022-04-01 | Machine-learning and big data are among the latest approaches in corrosion research. The biggest challenge in corrosion research is to accurately predict how materials will degrade in a given environment. Corrosion big data is the application of mathematical methods to huge amounts of data to find correlations and infer probabilities. It is possible to use corrosion big data method to distinguish the influence of the minimal changes of alloying elements and small differences in microstructure on corrosion resistance of low alloy steels. In this research, corrosion big data evaluation methods and machine learning were used to study the effect of Sb and Sn, as well as environmental factors on the corrosion behavior of low alloy steels. Results depict corrosion big data method can accurately identify the influence of various factors on corrosion resistance of low alloy and is an effective and promising way in corrosion research. | Data-mining and atmospheric corrosion resistance evaluation of Sn- and Sb-additional low alloy steel based on big data technology | 10.1007/s12613-022-2457-9 |
2022-04-01 | An advanced cogeneration system based on biomass direct combustion was developed and its feasibility was demonstrated. In place of the traditional single heat source (extraction steam), the extraction steam from the turbine, the cooling water from the plant condenser, and the low-pressure feedwater from the feedwater preheating system were collectively used for producing district heat in the new scheme. Hence, a remarkable energy-saving effect could be achieved, improving the overall efficiency of the cogeneration system. The thermodynamic and economic performance of the novel system was examined when taking a 35 MW biomass-fired cogeneration unit for case study. Once the biomass feed rate and net thermal production remain constant, an increment of 1.36 MW can be expected in the net electric production, because of the recommended upgrading. Consequently, the total system efficiency and effective electrical efficiency augmented by 1.23 and 1.50 percentage points. The inherent mechanism of performance enhancement was investigated from the energy and exergy aspects. The economic study indicates that the dynamic payback period of the retrofitting project is merely 1.20 years, with a net present value of 5796.0 k$. In conclusion, the proposed concept is validated to be advantageous and profitable. | Performance evaluation of an improved biomass-fired cogeneration system simultaneously using extraction steam, cooling water, and feedwater for heating | 10.1007/s11708-021-0741-4 |
2022-04-01 | Templated sol–gel synthesis of silica materials with hexagonally ordered mesoporous structure was realized in the presence of amphiphilic organic compounds (azo dyes, bile acid, cyclic oligosaccharide) as cosurfactants and alkoxysilane derivatives prepared on their basis as structure-forming silanes. The effect of auxiliary agents on mesoporous structure of resulting silicas was estimated by low-temperature nitrogen adsorption–desorption and x-ray diffraction analysis. It was found that introduction of moderate amounts of amphiphilic organic additives or their alkoxysilane derivatives in sol–gel reaction mixture causes formation of silica materials with higher surface area and more distinct long-range ordered pore system. Obtained results open up new opportunities for synthesis of MCM-41-type silica materials with improved structural characteristics. | Role of amphiphilic organic additives in design of silica materials with ordered mesoporous structure | 10.1007/s10934-021-01167-0 |
2022-04-01 | In this paper, the effect of low-temperature treatment on bacterial activity was investigated and its performance in preparing the consolidated sand was accessed. Four factors, including absorbance (OD600), pH, electric conductivity (EC) and urease activity (UA) were monitored to evaluate the bacterial activity. Moreover, the calcium carbonate yields under different bacterial solution and cementation solution volume ratios were determined Finally, the compressive strength and microstructure of consolidated sand were investigated and the mechanism was explored by characterising the products among sand particles. The results showed that for both continuous and interval cultivation of bacteria, stable bacterial solution was harvested within the cultivation period of 30 h. Low-temperature treatment showed limited inhibition at early cultivation stage, while it had strong inhibition at middle cultivation stage The interval cultivation improved the cultivation efficiency of bacteria It was observed that the low-temperature preservation for a stable bacterial solution has little influence on UA before 4 days, while UA decreased seriously after its preservation time was extended to over 8 days. The optimal volume ratio of bacterial solution and substrate solution was 1:1, resulting in the highest calcium carbonate yield. The improved compressive strength of consolidated sand after 3 injections was attributed to the irregular-shaped calcite products, which coated and bonded the sand grains together. | Effect of low-temperature treatment on bacterial cultivation in bacterial induced mineralization | 10.1007/s11431-021-1937-5 |
2022-04-01 | Underground low-background laboratories have a very large demand for radon reduction in their working environments. Therefore, in this paper, we have constructed a system for low-temperature activated carbon adsorption of radon by using air cooler and measured the dynamic adsorption coefficients of activated carbon on radon at room temperature and at a low temperature below − 50 °C. The experimental results show that the activated carbon dynamic adsorption coefficient reaches 688.79 L/g at a temperature of − 63.35 °C and a pressure of 3.5 atmospheres, which is more than 70 times higher than that at room temperature. During the experiments, problems of effective regulation were identified that need to be further addressed. | Construction of a low-temperature activated carbon radon adsorption system using air cooler | 10.1007/s10967-022-08270-9 |
2022-04-01 | Ulva prolifera is an edible and potentially economically valuable green alga. Temperature is one of the primary factors limiting the optimal quality and yields of U. prolifera . Mutants of U. prolifera show superior production and quality characteristics. For instance, the HF-6 strain with low-temperature tolerance (LTT) can survive well at temperatures as low as 12 °C. To dissect metabolic responses and identify promising metabolite markers, we compared the metabolomes of the HF-6 and wild-type (WT) strains at 12 °C. Based on orthogonal partial least squares-discriminant analysis (OPLS-DA), volcano plot, and the receiver operating characteristic (ROC) curve analysis, six potential candidate biomarkers, glucose, galactose, panose, oxalic acid, glutamic acid (Glu), and glycine were selected. Three of these markers (glucose, galactose, and panose) were sugars, indicating that high concentrations of sugars were correlated with increased low-temperature tolerance. Oxalic acid and Glu have been commonly reported to be associated with antioxidants in plants. Further studies showed that exogenous Glu could enhance the cold tolerance capacity of U. prolifera at a concentration of 0.5 mg L −1 , and it also significantly increased the relative growth rate and relative electron transfer rate (rETR) of U. prolifera relative to those of the control group. Thus, the ability of U. prolifera to tolerate low temperatures may be enhanced by regulating glycometabolism and antioxidant metabolism. To our knowledge, this is the first study of the mechanism of U. prolifera tolerance to low temperature based on comparing the metabolomics of mutant and WT strains, and it provides important insights into the mechanisms involved in the low-temperature tolerance of U. prolifera . | Potential biomarkers of low-temperature tolerance in Ulva prolifera strains | 10.1007/s10811-021-02666-y |
2022-04-01 | The Pt thin-film cathode thermo-mechanically reinforced by using atomic layer-deposited (ALD) alumina overcoat for low-temperature solid oxide fuel cells was investigated on electrochemical and electrical performances and its area specific resistance (ASR) with respect to cell dimension was evaluated. The nanoporous Pt thin-film cathode was fabricated by direct current magnetron sputtering with a deposition pressure of 50 mTorr. And alumina overcoat was deposited with thermal ALD 30 cycles onto the nanoporous Pt thin-film cathode. Compared to bare Pt thin-film cathode, ALD alumina-overcoated Pt thin-film cathode provided ~ 3-times lower activation ASR and ~ 2-times lower effective electrical conductivity after 4-h operation at 550 °C. Despite increases in the thermo-mechanical stability of Pt thin-film cathode by ALD alumina overcoating, it was evaluated that the total ASR of ALD alumina-overcoated Pt thin-film cathode was lower than that of the bare Pt thin-film cathode only if cell dimension is below 0.95 cm 2 because of its lower current collecting performance in the in-plane direction. | Is Coating Oxide on Porous Metal Thin-Film for Low-Temperature Solid Oxide Fuel Cell Cathode a Panacea for Performance Enhancement? | 10.1007/s12541-022-00628-z |
2022-04-01 | Thermally activated hydrochars prepared from mango peels have been tested for continuous removal of lead ions from contaminated drinking water for possible use in point-of-use candle-type water filters. The hydrochar was obtained using low-temperature hydrothermal carbonization, which was activated at various temperatures to produce activated hydrochars. The materials have been characterized physicochemically according to ASTM standards for activated carbons. The structure and morphology were studied by FTIR, XRD, SEM and nitrogen adsorption porosimetry. The results obtained showed that hydrochar activated at 400 °C (ACH 400) was promising for the elimination of lead with a obtained equilibrium absorption capacity of 38.31 mg/g at the optimized height parameters of bed (2.4 cm), flow rate (12 mL/min) and lead concentration (100 mg/L). The results of the experimental breakthrough curves given by adsorption process were successfully fitted by kinetic models according to Adams–Bohart, Thomas and Yoon–Nelson in their linearized forms. The Thomas and Yoon-Nelson data provided a better correlation with the prediction of the breakthrough curve data with high R 2 values, showing a good agreement between the breakthrough curves and the experimental data points. ACH 400 is a suitable sorbent in place of activated carbon for a continuous system and can be applied for large-scale treatment for the removal of lead from water samples. | Thermally activated mango peels hydrochar for fixed-bed continuous flow decontamination of Pb(II) ions from aqueous solution | 10.1007/s13762-021-03272-8 |
2022-04-01 | In this paper, a novel low power and high write margin Darlington based NCNTFET Darlington 8T SRAM cell is proposed. The power consumption of the proposed Darlington SRAM cell is compared with that of conventional 6T CNTFET and conventional 8T CNTFET SRAM cells. The power consumption of the proposed Darlington SRAM cells is very less as compared to that of conventional 6T and 8T CNTFET SRAM cells for all write, hold, and read operations. The write static noise margin (WSNM) of the proposed NCNTFET Darlington 8T cell is found to increase by 70.83% than that of both conventional 6T and 8T CNTFET SRAM cell. Effect of CNTFET parameters such as chiral vectors (m,n), gate oxide thickness (Hox), dielectric constant of gate oxide material (Kox), temperature, pitch value, number of carbon nano tubes (CNTs) and supply voltage (VDD), on the power performance, drain current (I D ) and drain to source voltage (VDS) of the novel proposed Darlington SRAM cell are investigated. The write, hold, and read power consumption of proposed NCNTFET Darlington 8T SRAM cell is compared with that of some of the existing SRAM cells. The simulation is carried out using Stanford University 32 nm CNTFET model. | Darlington Based 8T CNTFET SRAM Cells with Low Power and Enhanced Write Stability | 10.1007/s42341-021-00329-w |
2022-04-01 | Raman scattered light is generated by the interaction of irradiated light with molecular vibrations, and it provides molecular information. Although Raman shifts of peaks in the low-frequency region (< 200 cm −1 ) provide useful information related to molecular structures, there are no reliable materials available for calibrating Raman spectrometers in this region. In this study, we chose high-purity l -cystine (NMIJ CRM 6025-a) and used it to reliably evaluate Raman shifts of peaks with uncertainty by a combination of HeNe laser and Ne emission lines. To evaluate their uncertainty, we considered the uncertainty originating from wavenumbers of Ne emission lines and HeNe laser, evaluation of wavenumber for peak-tops and changes in temperature. The obtained Raman shifts of eight peaks from 9 to 160 cm −1 and their uncertainty were 0.3 cm −1 or 0.4 cm −1 and these values were validated with the results using a 532 nm laser. Graphical abstract | Reliable estimation of Raman shifts for peaks of l-cystine (NMIJ CRM 6025-a) in the low-frequency region | 10.1007/s44211-022-00080-z |
2022-04-01 | This paper reports on the possibility of performing Friction Stir Welding (FSW) without the usual immanent shoulder to enable FS processing to deep welding of narrow and labile structures and applications where backing is not possible. Requirements and prerequisites, advantages and limitations for Shoulderless Friction Stir Welding (SLFSW) are discussed and an industrial application of the joining technology is presented. For leaving the shoulder out, its central functions in FSW have to be transferred to the pin. The resulting tool design of SLFSW is comparably small and slim and so reduces contact area and effective lever and in turn forces and heat input during processing. SLFSW allows welding paths almost at the edge of components and enables a complete and gap-free joining while a deformation of overhanging structures can be avoided. Compared to standard FSW processes, force reductions of about 80–85 % and power reductions of about 75–80 % were found in this study for a 6.5 mm deep weld opening up additional potential for integration with other spindle processes like milling. The locally very limited process impact of SLFSW resulted in comparably low distortion with a part precision reached of +/− 0.05 mm. | Shoulderless Friction Stir Welding: a low-force solid state keyhole joining technique for deep welding of labile structures | 10.1007/s11740-021-01083-x |
2022-04-01 | Low salinity waterflooding has gained significant attention and importance in the last decade, as it is seen as an impactful method for recovery of additional oil from carbonate reservoirs. Existing literature does not do justice to the underlying mechanisms that aid in the recovery of additional oil from such rock types. In this paper, we present a comprehensive review of the research conducted on low salinity waterflooding in carbonates and further provide a detailed and critical analysis on the same. The intention of this paper is also to present a condensed research summary on the said topic, and to chart out a detailed roadmap for future work, thereby opening the possibilities of new avenues of research in the field. | A review on low salinity waterflooding in carbonates: challenges and future perspective | 10.1007/s13202-021-01361-5 |
2022-04-01 | The effect of Cu-riched clusters on strength and impact toughness in a tempered Cu-bearing high-strength low-alloy (HSLA) steel is investigated. With increasing the tempering temperature, it is found that the yield strength increases firstly, achieving the maximum value (~ 1053 MPa) at the tempering temperature of 450 °C, and then decreases significantly with the rise of tempering temperature. The tempering temperature-dependent yield strength is closely related to the precipitation of Cu-riched clusters. When tempering at 450 °C, the peak strength will be reached as the nanoscale Cu-riched clusters with small size and high number density will cause a strong precipitation strengthening (~ 492 MPa) due to the dislocation shearing mechanism. However, the Cu-riched clusters will coarsen with further increasing tempering temperature, resulting in obvious decrement of yield strength owing to the dislocation bypassing mechanism. Compared with the yield strength, the variation in impact energy displays an inverse tendency and the impact energy is only 7 J for the sample tempered at 450 °C. The fracture mode can be well explained by the competition between the cleavage fracture strength ( σ F ) and “yield strength” ( σ Y ). Although transgranular cleavage fracture can be found in samples tempered at 450 and 550 °C, the crack propagation along the lath boundaries is prevented in the sample tempered at 550 °C. The reason is that the number density of Cu-riched clusters at lath boundaries decreases and the segregation of Mo element at the lath boundaries is induced, which will increase the bonding energy. | Effect of Nanoscale Cu-Riched Clusters on Strength and Impact Toughness in a Tempered Cu-Bearing HSLA Steel | 10.1007/s40195-021-01277-3 |
2022-04-01 | Abstract Alkaline tungstate crystals are promising scintillation materials for rare events search, especially for WIMP investigations. Na 2 W 2 O 7 single crystals doped with 1.0 mol.% chromium and cerium ions are grown from melt by low-thermal-gradient Czochralski technique (LTG Cz) developed at Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciece (Novosibirsk, Russia) for obtaining large oxide scintillating crystals of high optical quality. Obtained doped Na 2 W 2 O 7 single crystals 25 mm in length and 30 mm in diameter. The photoluminescence excitation and emission spectra, as well as the decay curves in the temperature range of 77-300 K are measured and colorimetric parameters are estimated. Comparative studies of the photoluminescence properties of Na 2 W 2 O 7 crystals undoped and doped with Ce 3+ and Cr 3+ ions in the temperature range of 77-300 K are is carried out. It is shown that while the introduction of cerium and chromium ions in the Na 2 W 2 O 7 crystal lattice does not significantly a effect the colorimetric parameters and optical properties, it does not increase mechanical hardness of the crystals and decreases the tendency to cracking along cleavage planes. The emission color chromaticity coordinates, сorrelated color temperature and color purity for Na 2 W 2 O 7 :Ce and Na 2 W 2 O 7 :Cr crystals are calculated. The photoluminescence lifetimes are calculated and a strong temperature dependence of the lifetimes in the range 77-300 K is shown. | GROWTH AND SPECTROSCOPIC INVESTIGATIONS OF Na2W2O7 SINGLE CRYSTALS DOPED WITH CERIUM AND CHROMIUM IONS | 10.1134/S0022476622040084 |
2022-04-01 | Abstract The structure and mechanical properties of the titanium alloy VT6 joint diffusion welded in vacuum at 820°C using an ultrafine-grained interlayer made of alloy VT22 in are studied after annealing at 900°C for 2 h. The heating-induced activation of diffusion processes is found to halve the number of micropores in the weld zone and to increase the tensile strength of the welded joint from 975 to 1108 MPa. The impact toughness of this joint after heat treatment corresponds to the initial impact toughness of the VT6 alloy. | Effect of Heat Treatment on the Structure and Mechanical Properties of the Solid-Phase VT6 Alloy Welded Joint with an Ultrafine-Grained VT22 Alloy Interlayer | 10.1134/S003602952204022X |
2022-04-01 | Abstract The effect of low-frequency acoustic treatment on the viscosity, temperature, and energy parameters and the adhesion properties of a petrolatum-based fat composition, which is used at mining and processing plants of the diamond mining industry, was studied. The field treatment of the fat composition was accompanied by a decrease in the melting point, viscosity, and viscous flow activation energy. At the same time, the composition retained fluidity for 8 h without losing adhesive properties. The level of energy costs for heating the composition was several times lower than that with traditional thermal technology. | Physical Treatment for the Regulation of the Physicochemical Properties of a Petrolatum-Based Composition | 10.3103/S0361521922020057 |
2022-04-01 | Low density polyethylene (LDPE) based nanocomposite films made from different levels of nanoclay, compatibilizer and thickness were evaluated for the storage stability of sugarcane juice for 60 days under ambient condition. During the storage period, important physico-chemical properties such as pH, total sugars, total soluble solids and overall acceptability were decreased with respect to increased level of nanoclay and compatibilizer as well as decreased thickness of film. Total plate count was nil till the storage period of 15 days and then there was an increase in microbial population. Similarly, the overall color difference was also increased during the storage period. The better storage stability with respect to biochemical characteristics, overall acceptability and microbial load was recorded in the 100 µm thick LDPE nano composite films developed from 93 percent LDPE, 2 percent nanoclay and 5 percent compatibilizer. | Low-density polyethylene based nanocomposite packaging films for the preservation of sugarcane juice | 10.1007/s13197-021-05174-6 |
2022-04-01 | We add the σ -modification and the low-frequency learning to the model reference adaptive controller (MRAC) (Guduri et al. in SN Appl Sci 3:1–21, 2021) to make it robust in the presence of two simultaneous bounded disturbances and maintain consistent mean particles’ temperature and velocity collectively called mean particles’ states (MPSs) when they impact the substrate to be coated. The MPSs affect the coating quality. Even though results are applicable to several coating processes, we consider an atmospheric plasma spray process (APSP). It is shown that the proposed controller can quickly adopt to disturbances in the average injection velocity of powder particles and in the arc voltage to change the input current, and the argon and the hydrogen flow rates to maintain constant values of the MPSs. The effects of the parameter values in the MRAC, the MRAC with $$\sigma$$ σ -modification (R-MRAC), and the R-MRAC with low-frequency learning (MR-MRAC) schemes on tracking error convergence, steady-state tracking error, disturbance rejection and the presence of overshoot have been studied. The numerical experiments suggest that $$2 \le \gamma \le 20,$$ 2 ≤ γ ≤ 20 , $$10 \le \sigma \le 100,$$ 10 ≤ σ ≤ 100 , and $$20 \le \lambda \le 80$$ 20 ≤ λ ≤ 80 for the MR-MRAC provide fast adaptation, no overshoot, and low tracking error in the controlled response. The parameter $$\lambda > 0$$ λ > 0 suppresses high-frequency oscillations in the closed-loop control system, and $$\gamma$$ γ serves to tune the controller gains. The control scheme has been tested using the software, LAVA-P, that simulates well an APSP. | Robust model reference adaptive controller for atmospheric plasma spray process | 10.1007/s42452-022-05012-0 |
2022-04-01 | Purpose A graphene thermophone requires a substrate to support its extremely thin structure. It is essential to determine the characteristic parameters and selection principles of substrates and gases in both low- and high-frequency ranges for improving the sound pressure of graphene thermophones. Methods First, the theoretical models for thermoacoustic emission from a graphene on a substrate are established. Analytical expressions of the sound pressure are derived based on analysis of the thermal piston sound source. Then, experimental results of graphene on various transparent substrates are presented to verify the theoretical models. Finally, performance parameters of substrates and gases are summarized and analyzed including the thermal effusivity of substrates, the heat capacity per unit area of substrates, the thermal effusivity of gases and the heat capacity of gases. Results The theoretical predictions agree well with the experimental results. At high frequencies, a lower thermal effusivity of substrates leads to a higher sound pressure. While at low frequencies, the heat capacity per unit area can be selected as the evaluation parameter for substrates. Substrates with a lower heat capacity show better acoustic performances. The performance evaluation parameters of ambient gases can be concluded as the thermal effusivity and the heat capacity for thermoacoustic emission at both high and low frequencies. For gases, the higher thermal effusivity combined with the lower heat capacity is better to achieve a higher sound pressure. Conclusions The theoretical models are applicable to on-substrate thermophones and the results are useful to the optimization of the gas/graphene/substrate multilayer structures. | Characteristic Parameters and Selection Principles of Substrates and Gases for Graphene Thermophones | 10.1007/s42417-022-00432-z |
2022-04-01 | With the increasing requirement for the analysis of nonlinear and transient behaviors in plasma systems, the demand for particle-in-cell (PIC) simulations is increasing. However, most plasma simulations have utilized fluid models because of the high computational cost of the PIC simulation. This article introduces the most recent advances in the electrostatic particle-in-cell simulations of low-temperature plasmas for materials processing. The parallelization in multi-dimensional geometry using heterogeneous computing and the method to treat curved boundaries are explained to improve the PIC simulation. Test examples of two-dimensional hollow cathode discharges and three-dimensional magnetron sputtering systems are presented to investigate the kinetic effects of the system. | Multi-dimensional electrostatic plasma simulations using the particle-in-cell method for the low-temperature plasmas for materials processing | 10.1007/s40042-021-00375-w |
2022-04-01 | Aims Plant investment in sexual reproduction is affected by nitrogen (N): phosphorus (P) stoichiometry. It has been suggested that an important adaptation to strong P limitation is reduced investment in sexual reproduction. We aim to investigate the specific influence of N:P on sexual reproduction performance within and between grassland species. Methods Eleven grassland species were selected in ten plots covering N limitation, co-limitation and P limitation. Nutrients in soil and above-ground biomass were determined, plus soil pH and soil moisture. A range of sexual reproduction traits were measured as a proxy for investment in sexual reproduction. Results At the intraspecific level: compared with N-limited plots, in P-limited/co-limited plots, flowering time was later, flowering period in individuals was shorter, and number of flowers (inflorescences) per individual was smaller. At the interspecific level, in P-limited/co-limited plots, species had a significantly earlier flowering time and a longer seed stalk and seed panicle, than those in N-limited plots. However, flowering period was shorter and number of flowers (inflorescences) per individual was smaller under P limitation/co-limitation. Moreover, significant correlations between soil pH and soil moisture, and sexual reproduction performance of the selected grassland species were also found. Conclusions P limitation/co-limitation restrict the sexual reproduction of grassland species, which may hamper their dispersal capacity. We recommend future studies further analyze the relationship between soil pH and N:P stoichiometry and the influence of soil pH, as well as soil moisture on sexual reproduction performance of grassland species in addition to analyzing N:P stoichiometry. | Sexual reproduction trait expressions of grassland species along a gradient of nitrogen: phosphorus stoichiometry | 10.1007/s11104-021-05230-2 |
2022-04-01 | Okra ( Abelmoschus esculentus ) has interesting nutritional and technological properties and is naturally gluten-free (GF). This study investigated the physicochemical properties of okra powder obtained by a low-temperature drying process and its impact on GF bread. Its potential synergy with other hydrocolloids (i.e., hydroxypropylmethylcellulose (HPMC) and Psyllium fibre (Psy)) was also studied. As the importance of powder particle size in food design is well known, whole okra powder (WOP; ≤ 1000 µm) and fine okra powder (FOP; ≤ 250 µm) were produced. Compared to the standard formulation, WOP and FOP doughs required less water to reach the desired dough consistency (200 ± 20 Brabender unit) and generally showed higher stability during mixing. Dough development was affected by HPMC more than okra powder particle size. Breads containing WOP or FOP in combination with HPMC exhibited high specific volume and soft texture, while the combination with Psy resulted in a less-developed, harder and darker bread. The combination with HPMC also guaranteed a longer shelf-life, regardless of okra powder particle size. These results may prove useful for the agri-food industry, as they demonstrate that okra can be used as an innovative natural hydrocolloid. | Okra (Abelmoschus esculentus) Powder Production and Application in Gluten-Free Bread: Effect of Particle Size | 10.1007/s11947-022-02784-6 |
2022-04-01 | Renewable energy has become an auspicious alternative to fossil fuel resources due to its sustainability and renewability. In this respect, Photovoltaics (PV) technology is one of the essential technologies. Today, more than 90 % of the global PV market relies on crystalline silicon (c-Si)-based solar cells. This article reviews the dynamic field of Si-based solar cells from high-cost crystalline to low-cost cells and investigates how to preserve high possible efficiencies while decreasing the cost. First, we discuss the various types of c-Si solar cells with different device architectures and report recent developments. Next, thin-film solar cells with their recent advancements are given. Then, Si nanowires solar cells and their recent results are discussed. Finally, we present the most encouraging tendencies in achieving low-cost solar cells utilizing cheap materials like heavily doped silicon wafers. | From Crystalline to Low-cost Silicon-based Solar Cells: a Review | 10.1007/s12633-021-01032-4 |
2022-04-01 | Friction stir processing (FSP) enables surface modifications can likely be applied as a new post-weld treatment for improving fatigue strength. When applying FSP to high-strength materials, tool wear occurring at the interface between the tool tip and the topmost steel layer has been regarded as an unavoidable issue and is related to the tool rotational speed. The present study investigated the relationship between the tool rotational speed and fatigue strength of arc-welded high-strength low-alloy (HSLA) steel joints with weld toes subjected to FSP using a spherical-tip WC tool. FSP was conducted on the weld toe of HSLA steel joints with various tool rotational speeds. Tool wear increased with increase in tool rotational speed, and consequently contents of constituent elements of the WC tool increased in the topmost steel layer of weld toes, leading to large increase in fatigue strength. One reason for the increase with tool rotational speed is significant increase in solid solution hardening due to supersaturated W and C in the topmost steel layer consisting of martensite laths. The hardened topmost steel layer prevented fatigue crack initiation, and the increased fatigue strength depended on the contents of supersaturated W and C. Alloying of the topmost steel layer with tool constituent elements of W and C accompanied with WC tool wear during FSP is unique additive manufacturing to increase the fatigue strength of welded joints, and can be employed locally on structural components susceptible to fatigue. | Fatigue strength improvement due to alloying steel weld toes with WC tool constituent elements through friction stir processing | 10.1007/s00170-022-08690-7 |
2022-04-01 | In this contribution, the notch strain approach is applied to seam welds including butt welds and filet welds. This allows the fatigue assessment for all regimes of fatigue life, including the low cycle fatigue regime ( N > 10). Linear-elastic finite element analyses are used to determine the local stresses. The modeling of the geometry to be assessed is similar to that of the effective notch stress concept. Necessary input values besides linear-elastic stresses are estimated from the hardness of the heat-affected zone. Subsequently, the elastic–plastic stresses and strains are estimated, and a service life calculation is carried out. The used algorithm for the notch strain approach is based on the German FKM-guideline “nonlinear” and includes the influence of stress gradients, highly stressed surfaces, and the influence of surface roughness. Up to now, this FKM-guideline has only been approved for non-welded components. However, this article shows that, with a few modifications, it can also be applied to welds. | Fatigue assessment of weld seams considering elastic–plastic material behavior using the local strain approach | 10.1007/s40194-021-01242-9 |
2022-04-01 | The influence of the initial pH of the solution on ferritization in the Fe 2+ –Co 2+ –SO 4 2− –OH − system was investigated. Cobalt ferrite was obtained by a combined method of co-precipitation and treatment with contact low-temperature non-equilibrium plasma. The pH varied in the range of 7–12. The phase composition was determined by X-ray phase analysis. Magnetic properties by vibration magnetometry. The stability of the formed complexes was evaluated by the cyclic voltammograms method. Studies have shown that PNC treatment promotes ferritization. In this case, by varying the initial pH value, you can get products with different technological characteristics. As the initial pH value increases, the oxidation rate decreases. According to X-ray examination, with increasing initial pH of the suspension, the degree of crystallinity of the final product increases, and the magnetic parameters (saturation magnetization, forced force) also increase rapidly. The formation of cobalt ferrite occurs at an initial pH 11–12 | Investigation of the ferritization process in the Co2+–Fe2+–SO42−–OH− system under the action of contact non-equilibrium low-temperature plasma | 10.1007/s13204-021-01755-1 |
2022-04-01 | Abstract A neutron diffraction study was made of phase transformations in cubic titanium carbide TiC x at the lower boundary of the homogeneity range TiC 0.33 –TiC 0.47 . It was found that the lower boundary of the homogeneity range of the disordered face-centered cubic δ-phase of titanium carbide at 1475 K is at the composition TiC 0.33 . The high-temperature metastable δ-phase in the composition range TiC 0.33 –TiC 0.47 remains structurally stable at T ≤ 800 K. It was shown that the lower boundary of the homogeneity range of the stable ordered cubic single δ'-phase is at the composition Ti 2 C 0.98 . Below this composition, the stable δ'‑phase in the composition range Ti 2 C 0.66 –Ti 2 C 0.94 was observed in equilibrium with α-Ti, which suggested that the lower boundary of the homogeneity range of the stable δ'-phase is at the composition Ti 2 C 0.66 . In the equilibrium state, the degree of long-range order and the size of antiphase domains in the δ'-phase increase with decreasing carbon content. | Neutron Diffraction Study of Phase Transformations at the Lower Boundary of the Homogeneity Range of Cubic Titanium Carbide TiCx | 10.1134/S0036023622040106 |
2022-04-01 | Recent advancements in wireless communication systems utilize miniaturized devices based on microelectromechanical system technology for present and future 5G wireless applications. Nowadays, RF devices are utilizing frequencies up to 30 GHz with substantial signal propagation that leads to a slow data rate. On the other hand, there is a huge spectrum available in the millimeter-wave frequency range of 30–300 GHz. The millimeter-wave spectrum is attractive for the development of smart systems based on 5G technology. In this paper, a low-pull-in-voltage capacitive type RF MEMS switch is proposed to operate at frequencies above 30 GHz. The switch is proposed with a new iterative meandering technique where the span length of each section in the meanders differs relative to the first section. A low pull-in voltage of 1.8 V is achieved with a large capacitance ratio of 63. The switch exhibits low insertion loss of −0.24 dB at 41 GHz and possesses high isolation of −46.7 dB at 38 GHz. The design is validated by comparing the theoretical and simulated results, and the switch can be efficiently utilized for millimeter-wave applications. | Design and performance analysis of a low-pull-in-voltage RF MEMS shunt switch for millimeter-wave therapy, IoT, and 5G applications | 10.1007/s10825-022-01863-3 |
2022-04-01 | Pollutants found in the wastewater streams of industrial processes such as heavy metals are a significant concern worldwide. Clays are low-cost sorbents that have attracted extensive research interest due to their potential applications in removing heavy metals from wastewater. In this work, montmorillonite clay was collected from the Bengurir region; Morocco was used as an eco-friendly adsorbent for the removal of chromium (III) at various operating conditions. The used adsorbent was characterized using X-ray diffraction, X-ray fluorescence spectrometry, Fourier Transform Infrared Spectroscopy, and scanning electron microscope coupled with X-ray energy dispersion spectrometer analysis. Effects of adsorbent dose, initial concentration, and pH were investigated to optimize the adsorption process. The controlling mechanism and the potential rate-limiting steps were analyzed using Lagergren’s pseudo-first-order and pseudo-second-order models, but the experimental data were better fitted to the pseudo-second-order equation. The equilibrium isotherm data were analyzed by applying Langmuir and Freundlich’s isotherm models, and Langmuir showed good fits with the experimental data. A maximum Cr(III) adsorption capacity of 7.5 mg g −1 was found in the studied conditions. | Green and eco-friendly montmorillonite clay for the removal of Cr(III) metal ion from aqueous environment | 10.1007/s13762-021-03303-4 |
2022-04-01 | Earthquake-induced fractures in steel structures are characterised by high-strain low-cycle conditions. In order to investigate the ultra-low cyclic fatigue fracture of steel welded joints under earthquakes, two most commonly used structural steels (Q235B and Q345B) and the corresponding welds were studied by experiments and numerical analysis in this paper. Specimens were extracted from the base material, the weld metal and the heat affected zone to investigate the behaviour in different parts of the welded joint. Eighteen smooth round bars were tested under large strain amplitudes, the hysteretic properties, damage degradation characteristics and failure process were analyzed. Constitutive model named Chaboche model was calibrated to describe the cyclic hardening behaviour of these materials. Seventy-two notched round bars with three different notch sizes and two loading protocols were tested to study the fracture behaviour of different materials at different stress triaxialities and different strain amplitudes. Two micromechanical fracture models: cyclic void growth model and degraded significant plastic strain model were calibrated based on the test results. The micromechanical models and Chaboche model were incorporated into numerical simulations by software ABAQUS with subroutine VUMAT to predict the materials fracture. The results show that the failure process under cyclic loads is opposite to that of monotone loads. The dissipation capacity of Q345B is superior to that of Q235B. The fracture resistance deteriorate more in the weld zone under the same loading conditions. The validated models can be used to effectively and accurately evaluate the fracture in steel welded connections under ULCF conditions. | Ultra-Low Cyclic Fatigue Fracture of Q235B and Q345B Steels and Their Butt Welded Joints | 10.1007/s13296-022-00583-5 |
2022-04-01 | The predictability of the Northern Hemisphere stratosphere and its underlying dynamics are investigated in five state-of-the-art seasonal prediction systems from the Copernicus Climate Change Service (C3S) multi-model database. Special attention is devoted to the connection between the stratospheric polar vortex (SPV) and lower-stratosphere wave activity (LSWA). We find that in winter (December to February) dynamical forecasts initialised on the first of November are considerably more skilful than empirical forecasts based on October anomalies. Moreover, the coupling of the SPV with mid-latitude LSWA (i.e., meridional eddy heat flux) is generally well reproduced by the forecast systems, allowing for the identification of a robust link between the predictability of wave activity above the tropopause and the SPV skill. Our results highlight the importance of November-to-February LSWA, in particular in the Eurasian sector, for forecasts of the winter stratosphere. Finally, the role of potential sources of seasonal stratospheric predictability is considered: we find that the C3S multi-model overestimates the stratospheric response to El Niño–Southern Oscillation (ENSO) and underestimates the influence of the Quasi–Biennial Oscillation (QBO). | Seasonal prediction of the boreal winter stratosphere | 10.1007/s00382-021-05787-9 |
2022-04-01 | In this article, a distinctive charge plasma (CP) technique is employed to design two doping-less dual gate tunnel field effect transistors (DL-DG-TFETs) with Si 0.5 Ge 0.5 and Si as source material. The CP methodology resolves the issues of random doping fluctuation and doping activation. The analog and RF performance has been investigated for both the proposed devices i.e. Si 0.5 Ge 0.5 source DL-DG-TFET and Si-source DL-DG-TFET in terms of drive current, transconductance, cut-off frequency. In addition, the linearity and distortion analysis has been carried out for both the proposed devices with respect to higher order transconductance (g m2 and g m3 ), VIP2, IMD3, and HD2. The Si 0.5 Ge 0.5 source DL-DG-TFET has better performance characteristics and reliability in compare to Si-source DL-DG-TFET owing to low energy bandgap material and higher mobility. The switching ratio obtained for Si 0.5 Ge 0.5 source DL-DG-TFET is order of 5 × 10 14 that makes it a suitable contender for low power applications. | A SiGe-Source Doping-Less Double-Gate Tunnel FET: Design and Analysis Based on Charge Plasma Technique with Enhanced Performance | 10.1007/s12633-021-01030-6 |
2022-04-01 | Hybridization of inherently brittle carbon fibers with basalt fibers in the fiber reinforced plastics results in improved impact damage resistance and ductility. This study investigates the effects of two hybridization types i.e., interply and intraply and compares the tensile, dynamic, and quasi-static loading behavior of the carbon/basalt hybrid composites. While low velocity impact (LVI) tests were conducted at rebounding, penetrating and perforating impact velocities of 4, 5.6 and 6.6 ms −1 , quasi-static indentation was monitored by acoustic emission signals to estimate the types of failures produced during the loading. Various parameters deduced from the experimental data were correlated with the structural configurations. Results showed that the type of hybridization and location of constituent fibers influenced the peak fracture forces, overall laminate ductility and damage degree. While the tensile strength and percent elongation of the intraply hybrid was higher, interply hybrids showed comparatively better damage absorption. Higher tensile strength and lower damage absorption in the intraply hybrids was a result of better interlayer cohesion and types of failure modes in the carbon yarns, respectively. In the interply hybrids, compliant deformation of basalt fibers and delamination of ductile fabric type interfaces improved the damage absorption of the laminate. | Comparison of Static/Dynamic Loading and Tensile Behavior of Interply and Intraply Hybridized Carbon/Basalt Epoxy Composites | 10.1007/s10443-021-09973-0 |
2022-04-01 | With the gradually prominent contradiction among economic growth, resources, and the environment, low-carbon competitiveness has become the focus of world attention. This study is aimed at exploring the low-carbon competitiveness of a low-carbon pilot city in China. This study constructed an evaluation index system of low-carbon competitiveness with 40 indicators based on DPSIR (Drivers (D)–Pressure (P)–State (S)–Impact (I)–Response (R)) model, determined indicators’ weights by Game Theory method, evaluated low-carbon competitiveness combined with TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method, and analyzed spatiotemporal differences of the study area. The DPSIR–Game Theory Combination Weighting–TOPSIS approach is put forward, which is an overall method to carry out calculations on indicator weights, and it is especially appropriate to assess burgeoning fresh objects. On the basis of the DPSIR–Game Theory Combination Weighting–TOPSIS approach, spatiotemporal differences of low-carbon competitiveness from 2008 to 2017 in Guiyang were compared and analyzed. The state of low-carbon competitiveness had been improved from a weak level to a medium and strong level during 2008 to 2017. However, there was still a big gap compared with the stronger low-carbon competitiveness. In addition, some policies and suggestions are put forward to promote low-carbon competitiveness development, hoping to provide references for the decision making of local governments and provide theoretical supports for low-carbon construction in other countries. | Evaluating low-carbon competitiveness under a DPSIR-Game Theory-TOPSIS model—A case study | 10.1007/s10668-021-01680-x |
2022-04-01 | The purpose of this study was to optimize the conditions of the gas–metal arc welding using CO 2 shield gas (CO 2 arc welding) with hot-wire feeding technology. A high-speed camera was used to investigate welding phenomena of a butt joint of 36-mm-thick steel plates. The optimum parameters were determined under combinations of the welding current (300 or 400 A) and hot-wire feeding speed (0 to 12.5 m/min) to avoid molten metal precedence. A sound joint was achieved with only four weld passes using optimum conditions. Adequate joint properties, including tensile strength and toughness, were obtained. The optimum conditions provided a welding process with both high efficiency and low heat input. | Optimization of welding conditions for hot-wire GMAW with CO2 shielding on heavy-thick butt joint | 10.1007/s40194-021-01227-8 |
2022-04-01 | Fuel poverty is most prevalent in North East England with 14.4% of fuel poor households in Newcastle upon Tyne. The aim of this paper was to identify a grid connected renewable energy system coupled with natural gas reciprocating combined heat and power unit, that is cost-effective and technically feasible with a potential to generate a profit from selling energy excess to the grid to help alleviate fuel poverty. The system was also aimed at low carbon emissions. Fourteen models were designed and optimized with the aid of the HOMER Pro software. Models were compared with respect to their economic, technical, and environmental performance. A solution was proposed where restrictions were placed on the size of renewable energy components. This configuration consists of 150 kW CHP, 300 kW PV cells, and 30 kW wind turbines. The renewable fraction is 5.10% and the system yields a carbon saving of 7.9% in comparison with conventional systems. The initial capital investment is $1.24 million which enables the system to have grid sales of 582689 kWh/a. A conservative calculation determined that 40% of the sales can be used to reduce the energy cost of fuel poor households by $706 per annum. This solution has the potential to eliminate fuel poverty at the site analyzed. | Fuel poverty and low carbon emissions: a comparative study of the feasibility of the hybrid renewable energy systems incorporating combined heat and power technology | 10.1007/s11708-021-0748-x |
2022-04-01 | Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface and hand disinfection with a disinfectant to avoid viral transmission. The detection of coronaviruses on surfaces implies not always a high danger of infection. Different coronaviruses and SARS-CoV-2 can be detected under experimental conditions on surfaces for many days. However, there are no studies concerning the virus load and the risk for an infection. The aim of our study was to find out if we could detect SARS-CoV-2 with a virus load greater than 10 6 copies/mL in public areas under real-life conditions. A total of 1200 swabs were performed on different environmental surfaces in public areas: handholds, press buttons in buses, tramways, tubes, elevators, shops, doorknobs in public buildings, public restrooms, touchscreens in shops and public transportation services, supermarket trolleys, banknotes and coins and immediately tested. We used Rapid Covid-19 Antigen Test (Clinitest®) by Siemens Healthineers (Healgen Scientific Limited Liability Company, Houston, USA, respectively, Shanghai International Holding Corp. GmbH (Europe), Hamburg, Germany). During our study, we were not able to detect SARS-CoV-2 with a virus load greater than 10 6 copies/ml although we pooled the swabs. According to the negative antigen tests and with a theoretically probability calculation of 1/24.000, there seems no relevant risk of infection with SARS-CoV-2 in public areas. For people with underlying diseases or immunosuppression, the risk of transmission respectively infectivity cannot be excluded with this study. | SARS-CoV-2: low virus load on surfaces in public areas | 10.1007/s11356-022-18514-6 |
2022-04-01 | For safe operation of active space crafts, the space debris population needs to be continuously scanned, to avoid collisions of active satellites with space debris. Especially the low Earth orbit (LEO) shows higher risks of collisions due to the highest density of orbital debris. Laser ranging stations can deliver highly accurate distance measurements of debris objects allowing precise orbit determination and more effective collision avoidance. However, a laser ranging station needs accurate a priori orbit information to track an orbital object. To detect and track unknown orbital objects in LEO, here, a passive optical staring system is developed for autonomous 24/7 operation. The system is weather-sealed and does not require any service to perform observations. To detect objects, a wide-angle imaging system with 10° field of view equipped with an astronomical CCD camera was designed and set up to continuously observe the sky for LEO objects. The system can monitor and process several passing objects simultaneously without limitations. It automatically starts an observation, processes the images and saves the 2D angular measurements of each object as equatorial coordinates in the TDM standard. This allows subsequent initial orbit determination and handover to a laser tracking system. During campaigns at twilight the system detected up to 36 objects per hour, with high detection efficiencies of LEO objects larger than 1 m 3 . It is shown that objects as small as 0.1 m 3 can be detected and that the estimated precision of the measurements is about 0.05° or 7 × the pixel scale. | APPARILLO: a fully operational and autonomous staring system for LEO debris detection | 10.1007/s12567-021-00380-6 |
2022-04-01 | Adsorption characteristics of CO 2 –CH 4 –H 2 O-coal matrix systems are extremely important for investigating geological CO 2 -storage and enhanced coalbed methane recovery. To study the adsorption mechanism of CH 4 and CO 2 under the equilibrium water state, this study conducted high-pressure mercury intrusion porosimetry, low-temperature N 2 adsorption, and high-pressure methane isothermal adsorption of CH 4 and CO 2 on coal samples under equilibrium water condition. From these experimental results, the parameters including Gibbs free energy change ( ΔG ), entropy change ( ΔS ), maximum adsorption volume, selectivity coefficient ( α ) and Henry’s constant ( K H ) were extracted to discuss the influence of moisture on the CH 4 and CO 2 adsorption behavior of low-rank coals. The results show that water in low-rank coal had an “inhibitory effect” on the adsorption of CH 4 and CO 2 . The maximum theoretical adsorption capacity of CO 2 ( a 2 ) in each coal sample was greater than that of CH 4 ( a 1 ), and the absolute value of the CO 2 entropy change ( ΔS 2 ) was greater than that of the CH 4 entropy change ( ΔS 1 ), indicating that low coal-rank coals had higher adsorption capacity of CO 2 than that of CH 4 . For the equilibrated-water isothermal adsorption results, the differential adsorption of CH 4 and CO 2 was due to differences in coal maceral compositions and the development of micro- and meso-pores in different coals. It was concluded that CO 2 enhanced coalbed methane technology has better application potential in low-rank coal reservoirs than in medium-to-high rank coal reservoirs. | CH4 and CO2 Adsorption Characteristics of Low-Rank Coals Containing Water: An Experimental and Comparative Study | 10.1007/s11053-022-10026-x |
2022-04-01 | Abstract The effect of low-frequency plasma treatment of chitosan films on the surface chemical structure, morphology, and properties, including the ability to support adhesion and the proliferation of human keratinocytes, was evaluated. It was shown that plasma treatment led to the formation of polar oxygen-containing groups on the surface, a decrease in surface roughness, and an increase in surface hydrophilicity. The chitosan film samples were cytocompatible, and they maintained keratinocyte viability when used as extracts or as supports for cell cultivation. Plasma treatment of chitosan films increased their adhesion properties with respect to cells and activated keratinocyte proliferation, which is important for the application of chitosan-containing materials as a wound dressing. | Modification of the Chemical Structure, Morphology, and Cytocompatibility of Chitosan Films via Low-Frequency Plasma Treatment | 10.1134/S000368382202003X |
2022-04-01 | Textile industry, a major trade in most developing countries, generates huge quantities of dye laden wastewater. Azo dyes, which are still used widely in textile industry are very toxic in nature and need to be removed from the wastewaters in a cost-effective manner. The conventional treatment methods are energy intensive and costly, making it necessary to explore low-cost methods for developing countries. The present study explores the potential application of an indigenous alkaliphilic bacterium Nesterenkonia lacusekhoensis EMLA3 for decolorizing eleven different types of azo dyes (Methyl red, Tartrazine, Ponceau S, Reactive red 35, Evans blue, Acid red 3R, Acid red, Violet C BL, Reactive violet, Red AG and Methyl orange) at high pH of wastewater. The strain showed remarkable ability to decolorize more than 90% of these azo dyes (100 mg l −1 each) within 72 to 192 h through biodegradation in nutrient medium. The bacterium showed good growth (in terms of absorbance at 600/660 nm in the presence of the dyes indicating its tolerance toward these pollutants. The bacterium not just decolorized dye mixture at high pH in presence of indigenous microorganisms of wastewater, but also decreased Chemical Oxygen Demand (COD). It gradually lowered pH of the wastewater from initial 11.0 to 8.4 during the treatment. The microbially treated textile wastewater when tested for seed germination and growth of Vigna radiata showed no phytotoxicity. Use of this indigenous microbe thus opens new opportunities for treating dye containing wastewaters in an ecofriendly and economic manner. | Using indigenous bacterial isolate Nesterenkonia lacusekhoensis for removal of azo dyes: A low-cost ecofriendly approach for bioremediation of textile wastewaters | 10.1007/s10668-021-01661-0 |
2022-04-01 | The link performance of free space optical communications (FSOC) and deep space optical communications (DSOC) are investigated by considering two scenarios in space communications, for example, for the downlink and uplink between the earth ground stations and the near earth geostationary (GEO) satellites, and between the earth and spacecraft with large distance of 1 astronomical unit (AU) to the earth. Generally a distance larger than 0.01 AU or approximately 1,500,000 km from Earth is considered as deep space. In these theoretical investigations, different realistic system parameters for the optical lasers, transmitters, receivers, avalanche photodiodes (APDs), optical telescopes, atmospheric disturbances like scintillation and absorption are considered. The simulation results are compared with existing project data and valuable ESA experimental results to verify and improve the simulation models. The comparison in this paper shows that the simulation models for the link budget and the scintillation estimation are feasible for the investigations of FSOC and DSOC, and can be used to investigate improved design and implementation of DSOC projects for planned long-term and medium-term space missions. | Investigations of free space and deep space optical communication scenarios | 10.1007/s12567-021-00388-y |
2022-04-01 | The colorful, unfading, and eco-friendly photonic crystal structural colors have attracted wide interest from textile researchers. However, to minimize the interference of incoherently scattered light, the preparation of the structural color fabric is still based on the black fabric, which seriously restricts the practical application of the structural colors in textile dyeing and finishing. This paper presented a straightforward strategy to construct structural colors on the fabrics by assembling polysulfide microspheres (PSMs) with self-absorbing light properties. The monodisperse PSMs were successfully synthesized through a polycondensation process between Na 2 S 2 and 1,2,3-trichloropropane, whose particle size can be controlled by adjusting the volume ratio of ethanol-water. Four different structural colors were successfully obtained on white polyester fabric by varying the diameter of the PSMs arranged on the fabric surface in a face-centered cubic structure. Notably, the designed structural color fabrics had a low angle dependence, which was more meaningful for the textile color measuring and matching system. | Preparation of Structural Colors on White Polyester Fabrics without Adding Any Black Additive | 10.1007/s12221-022-4548-7 |
2022-04-01 | Cold-adapted bacterial strains are potentially valuable for biotechnological applications involving the production of cold-active enzymes and bioproducts important to various industries. A psychrotolerant, aerobic, Gram-positive, endospore-forming, bioemulsifier-producing strain, named Val9, was isolated from Vale Ulman soil samples, King George Island, Antarctica and identified as a member of the genus Psychrobacillus . To better characterize this novel strain, its whole genome was sequenced revealing a size of 3,986,526 bp with a G + C content of 36.6%, and 4042 predicted coding DNA sequences (CDSs). Digital DNA–DNA hybridization (dDDH) and average nucleotide identity (ANI) analyses between strain Val9 and the type strains of the seven Psychrobacillus species revealed that the highest values were observed with Psychrobacillus psychrodurans DSM11713 T but below the conventional thresholds of 70% dDDH and 95% ANI for bacterial species assignment, suggesting that strain Val9 could represent a distinct species. As potential low-temperature adaptation strategies, genes encoding cold shock proteins, transporters for glycine-betaine, carnitine and choline, and enzymes acting against oxidative stress were found in Val9 genome. DEAD-box RNA helicases, important for cold and oxidative tolerance, and a two-component signal transduction system related to plasmatic membrane fluidity as well as biotechnologically important CDSs, related to levan production, were detected. The sacB gene encoding the enzyme levansucrase was exclusive for Val9 and it was not found in the other Psychrobacillus type strains. Altogether, the comparative genomic analyses presented here highlight important metabolic pathways and the biotechnological potential of this novel strain. | Genomic analyses of a novel bioemulsifier-producing Psychrobacillus strain isolated from soil of King George Island, Antarctica | 10.1007/s00300-022-03028-1 |
2022-04-01 | Water injection is an effective method for developing low permeability sandstone reservoirs. In the process of water flooding, reservoir damage can occur due to clay mineral content changes and it will significantly affect oil production. There are few investigations on the changes in clay mineral content and the degree of reservoir damage after injecting the water into low permeability sandstone reservoirs with different permeabilities and lithologies. In this study, low permeability natural cores from different lithological strata were collected from 4 wells in the Daqing sandstone reservoir, and clay mineral components and contents were measured through X-ray diffraction. Changes in the clay mineral content were determined after water injection. The reservoir damage mechanism by clay mineral migration was determined by analyzing scanning electron microscopy (SEM) images after water injection. Meanwhile, the porosity and permeability of the cores were tested after water injection, and the degree of reservoir damage in different lithological strata was determined. The clay mineral content ranges from 6.78 to 14.14% in low permeability sandstone cores and declines by 49.73% after water flooding. Illite, chlorite and illite/smectite mostly decrease, and kaolinite decreases the least. Due to the large particle size of kaolinite, kaolinite migration will block the pore-throats and cause formation damage after water flooding. In argillaceous siltstone and siltstone, kaolinite particles blocking pore-throats are very serious, and the permeability decreases greatly by 21.87–36.89% after water injection. With increasing permeability, the permeability decreases greatly after water injection. The findings of this study can help to better understand the mechanisms of formation damage after injecting water into low permeability sandstone reservoirs. | Experimental investigation on reservoir damage caused by clay minerals after water injection in low permeability sandstone reservoirs | 10.1007/s13202-021-01356-2 |
2022-04-01 | Assessing exposure to ambient fine particulate matter (PM 2.5 ) is important for improving human health. With rapidly expanding low-cost sensor networks globally, it is possible for monitoring networks to be located by a variety of users (i.e., crowd sourcing) to increase measurement density and coverage for use in exposure assessment, e.g., national land use regression (LUR) models. Few studies have integrated low-cost sensors into LUR models across multiple cities, limiting the ability of modelers to fully utilize growing low-cost sensor networks worldwide. We developed five LUR models to predict annual average PM 2.5 concentrations using combinations of regulatory (six cities: n = 68; national: n = 757) and low-cost monitors ( n = 149) from six US cities. We found that developing Hybrid LURs that include the low-cost (i.e., PurpleAir) network may better capture within-city variation. LURs with the PurpleAir data only (tenfold CV R 2 = 0.66, MAE = 2.01 µg/m 3 ) performed slightly worse than a conventional LUR based on regulatory data only (tenfold CV R 2 = 0.67, MAE = 0.99 µg/m 3 ). Hybrid models that included both low-cost and regulatory data performed similarly to existing national models that rely on regulatory data (hybrid models: tenfold CV R 2 = 0.85, MAE = 1.02 µg/m 3 ; regulatory monitor models: R 2 = 0.83, MAE = 0.72 µg/m 3 ). Integrating crowd-sourced low-cost sensor networks in LUR models has promising applications to help identify intra-city exposure patterns especially for regions with limited regulatory networks internationally. | Using crowd-sourced low-cost sensors in a land use regression of PM2.5 in 6 US cities | 10.1007/s11869-022-01162-7 |
2022-04-01 | Research on nanocrystals is rapidly finding applications in energy, medical and agricultural fields. In particular, improving nanocrystal activity should improve hydrogen generation by photocatalytic water splitting. While nanocrystal activity is classically changed by modifying crystal size and by surface coating, modifying crystal structure by facet engineering is rising to control nanocrystal functionality. For instance, low-index faceted nanocrystals are easily obtained and are commonly represented by Miller indices { hkl } with at least one index value equal to unity or zero. Low-index facets improve the photocatalytic performance of water splitting and pollutants transformation. Here we review low-index facet-dependent photocatalytic activity and the environmental impact of metal-based nanocrystals. We found that photocatalytic activity and environmental impact are highly dependent on the specific exposed facet. The effect of shape on nanocrystal functionality is mainly due to the exposed facet. | Water splitting, pollutant degradation and environmental impact using low-index faceted metal-based nanocrystals. A review | 10.1007/s10311-021-01385-7 |
2022-04-01 | Within the hazard and disaster risk research field, explicitly treating carbon emissions as a hazard remains rather nascent. Applying hazard and disaster risk research perspectives to seek new insights on integrated mitigation and adaptation approaches and policy measures is equally elusive. Since China’s pledge to achieve carbon neutrality by 2060, the “dual carbon” goals of carbon emission peaking and neutrality have stimulated nationwide attention, research, and policies and action plans. How to ensure that the transition pathways are on track and well-contextualized is one of the crucial challenges for policymakers and practitioners. This article examines the “risks” of missing the carbon neutrality goal at a regional scale in China, denoted as Carbon Emission Risk (CER). Carbon emissions (CE) as hazard, combined with the human socioeconomic system as exposure and human living environment, constitute the regional carbon emission environmental risk system. The “risks” of missing (or achieving) the carbon neutrality target for any region at any time, the article argues, is essentially determined by the ratio of CE to carbon absorption (CA, for uptake and removal). These variables are modified by a broadly defined “vulnerability coefficient” (Cv) that embodies both the potential for changes (decreasing CE and increasing CA), and the uncertainties of measuring CE and CA. Thus, the ratio of CE to CA is a measure of reality at any moment of time, whereas Cv indicates the overall propensity or capacity for moving the CE/CA ratio towards 1, that is, realizing carbon neutrality. Based on our calculation, CER at the provincial level in eastern China is higher than in western China. The article also calls for strengthening CER research and summarizes key measures for carbon emission risk governance. | Carbon Emission Risk and Governance | 10.1007/s13753-022-00411-8 |
2022-04-01 | The specific surface and porosity of bituminous coal (rank Zh) are studied. The textural characteristics of Kuznetsk Basin coal are determined by various methods: for example, the specific surface by the Brunauer–Emmett–Teller (BET) method; the micropore volume by the comparative t -plot method; and the mesopore volume by the Barrett–Joyner–Halenda method from the low-temperature (77 K) absorption–desorption isotherms obtained by means of a Micromeritics ASAP 2020 instrument. The specific surface is small, and mesopore structure predominates for all the coal samples. Analysis of the pore structure of Kuznetsk Basin coal reveals their macro- and microstructure and provides information regarding their adsorption properties. | Texture of Bituminous Kuznetsk Basin Coal | 10.3103/S1068364X22040032 |
2022-04-01 | Purpose Low-grade gliomas (LGG) and mixed neuronal-glial tumors (MNGT) show frequent MAPK pathway alterations. Oncogenic fibroblast growth factor receptor 1 (FGFR1) tyrosinase kinase domain has been reported in brain tumors of various histologies. We sought to determine the frequency of FGFR1 hotspot mutations N546 and K656 in driver-unknown LGG/MNGT and examined FGFR1 immunohistochemistry as a potential tool to detect those alterations. Methods We analyzed 476 LGG/MNGT tumors for KIAA-1549-BRAF fusion, IDH1/2, TERT promotor, NF1, H3F3A and the remaining cases for FGFR1 mutation frequency and correlated FGFR1 immunohistochemistry in 106 cases. Results 368 of 476 LGG/MNGT tumors contained non-FGFR1 alterations. We identified 9 FGFR1 p.N546K and 4 FGFR1 p.K656E mutations among the 108 remaining driver-unknown samples. Five tumors were classified as dysembryoplastic neuroepithelial tumor (DNT), 4 as pilocytic astrocytoma (PA) and 3 as rosette-forming glioneuronal tumor (RGNT). FGFR1 mutations were associated with oligodendroglia-like cells, but not with age or tumor location. FGFR1 immunohistochemical expression was observed in 92 cases. FGFR1 immunoreactivity score was higher in PA and DNT compared to diffuse astrocytoma, but no correlation between FGFR1 mutation in tumors and FGFR1 expression level was observed. Conclusion FGFR1 hotspot mutations are the fifth most prevailing alteration in LGG/MNGT. Performing FGFR1 sequencing analysis in driver-unknown low-grade brain tumors could yield up to 12% FGFR1 N546/K656 mutant cases. | Frequent FGFR1 hotspot alterations in driver-unknown low-grade glioma and mixed neuronal-glial tumors | 10.1007/s00432-021-03906-x |
2022-04-01 | The addition of Ni element into steel to prolong the service life of coated steel was investigated in marine atmospheric environment by laboratory simulated accelerated experiment. The scanning electron microscope and electron probe micro-analysis combined with electrochemical impedance spectroscopy were used to characterize coated steel properties and examined the anti-corrosion performance. The results showed that 3 wt.% Ni-advanced steel (3Ni steel) substrate obviously delayed the failure time of coating compared to carbon steel, therefore prolonging the service life of coating on the steel. X-ray diffraction patterns for the corrosion products under the scratched coating on 3Ni steel exhibited that FeNi 2 O 4 and Fe 2 O 3 occurred in the corrosion product of 3Ni steel. It was also found that Ni element enriched in the product layer through analyzing the appearance and composition of corrosion products by electron probe micro-analysis. Chloride ions were blocked out of product by the enrichment of Ni element in rust layer. | Evaluation of increasing service life of epoxy zinc-rich coating on 3 wt.% Ni-advanced low-alloy steel in marine atmospheric environment | 10.1007/s42243-021-00661-8 |
2022-04-01 | High maternal serum estradiol (E 2 ) levels in the first trimester of pregnancy are associated with a high incidence of low birth weight (LBW) and small for gestational age (SGA). This study aimed to investigate the effect of first-trimester high maternal serum E 2 levels on fetal growth and the underlying mechanisms in multiple pregnancies. Maternal serum E 2 levels of women at 8 weeks of gestation were measured. The expression levels of imprinted genes and DNMT1 were determined by RT-qPCR, and KvDMR1 methylation in embryo tissue, placenta, and newborn cord blood samples was examined by bisulfite sequencing PCR. The effect of E 2 on CDKN1C expression was investigated in HTR8 cells. The incidence of SGA was significantly higher in multiple pregnancies reduced to singleton than that in primary singleton pregnancies (11.4% vs. 2.9%) ( P < 0.01) and multiple pregnancies reduced to twins than primary twins (38.5% vs. 27.3%) ( P < 0.01). The maternal serum E 2 level at 8 weeks of gestation increased with the number of fetuses and was negatively correlated with offspring birth weight. CDKN1C and DNMT1 expression was significantly upregulated in embryo tissue, placenta, and cord blood from multiple pregnancies. Furthermore, there was a positive correlation between CDKN1C mRNA expression and KvDMR1 methylation levels. In HTR8 cells, DNMT1 mediated the estrogen-induced upregulation of CDKN1C , which might contribute to SGA. To minimize the risks of LBW and SGA, our findings suggest that abnormally high maternal serum E 2 levels should be avoided during the first trimester of multiple pregnancies from assisted reproductive technology (ART). | High Maternal Serum Estradiol in First Trimester of Multiple Pregnancy Contributes to Small for Gestational Age via DNMT1-Mediated CDKN1C Upregulation | 10.1007/s43032-021-00735-8 |
2022-04-01 | Functional bacterial enrichment magnetic beads (Fe 3 O 4 @SiO 2 @Fc-MBL) and Gram staining were combined for the fast diagnosis of infecting bacteria in meningitis. Fe 3 O 4 @SiO 2 @Fc-MBL has excellent microbial binding ability and can be used for bacterial enrichment from cerebrospinal fluid (CSF). The enriched bacteria are recognized by Gram stain at very low concentrations (10 CFU·mL −1 ). The feasibility of this method was verified by five common bacteria in meningitis infection (Gram-positive: Staphylococcus epidermidis , Staphylococcus haemolyticus , and Staphylococcus capitis ; Gram-negative: Klebsiella pneumoniae and Escherichia coli ). The extraction efficiency of Fc-MBL-modified Fe 3 O 4 magnetic beads was approximately 90% in artificial CSF for the selected bacteria, with the exception of E. coli (~ 60%). The bacteria were successfully recognized by Gram staining and microscopic observation. Fe 3 O 4 @SiO 2 @Fc-MBL acts by capturing and fixing the bacteria in a magnetic field throughout the experiment. Compared with traditional CSF Gram staining, this new method avoids interference by inflammatory cells and red blood cells during microscopic examination. Furthermore, the sensitivity of this method is much better than the centrifugation smear method. The whole process can be accomplished within 30 min. This novel method may have potential as a clinical tool for analysis of bacteria in the CSF. Graphical abstract | Fc-MBL-modified Fe3O4 magnetic bead enrichment and fixation in Gram stain for rapid detection of low-concentration bacteria | 10.1007/s00604-022-05277-7 |
2022-04-01 | In the present study, Fe-based metallic glass composite coatings were synthesized by using two different low-Cr and inexpensive alloying elements containing compositions of Fe 73 Cr 2 Si 11 B 11 C 3 , at. % (P1) and Fe 63 Cr 9 P 5 B 16 C 7 , at. % (P2) to investigate their wear and corrosion properties. The coatings were synthesized under optimum spraying parameters via atmospheric plasma spraying (APS), and microstructural characterization showed that the coatings were dense (porosity < 5%) and primarily consisted of amorphous phase (amorphicity level > 84%). Interestingly, corrosion resistance of the P1 powder-based coating was comparable to high-Cr containing plasma-sprayed stainless steel (SS316L) coating despite very low Cr content, which is ascribed to the higher level of amorphicity. The P2-based coating exhibited superior corrosion resistance, attributed to a better combination of lower porosity (~3.3%), the presence of amorphous phase and formation of higher amount of protective α-CrOOH and Fe 2−x Cr x O 3 . Both the coatings exhibited higher wear resistance compared to the stainless steel coating. Nonetheless, P2-based coating displayed better anti-wear behavior, which was ascribed to its denser microstructure and presence of relatively higher content of hard Fe-based intermetallics. P2-based coating displayed higher value of wear property parameter (H/E r , 0.073), lower specific wear rate (6.1 × 10 -6 mm 3 /Nm) and lower coefficient of friction (0.13), signifying excellent wear resistance. Graphical Abstract | Comparative Study on Wear and Corrosion Behavior of Plasma Sprayed Fe73Cr2Si11B11C3 and Fe63Cr9P5B16C7 Metallic Glass Composite Coatings | 10.1007/s11666-021-01280-1 |
2022-04-01 | Internet connects people to people, people to machine, and machine to machine for a life of serendipity through a Cloud. Internet of Things networks objects or people and integrates them with software to collect and exchange data. The Internet of things (IoT) influences our lives based on how we ruminate, respond, and anticipate. IoT 2021 heralds from the fringes to the data ecosystem and panaches a comfort zone. IoT is overwhelmingly embraced by businessmen and consumers due to increased productivity and convenience. Internet of Things facilitates intelligent device control with cloud vendors like Amazon and Google using artificial intelligence for data analytics, and with digital assistants like Alexa and Siri providing a voice user interface. Smart IoT is all about duplex connecting, processing, and implementing. Centralized IoT architecture is vulnerable to cyber-attacks. With Block Chain, it is possible to maintain transparency and security of the transaction's data. Robotic Process Automation (RPA) using bots has automated laborious tasks in 2019. Embedded Internet using Facial Recognition could reduce the coronavirus pandemic crisis by making a paradigm shift from fingerprint sensors to facial recognition. Security concerns are addressed with micro-segmentation approaches. IoT, an incredible vision of the future makes systems adaptive with customized features, responsive with increased efficiency, and procurable with optimized cost. This research delivers a comprehensive insight into the technical perspectives of IoT, focusing on interoperability, flexibility, scalability, mobility, security, transparency, standardization, and low energy. A smart classroom is implemented based on the concepts of IoT. | Decades of Internet of Things Towards Twenty-first Century: A Research-Based Introspective | 10.1007/s11277-021-09308-z |
2022-04-01 | Abstract— The paper presents original data on the composition of hydrocarbon biomarkers and the carbon isotope composition of fractions of some oils in the Middle Devonian–lower Frasnian terrigenous rock complex in the Timan–Pechora basin. The oils typically contain high concentrations of paraffin hydrocarbons. The oils of hydrocarbon systems were generated at the catagenesis of terrigenous organic matter in the host rocks. The complex of hydrocarbon biomarkers of the oils shows features indicating that the paraffin-rich dominant component of the oils mixed with oils from other hydrocarbon systems, namely, from the Domanik–Tournaisian and Lower Paleozoic carbonate rock complexes. | Geochemistry of Oils in the Middle Devonian–Lower Frasnian Terrigenous Petroleum System of the Timan–Pechora Basin | 10.1134/S0016702922030028 |
2022-04-01 | The purpose of this study was to systematically review the scientific evidence of the effect of low-level laser therapy (LLLT) on the perception of pain, edema, and trismus after orthognathic surgery. The literature was searched in 11 databases (MedLine via PubMed, Scopus, LILACS, SciELO, Embase, Web of Science, Cochrane Library, and LIVIVO, OpenGrey, OADT, and OpenThesis), without restriction of publication year or language. This search aimed to identify randomized clinical trials comparing low-level laser therapy and placebo for controlling pain, edema, and trismus after orthognathic surgeries. Two reviewers extracted the data and assessed the individual risk of bias of the eligible studies using the Cochrane Collaboration Risk of Bias Tool (RoB, version 2.0). The initial search resulted in 808 articles, from which only five (total of 190 participants) were included in the qualitative synthesis. The studies were published from 2014 to 2020. Two presented a low risk of bias + in the mean mouth opening of all patients subjected to bimaxillary surgery who received LLLT. However, the other study found a significant difference in maximum mouth opening in the LLLT group at 14, 30, and 60 days after surgery. Based on limited evidence, LLLT was presented as an auxiliary tool for reducing pain and trismus after surgery. However, the reduction of edema is controversial due to the absence of measuring standardization. | Effects of low-level laser therapy on reducing pain, edema, and trismus after orthognathic surgery: a systematic review | 10.1007/s10103-021-03467-y |
2022-04-01 | Abstract The search for neutrinoless double-beta decay ( $$0\nu 2\beta$$ ), a hypothetical nuclear decay, is one of the major challenges of contemporary physic since its discovery would prove the non conservation of the lepton number and would give an answer to the question of neutrino nature (Dirac or Majorana particles). Starting from the scintillating bolometer technique (a scintillating cryogenic absorber embedding a $$0\nu 2\beta$$ candidate coupled with a cryogenic light detector for dual heat-light readout), BINGO will search for this decay using the knowledge acquired so far by bolometric experiments with the addition of new methods and technologies to reduce drastically the background in the region of interest. BINGO will study two isotopes which have already shown their good suitability for this detection method: $${}^{100}$$ Mo and $${}^{130}$$ Te. The proposed solutions will have a high impact on next-generation bolometric tonne-scale experiments, like CUPID, to push further the sensitivity to the half-life of the process. In this contribution, we present the main axes of the project. | BINGO: Bi-Isotope 0
$$\boldsymbol{\nu}$$
2
$$\boldsymbol{\beta}$$
Next Generation Observatory | 10.3103/S0027134922020096 |
2022-04-01 | Effect of various macroalgae substitution for Sargassum thunbergii in diet on growth, body composition, and survival of sea cucumber ( Apostichopus japonicus ) subjected to air and low salinity exposures was determined. Nine hundred juvenile sea cucumber were distributed into 18 tanks (50 sea cucumber per tank). Six experimental diets were prepared. Sargassum thunbergii was included in the control (Con) diet. The macroalgae Sargassum horneri , Undaria pinnatifida , Saccharina japonica , Ulva australis , and combined U. pinnatifida and S. japonica were included to replace S. thunbergii in the Con diet, referred to as the SH, UA, UP, SJ, and combined diets, respectively. All diets were assigned to triplicate groups of sea cucumber. Sea cucumbers were fed daily for 8 weeks. After the 8-week feeding trial, sea cucumbers were subjected to 30-h air and 12-h low salinity at 10 psu exposures. Weight gain and specific growth rate of sea cucumber fed the Con, SH, and UA diets were significantly greater than those of sea cucumber fed the UP, SJ, and combined diets. The chemical composition of the whole sea cucumber, except for moisture content, was not affected by the experimental diets. No difference in survival of sea cucumber fed all experimental diets was observed at the end of 4-day post observation period after the 30-h air and 12-h low salinity exposures. In conclusion, S. thunbergii can be substituted with either S. horneri or U. australis in sea cucumber feed without retarding growth and stress resistance against air and low salinity exposures. | Macroalgal substitution effect in diet on growth, body composition, and stress resistance of juvenile sea cucumber (Apostichopus japonicus) subjected to air and low salinity exposures | 10.1007/s10811-022-02689-z |
2022-04-01 | Abstract The data of laboratory studies on the effect of low-intensity ultrasound on the toxigenic cyanobacteria Synechocystis sp., the species dominant in the North-West of Russia, cause “blooming” of drinking water sources and pose a danger to the health of the population of cities and rural areas. The study revealed that ultrasonic irradiation is stressful for cyanobacteria. It has been found for the first time that, under stress, they simultaneously trigger two metabolic mechanisms: 1) increasing the thickness of cell walls and mucous membranes (cases) to increase stress resistance; 2) biosynthesis of toxins to combat external influences. Both mechanisms are energy-consuming, and after two to three weeks, a period of depletion of reserves and cell death begins. The results of laboratory and experimental studies on water bodies open up a real possibility of regulating the toxigenic cyanobacterial “blooming” of freshwater water bodies using low-intensity ultrasonic irradiation. | The Problem of Regulation of Toxigenic Blooming in Freshwater Bodies | 10.1134/S0097807822020129 |
2022-04-01 | The aim of the study was to explore the effect and mechanism of a low-level laser on hair follicle stem cells in full-thickness skin wound healing in mice. Full-thickness skin defects were generated by a 5-mm punch biopsy tool on the backs of depilated C57/BL6N mice, which were randomly divided thereafter into a low-dose laser treatment group (LLLT-Low), a high-dose laser treatment group (LLLT-High), and a control group (control). From the day of modeling to the day before the skin samples were taken, the wound area and wound edge of the mice in the LLLT-Low and LLLT-High groups were irradiated with a laser comb every 24 h, and the energy density was 1 J/cm 2 and 10 J/cm 2 , respectively. The control group was irradiated with an ordinary fluorescent lamp. At 0, 3, 5, 10, and 14 days after modeling, pictures of each wound were taken, and the percent wound closure was analyzed. At 3, 5, 10, and 14 days after modeling, the samples were observed by hematoxylin and eosin (HE) and immunofluorescence (IF) staining. Whole transcriptome sequencing (RNA-Seq) was performed on the samples on day 10. Gene Ontology (GO) analysis was performed, and the results were validated by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). The analysis of the percent of wound closure showed that healing was accelerated (significantly from 5 to 10 days) in the LLLT-Low group, but there was no clear change in the LLLT-High group. HE staining showed that the LLLT-Low group had an increasing number of hair follicles and a tendency to migrate to the center of the wound. There was no significant increase in the number of hair follicles and no obvious migration in the LLLT-High group. Immunofluorescence staining showed that the total number of CK15 + hair follicle stem cells in the LLLT-Low group was higher than that in the control group and LLLT-High group at all time points. The number and farthest migration distance of CK15 + hair follicle stem cells increased significantly with time, and after 5 days, they were significantly higher than those in the control group and LLLT-High group. RNA-Seq and Western blot analysis showed that the expression of related genes in hair follicle stem cells, including CK15, in the LLLT-Low group was upregulated. GO analysis and ELISA showed that the expression of many cytokines, represented by IL34, in the LLLT-Low group was upregulated. Low-level laser treatment can promote the proliferation, differentiation, and migration of CK15 + hair follicle stem cells by upregulating the cytokine IL34, thereby promoting skin wound healing in mice. | Low-level laser treatment promotes skin wound healing by activating hair follicle stem cells in female mice | 10.1007/s10103-021-03419-6 |
2022-04-01 | The aim of this study was to evaluate the impact of photobiomodulation therapy (PBMT) on histomorphological aspects of submandibular gland (SMG) submitted to salivary gland duct obstruction in hypothyroid rats. Fifty-six male Wistar rats (250 to 300 g) were divided into 4 groups ( n = 14): euthyroid (EU), EU + PBMT, hypothyroid (HYPO), and HYPO + PBMT. Duct obstruction of the left submandibular gland (LSMG) was performed in all animals by a ligature procedure. For the induction of hypothyroidism, total thyroidectomy was performed. PBMT groups received irradiation with AlGaInP diode laser (808 nm, 0.04 W, 0.04cm 2 spot size, 60 s, 2.4 J per point, 60 J/cm 2 , 1 W/cm 2 ). Irradiation was performed immediately, 24 h, and 48 h after the obstruction of the salivary gland duct, in one point, extra oral and perpendicular to the gland. Animals were sacrificed after 24 h and 72 h after duct ligature. Our results indicated that salivary duct obstruction and hypothyroidism caused negative modifications on the salivary glands’ histomorphology, especially acinar atrophy, after 24 h and 72 h. HYPO + PBMT showed a significant reduction of the inflammatory infiltrate, congested blood vessels, and acinar atrophy in the SMG submandibular salivary gland in 72 h compared to 24 h ( p < 0.05). In conclusion, obstruction of the salivary gland excretory duct and hypothyroidism causes severe sialoadenitis with expressive atrophy of the glandular parenchyma. However, PBMT was able to modulate the inflammatory process and delaying acinar atrophy. This study provided insights to better understand the role of the PBMT on the altered salivary gland by duct ligation and associate hypothyroidism. | Impact of photobiomodulation therapy on the morphological aspects of submandibular gland submitted to excretory duct ligation and hypothyroidism: an animal study | 10.1007/s10103-021-03463-2 |
2022-04-01 | Here we present zircon U–Pb–Hf and whole-rock major and trace element studies of eastern Ningzhen W-Mo-ore-related magmatic rocks, Yushan and Longwangshan granitic rocks, to constrain their form timing, magma sources, and tectonic settings. The results showed that the two plutons were formed in the Early Cretaceous with 206 Pb/ 238 U ages of 107.8 ± 1.2 and 105.2 ± 1.5 Ma ( 206 Pb/ 238 U), respectively. The trapped/residual zircons are mainly distributed in 2.0–2.5 Ga. The two intrusions are characterized by high silicon (68.60–73.99%), high aluminum (13.56–15.02%), high Mg# (47–55), high Sr, Sr/Y, La N /Y N, and low Yb, falling into high Mg# adakitic rock region. The zircon εHf (t) values of the two intrusions range from −24.8 to −13.2, indicating an ancient continental crust in their magma sources. The average Ti-in-zircon temperature is 689 °C, slightly higher than those of other high-Mg adakitic rocks in the lower Yangtze River belt, but lower than those of high-Mg adakitic rocks in the Southern Tanlu Fault (STLF). Zircon Ce 4+ /Ce 3+ show low oxygen fugacity (LWS-1: 3–400, average 92; sample ZYS-4: 9–382, average 93). These geochemical features indicate a thickened lower continental crust in the Eastern Ningzhen region in a subduction setting. Comparing the geochemical characteristics of the eastern Ningzhen to the western Ningzhen and other areas in the Lower Yangtze River Metallogenic Belt (LYRMB) and the high-Mg ore-barren adakitic rocks of the STLF, we propose that the magmatic rocks from eastern Ningzhen may be mainly from a thickened lower continental crust that hybridized with a very small part of mantle sources, while the west Ningzhen magmatic rocks may have experienced a higher degree of mantle contaminations in their source. The metallogenic differences between the eastern (W–Mo) and western (Cu–Fe–Pb–Zn) parts of Ningzhen also indicate different proportions of crustal materials in their magma source. | Geochronology and geochemistry of the W-Mo-ore-related granitic rocks from eastern Ningzhen, lower Yangtze river belt, eastern China | 10.1007/s11631-021-00501-2 |
2022-04-01 | This paper presents an experimental study on dynamic response of a forced low-swirl methane/air premixed flame with external acoustic excitation over a wide range of driving frequency. Global flame response in terms of gain and phase delay between flame intensity and incoming velocity perturbation is determined. Local flame response is investigated in detail at three typical frequencies: 55 Hz, 105 Hz and 155 Hz. The effect of swirl number on the flame response is also discussed. Proper orthogonal decomposition is applied to identify the large coherent structures in the forced flame. Experimental results show flame response gain exhibits a successive of valleys and peaks which is dependent on swirl number. Time delay decreases as swirl number is increased. The low-swirl flame oscillates back and forth mainly in the axial direction at low excitation frequency and it turns into radially dominated direction at high frequency. Flame intensity fluctuation is mainly dominated by the tail of the flame at 55 Hz and 155 Hz while the flame response is controlled by a combined effect of the base and tail region at 105 Hz. Further POD analysis shows symmetric, anti-symmetric and helical modes in the flame. The most energetic modes (mode 1 and mode 2) feature a symmetric wave-like structure at low excitation frequency while it tends to be in antisymmetric modes at high frequency. | Dynamic Response of a Forced Low-Swirl Premixed Flame with Acoustic Excitation | 10.1007/s10494-021-00309-3 |
2022-04-01 | Dental pulp cells are a source of multipotent mesenchymal stem cells with a high proliferation rate and multilineage differentiation potential. This study investigated the photobiomodulated bioenergetic effects of mitochondria in osteoblasts that differentiated from human pulp stem cells. The systematic review followed PRISMA guidelines. The PICO question was formulated. Criteria for inclusion and exclusion were established prior to searches being performed on the PubMed/MEDLINE, Embase, and Scopus. Articles were identified and included if published in English within last 10 years; photobiomodulation or low-level laser therapy were discussed; the delivery parameters for dose and time were included and the studies focused on bioenergetics of osteoblast mitochondria. Studies excluded were non-human dental pulp tissue and in vivo studies. A total number of 110 articles were collated, 106 were excluded leaving a total of 4 articles. These studies demonstrated that in vitro use of photobiomodulation was performed using different laser and LED types; InGaAlP; InGaN; and InGaAsP with average wavelengths of 630 to 940 nm. Primary human osteoblastic STRO-1 and mesenchymal stem cell lineages were studied. Three out of four articles confirmed positive bioenergetic effects of photobiomodulation on mitochondria of osteoblasts derived from human pulp cells. This systematic review demonstrated a lack of adequate reporting of bioenergetics of osteoblast mitochondria after photobiomodulation treatment. | Bioenergetics of photobiomodulated osteoblast mitochondrial cells derived from human pulp stem cells: systematic review | 10.1007/s10103-021-03439-2 |
2022-04-01 | Introduction and aim Urodynamics (UDS) is the current gold standard investigation for explaining pathology in lower urinary tract dysfunction. The role of UDS is to answer a urodynamic question based on reproducing the patient’s symptoms. Despite the introduction of several standardization documents on terminology and methodology for performing UDS and the standard of equipment required, there remains no standardization on how to report and therefore how to interpret UDS findings. The lack of guidance in this specific area may undermine the value of this extremely important tool in the patient evaluation. The aim of this article is to propose a standardized proforma and checklist for the reporting of UDS studies; the main text discusses the rationale for the proforma. Methods This document underwent four rounds of review by the working group and external review by Andrew Gammie. Between each round the document was re-circulated for comment and the comments collated and then reviewed for adoption or rejection based on consensus prior to the document going for further external review. The comments of the external review were then collated and again circulated for consideration prior to adoption based on consensus and the paper put out to review by an IUGA committee public consultation prior to being submitted for publication. Results This article sets out the rationale for a standardized proforma for reporting female UDS. Conclusion This document gives a standardized approach to reporting of UDS. The importance of this is based on UDS being part of a process and not an isolated event. Standardized reporting, like the WHO checklist, gives a framework to ensure that the test has been ordered appropriately and that the final report refers to the indication rather than merely the observations. As such, a standardized report has a better chance of being interpreted appropriately for the woman’s symptoms. | IUGA report on reporting urodynamics in women | 10.1007/s00192-021-04742-w |
2022-04-01 | We are currently facing a pandemic that continuously causes high death rates and has negative economic and psychosocial impacts. Therefore, this period requires a quick search for viable procedures that can allow us to use safe and non-invasive clinical tools as prophylactic or even adjuvant methods in the treatment of COVID-19. Some evidence shows that photobiomodulation therapy (PBMT) can attenuate the inflammatory response and reduce respiratory disorders similar to acute lung injury (ALI), complications associated with infections, such as the one caused by the new Coronavirus (SARS-CoV-2). Hence, the aim of the present study was to evaluate the influence of PBMT (infrared low-level laser therapy) on the treatment of ALI, one of the main critical complications of COVID-19 infection, in an experimental model in rats. Twenty-four male Wistar rats were randomly allocated to three experimental groups ( n = 8): control group (CG), controlled ALI (ALI), and acute lung injury and PBM (ALIP). For treatment, a laser equipment was used (808 nm; 30 mw; 1.68 J) applied at three sites (anterior region of the trachea and in the ventral regions of the thorax, bilaterally) in the period of 1 and 24 h after induction of ALI. For treatment evaluation, descriptive histopathological analysis, lung injury score, analysis of the number of inflammatory cells, and expression of interleukin 1 β (IL-1β) were performed. In the results, it was possible to observe that the treatment with PBMT reduced inflammatory infiltrates, thickening of the alveolar septum, and lung injury score when compared to the ALI group. In addition, PBMT showed lower immunoexpression of IL-1β. Therefore, based on the results observed in the present study, it can be concluded that treatment with PBMT (infrared low-level laser therapy) was able to induce an adequate tissue response capable of modulating the signs of inflammatory process in ALI, one of the main complications of COVID-19. | Influence of photobiomodulation therapy on the treatment of pulmonary inflammatory conditions and its impact on COVID-19 | 10.1007/s10103-021-03452-5 |
2022-04-01 | The present study aimed at investigating the antidepressant and antioxidant actions of near-infrared (NIR) laser at a wavelength of 830 nm and power of 100 mW which applied transcranially on an animal model of depression induced by repeated doses of reserpine (0.2 mg/kg). Thirty male Wistar adult rats were divided into three groups: rat model of depression; rat model of depression irradiated with laser for 14 days after induction of depression; and the control group that was given the drug vehicle and sham-exposed to the laser. Forced swimming test (FST) was used to verify the induction of animal model of depression and to screen the effect of antidepressant effect of low-level laser at the end of the experiment. Monoamine level, oxidative stress markers, and activities of acetylcholinesterase (AchE) and monoamine oxidase (MAO) were determined in the cortex and hippocampus of the rat brain. Reserpine resulted in depletion of monoamines and elevation in the oxidative stress markers and change in the enzymatic activities measured in both brain areas. Laser irradiation has an inhibitory action on the monoamine oxidase (MAO) in the cortex and hippocampus leading to elevation of the monoamine levels and attenuation of the oxidative stress in the studied areas. FST has emphasized the antidepressant effect of the utilized laser irradiation parameters on the behavioral level. The present findings provide evidence for the antidepressant and antioxidant actions of NIR low-power laser in the rat model of depression. Accordingly, low-laser irradiation may be presented as a potential candidate modality for depression treatment . | Antidepressant and antioxidant effects of transcranial irradiation with 830-nm low-power laser in an animal model of depression | 10.1007/s10103-021-03410-1 |
2022-04-01 | The aim of this study was to assess the changes induced by photobiomodulation therapy in oxygenation of normal skin and underlying tissue using hyperspectral imaging combined with a chemometric regression approach. Eleven healthy adult volunteers were enrolled in this study. The dorsal side of the left hand of each subject was exposed to photobiomodulation therapy, while the correspondent side of the right hand was used as a control (placebo effect). Laser irradiation was performed with a laser diode system (635 nm, 15mW, 9 J/cm 2 ) for 900 s. Changes in skin oxygenation were assessed before and after applying the photobiomodulation therapy and placebo using the hyperspectral imaging. Hyperspectral data analysis showed that variations of oxyhemoglobin and deoxyhemoglobin concentrations had no statistical significance in both groups. In conclusion, photobiomodulation therapy does not induce changes in oxyhemoglobin and deoxyhemoglobin concentrations in the normal skin measured from hyperspectral images, at least at λ = 635 nm and 900-s exposure time. | New evidence from hyperspectral imaging analysis on the effect of photobiomodulation therapy on normal skin oxygenation | 10.1007/s10103-021-03397-9 |
2022-04-01 | The objectives of this study are to develop prediction models for total laser energy ( TLE ) in order to infer surgical time and assist operative planning of intrarenal low-power Ho:YAG laser lithotripsy, and to predict the fragmented volume as well as the stone-free status ( SFS ). A retrospective review was performed, comprising all single surgeon standardized retrograde intrarenal surgery and low-power Ho:YAG laser lithotripsy at a tertiary care centre between October 2014 and September 2019. Automated measurement of stone volume and stone density ( MSD ), measured in Hounsfield units (HU), was employed in both pre- and post-operative non-contrast-enhanced computed tomography (NCCT), using a standardized technique on Osirix Lite® software. SFS was defined as complete absence of stone fragments, or fragments < 0.1 cm on meticulous inspection at the end of the procedure, and residual stone burden < 0.0005 cm 3 on postoperative NCCT at 3 months. Statistical analysis was performed using the STATA® version 13.1 software for regression models. A p value < .05 was considered statistically significant. A total of 100 patients met the inclusion criteria, requiring a median of 22.3 kJ/cm 3 (13.4–36.0) and resulting in a SFS of 41% at 3 months. In a multivariate analysis, according to stone composition, predicted TLE is equal: for uric acid (UA), 11.17 × volume (cm 3 ) + 0.17 × MSD (HU) + 7.48 kJ; for mixed stones, 11.17 × volume (cm 3 ) + 0.17 × MSD (HU) + 6.26 kJ; for calcium oxalate monohydrate (CaOM) stones, 11.17 × volume (cm 3 ) + 0.17 × MSD (HU) + 1.14 kJ; and for calcium phosphate (CaPh) stones 11.17 × volume (cm 3 ) + 0.17 × MSD (HU) − 1.94 kJ. Predicted fragmented volume is equal to 0.93 × volume (cm 3 ) cm 3 . The significant predictors for SFS were UA stones, the presence of multiple stones, and lower TLE . In clinical practice, our models for intrarenal low-power Ho:YAG laser lithotripsy indicate that larger, denser, and UA stones are associated to higher TLE , and that single and UA stones are more commonly associated to SFS . Since higher TLE means longer operative time, when adjusting for laser parameters, our prediction models may help urologists plan surgeries more precisely based on stone characteristics, ultimately optimizing patients’ treatment. | Prediction models of low-power holmium laser effectiveness in renal stone lithotripsy during retrograde intrarenal surgery | 10.1007/s10103-021-03445-4 |
2022-04-01 | After the new molecular-based classification was reported to be useful for predicting prognosis, the T2-fluid-attenuated inversion recovery (FLAIR) mismatch sign has gained interest as one of the promising methods for detecting lower grade gliomas (LGGs) with isocitrate dehydrogenase (IDH) mutations and chromosome 1p/19q non-codeletion (IDH mut-Noncodel) with high specificity. Although all institutions could use T2-FLAIR mismatch sign without any obstacles, this sign was not completely helpful because of its low sensitivity. In this study, we attempted to uncover the mechanism of T2-FLAIR mismatch sign for clarifying the cause of this sign’s low sensitivity. Among 99 patients with LGGs, 22 were T2-FLAIR mismatch sign-positive (22%), and this sign as a marker of IDH mut-Noncodel showed a sensitivity of 55.6% and specificity of 96.8%. Via pathological analyses, we could provide evidence that not only microcystic changes but the enlarged intercellular space was associated with T2-FLAIR mismatch sign ( p = 0.017). As per the molecular analyses, overexpression of mTOR-related genes (m-TOR, RICTOR) were detected as the molecular events correlated with T2-FLAIR mismatch sign ( p = 0.020, 0.030. respectively). Taken together, we suggested that T2-FLAIR mismatch sign could pick up the IDH mut-Noncodel LGGs with enlarged intercellular space or that with overexpression of mTOR-related genes. | T2-fluid-attenuated inversion recovery mismatch sign in lower grade gliomas: correlation with pathological and molecular findings | 10.1007/s10014-022-00433-6 |
2022-03-31 | This study investigated the road performance and microscopic action mechanism of low liquid limit silt solidified by AT curing agent: firstly, carrying out the compaction test of low liquid silt solidified by different contents of AT curing agent; secondly, according to different curing ages, carrying out the CBR test in laboratory; thirdly, simulating the local seasonal frozen environment and carrying out the unconfined compressive strength (UCS) test under the action of freeze–thaw cycles; and lastly, on this basis, using x-ray diffraction (XRD) and scanning electron microscopy (SEM) to further research the micro-mechanism formed by UCS of low liquid limit silt cured by AT curing agent. The results show that the content of AT curing agent has little effect on the optimum moisture content of low liquid limit silt; compaction degree and curing age are very important to increase CBR strength of solidified low liquid limit silt. The UCS of solidified low liquid limit silt increases with the increase of content; especially at 5% content, the UCS of the sample has a particularly obvious improvement; under the condition of 96% compaction degree and 28 days of curing, the CBR strength of samples with 5% AT curing agent is 1.85 times, 1.58 times, 1.25 times, and 1.07 times of samples with 0.5%, 1%, 2%, and 3% AT curing agent. The UCS of low liquid limit silt solidified by AT curing agent with different contents decreases with the increase of freeze–thaw cycles and tends to be steady after 8 freeze–thaw cycles. Microscopic analysis results show that compared with sodium silicate, AT curing agent can produce more cementing substances, which can be cemented with soil particles and make soil more compact, as well as with the increase of curing agent content, the cementing substances also increase; as a result, silica gel, N(C 2 H 4 ONa) 3 ·mSiO 2 ·nH 2 O composite crystal, and aluminum silicate produced by the reaction can effectively improve CBR strength, UCS, and stability of soil samples. Finally, carrying out the field test of solidified low liquid limit silt subgrade, it is found that the solidified low liquid limit silt with 1% AT curing agent can meet the filling requirements of roadbed on expressway and first-class highways. | Road performance and microscopic action mechanism of low liquid limit silt solidified by AT curing agent | 10.1007/s12517-022-09878-7 |
2022-03-31 | Visibility and aerosol optical depth (AOD) characterization, and their relationship with PM 10 and local and synoptic meteorology, were studied for January–March in 2014 and 2015 over Bangkok. Visibility degradation intensifies in the dry season as compared to the wet season due to increase in PM 10 and unfavorable meteorological conditions. The average visibility is lower in January and February as compared to the other months. Relatively higher AOD in March despite lower PM 10 is attributed to the synergetic effect of moderate relative humidity, secondary aerosols, elevated aerosol layer due to summertime convection, and biomass burning. Larger variability in visibility and PM 10 in winter months is due to more synoptic weather fluctuations while AOD shows similar variability for all months attributed partly to fires. Higher PM 10 and moderate-to-high relative humidity cause lower visibility in the morning while it improves in afternoon as PM 10 and relative humidity decrease. AOD is higher in the afternoon as compared to that in the morning and evening as it is less sensitive to diurnal change in aerosols and meteorology at the surface level. Visibility and AOD relationships with PM 10 are dependent on relative humidity. Weaker winds lead to lower visibility, higher PM 10 , and higher AOD irrespective of wind direction . Stronger winds improve visibility and decrease PM 10 for all directions while AOD is higher for all directions except eastern and northeastern. The back-trajectory results show that the transport of pollutant and moist air is coupled with the synoptic weather and influence visibility and AOD. Two low-visibility events were investigated. The first event is potentially caused by the combined effect of local emissions and their accumulation due to stagnant weather conditions, secondary aerosols, and forest fires in the nearby regions. The second event can be attributed to the local emission and fires in the nearby area with hygroscopic growth of aerosols due to moist air from the Gulf of Thailand. Based on these findings, some policy implications have also been given. | Visibility, aerosol optical depth, and low-visibility events in Bangkok during the dry season and associated local weather and synoptic patterns | 10.1007/s10661-022-09880-2 |
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