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2021-04-01 | The metabolically engineered plant pathogen Ustilago maydis MB215 Δ cyp3 P etef ria1 has been cultivated to produce more than 80 g/L itaconate in 16 L scale pH and temperature controlled fermentation, in fed-batch mode with two successive feedings. The effect of pH as well as successive rounds of feeding has been quantified via elemental balances. Volumetric itaconic acid productivity gradually decreased with successive glucose feedings with increasing itaconic titers, with nearly constant product yield. Extracellular pH was decreased from 6 down to 3.5 and the fermentation was characterized in specific uptake, production, and growth rates. Notable is that the biomass composition changes significantly from growth phase to itaconic acid production phase, carbon content increases from 42% to around 62%. Despite the gradual decrease in itaconic acid levels with decreasing pH (nearly 50% decrease in itaconic acid at pH 3.5, compared to pH 6), significant itaconate production is still observed at pH 4 (around 63 g/L). Biomass yield remained nearly constant until pH 4. Taken together, these results strongly illustrate the potential of engineered Ustilago maydis in itaconate production at commercial levels. | High level production of itaconic acid at low pH by Ustilago maydis with fed-batch fermentation | 10.1007/s00449-020-02483-6 |
2021-04-01 | Background An estimated 5–10 % of healthy vaccinees lack adequate antibody response following receipt of a standard three-dose hepatitis B vaccination regimen. The cellular mechanisms responsible for poor immunological responses to hepatitis B vaccine have not been fully elucidated to date. Methods There were 61 low responders and 56 hyper responders involved in our study. Peripheral blood samples were mainly collected at D7, D14 and D28 after revaccinated with a further dose of 20 µg of recombinant hepatitis B vaccine. Results We found low responders to the hepatitis B vaccine presented lower frequencies of circulating follicular helper T (cTfh) cells, plasmablasts and a profound skewing away from cTfh2 and cTfh17 cells both toward cTfh1 cells. Importantly, the skewing of Tfh cell subsets correlated with IL-21 and protective antibody titers. Based on the key role of microRNAs involved in Tfh cell differentiation, we revealed miR-19b-1 and miR-92a-1 correlated with the cTfh cell subsets distribution and antibody production. Conclusions Our findings highlighted a decrease in cTfh cells and specific subset skewing contribute to reduced antibody responses in low responders. | Circulating Tfh cell and subsets distribution are associated with low‐responsiveness to hepatitis B vaccination | 10.1186/s10020-021-00290-7 |
2021-04-01 | With the acceleration of urbanization, the unknown risks faced by cities and regions are also increasing, and their vulnerability is exposed, which has become a major problem hindering sustainable development. Through the study of disaster risk assessment, we can find out regional disaster-causing factors and social vulnerability factors, so as to provide a basis for targeted response to the impact of natural disasters. Based on the HOP model put forward by Susan L. Cutter, this study studied the Place Vulnerability = Hazards Exposure Level × Social Vulnerability Index as the main calculation formula. The natural disaster frequency and socio-economic structure index of 83 sample cities in the middle and lower reaches of Yangtze river in 2016 were calculated by combing historical literature. SPSS software was used to analyze the principal component of the socio-economic data of the sample city. Through the calculation of the total variance contribution rate and dimensionality reduction processing, the selected 14 index factors were extracted and processed into 5 principal component factors. According to the index weight coefficient, the comprehensive score of the city’s social vulnerability was calculated. As a result, with the combination of hazards exposure level score and Social Vulnerability Index score, the Place Vulnerability scores in the middle and lower reaches of Yangtze river were obtained and analyzed with clustering. Finally, the distribution characteristics of regional natural disasters and socio-economic structures were described. | Place vulnerability assessment based on the HOP model in the middle and lower reaches of the Yangtze River | 10.1007/s10708-019-10092-4 |
2021-04-01 | Abstract The batch processing of an organic solvent methyl tert -butyl ether with obtaining a product of high purity was investigated. The separation coefficients of methyl tert -butyl ether and the main impurities contained in the technical product are found. Static and hydrodynamic parameters of the process were determined. The efficiency of the batch processing method for low-tonnage production of high-purity methyl tert -butyl ether was demonstrated. | Production of Highly Pure Methyl tert-Butyl Ether | 10.1134/S1070427221040157 |
2021-04-01 | Purpose This paper aims to show the potentialities of computational bioengineering in the field of lower urinary tract pathophysiology. Engineering methods allow the investigation of urine flow in healthy and pathologic conditions and the analysis of urethral occlusion by means of artificial urinary sphincters. Methods Computational models of bladder and urethra were developed and exploited to investigate the lower urinary tract physiology in health and in disease. Average male morphometric configurations were assumed, together with typical properties of both biological tissues and fluids. The reliability of the models was assessed by the mutual comparison of results and the investigation of data from experimental and clinical activities. Results The developed models allowed to analyze typical situations, such as the micturition in health and in disease, and the lumen occlusion by external devices. The models provided information that clinical and experimental tests barely provide, as the occurrence of turbulent phenomena within urine flow, the shear stresses at the lumen wall, the external pressure that is strictly required to occlude the lumen. Conclusions The methods of bioengineering allow broadening and deepening the knowledge of the lower urinary tract functionality. More in detail, modeling techniques provide information that contributes to explain the occurrence of pathological situations, and allows to design and to optimize clinical-surgical procedures and devices. | Computational Tools for the Investigation of the Male Lower Urinary Tract Functionality in Health and Disease | 10.1007/s40846-021-00599-y |
2021-04-01 | Oral squamous cell carcinoma (OSCC) is the most common head and neck malignancy; it has been shown that cancer stem cells (CSC) are present in OSCC and associated with tumor growth, invasion, metastasis, and therapeutic resistance. Photobiomodulation (PBM) is an alternative tool for oncologic treatment adverse effects such as oral mucositis (OM); however, controversy exists regarding the undesirable effects of PBM on tumor or CSC. This study aimed to evaluate in vitro, the effects of PBM, with the same dosimetric parameters as those used in the clinic for OM prevention and treatment, on OSCC cellular viability, as well as PBM’s effect on CSC properties and its phenotype. OSCC cell lines were submitted to single or daily PBM with 3 J/cm 2 and 6 J/cm 2 and then the cellular viability was evaluated by MTT, NRU (neutral red uptake), and CVS (crystal violet staining). The CSC populations were evaluated by clonogenic formation assay, flow cytometry, and RT-qPCR. The single PBM with the 3 J/cm 2 group was associated with increased cellular viability. Daily PBM with 3 J/cm 2 and 6 J/cm 2 was associated with a significant decrease in cellular viability. Additionally, daily PBM was not able to promote CSC self-renewal or the CD44 high /ESA low and CD44 high /ESA high cellular phenotypes. Moreover, a decrease in the number of spheres and in the expression of the CSC related gene BMI1 was observed after daily PBM with 6 J/cm 2 . Daily PBM with 3 J/cm 2 and 6 J/cm 2 showed an inhibitory effect on cellular viability and was not able to promote the CSC self-renewal or phenotype. | Effects of photobiomodulation on cellular viability and cancer stem cell phenotype in oral squamous cell carcinoma | 10.1007/s10103-020-03131-x |
2021-04-01 | Purpose Carbohydrate (CHO) restriction could be a potent metabolic regulator of endurance exercise-induced muscle adaptations. Here, we determined whether post-exercise CHO restriction following strenuous exercise combining continuous cycling exercise (CCE) and sprint interval exercise could affect the gene expression related to mitochondrial biogenesis and oxidative metabolism in human skeletal muscle. Methods In a randomized cross-over design, 8 recreationally active males performed two cycling exercise sessions separated by 4 weeks. Each session consisted of 60-min CCE and six 30-s all-out sprints, which was followed by ingestion of either a CHO or placebo beverage in the post-exercise recovery period. Muscle glycogen concentration and the mRNA levels of several genes related to mitochondrial biogenesis and oxidative metabolism were determined before, immediately after, and at 3 h after exercise. Results Compared to pre-exercise, strenuous cycling led to a severe muscle glycogen depletion (> 90%) and induced a large increase in PGC1A and PDK4 mRNA levels (~ 20-fold and ~ 10-fold, respectively) during the acute recovery period in both trials. The abundance of the other transcripts was not changed or was only moderately increased during this period. CHO restriction during the 3-h post-exercise period blunted muscle glycogen resynthesis but did not increase the mRNA levels of genes associated with muscle adaptation to endurance exercise, as compared with abundant post-exercise CHO consumption. Conclusion CHO restriction after a glycogen-depleting and metabolically-demanding cycling session is not effective for increasing the acute mRNA levels of genes involved in mitochondrial biogenesis and oxidative metabolism in human skeletal muscle. | Carbohydrate restriction following strenuous glycogen-depleting exercise does not potentiate the acute molecular response associated with mitochondrial biogenesis in human skeletal muscle | 10.1007/s00421-021-04594-8 |
2021-04-01 | Objectives To explore a method to create affordable anatomical models of the biliary tree that are adequate for training laparoscopic cholecystectomy with an in-house built simulator. Methods We used a fused deposition modeling 3D printer to create molds of Acrylonitrile Butadiene Styrene (ABS) from Digital Imaging and Communication on Medicine (DICOM) images, and the molds were filled with silicone rubber. Thirteen surgeons with 4–5-year experience in the procedure evaluated the molds using a low-cost in-house built simulator utilizing a 5-point Likert-type scale. Results Molds produced through this method had a consistent anatomical appearance and overall realism that evaluators agreed or definitely agreed (4.5/5). Evaluators agreed on recommending the mold for resident surgical training. Conclusions 3D-printed molds created through this method can be applied to create affordable high-quality educational anatomical models of the biliary tree for training laparoscopic cholecystectomy. | 3D-printed anatomical models of the cystic duct and its variants, a low-cost solution for an in-house built simulator for laparoscopic surgery training | 10.1007/s00276-020-02631-3 |
2021-04-01 | Background Since Rothenberg first performed thoracoscopic repair for esophageal atresia with distal tracheoesophageal fistula (EA/TEF) successfully in 2000, thoracoscopic repair has achieved status as a routine procedure worldwide. Previously, an international multicenter study reported that this procedure was not inferior to conventional open surgery. However, thoracoscopic surgery is a highly difficult operation for surgeons and anesthesiologists; as a result, the safety and efficacy of the surgery is still under debate. Considering these circumstances, the purpose of this study was to analyze the results of single-center thoracoscopic surgery and to compare the outcomes relative to the patient’s weight at the time of surgery. Methods We retrospectively analyzed patients with EA/TEF who underwent thoracoscopic surgery in a single center between October 2008 and February 2017. Results In total, 41 cases of thoracoscopic repair of EA/TEF were performed. Upon subgrouping by over and under 2000 g of body weight at the time of operation, 34 were found to be over 2000 g and seven were under 2000 g. Intraoperative factors and events were not significantly different between the two groups. Additionally, most of the postoperative outcomes, including the rate of postoperative leakage and strictures, showed no difference. On the other hand, the under 2000 g group had more gastroesophageal reflux requiring fundoplication than did the heavier group ( P = 0.04). Conclusions The results of this center’s thoracoscopic repair of EA/TEF were not inferior to other centers’ outcomes. Additionally, the intraoperative and postoperative outcomes were similar despite differences in weight at operation. Therefore, thoracoscopic repair might be a feasible surgical option for infants weighing less than 2000 g when performed by a surgeon and anesthesiologist team who are experienced in pediatric thoracoscopic surgery. | Thoracoscopic repair of esophageal atresia with distal tracheoesophageal fistula: is it a safe procedure in infants weighing less than 2000 g? | 10.1007/s00464-020-07538-z |
2021-04-01 | Suncun coal mine in Xinwen mining area is a typical deep rockburst mine. And the main mining seams are the No.2 and No.4 coal seams. The No.2 coal seam is with the weak bursting liability, and its roof and floor with the strong bursting liability; the No.4 coal seam and its roof and floor are with the weak bursting liability. In order to ensure the safe production of mine, the No.4 coal seam should be chosen as the liberating seam and firstly mined. Therefore, first of all, the upward mining feasibility of coal seam group is studied by theoretical analysis method, and then the structural evolution, fracture development and stress distribution characteristics of overlying strata in stope after mining of No.4 coal seam are studied by numerical simulation method. The research results show that the mining of No.4 coal seam do not destroy the mining condition of No.2 coal seam, instead, it can effectively reduce or even eliminate the bursting risk in the process of No.2 coal seam mining. Based on the above research results, the No.4 coal seam was mined by the following prevention and control rockburst measures, namely: the large-diameter borehole for pressure relief of coal mass, and the drilling cutting method for effect test and evaluation. Besides, the borehole stress sensors are used to monitor and analyze the pressure relief effect of No.2 coal seam after mining of No.4 coal seam. The in-situ monitoring results show that the implementation of large-diameter pressure relief borehole in the front of working face can effectively ensure the safe production in coal seam with weak bursting liability; and the mining of liberating seam is an effective measure for safe production in coal seam with strong bursting liability. | Overlying Strata Structure Evolution and Engineering Practice Based on the Mining of Lower Liberating Seam in Deep Bursting Coal Seam Group | 10.1007/s10706-021-01693-3 |
2021-04-01 | This study evaluated the effect of photobiomodulation therapy (PBMt) before or after a high-intensity resistance exercise (RE) session on muscle oxidative stress. Female Wistar rats were assigned to one of the following groups: Sham (non-exercised, undergoing placebo-PBMt); NLRE (exercised, undergoing placebo-PBMt); PBMt + RE (pre-exercise PBMt); RE + PBMt (post-exercise PBMt). The RE comprised four climbs bearing the maximum load with a 2 min rest between each climb. An 830-nm aluminum gallium arsenide diode laser (100 mW; 0.028 cm 2 ; 3.57 mW/cm 2 ; 142.8 J/cm 2 ; 4 J; Photon Laser III, DMC, São Paulo, Brazil) was applied 60 s before or after RE in gastrocnemius muscles. Analyses were performed at 24 h after RE: lipoperoxidation using malondialdehyde (MDA) and protein oxidation (OP) on Western blot. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity were spectrophotometrically assessed. Nitric oxide (NO) level was determined by the Griess reaction. The MDA and OP levels were significantly higher in the NLRE group. Increased OP was prevented in all PBMt groups; however, increased MDA was prevented only in the RE + PBMT group. The RE + PBMt group had higher SOD activity compared to all other groups. A higher GPx activity was observed only in the PBMT + RE compared to Sham group, and CAT activity was reduced by RE, without PBMt effect. NO levels were unchanged with RE or PBMt. Therefore, PBMt application after a RE section has a more potent antioxidant effect than previous PBMt. Rats submitted to post-RE PBMt illustrated prevention of increased lipoperoxidation and protein oxidation as well as increased SOD activity. Graphic abstract The photobiomodulation can attenuate oxidative stress induced by resistance exercise. A more evident benefit shows to be obtained with the application after exercise, in which it has increased the activity of superoxide dismustase. | Post-resistance exercise photobiomodulation therapy has a more effective antioxidant effect than pre-application on muscle oxidative stress | 10.1007/s43630-021-00042-w |
2021-04-01 | Purpose Lumbar Modic change (MC) can serve as a diagnostic marker as well as an independent source of chronic low back pain (CLBP). This study aimed to test for the existence of serum biomarkers in CLBP patients with MC. Methods Age- and sex-matched CLBP patients with confirmed MC on lumbar MRI (n = 40) and pain-free controls (n = 40) were assessed. MC was classified into M1, predominating M1, predominating M2 and M2. MC volumes were calculated. Fasting blood samples were assessed for inflammatory mediators, signalling molecules, growth factors and bone turnover markers. Serum concentrations of 46 biomarkers were measured. Results Median concentrations of interleukin (IL)-15 ( p < 0.001), IL-8 ( p < 0.001), tumour necrosis factor (TNF)-alpha ( p < 0.001), Eotaxin-1 ( p < 0.05), Eotaxin-3 ( p < 0.001), monocyte chemotactic protein (MCP)-1 ( p < 0.05), macrophage inflammatory protein (MIP)-1alpha ( p < 0.01), TEK receptor tyrosine kinase (Tie)-2 ( p < 0.001), vascular cell adhesion molecule (VCAM)-1 ( p < 0.001), RANTES ( p < 0.001), C telopeptide of type I collagen (CTX)-1 ( p < 0.001), vascular endothelial growth factor (VEGF)-C ( p < 0.001), VEGF-D ( p < 0.05), fms-related tyrosine kinase (Flt)-1 ( p < 0.01) and intercellular adhesion molecule (ICAM)-1 (p < 0.01) were significantly higher among controls. IL-1sRII (23.2 vs. 15.5 ng/ml, p < 0.001) and hepatocyte growth factor (HGF)-1 (169 vs. 105 pg/ml, p < 0.01) concentrations were significantly higher among patients. Type or volume of MC was not associated with biomarker concentrations. Conclusions This is the first study to assess the blood serum biomarker profile in individuals with CLBP with MC. Several biomarkers were suppressed, while two markers (IL-1sRII and HGF) were elevated among MC patients, irrespective of MC type or size, with CLBP compared with asymptomatic controls. | Serum biomarkers for Modic changes in patients with chronic low back pain | 10.1007/s00586-020-06713-z |
2021-04-01 | Scar following caesarean section surgery is an important aspect affecting aesthetics and function in young ladies. This study was done to compare the effectiveness of scar modulation using topical silicone gel in post-lower segment caesarean section scar in primigravida. Case series analysis was conducted between 01 Jul 2018 and 30 Jun 2019 in a tertiary care centre. Post-lower segment caesarean section scars in 52 primigravida were randomised into 2 groups. Group A used topical silicone gel once daily for 3 min of massage. Group B had normal natural scar maturation without any intervention. Observational data collected and photographs were taken at 2 weeks, 4 weeks and 12 weeks. Vancouver scar score used to assess observed data and result compiled. Topical silicone gel gave superior results in reducing overall scar quality at 1 month and 3 months. Topical silicone gel was a superior product for initial management of caesarean scars. | Randomised Control Clinical Trial of Topical Silicone Gel in Post-Lower Segment Caesarean Section Closure scar in Primigravida | 10.1007/s12262-020-02420-7 |
2021-04-01 | The desorbed gas composition and δ 13 C (CH4) and δ D (CH4) of five coal groups in Well DE-A of the Labudalin Basin in northeastern Inner Mongolia show that the δ 13 C (CH4) and δ D (CH4) are heavy, and significantly heavier in some layers, whereas the overall δ 13 C (CO2) is abnormally light. Based on coalfield exploration data, this study analyzes the characteristics and control factors of methane isotope alienation of shallow-buried low-rank multiple coal seams in a small coal-bearing depression. The maximum buried depth of the coal seam in the Derbu coalfield is less than 600 m, and the coal rank is sub-bituminous coal. The carbon isotope composition ( δ 13 C (CH4) ) of CBM varies from − 56.3 to − 39.8‰, wherein the arithmetic average is − 48.72‰. Compared with coal seams of the same metamorphic degree, the δ 13 C (CH4) in Derbu is relatively heavy, wherein different coal groups and different coal seams of the same coal group have different characteristics, and the δ 13 C (CO2) is relatively light. Studies have shown that the existence of thermogenic gas, anaerobic oxidation of methane microorganisms, and desorption-fractionation of methane isotopes in Well DE-A are causes for the heavier δ 13 C (CH4) and δ D (CH4) . Note that the thermal cause is the basis for the heavier δ 13 C (CH4) of the gas sample, while the carbon isotope fractionation of methane and oxidation of microorganisms further aggravate the δ 13 C (CH4) . The preservation conditions, such as lithofacies combination sequence and hydrogeological conditions, of different coal formations are also important factors influencing δ 13 C (CH4) differentiation, and the superposition and coupling of various reasons make this differentiation more obvious. By comparing the geological characteristics of Well DE-A with the vertical variation characteristics of carbon isotopes in the desorbed methane of the Surat Basin, it was concluded that the vertical variation of the desorbed gas sample in shallow-buried low-rank multiple coal seams has complex characteristics. In addition to maturity, local horizons are more obviously controlled by lithologic association and hydrological characteristics. Especially for small coal-bearing depressions or coal-bearing strata near outcrops with shallow-buried depth, the horizontal distance between the outcrop line of different coal formations and target well locations is obviously short. Thus, surface water and surface microorganisms can migrate along the short high permeability layers (coal seam or sandstone layer), and influence the coal-bearing seam. Meanwhile, different groundwater dynamic conditions also result in the transformation of desorbed gas in different coal groups, revealing variation in the methane carbon isotopes. | Differentiation of Carbon Isotope Composition and Stratabound Mechanism of Gas Desorption in Shallow-Buried Low-Rank Multiple Coal Seams: Case Study of Well DE-A, Northeast Inner Mongolia | 10.1007/s11053-020-09781-6 |
2021-04-01 | To investigate the beneficial effects of oridonin, a diterpenoid compound isolated from Rabdosia rubescens, on the inflammatory response in TNBS-induced post-inflammatory irritable bowel syndrome (PI-IBS) model and the underlying mechanism. Using the PI-IBS rat model and Caco-2 cell lines, we found that intestinal barrier function reflected by lactulose/mannitol (L/M) ratio and tight junction protein level was significantly ameliorated by oridonin. We also demonstrated that oridonin abrogated inflammation through inhibiting the phosphorylation of NF-κBp65 as well as its downstream gene (iNOS, COX-2, IL-1β, and IL-6) level. Molecular docking studies confirmed the good binding activity between oridonin and PXR. In Caco-2 cell lines, oridonin markedly inhibited LPS-induced NF-κB activation in a PXR-dependent manner. Meanwhile, PXR and its target genes CYP3A4 and P-gp were induced by oridonin, which was associated with the decreased expression of NF-κB and the recovery of intestinal barrier. This study indicated that the therapeutic effect of oridonin on experimental PI-IBS through repairing intestinal barrier function may be closely associated with the regulatory role of PXR/NF-κB signaling pathway. Oridonin may serve as a PXR ligand for the development of drugs in the therapy for PI-IBS. | Oridonin Attenuates TNBS-induced Post-inflammatory Irritable Bowel Syndrome via PXR/NF-κB Signaling | 10.1007/s10753-020-01364-0 |
2021-04-01 | Objective To assess the short term outcome and predictors of mortality among very low birth weight (VLBW) neonates. Methods This descriptive study from a tertiary care teaching institute in south India included 239 VLBW neonates who were uniformly managed as per unit’s protocol and followed up till discharge or death, whichever was earlier. Univariate analysis and logistic regression analysis were done to determine the predictors of mortality. Two logistic regression models were developed and to evaluate their discriminative performance, area under the receiver operating characteristic curves were calculated. Results Mean gestational age and mean birth weight of neonates were 31.4 ± 3 wk and 1191 ± 245 g respectively. Among the 239 infants, 49 (20.5%) expired and 190 (70.5%) survived. Mortality among extremely low birth weight (ELBW) and extreme preterm infants were 69.3% and 73.3% respectively. Univariate analysis showed multiple perinatal factors and neonatal morbidities were associated with mortality. On adjusted multivariate logistic regression, birth weight < 1000 g (OR 9.27), severe grade of intraventricular hemorrhage (IVH) (OR 29.2), hyperglycemia (OR 7.8) and respiratory distress syndrome (RDS) requiring surfactant therapy (OR 6.2) were the significant predictors of mortality. Both logistic regression models developed showed good prediction of mortality. Conclusions VLBW mortality rate is 20% in the population studied. Birth weight < 1000 g, severe grade of IVH, hyperglycemia, and RDS requiring surfactant therapy were the significant predictors of mortality among VLBW neonates. Both prediction models developed showed good prediction of mortality. | Short Term Outcome and Predictors of Mortality Among Very Low Birth Weight Infants – A Descriptive Study | 10.1007/s12098-020-03456-z |
2021-04-01 | Abstract — The elimination kinetics of carbonyl-modified low density lipoproteins (LDL) from rabbit bloodstream was studied using isolated LDL of rabbits and humans after preliminary biotinylation or labeling with FITC. Rabbit or human blood plasma LDL were isolated using differential ultracentrifugation in a density gradient; after labeling by biotinylation or by FITC, LDL were modified with various low molecular weight natural dicarbonyls: malondialdehyde (MDA), glyoxal or methylglyoxal. Native (control) and dicarbonyl-modified biotinylated or FITC-labeled LDL were injected into the ear vein of rabbits, and blood samples were taken at certain time intervals. The content of biotinylated LDL in blood plasma was determined by an enzyme immunoassay method; FITC-labeled LDL was determined from the fluorescence spectra. It has been found that glyoxal- and methylglyoxal-modified rabbit and human LDL circulate in the bloodstream of rabbits for almost the same period as native (unmodified) LDL. In contrast to this, MDA-modified rabbit and human LDL were very quickly eliminated from the rabbit bloodstream. Dicarbonyl-modified LDL from human blood plasma is not associated with red blood cells or endothelial cells. We found that using the Oxidized LDL ELISA kits (Mercodia, Sweden) it was possible to identify mainly MDA-modified LDL. The level of MDA-modified LDL in the blood plasma of CHD patients sharply decreased during therapy with evolocumab, the hypocholesterolemic inhibitor of PCSK 9 (proprotein convertase of subtilisin/kexin type 9), which activates LDL reutilization in the liver cells. These results explain the extremely rapid clearance of MDA-modified LDL in our experiments by their increased utilization in hepatocytes. The results obtained indicate a high atherogenicity of glyoxal- and methylglyoxal-modified LDL, long-term circulating in the bloodstream. | Clearance of Carbonyl-Modified Low-Density Lipoproteins in Rabbits | 10.1134/S1990750821020104 |
2021-04-01 | Abstract The experiments at the FT-2 tokamak are described that were focused on clearing up the role of the parametric decay instabilities in decreasing the generation efficiency of the non-inductive current excited by the electromagnetic waves in the lower hybrid frequency range. The most discussed instability of such kind is the decay of the pump wave into the daughter high-frequency waves and the low-frequency ion–acoustic quasi-modes. The studies performed have shown that, under conditions of the FT-2 experiment, the ion–acoustic instability has no decisive effect on the decrease in the efficiency of the lower hybrid current drive. | Studies of Spectral Broadening of the Lower Hybrid Wave Line in the Current-Drive Regimes and Ion Heating at the FT-2 Tokamak | 10.1134/S1063780X2104005X |
2021-03-31 | Daily River Malaba flows recorded from 1999 to 2016 were modelled using seven lumped conceptual rainfall–runoff models including AWBM, SACRAMENTO, TANK, IHACRES, SIMHYD, SMAR and HMSV. Optimal parameters of each model were obtained using an automatic calibration strategy. Mismatches between observed and modelled flows were assessed using a total of nine “goodness-of-fit” metrics. Capacity of the models to reproduce historical hydrological extremes was assessed through comparison of amplitude–duration–frequency (ADF) relationships or curves constructed based on observed and modelled flow quantiles. Generally, most of the hydrological models performed better for high than low flows. ADF curves of both high and low flows for various return periods from 5 to 100 years were well reproduced by AWBM, SAC, TANK and HMSV. ADF curves for high and low flows were poorly reproduced by SIMHYD and SMAR, respectively. Overall, AWBM performed slightly better than other models if both high and low flows are to be considered simultaneously. The deviations of these models were larger for high than low return periods. It was found that the choice of a “goodness-of-fit” metric affects how model performance can be judged. Results from this study also show that when focusing on hydrological extremes, uncertainty due to the choice of a particular model should be taken into consideration. Insights from this study provide relevant information for planning of risk-based water resources applications. | Performance of rainfall–runoff models in reproducing hydrological extremes: a case of the River Malaba sub-catchment | 10.1007/s42452-021-04514-7 |
2021-03-31 | Data on comprehensive population-based surveillance of antimicrobial resistance is lacking. In low- and middle-income countries, the challenges are high due to weak laboratory capacity, poor health systems governance, lack of health information systems, and limited resources. Developing countries struggle with political and social dilemma, and bear a high health and economic burden of communicable diseases. Available data are fragmented and lack representativeness which limits their use to advice health policy makers and orientate the efficient allocation of funding and financial resources on programs to mitigate resistance. Low-quality data means soaring rates of antimicrobial resistance and the inability to track and map the spread of resistance, detect early outbreaks, and set national health policy to tackle resistance. Here, we review the barriers and limitations of conducting effective antimicrobial resistance surveillance, and we highlight multiple incremental approaches that may offer opportunities to strengthen population-based surveillance if tailored to the context of each country. | Surveillance of antimicrobial resistance in low- and middle-income countries: a scattered picture | 10.1186/s13756-021-00931-w |
2021-03-30 | Highlights Hard-carbon anode dominated with ultra-micropores (< 0.5 nm) was synthesized for sodium-ion batteries via a molten diffusion–carbonization method. The ultra-micropores dominated carbon anode displays an enhanced capacity, which originates from the extra sodium-ion storage sites of the designed ultra-micropores. The thick electrode (~ 19 mg cm −2 ) with a high areal capacity of 6.14 mAh cm −2 displays an ultrahigh cycling stability and an outstanding low-temperature performance. Abstract Pore structure of hard carbon has a fundamental influence on the electrochemical properties in sodium-ion batteries (SIBs). Ultra-micropores (< 0.5 nm) of hard carbon can function as ionic sieves to reduce the diffusion of slovated Na + but allow the entrance of naked Na + into the pores, which can reduce the interficial contact between the electrolyte and the inner pores without sacrificing the fast diffusion kinetics. Herein, a molten diffusion–carbonization method is proposed to transform the micropores (> 1 nm) inside carbon into ultra-micropores (< 0.5 nm). Consequently, the designed carbon anode displays an enhanced capacity of 346 mAh g −1 at 30 mA g −1 with a high ICE value of ~ 80.6% and most of the capacity (~ 90%) is below 1 V. Moreover, the high-loading electrode (~ 19 mg cm −2 ) exhibits a good temperature endurance with a high areal capacity of 6.14 mAh cm −2 at 25 °C and 5.32 mAh cm −2 at − 20 °C. Based on the in situ X-ray diffraction and ex situ solid-state nuclear magnetic resonance results, the designed ultra-micropores provide the extra Na + storage sites, which mainly contributes to the enhanced capacity. This proposed strategy shows a good potential for the development of high-performance SIBs. | From Micropores to Ultra-micropores inside Hard Carbon: Toward Enhanced Capacity in Room-/Low-Temperature Sodium-Ion Storage | 10.1007/s40820-020-00587-y |
2021-03-30 | Background Pneumoperitoneum and Trendelenburg position in laparoscopic surgeries could contribute to postoperative pulmonary dysfunction. In recent years, intraoperative lung-protective mechanical ventilation (LPV) has been reportedly able to attenuate ventilator-induced lung injuries (VILI). Our objectives were to test the hypothesis that LPV could improve intraoperative oxygenation function, pulmonary mechanics and early postoperative atelectasis in laparoscopic surgeries. Methods In this randomized controlled clinical trial, 62 patients indicated for elective abdominal laparoscopic surgeries with an expected duration of greater than 2 h were randomly assigned to receive either lung-protective ventilation (LPV) with a tidal volume (Vt) of 7 ml kg − 1 ideal body weight (IBW), 10 cmH 2 O positive end-expiratory pressure (PEEP) combined with regular recruitment maneuvers (RMs) or conventional ventilation (CV) with a Vt of 10 ml kg − 1 IBW, 0 cmH 2 O in PEEP and no RMs. The primary endpoints were the changes in the ratio of PaO 2 to FiO 2 (P/F). The secondary endpoints were the differences between the two groups in PaO 2 , alveolar-arterial oxygen gradient (A-aO 2 ), intraoperative pulmonary mechanics and the incidence of atelectasis detected on chest x-ray on the first postoperative day. Results In comparison to CV group, the intraoperative P/F and PaO 2 in LPV group were significantly higher while the intraoperative A-aO 2 was clearly lower. C dyn and C stat at all the intraoperative time points in LPV group were significantly higher compared to CV group ( p < 0.05). There were no differences in the incidence of atelectasis on day one after surgery between the two groups. Conclusions Lung protective mechanical ventilation significantly improved intraoperative pulmonary oxygenation function and pulmonary compliance in patients experiencing various abdominal laparoscopic surgeries, but it could not ameliorate early postoperative atelectasis and oxygenation function on the first day after surgery. Trial registration https://www.clinicaltrials.gov/identifier: NCT04546932 (09/05/2020). | Lung-protective mechanical ventilation for patients undergoing abdominal laparoscopic surgeries: a randomized controlled trial | 10.1186/s12871-021-01318-5 |
2021-03-26 | Background Low temperature (LT) is one of the main limiting factors that affect growth and development in grape. Increasing soluble sugar and scavenging reactive oxygen species (ROS) play critical roles in grapevine resistance to cold stress. However, the mechanism of β-amylase (BAM) involved in the regulation of sugar levels and antioxidant enzyme activities in response to cold stress is unclear. Results In this study, six BAM genes were identified and clustered into four groups. Multiple sequence alignment and gene structure analysis showed that VvBAM6 lacked the Glu380 residue and contained only an exon. The transcript abundance of VvBAM1 and VvBAM3 significantly increased as temperature decreased. After LT stress, VvBAM1 was highly expressed in the leaves, petioles, stems, and roots of overexpressing tomato lines. The total amylase and BAM activities increased by 6.5- and 6.01-fold in transgenic plants compared with those in wild-type tomato plants (WT) subjected to LT, respectively. The glucose and sucrose contents in transgenic plants were significantly higher than those in WT plants, whereas the starch contents in the former decreased by 1.5-fold compared with those in the latter under LT stress. The analysis of transcriptome sequencing data revealed that 541 genes were upregulated, and 663 genes were downregulated in transgenic plants. One sugar transporter protein gene ( SlSTP10 ), two peroxidase (POD)-related genes ( SlPER7 and SlPER5 ), and one catalase (CAT)-related gene ( SlCAT1 ) were upregulated by 8.6-, 3.6-, 3.0-, and 2.3-fold in transgenic plants after LT stress, respectively. Conclusions Our results suggest that VvBAM 1 overexpression promotes ROS scavenging and improves cold tolerance ability by modulating starch hydrolysis to affect soluble sugar levels in tomato plants. | Genome-wide identification of BAM genes in grapevine (Vitis vinifera L.) and ectopic expression of VvBAM1 modulating soluble sugar levels to improve low-temperature tolerance in tomato | 10.1186/s12870-021-02916-8 |
2021-03-25 | Background K-seq, a new genotyping methodology based on the amplification of genomic regions using two steps of Klenow amplification with short oligonucleotides, followed by standard PCR and Illumina sequencing, is presented. The protocol was accompanied by software developed to aid with primer set design. Results As the first examples, K-seq in species as diverse as tomato, dog and wheat was developed. K-seq provided genetic distances similar to those based on WGS in dogs. Experiments comparing K-seq and GBS in tomato showed similar genetic results, although K-seq had the advantage of finding more SNPs for the same number of Illumina reads. The technology reproducibility was tested with two independent runs of the tomato samples, and the correlation coefficient of the SNP coverages between samples was 0.8 and the genotype match was above 94%. K-seq also proved to be useful in polyploid species. The wheat samples generated specific markers for all subgenomes, and the SNPs generated from the diploid ancestors were located in the expected subgenome with accuracies greater than 80%. Conclusion K-seq is an open, patent-unencumbered, easy-to-set-up, cost-effective and reliable technology ready to be used by any molecular biology laboratory without special equipment in many genetic studies. | K-seq, an affordable, reliable, and open Klenow NGS-based genotyping technology | 10.1186/s13007-021-00733-6 |
2021-03-25 | Background As an object’s electrical passive property, the electrical conductivity is proportional to the mobility and concentration of charged carriers that reflect the brain micro-structures. The measured multi- b diffusion-weighted imaging (M b -DWI) data by controlling the degree of applied diffusion weights can quantify the apparent mobility of water molecules within biological tissues. Without any external electrical stimulation, magnetic resonance electrical properties tomography (MREPT) techniques have successfully recovered the conductivity distribution at a Larmor-frequency. Methods This work provides a non-invasive method to decompose the high-frequency conductivity into the extracellular medium conductivity based on a two-compartment model using M b -DWI. To separate the intra- and extracellular micro-structures from the recovered high-frequency conductivity, we include higher b -values DWI and apply the random decision forests to stably determine the micro-structural diffusion parameters. Results To demonstrate the proposed method, we conducted phantom and human experiments by comparing the results of reconstructed conductivity of extracellular medium and the conductivity in the intra-neurite and intra-cell body. The phantom and human experiments verify that the proposed method can recover the extracellular electrical properties from the high-frequency conductivity using a routine protocol sequence of MRI scan. Conclusion We have proposed a method to decompose the electrical properties in the extracellular, intra-neurite, and soma compartments from the high-frequency conductivity map, reconstructed by solving the electro-magnetic equation with measured B1 phase signals. | Decomposition of high-frequency electrical conductivity into extracellular and intracellular compartments based on two-compartment model using low-to-high multi-b diffusion MRI | 10.1186/s12938-021-00869-5 |
2021-03-24 | We study the drag resistivity numerically for charge carriers in a specially separated electron-electron (e-e) bilayer system for both the symmetric and asymmetric case in weak interaction and Boltzmann regime. Interaction in Coulomb drag effect is based on Coulomb interaction in a specially separated bilayer systems. Random phase approximation (RPA) method is used to find the drag resistivity. Simply RPA method is a reliable method for high-density regime where exchange and correlation effects do not impact too much. On lowering the density, the exchange and correlation effects are significant which are included by suggesting the local field correction (LFC) in effective interlayer interactions. The drag resistivity is noticed improvement on employing the LFC. Impact of exchange and correlation based LFC increase on increasing the temperature and decreasing the concentration. Predictable behaviour is shown by the dependency of drag resistivity on temperature, density, interlayer spacing, and dielectric constant. | Study of drag resistivity in dielectric medium with the correlations effect | 10.1007/s00339-021-04422-y |
2021-03-24 | The aerodynamic design optimization of an airfoil is carried out at a transitional low Reynolds number in the framework of multi-fidelity surrogate modeling. Two multi-fidelity surrogate-based optimization methodologies are proposed. The first method involves the co-Kriging surrogate model with prediction-based high-fidelity model update strategy. The second method uses the Kriging model of the low-fidelity function, and subsequent co-Kriging modeling with high-fidelity infills done using the gradient-free trust-region approach. The high-fidelity solutions are obtained by solving the Reynolds-averaged Navier-Stokes equations with the flow transition modeled by the γ - Re θ model. The low-fidelity solutions are obtained by a panel code in conjunction with the e N method. The proposed optimization methodologies are applied to two different objective functions in the transitional low Reynolds number regime, namely, (i) maximization of lift coefficient, and (ii) maximization of endurance factor. Significant improvements in each of the objective functions are obtained using both these methodologies. | Multi-fidelity surrogate model-based airfoil optimization at a transitional low Reynolds number | 10.1007/s12046-021-01580-w |
2021-03-23 | In this research, multi-layer co-extrusion technology was adopted to prepare Polypropylene random copolymer (PPR)/Polyethylene of raised temperature resistance (PERT) composite pipes. The structures and mechanical properties of PPR/PERT composite pipe were investigated by scanning electron microscopy (SEM), Dynamic thermomechanical analysis (DMA) and impact test systematically. It was found that PPR and PERT obey different deformation mechanism at low temperature. When tested at -50 °C which is lower than the glass transition temperature ( T g ) of PPR, the molecular chains of PPR are frozen, which leads to the high notch sensitivity and extremely low impact strength of PPR/PERT pipe. Nevertheless, PERT whose T g is about -78 °C could effectively inhibit the initiation and propagation of crack and therefore improve the low-temperature toughness of PPR/PERT composite pipe significantly. Furthermore, we found that the composite pipe of PPR/PERT-2:1 could combine the stiffness of PPR and the toughness of PERT most effectively, resulting in the optimized performances of PPR/PERT pipe. | Improving the low-temperature toughness of PPR pipe by compounding with PERT | 10.1007/s10965-021-02501-5 |
2021-03-23 | Background Dust accumulation covers the leaf’s surface and influences foliar physiological activity. Two independent experiments were carried out to instigate the foliar responses to dust accumulation and the penetration limitation of small dust particles (< 1 μm) on the foliar surface, respectively. In experiment I, three dust accumulation intensities were achieved by a dust spraying treatment. Photosynthesis CO 2 exchange and fast chlorophyll fluorescence transient were measured, as well as chlorophyll contents and leaf thickness. In experiment II, the penetration limits of small particulates on the leaf surface were examined by feeding nano-fluorescent microspheres. Results Dust accumulation alleviated the photoinhibition of Photosystem II and decreased photosynthesis, as represented by net photosynthetic rates ( P N ) and stomatal conductance to water vapor ( g s ). Photosynthetic response curves between net photosynthetic rate ( P N ) and photosynthetically active radiation (PAR) showed that heavy dust accumulation (34.98 ± 2.6 mg cm − 2 ) increased the light compensation point (LCP) and light saturation point (LSP) and decreased photosynthesis rates under saturating light ( P Nmax ). Leaves became thin due to the lack of a palisade layer while chlorophyll content increased under dust accumulation. Confocal laser scanning microscopy (CLSM) images showed that the larger particles (1 μm) distributed in the regions below the stomata and the smaller ones (0.1 μm) were detected in the wider areas below stomata. Conclusions These results suggested that dust accumulation induced similar effects as shade tolerance in cotton leaves but did not trigger more photochemical acclimation to low light. Dust particles (< 1 μm) penetrated leaf surface through stomata. | Similar effects as shade tolerance induced by dust accumulation and size penetration of particulates on cotton leaves | 10.1186/s12870-021-02926-6 |
2021-03-23 | Background The extent to which income setting or rural and urban environments modify the association between sleep and obesity in young children is unclear. The aims of this cross-sectional observational study were to (i) describe and compare sleep in South African preschool children from rural low-income (RL), urban low-income (UL) and urban high-income (UH) settings; and (ii) test for associations between sleep parameters and body mass index (BMI). Methods Participants were preschoolers (5.2 ± 0.7y, 49.5% boys) from RL ( n = 111), UL ( n = 65) and UH ( n = 22) settings. Height and weight were measured. Sleep, sedentary behaviour and physical activity were assessed using accelerometery. Results UL children had higher BMI z-scores (median: 0.39; interquartile range: − 0.27, 0.99) than the UH (− 0.38; − 0.88, 0.11) and RL (− 0.08; − 0.83, 0.53) children ( p = 0.001). The UL children had later bedtimes ( p < 0.001) and wake-up times ( p < 0.001) and shorter 24 h ( p < 0.001) and nocturnal ( p < 0.001) sleep durations than the RL and UH children. After adjusting for age, sex, setting, SB and PA, for every hour less sleep obtained (24 h and nocturnal), children were 2.28 (95% CI: 1.28–4.35) and 2.22 (95% CI: 1.27–3.85) more likely, respectively, to belong to a higher BMI z-score quartile. Conclusions Shorter sleep is associated with a higher BMI z-score in South African preschoolers, despite high levels of PA, with UL children appearing to be particularly vulnerable. | Sleep and BMI in South African urban and rural, high and low-income preschool children | 10.1186/s12889-021-10591-5 |
2021-03-21 | The recently discovered and prepared honeycomb borophene is one of the many forms of borophene. For the first time, we studied the tribological properties of honeycomb borophene based on first principles and found that it has excellent tribological performance. As a two-dimensional material, honeycomb borophene has potential applications in the field of tribology. Correspondingly, we studied interlaminar charge transfer in several common heterojunctions and then explored its internal friction mechanism. The present work indicts that honeycomb borophene, a new type of two-dimensional material, may help broaden the research field of two-dimensional materials in tribology. | Ultra-Low Friction of Graphene/Honeycomb Borophene Heterojunction | 10.1007/s11249-021-01418-w |
2021-03-16 | Due to the increased processing data rates, which is required in applications such as fifth-generation (5G) wireless networks, the battery power will discharge rapidly. Hence, there is a need for the design of novel circuit topologies to cater the demand of ultra-low voltage and low power operation. In this paper, a low-noise amplifier (LNA) operating at ultra-low voltage is proposed to address the demands of battery-powered communication devices. The LNA dual shunt peaking and has two modes of operation. In low-power mode (Mode-I), the LNA achieves a high gain ( $$S21$$ S 21 ) of 18.87 dB, minimum noise figure ( $${NF}_{min.}$$ NF m i n . ) of 2.5 dB in the − 3 dB frequency range of 2.3–2.9 GHz, and third-order intercept point (IIP3) of − 7.9dBm when operating at 0.6 V supply. In high-power mode (Mode-II), the achieved gain, NF, and IIP3 are 21.36 dB, 2.3 dB, and 13.78dBm respectively when operating at 1 V supply. The proposed LNA is implemented in UMC 180 nm CMOS process technology with a core area of $$0.40{\mathrm{ mm}}^{2}$$ 0.40 mm 2 and the post-layout validation is performed using Cadence SpectreRF circuit simulator. | A 219-µW ultra-low power low-noise amplifier for IEEE 802.15.4 based battery powered, portable, wearable IoT applications | 10.1007/s42452-021-04402-0 |
2021-03-13 | This article describes a 135-m-thick sequence collection from the lower Eocene limestones of the Dungul Formation that caps the Sinn El-Kaddab Plateau in the Kurkur area. A sedimentological evolution model of these limestones has been constructed for the first time primarily based totally on lithology, microfacies analysis, SEM microscopy, and EDAX microchemical analyses. This carbonate sequence has been subdivided into three shallowing-upward facies. The hemipelagic facies at the base is dominated by foraminiferal wackestone, unconformably overlain by shallow offshore facies dominated by larger benthic foraminiferal grainstone and packstone, and capped by middle ramp facies dominated by bioclastic grainstone and packstone. These facies are analog of the Eocene facies of the Tethys Sea that had been formerly defined from Libya, Tunisia, Spain, and Kirkuk oil field in Iraq. Results suggest deposition in a basin characterized by oscillation in relief, in response to tectonic uplifting coupled with eustatic sea fluctuations associated with and the Syrian arching system. The limestones exhibit four successive diagenetic stages. The first stage is early marine diagenesis with the formation of micrite rim cement and preferential micritization of some skeletal grains. The second stage is shallow burial diagenesis, compaction, drusy calcite cement, and silicification. The third stage is meteoric diagenesis, the formation of isopachous calcite rim cement, dissolution and formation of blocky cement. The fourth stage is vadose diagenesis which includes karstification and ferrugination with iron oxy-hydroxides impregnation. | Sedimentological evolution and diagenesis of lower Eocene limestones, the Sinn El-Kaddab Plateau, the southern extent of the Tethys Sea in Egypt | 10.1007/s12517-021-06844-7 |
2021-03-12 | Background Low temperature (LT) often occurs at the seedling stage in the early rice-growing season, especially for direct seeded early-season indica rice, and using flooding irrigation can mitigate LT damage in rice seedlings. The molecular mechanism by which flooding mitigates the damage induced by LT stress has not been fully elucidated. Thus, LT stress at 8 °C, LT accompanied by flooding (LTF) and CK (control) treatments were established for 3 days to determine the transcriptomic, proteomic and physiological response in direct seeded rice seedlings at the seedling stage. Results LT damaged chloroplasts, and thylakoid lamellae, and increased osmiophilic bodies and starch grains compared to CK, but LTF alleviated the damage to chloroplast structure caused by LT. The physiological characteristics of treated plants showed that compared with LT, LTF significantly increased the contents of rubisco, chlorophyll, PEPCK, ATP and GA 3 but significantly decreased soluble protein, MDA and ABA contents. 4D-label-free quantitative proteomic profiling showed that photosynthesis-responsive proteins, such as phytochrome, as well as chlorophyll and the tricarboxylic acid cycle were significantly downregulated in LT/CK and LTF/CK comparison groups. However, compared with LT, phytochrome, chlorophyllide oxygenase activity and the glucan branching enzyme in LTF were significantly upregulated in rice leaves. Transcriptomic and proteomic studies identified 72,818 transcripts and 5639 proteins, and 4983 genes that were identified at both the transcriptome and proteome levels. Differentially expressed genes (DEGs) and differentially expressed proteins (DEPs) were significantly enriched in glycine, serine and threonine metabolism, biosynthesis of secondary metabolites, glycolysis/gluconeogenesis and metabolic pathways. Conclusion Through transcriptomic, proteomic and physiological analyses, we determined that a variety of metabolic pathway changes were induced by LT and LTF. GO and KEGG enrichment analyses demonstrated that DEGs and DEPs were associated with photosynthesis pathways, antioxidant enzymes and energy metabolism pathway-related proteins. Our study provided new insights for efforts to reduce the damage to direct seeded rice caused by low-temperature stress and provided a breeding target for low temperature flooding-resistant cultivars. Further analysis of translational regulation and metabolites may help to elucidate the molecular mechanisms by which flooding mitigates low-temperature stress in direct seeded early indica rice at the seedling stage. | Transcriptomic, proteomic, and physiological comparative analyses of flooding mitigation of the damage induced by low-temperature stress in direct seeded early indica rice at the seedling stage | 10.1186/s12864-021-07458-9 |
2021-03-12 | Rice growth is sensitive to low temperature. Chilling injury is one of the main natural disasters in rice cultivation, and is damaging to rice growth at all developmental stages. Low-temperature germinability (LTG) is an important trait for seedling establishment, especially in rice direct-sowing practice. However, the genetic mechanism of LTG remains elusive. Here, we report the mapping of QTLs controlling LTG in rice using 586 single segment substitution lines (SSSL) derived from 4 AA-genome wild rice species. 21 SSSLs with the highest germination rate at low temperature in both of the two tested seasons were selected, from them 10 QTLs controlling LTG were identified by substitution mapping to locate on 6 chromosomes: chromosome 1, 3, 5, 7, 8 and 11, with an interval length of 3.45 to 20.15 cM. Five QTLs were detected from Niv-SSSls: qLTGn3-1 , qLTGn5-1 , qLTGn5-3 , qLTGn7-1 and qLTGn7-2 , their additive effects ranged from 3.72% to 19.74% in late season 2018. qLTGb1-1 and qLTGb8-2 were detected in the SSSLs with O. barthii as the donor and they accounted for at least 9.51% of the total phenotypic variation. Two QTLs, qLTGg5-2 and qLTGg8-1 , were derived from O. glumaepatula, and their average additive effects were 4.28% and 20.39% in late seasons 2018, respectively. qLTGm11-1 on chromosome 11 was the only QTL identified from O. meridionalis . All QTLs derived from wild rice species improved low-temperature germination significantly. The SSSL library with wild rice species as donor is therefore a valuable resource for rice germplasm innovation and the breeding of chilling-resistant varieties. | Mapping QTLs controlling low-temperature germinability in rice by using single segment substitution lines derived from 4 AA-genome species of wild rice | 10.1007/s10681-021-02791-2 |
2021-03-12 | Background Low-density lipoprotein cholesterol (LDL-C) is one of the most important types of cholesterol and has an impact on health. Certain lifestyle and dietary habits in different populations may leads to increased levels of LDL-C, particularly among those with poor education and economic statuses, such as hill tribe people in Thailand. This study aimed to estimate the prevalence of and determine the factors associated with high LDL-C levels among hill tribe people in northern Thailand. Methods A cross-sectional study was performed to gather information from six main hill tribe populations: Akha, Lahu, Hmong, Yao, Karen, and Lisu. Individuals who were aged over 30 years and living in 30 selected hill tribe villages were invited to participate in the study. A validated questionnaire and 5-mL blood specimens were used to obtain data. Correlation analyses, chi-square tests, t-tests, and logistic regression were used to detect correlations and associations. Results A total of 2552 participants were recruited into the study; 65.9% were females, and 64.1% were aged younger than 60 years old. Approximately 69.6% of participants had abnormal LDL-C levels; 33.6% had above-optimal levels, 24.3% had borderline high levels, 8.0% had high levels, and 3.7% had very high levels. A total of 17.4% of participants had low high-density lipoprotein cholesterol (HDL-C) and high LDL-C levels, while 14.9% had high triglyceride and LDL-C levels. After controlling for sex, age, religion, education, annual family income, and marital status in the multivariate model, three variables were found to be associated with high LDL-C levels: occupation, the amount of lard used in daily cooking, and glycated hemoglobin (HbA1c). Those who were working as agriculturalists had a 1.34-fold greater chance of having abnormal LDL-C than traders and others (95% CI = 1.09–1.34). Those who used moderate and high quantities of lard in their daily cooking had a 1.45-fold (95% CI = 1.15–1.82) and 1.31-fold (95% CI = 1.04–1.68) greater likelihood of having abnormal LDL-C levels than those who used low quantities, respectively. Those who had abnormal HbA1c levels were less likely to develop abnormal LDL-C levels than those who had normal HbA1c levels (AOR = 0.69, 95% CI = 0.51–92). Conclusions Effective public health programs that do not conflict with the cultures of hill tribes are urgently needed, particularly programs encouraging the use of small quantities of lard for daily cooking practices. | Factors associated with elevated low-density lipoprotein cholesterol levels among hill tribe people aged 30 years and over in Thailand: a cross-sectional study | 10.1186/s12889-021-10577-3 |
2021-03-12 | Background Locked twins is a rare and hazardous obstetric complication, which occurs in approximately 1:1000 twin pregnancies. One of the known etiologic factors for locked twins is size of the twins. We report a case of chin-to-chin locked twins that occurred at gestational age of 30 weeks pus 6 days. Case summary A 27 years-old primigravida Ethiopian mother presented with a history of pushing down pain and passage of liquor of 6 hours duration at gestational age of 30 weeks plus 6 days. With a diagnosis of twin pregnancy (first twin non-vertex), abdominal delivery was decided in latent first stage of labor but mother refused caesarian delivery and she was allowed to labor with the hope of achieving a vaginal delivery. In second stage, interlocking twin was encountered and a low vertical cesarean section was done to effect delivery of twins without the need to decapitate the first twin. Conclusion Locked twin is a rare obstetric complication. Whenever it is encountered, successful delivery can be achieved without the need to have decapitation of the first twin during caesarian section. | Locked twins—remote from term: a case report | 10.1186/s13256-021-02725-5 |
2021-03-12 | The study of the lower limit of filling of the pore throat in tight sandstone reservoirs is an essential part of reservoir evaluation. It can guide exploration and development and helps understand tight oil accumulation and estimate saturation. Determining this lower limit of pore throat filling has mainly been based on experience in a particular reservoir or field, and there is a lack of theoretical and experimental support. In this paper, the lower limit of pore throat filling of the tight sandstone reservoir in the Gaotaizi oil layer in the Zijia area is theoretically derived. Experiments show that oil charging at the source-reservoir interface is affected by the increasing pressure within the reservoir due to hydrocarbon generation. Based on the equilibrium relationship between the hydrodynamic effects and the actual reservoir parameters, the theoretical derivation of the lower limit of the pore throat diameter at the source-reservoir interface is 23.6 nm. The mechanical mechanism of the internal charging of the reservoir is different from the source-reservoir interface. In this paper, the lower limit of the pore throat filling in the Gaotaizi reservoir is 54.45 nm based on environmental scanning electron miscopy and the energy spectrum. Combined with the analysis of mercury injection tests, the lower limit of the filling pore throat is used to determine that oil saturation near the source-reservoir interface is 33%, and 19% within the reservoir. The results of the study on the lower limit of pore throat filling in different parts of the reservoir provide a theoretical basis and prediction method for the distribution and target evaluation of tight oil sandstone. | Study of the lower limit of pore throat filling in tight sandstone reservoir of Gaotaizi oil layer in Qijia area | 10.1007/s12517-021-06785-1 |
2021-03-10 | Spectroscopic observations at extreme- and far-ultraviolet wavelengths have revealed systematic upflows in the solar transition region and corona. These upflows are best seen in the network structures of the quiet Sun and coronal holes, boundaries of active regions, and dimming regions associated with coronal mass ejections. They have been intensively studied in the past two decades because they are likely to be closely related to the formation of the solar wind and heating of the upper solar atmosphere. We present an overview of the characteristics of these upflows, introduce their possible formation mechanisms, and discuss their potential roles in the mass and energy transport in the solar atmosphere. Although past investigations have greatly improved our understanding of these upflows, they have left us with several outstanding questions and unresolved issues that should be addressed in the future. New observations from the Solar Orbiter mission, the Daniel K. Inouye Solar Telescope , and the Parker Solar Probe will likely provide critical information to advance our understanding of the generation, propagation, and energization of these upflows. | Upflows in the Upper Solar Atmosphere | 10.1007/s11207-021-01792-7 |
2021-03-10 | Monitoring sea level is critical due to climate change observed over the years. Global Navigation Satellite System Reflectometry (GNSS-R) has been widely demonstrated for coastal sea-level monitoring. The use of signal-to-noise ratio (SNR) observations from ground-based stations has been especially productive for altimetry applications. SNR records an interference pattern whose oscillation frequency allows retrieving the unknown reflector height. Here we report the development and validation of a complete hardware and software system for SNR-based GNSS-R. We make it available as open source based on the Arduino platform. It costs about US$200 (including solar power supply) and requires minimal assembly of commercial off-the-shelf components. As an initial validation towards applications in coastal regions, we have evaluated the system over approximately 1 year by the Guaíba Lake in Brazil. We have compared water-level altimetry retrievals with independent measurements from a co-located radar tide gauge (within 10 m). The GNSS-R device ran practically uninterruptedly, while the reference radar gauge suffered two malfunctioning periods, resulting in gaps lasting for 44 and 38 days. The stability of GNSS-R altimetry results enabled the detection of miscalibration steps (10 cm and 15 cm) inadvertently introduced in the radar gauge after it underwent maintenance. Excluding the radar gaps and its malfunctioning periods (reducing the time series duration from 317 to 147 days), we have found a correlation of 0.989 and RMSE of 2.9 cm in daily means. To foster open science and lower the barriers for entry in SNR-based GNSS-R research and applications, we make a complete bill of materials and build tutorials freely available on the Internet so that interested researchers can replicate the system. | An open-source low-cost sensor for SNR-based GNSS reflectometry: design and long-term validation towards sea-level altimetry | 10.1007/s10291-021-01087-1 |
2021-03-08 | Gold-enhanced mechanical exfoliation method attracts broad interests in recent years, which has been widely used for preparing large-area and high-quality 2D single crystals. Even many calculations predict that there is strong interaction between Au film and the exfoliated 2D crystals, direct experimental evidence is still lacking. Here, we perform Raman spectroscopy measurements for few layer MoS 2 with and without Au film underneath. The main peaks of MoS 2 on Au film show no obvious change at higher frequency, however, the breathing and shear modes at low-frequency are suppressed, especially for breathing modes. In contrast, both breathing modes and shear modes can be detected on suspended MoS 2 and the samples are transferred from Au film to SiO 2 /Si. These comparison results provide direct evidence for the existence of covalent-like quasi-bonding at the interface of Au film and the exfoliated MoS 2 crystal. This MoS 2 /Au interface interaction presents a special pinning-effect for low-frequency rigid vibration. Similar pinning-effect is also discovered in WS 2 /Au system. Our work reports the suppression of low-frequency Raman modes of MoS 2 , WS 2 on Au film, which will deliver new inspiration for studying other interactions between layered materials and solid surfaces. | Raman spectra evidence for the covalent-like quasi-bonding between exfoliated MoS2 and Au films | 10.1007/s11432-020-3173-9 |
2021-03-08 | With the development of human civilization, the demand for resources and the collision with nature are becoming more and more intense. After the burning of fossil fuels, land use has become another major impact plate of atmospheric carbon content. At the same time, it is also the initiator of global change. As a new solution to the new era, the interaction between low-carbon economic model and land use has been pushed to the forefront of global scholars’ discussion. Since the reform and opening up, China’s land use form and corresponding proportion have changed significantly. The rapid conversion of agricultural land to construction land has resulted in a large proportion of construction land, and the original land structure has been deformed too fast, resulting in the rapid destruction of the original carbon emission model and structure. The main reason is that the economic income is put in the first place of land use, ignoring the destruction of carbon cycle balance and the impact on carbon balance caused by this change. With the concept of sustainable development put forward, low-carbon economic development model will occupy an important position in accelerating the process of urbanization in China. For how to evaluate the indicators of low-carbon economy, this paper first establishes a system and fully considers the development status and economic status of each urban agglomeration. For the evaluation of low-carbon economy, this paper adopts the method of decomposition and analysis of all levels and uses real-time large data of urban agglomeration land use to study and analyze the utilization efficiency. Finally, combined with the data obtained by the above two methods, through the application of GIS correlation analysis method, the contribution of low-carbon economic model to economic development is obtained, and the correlation degree and influence state between them are obtained. | RETRACTED ARTICLE: Relationship between land use carbon emission and economic growth based on GIS | 10.1007/s12517-021-06794-0 |
2021-03-02 | Broadband photodetector has wide applications in the field of remote sensing, health monitoring and medical imaging. Two-dimensional (2D) materials with narrow bandgaps have shown enormous potential in broadband photodetection. However, the device performance is often restricted by the high dark currents. Herein, we demonstrate a high performance broadband photodetector by constructing Bi 2 O 2 Se/BP van der Waals heterojunction. The device exhibits a p-n diode behavior with a current rectification ratio of ∼20. Benifited from the low dark current of the heterojunction and the effective carrier separation, the device achieves the responsivity ( R ) of ∼ 500 A/W, ∼ 4.3 A/W and ∼ 2.3 A/W at 700 nm, 1310 nm and 1550 nm, respectively. The specific detectivity ( D *) is up to ∼ 2.8 × 10 11 Jones (700 nm), ∼ 2.4 × 10 9 Jones (1310 nm) and ∼ 1.3 × 10 9 Jones (1550 nm). Moreover, the response time is ∼ 9 ms, which is more than 20 times faster than that of individual BP (∼ 190 ms) and Bi 2 O 2 Se (∼ 180 ms) devices. | Bi2O2Se/BP van der Waals heterojunction for high performance broadband photodetector | 10.1007/s11432-020-3101-1 |
2021-03-01 | Gasification or combustion of coal and biomass is the most important form of power generation today. However, the use of coal/biomass at high temperatures has an inherent problem related to the ash generated. The formation of ash leads to a problematic phenomenon called slagging. Slagging is the accumulation of molten ash on the walls of the furnace, gasifier, or boiler and is detrimental as it reduces the heat transfer rate, and the combustion/gasification rate of unburnt carbon, causes mechanical failure, high-temperature corrosion and on occasions, superheater explosions. To improve the gasifier/combustor facility, it is very important to understand the key ash properties, slag characteristics, viscosity and critical viscosity temperature. This paper reviews the content, compositions, and melting characteristics of ashes in differently ranked coal and biomass, and discusses the formation mechanism, characteristics, and structure of slag. In particular, this paper focuses on low-rank coal and biomass that have been receiving increased attention recently. Besides, it reviews the available methodologies and formulae for slag viscosity measurement/prediction and summarizes the current limitations and potential applications. Moreover, it discusses the slagging behavior of different ranks of coal and biomass by examining the applicability of the current viscosity measurement methods to these fuels, and the viscosity prediction models and factors that affect the slag viscosity. This review shows that the existing viscosity models and slagging indices can only satisfactorily predict the viscosity and slagging propensity of high-rank coals but cannot predict the slagging propensity and slag viscosity of low-rank coal, and especially biomass ashes, even if they are limited to a particular composition only. Thus, there is a critical need for the development of an index, or a model or even a measurement method, which can predict/measure the slagging propensity and slag viscosity correctly for all low-rank coal and biomass ashes. | A critical review of ash slagging mechanisms and viscosity measurement for low-rank coal and bio-slags | 10.1007/s11708-020-0807-8 |
2021-03-01 | In this paper, an investigation on the low-velocity impact (LVI) response of a shear deformable beam laminated by carbon nanotube reinforced composite (CNTRC) layers is performed. The composite beam is “auxetic” due to the negative out-of-plane Poisson’s ratio (NPR) through special symmetric stacking sequences of layers that are designed based on the Classical Laminate Theory. To study the effect of the out-of-plane NPR on the LVI response of the composite beam, a newly defined Hertz model is developed. The motion equations of Kármán type for the CNTRC laminate beam are derived in the framework of the Reddy beam theory and solved by means of a two-step perturbation approach while the dynamic equation of the impactor is built on Newton’s Law. Since temperature-dependent material properties of both carbon nanotube (CNT) and matrix are employed, the thermal influence on the LVI behavior is also investigated. Moreover, a piece-wise method is employed herein to investigate the effect of functionally graded (FG) patterns of the CNT reinforcements on the impact response. Numerical results elucidating the effects of temperature, FG distribution, and CNT volume fraction on the out-of-plane Poisson’s ratio and impact response of the beam are obtained by using a Range–Kutta method and discussed in details. | The effect of negative Poisson’s ratio on the low-velocity impact response of an auxetic nanocomposite laminate beam | 10.1007/s10999-020-09521-x |
2021-03-01 | TURKSAT-3USAT is the first Turkish communication 3U CubeSat designed and built by the students of the Space Systems Design and Test Laboratory and Radio Frequency Electronics Laboratory of Istanbul Technical University (ITU). Students partnered with TURKSAT, A.S. Company as well as the Turkish Amateur Technology Organization, when creating the design. The payload of TURKSAT-3USAT, having dimensions of 10 × 10 × 34 cm 3 , is an amateur band VHF/UHF transponder that will be used for voice communication. In this study, a thermal control system of TURKSAT-3USAT at 680 km altitude was presented. TURKSAT-3USAT used both passive and active thermal control. The thermal model of CubeSat was constructed and analyzed using ThermXL and ESATAN-TMS thermal analysis tools. The temperature results showed that all electronic components were within their allowed temperature range, except the batteries. For batteries, heaters are recommended during the cold case condition. Thermal cycling and bake-out testing were carried out on the flight model in a thermal vacuum chamber. | Thermal design, analysis, and testing of the first Turkish 3U communication CubeSat in low earth orbit | 10.1007/s10973-021-10566-z |
2021-03-01 | Wireless body sensor networks are becoming a ubiquitous solution to preventing chronic illnesses for a population with an ever-increasing number of elderly people. Through constant and real-time health monitoring, caregivers and medical personnel, and even patients themselves, can act more quickly in the event of a critical situation. The design of wireless body sensors must have several characteristics that enable their integration into the wearer’s life as seamlessly and unobtrusively as possible. Thus, how these sensors are powered becomes a topic of interest. Much research and work have been conducted on using thermoelectric generators to convert the waste heat from human metabolic activities into useful electricity to perpetually power these devices. The concept of an effective wireless body sensor network is also studied in this work. Analytical approaches are applied to a commercial module as an energy-scavenging device based on data gathered from a wide literature review. The ideal model is further optimized using a dimensionless approach to determine the feasibility of the optimized device in terms of implementation and performance. Finally, a design that considers all parameters of an effective energy-scavenging device is proposed alongside work for the future. | Wearable thermoelectric generators as energy harvesters for wireless body sensors | 10.1007/s40095-020-00365-x |
2021-03-01 | Quantitative assessment of non-Masing behavior is studied, and a new method is proposed for the estimation of cyclic plastic strain energy density and fatigue life. Low cycle fatigue tests were performed on 304L stainless steel employing strain amplitudes ranging from ±0.25% to ±1.0% at a strain rate of 3 × 10 -3 s -1 . The material exhibited Masing behavior at lower strain amplitudes and non-Masing behavior at higher strain amplitudes. Secondary hardening was observed at relatively higher strain amplitudes. Both the secondary hardening and non-Masing response were found to be associated with the deformation induced martensitic transformation. The master curve approach, which is generally used for the analysis of non-Masing response, could not be used as experimental data could not be represented in the form of a master curve. The proposed method of quantification of non-Masing response could estimate the cyclic plastic strain energy density of 304L stainless steel well within a scatter band of 1.2. The fatigue life of 304L stainless steel could also be predicted within a scatter band of 2. The proposed approach could also estimate the cyclic plastic strain energy density and fatigue life of materials of different grades within scatter factors of 1.2 and 2, respectively. | Quantitative Assessment and Analysis of Non-Masing Behavior of Materials under Fatigue | 10.1007/s11665-021-05494-w |
2021-03-01 | With the grouting material as focus, this study aims to guarantee that the joint with tenon and mortise constructing a metro station has the necessary waterproof performance, which shall not be poorer than the mechanical properties of the concrete with joints itself, and fine structural integrity. With groutability at low-temperature and available operational time as basis, low-temperature epoxy was selected as the grouting material for the joints. The silica powder of particular particle size and mass was added for modifying the physical performance of grouting material. A series of physical and mechanical tests were conducted in an attempt to achieve the optimal particle size and mix ratio provided that costs were reduced as practically as possible. Also, the flexural capacity of the joint filled with the above grouting material was demonstrated via the combined equal-proportion joint axial bend test. | An experimental study of modified physical performance test of low-temperature epoxy grouting material for grouting joints with tenon and mortise | 10.1007/s10845-020-01664-0 |
2021-03-01 | In the process of fatigue loading, the segregation of solid solution elements makes dislocations continuously pile-up in ferrite lath to form subgrain, which improves the fatigue properties. In this study, the low cycle fatigue properties of two kinds of Cr-Mo tempered martensitic steels with different grain sizes were investigated at 350 °C. Then, the fracture morphology and the subgrain of ferrite lath were analyzed. The results show that the low cycle fatigue life of 90H steel is significantly higher than that of 80H steel, and a large number of secondary cracks are found in the fatigue fracture. The reason is that the segregation of solid solution atoms affects the dislocations movement during low cycle fatigue. And the finer lath subgrain structure of 90H steel makes it easier to occur in grain. Thus, the evolution process of subgrain structures is changed, and the crack propagation is hindered, resulting in a large number of secondary cracks, which improves the fatigue life. In addition, the segregation effect on fatigue life decreased with the strain amplitude increasing. | Strengthening Mechanism of Low Cycle Fatigue Resistance for Cr-Mo Tempered Martensite Steel at 350 °C | 10.1007/s11665-021-05482-0 |
2021-03-01 | Ceramic bricks based on low-melting clay and ferro-dust from self-disintegrating, low-carbon, ferrochrome slags, graded from M100 to M175, respectively, were obtained in the temperature range 950 – 1100°C. The highest grades are in bricks fired at the temperatures 1050 and 1100°C, respectively, M150 and M175, which can be used as earthquake-resistant. Studies have shown that hematite, wollastonite, diopside and a liquid phase appear at brick firing temperature 950°C. Raising the firing temperature to 1000°C contributes to the appearance of anorthite and cristobalite. Raising the firing temperature to 1050°C does not bring about any special changes, except for an increase in the content of cristobalite and anorthite and a decrease in the content of feldspar. Subsequent raising of the firing temperature to 1100°C results in higher content of anorthite, diopside and cristobalite. The physicomechanical indicators increase due to the formation of anorthite and diopside in the samples. | Phase Composition and Physico-Mechanical Properties at Different Firing Temperatures of Ceramic Earthquake-Resistant Bricks with the Use of Ferro-Dust | 10.1007/s10717-021-00336-6 |
2021-03-01 | With the signing of the Minamata Convention, widespread disposal of mercury metal waste is anticipated in the near future. Due to its environmental effects, mercury metal waste must be stabilized prior to disposal as its mercuric sulfide form and/or solidified with a polymer or cement to reduce leaching and volatilization. This study investigates the long-term leaching and volatilization behaviors from processed mercury waste. Mercury metal waste specimens are stabilized with sulfide and subsequently solidified with either a sulfur polymer or one of three types of low-alkaline cement. The long-term leaching rates from the solidified mercury metal waste specimens as well as the effects of pH and temperature on leaching behavior are evaluated. The long-term volatilization rates of gaseous mercury are also calculated at different temperatures. Mathematical models for mercury leaching, volatilization rates, and their parameters are established to predict the long-term behavior of stabilized, solidified waste mercury in landfill sites. | Long-term leaching and volatilization behavior of stabilized and solidified mercury metal waste | 10.1007/s10163-020-01170-8 |
2021-03-01 | Wafer-level solid liquid interdiffusion (SLID) bonding, also known as transient liquid-phase bonding, is becoming an increasingly attractive method for industrial usage since it can provide simultaneous formation of electrical interconnections and hermetic encapsulation for microelectromechanical systems. Additionally, SLID is utilized in die-attach bonding for electronic power components. In order to ensure the functionality and reliability of the devices, a fundamental understanding of the formation and evolution of interconnection microstructures, as well as global and local stresses, is of utmost importance. In this work a low-temperature Cu-In-Sn based SLID bonding process is presented. It was discovered that by introducing In to the traditional Cu-Sn metallurgy as an additional alloying element, it is possible to significantly decrease the bonding temperature. Decreasing the bonding temperature results in lower CTE induced global residual stresses. However, there are still several open issues to be studied regarding the effects of dissolved In on the physical properties of the Cu-Sn intermetallics. Additionally, partially metastable microstructures were observed in bonded samples that did not significantly evolve during thermal annealing. This indicates the Cu-In-Sn SLID bond microstructure is extremely stable. | Wafer Level Solid Liquid Interdiffusion Bonding: Formation and Evolution of Microstructures | 10.1007/s11664-020-08530-y |
2021-03-01 | The results of experimental research of low temperatures influence on mechanical characteristics of structural steels of long-term operation in chemically aggressive environments of cooling systems are presented. It is shown that such characteristics of pipe steel as impact toughness (according to Charpy), critical coefficient of stress intensity (fracture toughness), critical crack opening, and microscopic resistance significantly decrease when temperature changes from 20 to -50°C, which indicates a significant decrease in crack resistance of the material. It has been established that the indices of ductile-plastic properties – yield strength, relative longitudinal and transverse deformations decrease sharply in the process of prolonged (up to 30 years) operation of pipe steel. At the same time, intensive flooding of metal takes place. | Some Mechanical Characteristics of Structural Steels of Cooling Systems of Continuous Operation | 10.1007/s11223-021-00285-z |
2021-03-01 | Low-cost plant and algal biomass are increasingly demanded as a source of proteins, and also, peptides and amino acids are gaining interest for their biological and functional properties. The reduction in chemicals, time and energy, and the integral valorization of the raw materials in the framework of biorefineries are major concerns in the development of environmentally friendly processes. Subcritical water technology is an efficient green technique useful both for extraction and for hydrolysis of protein and other fractions (lipid, carbohydrates, phenolics). However, adequate selection of operational conditions is needed in order both to maximize their extraction yield and to avoid degradation into monomeric units and decomposition products. This review summarizes the major features of subcritical water–based processes for the extraction/hydrolysis of protein. In order to valorizate other valuable fractions from agro-food wastes and algal biomass, optimal conditions should be established as a compromise solution. Alternatively, stagewise operation to sequentially obtain the target fractions could be desirable. | Subcritical Water for the Extraction and Hydrolysis of Protein and Other Fractions in Biorefineries from Agro-food Wastes and Algae: a Review | 10.1007/s11947-020-02536-4 |
2021-03-01 | The effect of adding the oxide Nd 2 O 3 (0.1 – 3.0 mol.%) on the synthesis conditions, crystallization, and spectral properties of a thermostable Li 2 O–Al 2 O 3 –SiO 2 (LAS) sitall was studied. The introduction of up to 1 mol.% Nd 2 O 3 no effect on the crystallization properties and the precipitation of the main crystalline phase of β-eucryptite-like solid solutions Li x Al x Si 1– x O 2 , whereas increasing the Nd 2 O 3 molar content to 3% significantly changes the nature of the crystallization of LAS glass. The obtained results show that the optical sitalls with near-zero CLTE, activated by neodymium ions right up to the level N Nd 3 + ∼ 4 × 10 20 cm − 3 $$ {N}_{\mathrm{Nd}}^{3+}\sim 4\times {10}^{20}{\mathrm{cm}}^{-3} $$ , can be regarded as a base for producing new light-emitting thermostable optical media. | Thermostable Transparent Lithium-Aluminosilicate Sitall Doped with Neodymium Oxide | 10.1007/s10717-021-00322-y |
2021-03-01 | The low-temperature sinterability of TiO 2 –CuO systems was examined through a two-step sintering process. The first-step heat treatment was carried out at 900 °C for either 5 min or 1 h. The subsequent second-step sintering by reheating after cooling proceeded at 800 °C for various times. Micron-sized (2 µm) powders as received were used as the starting materials. In the present system, the densification behaviors through grain-boundary diffusion were similar to those in nanocrystalline ceramics at low temperatures. The difference in temperature sensitivity for densification or grain growth was thus exploited to enhance densification and hinder grain growth. As a result, enhanced densification without notable grain growth was achieved after second-step sintering, as opposed to conventional sintering at 800 °C. This implies that the grain-boundary diffusion contributing to densification was more active than the grain-boundary migration at 800 °C. In this regard, the current results show a trait of activated sintering as well. | Low-temperature sintering behaviors in a titanium oxide–copper oxide system through two-step heat treatment | 10.1007/s43207-020-00092-3 |
2021-03-01 | Abstract The effect of gamma-irradiation with doses of 5, 10, 15, and 20 Mrad on the mechanical characteristics of a polymer composite material has been studied. It has been shown that an increase in the radiation dose leads to an increase in the breaking stress and a decrease in the breaking strain. Toughness values have been calculated, from which it follows that the strength of the investigated samples (toughness) increases with increasing radiation dose, reaching a maximum at 20 Mrad. An increase in the test temperature leads to a sharp decrease in the toughness. Irradiation with gamma-rays to a dose of 20 Mrad leads to the material acquiring the properties of ebonite, as indicated by a sharp decrease in the breaking strain and an increase in the breaking stress. | Mechanical Characteristics of a Polymer Composite Material Based on Gamma-Irradiated Low-Molecular-Weight Rubbers | 10.1134/S0018143921020107 |
2021-03-01 | Li 3 VO 4 particles anchored on reduced graphene oxide hybrid (Li 3 VO 4 /rGO) are firstly fabricated through a solvent thermal method at low temperature and atmospheric pressure. In the Li 3 VO 4 /rGO, rGO reduces the particle size of Li 3 VO 4 and improves the electronic conductivity of the hybrid, resulting in excellent reaction kinetics and high pseudocapacitive charge storage of 69.3%, giving rise to superb electrochemical performance as anode for Li-ion batteries. After 200 cycles at 0.15 A g −1 , the Li 3 VO 4 /rGO electrode delivers high discharge capacity of 410.7 mAh g −1 , which is distinctly improved than that of pristine Li 3 VO 4 obtained under similar condition (274.1 mAh g −1 after 200 cycles). Moreover, the Li 3 VO 4 /rGO electrode also exhibits excellent rate capability, showing high discharge capacity of 249.5 mAh g −1 at a specific current of 1.6 A g −1 . The low temperature and atmospheric pressure fabrication approach is easy to scale up, which is advantageous for practical application. | Low temperature and atmospheric pressure fabrication of Li3VO4/rGO hybrid as high-performance anode for lithium-ion batteries | 10.1007/s11581-020-03896-9 |
2021-03-01 | Composite substrates of linear low-density polyethylene with thermotropic liquid crystals as inclusions with three different weight fractions were synthesized. The dielectric characterizations of the composites in X band frequencies were studied to assess their applicability as substrates for microwave devices. Thermotropic liquid crystals, NN-(terephthalylidene)bis(4- n -butylaniline), NN-(terephthalylidene)bis(4- n -hexylaniline) and NN-(terephthalylidene)bis(4- n -decylbenzamine) were synthesized in the laboratory at room temperature. Structural characterization for synthesized thermotropic liquid crystals was done using nuclear magnetic resonance and Fourier transform infrared spectroscopy. To confirm the distribution of liquid crystal inclusions in the polymer matrix, scanning electron microscope images were used. Water absorbance test was carried out following Archimedes’ principle. The real part of complex permittivity and the dielectric loss tangent at X band frequencies for all the weight fractions of the composite were found to be ~ 2.1–2.4 and ~ 10 −2 –10 −4 respectively. The magnetic loss tangent was also measured for the substrates and showed values within the range of 10 −1 –10 −2 . To establish the suitability of the fabricated substrates for use in antennas, the return losses were calculated using the complex permittivity and permeability values. | Linear Low Density Polyethylene-Thermotropic Liquid Crystal Composite Substrate for High-Frequency Devices: Dielectric Characterization | 10.1007/s11664-020-08626-5 |
2021-03-01 | The authors have presented results of synthesis of carbon nanotubes from low-density polyethylene. The synthesis was carried by thermal destruction of the polyethylene in a chemical-vapor-deposition unit. The process of decomposition of the polyethylene and the synthesis of carbon nanotubes were implemented in one stage in a triple-fired furnace for chemical vapor deposition. Consideration has been given to the influence of temperature on the decomposition products of polyethylene in the range of temperatures 450–550oC. The gas- and vaporphase decomposition products of polyethylene, obtained at different temperatures, were investigated by the infrared spectroscopy method. It has been established that the necessary and suffi cient temperature of decomposition of polyethylene is 450oC. Carbon nanotubes were grown on a catalyst that represented cenospheres impregnated with a ferrous nitrate solution. On exposure to high temperatures, ferrous nitrate decomposes to form pure iron particles on the cenospheric surface, which are active sites of growth of carbon nanotubes. The formation of iron particles on the cenospheric surface upon the impregnation with ferrous nitrate and thermal treatment is confirmed by the results of x-ray phase analysis. A semiquantitative analysis shows that the content of iron in the total catalysts mass amounts to about 2.3%. The synthesis gives rise to carbon nanotubes with diameters of 50–60 nm on the cenospheric surface. Thus, it has been shown that carbon nanotubes can be synthesized from low-density polyethylene waste. | Recycling of Low-Density Polyethylene Waste for Synthesis of Carbon Nanotubes | 10.1007/s10891-021-02313-w |
2021-03-01 | Abstract — It is shown that the wear resistance of graphitized steel under abrasive action and dry sliding friction can be increased by heat treatment that forms an increased content of metastable residual austenite in the steel structure, which undergoes dynamic strain martensitic transformation (DSMT), the self-quenching effect under loading, (SQL). In order to obtain an optimal content of metastable retained austenite (36%) in the structure of graphitized steel along with tempered martensite and graphite, as well as to achieve the highest relative abrasive wear resistance (ε a = 4.8) and wear resistance in dry sliding friction (ε dsf = 2.8) than occurs after routine heat treatment (ε a = 3.5) and (ε dsf = 2), heating to 950°С is required before quenching. Isothermal quenching, including austenitization at 850°C, cooling in water to an isothermal temperature of 300°C, holding for 10 min at this temperature in a furnace, and a subsequent cooling in air led to a slight increase in the relative abrasive wear resistance (ε a = 3.8) as compared to the standard heat treatment (ε a = 3.5). This procedure provides a significantly higher relative wear resistance of graphitized steel under dry sliding friction (ε dsf = 3.6) than one could provide by routine quenching from a commonly used temperature (ε dsf = 2), or by quenching from an elevated temperature (ε dsf = 2.8) together with low-temperature tempering. The use of the proposed treatment procedures for graphitized steel should provide an increase in the durability of tools made of such a material and reduce the costs for purchasing it. | Increasing the Wear Resistance of Graphitized Steel by Obtaining Metastable Austenite in the Structure | 10.3103/S1068366621020070 |
2021-03-01 | Generation of value-added materials from waste product is in high demand for sustainable chemistry. In order to reduce the use of toxic chemicals in the synthesis of metal nanoparticles, alternative green methods are in demand. Herein, we report the synthesis of copper oxide nanoparticles from plant extract of Colocasia esculenta leaves which is thrown as waste after cultivation. The synthesized nanoparticle was characterized using UV, FT-IR, EDX, TEM, AAS, DLS, and XPS. The synthesized nanoparticles were used as heterogenous catalyst for carrying out the click reaction of azide and alkyne. The catalyst showed good catalytic activity for the synthesis of various 1,2,3-triazoles with very low catalyst loading (0.535 mol% of copper) giving excellent yield of various triazoles. The catalyst could be easily separated from the reaction medium and recycled several times without losing much catalytic activity. The catalyst showed good TON (177.6) and TOF (29.6 h −1 ) for the optimized reaction. Thus, the method has several advantages such as synthesis of the nanoparticle from cheap sources (plant extract of waste Colocasia esculenta leaves), use of the water as environmentally benign solvent for carrying out the click reaction, one-pot reaction, low catalyst loading, recyclability of catalyst, and high yield of 1,2,3-triazole products. | Green Biosynthesis of Copper Oxide Nanoparticles Using Waste Colocasia esculenta Leaves Extract and Their Application as Recyclable Catalyst Towards the Synthesis of 1,2,3-triazoles | 10.1007/s12668-021-00826-5 |
2021-03-01 | Biomass-derived carbon-attapulgite adsorbent was developed for organic pollutants removal. All the batch assays were performed to evaluate the effects of organic components, contact time, and initial concentration of organic pollutants on the adsorption performance of the as-prepared adsorbent. The samples were characterized via Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results demonstrated that the acid-treated carbon-attapulgite adsorbent (H-ATP/BC) showed a large specific surface area (237 m 2 g −1 ) and possessed abundant oxygen-containing functional groups and silicon-oxygen bonds (i.e., O-Si-O and O-Si), which provided more active sites and conduced to the adhesive of organic pollutants. Both physical adsorption and chemical adsorption were involved in the adsorption process, and competitive adsorption occurred when two or more target pollutants coexist. Especially, phenol and/or aniline with an aromatic ring were much more likely to adhere to the H-ATP/BC surface than pyridine, and the selectivity order of H-ATP/BC for these pollutants was phenol > aniline > pyridine. From the model fitting, it was observed that the adsorption data could be described well by a pseudo-second-order model and Freundlich isotherms. The theoretical maximum phenol, aniline, and pyridine adsorption capacities of the H-ATP/BC were 14.31 mg g −1 , 15.21 mg g −1 , and 20.74 mg g −1 , respectively. Comparison among the commercial adsorbents price also illustrated that H-ATP/BC could be a promising material for efficient treatment of organic pollutants. Graphical abstract | Promoting adsorption of organic pollutants via tailoring surface physicochemical properties of biomass-derived carbon-attapulgite | 10.1007/s11356-020-10974-y |
2021-03-01 | Abstract The first sediment N-isotope data on the Permian–Triassic boundary transition of the Verkhoyansk region are obtained. Together with the other published materials on other regions of eastern Russia allow us to distinguish a number of N-isotope intervals of various ranks in the Permian–Triassic of eastern Russia. In addition to the well-known method of reconstructing the redox conditions of the marine environment from N‑isotope data (in combination with data on elevated concentrations of redox-sensitive trace metals), the possibility of using N-isotope data also to determine the direction of temperature changes in the marine environment is substantiated. It is assumed that N-isotope signals are primarily a reflection of events associated with denitrification and N 2 fixation, the main processes of the global nitrogen biogeochemical cycle (NBC). Deviations in the direction of increasing δ 15 N values in the considered sections are associated with an increase in upwelling activity and the supply of cool deep waters enriched in the heavy N isotope to the shelf zone; the opposite deviations are associated with a slowdown or cessation of inflow of cool deep waters. The N-isotope data obtained, in combination with the published materials on O-isotope thermometry in the Tethyan Superrealm during the Permian and Triassic, indicate a very likely coincidence of the direction of temperature changes caused by both regional (upwelling) and global (climatic) events of that time. In this regard, the reconstructions of the marine environment that we conduct by the example of the Permian–Triassic sections of Northeast Asia (Verkhoyansk, Kolyma–Omolon, and South Primorye) seem to be appropriate, although they require additional confirmation on the material from other sections of the world. The problems associated with differences in the average δ 15 N values in the Permian–Triassic sections of different provinces of the Boreal Superrealm, as well as other superrealms, are considered. | Variations in Nitrogen Isotope Composition in Clay Deposits of the Permian–Triassic Boundary Beds in the Verkhoyansk Region (Northeast Asia) and Their Implication for Reconstruction of Marine Environments | 10.1134/S0869593821020076 |
2021-03-01 | Ultra high temperature zirconium carbide ceramic powder was prepared using a low cost technique using zirconium isopropoxide and phenolic resin. The effect of monomer feed ratio, heating rate and temperature on the nature and properties of the ceramics obtained were studied in detail. The samples were heat treated at two different temperatures using different heating rates and the ceramics obtained were characterised using XRD, SEM, TGA and particle size. The SEM images showed that the nature of particles obtained from both the systems is different. XRD confirmed complete ceramic conversion at 1650 °C whereas at 1600 °C, minor peaks for ZrO 2 were present. The crystallite size of both the samples was well below 35 nm. | Synthesis of Ultra High Temperature Ceramic Zirconium Carbide for Space Applications | 10.1007/s41403-020-00176-w |
2021-03-01 | The development of ceramic-polymer electrolyte with high mechanical and electrochemical properties is the key to address the safety issue of high-performance lithium batteries due to the use of flammable organic liquid electrolytes. In this work, we designed and synthesized a flexible low liquid leakage and high wettability ceramic-polymer electrolyte (CPE) based on poly(vinylidene fluoride) (PVDF)-poly(ethylene oxide) (PEO)-γ-Al 2 O 3 membrane with excellent mechanical and thermal stability. After being wetted by a very small amount of LiPF 6 -based liquid electrolyte, symmetrical Li, Li/LiFePO 4 (LFP), and LFP/Li 4 Ti 5 O 12 (LTO) cells with this PVDF/PEO-γ-Al 2 O 3 -LiPF 6 CPE displayed much better cycling stabilities than that of commercial Celgard 2320 separator with a sufficient amount of liquid electrolyte. The CPE requires only a small amount of liquid electrolyte to achieve the desired electrochemical performance of lithium batteries. Its low liquid leakage characteristic also enhances the safety of lithium batteries, with the potential to replace the commercial separators. | High safety and long-life lithium batteries with low leakage and high wettability ceramic-polymer electrolyte | 10.1007/s11581-020-03892-z |
2021-03-01 | Abstract X-ray amorphous ribbons of aluminum-based alloys doped with transition (Ni, Fe) and rare earth (La) metals in various ratios were obtained by melt spinning. The mechanical characteristics and fracture surfaces of the ribbons under conditions of uniaxial tension with speeds from 0.01 to 10 mm/min were studied. It was shown that, with an increase in the rate in all investigated alloys, the strength limit increases and low plasticity remains. Inhomogeneous deformation is realized by the initiation and spread of shear bands. The mixed fracture surface indicates a brittle-viscous fracture with a high ratio of the viscous component. A significant influence of the scale factor on the strength characteristics of the ribbons was confirmed. The tensile strength of the ribbons increases with rising iron content and decreasing nickel content when the influence of the scale factor is excluded. It is experimentally shown on ribbons with a low-melting tin coating that local heating in shear bands reaches the melting point of tin of 231.9°C. | Low-Temperature Deformation of Al–Ni–Fe–La System Amorphous Alloys | 10.1134/S2075113321020076 |
2021-03-01 | Objective The rapid accumulation of crude-oil based plastics in the environment is posing a fundamental threat to the future of mankind. The biodegradable and bio-based polyhydroxyalkanoates (PHAs) can replace conventional plastics, however, their current production costs are not competitive and therefore prohibiting PHAs from fulfilling their potential. Results Different low-quality animal by-products, which were separated by thermal hydrolysis into a fat-, fat/protein-emulsion- and mineral-fat-mixture- (material with high ash content) phase, were successfully screened as carbon sources for the production of PHA. Thereby, Ralstonia eutropha Re2058/pCB113 accumulated the short- and medium-chain-length copolymer poly(hydroxybutyrate- co -hydroxyhexanoate) [P(HB- co -HHx)]. Up to 90 wt% PHA per cell dry weight with HHx-contents of 12–26 mol% were produced in shake flask cultivations. Conclusion In future, the PHA production cost could be lowered by using the described animal by-product streams as feedstock. Graphical abstract | Low-quality animal by-product streams for the production of PHA-biopolymers: fats, fat/protein-emulsions and materials with high ash content as low-cost feedstocks | 10.1007/s10529-020-03065-y |
2021-03-01 | Abstract The effect of synthesis conditions and incorporation of heteroatoms on the structure and morphology of few-layer graphene nanoflakes is investigated using Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy. It is found that doping with nitrogen forms defects inside graphene layers, while incorporation of silicon in contrast results in their bending and the formation of interlayer defects. Increasing the synthesis temperature reduces the number of defects in the material via graphitization and increase in the number of layers. | Effect of Synthesis Conditions on Morphology, Structure, and Defectiveness of Few-Layer Graphene Nanoflakes | 10.1134/S0036024421030109 |
2021-03-01 | This study presents the results of designing a low-cost air sampler for multi-component analysis of PM 2.5 . We developed a multi-channel air sampling device using sonic venturi (critical nozzle) that supplies a constant airflow rate of 16.7 L/min. The constant flow rate is achieved with a backpressure ratio of 0.8 or less with a nozzle diameter of 1.375 mm. The sampler halves the cost of comparable devices and simplifies the hardware by replacing the flow meters with critical nozzles. For quantitative evaluation, we measured the coefficient of variation (CV) of each component simultaneously collected five samples at various particulate matter concentrations. This sampler can use different types of filters such as polytetrafluoroethylene and quartz fiber filter at the same time. Meteorological conditions such as ambient temperature, relative humidity and atmospheric pressure did not seem to affect much the flow rate of the sampler. The CV of multi sample analysis for TSP and PM 2.5 concentrations in all sampling periods were less than 10%. CV of multi sample analysis for most of the major inorganic elements being within the range of 15% or less shows that the precision is sufficient for reliable measurement. We believe that the low-cost multiple air sampler will be used world-widely, and it can contribute to many researchers in both developed and developing countries. | Development of A Low-cost Simultaneous Low Volume Air Sampler Controlled with Sonic Venturi | 10.5572/ajae.2020.072 |
2021-03-01 | Metalworking fluids used in industrial workshops may present a major threat to the health of workers who have been exposed to a high oil mist concentration over a long period of time. Therefore, monitoring the temporal and spatial distribution of particulate matter concentration has great practical significance for the control of oil mist. Traditional particle monitors are generally cumbersome, expensive, and difficult to maintain, which to some extent restricts their extensive use in workshops. Recent years have witnessed tremendous developments in the area of low-cost sensors, which are of great help in obtaining high-density pollution data. In this paper, we evaluate the performance of an inexpensive laser sensor (A4-CG) during long-term oil mist monitoring in a machine shop for the first time. With the use of Lora technology, we developed an online oil mist monitoring network to access real-time concentration, temperature, and humidity information from distributed monitors. According to the results, the sensor data correlated well with measurements by the reference instrument ( R 2 = 0.96), which means that the distributed sensor network can accurately detect the concentration level of oil mist in the workshop. In fact, most of the sensors demonstrated stable operation for up to half a year according to cluster analysis, while several sensors exhibited serious data drift. Furthermore, the results indicate that the peak oil mist concentration in most areas during production exceeded the value of 0.5 mg m −3 recommended by NIOSH, and it was found that appropriately lowering the relative humidity can make sampling more accurate, while lowering the temperature can reduce the oil mist concentration in the workshop. Thus, measures to control oil mist such as generation and distribution of pollution sources should be on the agenda. | Low-cost sensor system for monitoring the oil mist concentration in a workshop | 10.1007/s11356-020-11709-9 |
2021-03-01 | Globally, water bodies adjacent to mangroves are considered significant sources of atmospheric CO 2 . We directly measured the partial pressure of CO 2 in water [ p CO 2 (water)] and related biogeochemical parameters with high temporal resolution, covering both diel and tidal cycles, in the mangrove-surrounding waters around the northern Bay of Bengal during the post-monsoon season. Mean p CO 2 (water) was marginally oversaturated in two creeks (470 ± 162 µatm, mean ± SD) and undersaturated in the adjoining estuarine stations (387 ± 58 µatm) compared to atmospheric p CO 2 , and was considerably lower than the global average. We further estimated the p CO 2 (water) and buffering capacity of all possible sources of the mangrove-surrounding waters and concluded that their character as a CO 2 sink or weak source is due to the predominance of marine water from the Bay of Bengal with low p CO 2 and high buffering capacity. Marine water with high buffering capacity suppresses the effect of p CO 2 increase within the mangrove system and lowers the CO 2 evasion even in creek stations. The δ 13 C of dissolved inorganic carbon (DIC) in the mangrove-surrounding waters indicated that the DIC sources were a mixture of mangrove plants, pore-water, and groundwater, in addition to marine water. Finally, we showed that the CO 2 evasion rate from the estuaries of the Sundarbans is much lower than the recently estimated world average. Our results demonstrate that mangrove areas having such low emissions should be considered when up-scaling the global mangrove carbon budget from regional observations. | Low CO2 evasion rate from the mangrove-surrounding waters of the Sundarbans | 10.1007/s10533-021-00769-9 |
2021-03-01 | From sustainable chemistry and engineering perspectives, water and energy consumption are arguably the main issues in the textile industry. Thus, a silicone reverse emulsion dyeing system is developed to dye cellulosic textile with reactive dye. When the amount of dye is the same, the color depth of dyed cotton fiber is 13.82 and the fixation of dye is 87.76% in the silicone reverse emulsion dyeing system. In traditional water-based dyeing system, the color depth of dyed cotton fiber and the fixation of dye is only 9.31, 56.63% respectively. The silicone reverse emulsion dyeing technology does not consumes salts, but it can improve the dye fixation by 31.13%, and decreases the dye discharge by 72.41%. For the hydrolysis of bifunctional reactive dye, the main hydrolysis reaction is the individual hydrolysis of monochlorotriazine or vinyl sulfone at the prophase of hydrolysis. After 30 min, the additional β-hydroxyethyl sulfone and hydroxyl triazine dye are hydrolyzed to dihydroxyl dye. To confirm the hydrolytic reaction energy of dye in different dyeing system, the optimization of molecular structure, the hydrolysis reaction gap and the distribution of electron density on the dye were investigated using density functional theory. The hydrolytic reaction energy gap of bifunctional reactive dye is higher in silicone reverse emulsion dyeing system than that in traditional aqueous dyeing system, resulting the hydrolysis of dye is difficult in silicone oil emulsion dyeing system. The electron density is distributed almost entirely on the carbon–carbon double bond and triazine group in the HOMO of the dye, resulting in the LUMO of dyes can attacked by HOMO of hydroxyl anion. These successful investigations of the dyeing performance and the hydrolysis mechanism of dye explain that reactive dye can keep a long reactivity to fiber and effectively reduce the number of washing times, which greatly reduces the discharge of dyeing waste water. | Sustainable dyeing of cotton fabric with reactive dye in silicone oil emulsion for improving dye uptake and reducing wastewater | 10.1007/s10570-020-03673-x |
2021-03-01 | This paper describes the surface modification of glassy carbon (GC) electrodes with a bamboo-based renewable carbon (RC) before and after an acid functionalization procedure with a sulfonitric solution (1:3 HNO 3 /H 2 SO 4 ). The morphology and structural characterization indicate an increase of functional groups in the functionalized renewable carbon (RCF) surface. The enhanced electroanalytical properties of RC and RCF were evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in two different setups, in the presence of the redox couple ([Fe(CN) 6 ] 3−/4− ) and escitalopram (EST). The results revealed an enhancement for the electrochemical responses of both inorganic and organic compounds in the electrolyte. Therefore, the use of new carbon-based materials such as renewable carbon for development of electrochemical sensors brings a fresh approach to low-cost device development. | A functionalized renewable carbon-based surface for sensor development | 10.1007/s10008-020-04882-x |
2021-03-01 | Enteric viruses, such as human norovirus (NoV) and hepatitis A virus (HAV), are the major causes of foodborne illnesses worldwide. These viruses have low infectious dose, and may remain infectious for weeks in the environment and food. Limited information is available regarding viral survival and transmission in low-moisture foods (LMF). LMFs are generally considered as ready-to-eat products, which undergo no or minimal pathogen reduction steps. However, numerous foodborne viral outbreaks associated with LMFs have been reported in recent years. The objective of this study was to examine the survival of foodborne viruses in LMFs during 4-week storage at ambient temperature and to evaluate the efficacy of advanced oxidative process (AOP) treatment in the inactivation of these viruses. For this purpose, select LMFs such as pistachios, chocolate, and cereal were inoculated with HAV and the norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), then viral survival on these food matrices was measured over a four-week incubation at ambient temperature, by both plaque assay and droplet-digital RT-PCR (ddRT-PCR) using the modified ISO-15216 method as well as the magnetic bead assay for viral recovery. We observed an approximately 0.5 log reduction in viral genome copies, and 1 log reduction in viral infectivity for all three tested viruses following storage of select inoculated LMFs for 4 weeks. Therefore, the present study shows that the examined foodborne viruses can persist for a long time in LMFs. Next, we examined the inactivation efficacy of AOP treatment, which combines UV-C, ozone, and hydrogen peroxide vapor, and observed that while approximately 100% (4 log) inactivation can be achieved for FCV, and MNV in chocolate, the inactivation efficiency diminishes to approximately 90% (1 log) in pistachios and 70% (< 1 log) in cereal. AOP treatment could therefore be a good candidate for risk reduction of foodborne viruses from certain LMFs depending on the food matrix and surface of treatment. | Survival and Inactivation by Advanced Oxidative Process of Foodborne Viruses in Model Low-Moisture Foods | 10.1007/s12560-020-09457-7 |
2021-03-01 | Abstract An analysis of the literature on polyethylene terephthalate modification by low-temperature plasma treatment is presented. The use of modern instrumental methods (measurement of contact angles and calculations of surface energy and its components, X-ray photoelectron spectroscopy and FTIR spectroscopy, atomic force and scanning electron microscopy) for studying the properties of processed polymer samples is considered. The change in contact properties, chemical structure, and morphology of the modified surface of polyethylene terephthalate is shown. Data on studying hemocompatibility, antibacterial activity, and cell adhesion and proliferation after plasma treatment of polyethylene terephthalate are presented. | Modification of Polyethylene Terephthalate by Low-Temperature Plasma for Use in Medicine and Biology | 10.1134/S0018143921020065 |
2021-03-01 | Abstract The study investigated, for the first time with respect to Fischer–Tropsch synthesis of fuels, cobalt-containing catalytic systems based on SAPO-11 molecular sieves with differing secondary porous structure characteristics. Various methods, such as XRD, low-temperature nitrogen adsorption/desorption, SEM, TEM, H 2 -TPD, and NH 3 -TPD, were used to characterize the prepared catalysts, which were subsequently examined in hydrocarbon synthesis at 2.0 MPa, 240°C, and gas WHSV = 1000 h –1 . The study demonstrated good prospects for micro/mesoporous-structured SAPO-11 as an acid catalyst component for fuel production. | Bifunctional Cobalt-Containing Catalytic Systems Based on
SAPO-11 Molecular Sieves in Fischer–Tropsch Synthesis of Fuels | 10.1134/S0965544121030063 |
2021-03-01 | Abstract A study of the effect of a seasonal decrease in ambient temperature on the composition of free amino acids and ninhydrin-positive secondary metabolites in gastrocnemius muscles of the frog Rana temporaria revealed that at the onset of winter anabiosis, as compared to the summer season, the alanine pool increased from 2.43 to 6.10 µmol/g w.w., and the 3-methylhistidine pool rose from 1.52 to 2.80 µmol/g w.w. For the first time, muscles of poikilothermic animals (namely, frogs) were found to contain cysteic acid and phosphoethanolamine, the level of which increased by the onset of hibernation, particularly for cysteic acid (from 0.91 to 2.15 µmol/g w.w.). The taurine level proved to be far lower compared to animals both of lower and higher phylogenetic ranks, but by the onset of hibernation it increased almost threefold. Presumably, the accumulation of the above metabolites relates to their protective role at temperatures that are extremely low for the survival of R. temporaria. | Low-Temperature Adaptation of the Rana temporaria Gastrocnemius Muscle
at the Onset of Anabiosis | 10.1134/S0022093021020071 |
2021-03-01 | Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density. This prototype was an active attempt and early exploration for future APPLE–Knot undulator, which will be used at high energy photon source (HEPS). Materials and methods There are several challenges to develop a cryogenic delta undulator, such as the complicated structure, the influence of large magnetic force, and the magnetic measurement difficulty due to the very small gap. In this paper, the mechanical design for overcoming these difficulties will be presented in detail. Conclusion A special hall measuring system is developed, and the preliminary results agree with the theoretical results. This undulator prototype will provide valuable experience for angle magnetization technology, intricate magnetic attraction structure design, and magnetic field measurement under closed small space. | Mechanical design of a cryogenic Delta–Knot undulator for high energy photon source | 10.1007/s41605-020-00228-3 |
2021-03-01 | Urban gardening is growing as an increasingly therapeutic, social, mental, environmental, and economical alternative to improve the quality of life. One of the options to enhance this activity is the use of mulches. There are several reports on the use of cellulose-based mulches in rural areas. This work is the first successful study on the use of nanocellulose mulches for small-scale urban food production based on bacterial nanocellulose (BNC) pellicules constituted by nanoribbons. In this case, the pellicules were produced by bacteria isolated from the Colombian species Komagataeibacter medellinensis (previously referred to as Gluconacetobacter medellinensis sp. Nov., a new acid-resistant strain that can grow at a pH as low as 3.5) under simple static conditions. A cheap substrate, such as ripened fruit not suitable for human consumption, was used to produce the BNC mulches. The obtained BNC mulches are cheap and environmentally friendly than plastic mulch based on polyethylene. The effectiveness of BNC pellicule mulches was evaluated during the growth of one type of onion plant under urban garden conditions and was compared with an uncovered system and a commercial polyethylene mulch. Progressive degradation of BNC mulches took place during plant growth, indicating the biodegradability of BNC mulches, and thus, the onion plants exhibited healthy physiological development. The results suggest that BNC mulches are environmentally friendly and easy to use for the protection of small-scale food production in urban areas during short plant-growing periods. | Bacterial Nanocellulose Mulch as a Potential Greener Alternative for Urban Gardening in the Small-Scale Food Production of Onion Plants | 10.1007/s40003-020-00479-y |
2021-03-01 | We develop a complex technology of fabrication of oil-and-gas pipes with elevated corrosion resistance, including the procedure of controlled forge-rolling of pipe blanks of 06X1-Y steel with regulated contents of chemical elements and the procedure of heat treatment, namely, hardening with double short-term high tempering at temperatures maximally close to the temperature of the α → γ phase transformation of steel. It is shown that pipes made of this steel have a fine-grained ferrite-pearlitic structure with high (up to 23%) contents of special α –α and α –γ low-energy boundaries and elevated corrosion resistance observed in the course of testing of the specimens in chloride and model chloride-acetate solutions. Moreover, these pipes are less susceptible to hydrogenation under the conditions of cathode polarization in 1 N H 2 SO 4 + 1.5 g/liter CS(NH 2 ) 2 and exhibit higher resistances both to sulfide stress corrosion cracking (SSCC) and to hydrogen-induced cracking than the pipes made of 20 steel. It is shown that the procedure of heat treatment performed according to the developed technology increases the SSCC resistance (σ gr ≥ 0.85 σ 0.2 ) and improves the mechanical properties of the pipes up to the strength grade X56 according to the standard of the American Petroleum Institute API 5L. | Methods for the Improvement of Corrosion Resistance of Low-Alloy Steel Pipes for the Oil-And-Gas Extraction Industry | 10.1007/s11003-021-00483-9 |
2021-03-01 | The methods of transmission and scanning electron microscopy are used to study the evolution of the structure of a welded joint of steels 32G2 and 40KhN in the thermomechanically affected zone (TAZ) under rotary friction welding (RFW). EBSD analysis is used to certify the microstructure in different parts of the TAZ and to calculate the densities of the low- and high-angle boundaries. It is shown that complex processes of dynamic recrystallization combining several mechanisms develop in all these regions of the TAZ. Typical differences in the structures of the mobile (steel 40KhN) and immobile (steel 32G2) parts of the billets are described. | Evolution of Microstructure in the Thermomechanically Affected Zone of Welded Joints of Medium-Carbon Steels in the Process of Rotary Friction Welding | 10.1007/s11041-021-00630-8 |
2021-03-01 | The South Asian summer monsoon brings copious rain to agriculture-dependent country India and bulk of the precipitation in central India is attributed to monsoon low pressure systems (LPS). Large uncertainty exists in the statistics of LPS during the historical period and in future projections. In this study, we have developed an LPS tracking approach which considers geopotential height anomaly and relative vorticity thresholds. The approach is validated by comparing characteristics of LPS from our tracking scheme with those from previous studies. Our analysis indicates around 14 LPS per year (over 68 LPS-days). 60–70% of monsoon rainfall in north, east and central India is found to be associated with LPS (location is within 1000 km radii of LPS). Over the central Indian region, around 82% of extreme precipitation events occur during LPS days, out of which 47% are on depression and deep depression days and 78% is associated with LPS. 15–25% of monsoon precipitation in central and East Indian states is in the form of extreme precipitation associated with LPS. At many locations in central India, very heavy precipitation (≥ 124.5 mm/day) due to LPS is estimated to have a return period less than 5 years. Further, our analysis shows that the intensity of extreme precipitation is larger by 50% (95th percentile precipitation) to 100% (99th percentile) when the extreme is associated with LPS. Our analysis of extreme precipitation related to LPS has the potential to provide valuable information for flood risk assessment during monsoon season in central India. | Characteristics of the monsoon low pressure systems in the Indian subcontinent and the associated extreme precipitation events | 10.1007/s00382-020-05562-2 |
2021-03-01 | Numerous studies have addressed the utilization of polyimide (PI) and silica for improving the properties of hybrid composites. However, the applicability of polyhedral oligomeric silsesquioxanes (POSSs) has not been elucidated. Herein, inorganic nanoparticles containing poly(amic acid)s (PAAs) were synthesized; further, glass fibers (GFs) were impregnated with PAA solutions to obtain PAA prepregs. PI-based fiber-reinforced composites were manufactured with the prepregs by using the hand lay-up technique. The morphology and the thermal, mechanical, and dielectric properties of the composites with inorganic nanoparticles were analyzed to investigate the effects of inorganic additives. The addition of inorganic particles were observed to primarily improve the properties of the PI-based fiber-reinforced composites as compared to those of the neat PI composites. While this improvement was limited in the case of the addition of POSSs owing to the aggregation and a poor interaction with the PI matrix, silica-containing composites exhibited superior thermal, mechanical, and particularly dielectric properties as compared to those of the composites containing POSSs; this was because of the increase in the dispersion of silica nanoparticles that was caused by a silane coupling agent (SCA). The results obtained in this study can be utilized for applications pertaining to the design of PI composites with high mechanical strengths, enhanced thermal stabilities, and low dielectric constants. | Fabrication and Properties of Glass Fiber-Reinforced Composites Using Polyimide Prepregs with Inorganic Nanofillers | 10.1007/s12221-021-0148-1 |
2021-03-01 | In this study, seven rainfall-runoff models were applied to model daily River Kafu flows from 1952 to 1981. Among others, models from the rainfall-runoff library of the eWater toolkit were applied. Optimal parameters of each model were obtained based on an automatic calibration strategy. Averaging in terms of simple arithmetic mean, hereinafter taken as the multi-model ensemble (MME), was performed to independently and identically distributed events separately extracted from the outputs of the individual models. How well the MME captured variation and frequency of observed hydrological extremes was assessed. Models performed better for high flows than low flows. Absolute model average biases on quantiles with return periods from 1 to 30 years were over the ranges 5.5–83.6% and 11.6–57.7% for high flows and low flows, respectively. It is envisaged that making model structures flexible and performing calibration with objective functions constrained to extreme events can enhance simultaneous capturing of high flows and low flows. The amount of variance in annual maxima series that could be explained by the multi-model ensemble was 73.4% and ranged from 35.1 to 82.5% for the individual models. This made the multi-model ensemble better than outputs from six of the seven models. For the annual minima flows, the multi-model ensemble yielded the smallest root mean squared error but the third largest coefficient of determination. Notably, the suitability of the multi-model ensemble in capturing the hydrological extremes depends on the selected goodness-of-fit measure, approach for combination of model outputs, number of models considered and length of data used. | Suitability of averaged outputs from multiple rainfall-runoff models for hydrological extremes: a case of River Kafu catchment in East Africa | 10.1007/s42108-020-00075-4 |
2021-03-01 | In the automotive industry, it is essential to reduce the weight of the car body to improve fuel efficiency and reduce CO 2 gas emissions. As such, the application of advanced high-strength steels is rapidly increasing. However, in the case of gas metal arc (GMA) welding of advanced high-strength steels (AHSS), slag particles are observed to form on the weld surface resulting in poor corrosion resistance. The presence of slag particles on the weld also affects mechanical performance. This paper focuses on the degradation of corrosion resistance due to these slag particles. Current methods to decrease slag islands are costly as they attempt (1) to better protect the weld pool by decreasing the content of oxygen-containing ingredients or increasing argon in the shielding gas and (2) to mechanically clean the weld surface using processes such as shot blasting after gas metal arc welding (GMAW). In this study, the amount of slag was reduced by adjusting the chemical composition of welding consumables. Silicon was decreased to minimize silica/silicate formation, and sulfur was adjusted to affect the surface tension balance of the molten pool. Slag particles were observed to flow along the welding direction to solidify into a large particle in the weld crater that could be removed easily. In a separate consumable, Si and Mn contents were adjusted to form Mn 3 O 4 and SiO 2 slag. The use of these two welding consumables reduced the amount of slags, which improved the corrosion resistance. It is not the intent of this paper to compare the performance of these two experimental consumables, however. | Effect of chemical composition of welding consumable on slag formation and corrosion resistance | 10.1007/s40194-020-01059-y |
2021-03-01 | Abstract Small angle neutron scattering was applied to steel produced by rolling with shear (RS) technology and compared to samples produced by standard technology (ST). Based on small angle neutron scattering measurements the morphology of the grains and pores of RS steels were compared to those of the ST steels. The scattering in small scattering vector region showed anisotropy, attributed to the elongation of the pores; the pearlite lamellae distances along and perpendicular to the rolling directions differed by a factor of 1.5. The results of the Small angle neutron scattering measurements were in accordance with the electrical characteristics of the specimens. They showed smaller and less anisotropic average sizes of the cracks and nanopores for the RS samples than for the ST rods. This confirms the dynamic healing of the nanosized defects during the cold drawing of the RS rods. This fundamental result shows that during severe plastic deformation a cyclic process of nucleation and healing of the nanovoids took place. However, during the standard deformation process only nucleation of the nanovoids is present. Graphic abstract | Small Angle Neutron Scattering Study of Nanoscale Structure of Low-Carbon Steel After Rolling with Shear Followed by Cold Drawing | 10.1007/s12540-020-00766-x |
2021-03-01 | The oxidation of oxygen ions and the generation of an anode effect at a low oxygen content of 150 mg/kg were discussed in this paper. Cyclic voltammetry and square-wave voltammetry tests were conducted to explore the anodic processes of LiF–NdF 3 melt after a lengthy period of pre-electrolysis purification at 1000°C (during which the oxygen content reduced from 413 to 150 mg/kg). The oxidation process of oxygen ions was found to have two stages: oxidation product adsorption and CO/CO 2 gas evolution. The adsorption stage was controlled by diffusion, whereas the gas evolution was controlled by the electrochemical reaction. In comparison with oxygen content of 413 mg/kg, the decrease in the amplitude of the current at low oxygen content of 150 mg/kg was much gentler during the forward scanning process when the anode effect occurred. Fluorine-ion oxidation peaks that occurred at about 4.2 V vs. Li/Li+ could be clearly observed in the reverse scanning processes, in which fluorine ions were oxidized and perfluorocarbons were produced, which resulted in an anode effect. | Electrochemical investigation of the anode processes in LiF–NdF3 melt with low oxygen content | 10.1007/s12613-020-2010-7 |
2021-03-01 | Aluminium (Al) toxicity in acid soils inhibits root elongation and development causing reduced water and nutrient uptake by the root system, which ultimately reduces the crop yield. This study established a high throughput hydroponics screening method and identified Al toxicity tolerant accessions from a set of putative acid tolerant lentil accessions. Four-day old lentil seedlings were screened at 5 µM Al (pH 4.5) for three days in hydroponics. Measured pre and post treatment root length was used to calculate the change in root length (ΔRL) and relative root growth (RRG%). A subset of 15 selected accessions were used for acid soil Al screening, and histochemical and biochemical analyses. Al treatment significantly reduced the ΔRL with an average of 32.3% reduction observed compared to the control. Approximately 1/4 of the focused identification of germplasm strategy accessions showed higher RRG% than the known tolerant line ILL6002 which has the RRG% of 37.9. Very tolerant accessions with RRG% of > 52% were observed in 5.4% of the total accessions. A selection index calculated based on all root traits in acid soil screening was highest in AGG70137 (636.7) whereas it was lowest in Precoz (76.3). All histochemical and biochemical analyses supported the hydroponic results as Northfield, AGG70137, AGG70561 and AGG70281 showed consistent good performance. The identified new sources of Al tolerant lentil germplasm can be used to breed new Al toxicity tolerant lentil varieties. The established high throughput hydroponic method can be routinely used for screening lentil breeding populations for Al toxicity tolerance. Future recommendations could include evaluation of the yield potential of the selected subset of accessions under acid soil field conditions, and the screening of a wider range of landrace accessions originating from areas with Al toxic acid soils. | New sources of lentil germplasm for aluminium toxicity tolerance identified by high throughput hydroponic screening | 10.1007/s12298-021-00954-y |
2021-03-01 | Industrial Internet of Things (IIoT) is performed based on the multiple sourced data collection, communication, management and analysis from the industrial environment. The data can be generated at every point in the manufacturing production process by real-time monitoring, connection and interaction in the industrial field through various data sensing devices, which creates a big data environment for the industry. To collect, transfer, store and analyse such a big data efficiently and economically, several challenges have imposed to the conventional big data solution, such as high unreliable latency, massive energy consumption, and inadequate security. In order to address these issues, edge computing, as an emerging technique, has been researched and developed in different industries. This paper aims to propose a novel framework for the intelligent IIoT, named Industrial Internet of Learning (IIoL). It is built using an industrial wireless communication network called Low-power wide-area network (LPWAN). By applying edge computing technologies in the LPWAN, the high-intensity computing load is distributed to edge sides, which integrates the computing resource of edge devices to lighten the computational complexity in the central. It cannot only reduce the energy consumption of processing and storing big data but also low the risk of cyber-attacks. Additionally, in the proposed framework, the information and knowledge are discovered and generated from different parts of the system, including smart sensors, smart gateways and cloud. Under this framework, a pervasive knowledge network can be established to improve all the devices in the system. Finally, the proposed concept and framework were validated by two real industrial cases, which were the health prognosis and management of a water plant and asset monitoring and management of an automobile factory. | Industrial Internet of Learning (IIoL): IIoT based pervasive knowledge network for LPWAN—concept, framework and case studies | 10.1007/s42486-020-00050-2 |
2021-03-01 | Culture media is classified into several categories depending on their composition or application. Bacterial cellulose (BC) is a promising biomaterial with desirable properties for industrial and commercial applications. Based on that, its production was explored in several works on the modulation of the culture media. This review provides an overview of the advantages and limitations of undefined and defined media for BC production. The majority of these reported researches are based in complex media through modification of carbon and nitrogen sources. Some of them focused on the addition of non-conventional components to improve BC yield and reduce the production cost. However, the exact composition of these media cannot be determined, hindering the process reproducibility. Alternatively, chemically and minimal defined media, that are required in biochemical, physiological and genetic studies, due its exact amount of nutrients, are potential alternatives as BC culture media. The modulation of different types of culture media will determine the costs, yield and properties of BC. Graphic abstract | A review of culture media for bacterial cellulose production: complex, chemically defined and minimal media modulations | 10.1007/s10570-021-03754-5 |
2021-03-01 | The transformations of the electron energy distribution (EEDF), their concentration, and plasma space potential along the discharge gap between the hollow rectangular cathode and the mesh anode were experimentally studied. The discharge was 3 cm long, with a cross-section of 10 cm 2 . A new version of measurements with several single probes with the formation of current-voltage characteristics (IVC) in the probe circuit was proposed with the simultaneous application of voltages in the form of a combination of periodic and noise signals. The proportions of the signals were varied for different sections of the current-voltage characteristics. Measurements along the central axis of the discharge were taken. The dynamic range of the EEDF was not less than 4 orders of magnitude at the electron concentrations of 2–13 × 10 10 cm −3 , which exceeds the best known achievements. Measurements for discharge in helium at reduced pressures of 1–1.2 mbar and currents of 150–400 mA showed that the EEDFs differ from Maxwell ones, with an excess of fast electrons in the region of 10–20 eV at medium energies 4–6 eV. The fraction of fast electrons decreased in regions closer to the anode, which is associated with the nonlocality of the mechanism of the spectrum formation of free electrons. EEDFs transformations led to the space dependence of electron drift velocities on the plasma area. The dependence of the voltage drop across the cathode on the gas pressure and discharge current was noted. | Spatial Variations of Plasma Parameters in a Hollow Cathode Discharge | 10.1007/s11090-020-10137-4 |
2021-03-01 | The use of light-emitting diodes (LEDs) is increasingly used in fishing gears and its application is known to trigger negative or positive phototaxis (i.e., swimming away or toward the light source, respectively) for some marine species. However, our understanding of how artificial light influences behavior is poorly understood for many species and most studies can be characterized as trial and error experiments. In this study, we tested whether exposure to white LED light could initiate a phototactic response in Antarctic krill ( Euphausia superba ). Trawl-caught krill were used in a controlled artificial light exposure experiment conducted onboard a vessel in the Southern Ocean. The experiment was conducted in chambers with dark and light zones in which krill could move freely. Results showed that krill displayed a significant positive phototaxis. Understanding this behavioral response is relevant to development of krill fishing technology to improve scientific sampling gear, improve harvest efficiency, and reduce potential unwanted bycatch. | Antarctic krill (Euphausia superba) exhibit positive phototaxis to white LED light | 10.1007/s00300-021-02814-7 |
2021-03-01 | With the fast development of electronic technique, abundant microwave radiation and interference affect the human’s health deeply. Here, a novel low-frequency microwave absorbent of TiO 2 /ZnFe 2 O 4 /ZnTiO 3 nanocomposite was prepared via a combinative route of sol–gel, solvothermal and calcination. The electromagnetic wave-absorbing properties of this ternary nanocomposite are closely related to the pre-treated concentration of TiO 2 with nitric acid. The suitable concentration can promote the final absorption performance due to the increasing surface groups and defects for enhanced dipole polarization. The interface polarization between anatase and rutile TiO 2 also contributes a lot to the absorption effect. Additionally, the natural resonance, eddy current, multiple scattering and good impedance match play a significant effect as well. Thus, the excellent microwave-absorbing ability of as-prepared composite generates from the synergy effectiveness of magnetic and dielectric losses. The optimal reflection loss reaches −45.3 dB at 1.19 GHz with EAB of 0.82 ~ 1.67 GHz for 3.5 mm, and the widest efficient absorbing bandwidth achieves 1.5 GHz at only 1.5 mm. The investigation reported here provides a novel route to adjust the microwave absorption capability of TiO 2 -based MAMs in low-frequency band. | Effect of nitric acid treatment on the final low-frequency microwave absorption performance of TiO2/ZnFe2O4/ZnTiO3 nanocomposite | 10.1007/s13204-020-01639-w |
2021-03-01 | Mechanical properties as well as crack resistance and stress corrosion cracking (SCC) resistance parameters of ultralow-carbon martensite steels (ULMS) type 05H2G2B and HSLA pipe steel 10G2FB with a different structures depending on processing are investigated. It is shown that despite a higher strength level, SCC resistance of ULMS steel is 25–30% higher than for HSLA steel with ferrite-perlite structure and close to that for this steel subjected to quenching and tempering. | Effect of Structural State on Tendency Towards Stress Corrosion Cracking of Ultralow-Carbon Martensitic and Low-Alloy Pipe Steels | 10.1007/s11015-021-01113-0 |
2021-03-01 | Masson pine ( Pinus massoniana Lamb.) is an economically important conifer tree that can be widely used for timber, pulp, and resin production. However, the phosphate (Pi) deficiency in tropical and subtropical forest soils poses severe challenges for the productivity of masson pine. WRKY transcription factors (TFs) have been proven to play important roles in plant responses to biotic and abiotic stresses, including low Pi stress; however, little is known about their roles in masson pine. To understand the roles of P. massoniana WRKY (PmWRKY) in low Pi stress, 25 putative WRKY TFs with complete WRKY domain from transcriptome sequencing data were identified. Based on their conserved domains and zinc-finger motif, the P. massoniana WRKY were divided into three groups. Structural feature analysis shows that PmWRKY proteins contain WRKYGQK/GKK/GRK domains and a C 2 H 2 /C 2 HC-type zinc-finger structure. To putatively identify the function of PmWRKY members involved in low Pi stress, transcriptional profiles of 17 PmWRKYs in masson pine under different Pi stresses were systematically established using real-time quantitative RT-PCR analysis. Analysis demonstrates that the candidate PmWRKYs were involved in responses to Pi starvation—for example, PmWRKY11 , 12 , and 13 were upregulated both in P 1 (Phosphorus content of 0.01 mM) and P 2 (Phosphorus content of 0.06 mM) stresses. The available evidence conclusively sheds light on protein structures, evolutionary relationships, and expression patterns of WRKYs in response to low Pi stress of masson pine, which facilitates further functional identification and molecular breeding for the enhancement of low-phosphorous tolerance in this species. | Transcriptome-Wide Identification and Expression Profiles of Masson Pine WRKY Transcription Factors in Response to Low Phosphorus Stress | 10.1007/s11105-020-01222-1 |
2021-03-01 | This article focuses on ceramic technology at Tell el-Iswid dating to the second half of the fourth millennium BC—Buto IIIa and Naqada III(A2)-B periods. The study investigates the crucial transitional period during the formation of the Egyptian State. It identifies four ceramic technical traditions and examines their respective evolution and interaction. It provides new data on the mechanisms underlying the homogenization of the material culture that preceded and accompanied the unification of Egypt. The results show increasing contact between the Delta and the Nile Valley during Buto IIIa, and confirm Naqadan potters’ presence in the Delta from at least the Naqada IIIA2 period. At this time, specialized ateliers emerged in the Delta region using a Middle/Upper Egypt’s chaîne opératoire for pottery manufacture. Nevertheless, the Lower Egyptian ceramic technical tradition persisted in the domestic sphere. Cet article porte sur la technologie des assemblages céramiques de Tell el-Iswid datant de la deuxième moitié du quatrième millénaire BC--Buto IIIa et Naqada III(A2)-B. En cela, il s’intéresse à une période de formation de la civilisation égyptienne cruciale. L’étude identifie quatre traditions techniques et analyse leurs interactions et leur évolution respective. Ce faisant, elle apporte de nouvelles données sur les mécanismes responsables de l’homogénéisation de la culture matérielle qui précède et accompagne l’unification politique en Egypte. Les résultats mettent en évidence les contacts croissants entre le delta et la vallée du Nil durant la période Buto IIIa et confirment la présence de potiers naqadiens dans le delta au moins à partir de Naqada IIIA2, comme en témoigne l’apparition dans cette région d’ateliers spécialisés qui fabriquent la céramique en suivant une chaîne opératoire exogène. A côté de cette nouvelle production spécialisée locale, on enregistre la persistance de la tradition des Cultures de Basse-Egypte (CBE) dans la sphère domestique. | The Evolution of Lower Egyptian Culture During the Formative Stages of the Egyptian State at Tell el-Iswid: The Contribution of Ceramic Technology | 10.1007/s10437-020-09421-7 |
2021-03-01 | It is critical to specify a signal that directly drives the transition that occurs between cell states. However, such inferences are often confounded by indirect intercellular communications or secondary transcriptomic changes due to primary transcription factors. Although FGF is known for its importance during mesoderm-to-endothelium differentiation, its specific role and signaling mechanisms are still unclear due to the confounding factors referenced above. Here, we attempted to minimize the secondary artifacts by manipulating FGF and its downstream mediators with a short incubation time before sampling and protein-synthesis blockage in a low-density angioblastic/endothelial differentiation system. In less than 8 h, FGF started the conversion of KDR low /PDGFRA low nascent mesoderm into KDR high /PDGFRA low angioblasts, and the priming by FGF was necessary to endow endothelial formation 72 h later. Further, the angioblastic conversion was mediated by the FGFR1/BRAF/MEK/ERK pathway in mesodermal cells. Finally, two transcription factors, ETV2 and LMO2, were the early direct functional responders downstream of the FGF pathway, and ETV2 alone was enough to complement the absence of FGF. FGF’s selective role in mediating the first-step, angioblastic conversion from mesoderm-to-endothelium thus allows for refined control over acquiring and manipulating angioblasts. The noise-minimized differentiation/analysis platform presented here is well-suited for studies on the signaling switches of other mesodermal-lineage fates as well. | FGF primes angioblast formation by inducing ETV2 and LMO2 via FGFR1/BRAF/MEK/ERK | 10.1007/s00018-020-03630-8 |
2021-03-01 | Abstract There is an increasing public awareness about the danger of dietary sugars with respect to their caloric contribution to the diet and the rise of overweight throughout the world. Therefore, low-calorie sugar substitutes are of high interest to replace sugar in foods and beverages. A promising alternative to natural sugars and artificial sweeteners is the fructose derivative 5-keto-D-fructose (5-KF), which is produced by several Gluconobacter species. A prerequisite before 5-KF can be used as a sweetener is to test whether the compound is degradable by microorganisms and whether it is metabolized by the human microbiota. We identified different environmental bacteria ( Tatumella morbirosei , Gluconobacter japonicus LMG 26773, Gluconobacter japonicus LMG 1281, and Clostridium pasteurianum ) that were able to grow with 5-KF as a substrate. Furthermore, Gluconobacter oxydans 621H could use 5-KF as a carbon and energy source in the stationary growth phase. The enzymes involved in the utilization of 5-KF were heterologously overproduced in Escherichia coli , purified and characterized. The enzymes were referred to as 5-KF reductases and belong to three unrelated enzymatic classes with highly different amino acid sequences, activities, and structural properties. Furthermore, we could show that 15 members of the most common and abundant intestinal bacteria cannot degrade 5-KF, indicating that this sugar derivative is not a suitable growth substrate for prokaryotes in the human intestine. Key points • Some environmental bacteria are able to use 5-KF as an energy and carbon source. • Four 5-KF reductases were identified, belonging to three different protein families. • Many gut bacteria cannot degrade 5-KF. | Degradation of the low-calorie sugar substitute 5-ketofructose by different bacteria | 10.1007/s00253-021-11168-3 |
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