Search

Inspired by mussel heuristic chemistry, a novel method for improving surface wettability and adhesion of carbon fibers with epoxy resins was proposed by codepositing gallic acid and polyethylene imine on the carbon fiber surfaces in a convenient operation. The results of scanning electron microscopy, infrared, Raman and X-ray photoelectron spectra revealed that gallic acid and polyethylene imine could undergo Michael addition or Schiff base reaction and codeposit on the carbon fiber surfaces successfully. The gallic acid-polyethylene imine codeposited carbon fibers were used to fabricate epoxy matrix composites. The results of mechanical tests showed that interlaminar shear strength, flexural modulus and strength of the gallic acid-polyethylene imine codeposited carbon fiber composite were increased by 27, 38, and 27% respectively, compared with those of the untreated carbon fiber composite. The conclusion can be drawn that the gallic acid-polyethylene imine codeposition is an effective method for improving interfacial properties of carbon fiber reinforced epoxy resin matrix composites. [ABSTRACT FROM AUTHOR]

NbC ceramic surface-reinforced steel matrix composites were prepared by an in-situ reaction method at different temperatures (1,050 °C, 1,100 °C and 1,150 °C) for different times (1 h, 2 h and 3 h). The phase constitution, microstructure and fracture morphology of NbC ceramic surface-reinforced steel matrix composites were analyzed by XRD, SEM and EDS, and the effects of the in-situ reaction temperature and time on the mechanical properties were systematically studied. The results indicate that the NbC reinforcement layer is formed through the reaction between Nb atoms and carbon atoms diffused from the steel matrix to the Nb plate. The thickness of this reinforcement layer increases as the reaction time prolongs. Additionally, an increase in reaction temperature results in a thicker reinforcement layer, although the rate of increase gradually decreases. The relationship among the thickness of the NbC reinforcement layer, the reaction time and temperature was established by data fitting. The optimal tensile performance is achieved at 1,100 °C for 1 h, with a tensile strength of 228 MPa. It is also found that the defects between the reinforcement layer and the steel matrix are related to reaction temperature. At 1,100 °C, these defects are minimal. Fracture mostly occurs in the NbC reinforced layer of the composites, and the fracture mode is characterized by typical intergranular brittle fracture. [ABSTRACT FROM AUTHOR]

There is still some controversy about the relationship between lipids and venous thrombosis (VTE). A bidirectional Mendelian randomization (MR) study was conducted to clarify the causal relationship between three classical lipids (low-density lipoprotein (LDL), high-density lipoprotein (HDL) and triglycerides (TGs)) and venous thromboembolism (VTE) (deep venous thrombosis (DVT) and pulmonary embolism (PE)). Three classical lipids and VTE were analysed by bidirectional Mendelian randomization (MR). We used the random effect inverse variance weighted (IVW) model as the main analysis model and the weighted median method, simple mode method, weighted mode method and MR–Egger methods as supplementary methods. The leave-one-out test was used to determine the influence of outliers. The heterogeneity was calculated by using Cochran Q statistics in the MR–Egger and IVW methods. The intercept term in the MR‒Egger regression was used to indicate whether horizontal pleiotropy affected the results of the MR analysis. In addition, MR-PRESSO identified outlier single-nucleotide polymorphisms (SNPs) and obtained a stable result by removing outlier SNPs and then performing MR analysis. When we used three classical lipids (LDL, HDL and TGs) as exposure variables, no causal relationship between them and VTE (DVT and PE) was found. In addition, we did not find significant causal effects of VTE on the three classical lipids in reverse MR analysis. There is no significant causal relationship between three classical lipids (LDL, HDL and TGs) and VTE (DVT and PE) from a genetic point of view. [ABSTRACT FROM AUTHOR]

Chemical pollutants present a substantial threat to the survival of the green turtle (Chelonia mydas). In this study, the concentrations of 12 trace elements (TEs) in seawater, sediments, and green turtle forage and eggshells from the Xisha Islands in the South China Sea, along with their patterns of transfer and accumulation, were identified. The results revealed that the median TE concentrations in seawater and sediments were lower than the first-grade limit values of the national standard in China, indicating a low ecological risk. The concentrations (μg·g−1) of TEs in forage ranged from 0.05–0.69, 3.43–14.4, 157–2391, 27.9–124, 2.05–9.39, 0.30–9.78, 2.01–80.50, 0.18–5.76, 0.06–0.98, 2.00–18.4, 0.02–0.24, and 0.01–0.09 for Cr, Mn, Sr, Fe, Ni, Cu, Zn, Se, Cd, As, Pb, and Hg, respectively. Seawater, sediments, turtle forage, and eggshells exhibited different TE profiles, which were driven by Hg, Sr, Cr, and Pb in seawater and sediments; Fe and Ni in sediments; Cd and As in forage; and Zn, Se, and Cu in eggshells. The contents of Cu, Zn, and Se increased slightly with trophic level, indicating that they were transferred through dietary pathways. Although Cd and As appeared to bioaccumulate in green turtle forage, it was not transferred to their eggshells, which may be related to the excretion and metabolism process in the mother's body. Thus, eggshells may be a poor bioindicator for the exposure of female green turtles to these toxic elements. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxias (SCAs) are a large group of hereditary neurodegenerative diseases characterized by ataxia and dysarthria. Due to high clinical and genetic heterogeneity, many SCA families are undiagnosed. Herein, using linkage analysis, WES, and RP-PCR, we identified the largest SCA36 pedigree in Asia. This pedigree showed some distinct clinical characteristics. Cognitive impairment and gaze palsy are common and severe in SCA36 patients, especially long-course patients. Although no patients complained of hearing loss, most of them presented with hearing impairment in objective auxiliary examination. Voxel-based morphometry (VBM) demonstrated a reduction of volumes in cerebellum, brainstem, and thalamus (corrected P < 0.05). Reduced volumes in cerebellum were also found in presymptomatic carriers. Resting-state functional MRI (R-fMRI) found reduced ReHo values in left cerebellar posterior lobule (corrected P < 0.05). Diffusion tensor imaging (DTI) demonstrated a reduction of FA values in cerebellum, midbrain, superior and inferior cerebellar peduncle (corrected P < 0.05). MRS found reduced NAA/Cr values in cerebellar vermis and hemisphere (corrected P < 0.05). Our findings could provide new insights into management of SCA36 patients. Detailed auxiliary examination are recommended to assess hearing or peripheral nerve impairment, and we should pay more attention to eye movement and cognitive changes in patients. Furthermore, for the first time, our multimodel neuroimaging evaluation generate a full perspective of brain function and structure in SCA36 patients. [ABSTRACT FROM AUTHOR]

The parallel architecture can improve the training speed of Deep learning models and it is beneficial to model optimization. This research designs Optimal Interleaved Distributed Architecture (OIDA). Its characteristics are (1) the data set that each child node participates in training is fixed and unique; (2) multiple approaches ensure that the model parameters of each child node participating in training each time are always optimal; (3) the computing units of each child node are interleaved for training without stopping. The architecture can be deployed as Single Machine Parallel (SMP) or Multi Machine Distributed (MMD), or a combination of both. The experimental results show that its efficiency is obvious in a multi-machine multi-card environment, and the model speed of training millions of parameters in a 5-machine 10-card lightweight (Graphics Processing Unit (GPU) of 2GB memory) cluster can reach megapixels/s. When training the same amount of training data, GPU can process data faster than Central Processing Unit (CPU) with the same number of clusters. 4-machine 4-core GPU parallel saves 65.61% of time compared with 4-machine 4-core CPU parallel, while 4-machine 8-core GPU saves 83.32% of time compared with 4-machine 4-core CPU parallel. For polarized Synthetic Aperture Radar (SAR) Deep learning data sets, increasing the number of computers in the cluster can effectively save training time. In the experimental environment of this research, there is no situation that when the number of computers in the cluster increases due to network data transmission, the training time does not decrease. [ABSTRACT FROM AUTHOR]

Reasonably regulating electronic coupling to promote charge transfer and exciton separation has been regarded a promising approach in catalysis. The material engineering of van der Waals heterojunction (vdWsH) based on two-dimensional (2D) materials would be a potential way to optimize the as-prepared extrinsic physicochemical characteristics. However, it was still an almost uncultivated land waiting for exploration in catalysis. Herein, we introduced the inert h-boron nitride (h-BN) in non-metal reduced graphene oxide (GN) catalysts and constructed BN-GN vdWsH. The theoretical calculation demonstrated that the h-BN can effectively modify the electronic properties of graphene. With the introduction of h-BN, the BN-GN vdWsH can obviously enhance the catalytic activity of Li-CO2 battery. The existence of BN-GN vdWsH can reduce the overpotential more than 700 mV compared with reduced graphene oxide during the CO2 reduction reaction (CO2RR) and CO2 evolution reaction (CO2ER), and it extended cyclic stability more than three times, which was one of the most outstanding non-metallic catalysts. The reasonable structure design made it work as a high efficient electrocatalyst, which shed light on the development for functional treatment of catalytic materials. [ABSTRACT FROM AUTHOR]

Flavonoid metabolism serves an important function in plant growth and development. In this study, we selected 20 varieties of apple lines, 10 green and ten red branches, from the plant nursery of Qingdao Agriculture Academy. Metabolite analysis revealed that large amounts of anthocyanins accumulated in the purple-red branches of M. ‘Pink spire’. Real-time polymerase chain reaction showed that the expression of the flavonol synthase gene MdFLS1 was over 1500-fold higher in M. ‘Pink spire’ than in the other varieties. A single base A was inserted at the first three bases of the active binding site of MdFLS1 to prove that the purple-red colour of apple leaves and stems in M. ‘Pink spire’ may be caused by the inactivation of MdFLS1 protein. The results of in vitro enzymatic reaction revealed that the MdFLS1 protein lost its activity. MdFLS1 was expressed in Arabidopsis thaliana to explore further its functions. High-expression wild-type strains (OE1 and OE2) and high-expression strains of A-base insertion (A-OE1 and A-OE2) were obtained. Compared with the wild-type strains, the overexpression lines showed lighter tissue colour and less accumulation of anthocyanins. However, A-OE1 and A-OE2 showed no difference in colouration. In conclusion, we speculated that the MdFLS1 gene in M. ‘Pink spire’ cannot bind flavonoids, triggering the synthesis of anthocyanins in another branch of the flavonoid metabolic pathway and resulting in the purple-red colouration of apple leaves and stems. These results suggest that MdLS1 is a potential genetic target for breeding high-flavonoid apples in future cultivar development. [ABSTRACT FROM AUTHOR]

Objective: To systematically evaluate the protective effects of Humulus lupulus L. extract (HLE) on osteoporosis mice. Methods: In vivo experiment, a total of 35 12-week-old female ICR mice were equally divided into 5 groups: the sham control group (sham); the ovariectomy with vehicle group (OVX); the OVX with estradiol valerate [EV, 0.2 mg/(kg•d)] the OVX with low- or high-dose HLE groups [HLE, 1 g/(kg•d) and 3 g/(kg•d)], 7 in each group. Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks. Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography, and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay (ELISA) kits. In vitro experiment, osteoblasts and osteoclasts were treated with HLE at doses of 0, 4, 20 and 100 µg/mL. Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed. Results: Compared with the OVX group, HLE exerted bone protective effects by the increase of estradiol (P<0.05), the improvement of cancellous bone structure, bone mineral density (P<0.01) and the reduction of serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), bone gla-protein, c-terminal telopeptides of type I collagen (CTX-I) and deoxypyridinoline levels (P<0.01 for all). In vitro experiment, compared with the control group, HLE at 20 µg/mL promoted the cell proliferation (P<0.01), and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts (both P<0.05). HLE at 100 µg/mL increased the osteoblastic ALP activities, and HLE at all dose enhanced the extracellular matrix mineralization (both P<0.01). Furthermore, compared with the control group, HLE at 20 µg/mL and 100 µg/mL inhibited osteoclastic TRAP activity (P<0.01), and reduced the expression of matrix metalloproteinase-9 and cathepsin K (both P<0.05). Conclusion: HLE may protect against bone loss, and have potentials in the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

Environmental DNA (eDNA) techniques show promise in facilitating the study and conservation of threatened species. The advantages of high sensitivity and high efficiency have been demonstrated by studies across various taxa. Asian turtles, one of the most threatened vertebrate groups, are facing extinction due to overexploitation for use as traditional Chinese medicine, food, and pets. Most species are extirpated across their ranges, but Hong Kong is unique because wild turtle populations persist. Due to the rarity and secretiveness of turtles, data on the location and size of populations are incomplete, even for a small place like Hong Kong. The result is that research and conservation are hindered. In this study, quantitative PCR eDNA assays were developed for three turtle species: two native [big-headed turtle (Platysternon megacephalum) and Chinese softshell turtle (Pelodiscus sinensis)] and one invasive [red-eared slider (Trachemys scripta elegans)]. For each assay, we tested species specificity, optimized reactions, and benchmarked analytical sensitivity for eDNA surveys. The assays will help in the conservation of Hong Kong turtles by identify priority sites for protection and research, provide another tool for population monitoring, and clarify the impact of the invasive T. s. elegans on native species. [ABSTRACT FROM AUTHOR]

Feeder cells like mouse embryonic fibroblasts (MEFs) have been widely applied for culture of pluripotent stem cells, but their roles remain elusive. Noticeably, ESCs cultured on the feeders display transcriptional heterogeneity. We investigated roles of feeder cells by examining the telomere maintenance. Here we show that telomere is longer in mESCs cultured with than without the feeders. mESC cultures without MEF feeders exhibit telomere loss, chromosomal fusion, and aneuploidy with increasing passages. Notably, feeders facilitate heterogeneous transcription of 2-cell genes including Zscan4 and telomere elongation. Moreover, feeders produce Fstl1 that together with BMP4 periodically activate Zscan4. Interestingly, Zscan4 is repressed in mESCs cultured in 2i (inhibitors of Mek and Gsk3β signaling) media, associated with shorter telomeres and increased chromosome instability. These data suggest the important role of feeders in maintaining telomeres for long-term stable self-renewal and developmental pluripotency of mESCs. [ABSTRACT FROM AUTHOR]

Cysteine protease cathepsins have traditionally been considered as lysosome-restricted proteases that mediate proteolysis of unwanted proteins. However, studies from the past decade demonstrate that these proteases are localized not only in acidic compartments (endosomes and lysosomes), where they participate in intracellular protein degradation, but also in the extracellular milieu, plasma membrane, cytosol, nucleus, and nuclear membrane, where they mediate extracellular matrix protein degradation, cell signalling, and protein processing and trafficking through the plasma and nuclear membranes and between intracellular organelles. Studies in experimental disease models and on cathepsin-selective inhibitors, as well as plasma and tissue biomarker data from animal models and humans, have verified the participation of cysteinyl cathepsins in the pathogenesis of many cardiovascular diseases, including atherosclerosis, myocardial infarction, cardiac hypertrophy, cardiomyopathy, abdominal aortic aneurysms, and hypertension. Clinical trials of cathepsin inhibitors in chronic inflammatory diseases suggest the utility of these inhibitors for the treatment of cardiovascular diseases and associated complications. Moreover, development of cell transfer technologies that enable ex vivo cell treatment with cathepsin inhibitors might limit the unwanted systemic effects of cathepsin inhibition and provide new avenues for targeting cysteinyl cathepsins. In this Review, we summarize the available evidence implicating cysteinyl cathepsins in the pathogenesis of cardiovascular diseases, discuss their potential as biomarkers of disease progression, and explore the potential of cathepsin inhibitors for the treatment of cardiovascular diseases. [ABSTRACT FROM AUTHOR]

In our research, a convenient exfoliation/restacking route was used to fabricate a sandwich-structured nanocomposite of Sr2Nb3O10/CoTMPyP [5,10,15,20-tetrakis(N-methylpyridinium-4-yl)porphyrinato cobalt] via electrostatic interaction between colloidal dispersion and cobalt porphyrin aqueous solution. The final self-assembled products were characterized by XRD, FTIR, UV-Vis, SEM, TEM, AFM, and ICP. During the exfoliation procedure, the well-dispersed Sr2Nb3O10- colloidal dispersion was obtained with the zeta potential value of - 44.2 mV. Additionally, the existence of unilamellar Sr2Nb3O10- nanosheet was evidenced by AFM, and zeta potential values of the reassembly process with the addition of CoTMPyP aqueous solution into the colloidal dispersion were measured by a Zetasizer Nano apparatus. Above all, the final Sr2Nb3O10/CoTMPyP hybrid film displayed excellent electro-catalytic activities towards hydrazine hydrate oxidation with peak potential at 0.158 V in pH 7.0 PBS indicated by CV measurements; moreover, a detection limit of 3.52 × 10-5 M was obtained in the concentration range of 5 × 10-5-9.9 × 10-4 M at a signal-to-noise ratio of 3.0. [ABSTRACT FROM AUTHOR]

Rational design and directed evolution have proved to be successful approaches to increase catalytic efficiencies of both natural and artificial enzymes. Protein dynamics is recognized as important, but due to the inherent flexibility of biological macromolecules it is often difficult to distinguish which conformational changes are directly related to function. Here, we use directed evolution on an impaired mutant of the proline isomerase CypA and identify two second-shell mutations that partially restore its catalytic activity. We show both kinetically, using NMR spectroscopy, and structurally, by room-temperature X-ray crystallography, how local perturbations propagate through a large allosteric network to facilitate conformational dynamics. The increased catalysis selected for in the evolutionary screen is correlated with an accelerated interconversion between the two catalytically essential conformational substates, which are both captured in the high-resolution X-ray ensembles. Our data provide a glimpse of an evolutionary trajectory and show how subtle changes can fine-tune enzyme function. [ABSTRACT FROM AUTHOR]

Basophils have been shown to be important players in promoting lupus nephritis (LN). However, the relationship between circulating basophil counts and renal pathology activity of LN remains unclear. In this retrospective study, 159 clinical and pathology samples from patients with biopsy-proven LN were analyzed. The renal activity and classification were evaluated according to renal pathology. The correlations between circulating basophil counts and renal pathology activity index were assessed. Overall, circulating basophil counts correlated with total systemic lupus erythematosus disease activity index (SLEDAI) score ( r = − 0.31), renal SLEDAI score ( r = − 0.35), activity index (AI) score( r = − 0.40), and renal histologic activity parameters ( p < 0.05, respectively). Compared with systemic lupus erythematosus (SLE) non-LN patients, the LN group had lower basophil counts (0.007 ± 0.007 vs. 0.011 ± 0.010 × 10/L, p = 0.04). Subgroup analyses revealed that the circulating basophil counts in group B (AI > 8) were significantly lower than that in group A (AI ≤ 8) (0.004 ± 0.006 vs. 0.009 ± 0.009 × 10/L, p < 0.001). The difference was still significant when eliminating the influence of SLEDAI. Significant differences were found in circulating basophil counts among LN pathology classification groups ( p < 0.01). Groups of classes III, IV, and V were more likely to have lower circulating basophil counts when compared with group of class I/II ( p < 0.05). These findings suggest a potential role of circulating basophil counts as a convenient and helpful marker for renal activity of LN. [ABSTRACT FROM AUTHOR]

Immunoglobulin G (IgG) is a major effector molecule of the human immune response, and aberrations in IgG glycosylation are linked to various diseases. However, the molecular mechanisms underlying protein glycosylation are still poorly understood. We present a data-driven approach to infer reactions in the IgG glycosylation pathway using large-scale massspectrometry measurements. Gaussian graphical models are used to construct association networks from four cohorts. We find that glycan pairs with high partial correlations represent enzymatic reactions in the known glycosylation pathway, and then predict new biochemical reactions using a rule-based approach. Validation is performed using data from a GWAS and results from three in vitro experiments. We show that one predicted reaction is enzymatically feasible and that one rejected reaction does not occur in vitro. Moreover, in contrast to previous knowledge, enzymes involved in our predictions colocalize in the Golgi of two cell lines, further confirming the in silico predictions. [ABSTRACT FROM AUTHOR]

Six isolates of Arthrobotrys musiformis and five isolates of Arthrobotrys robusta were assessed in in vitro test regarding the capacity of prey larvae of the natural mixed trichostrongylides. In 5 isolates of A. robusta, the decrease percentage of infective larvae (L3) of trichostrongylides ranged from 97.71%-99.98% and for the isolates of A. musiformis, 5 isolates ranged from 97.99%-99.95% and only NF015 isolate 60.72%. In the following, the isolate (NPS045) of A. musiformis was selected to assess its excretion time in feces after oral administration of goats. Regarding L3 reduction rate, results demonstrated by NPS045 at each time point after fungal administration were 31.65% (12 h), 51.25% (24 h), 41.07% (48 h), 6.44% (72 h), 0% (96 h) and (120 h) (p<0.05) respectively, when compared to the control group. In the plates of the treated groups, the presence of the isolate (NPS045) was detected in samples at 12, 24 and 48 h after the fungus dose and 72 h later was not done. All native isolates of nematophagous fungi, including 6 isolates of A. musiformis and 5 isolates of A. robusta were assessed in vivo regarding the capacity of supporting the passage through goat gastrointestinal tract. The 3 isolates of A. musiformis could be able to pass through the digestive tract of goats without complete loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 47.60% to 55.93%. The two isolates of A. robusta survived the passage and the percentage reduction of L3 in feces were 41.96% and 66.97%, respectively. The remaining isolates were negative for both the efficacy of L3 reduction and the fungal examination in feces. In this study, the native isolates whose efficacies are good in vivo test have preliminarily demonstrated to be potential for the biological control of small ruminant parasite. [ABSTRACT FROM AUTHOR]

The simulation models of the thermal and macrostructural evolutions during directional solidification of Ni-base single crystal (SX) turbine blades under high rate solidification (HRS) and liquid metal cooling (LMC) have been constructed using ProCAST software, coupled with a 3D Cellular Automaton Finite Element (CAFE) model. The models were used to investigate the tendencies of stray grain (SG) formation in the platform region of turbine blades fabricated by HRS and LMC techniques. The results reveal that the LMC technique can prohibit SG formation by smoothing the concaved isotherm and in turn alleviating the undercooling in the platform ends to let the dendrites fill up the undercooled zone before SG nucleation. The simulation results agreed well with the experimental results, indicating that these models could be used to analyze the macrostructural evolution or to optimize process parameters to suppress SG formation. Using these models, the critical withdrawal rate for casting SX turbine blades without SG formation were determined to be around 75 μm·s-1 and 100 μm·s-1 for HRS and LMC respectively, suggesting that LMC can be used as an efficient technique in fabricating SX turbine blades without any SG defect formation. [ABSTRACT FROM AUTHOR]

Low emotional support is associated with poor health outcomes. Engagement with face-to-face social networks is one way of increasing emotional support. However, it is not yet known whether engagement with proliferating electronic social networks is similarly associated with increased emotional support. Thus, the purpose of this study was to assess associations between social media use and perceived emotional support in a large, nationally-representative sample. In October 2014, we collected data from 1796 U.S. adults ages 19-32. We assessed social media use using both total time spent and frequency of visits to each of the 11 most popular social media platforms. Our dependent variable was perceived emotional support as measured by the brief Patient-Reported Outcomes Measurement Information System (PROMIS) emotional support scale. A multivariable model including all sociodemographic covariates and accounting for survey weights demonstrated that, compared with the lowest quartile of time on social media, being in the highest quartile (spending two or more hours per day) was significantly associated with decreased odds of having higher perceived emotional support (AOR 0.62, 95 % CI 0.40, 0.94). However, compared with those in the lowest quartile, being in the highest quartile regarding frequency of social media use was not significantly associated with perceived emotional support (AOR 0.70, 95 % CI 0.45, 1.09). In conclusion, while the cross-sectional nature of these data hinder inference regarding directionality, it seems that heavy users of social media may actually feel less and not more emotional support. [ABSTRACT FROM AUTHOR]

In order to improve the filling ability of large complex thin wall castings, the pouring temperature should be increased, but this will result in the grain coarsening. To overcome this problem, two kinds of grain refiners of Co-Fe-Nb and Cr-Fe-Nb ternary alloys, which contain high stability compound particles, were prepared. The effects of the refiners on the as-cast structures and tensile properties of the K4169 superalloy with different casting conditions were studied by analyzing specimens 110 mm long and 20 mm in diameter. Results showed that the mixture addition of the two refiners in the melt of K4169 can reduce the columnar grain region and decrease the equiaxed grain size greatly. After refinement, the amount of Laves phase decreases and its morphology changes from island to blocky structure. The carbides in the fine grain samples are fine and dispersive. Meanwhile, the porosity in specimens is decreased due to grain refinement. As a result, the yield strength, ultimate strength and the elongation of the specimens are increased. The grain refinement mechanisms are also discussed. [ABSTRACT FROM AUTHOR]

In this study, three kinds of modified ultra-fine ceramic powders marked A, B and C, which were prepared by each of three different modifiers mixing with a commercial SiC, were added to HT250 cast iron, respectively, and the effects of the modified ultra-fine ceramic powders on microstructure, mechanical properties and wear resistance were studied. Metallographic examination, tensile test, scanning electron microscopy, and three-dimensional surface topography were applied to analyze and compare the samples containing modified powder with the original samples. The results showed that the most obvious modification effect among the powders was seen in the sample containing powder A, with the graphite and eutectic cells being refined, the tensile strength being increased by 36.9%, and the wear resistance being improved by 45.5% and 47.2% under loads of 150 N and 300 N, respectively. The improvements of mechanical properties and wear resistance in the HT250 cast iron with the modified ultra-fine ceramic powders were attributed to the synergistic effect of the grain refinement with the powder acting as a hard particle phase and the lubrication by the graphite. [ABSTRACT FROM AUTHOR]

Being involved in many important biological processes, miRNAs can regulate gene expression by targeting mRNAs to facilitate their degradation or translational inhibition. Many miRNA sequencing studies reveal that miRNA variations such as isomiRs and "arm switching" are biologically relevant. However, existing standalone tools usually do not provide comprehensive, detailed information on miRNA variations. To deepen our understanding of miRNA variability, we developed a new standalone tool called "mirPRo" to quantify known miRNAs and predict novel miRNAs. Compared with the most widely used standalone program, miRDeep2, mirPRo offers several new functions including read cataloging based on genome annotation, optional seed region check, miRNA family expression quantification, isomiR identification and categorization, and "arm switching" detection. Our comparative data analyses using three datasets from mouse, human and chicken demonstrate that mirPRo is more accurate than miRDeep2 by avoiding over-counting of sequence reads and by implementing different approaches in adapter trimming, mapping and quantification. mirPRo is an open-source standalone program (https://sourceforge.net/projects/mirpro/). [ABSTRACT FROM AUTHOR]

Direct perfusion of three-dimensional cell-seeded biological scaffolds is known to enhance osteogenesis, which can be partly attributed to mechanical stimuli affecting cell proliferation and differentiation in the process of bone tissue regeneration. This study aimed to compare the hydrodynamic environment, including the distributions of fluid flow velocity, wall shear stress and pressure in pores filled with liquid, designed scaffold (DS), porous and biodegradable β-TCP ( β-tricalcium phosphate) based on freeze-drying scaffold (FS) and dog's femora scaffold (NS). Gravity condition, inlet velocities of 1, 10, 100 and 1000 μm/s and medium viscosities of 1.003, 1.45 and 2.1 mPas were applied as the initial conditions. With an inlet fluid velocity of 100m/s and a viscosity of 1.45 (10 Pas, the simulation results of maximal and average wall shear stress were 15.675 mPas and 3.223 mPas for DS, 67.126 mPas and 5.949 mPas for FS, and 20.190 mPas and 1.629 mPas for NS. Variations of inlet fluid velocity and fluid viscosity produced corresponding proportional changes in fluid flow velocity, wall shear stress and pressure. DS and FS were evaluated in terms of simulation results and microstructure using NS as a reference standard. This methodology allows a greater insight into the complex concept of tissue engineering and will likely help in understanding and eventually improving the fluid-mechanical aspects. [ABSTRACT FROM AUTHOR]

The effects of heat treatment for recovering microstructure of a Ni-based single crystal superalloy with carbon addition have been evaluated. The heat treatment resulted in increased levels of chemical homogeneity. All the samples experienced more ... coarsening than as-cast samples. Significant changes to as-cast carbide morphologies were observed. Script-type, MC carbide networks transformed during heat treatment to smaller, spherical Ta-rich MC carbides. Heat treatment caused significant MC carbide decomposition and formation of Cr-rich secondary carbides on or near to decomposed carbides in all modifications. The size of carbides after heat treatment was less than that of cast alloy obviously, and the distribution of carbides became more and more dispersion than in cast alloy. [ABSTRACT FROM AUTHOR]

The mechanism of stray grain formation at the platform of turbine blade simulator and the effect of withdrawal rate (V) on the stray grain phenomenon have been investigated using a macro-scale ProCAST coupled with a 3D Cellular Automaton Finite Element (CAFE) model. The results indicate that the stray grains nucleate at the edges of platform at V =150 μm·s-1 and 200 μm·s-1. Using ProCAST computer simulation software, it was proven that the stray grain formation is significantly dependent on the undercooling and the temperature field distribution in the platform. The macroscopic curvature of the liquidus isotherm becomes markedly concave with an increase in the withdrawal rate. The probability of stray grain formation at the edges of platform can be increased by increasing the withdrawal rate in the range of 70 μm·s-1 to 200 μm·s-1. [ABSTRACT FROM AUTHOR]

isThe mechanical property of extracellular matrix and cell-supporting substrates is known to modulate neuronal growth, differentiation, extension and branching. Here we show that substrate stiffness is an important microenvironmental cue, to which mouse hippocampal neurons respond and integrate into synapse formation and transmission in cultured neuronal network. Hippocampal neurons were cultured on polydimethylsiloxane substrates fabricated to have similar surface properties but a 10-fold difference in Young's modulus. Voltage-gated Ca2+ channel currents determined by patch-clamp recording were greater in neurons on stiff substrates than on soft substrates. Ca2+ oscillations in cultured neuronal network monitored using time-lapse single cell imaging increased in both amplitude and frequency among neurons on stiff substrates. Consistently, synaptic connectivity recorded by paired recording was enhanced between neurons on stiff substrates. Furthermore, spontaneous excitatory postsynaptic activity became greater and more frequent in neurons on stiff substrates. Evoked excitatory transmitter release and excitatory postsynaptic currents also were heightened at synapses between neurons on stiff substrates. Taken together, our results provide compelling evidence to show that substrate stiffness is an important biophysical factor modulating synapse connectivity and transmission in cultured hippocampal neuronal network. Such information is useful in designing instructive scaffolds or supporting substrates for neural tissue engineering. [ABSTRACT FROM AUTHOR]

Abstract Fintech has gained immense importance as a catalyst for economic growth, trade enhancement, and global prosperity. This study aims to comprehensively assess the influence and potential of Fintech in the Association of Southeast Asian Nations (ASEAN) countries. The research objective is to evaluate the levels of development in financial activities, technology infrastructure, and Fintech-enabling regulations across the region. A robust decision-making framework combining numerical and linguistic assessments is applied, utilizing the Distance-based CRiteria Importance Through Inter-criteria Correlation (DCRITIC) method and the Fuzzy extension of Evaluation based on Distance from Average Solution (F-EDAS approach). The findings reveal varying levels of development among ASEAN countries about Fintech. Governments and policymakers are urged to prioritize the creation of a supportive environment for Fintech innovation to spur economic growth, attract investments, and foster digital transformation. The study is limited because the weights of the key regulations have not been investigated.

Abstract The shift towards remote work has been expedited by the COVID-19 pandemic, and COVID-19 has increased the need to understand the factors affecting remote work productivity such as family–work conflict, work engagement, and self-efficacy. However, the previous research may not comprehensively capture the intricacies associated with remote work amidst the pandemic. This study proposes a model to explore the relationship between family–work conflict and work-from-home productivity based on role conflict and resource drain theories as well as the family–work-conflict literature. The quantitative approach was used. A questionnaire was distributed using a convenience sampling technique and a response rate of 90.1% (1177 respondents) was achieved. After data cleaning, 785 valid cases were analysed. SPSS 22 and AMOS 20 were used to test the descriptive statistics, reliability, and validity, and the proposed hypotheses were evaluated using Process Macro (Model 5). The findings found that family–work-conflict negatively affected work engagement, self-efficacy, and work-from-home productivity. The negative effect of family–work-conflict on work-from-home productivity was stronger for employees with more work-from-home days than those with fewer. The partial mediation of work engagement and self-efficacy was established. This study contributes to the understanding of remote work productivity during the pandemic, particularly for small and medium-sized enterprise employees. It highlights the regulatory role of working hours when working from home and examines the mediation of self-efficacy in the association between family–work conflict and work-from-home productivity. This study also confirms the gender differences in work-from-home productivity which has been previously inconsistent in the literature. Managerially, the research has practical implications for employers, managers, and the government. Employers should adopt family-friendly policies and offer training programmes to enhance work-from-home productivity. Employers need to pay extra attention to their female employees’ work and family responsibilities and guarantee positive working outcomes through online surveys and two-way communication strategies. Professional training and work-from-home skill development programmes should be provided to boost employee confidence and self-efficacy. Governments and employers should also consider implementing regulations on the duration of working-from-home to avoid negative impacts on work efficiency and family–work conflict.