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Due to the Jacobian matrix rank reduction near singularities, applying numerical methods to study PMs' motion stability at singularities is quite difficult. As a result, there is a scarcity of literature on the investigation of PMs' dynamic behaviors near singularities and the influence of kinematic parameters on the motion stability of PMs. To address the research gap related to the above issues, based on the Gerschgorin perturbation method, Hurwitz exact approach, and the Lyapunov dynamic stability theory, the influence of kinematic parameters and external loads on a PM's motion stability at singularities is studied for the first time. The theoretical analysis results reported in this paper reveal many previously undiscovered features beyond those derived from previous numerical methods, and indicate the limitations of some widely accepted statements. For example, increasing the angular speed of the movable platform can expand the range of the external loads that meet the motion stability at singular configurations. The prevailing notion in prior research that PMs are unable to support external loads in the direction of the gained DoF at singular configurations is only partially accurate. This pioneering research establishes a theoretical foundation for exploring a new real-time approach to avoid dynamic singularities by fully exploiting the influence mechanisms of kinematic parameters on PMs' dynamic stability at singularities. [ABSTRACT FROM AUTHOR]

Short-chain dehydrogenase/reductases (SDRs) belong to the NAD(P)(H)-dependent oxidoreductase superfamily, which have various functions of catalyzing oxidation/reduction reactions and have been generally used as powerful biocatalysts in the production of pharmaceuticals. In this study, ScSDR1 and ScSDR2, two new SDRs have been identified and characterized from Stachybotrys chartarum 3.5365. Substrate scope investigation revealed that both of the enzymes possessed the ability to oxidize β-OH to ketone specifically, and exhibited substrate promiscuity and high stereo-selectivity for efficiently catalyzing the structurally different prochiral ketones to chiral alcohols. These findings not only suggest that ScSDR1 and ScSDR2 might be potent synthetic tools in drug research and development, but also provide good examples for further engineered enzymes with higher efficiency and stereo-selectivity. [ABSTRACT FROM AUTHOR]

Chemotaxis is crucial for bacterial adherence and colonization of the host gastrointestinal tract. Previous studies have demonstrated that chemotaxis affects the virulence of causative pathogens and the infection in the host. However, the chemotactic abilities of non‐pathogenic and commensal gut bacteria have rarely been explored. We observed that Roseburia rectibacter NSJ‐69 exhibited flagella‐dependent motility and chemotaxis to a variety of molecules, including mucin and propionate. A genome‐wide analysis revealed that NSJ‐69 has 28 putative chemoreceptors, 15 of which have periplasmic ligand‐binding domains (LBDs). These LBD‐coding genes were chemically synthesized and expressed heterologously in Escherichia coli. Intensive screening of ligands revealed four chemoreceptors bound to mucin and two bound to propionate. When expressed in Comamonas testosteroni or E. coli, these chemoreceptors elicited chemotaxis toward mucin and propionate. Hybrid chemoreceptors were constructed, and results showed that the chemotactic responses to mucin and propionate were dependent on the LBDs of R. rectibacter chemoreceptors. Our study identified and characterized R. rectibacter chemoreceptors. These results will facilitate further investigations on the involvement of microbial chemotaxis in host colonization. [ABSTRACT FROM AUTHOR]

Objective: In this case–control study we aimed to investigate the intestinal microbiota profile of patients with Peutz‐Jeghers syndrome (PJS) and its association with polyp growth. Methods: Thirty‐two PJS patients and 35 healthy controls were enrolled. Fecal samples of all participants were collected for gut microbiota analysis via 16S rRNA gene (regions V3–V4) sequencing. SPSS version 22.0 and R software version 3.1.0 were used for the statistical analysis. Results: The richness was comparable, while the overall structure of the gut microbiota differed significantly between the PJS and control groups (weighted UniFrac, P = 0.001; unweighted UniFrac, P = 0.008). Significantly different abundances of two phyla, seven families, and 18 genera as well as twenty‐nine differentially enriched functional modules (false discovery rate, P < 0.05) between the two groups were identified. Morganella was positively associated with the median number of polyps (JPN; r = 0.96, P < 0.001) and number of newly discovered polyps in the jejunum between two recent endoscopic resections (JPNG; r = 0.78, P = 0.04). Desulfovibrio was positively associated with JPNG (r = 0.87, P = 0.01). Blautia was negatively associated with the median maximum size of polyps in the jejunum (JPS). Anaerostipes was negatively associated with JPN, JPNG and JPS. Clostridium XVIII and Fusicatenibacter were negatively associated with JPN and JPS, respectively. Conclusions: We found remarkably different gut microbiota of patients with PJS compared to healthy individuals and associations between specific fecal bacteria and clinical features of PJS. These findings may provide a new perspective for the management of PJS in clinical practice. [ABSTRACT FROM AUTHOR]

Based on covalent organic framework (COF) 1,3,5-tris-(4-formylphenyl)benzene-benzidine (TFPB-BD) in situ grown on Fe3O4 hollow microspheres and combined with gas chromatography-flame thermionic detector, a rapid and simple stir bar sorptive-dispersive microextraction method was developed for the determination of five triazole pesticides (paclobutrazol, hexaconazole, flusilazole, propiconazole, and tebuconazole). The synthesized TFPB-BD/Fe3O4 microspheres were characterized by transmission electron microscope, vibrating sample magnetometer, and thermogravimetric analysis, which showed that the material has strong magnetism and higher load capacity of COF. Under optimal conditions, the extraction equilibrium could be achieved within 9 min with detection limits of 0.17–1.48 μg L−1 (S/N = 3) and a linear range of 5–1000 μg L−1. The developed method was applied to the determination of trace triazole pesticides in apples, pears, and cabbages with recoveries from 81 to 117%. [ABSTRACT FROM AUTHOR]

Lycium barbarum L. (Solanaceae) seed oil (LBSO) exerts LBSO exerts protective effects in the testis in vivo and in vitro via upregulating SIRT3. This study evaluates the effects and mechanism of LBSO in the d-galactose (d-gal)-induced ageing testis. Male Sprague Dawley (SD) rats (n = 30, 8-week-old) were randomly divided into three groups: LBSO group (n = 10) where rats received subcutaneous injection of d-gal at 125 mg/kg/day for 8 weeks and intragastric administration of LBSO at 1000 mg/kg/day for 4 weeks, ageing model group (n = 10) received 8-week-sunbcutaneous injection of d-gal, and control group (n = 10) with same administration of normal saline. Lentivirus had established TM4 cells with SIRT3 overexpression or silencing before LBSO intervened in vitro. Treatment with LBSO, the levels of INHB and testosterone both increased, compared to ageing model. In vitro, we found the ED50 of LBSO was 86.72 ± 1.49 and when the concentration of LBSO at 100 μg/mL to intervene TM4 cells, the number of cells increased from 8120 ± 676.2 to 15251 ± 1119, and the expression of SIRT3, HO-1, and SOD upregulated. However, HO-1 and SOD were dysregulated by silencing SIRT3. On the other hand, the expression of AMPK and PGC-1α upregulated as an effect of SIRT3 overexpression by lentivirus, meanwhile the same increasing trend of that being found in cells treated with LBSO, compared to control group. LBSO alleviated oxidative stress in d-gal-induced sub-acutely ageing testis and TM4 cells by suppressing the oxidative stress to mitochondria via SIRT3/AMPK/PGC-1α. [ABSTRACT FROM AUTHOR]

The accurate taxonomic concept of the fungal Chaetomium species has been a hard work due to morphological similarity. Chemotaxonomy based on secondary metabolites is a powerful tool for taxonomical purposes, which could be used as an auxiliary reference to solve the problems encountered in the classification of Chaetomium. Among secondary metabolites produced by Chaetomium, cytochalasans and azaphilones exhibited a pattern of distribution and frequency of occurrence that establish them as chemotaxonomic markers for the Chaetomium species. This review attempted to elucidate the composition of the Chaetomium species and its relationship with classical taxonomy by summarizing the pattern of cytochalasans and azaphilones distribution and biosynthesis in the Chaetomium species. Key points: • Secondary metabolites from the genus Chaetomium are summarized. • Cytochalasans and azaphilones could be characteristic metabolites of the Chaetomium species. • Cytochalasans and azaphilones could be used to analyze for taxonomical purposes. [ABSTRACT FROM AUTHOR]

In this paper, the propagation of terahertz (THz) band of electromagnetic wave in left-handed materials (LHM) is simulated by using finite-difference time-domain (FDTD) method. The radar cross section (RCS) of target coated with left-handed materials under THz wave is calculated and compared with the radar cross section under microwave. The influence of electromagnetic parameters and left-handed material's slab thickness on the radar cross section under THz wave is discussed. The results show that the attenuation of THz wave in left-handed materials is so small. The radar cross section of THz wave is higher than that of microwave. These results provide some guidance for practical research on radar stealth and anti-stealth. [ABSTRACT FROM AUTHOR]

The function-based synthesis is a major approach for the artificial intelligence (AI)-based type synthesis of complex mechanisms. Due to a lack of knowledge to support functional reasoning from the behaviors of constituent basic mechanisms to the whole functional behaviors of complex mechanisms, the AI-based type synthesis of compound mechanisms is still a hard challenge. In this article, a grammar-based synthesis approach is proposed for carrying out the type synthesis of complex mechanisms. The grammar-based synthesis rules, in which the functional requirements and the topological connections among functional members are included, are defined with the aid of nine kinds of common functional requirements that are primarily exhibited by complex mechanical systems. Through assigning a function as well as topological connections to each element in the graphic carrier according to the grammar-based synthesis rules, the type synthesis process for complex mechanisms is carried out automatically. Since the divergence creative design technique is applied, this system can efficiently expand the synthesis solution space of complex mechanisms, and more innovative design schemes including generalized mechanisms can be figured out. For extremely complex mechanisms, though dividing the design problem into several smaller parts, and carrying out grammar-based synthesis process to each smaller part, respectively, then combing the generated schemes from each smaller part together, the function-based synthesis for extremely complex mechanisms can also be solved. Communicated by Kristopher Wehage. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the role of double‐balloon enteroscopy (DBE) in treating intestinal polyps in patients with Peutz‐Jeghers syndrome (PJS). Methods: All patients diagnosed with PJS who underwent a polypectomy under DBE from October 2006 to December 2018 were enrolled. Their clinical records, including surgical history, the method of DBE insertion, the number of DBE procedures, and the maximum size and number of the resected polyps, were retrospectively reviewed. Results: Altogether 97 patients were enrolled. For both antegrade and retrograde DBE the maximum size of the resected polyps during the second hospitalization was significantly smaller than that during the first hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [3.63 ± 0.92] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [2.95 ± 1.95] cm, P = 0.03), but was significantly larger than that during the third hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [0.88 ± 0.70] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [0.46 ± 0.40] cm, P = 0.048). The interval between the second and third hospitalizations was significantly longer than that between the first and second hospitalizations ([899.00 ± 382.12] days vs [537.27 ± 326.28] days, P = 0.027). The success rate of total enteroscopy was 58.3% (28/48), which was not affected by a history of laparotomy (61.5% vs 52.4%, P = 0.528). The complication rate was 4.4%. Conclusion: DBE is clinically safe and effective for the diagnosis and treatment of intestinal polyps in patients with PJS. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the efficacy of homemade tolcapone in treatment of patients with Parkinson's disease (PD). Eighty patients with PD were subjected to randomized, double-blind, placebo-controlled and parallel-group study. PD patients were randomly divided into the tolcapone treatment group (41 cases) and placebo group (39 cases). Each patient received 1 pill of tolcapone or placebo, 3 times per day for 26 weeks. Efficacy was evaluated using the internationally used unified Parkinson's disease rating scale (UPDRS) scoring system for PD symptoms. After the treatment for 26 weeks, the cognitive function, tremor, muscle stiffness, voluntary movement and autonomic nerve symptoms were compared between the two groups using UPDRS scores. Compared with the placebo group, cognitive function, muscle stiffness, voluntary movement and autonomic nerve symptoms were compared between the two group using UPDRS scores. Compared with the placebo group, cognitive function, muscle stiffness and voluntary movement reduction were significantly improved in patients of the tolcapone group (P<0.05). However, no significant differences in UPDRS scores of autonomic nerve symptoms and tremor were found between two groups after treatment (P>0.05). Tolcapone, a catechol-O-methyl transferase (COMT) inhibitor, can improve the motor function of patients with PD, especially exercise and muscle stiffness. Tolcapone can also improve the cognitive function of patients. [ABSTRACT FROM AUTHOR]

This paper deals with an inverse problem of identifying the source coefficient in degenerate parabolic equations. On the basis of extremum principle, the uniqueness of the proposed problem is obtained. The difference scheme for the direct problem is got by using the finite volume method and the corresponding stability is also proved. An iteration scheme of the Landweber type is applied to handle the numerical solution. In the end, several numerical experiments are performed to test the validity of the scheme. The numerical results show that the method is stable and the unknown function is recovered very well when iterative parameter α and iterative times are matching appropriately. [ABSTRACT FROM AUTHOR]

Aberrant DNA methylation of various genes has been identified to be associated with disease progression in chronic myeloid leukemia (CML). Our study was intended to investigate DLX4 methylation pattern in different clinical stages of CML and further determine its role in regulating DLX4 expression. Real-time quantitative methylation-specific PCR and bisulfite sequencing PCR were applied to detect DLX4 methylation. 5-aza-2′-deoxycytidine (5-aza-dC) was used for demethylation studies. DLX4 was significantly hypermethylated in CML patients ( P = 0.002) especially in blastic phase (BC) stage ( P < 0.001) as compared with controls. Moreover, DLX4 methylation level in BC stage was significantly higher than in chronic phase (CP) stage ( P < 0.001). DLX4 methylation density was significantly increased during the progression of CML among the tested two patients ( P < 0.001). DLX4 hypermethylation occurred with the highest incidence in BC stage (83%), lower incidence in acute phase (AP) stage (43%), and the lowest incidence in CP stage (26%) ( P = 0.001). Moreover, t(9; 22) with additional alteration cases had significantly higher frequency of DLX4 hypermethylation compared with the other cytogenetics ( P = 0.010). Significantly negative correlation was observed between DLX4 methylation and DLX4-TV2 (the shorter DLX4 isoform) expression (R = −0.382, P = 0.001, n = 78) but not between DLX4 methylation and BP1 (the longer DLX4 isoform) expression (R = 0.134, P = 0.244, n = 78) in CML patients. Both DLX4-TV2 and BP1 mRNA were significantly increased after 5-aza-dC treatment in K562 cell line ( P < 0.001). Our study indicated that hypermethylation of DLX4 correlated with disease progression of CML. Moreover, DLX4 expression was regulated by its methylation in CML. [ABSTRACT FROM AUTHOR]

Developing multifunctional metal–organic frameworks (MOFs) is a new research trend. MOFs have shown remarkable performances in both proton conduction and fluorescence sensing, but the MOFs integrating the two performances are scarce. Herein, a Co-MOF, [Co6(oba)4(Hatz)(atz)(H2O)2(μ3-OH)2(μ2-OH)]·H2O (1, H2oba = 4,4-oxybis(benzoic acid), Hatz = 5-amino-1H tetrazole), has been assembled by Co2+ ions with H2oba and Hatz ligands, providing a unique example of multifunctional MOFs with both proton conduction and fluorescence sensing performances. The framework of 1 displays a pillar-layer structure built by the oba ligand as a pillar and a layer composed of Co-clusters and atz linkers. Because large-scale single crystals of 1 were successfully synthesized, the proton conduction ability of 1 was investigated using single crystal samples. 1 exhibits highly anisotropic conduction with conductivity values of 1.1 × 10−3 S cm−1 along the [001] direction and 9.1 × 10−6 S cm−1 along the [010] direction at 55 °C and 95% RH, respectively. Meanwhile, the fluorescence sensing of 1 towards metal ions was studied in aqueous solutions. Attractively, 1 may sensitively and selectively detect Fe3+ ions in the presence of other interfering ions by fluorescence quenching. [ABSTRACT FROM AUTHOR]

It is difficult to simulate the explosive detonation of multi-lighter points and describe the assembling energy of detonation waves with the existent finite element methods. Particularly, computational efficiency and precision of the finite element methods are limited due to mesh distortion. Therefore, the explosive detonation of 2 lighters and even more lighters was numerically simulated with the material point method based on the explicit integration algorithm, to give results fitting the theoretical solution well. The proposed method not only avoids the remeshing procedure for distorted elements, but also makes an effective way to the numerical simulation of the explosive detonation. [ABSTRACT FROM AUTHOR]

Muscle stem cells facilitate the long-term regenerative capacity of skeletal muscle. This self-renewing population of satellite cells has only recently been defined through genetic and transplantation experiments. Although muscle stem cells remain in a dormant quiescent state in uninjured muscle, they are poised to activate and produce committed progeny. Unlike committed myogenic progenitor cells, the self-renewal capacity gives muscle stem cells the ability to engraft as satellite cells and capitulate long-term regeneration. Similar to other adult stem cells, understanding the molecular regulation of muscle stem cells has significant implications towards the development of pharmacological or cell-based therapies for muscle disorders. This Cell Science at a Glance article and accompanying poster will review satellite cell characteristics and therapeutic potential, and provide an overview of the muscle stem cell hallmarks: quiescence, self-renewal and commitment. [ABSTRACT FROM AUTHOR]

Objective: We conducted the present meta-analysis to investigate whether single-nucleotide polymorphisms (SNPs) in the SUMO1 gene contribute to the risk of nonsyndromic cleft lip with or without palate (NSCL/P). Method: The Web of Science (1945-2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966-2013), EMBASE (1980-2013), CINAHL (1982-2013), and the Chinese Biomedical Database (CBM) (1982-2013) were searched without language restrictions. Meta-analysis was performed with the use of the STATA statistical software. Results: Six studies with a total of 1381 NSCL/P patients and 2054 control subjects were included. Twenty-seven functional polymorphisms in the SUMO1 gene were assessed. Our results indicated that SUMO1 genetic polymorphisms were correlated with an increased risk of NSCL/P. Subgroup analysis by the SNP type indicated that 4 functional polymorphisms (rs12470401 T>C, rs16838917 A>G, rs12470529 A>G, and rs7572505 A>G) in the SUMO1 gene might be strongly correlated with NSCL/P risk. Furthermore, ethnicity-stratified analysis demonstrated that SUMO1 genetic polymorphisms were closely related to an increased risk of NSCL/P among both Asians and Caucasians. Conclusion: Our findings provide empirical evidence that SUMO1 genetic polymorphisms might be strongly involved in the etiology of NSCL/P, especially for rs12470401 T>C, rs16838917 A>G, rs12470529 A>G, and rs7572505 A>G polymorphisms. [ABSTRACT FROM AUTHOR]

Cell-based therapies for degenerative diseases of the musculature remain on the verge of feasibility. Myogenic cells are relatively abundant, accessible, and typically harbor significant proliferative potential ex vivo. However, their use for therapeutic intervention is limited due to several critical aspects of their complex biology. Recent insights based on mouse models have advanced our understanding of the molecular mechanisms controlling the function of myogenic progenitors significantly. Moreover, the discovery of atypical myogenic cell types with the ability to cross the blood-muscle barrier has opened exciting new therapeutic avenues. In this paper, we outline the major problems that are currently associated with the manipulation of myogenic cells and discuss promising strategies to overcome these obstacles. [ABSTRACT FROM AUTHOR]

The aim of this work is to study the method of explosive welding to produce niobium-steel composite plate, which is used in nuclear industry equipment material manufacturing. The welding parameters were determined by weldability window, and numerical simulation was used to predict the wave shape of the welding interface. The morphology of the interface wave was observed by scanning electron microscope. Measured element distribution near the interface. The experimental samples were investigated using mechanical tests. The results show that the welding parameters optimized by theory and numerical simulation can be used to obtain a niobium-steel composite plate with better welding quality. It can be proved that the welding quality is better by observing the interface wave and testing the mechanical properties; it can be seen that the melting zone of the welding interface is composed of niobium and steel by the composition analysis instrument. The morphology of the welding interface wave is consistent with the numerical simulation results, and the numerical simulation shows the changes of temperature, strain, and stress during the welding process. [ABSTRACT FROM AUTHOR]

Immune response in plants is tightly regulated by the coordination of the cell surface and intracellular receptors. In animals, the membrane attack complex/perforin-like (MACPF) protein superfamily creates oligomeric pore structures on the cell surface during pathogen infection. However, the function and molecular mechanism of MACPF proteins in plant pathogen responses remain largely unclear. In this study, we identified an Arabidopsis MACP2 and investigated the responsiveness of this protein during both bacterial and fungal pathogens. We suggest that MACP2 induces programmed cell death, bacterial pathogen resistance, and necrotrophic fungal pathogen sensitivity by activating the biosynthesis of tryptophan-derived indole glucosinolates and the salicylic acid signaling pathway dependent on the activity of enhanced disease susceptibility 1 (EDS1). Moreover, the response of MACP2 mRNA isoforms upon pathogen attack is differentially regulated by a posttranscriptional mechanism: alternative splicing. In comparison to previously reported MACPFs in Arabidopsis, MACP2 shares a redundant but nonoverlapping role in plant immunity. Thus, our findings provide novel insights and genetic tools for the MACPF family in maintaining SA accumulation in response to pathogens in Arabidopsis. [ABSTRACT FROM AUTHOR]

Satellite cells are a heterogeneous population of stem and progenitor cells that are required for the growth, maintenance and regeneration of skeletal muscle. The transcription factors paired-box 3 (PAX3) and PAX7 have essential and overlapping roles in myogenesis. PAX3 acts to specify embryonic muscle precursors, whereas PAX7 enforces the satellite cell myogenic programme while maintaining the undifferentiated state. Recent experiments have suggested that PAX7 is dispensable in adult satellite cells. However, these findings are controversial, and the issue remains unresolved. [ABSTRACT FROM AUTHOR]

The appearance design is one of the critical factors in the successful marketing of the consumptive products used in our daily lives. The feature parameter-based modelling technique supplied by most CAD software systems is an efficient and valid means of constructing 3D geometric models and the apparent surfaces of products. For understanding the relations between the feature parameters and the form-image sensation of the appearances corresponding to the modelling and controlling feature parameters, taking domestic sewing machines as an example, the effects of feature parameters on the form-image sensation of products are investigated. At first, the 3D apparent surfaces of domestic sewing machines are modelled with 18 form feature parameters based on the parameter-based function provided by the UGs software. Then, seventy-two 3D apparent style samples are obtained by changing randomly the values of the form feature parameters. Through a questionnaire investigation of these samples corresponding to the five form-image evaluation values of word-pairs, the form-image aesthetic evaluation BPN system for domestic sewing machines is set up. With the aid of this BPN system, the form-image sensation curves going with the values of the form feature parameters are figured out. By selecting the suitable values of the feature parameters based on these curves, the customer's specific aesthetic requirements can be understood and met in the early design stage of product developments. [ABSTRACT FROM AUTHOR]

Silica sulfuric acid has been utilized as an efficient heterogeneous recyclable catalyst for Knoevenagel condensation between poorly reactive β-diketones and aldehydes under solvent-free conditions. This protocol also works well with more reactive β-ketoesters. The condensation is efficient, clean, and mild. The scope and generality of the Knoevenagel condensation were investigated. The procedure led only to the Knoevenagel product, and no side product derived from a subsequent Michael addition of β-diketone to alkene was detected at rt. Increasing temperature led to a subsequent Michael addition, and it was applied to the efficient synthesis of 9-aryl-1,8-dioxo-octahydroxanthene derivatives. [ABSTRACT FROM AUTHOR]

Abstract: A steady-state model was established to simulate EDI process for producing ultrapure water (MixEDI), the dilute compartment of which is filled with mixed cation and anion-exchange resins. By calculating the mathematical model which includes water dissociation mechanism, ionic status of ion-exchange resin, concentration polarization status and the concentration distribution of water dissociation products are obtained. The influence of water dissociation on the current efficiency, removal rate and pH value of EDI effluent is investigated. The existence of water dissociation catalyst at anion-exchange membrane (AM) makes the water dissociation current of the AM much larger than that of CM. The result is that the amount of electro-regenerated cation-exchange resins is much larger than that of anion resins. This is the reason why the removal rate of salt cation much larger than that of salt anion in EDI for producing ultrapure water. Thus, at the target percentage removal, water dissociation at AM surface is excessive and the one at CM surface is insufficient. We assume that there is also some water dissociation catalyst at CM surface. It is found that the improved water dissociation at CM could increase the percentage removal of salt anions and the current efficiency. [Copyright &y& Elsevier]

Abstract: The electrodeionization process (EDI) is usually operated at overlimiting current density, and is thus characterized by water dissociation and concentration polarization. We attempt to study the useful and harmful effects of water dissociation on the EDI process. A numerical steady state model was established to simulate the process of EDI, accounting for the effects of water dissociation. The differences in concentration polarization of membranes were investigated to study the effects of water dissociation on cation and anion membranes. Protons produced by water dissociation caused the resin to transform into the H-form. The H-form resin, which has high conductivity and high transport number, depletes protons in the interstitial solution. This explains the experimentally detected phenomenon that at high current densities, the pH value of the effluency of the dilute compartment (DC) stops decreasing when current increases. We suggest that the useful role of water dissociation in EDI is due to the H-form resin bringing more salt cations of the interstitial solution into the resin phase, thus producing a high conductivity channel for the electro-migration of the salt cations. This mechanism avoids the decrease in salt ion conductivity brought about by concentration polarization. The disadvantageous effect of concentration polarization on the transportation of salt ions in interstitial solution is thus lessened. An intermediate point between the useful and harmful effects of water dissociation was determined by the dependence of current efficiency and removal rate for both cations and anions as a function of current density. [Copyright &y& Elsevier]

Abstract: In this paper, electric field assisted fabrication of membrane electrode assemblies (MEAs) for fuel cells is proposed, with the aim of improving the electronic and ionic connections in the catalyst layers and increasing the efficiency of catalyst utilization. Anodic and cathodic electrodes have been prepared by the perpendicular application of a low-frequency ac electric field to the catalyst ink spread on the surface of a gas diffusion layer (GDL) while the ink is drying. The thus prepared electrodes were hot-pressed onto a Nafion membrane to form the MEAs. Direct methanol fuel cells (DMFCs) with the electric field-treated MEAs (E-MEA) showed a substantial improvement in performance as compared with common MEAs (C-MEA) without electric field treatment. Under the same operating conditions, the maximum power density of a DMFC was increased from 42.3 to 60.0mWcm−2 when a C-MEA was replaced by an E-MEA treated with a 5000Vcm−1 and 0.1Hz ac electric field. Electrochemical impedance spectroscopy (EIS) measurements have shown that the through-plane ohmic resistances in the E-MEAs are lower than that in the C-MEA, while both the electronic and ionic resistances of the catalyst layer in the in-plane direction are higher for the E-MEAs, suggesting the formation of an oriented structure in the catalyst layers under the electric field treatment. EIS measurements have also shown that both the total reaction resistance and the anode reaction resistance in the E-MEAs are lower than in the C-MEA. Based on cyclic voltammetry (CV) data, it has been shown that Pt utilization in the cathode reaches a maximum of 62% for the E-MEA, as opposed to 37% for the C-MEA. [Copyright &y& Elsevier]

Abstract: The variable geometry parallel manipulator (VGPM) is a kind of manipulator that is suitable to change the spatial distribution of a variable geometry body (VGB). In the VGPM, the Stewart platform is utilized as a driving mechanism, and a number of spatial RSRR kinematic chains, which connect with the base frame and the top platform through revolute pairs, respectively, guide the rigid plates with spatially shaped inner surfaces to form the envelope of the VGB. The inverse kinematics problem of the VGPM is to determine every actuator displacement of the Stewart platform for given the outlet area and deflection angle of the VGB. In this paper, we present a method to solve this kind of inverse kinematics problem. At first, we present an assumption of the double semi-ellipses approximate distribution model of the VGB to determine the approximate position and orientation of the top platform. Through analysis of the deviations between the approximate distribution model and the given distribution parameters of the VGB, after making the compensation of the deviations, we obtain the corrected inverse kinematic solution of the VGPM with acceptable tolerance. [Copyright &y& Elsevier]

This paper presents a rules-based computerized symbolic carrier regeneration method for mechanical system conceptual design. In this method, design requirements of mechanical systems are expressed by regeneration rules which are composed mainly of symbols and logical codes; non-isomorphic graphs are chosen to be graphic carriers for symbolic carrier regeneration process; in each regeneration step, similarity identification needs to be done on symbolic carrier elements-links, so as to prevent redundant schemes. General design requirements can be expressed by simple Boolean calculation (AND, OR), relation calculation (adjacent, overlapping, topological relationship) and functional elements (concepts). Based on computer and object oriented encapsulation technology, the method can solve general conceptual design problems of mechanical systems. Designers need not know much about specialized knowledge and can fulfill design process of mechanical products. [Copyright &y& Elsevier]

Purpose: As a vital component of the hepatitis B virus (HBV) nucleocapsid, HBV core protein (HBC) contributes to hepatocarcinogenesis. Here, we aimed to assess the effects of RANGAP1 and KDM2A on tumorigenesis induced by HBC. Methods: Co-immunoprecipitation (Co-IP) combined with mass spectrometry were utilized to identify the proteins with the capacity to interact with HBC. The gene and protein levels of RANGAP1 and KDM2A in hepatocellular carcinoma (HCC) and HBV-positive HCC tissues were evaluated using different cohorts. The roles of RANGAP1 and KDM2A in HCC cells mediated by HBC were investigated in vitro and in vivo. Co-IP and western blot were used to estimate the interaction of HBC with RANGAP1 and KDM2A and assess RANGAP1 stabilization regulated by HBC. Results: We discovered that HBC could interact with RANGAP1 and KDM2A, the levels of which were markedly elevated in HCC tissues. Relying on RANGAP1 and KDM2A, HBC facilitated HCC cell growth and migration. The increased stabilization of RANGAP1 mediated by HBC was relevant to the disruption of the interaction between RANGAP1 and an E3 ligase SYVN1. RANGAP1 interacted with KDM2A, and it further promoted KDM2A stabilization by disturbing the interaction between KDM2A and SYVN1. HBC enhanced the interaction of KDM2A with RANGAP1 and upregulated the expression of KDM2A via RANGAP1 in HCC cells. Conclusions: These findings demonstrate a novel mechanism by which HBC facilitates hepatocarcinogenesis. RANGAP1 and KDM2A could act as potential molecular targets for treating HBV-associated malignancy. [ABSTRACT FROM AUTHOR]

Large-scale explosive welded composite plates are important materials for nuclear fusion reactor vessels, and have high requirements for mechanical properties and crack detection tests. In order to meet the requirements, titanium/steel explosive welded composite plates were manufactured under different gas media, and the effect of gaseous media on the interfacial microstructure and mechanical properties of the composite plates was evaluated. The results show that there are significant differences in the interface morphology and mechanical properties of the explosive welded composites under different gaseous media. Unlike traditional explosive welding under air, a low density helium medium smooths the welding process and creates a more stable periodic wave at the interface. In addition, helium gas as an inert gas effectively inhibits the formation of oxides at the interface and improves the mechanical properties and welding quality. [ABSTRACT FROM AUTHOR]

Background and aim: Capsule retention is the most common adverse event associated with video capsule endoscopy. The use of double-balloon enteroscopy-assisted capsule endoscope retrieval has been increasingly reported in recent years. However, evidence is limited regarding its success rate, associated factors, and subsequent clinical outcomes. Methods: A systematic review of relevant studies published before January 2019 was performed. Successful retrieval rate and associated factors, rate of endoscopic balloon dilation, and outcomes after double-balloon enteroscopy were summarized and pooled. Results: Within 154 associated original articles, 12 including 150 cases of capsule retrieval by double-balloon enteroscopy were included. The estimated pooled successful retrieval rate was 86.5% (95% confidence interval, 75.6–95.1%). Anterograde approach and capsules retained in the jejunum or trapped by malignant strictures were associated with a higher successful retrieval rate than the retrograde approach (62/83 [74.7%] vs. 10/38 [26.3%], p <.001) and capsules retained in the ileum (41/41 [100.0%] vs. 43/58 [74.1%], p <.001) or trapped by benign strictures (21/21 [100.0%] vs. 65/83 [78.3%], p =.043). Endoscopic balloon dilation was performed in 38.8% (95% confidence interval, 22.3–56.3%) of patients with benign strictures. Two perforations (1.3%) were reported as severe adverse events after double-balloon enteroscopy. A significantly lower surgery rate was found among cases with successful video capsule removal compared with unsuccessful cases (7.2% vs. 38.5%, p =.002). Conclusions: Double-balloon enteroscopy is feasible and safe for removing retained video capsule endoscopes, and its use could decrease the need for surgery in patients with benign strictures and facilitate subsequent surgery in patients with malignant strictures. [ABSTRACT FROM AUTHOR]

Background: Methylation-associated SOX family genes have been proved to be involved in multiple essential processes during carcinogenesis and act as potential biomarkers for cancer diagnosis, staging, prediction of prognosis, and monitoring of response to therapy. Herein, we revealed SOX30 methylation and its clinical implication in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Results: In the discovery stage, we identified that SOX30 methylation, a frequent event in AML, was negatively associated with SOX30 expression and correlated with overall survival (OS) and leukemia-free survival (LFS) in cytogenetically normal AML among SOX family members from The Cancer Genome Atlas (TCGA) datasets. In the validation stage, we verified that SOX30 methylation level was significantly higher in AML even in MDS-derived AML compared to controls, whereas SOX30 hypermethylation was not a frequent event in MDS. SOX30 methylation was inversely correlated with SOX30 expression in AML patients. Survival analysis showed that SOX30 hypermethylation was negatively associated with complete remission (CR), OS, and LFS in AML, where it only affected LFS in MDS. Notably, among MDS/AML paired patients, SOX30 methylation level was significantly increased in AML stage than in MDS stage. In addition, SOX30 methylation was found to be significantly decreased in AML achieved CR when compared to diagnosis time and markedly increased in relapsed AML when compared to the CR population. Conclusions: Our findings revealed that SOX30 methylation was associated with disease progression in MDS and acted as an independent prognostic and predictive biomarker in AML. [ABSTRACT FROM AUTHOR]

A nonuniform frequency selective surface (FSS)-backed reflectarray with both amplitude and phase controls for beam shaping is presented in this paper. In the process of element design, a dual-resonance reflectarray element backed by a loop FSS is studied. The proposed reflectarray element can achieve a reflection phase range of 570° and an amplitude control range over 10 dB, by tuning the dimensions of the upper reflectarray and lower FSS layers. In the process of reflectarray synthesis, a complex amplitude synthesis technique, based on the modified alternating projection method, is developed to take into account the physically realizable amplitude and phase controls of the FSS-backed element for optimizing the amplitude and phase distributions on the reflectarray aperture. A nonuniform FSS-backed $16\times 16$ -element reflectarray with a sector beam in the azimuth plane and a pencil beam in the elevation plane is designed and fabricated. The simulation and measured results reveal that the proposed reflectarray antenna offers distinguishing features in terms of high-quality pattern with lower sidelobe level, lower cross polarization as well as lower radar cross section, compared to the reflectarray designed by the conventional phase-only synthesis technique. [ABSTRACT FROM AUTHOR]

A colorimetric-electrochemical dual-mode analytical method based on bismuth metal-organic framework nanozyme was developed for label-free and trace/ultra-trace Cr6+ detection. 3D ball-flower shaped bismuth oxide formate (BiOCOOH) was used as the precursor and template to facilely construct the metal-organic framework nanozyme BiO-BDC-NH 2 , which possesses intrinsic peroxidase-mimic activity to effectively catalyze the colorless 3,3′,5,5′-tetramethylbenzidine into blue oxidation products in the presence of hydrogen peroxide. Based on Cr6+ to promote the peroxide-mimic activity of BiO-BDC-NH 2 nanozyme, a colorimetric method for Cr6+ detection was developed with the detection limit of 0.44 ng mL−1. Cr6+ can be electrochemically reduced to Cr3+ that would specifically inhibit the peroxidase-mimic activity of BiO-BDC-NH 2 nanozyme. Thus, the colorimetric system for Cr6+ detection was converted into a low-toxic and signal-off electrochemical sensor. The electrochemical model showed upgraded sensitivity and a lower detection limit of 9.00 pg mL−1. The dual-model method was developed for selective appropriate sensing instruments in different detection scenarios, which can provide built-in correction for environmental effects, as well as the development and utilization of dual-signal sensing platforms for trace to ultra-trace Cr6+ rapid assay. [Display omitted] • A bismuth-based MOF nanozyme with 3D ball-flower shape was constructed. • The MOF showed Cr6+-promoted and Cr3+-inhibited peroxidase-mimic activity. • A dual-model colorimetric-electrochemical sensor for trace to ultra-trace Cr6+ detection. • The colorimetric model can convert into sensitive electrochemical model. [ABSTRACT FROM AUTHOR]

In a double-well system, we investigate theoretically the population distribution of a particle perturbed by a weak sinusoidal signal with a Gaussian white noise accompanied. Our numerical simulation shows that the probability of the particle staying in the right potential well, PR, exhibits an extreme value at specific noise intensity D depending on the frequency of the sinusoidal signal, which is a key feature of stochastic resonance. This is confirmed by calculating the power spectrum of the output signal, in which the extreme value of the amplitude locates at the same noise intensity. These results provide us with a new way to quantify the stochastic resonance by measuring the population distribution of the particle. [ABSTRACT FROM AUTHOR]

The enantiomers of chiral alcohols with bulky groups are separated on the opposite sides of the Ti 6 cluster. [Display omitted] The conformational analysis of peripheral ligands on the polyoxotitanate has drawn much less attention than its application in photocatalysis. In this study, a series of polyoxotitanate clusters with the same Ti 6 kernels but different alcohol ligands have been synthesized and characterized. A systematic configurational analysis has revealed that when steric demanding enantiomeric alcohol ligands are confined within a narrow space as on the hexanuclear Ti 6 clusters, they can achieve regional separation on different sides of the clusters. [ABSTRACT FROM AUTHOR]

A heterogeneous photocatalytic 3-trifluoromethylation and 3-perfluoroalkylation of 4-aminocoumarins was realized from 4-aminocoumarins and CnF2n+1SO2Na under mild conditions using mesoporous graphitic carbon nitride (mpg-C3N4) as an effective and recyclable photocatalyst without any other additives. This transition-metal-free procedure shows wide substrate scope with air as a green oxidant affording 3-trifluoromethylated/perfluoroalkylated 4-aminocoumarins in moderate to good yields. [ABSTRACT FROM AUTHOR]

Accurately describing the knowledge dissemination process is significant to enhance the performance of personalized education. In this study, considering the effect of periodic teaching activities on the learning process, we propose a periodic impulsive knowledge dissemination system to regenerate the knowledge dissemination process. Meanwhile, we put forward learning effectiveness which is an outcome of a trade-off between the benefits and costs raised by knowledge dissemination as objective function. Further, we investigate the optimal teaching strategy which can maximize learning effectiveness, to obtain the optimal effect of knowledge dissemination affected by the teaching activities. We solve this dynamic optimization problem by optimal control theory and get the optimization system. At last we numerically solve this system in several practical examples to make the conclusions intuitive and specific. The optimal teaching strategy proposed in this paper can be applied widely in the optimization problem of personal education and beneficial for enhancing the effect of knowledge dissemination. [ABSTRACT FROM AUTHOR]

Vortex holes at the welding interface will affect the interface sealing performance of the explosive welding clad plate, so in the production process to choose the appropriate parameters to avoid the production of vortex holes. The step method is used to study the titanium-copper explosive welding clad plate interface vortex holes generation and interface ripple morphology change law under different stand-off distances. Experimental results show that the shear strength of the welding interface, the wavelength and amplitude of the ripple are positively correlated with the stand-off distance. The closer to the interface, the greater the hardness; the presence of dislodged metal blocks in the melt zone leads to no significant increase in hardness. When the stand-off distance is 4 mm ( β = 16 ∘ , V p = 779 m / s ), the least amount of intermetallic compounds is generated at the interface. When the stand-off distance is not more than 8 mm ( β ≤ 19 ∘ , V p ≤ 947 m / s ), there are no vortex holes on the interface. The welding process is simulated by the smooth particle hydrodynamics method in AUTODYN. The numerical simulation results show that the main component of the jet is titanium; numerical simulation can well predict the ripple shape of the welding interface. [ABSTRACT FROM AUTHOR]

Monitoring threatened species at the individual level is fundamental and crucial in ecology and conservation, especially for critically endangered species. Hainan gibbon (Nomasucs hainanus) is the world's rarest primate species with <40 individuals, urgently needs a labor-efficient and continuous individual-level monitoring system to inform science-based conservation actions. Male dispersal, replacement, and formation of new groups with females are crucial for the population dynamics of gibbons. Their loud and elaborate morning songs provide the potential to automate the monitoring of their dynamics. Based on acoustic recordings from focal recording and 13 autonomous recording units within gibbons' home ranges, we developed an automated system, which successively (a) detected song bouts (duration ≈ 10 min, with ≈ 50 phrases) with temporal parameters using an energy detector with a hidden Markov model (F1 score >75 %), (b) detected and classified phrases (duration ≈ 5 s) within song bouts using a random forest model (F1 score ≈ 80–90 %), and (c) classified known individuals by a linear support vector machine (accuracy >93 %), and recognized unknown individuals by Gaussian mixture models (accuracy >90 %). The system successfully monitored a male immigration and kept tracking a dispersing male for nearly a year since it left the natal group to establish its own group with two females. Our system is effective even in the face of an ever-changing population and can be applied to passive acoustic data. It will contribute to the realization of long-term, large-scale, and continuous monitoring of individual dynamics for vocal animals. • We identified and tracked the dispersal of male Hainan gibbons with an automated system. • The system needs little training data and is robust against data variations. • The system helps to monitor individual dynamics from passive acoustics continuously. [ABSTRACT FROM AUTHOR]

Mn-based superconductors are very rare and their superconductivity has only been reported in three-dimensional MnP and quasi-one-dimensional KMn6Bi5 and RbMn6Bi5 with [Mn6Bi5]âˆ' columns under high pressures. Here we report the synthesis, magnetism, electrical resistivity, and specific heat capacity of the newly discovered quasi-one-dimensional NaMn6Bi5. Compared with other A Mn6Bi5 (A = K, Rb, and Cs), NaMn6Bi5 has abnormal Bi-Bi bond lengths and two antiferromagnetic-like transitions at 47.3 K and 51.8 K. Anisotropic resistivity and low-temperature non-Fermi liquid behavior are observed. Heat capacity measurement reveals that the Sommerfeld coefficient for NaMn6Bi5 is unusually large. Using first-principles calculations, an unusual enhancement of density of states near the Fermi level is demonstrated for NaMn6Bi5. The features make NaMn6Bi5 a more suitable platform to explore the interplay of magnetism and superconductivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrogel has lower hardness and better safety. • HP-β-CD acts dual functions as hydrogel component and encapsulating resveratrol. • Hydrogel can increase anti-depressant effects of resveratrol. Thermosensitive Hydrogel System (THS) is a suitable candidate for targeted drug delivery, because of its intelligent response and controlled release. In this work, combination of guanidine-chitosan (GCS), β-glycerol phosphate disodium salt (β-GP) and hydroxypropyl-β-cyclodextrin (HP-β-CD) can successfully result in a novel THS by single factor and response surface method. The characterization of THS is detected with gelation temperature, FT-IR, SEM, in vitro release, rheology and biocompatibility. Resveratrol (Res) is selected as a model drug to evaluate the anti-depressant effects of THS loaded Res (Res-THS) via intranasal administration of chronic unpredictable mild stress (CUMS) rats. The results display that the Res-THS can increase concentration of neurotransmitter in rats' brain tissue via intranasal administration, indicating the anti-depressant effect. [ABSTRACT FROM AUTHOR]

A large number of natural and anthropogenic wastes were landfilled, and dissolved organic matter (DOM) were formed during landfill. However, the composition, transformation, and coexistence characteristics of natural and anthropogenic DOM in leachate remain unclear. Fourier transform ion cyclotron resonance mass spectrometry, size exclusion chromatography, gas chromatography coupled with mass spectrometry, and three-dimensional excitation-emission matrix spectrum were employed to clarify comprehensively the abovementioned question. The results showed that natural DOM in young leachate constituted mainly straight-chain organic acids, protein substances, and building blocks of humic substances (BB). Straight-chain organic acids vanished in old leachates, and the concentration of protein substances and BB decreased from 44% to 26% and from 47% to 12%, respectively, while CHON and CHONS were degraded to CHO and CHOS during the process. As to anthropogenic DOM, its types and relative content in leachate increased during landfill, and aromatic acids, terpenes, halogenated organics, indoles, and phenols became the main organic components in old leachate. Compared to natural DOM, anthropogenic DOM was degraded slowly and accumulated in leachate, and some of the natural DOM facilitated the dechlorination of dichlorinated organic compounds. This study demonstrates that landfill led to an increase in humic substances and halogenated organic compounds in old leachate, which was intensified with concentrated leachate recirculation. [Display omitted] • The young leachate comprised a large number of organic nitrogen. • The types and content of halogenated organic matter increased in leachate over time. • Lignin, tannin and monochlorinated organics were accumulated in the old leachate. • Low molecular natural dissolved organic matter aids the dechlorination of dichloride. [ABSTRACT FROM AUTHOR]

Background: Cryptosporidium is an important zoonotic pathogen responsible for severe enteric diseases in humans and animals. However, the molecular mechanisms underlying host and Cryptosporidium interactions are still not clear. Methods: To study the roles of circRNAs in host cells during Cryptosporidium infection, the expression profiles of circRNAs in HCT-8 cells infected with C. parvum were investigated using a microarray assay, and the regulatory role of a significantly upregulated circRNA, ciRS-7, was investigated during C. parvum infection. Results: C. parvum infection caused notable alterations in the expression profiles of circRNAs in HCT-8 cells, and a total of 178 (including 128 up- and 50 downregulated) circRNAs were significantly differentially expressed following C. parvum infection. Among them, ciRS-7 was significantly upregulated and regulated the NF-κB signaling pathway by sponging miR-1270 during C. parvum infection. Furthermore, the ciRS-7/miR-1270/relA axis markedly affected the propagation of C. parvum in HCT-8 cells. Conclusions: Our results revealed that ciRS-7 would promote C. parvum propagation by regulating the miR-1270/relA axis and affecting the NF-κB pathway. To the best of our knowledge, this is the first study to investigate the role of circRNA during Cryptosporidium infection, and the findings provide a novel view for implementing control strategies against Cryptosporidium infection. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disease in reproductive women, and the endocrine levels are also affected by diseases. The aim of this study was to determine the effect of thrombospondin-1 (TSP-1) on PCOS rat model. We established the PCOS rat model, the serum hormones including TSP-1 expression were determined and morphological characteristics were investigated to evaluate the model. These above endocrine and morphological features were investigated again to evaluate the effect of TSP-1 treatment. In the PCOS model group, the serum hormones change (higher luteinizing hormone, testosterone and estrogen) and decreased TSP-1 expression levels were found compared with the control group. Besides, the morphological characteristics of PCOS were also observed in the model group. After TSP-1 treatment, the higher TSP-1, ANGPT2, PDGFB and PDGFD expression levels, the lower LH and T levels, decreased vessel density as well as VEGFA and ANGPT1 expression levels were found compared with the control group, and the ovary morphological changes were also observed in the TSP-1 experimental group. TSP-1 delivery system might be an alternative therapy for PCOS treatment. [ABSTRACT FROM AUTHOR]

Abstract: A Nafion membrane with enhanced performance has been prepared by using a novel casting solution containing low-polarity nonsolvent tetrachloroethylene (TCE). TCE induces self-organization of the ionomer and turns the originally transparent Nafion in dimethylformamide (DMF) solution into opaque. The Nafion membrane cast from such opaque solution remains mechanically robust and shows a proton conductivity of 0.07 S cm−1 at room temperature, and 0.21 S cm−1 at 80 °C under saturated humidity, which is an increase of 62% and 103% respectively over the membrane without TCE involvement. Besides, water content and water permeability of the new membrane become higher. The enhanced membrane performance is attributed to larger clusters of sulfonate groups in Nafion, which is revealed by small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). [Copyright &y& Elsevier]