Cellular mechanism underlying leptin-induced anion secretion of rat epididymal epithelial cells.

BACKGROUND: A large number of studies have shown that leptin plays an important role in the regulation of fertility via the hypothalamus-pituitary-gonad axis. However, its peripheral function in epididymis was still elusive. OBJECTIVE: The purpose of this study was to determine the pro-secretion effect of leptin on the rat epididymal epithelium. MATERIALS AND METHODS: In the present study, real-time quantitative polymerase chain reaction, western blot, and immunohistochemical analysis were employed to detect the expression pattern of leptin receptors in rat epididymis. The pro-secretion effect of leptin on epididymal epithelial cells was measured by short-circuit current, and the prostaglandin E2 and cyclic adenosine monophosphate level was evaluated by enzyme-linked immunosorbent assay. RESULTS: We verified that the leptin receptor was located on the epididymal epithelium, with a relatively high expression level in corpus and cauda epididymis. Ussing chamber experiments showed that leptin stimulated a significant rise of the short-circuit current in rat epididymal epithelial cells, which could be abolished by the specific leptin receptor antagonist peptide Allo-aca, or by removing the ambient Cl- and HCO3 -. Furthermore, the leptin-stimulated short-circuit current response could be abrogated by blocking the apical cystic fibrosis transmembrane regulator or the basolateral Na+-K+-2Cl- cotransporter. Our pharmacological experiments manifested that interfering with the prostaglandin H synthase-2-prostaglandin E2-EP2/EP4-adenylate cyclase pathways could significantly blunt the cystic fibrosis transmembrane regulator-mediated anion secretion induced by leptin. The enzyme-linked immunosorbent assay demonstrated that leptin could induce a substantial increase in prostaglandin E2 release and cyclic adenosine monophosphate synthesis of primary cultured rat cauda epididymal epithelial cells. Our data also suggested that JAK2, ERK, and PI3K-dependent phosphorylation may be involved in the activation of prostaglandin H synthase-2 and the subsequent prostaglandin E2 production. CONCLUSIONS: The present study demonstrated the pro-secretion function of leptin in rat epididymal epithelium via the activation of cystic fibrosis transmembrane regulator and Na+-K+-2Cl- cotransporter, which was dependent on the paracrine/autocrine prostaglandin E2 stimulated EP2/EP4-adenylate cyclase pathways, and thus contributed to the formation of an appropriate microenvironment essential for sperm maturation.

Deep optimization of water quality index and positive matrix factorization models for water quality evaluation and pollution source apportionment using a random forest model.

Effective evaluation of water quality and accurate quantification of pollution sources are essential for the sustainable use of water resources. Although water quality index (WQI) and positive matrix factorization (PMF) models have been proven to be applicable for surface water quality assessments and pollution source apportionments, these models still have potential for further development in today's data-driven, rapidly evolving technological era. This study coupled a machine learning technique, the random forest model, with WQI and PMF models to enhance their ability to analyze water pollution issues. Monitoring data of 12 water quality indicators from six sites along the Minjiang River from 2015 to 2020 were used to build a WQI model for determining the spatiotemporal water quality characteristics. Then, coupled with the random forest model, the importance of 12 indicators relative to the WQI was assessed. The total phosphorus (TP), total nitrogen (TN), chemical oxygen demand (CODCr), dissolved oxygen (DO), and five-day biochemical oxygen demand (BOD5) were identified as the top five significant parameters influencing water quality in the region. The improved WQI model constructed based on key parameters enabled high-precision (R2 = 0.9696) water quality prediction. Furthermore, the feature importance of the indicators was used as weights to adjust the results of the PMF model, allowing for a more reasonable pollutant source apportionment and revealing potential driving factors of variations in water quality. The final contributions of pollution sources in descending order were agricultural activities (30.26%), domestic sewage (29.07%), industrial wastewater (26.25%), seasonal factors (6.45%), soil erosion (6.19%), and unidentified sources (1.78%). This study provides a new perspective for a comprehensive understanding of the water pollution characteristics of rivers, and offers valuable references for the development of targeted strategies for water quality improvement.

New insights into pollution source analysis using receptor models in the upper Yangtze river basin: Effects of land use on source identification and apportionment.

To effectively control pollution and improve water quality, it is essential to accurately analyze the potential pollution sources in rivers. The study proposes a hypothesis that land use can influence the identification and apportionment of pollution sources and tested it in two areas with different types of water pollution and land use. The redundancy analysis (RDA) results showed that the response mechanisms of water quality to land use differed among regions. In both regions, the results indicated that the water quality response relationship to land use provided important objective evidence for pollution source identification, and the RDA tool optimized the procedure of source analysis for receptor models. Positive matrix decomposition (PMF) and absolute principal component score-multiple linear regression (APCS-MLR) receptor models identified five and four pollution sources along with their corresponding characteristic parameters. PMF attributed agricultural nonpoint sources (23.8%) and domestic wastewater (32.7%) as the major sources in regions 1 and 2, respectively, while APCS-MLR identified mixed sources in both regions. In terms of model performance parameters, PMF demonstrated better-fit coefficients (R2) than APCS-MLR and had a lower error rate and proportion of unidentified sources. The results show that considering the effect of land use in the source analysis can overcome the subjectivity of the receptor model and improve the accuracy of pollution source identification and apportionment. The results of the study can help managers clarify the priorities of pollution prevention and control, and provide a new methodology for water environment management in similar watersheds.

Aerobic exercises regulate the epididymal anion homeostasis of high-fat diet-induced obese rats through TRPA1-mediated Cl- and HCO3- secretion†.

Aerobic exercises could improve the sperm motility of obese individuals. However, the underlying mechanism has not been fully elucidated, especially the possible involvement of the epididymis in which sperm acquire their fertilizing capacity. This study aims to investigate the benefit effect of aerobic exercises on the epididymal luminal milieu of obese rats. Sprague-Dawley male rats were fed on a normal or high-fat diet (HFD) for 10 weeks and then subjected to aerobic exercises for 12 weeks. We verified that TRPA1 was located in the epididymal epithelium. Notably, aerobic exercises reversed the downregulated TRPA1 in the epididymis of HFD-induced obese rats, thus improving sperm fertilizing capacity and Cl- concentration in epididymal milieu. Ussing chamber experiments showed that cinnamaldehyd (CIN), agonist of TRPA1, stimulated an increase of the short-circuit current (ISC) in rat cauda epididymal epithelium, which was subsequently abolished by removing the ambient Cl- and HCO3-. In vivo data revealed that aerobic exercises increased the CIN-stimulated Cl- secretion rate of epididymal epithelium in obese rats. Pharmacological experiments revealed that blocking cystic fibrosis transmembrane regulator (CFTR) and Ca2+-activated Cl- channel (CaCC) suppressed the CIN-stimulated anion secretion. Moreover, CIN application in rat cauda epididymal epithelial cells elevated intracellular Ca2+ level, and thus activate CACC. Interfering with the PGHS2-PGE2-EP2/EP4-cAMP pathway suppressed CFTR-mediated anion secretion. This study demonstrates that TRPA1 activation can stimulate anion secretion via CFTR and CaCC, which potentially forming an appropriate microenvironment essential for sperm maturation, and aerobic exercises can reverse the downregulation of TRPA1 in the epididymal epithelium of obese rats.

Exercise Reduces Airway Smooth Muscle Contraction in Asthmatic Rats via Inhibition of IL-4 Secretion and Store-Operated Ca2+ Entry Pathway.

PURPOSE: Increased evidence has shown that aerobic exercise reduces airway hyperresponsiveness in asthmatic individuals. However, the underlying mechanisms of action remain elusive. This study aimed to investigate the effect of exercise on airway smooth muscle (ASM) contractile function in asthmatic rats, and uncover the possible involvement of interleukin 4 (IL-4) and the store-operated Ca2+ entry (SOCE) pathway. METHODS: In this study, chicken ovalbumin was used to induce asthma in male Sprague-Dawley rats. The exercise group received moderate-intensity aerobic exercise training for 4 weeks. IL-4 concentrations in bronchoalveolar lavage fluid (BALF) samples were evaluated by enzyme linked immunosorbent assay. The contractile function of the ASM was investigated using tracheal ring tension experiments and intracellular Ca2+ imaging techniques. Western blot analysis was used to evaluate expression levels of calcium-release activated calcium (CRAC) channel protein (Orai) and stromal interaction molecule 1 (STIM1) in ASM. RESULTS: Our data showed that the carbachol-stimulated, SOCE-mediated contraction of rat ASM was significantly increased in asthmatic rats, which could be abolished by exercise. Pharmacological studies revealed that GSK5498A and BTP-2, selective blockers of CRAC channels significantly inhibited SOCE-induced ASM contraction. In addition, exercise inhibited the up-regulation of IL-4 in BALF as well as STIM1 and Orai expression in the ASM of asthmatic rats. In line with these observations, we demonstrated that pretreatment of the ASM with IL-4 up-regulated the expression level of STIM1, Orai1 and Orai2, thereby promoting SOCE-mediated ASM contraction. CONCLUSIONS: The data in this study reveal that aerobic exercise may improve the ASM contractile function in asthmatic rats by inhibiting IL-4 secretion and by down-regulating the expression of STIM1, Orai1 and Orai2, thus decreasing excessive SOCE-mediated ASM contraction in asthmatic rats.

Key Targets and Molecular Mechanisms of the Fat-soluble Components of Ginseng for Lung Cancer Treatment.

OBJECTIVE: To analyze the regulatory effects and key targets of the fat-soluble components of ginseng in lung cancer. METHODS: Gas chromatography-mass spectrometry and the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform were used to analyze and identify the fat-soluble components of ginseng. Network pharmacology was used to analyze the therapeutic targets of the fat-soluble components of ginseng in lung cancer and screen key proteins. In vitro assays were conducted to verify the effects of the active fat-soluble components of ginseng on proliferation and apoptosis in lung cancer cells and to verify the regulation of key proteins. RESULTS: Ten active fat-soluble components of ginseng were screened for follow-up. Network pharmacology showed 33 overlapping targets between the active fat-soluble components of ginseng and lung cancer, and functional enrichment of the targets showed involvement of response to nitrogen, hormone response, membrane raft, and positive regulation of external stimulus. Pathway enrichment analysis showed vascular endothelial growth factor (VEGF) signaling, adipocyte lipolysis regulation, chronic myelogenous leukemia, endocrine resistance, and NSCLC-related pathways. A protein-protein interaction network was constructed, and the top 10 targets were selected in accordance with their scores. Ultimately, five target genes (EGFR, KDR, MAPK3, PTPN11, and CTNNB1) were selected in combination with literature mining for subsequent experimental verification. Proliferation assays showed that the growth of lung cancer cells was significantly decreased in a concentration-dependent manner in the fat-soluble components of ginseng intervention group compared with controls. Flow cytometry showed that active fat-soluble components of ginseng promoted apoptosis in a concentration-dependent manner in lung cancer cells. Western blot and quantitative real-time PCR showed that levels of the five key proteins and mRNAs were significantly decreased in the intervention group; furthermore, histone protein and mRNA levels were significantly higher in the high-concentration intervention group compared with the low-concentration group. CONCLUSION: The active fat-soluble components of ginseng inhibited the growth of lung cancer cells and promoted apoptosis. The underlying regulatory mechanisms may be related to signaling pathways involving EGFR, KDR, MAPK3, PTPN11, and CTNNB1.

Water quality assessment and pollution source apportionment using multivariate statistical techniques: a case study of the Laixi River Basin, China.

Identifying potential sources of pollution in tributaries and determining their contribution rates are critical to the treatment of water pollution in main streams. In this paper, we conducted a multivariate statistical analysis on the water quality data of 12 parameters for 3 years (2018-2020) at six sampling sites in the Laixi River to qualitatively identify potential pollution sources and quantitatively calculate the contribution rates to reveal the tributaries' pollution status. Spatio-temporal cluster analysis (CA) divided 12 months into two parts, corresponding to the lightly polluted season (LPS) and highly polluted season (HPS), and six sampling sites were divided into two regions, corresponding to the lightly polluted region (LPR) and highly polluted region (HPR). Principal component analysis (PCA) was used to determine the potential sources of contamination, identifying four and three potential factors in the LPS and HPS, respectively. The absolute principal component score-multiple linear regression (APCS-MLR) receptor model quantitatively analyzed the contribution rates of identified pollution sources, and the importance of the different pollution sources in LPS can be ranked as domestic sewage and industrial wastewater and breeding pollution (33.80%) > soil weathering (29.02%) > agricultural activities (20.95%) > natural influence (13.03%). HPS can be classified as agricultural cultivation (41.23%), domestic sewage and industrial wastewater and animal waste (33.19%), and natural variations (21.43%). Four potential sources were identified in LPR ranked as rural domestic sewage (31.01%) > agricultural pollution (26.82%) > industrial effluents and free-range livestock and poultry pollution (25.13%) > natural influence (14.82%). Three identified latent pollution sources in HPR were municipal sewage and industrial effluents (37.96%) > agricultural nonpoint sources and livestock and poultry wastewater (33.55%) > natural sources (25.23%). Using multivariate statistical tools to identify and quantify potential pollution sources, managers may be able to enhance water quality in tributary watersheds and develop future management plans.

Water quality assessment and pollution source apportionment using multivariate statistical and PMF receptor modeling techniques in a sub-watershed of the upper Yangtze River, Southwest China.

Rapid industrial and agricultural development as well as urbanization affect the water environment significantly, especially in sub-watersheds where the contaminants/constituents present in the pollution sources are complex, and the flow is unstable. Water quality assessment and quantitative identification of pollution sources are the primary prerequisites for improving water management and quality. In this work, 168 water samples were collected from seven stations throughout 2018-2019 along the Laixi River, a vital pollution control unit in the upper reaches of the Yangtze River. Multivariate statistics and positive matrix factorization (PMF) receptor modeling techniques were used to evaluate the characteristics of the river-water quality and reveal the pollution sources. Principal component analysis was employed to screen the crucial parameters and establish an optimized water quality assessment procedure to reduce the analysis cost and improve the assessment efficiency. Cluster analysis further illustrates the spatiotemporal distribution characteristics of river-water quality. Results indicated that high-pollution areas are concentrated in the tributaries, and the high-pollution periods are the spring and winter, which verifies the reliability of the evaluation system. The PMF model identified five and six potential pollution sources in the cold and warm seasons, respectively. Among them, pollution from agricultural activities and domestic wastewater shows the highest contributions (33.2% and 30.3%, respectively) during the cold and warm seasons, respectively. The study can provide theoretical support for pollutant control and water quality improvement in the sub-watershed, avoiding the ecological and health risks caused by the deterioration of water quality.

Ecological risk assessment and identification of the distinct microbial groups in heavy metal-polluted river sediments.

To assess the health of river ecosystems, it is essential to quantify the ecological risk of heavy metals in river sediments and the structure of microbial communities. As important tributaries of the Tuo River in the upper reaches of the Yangtze River, the Mianyuan River and the Shiting River, are closely related to the economic development and human daily life in the region. This study assessed the ecological risks of heavy-metal-polluted river sediments, the heavy-metal-driven bacterial communities were revealed, and the relationships between the ecological risks and the identical bacterial communities were discussed. The Cd content was significantly greater than the environmental background value, leading to a serious pollution and very high ecological risk at the confluence of the two rivers and the upper reaches of the Mianyuan River. Microbial community analysis showed that Rhodobacter, Nocardioides, Sphingomonas, and Pseudarthrobacter were the dominant bacterial genera in the sediments of the Shiting River. However, the dominant bacterial genera in the Mianyuan River were Kouleothrix, Dechloromonas, Gaiella, Pedomicrobium, and Hyphomicrobium. Mantel test results showed (r = 0.5977, P = 0.005) that the Cd, As, Zn, Pb, Cr, and Cu were important factors that influenced differences in the distribution of sediment bacterial communities Mianyuan and Shiting rivers. A correlation heatmap showed that heavy metals were negatively correlated for most bacterial communities, but some bacterial communities were tolerant and showed a positive correlation. Overall, the microbial structure of the river sediments showed a diverse spatial distribution due to the influence of heavy metals. The results will improve the understanding of rivers contaminated by heavy metals and provide theoretical support for conservation and in situ ecological restoration of river ecosystems.

Toxoplasma gondii infection triggers ongoing inflammation mediated by increased intracellular Cl- concentration in airway epithelium.

Toxoplasma gondii is a widespread parasitic protozoan causing toxoplasmosis including pulmonary toxoplasmosis. As the first line of host defense, airway epithelial cells play critical roles in orchestrating pulmonary innate immunity. However, the mechanism underlying the airway inflammation induced by the T. gondii infection remains largely unclear. This study demonstrated that after infection with T. gondii, the major anion channel located in the apical membranes of airway epithelial cells, cystic fibrosis transmembrane conductance regulator (CFTR), was degraded by the parasite-secreted cysteine proteases. The intracellular Cl- concentration ([Cl-]i) was consequently elevated, leading to activation of nuclear factor-κB (NF-κB) signaling via serum/glucocorticoid regulated kinase 1. Furthermore, the heightened [Cl-]i and activated NF-κB signaling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP level through NF-κB-mediated up-regulation of phosphodiesterase 4. Conversely, the sulfur-containing compound allicin conferred anti-inflammatory effects on pulmonary toxoplasmosis by decreasing [Cl-]i via activation of CFTR. These results suggest that the intracellular Cl- dynamically modulated by T. gondii mediates sustained airway inflammation, which provides a potential therapeutic target against pulmonary toxoplasmosis.

The influence of benevolent leadership on knowledge sharing of postgraduate supervisor: A moderated mediating model.

In order to explore the mechanism and boundary conditions of the influence of benevolent leadership on knowledge sharing, we took postgraduate supervisor as participants and constructed a moderated mediating effect model. In this study, a total of 1,083 valid questionnaires were collected by questionnaire method and the confirmatory factor analysis, correlation analysis, regression analysis, and Hayes's PROCESS macro were used to analyze the data. The results show that benevolent leadership positively affects knowledge sharing. Creative self-efficacy mediates the relationship between benevolent leadership and knowledge sharing. Professional identity moderates the relationship between benevolent leadership and creative self-efficacy, when the professional identity is (M - 1 SD) and (M + 1 SD), the moderating effect is significant, while when the professional identity is (M), the moderating effect is not significant. Research stress moderates the relationship between creative self-efficacy and knowledge sharing, when research stress is (M - 1 SD), (M), and (M + 1 SD), the moderating effect is significant. Professional identity and research stress jointly moderated the mediating effect of creative self-efficacy. Professional identity moderated the first half path of the mediating model, while research stress moderated the second half path of the mediating model. When the level of professional identity is high and research stress is high, benevolent leadership has the greatest positive influence on knowledge sharing through creative self-efficacy. When the level of professional identity is low and research stress is high, benevolent leadership has the greatest negative influence on knowledge sharing through creative self-efficacy. This study enriches the relevant research on benevolent leadership and knowledge sharing, explores the conditions and factors that enhance or buffer benevolent leadership, and shows that the best effect can be achieved when the leadership behavior is consistent with the situational factors.

G protein-coupled estrogen receptor promotes acrosome reaction via regulation of Ca2+ signaling in mouse sperm†.

G protein-coupled estrogen receptor (GPER), a seven-transmembrane G protein-coupled receptor, mediates the rapid pre-genomic signaling actions of estrogen and derivatives thereof. The expression of GPER is extensive in mammal male reproductive system. However, the functional role of GPER in mouse sperm has not yet been well recognized. This study revealed that GPER was expressed at the acrosome and the mid-flagellum of the mouse sperm. The endogenous GPER ligand 17ß-estradiol and the selective GPER agonist G1 increased intracellular Ca2+ concentration ([Ca2+]i) in mouse sperm, which could be abolished by G15, an antagonist of GPER. In addition, the G1-stimulated Ca2+ response was attenuated by interference with the phospholipase C (PLC) signaling pathways or by blocking the cation channel of sperm (CatSper). Chlortetracycline staining assay showed that the activation of GPER increased the incidence of acrosome-reacted sperm. Conclusively, GPER was located at the acrosome and mid-flagellum of the mouse sperm. Activation of GPER triggered the elevation of [Ca2+]i through PLC-dependent Ca2+ mobilization and CatSper-mediated Ca2+ influx, which promoted the acrosome reaction of mouse sperm.

Distribution of sediment microbial communities and their relationship with surrounding environmental factors in a typical rural river, Southwest China.

With rapid urbanization and industrialization, rural rivers in China are facing deterioration in water quality and ecosystem health. Microorganisms living in river sediments are involved in biogeochemical processes, mineralization, and degradation of pollutants. Understanding bacterial community distribution in rural rivers could help evaluate the response of river ecosystems to environmental pollution and understand the river self-purification mechanism. In this study, the relationship between characteristics of sediment microbial communities and the surrounding environmental factors in a typical rural river was analyzed using 16S rRNA gene sequencing technology. The results showed that the dominant bacterial groups in the river sediment were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, Bacteroidetes, and Firmicutes, accounting for 83.61% of the total microbial load. Different areas have different sources of pollution which give rise to specific dominant bacteria. The upstream part of the river flows through an agricultural cultivation area where the dominant bacteria were norank_f_Gemmatimonadaceae, Haliangium, and Pseudolabrys, possessing obvious nitrogen- and phosphorus-metabolizing activities. The midstream section flows through an urban area where the dominant bacteria were Marmoricola, Nocardioides, Gaiella, Sphingomonas, norank_f_67-14, Subgroup_10, Agromyces, and Lysobacter, with strong metabolizing activity for toxic pollutants. The dominant bacteria in the downstream part were Clostridium_sensu_stricto_1, norank_f__Bacteroidetes_vadinHA17, Candidatus_Competibacter, and Methylocystis. Redundancy analysis and correlation heatmap analysis showed that environmental factors: ammonia nitrogen (NH4+-N) and total nitrogen (TN) in the sediment, and pH, temperature, TN, electrical conductivity (EC), and total dissolved solids (TDS) in the water, significantly affected the bacterial community in the sediment. The PICRUSt2 functional prediction analysis identified that the main function of bacteria in the sediment was metabolism (77.3%), specifically carbohydrate, amino acid, and energy metabolism. These activities are important for degrading organic matter and removing pollutants from the sediments. The study revealed the influence of organic pollutants derived from human activities on the bacterial community composition in the river sediments. It gave a new insight into the relationship between environmental factors and bacterial community distribution in rural watershed ecosystems, providing a theoretical basis for self-purification and bioremediation of rural rivers.

Developing G value as an indicator for assessing the molecular status of immobilized antibody.

Antibody-functionalized nanoparticles (Ab-NPs) are widely used in bioassays due to their excellent affinity, specificity toward antigen, and ease of operation. However, the uncontrollable molecular status of antibodies on NPs severely limits their applications. This work aims at developing a simple method to evaluate the antigen-binding activity of Ab-NPs using two parameters, i.e., antibody adsorption amount and antigen-binding strength. Herein, we proposed a mathematical expression, G, to quantitively describe the amount and strength of Ab-NPs. G value could be used to assess the antigen-binding performance of NPs influenced by surface and solution factors. Seven types of polymers with different surface properties, including four positively and three negatively charged polymer brushes, were grown from silica NPs via surface-initiated atom transfer radical polymerization (SI-ATRP). A pair of antigen and antibody, human chorionic gonadotropin (hCG) and anti-hCG, were selected to screen the antibody immobilization property of polymer brushes. Among them, the G values of 2 polymer-NPs with opposite charges reached maximum, resulting in low detection limits for hCG, where pDMAEA-NP and pMMA-NP represent Poly[N,N-(dimethylamino)ethyl acrylate]-NP and poly(methyl methacrylate)-NP, respectively. The G value of Ab-NPs makes it feasible to estimate the molecular status of the adsorbed antibodies on surfaces, thus showing great potential for in vitro biosensing and bioseparation.

Laser-sintering fabrication of integrated Al/Ni anodes for lithium-ion batteries.

Integrated Al/Ni electrodes of lithium-ion batteries (LIBs) with variant atomic ratios were successfully fabricated by a one-step laser-sintering process. The microstructure, phase composition, and pore structure were controlled by the raw material composition and laser parameters. The electrodes showed working merits without any conductive agent and binder, or even the collector used in a traditional battery. It was shown that the electrode consisted of multi-phases, i.e., Al, Al3Ni2, Al3Ni, and Ni, when the Al/Ni atomic ratio was higher than 5 : 5. A lower Al/Ni atomic ratio less than 5 : 5 favored the formation of a dual-phase electrode consisting of Al3Ni2 and Ni. As the Al content increased, the specific surface area of the as-sintered electrodes increased in the initial stage and then decreased. The formation of pores was closely related to the content of the residual Al phase after the laser sintering. The residual Al phase filled the pores when the Al content was high, leading to a lower pore size. In contrast, the liquid Al phase completely reacted with the Ni component, leaving a large number of pores at its original sites. The linked pores can serve as transport channels for Li+ ions, provide mass sites for electrochemical reactions, and also buffer huge volume changes of the active material. Among the electrodes, the one with an Al/Ni ratio of 3 : 7 showed the best cycling/rate performance, i.e., a capacity of 522.8 mA h g-1 by a current of 0.1 A g-1 after 200 cycles, even holding to 338.4 mA h g-1 by a big current impact at 2 A g-1. It formed a metallurgical combination between the conductive network and the active material with multiple porous structures, which is helpful for the electrodes to provide high capacity and maintain structural stability during cycling. In addition, the average laser-sintering time of a single electrode was within 10 s, which is suitable for industrial mass production.

Influence of Work-Family Conflict on Turnover Intention of Primary and Secondary School Teachers: Serial Mediating Role of Psychological Contract and Job Satisfaction.

Objective: Based on conservation of resource theory and social exchange theory, to explore how work-family conflict can directly and indirectly influence turnover intention, with psychological contract and job satisfaction as a mediator. Methods: A total of 505 valid data were collected on primary and secondary school teachers by using work-family conflict questionnaire, turnover intention questionnaire, psychological contract questionnaire and job satisfaction questionnaire from 3 provinces in China. Confirmatory factor analysis was used to evaluate the discriminant validity and common method bias between the four variables through AOMS, the PROCESS macro for SPSS (Model 4 and Model 6) were applied to examine the mediating effect of psychological contract and job satisfaction. Results: Work-family conflict showed a direct and positive influence on turnover intention; psychological contract was shown to play a mediating role between work-family conflict and turnover intention; job satisfaction was shown to play a mediating role between work-family conflict and turnover intention; and psychological contract and job satisfaction was shown to play a serial mediating role between work-family conflict and turnover intention. Conclusion: Work-family conflict of primary and secondary school teachers will directly lead to turnover intention. Psychological contract and job satisfaction can reduce the positive influence of work-family conflict on turnover intention. School administrators should help teachers reduce work-family conflict and take effective measures to improve psychological contract and job satisfaction, so as to reduce turnover intention.

Mechanosensitive Piezo1 channel in rat epididymal epithelial cells promotes transepithelial K+ secretion.

The Piezo1 channel, a mechanosensitive channel that exhibit a preference for Ca2+, play multifarious physiological and pathological roles in the endothelium and epithelium of various tissues. However, the functional expression of Piezo1 channel in the epithelium of the male reproductive tract remains unknown. In the present study, the expression of Piezo1 channel in the rat epididymis was determined by real-time quantitative PCR, western blot and immunohistochemical analysis. Our data revealed that Piezo1 channel was located in the epithelial layer of the rat epididymis, with higher expression levels in the corpus and cauda regions. The pro-secretion function of Piezo1 channel was then investigated using short circuit current (ISC) and intracellular Ca2+ imaging techniques. Application of Yoda1, a selective Piezo1 channel activator, stimulated a remarkable decrease in the ISC of the epididymal epithelium. Pharmacological experiments revealed that the ISC response induced by Piezo1 channel activation was abolished by pretreating epithelial cells with the Yoda1 analogue, Dooku1, the selective mechanosensitive cation channel blocker, GsMTx4, or removal of basolateral K+. Meanwhile, we demonstrated that activation of Piezo1 channel triggered a robust Ca2+ influx in epididymal epithelial cells. The possible involvement of Ca2+- activated K+channels (KCa) in transepithelial K+ secretion was then evaluated. And that big conductance KCa (BK), but not small conductance or intermediate conductance KCa, mediated Piezo1-elicited transepithelial K+ secretion. Moreover, we demonstrated that NKCC and NKA were responsible for supplying substrate K+ during transepithelial K+ secretion. These data demonstrate that the activation of Piezo1 channel promotes BK-mediated transepithelial K+ secretion, and thus may plays an important role in the formation of a high K+ concentration in epididymal intraluminal fluid.

Activation of TRPV4 stimulates transepithelial K+ secretion in rat epididymal epithelium.

The maturation of sperms is dependent on the coordinated interactions between sperm and the unique epididymal luminal milieu, which is characterized by high K+ content. This study investigated the involvement of transient receptor potential vanilloid 4 (TRPV4) in the K+ secretion of epididymal epithelium. The expression level and cellular localization of TRPV4 and Ca2+-activated K+ channels (KCa) were analyzed via RT-PCR, real-time quantitative PCR, western blot and immunofluorescence. The functional role of TRPV4 was investigated using short-circuit current (ISC) and intracellular Ca2+ imaging techniques. We found a predominant expression of TRPV4 in the corpus and cauda epididymal epithelium. Activation of TRPV4 with a selective agonist, GSK1016790A, stimulated a transient decrease in the ISC of the epididymal epithelium. The ISC response was abolished by either the TRPV4 antagonists, HC067047 and RN-1734, or the removal of basolateral K+. Simultaneously, the application of GSK1016790A triggered Ca2+ influx in epididymal epithelial cells. Our data also indicated that the big conductance KCa (BK), small conductance KCa (SK) and intermediate conductance KCa (IK) were all expressed in rat epididymis. Pharmacological studies revealed that BK, but not SK and IK, mediated TRPV4-elicited transepithelial K+ secretion. Finally, we demonstrated that TRPV4 and BK were localized in the epididymal epithelium, which showed an increased expression level from caput to cauda regions of rat epididymis. This study implicates that TRPV4 plays an important role in the formation of high K+ concentration in epididymal intraluminal fluid via promoting transepithelial K+ secretion mediated by BK.

Source identification of surface water pollution using multivariate statistics combined with physicochemical and socioeconomic parameters.

Accurate identification of potential contamination sources of river water is a basis for effective pollution control and sustainable water management. Pollution source identification based on physicochemical-parameters-only method may lead to uncertainty and subjectivity. In this study along with hydrochemistry parameters (HPs), socioeconomic parameters (SPs) were considered as an auxiliary in multivariate statistics to achieve a comprehensive assessment on pollution sources with accurate estimates of source identification and apportionment. Fifteen physicochemical parameters were combined with twelve socioeconomic parameters in multivariate statistics to quantitatively assess potential pollution sources and their contributions to river water pollution. Multivariate statistics in the study included regression analysis, principal component analysis (PCA), and absolute principal component score-multiple linear regression (APCS-MLR). Regression analysis between hydro-chemical parameters and socioeconomic parameters indicated that industrial and population growths were the main factors related to ammonium nitrogen (NH4+-N), total nitrogen (TN) contamination, while total phosphorus (TP) was more correlated with domestic discharge and poultry breeding. Based on the results of PCA, four latent factors were extracted for hydrochemistry parameters (HPs) and socioeconomics parameters (SPs), accounting for 68.59% and 82.40% of the total variance, respectively. With integrating the PCA results of the two parameter groups, pollution sources were ranked as industrial effluents > rural wastewater > municipal sewage > phytoplankton growth and agricultural cultivation. Source apportionment in APCS-MLR revealed that industrial wastewater and rural wastewater averagely contributed 35.68% and 25.08% of pollution, respectively, followed by municipal sewage (18.73%) and phytoplankton pollution (15.13%) with relatively small percentage of unrecognized source. It is concluded that socioeconomic parameters assisting hydrochemistry parameters in multivariate statistics can improve the accuracy and certainty of pollution source identification, supporting decision makers to formulate strategies on protection of river water quality.

Versatile, Oxygen-Insensitive Surface-Initiated Anionic Polymerization to Prepare Functional Polymer Brushes in Aqueous Solutions.

Surface-initiated polymerization is an attractive approach to achieve desired interfacial compositions and properties on a wide range of substrates and surfaces. Due to mild reaction conditions, multiple surface-initiated polymerization methods, such as atom-transfer radical polymerization (ATRP), reversible addition-fragmentation chain-transfer polymerization, and so forth, have been developed and studied in academia and industry. However, the current methods require the combination of metal catalysts, special initiators, and oxygen removal. Herein, we developed a surface-initiated carbanion-mediated anionic polymerization (SI-CMAP), which can be conducted in aqueous solutions in the presence of oxygen without the need for metal catalysts. Zwitterionic 2-(N-3-sulfopropyl-N,N-dimethyl ammonium)ethyl methacrylate (SBMA) was selected as a model monomer to develop and demonstrate this strategy. The vinyl sulfone (VS) groups displayed on substrate surfaces reacted with N-methylimidazole (NMIM), which was used as the in situ initiator. The polymerization mechanism was extensively studied from many aspects at room temperature, including the changes in reaction conditions, factors affecting the polymerization extent, and substrate surfaces. We also demonstrated the compatibility of this method with a broad spectrum of monomers ranging from SBMA to other acrylates and acrylamides by using glycine betaine as a reaction additive. This method was also evaluated for the preparation of polymer-coated nanoparticles. For polymer-coated silica nanoparticles, their hydrodynamic diameter, copper contamination, and effects of salt and protein concentrations were compared with SI-ATRP in parallel. SI-CMAP in aqueous solutions in air and the absence of metal catalysts make this method sustainable and cost-effective. We believe that SI-CMAP can be readily adapted to the industrial surface coating and large-scale nanoparticle preparation under mild conditions.