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Calcitriol induces post-thawed bovine sperm capacitation
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作者 ANA CECILIA LIAUDAT FRANCISCA EBEL +4 位作者 BIANCA ANA OPIZZO MARINA AURORA GONZALEZ DAMIÁN BLOIS PABLO BOSCH NANCY RODRIGUEZ 《BIOCELL》 SCIE 2023年第5期1135-1143,共9页
Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D... Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D hypercalcemic metabolite,is related to human sperm motility,capacitation,and acrosome reaction.This work aimed to study the effect of calcitriol on bull sperm quality parameters and capacitation.Methods:One million freezethawed spermatozoa were obtained from different bulls and treated with 20 nM of calcitriol for 30 min.Untreated cells(negative control)and treated ones with calcitriol or heparin(100μg/mL,positive capacitation control)were evaluated for motility,viability,and functional parameters.Menadione(70μM,30 min)treatment was included as a reactive oxygen species(ROS)positive sperm agent.Results:The results elucidated that sperm exposed to 20 nM calcitriol showed higher viability,vigor,and capacitation than their positive and negative controls.The percentage of sperm with intact plasma and acrosome membranes,mitochondrial membrane potential(ΔΨm),and phosphatidylserine externalization was similar in all the conditions evaluated,while ROS production was higher with heparin and menadione-treated groups than the calcitriol group or negative control.Conclusion:Our results indicate that calcitriol induces the capacitation of thawed bull spermatozoa and maintains acceptable values of progressive motility,viability,and vigor without altering key biological parameters such as redox status,ΔΨm,and cell death. 展开更多
关键词 BOVINE Sperm capacitation CALCITRIOL Cell viability Plasma membrane integrity Reactive oxygen species
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Effects of Different Bovine Sperm Capacitation Methods on Fertilization in vitro 被引量:4
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作者 佟桂芝 韩永胜 +1 位作者 宋斌 王洪宝 《Agricultural Science & Technology》 CAS 2017年第5期846-847,共2页
In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed: two-time centrifugation (C)... In order to improve the in vitro fertilization rate of bovine, the effects of different sperm capacitation methods on fertilization were investigated. Total two treatments were designed: two-time centrifugation (C), and one-time centrifugation and swim-up method (CS). The results showed that the cleavage rate in the C treatment group was (75.6±4.5)%, which showed no difference compared with that ((76.4±1.9)%) in the CS treatment group (P〉0.05); there was also no significant dif- ference in blastocyst rate between the two treatment groups ((35.7±4.1)% vs. (36.3± 2.7)%, P〉0.05). However, the CS treatment significantly saved the capacitation time in vitro. 展开更多
关键词 capacitation method CENTRIFUGATION Swim-up method Ovary ot carcass Cleavage rate Blastocyst rate
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NYD-SP27,a novel intrinsic decapacitation factor in sperm 被引量:9
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作者 Ye Bi Wen-Ming Xu +4 位作者 Hau Yan Wong Hui Zhu Zuo-Min Zhou Hsiao Chang Chan Jia-Hao Sha 《Asian Journal of Andrology》 SCIE CAS CSCD 2009年第2期229-239,共11页
Prior to fertilization sperm has to undergo an activation process known as capaciation,leading to the acrosome reaction.Till now,little is known about the mechanism for preventing premature capacitation in sperm altho... Prior to fertilization sperm has to undergo an activation process known as capaciation,leading to the acrosome reaction.Till now,little is known about the mechanism for preventing premature capacitation in sperm although decapacitation factors from various sources have been thought to be involved.In this study,we report that NYD-SP27,an isoform of phospholipase C Zeta 1(PLCZ1),is localized to the sperm acrosome in mouse and human spermatozoa by immunofluorescence using a specific antibody.Western blot and double staining analyses show NYD-SP27 becomes detached from sperm,as they undergo capacitation and acrosome reaction.The absence of HCO_(3)^(-),a key factor in activating capacitation,from the capacitation-inducing medium prevents the loss of NYD-SP27 from sperm.The anti-NYD-SP27 antibody also prevents the loss of NYD-SP27 from sperm,reduced the number of capacitated sperm,inhibited the acrosome reaction induced by ATP and progesterone,and inhibited agonist-induced PLC-coupled Ca^(2+)mobilization in sperm,which can be mimicked by the PLC inhibitor,U73122.These data strongly suggest that NYD-SP27 is a physiological inhibitor of PLC that acts as an intrinsic decapacitation factor in sperm to prevent premature capacitation and acrosome reaction. 展开更多
关键词 acrosome reaction capacitation decapacitation factor NYD-SP27 phospholipase C
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Mechanism of sperm capacitation and the acrosome reaction: role of protein kinases 被引量:18
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作者 Debby Ickowicz Maya Finkelstein Haim Breitbart 《Asian Journal of Andrology》 SCIE CAS CSCD 2012年第6期816-821,共6页
Mammalian sperm must undergo a series of biochemical and physiological modifications, collectively called capacitation, in the female reproductive tract prior to the acrosome reaction (AR). The mechanisms of these m... Mammalian sperm must undergo a series of biochemical and physiological modifications, collectively called capacitation, in the female reproductive tract prior to the acrosome reaction (AR). The mechanisms of these modifications are not well characterized though protein kinases were shown to be involved in the regulation of intracellular Ca2+ during both capacitation and the AR. In the present review, we summarize some of the signaling events that are involved in capacitation. During the capacitation process, phosphatidyl-inositol-3-kinase (PI3K) is phosphorylated/activated via a protein kinase A (PKA)-dependent cascade, and downregulated by protein kinase C a (PKCa). PKCa is active at the beginning of capacitation, resulting in PI3K inactivation. During capacitation, PKCa as well as PP172 is degraded by a PKA-dependent mechanism, allowing the activation of PI3K. The activation of PKA during capacitation depends mainly on cyclic adenosine monophosphate (cAMP) produced by the bicarbonate-dependent soluble adenylyl cyclase. This activation of PKA leads to an increase in actin polymerization, an essential process for the development of hyperactivated motility, which is necessary for successful fertilization. Actin polymerization is mediated by PIP2 in two ways: first, PIP2 acts as a cofactor for phospholipase D (PLD) activation, and second, as a molecule that binds and inhibits actin-severing proteins such as gelsolin. Tyrosine phosphorylation of gelsolin during capacitation by Src family kinase (SFK) is also important for its inactivation. Prior to the AR, gelsolin is released from PIP2 and undergoes dephosphorylation/activation, resulting in fast F-actin depolymerization, leading to the AR. 展开更多
关键词 sperm capacitation acrosome reaction AR PKCΑ PI3K PKA GELSOLIN PIP2
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The role of ezrin-associated protein network in human sperm capacitation 被引量:4
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作者 Lei Wang Wen Chen +7 位作者 Chun Zhao Ran Huo Xue-Jiang Guo Min Lin Xiao-Yan Huang Yun-Dong Mao Zuo-Min Zhou Jia-Hao Sha 《Asian Journal of Andrology》 SCIE CAS CSCD 2010年第5期667-676,共10页
Membrane modifications in sperm cells represent a key step in sperm capacitation; however, the molecular basis of these modifications is not fully understood. Ezrin is the best-studied member of the ezrin/radixin/merl... Membrane modifications in sperm cells represent a key step in sperm capacitation; however, the molecular basis of these modifications is not fully understood. Ezrin is the best-studied member of the ezrin/radixin/merlin family. As a cross-linker between the cortical cytoskeleton and plasma membrane proteins, ezrin contributes to remodeling of the membrane surface structure. Furthermore, activated ezrin and the Rho dissociation inhibitor, RhoGDI, promote the formation of cortical cytoskeleton-polymerized actin through Rho activation. Thus, ezrin, actin, RhoGDI, Rho and plasma membrane proteins form a complicated network in vivo, which contributes to the assembly of the structure of the membrane surface. Previously, we showed that ezrin and RhoGDI1 are expressed in human testes. Thus, we sought to determine whether the ezrin-RhoGDIl-actin-membrane protein network has a role in human sperm capacitation. Our results by Western blot indicate that ezrin is activated by phosphorylation of the threonine567 residue during capacitation. Co-immunoprecipitation studies revealed that, during sperm capacitation, the interaction between ezrin and RhoGDI1 increases, and phosphostaining of two dimensional electrophoresis gels showed that RhoGDI 1 is phosphorylated, suggesting that RhoGDI 1 dissociates from RhoA and leads to actin polymerization on the sperm head. We speculate that activated ezrin interacts with polymerized actin and the glycosylated membrane protein cd44 after capacitation. Blocking sperm capacitation using ezrin- or actin-specific monoclonal antibodies decreases their acrosome reaction (AR) rate, but has no effect on the AR alone. Taken together, our results show that a network consisting of ezrin, RhoGDI1, RhoA, F-actin and membrane proteins functions to influence the modifications that occur on the membrane of the sperm head during human sperm capacitation. 展开更多
关键词 EZRIN MEMBRANE sperm capacitation
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Protein tyrosine phosphorylation of the human sperm head during capacitation: immunolocalization and relationship with acquisition of sperm-fertilizing ability 被引量:1
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作者 Arcangelo Barbonetti Maria Rosaria C. Vassallo +6 位作者 Giuliana Cordeschi Dimitrios Venetis Andrea Carboni Alessandra Sperandio Giorgio Felzani Sandro Francavilla Felice Francavilla 《Asian Journal of Andrology》 SCIE CAS CSCD 2010年第6期853-861,共9页
The occurrence of tyrosine phosphorylation (TP) in the sperm head during capacitation has been poorly investigated, and no data exist on the relationship of its dynamics with the acquisition of sperm fertilizing abi... The occurrence of tyrosine phosphorylation (TP) in the sperm head during capacitation has been poorly investigated, and no data exist on the relationship of its dynamics with the acquisition of sperm fertilizing ability. This study localized TP of head proteins in human spermatozoa during capacitation and explored its relationship with acquisition of the ability to display progesterone (P)-stimulated acrosome reactions (ARs) and to penetrate zona-free hamster oocytes. By immunofluorescence, TP immunoreactivity was revealed in the acrosomal region of formaldehyde-fixed/unpermeabilized samples, whereas it was abolished in fixed/permeabilized samples, in which TP immunoreactivity was high in the principal piece. No TP immunoreaetivity was detectable in unfixed spermatozoa. Head TP immunoreactivity was localized externally to the acrosome, close to the cytoplasmic membrane, as assessed by transmission electron microscopy. The increase in head TP was an early event during capacitation, occurring within 1 h in capacitating conditions. At this time, the P-stimulated ARs were also increased, whereas egg penetration was as poor as in uncapacitated spermatozoa. At 5 h of capacitation, the extent of neither head TP nor the P-induced ARs were greater than that at 1 h, whereas egg penetration had significantly increased. Seminal plasma inhibited head TP, P-induced ARs and egg penetration. None of these inhibitory effects, unlike those on tail TP, were prevented by the cAMP analogue dbcAMP (N,2-O-dibutyryladenosine 3',5'-cyclic monophosphate). In conclusion, head TP is a subsurface event occurring early during capacitation and is closely related to acquisition of the ability to display P-stimulated ARs, whereas the ability to fuse with oolemma and to decondense is a later capacitation-related event. 展开更多
关键词 acrosome reaction capacitation human spermatozoa sperm-oocyte fusion tyrosine phosphorylation
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Role of ions and ion channels in capacitation and acrosome reaction of spermatozoa
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作者 Sharad B Purohit Malini Laloraya G.Pradeep Kumar 《Asian Journal of Andrology》 SCIE CAS CSCD 1999年第3期95-107,共13页
Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of bindi... Capacitation and acrosome reaction are important prerequisites of the fertilization process. Capacitation is a highlycomplex phenomenon occurring in the female genital tract, rendering the spermatozoa capable of binding and fusionwith the oocyte. During capacitation various biochemical and biophysical changes occur in the spermatozoa and thespermatozoal membranes. Ions and ion channels also play important roles in governing the process of capacitation bychanging the fluxes of different ions which in turn controls various characteristics of capacitated spermatozoa. Alongwith the mobilization of ions the generation of free radicals and efflux of cholesterol also plays an important role in thecapacitation state of the spermatozoa. The generation of free radical and efflux of cholesterol change the mechano-dynamic properties of the membrane by oxidation of the polyunsaturated lipids and by generating the cholesterol freepatches. The process of capacitation renders the spermatozoa responsive to the inducers of the acrosome reaction. Theglycoprotein zona pellucida 3 (ZP3) of the egg coat zona pellucida is the potent physiological stimulator of the acro-some reaction; progesterone, a major compoent of the follicular fluid, is also an induce of the acrosome reaction.The inducers of the acrosome reaction cause the activation of the various ion-channels leading to high influxes of calci-um, sodium and bicarbonate. The efflux of cholesterol during the process of capacitation alters the permeablity of themembrane to the ions and generate areas which are prone to fusion and vesculation process during the acrosome reac-tion. Ths review focuses mainly on effects of the ion and ion-channels, free radicals, and membrane fluidity changesduring the process of capacitation and acrosome reaction. (Asian J Androl 1999 Sep; 1: 95-107) 展开更多
关键词 SPERMATOZOA capacitation acrosome reaction ion channels free radicals membrane fluidity
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Changes of Con A Receptor Sites on Mammalian Sperms during Capacitation and Acrosome Reaction
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作者 段崇文 陈大元 《Developmental and Reproductive Biology》 1994年第2期1-6,T001,共7页
No Con A receptor site was found on the intact plasma membranes of mammalian sperms before capacitation.After capacitation, however, the plasma membranes sloughed off, exposing the outer acrosomal membrane which is ri... No Con A receptor site was found on the intact plasma membranes of mammalian sperms before capacitation.After capacitation, however, the plasma membranes sloughed off, exposing the outer acrosomal membrane which is rich in Con A receptor sites.The vesicles formed during acrosome reaction were also found to bc rich in Con A receptor sites, suggesting their origin from outer acrosomal membranes.With completion of acrosome reaction, only inner acrosomal membrane was left in which no Con A receptor sites could be demonstrated.Also no Con A receptor site was found on egg plasma membrane throughout fertilization.It was thus shown that different membranes possess different properties. 展开更多
关键词 capacitation Acrosome reaction Con A receptor sites
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Decreased AKAP4/PKA signaling pathway in high DFI sperm affects sperm capacitation
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作者 Kun Zhang Xiu-Hua Xu +4 位作者 Jian Wu Ning Wang Gang Li Gui-Min Hao Jin-Feng Cao 《Asian Journal of Andrology》 SCIE CAS CSCD 2024年第1期25-33,共9页
The sperm DNA fragmentation index(DFI)is a metric used to assess DNA fragmentation within sperm.During in vitro fertilizationembryo transfer(IVF-ET),high sperm DFI can lead to a low fertilization rate,poor embryo deve... The sperm DNA fragmentation index(DFI)is a metric used to assess DNA fragmentation within sperm.During in vitro fertilizationembryo transfer(IVF-ET),high sperm DFI can lead to a low fertilization rate,poor embryo development,early miscarriage,etc.A kinase anchoring protein(AKAP)is a scaffold protein that can bind protein kinase A(PKA)to subcellular sites of specific substrates and protects the biophosphorylation reaction.Sperm protein antigen 17(SPA17)can also bind to AKAP.This study intends to explore the reason for the decreased fertilization rate observed in high sperm DFI(H-DFI)patients during IVF-ET.In addition,the study investigates the expression of AKAP,protein kinase A regulatory subunit(PKARIl),and SPA17 between H-DFI and low sperm DFI(L-DFI)patients.SPA17 at the transcriptional level is abnormal,the translational level increases in H-DFI patients,and the expression of AKAP4/PKARIl protein decreases.H,O,has been used to simulate oxidative stress damage to spermatozoa during the formation of sperm DFI.It indicates that H,O,increases the expression of sperm SPA17 protein and suppresses AKAP4/PKARIl protein expression.These processes inhibit sperm capacitation and reduce acrosomal reactions.Embryo culture data and IVF outcomes have been documented.The H-DFI group has a lower fertilization rate.Therefore,the results indicate that the possible causes for the decreased fertilization rate in the H-DFI patients have included loss of sperm AKAP4/PKARIl proteins,blocked sperm capacitation,and reduced occurrence of acrosome reaction. 展开更多
关键词 AKAP PKA SPA17 sperm capacitation sperm DNA fragmentation index
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Are sperm capacitation and apoptosis the opposite ends of a continuum driven by oxidative stress? 被引量:8
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作者 Robert J Aitken Mark A Baker Brett Nixon 《Asian Journal of Andrology》 SCIE CAS CSCD 2015年第4期633-639,共7页
This chapter explores the possibility that capacitation and apoptosis are linked processes joined by their common dependence on the continued generation of reactive oxygen species (ROS). According to this model capa... This chapter explores the possibility that capacitation and apoptosis are linked processes joined by their common dependence on the continued generation of reactive oxygen species (ROS). According to this model capacitation is initiated in spematozoa following their release into the female reproductive tract as a consequence of intracellular ROS generation, which stimulates intracellular cAMP generation, inhibits tyrosine phosphatase activity and enhances the formation of oxysterols prior to their removal from the sperm surface by albumin. The continued generation of ROS by capacitating populations of spermatozoa eventually overwhelms the limited capacity of these cells to protect themselves from oxidative stress. As a result the over-capacitation of spermatozoa leads to a state of senescence and the activation of a truncated intrinsic apoptotic cascade characterized by enhanced mitochondrial RO$ generation, lipid peroxidation, motility loss, caspase activation and phosphatidylserine externalization. The latter may be particularly important in instructing phagocytic leukocytes that the removal of senescent, moribund spermatozoa should be a silent process unaccompanied by the generation of proinflammatory cytokines. These observations reveal the central role played by redox chemistry in defining the life and death of spermatozoa. A knowledge of these mechanisms may help us to engineer novel solutions to both support and preserve the functionality of these highly specialized cells. 展开更多
关键词 APOPTOSIS reactive oxygen species sperm capacitation
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An epididymis-specific carboxyl esterase CES5A is required for sperm capacitation and male fertility in the rat 被引量:3
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作者 Yan-Fei Ru Hai-Min Xue +3 位作者 Zi-Mei Ni Dong Xia Yu-Chuan Zhou Yong-Lian Zhang 《Asian Journal of Andrology》 SCIE CAS CSCD 2015年第2期292-297,I0010,I0011,共8页
Despite the fact that the phenomenon of capacitation was discovered over half century ago and much progress has been made in identifying sperm events involved in capacitation, few specific molecules of epididymal orig... Despite the fact that the phenomenon of capacitation was discovered over half century ago and much progress has been made in identifying sperm events involved in capacitation, few specific molecules of epididymal origin have been identified as being directly involved in this process in vivo. Previously, our group cloned and characterized a carboxyl esterase gene CesSa in the rat epididymis. The CES5A protein is mainly expressed in the corpus and cauda epididymidis and secreted into the corresponding lumens. Here, we report the function of CESSA in sperm maturation. By local injection of Lentivirus-mediated siRNA in the CESSA.expressing region of the rat epididymis, CesSa-knockdown animal models were created. These animals exhibited an inhibited sperm capacitation and a reduction in male fertility. These results suggest that CESSA plays an important role in sperm maturation and male fertility. 展开更多
关键词 CARBOXYLESTERASE CES5A EPIDIDYMIS male fertility sperm capacitation
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Effects of ubiquitin-protea-some pathway on mouse sperm capacitation, acrosome reaction and in vitro fertilization 被引量:2
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作者 WANG Hongmei SONG Changcheng +4 位作者 DUAN Chongwen SHI Weixian LI Cunxi CHEN Dayuan WANG Yongchao 《Chinese Science Bulletin》 SCIE EI CAS 2002年第2期127-132,共6页
Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody againstubiqui... Chlortetracycline (CTC) fluorescence patterns were used to study changes in the patterns B and AR of mouse sperm after incubation with reagents that would block the UPP. They were the monoclonal antibody againstubiquitinated proteins——UCPi; the polyclonal antibodyagainst ubiquitin-anti-Ub, and a special inhibitor againstproteasome——ALLN. Furthermore, we treated the capaci-tated sperm or the eggs with these reagents separately and tested whether the normal in vitro fertilization was blocked or not. Results illustrate that UCP1, anti-Ub, and ALLN have little effects on sperm capacitation and acrosome reaction, but they do inhibit fusion of mouse sperm with eggs, which suggests that UPP play an important role in mouse in vitro fertilization. 展开更多
关键词 UBIQUITIN-PROTEASOME PATHWAY capacitation ACROSOME reaction in vitro fertilization.
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STUDY ON in vitro SPERM CAPACITATION AND EGG-PENETRATION OF GIANT PANDA 被引量:1
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作者 陈大元 宋祥芬 +5 位作者 赵学坤 段崇文 叶志勇 何光昕 张安居 冯文和 《Science China Chemistry》 SCIE EI CAS 1989年第4期435-441,共7页
<正> A preliminary report on in vitro sperm capacitation and egg-penetration of giant panda is briefly presented. The panda spermatozoon consists of head, neck and tail, just like the spermatozoa of other animal... <正> A preliminary report on in vitro sperm capacitation and egg-penetration of giant panda is briefly presented. The panda spermatozoon consists of head, neck and tail, just like the spermatozoa of other animals. Before capacitation sperm heads clusterd together and dispersed after capacitation. They were then able to swim straight forwared. During the time of in vitro capacitation the plasm membrane of the sperm head was first expanded tov arious degrees, then disintegrated, and finally became detached. The electro-dense material in the acrosome appeared in small clumps with high density. Extensive vesiculation occurred between the bi-layered acrosome membranes and thus led to disintegration. Vesiculation in panda sperm differs from that reported in hamsters. When the capacitated panda spermatozoa came into contact with the hamster eggs, the region between the acrosome collar and postacrosome cap first fused with the egg membrane followed by the penetration of the nucleus into the cortex of the egg. Some o 展开更多
关键词 SPERMATOZOA capacitation penetration in VITRO fertilization.
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Effect of low-dose fenvalerate on semen quality capacitation in adult mice 被引量:1
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作者 SHI Xiao-dan BI Huan-jing FU He-ling LI Liang-yun LIU De-kang LI Jian-min 《Chinese Medical Journal》 SCIE CAS CSCD 2011年第10期1529-1533,共5页
Background Fenvalerate (FEN) has been demonstrated to be a reproductive toxicant in humans and rodents. However,little is known about whether short-term exposure to low-dose FEN produces reproductive toxicity.Method... Background Fenvalerate (FEN) has been demonstrated to be a reproductive toxicant in humans and rodents. However,little is known about whether short-term exposure to low-dose FEN produces reproductive toxicity.Methods We administered FEN (0.009 375, 0.1875, 3.750, or 45.00 mg·kg-1d-1 by gavage for 30 days) to male ICR mice and compared reproductive toxicity parameters between groups receiving different concentrations of FEN.Reproductive toxicity was evaluated by computer-assisted semen quality analysis (CASA), chlortetracycline (CTC) assay,and histopathology.Results The sperm morphology and testis histology of FEN-exposed mice (all doses) were similar to that in controlling mice. Exposure to FEN at a concentration of 0.1875 mg·kg-1d-1 decreased sperm path straightness (STR) and linearity (LIN) (both P〈 0.05), but had no significant impact on average path velocity (VAP), straight line velocity (VSL), curvilinear velocity (VCL), lateral amplitude (ALH), beat cross frequency (BCF), or progressive motility (MOT). FEN reduced the rate of mouse sperm capacitation in a dose-dependent manner.Conclusion The present results demonstrate that exposure to low-dose FEN for 30 days reduces semen quality and sperm capacitation in adult mice. 展开更多
关键词 FENVALERATE capacitation computer-assisted sperm analysis sperm
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Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials
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作者 Xiaona Liu Baohua Zhao +6 位作者 Yanyun Hu Luyue Huang Jingxiang Ma Shuqiao Xu Zhonglin Xia Xiaoying Ma Shuangchen Ma 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第5期23-33,共11页
Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is cruci... Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N. 展开更多
关键词 Anodic oxidation Capacitive deionization Cyclic stability N-DOPING
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Kinetic-Thermodynamic Promotion Engineering toward High-Density Hierarchical and Zn-Doping Activity-Enhancing ZnNiO@CF for High-Capacity Desalination
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作者 Jie Ma Siyang Xing +2 位作者 Yabo Wang Jinhu Yang Fei Yu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期35-50,共16页
Despite the promising potential of transition metal oxides(TMOs)as capacitive deionization(CDI)electrodes,the actual capacity of TMOs electrodes for sodium storage is significantly lower than the theoretical capacity,... Despite the promising potential of transition metal oxides(TMOs)as capacitive deionization(CDI)electrodes,the actual capacity of TMOs electrodes for sodium storage is significantly lower than the theoretical capacity,posing a major obstacle.Herein,we prepared the kinetically favorable Zn_(x)Ni_(1−x)O electrode in situ growth on carbon felt(Zn_(x)Ni_(1−x)O@CF)through constraining the rate of OH^(−)generation in the hydrothermal method.Zn_(x)Ni_(1−x)O@CF exhibited a high-density hierarchical nanosheet structure with three-dimensional open pores,benefitting the ion transport/electron transfer.And tuning the moderate amount of redox-inert Zn-doping can enhance surface electroactive sites,actual activity of redox-active Ni species,and lower adsorption energy,promoting the adsorption kinetic and thermodynamic of the Zn_(0.2)Ni_(0.8)O@CF.Benefitting from the kinetic-thermodynamic facilitation mechanism,Zn_(0.2)Ni_(0.8)O@CF achieved ultrahigh desalination capacity(128.9 mgNaCl g^(-1)),ultra-low energy consumption(0.164 kW h kgNaCl^(-1)),high salt removal rate(1.21 mgNaCl g^(-1) min^(-1)),and good cyclability.The thermodynamic facilitation and Na^(+)intercalation mechanism of Zn_(0.2)Ni_(0.8)O@CF are identified by the density functional theory calculations and electrochemical quartz crystal microbalance with dissipation monitoring,respectively.This research provides new insights into controlling electrochemically favorable morphology and demonstrates that Zn-doping,which is redox-inert,is essential for enhancing the electrochemical performance of CDI electrodes. 展开更多
关键词 Zinc-nickel metal oxide High-density hierarchical Capacitive deionization Zinc-doping
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Customized modulation on plasma uniformity by non-uniform magnetic field in capacitively coupled plasma
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作者 王森 张权治 +2 位作者 马方方 Maksudbek YUSUPOV 王友年 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期79-87,共9页
A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static m... A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static magnetic field, direct current is applied to a circular coil located at the top of the chamber. By adjusting the magnetic field's configuration, which is done by altering the coil current and position, both the plasma uniformity and density can be significantly modulated. In the absence of the magnetic field, the plasma density exhibits an inhomogeneous distribution characterized by higher values at the plasma edge and lower values at the center. The introduction of a magnetic field generated by coils results in a significant increase in electron density near the coils. Furthermore, an increase in the sets of coils improves the uniformity of the plasma. By flexibly adjusting the positions of the coils and the applied current,a substantial enhancement in overall uniformity can be achieved. These findings demonstrate the feasibility of using this method for achieving uniform plasma densities in industrial applications. 展开更多
关键词 COMSOL capacitively coupled plasma plasma uniformity magnetic field
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Flexible capacitive pressure sensor based on interdigital electrodes with porous microneedle arrays for physiological signal monitoring
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作者 Jiahui Xu Minghao Wang +9 位作者 Minyi Jin Siyan Shang Chuner Ni Yili Hu Xun Sun Jun Xu Bowen Ji Le Li Yuhua Cheng Gaofeng Wang 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第1期18-31,共14页
Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stab... Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer. 展开更多
关键词 Capacitive pressure sensor Microneedle array Porous PDMS Interdigital electrode
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Plasma density enhancement in radio-frequency hollow electrode discharge
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作者 贺柳良 何锋 欧阳吉庭 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期44-51,共8页
The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results s... The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results show that plasma exists inside the cavity when the sheath inside the hollow electrode hole is fully collapsed, which is an essential condition for the plasma density enhancement outside hollow electrodes. In addition, the existence of the electron density peak at the orifice is generated via the hollow cathode effect(HCE), which plays an important role in the density enhancement. It is also found that the radial width of bulk plasma at the orifice affects the magnitude of the density enhancement, and narrow radial plasma bulk width at the orifice is not beneficial to obtain high-density plasma outside hollow electrodes.Higher electron density at the orifice, combined with larger radial plasma bulk width at the orifice,causes higher electron density outside hollow electrodes. The results also imply that the HCE strength inside the cavity cannot be determined by the magnitude of the electron density outside hollow electrodes. 展开更多
关键词 RF capacitively coupled plasma sources plasma density enhancement hollow cathodeeffect hollow electrode
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Abnormal transition of the electron energy distribution with excitation of the second harmonic in low-pressure radio-frequency capacitively coupled plasmas
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作者 余乐怡 陆文琪 张丽娜 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第8期58-63,共6页
The self-excited second harmonic in radio-frequency capacitively coupled plasma was significantly enhanced by adjusting the external variable capacitor.At a lower pressure of 3 Pa,the excitation of the second harmonic... The self-excited second harmonic in radio-frequency capacitively coupled plasma was significantly enhanced by adjusting the external variable capacitor.At a lower pressure of 3 Pa,the excitation of the second harmonic caused an abnormal transition of the electron energy probability function,resulting in abrupt changes in the electron density and temperature.Such changes in the electron energy probability function as well as the electron density and temperature were not observed at the higher pressure of 16 Pa under similar harmonic changes.The phenomena are related to the influence of the second harmonic on stochastic heating,which is determined by both amplitude and the relative phase of the harmonics.The results suggest that the self-excited high-order harmonics must be considered in practical applications of lowpressure radio-frequency capacitively coupled plasmas. 展开更多
关键词 RADIO-FREQUENCY capacitively coupled plasma HARMONICS the electron energy probability function
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