AIM： To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-（BSM） encapsulated implanted islets. METHODS： After the ...AIM： To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-（BSM） encapsulated implanted islets. METHODS： After the BSM experiment in vitro, BSM- encapsulated SD rat＇s islet-like cell clusters （ICCs） were xenotransplanted into normal dog＇s brain. Morphological changes were observed under light and transmission electron microscope. The islets and apoptosis of implanted B cells were identified by insulin-TONEL double staining. RESULTS： The BSM used in our study had a favorable permeability, some degree of rigidity, lighter foreign body reaction and toxicity. The grafts consisted of epithelioid cells and loose connective tissue. Severe infiltration of inflammatory cells was not observed. The implanted ICCs were identified 2 mo later and showed typical apoptosis. CONCLUSION： BSM xenotransplantation in combination with the privileged site can inhibit the rejection of implanted heterogeneous ICCs, and death of implanted heterogeneous B cells is associated with apoptosis. 2005 The WJG Press and Elsevier Inc. All rights reserved.展开更多
A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3- methylimidazolium hexafluorophosphate ([C4MIM][PF6...A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3- methylimidazolium hexafluorophosphate ([C4MIM][PF6]) – filled semipermeable membrane. For 24 hrs extraction of naphthalene, 1-methylnaphthalene, 2-chloronaphthalene, phenanthrene, the result showed that the extraction efficiency, correlation coefficient (R2) and RSD (n=5) were in the range of 67-102 %, 0.9870-0.9962, and 2.1-5.3 %, respectively.展开更多
Compacted sand-bentonite mixtures are used as waste containment barriers(e.g.landfill liners and bentonite buffers for nuclear waste)to restrict contaminant transport.The potential for enhanced chemical containment of...Compacted sand-bentonite mixtures are used as waste containment barriers(e.g.landfill liners and bentonite buffers for nuclear waste)to restrict contaminant transport.The potential for enhanced chemical containment of compacted sand-bentonite mixtures due to semipermeable membrane behavior has also been demonstrated.However,the extent to which membrane behavior persists in the presence of highly concentrated chemical solutions,which have been shown to degrade membrane behavior in bentonite-based barriers,remains largely unknown.Moreover,the limiting(threshold)salt concentrations at which membrane behavior of compacted sand-bentonite mixtures is effectively destroyed have not been evaluated.Accordingly,this study quantified the limiting membrane behavior of two duplicated specimens of compacted sand-bentonite mixture comprising 15%sodium bentonite(by dry mass)by determining the limiting salt concentrations at which measurable membrane behavior was eliminated.The specimens were exposed to increasingly higher source concentrations,Cot,of boundary monovalent salt solutions(KCl and NaCl)until measured values of the membrane efficiency coefficient,ω,were effectively zero.Overall,ωdecreased from an average of 0.032 to zero as Cot increased from 160 mmol/L KCl to 3.27 mol/L NaCl,resulting in limiting threshold salt concentrations for the two tests between 1.63 mol/L and 3.27 mol/L NaCl,which are significantly higher than those at which measurable membrane behavior has previously been demonstrated.展开更多
In this paper, we consider elliptic hemivariational inequalities arising in applications in semipermeable media. In its general form, the model includes both interior and boundary semipermeability terms. Detailed stud...In this paper, we consider elliptic hemivariational inequalities arising in applications in semipermeable media. In its general form, the model includes both interior and boundary semipermeability terms. Detailed study is given on the hemivariational inequality in the case of isotropic and homogeneous semipermeable media. Solution existence and uniqueness of the problem are explored. Convergence of the Galerkin method is shown under the basic solution regularity available from the existence result. An optimal order error estimate is derived for the linear finite element solution under suitable solution regularity assumptions. The results can be readily extended to the study of more general hemivariational inequalities for non-isotropic and heterogeneous semipermeable media with interior semipermeability and/or boundary semiperrneability. Numerical examples are presented to show the performance of the finite element approximations;in particular, the theoretically predicted optimal first order convergence in H' norm of the linear element solutions is clearly observed.展开更多
The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） pas...The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.展开更多
The evaluation of estrogenic activities and aryl hydrocarbon receptor (AhR) agonists in water from Three Gorges Reservoir (TGR) China was conducted by in vitro bioassays combined with SPMD-based virtual organisms (VO)...The evaluation of estrogenic activities and aryl hydrocarbon receptor (AhR) agonists in water from Three Gorges Reservoir (TGR) China was conducted by in vitro bioassays combined with SPMD-based virtual organisms (VO). VOs were deployed at seven sites in the Three Gorges Reservoir (TGR), China for two periods in 2009. The estrogenic activity was assessed using a rapid yeast estrogen bioassay, based on the expression of a green fluorescent reporter protein (yEGFP). The AhR activity was detected employing rat hepatoma cell line (H4IIE). The results indicate that AhR agonists distributed widely in water of TGR and almost homogenously distributed in most area of TGR. Weak antiestrogenic activities were also found homogenously distributed in water of TGR. Further studies are needed to determine the identities of these estrogenic compounds and AhR agonists and their potential adverse effects on wild biota in TGR.展开更多
基金Supported by the Natural Science Foundation of Shaanxi Province, No. 98SZ-064
文摘AIM： To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-（BSM） encapsulated implanted islets. METHODS： After the BSM experiment in vitro, BSM- encapsulated SD rat＇s islet-like cell clusters （ICCs） were xenotransplanted into normal dog＇s brain. Morphological changes were observed under light and transmission electron microscope. The islets and apoptosis of implanted B cells were identified by insulin-TONEL double staining. RESULTS： The BSM used in our study had a favorable permeability, some degree of rigidity, lighter foreign body reaction and toxicity. The grafts consisted of epithelioid cells and loose connective tissue. Severe infiltration of inflammatory cells was not observed. The implanted ICCs were identified 2 mo later and showed typical apoptosis. CONCLUSION： BSM xenotransplantation in combination with the privileged site can inhibit the rejection of implanted heterogeneous ICCs, and death of implanted heterogeneous B cells is associated with apoptosis. 2005 The WJG Press and Elsevier Inc. All rights reserved.
基金the National Natural Science Foundation of China(No.20377025)
文摘A novel and facile sample preparation method was developed for the extraction of polycyclic aromatic hydrocarbons (PAHs) in aqueous sample solution using 1-butyl-3- methylimidazolium hexafluorophosphate ([C4MIM][PF6]) – filled semipermeable membrane. For 24 hrs extraction of naphthalene, 1-methylnaphthalene, 2-chloronaphthalene, phenanthrene, the result showed that the extraction efficiency, correlation coefficient (R2) and RSD (n=5) were in the range of 67-102 %, 0.9870-0.9962, and 2.1-5.3 %, respectively.
文摘Compacted sand-bentonite mixtures are used as waste containment barriers(e.g.landfill liners and bentonite buffers for nuclear waste)to restrict contaminant transport.The potential for enhanced chemical containment of compacted sand-bentonite mixtures due to semipermeable membrane behavior has also been demonstrated.However,the extent to which membrane behavior persists in the presence of highly concentrated chemical solutions,which have been shown to degrade membrane behavior in bentonite-based barriers,remains largely unknown.Moreover,the limiting(threshold)salt concentrations at which membrane behavior of compacted sand-bentonite mixtures is effectively destroyed have not been evaluated.Accordingly,this study quantified the limiting membrane behavior of two duplicated specimens of compacted sand-bentonite mixture comprising 15%sodium bentonite(by dry mass)by determining the limiting salt concentrations at which measurable membrane behavior was eliminated.The specimens were exposed to increasingly higher source concentrations,Cot,of boundary monovalent salt solutions(KCl and NaCl)until measured values of the membrane efficiency coefficient,ω,were effectively zero.Overall,ωdecreased from an average of 0.032 to zero as Cot increased from 160 mmol/L KCl to 3.27 mol/L NaCl,resulting in limiting threshold salt concentrations for the two tests between 1.63 mol/L and 3.27 mol/L NaCl,which are significantly higher than those at which measurable membrane behavior has previously been demonstrated.
文摘In this paper, we consider elliptic hemivariational inequalities arising in applications in semipermeable media. In its general form, the model includes both interior and boundary semipermeability terms. Detailed study is given on the hemivariational inequality in the case of isotropic and homogeneous semipermeable media. Solution existence and uniqueness of the problem are explored. Convergence of the Galerkin method is shown under the basic solution regularity available from the existence result. An optimal order error estimate is derived for the linear finite element solution under suitable solution regularity assumptions. The results can be readily extended to the study of more general hemivariational inequalities for non-isotropic and heterogeneous semipermeable media with interior semipermeability and/or boundary semiperrneability. Numerical examples are presented to show the performance of the finite element approximations;in particular, the theoretically predicted optimal first order convergence in H' norm of the linear element solutions is clearly observed.
基金supported by the National Natural Science Foundation of China (No.20877011)the DAAD (German Academic Exchange Service) Scientific Research Visiting Scholarship+3 种基金the Chinese National Programs for High Technology Research and Development (No.2011AA060604)the State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (No.KF2009-17)the Key Laboratory of Industrial Ecology and Environmental Engineering,Ministry of Education of China (No.0802)the Scientific Research Foundation for Returned Overseas Chinese Scholars,Ministry of Education of China
文摘The concentration of polychlorinated biphenyls （PCBs） in the urban air of Dalian, China was monitored from November 2009 to October 2010 with active high-volume sampler and semipermeable membrane device （SPMD） passive sampler. The concentration of PCBs （particle ＋ gas） （∑PCBs） ranged from 18.6 to 91.0 pg/m3, with an average of 50.9 pg/m3, and the most abundant dioxin-like PCB （DL-PCBs） was PCB118. The WHO-TEQ values of DL-PCBs were 3.6--22.1 fg/m3, with an average of 8.5 fg/m3, and PCB126 was the maximum contributor to ZTEQ. There was a much larger amount of PCBs in the gas phase than in the particulate phase. The dominant PCB components were lower and middle molecular weight PCBs. With increasing chlorination level, the concentration of the PCB congeners in the air decreased. The gas-particulate partitioning of PCBs was different for the four seasons. The gas- particulate partitioning coefficients （logKp） vs. subcooled liquid vapor pressures （logPL~） of PCBs had reasonable correlations for different sampling sites and seasons. The absorption mechanism contributed more to the gas-particulate partitioning process than adsorption. Correlation analysis of meteorological parameters with the concentration of PCBs was conducted using SPSS packages. The ambient temperature and atmospheric pressure were important factors influencing the concentration of PCBs in the air. The distribution pattern of the congeners of PCBs and the dominant contributors to DL-PCBs and TEQ in active samples and SPMDs passive samples were similar. SPMD mainly sequestrated gas phase PCBs.
文摘The evaluation of estrogenic activities and aryl hydrocarbon receptor (AhR) agonists in water from Three Gorges Reservoir (TGR) China was conducted by in vitro bioassays combined with SPMD-based virtual organisms (VO). VOs were deployed at seven sites in the Three Gorges Reservoir (TGR), China for two periods in 2009. The estrogenic activity was assessed using a rapid yeast estrogen bioassay, based on the expression of a green fluorescent reporter protein (yEGFP). The AhR activity was detected employing rat hepatoma cell line (H4IIE). The results indicate that AhR agonists distributed widely in water of TGR and almost homogenously distributed in most area of TGR. Weak antiestrogenic activities were also found homogenously distributed in water of TGR. Further studies are needed to determine the identities of these estrogenic compounds and AhR agonists and their potential adverse effects on wild biota in TGR.
