Intracerebral xenotransplantation of semipermeable membrane- encapsuled pancreatic islets

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.

Use of Ionic Liquid-filled Semipermeable Membrane for Extraction of Polycyclic Aromatic Hydrocarbons in Water

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.

Evaluation of Estrogenic Receptor (ER) and Aryl Hydrocarbon Receptor (AhR) Agonists in Three Gorges Reservoir, China Using SPMD-Based Virtual Organisms

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.

NUMERICAL ANALYSIS OF ELLIPTIC HEMIVARIATIONAL INEQUALITIES FOR SEMIPERMEABLE MEDIA

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.

Simultaneous monitoring of PCB profiles in the urban air of Dalian,China with active and passive samplings

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.

Structure of Solution of Colloid and Hydrogen Bonding Fluid Near a Semipermeable Membrane

The local fluid structure of a solution consisting of colloid particles and hydrogen bonding（HB） fluid se-parated from pure solvent by a semipermeable membrane was investigated, where the colloid particles and HB fluidserve as solute and solvent, respectively. In this paper, the semipermeable membrane allows the passage of solventmolecules but not solute particles, and therefore, it provides a nano-confinement for colloid particles. The densityprofiles of the two species near the semipermeable membrane were determined via density functional theory（DFT）for classical fluids. Based on the predicted density profiles under various conditions, the effects of HB strength, func-tionality, total bulk density, density fraction and the size ratio of two species on the fluid structure were discussed. Asan application, the osmotic pressures of the system were also presented. It is shown that the local structure andosmotic pressure can be efficiently regulated by these factors due to the competition between the excluded volumeinteractions and the FIB interaction. The present results are expected to be helpful to study the osmotic phenomenaand relevant problems on the nanoscale.