水母刺丝囊毒素的提取，溶血活性和毒性的研究

本文研究了水母毒性细胞—刺丝囊的性质、刺丝囊毒素的提取及刺丝囊毒素的溶血活性和毒性等方面的内容。 通过显微镜、扫描电镜及透射电镜分别对霞水母、海蜇、沙蜇触手中所含刺丝囊的形态特点进行了分析，发现三种水母触手中含有不同形状和大小的刺丝囊。应用珠磨式组织研磨器破碎刺丝囊，可有效提取刺丝囊毒素。 霞水母刺丝囊毒素具有明显的溶血活性。4-37°C范围内毒素的溶血活性与温度变化密切相关。毒素溶血活性对pH敏感。胰蛋白酶和鞘磷脂能明显抑制毒素的溶血活性。毒素的溶血活性具有二价金属离子依赖性，Ca2+可能是毒素溶血活性的重要活化剂。EDTA，NaCl及GSH对毒素的溶血活性具有稳定作用。 水母刺丝囊毒素与触手中提取的毒素含有明显不同的蛋白组成，刺丝囊毒素的溶血活性强于触手中提取的毒素。 霞水母刺丝囊毒素表现出明显的神经毒性作用。毒素对草鱼的毒性具有剂量依赖性。霞水母刺丝囊毒素的致死毒性对热的稳定性要比已报道的其它水母毒素强。毒性对pH敏感，胰蛋白酶对毒素的毒性具有明显的抑制作用。毒素的毒性在-80°C稳定。通过DEAE-Sepharose Fast Flow和Sephadex G-100分离霞水母刺丝囊毒素，主要得到两条蛋白谱带，分子量分别为60kDa和47kDa。毒素中的溶血活性成分不具有致死毒性。

互助北山国家森林公园鸟类区系研究初报

互助北山国家森林公园记录到的鸟类有115 种,隶属9 目28 科73 属,其中雀形目鸟类有16科47 属85 种。区系成分以青藏区为主,西南区对其影响最大,华北区与蒙新区影响较小,而华中区没有构成明显影响。虽该森林公园处于祁连山东端,但在动物地理区划上似应划归青藏区青海藏南亚区的青南省。

Formulation of a basal medium for primary cell culture of the marine sponge Hymeniacidon perleve

Marine sponge cell culture is a potential route for the sustainable production of sponge-derived bioproducts. Development of a basal culture medium is a prerequisite for the attachment, spreading, and growth of sponge cells in vitro. With the limited knowledge available on nutrient requirements for sponge cells, a series of statistical experimental designs has been employed to screen and optimize the critical nutrient components including inorganic salts (ferric ion, zinc ion, silicate, and NaCl), amino acids (glycine, glutamine, and aspartic acid), sugars (glucose, sorbitol, and sodium pyruvate), vitamin C, and mammalian cell medium (DMEM and RPMI 1640) using MTT assay in 96-well plates. The marine sponge Hymeniacidon perleve was used as a model system. Plackett-Burman design was used for the initial screening, which identified the significant factors of ferric ion, NaCl, and vitamin C. These three factors were selected for further optimization by Uniform Design and Response Surface Methodology (RSM), respectively. A basal medium was finally established, which supported an over 100% increase in viability of sponge cells.

Improvement of direct methanol fuel cell performance by modifying catalyst coated membrane structure

A five-layer catalyst coated membrane (CCM) based upon Nation 115 membrane for direct methanol fuel cell (DMFC) was designed and fabricated by introducing a modified Nafion layer between the membrane and the catalyst layer. The properties of the CCM were determined by SEM, cyclic voltammetry, impedance spectroscopy, ruinous test and I-V curves. The characterizations show that the modified Nation layers provide increased interface contact area and enhanced interaction between the membrane and the catalyst layer. As a result, higher Pt utilization, lower contact resistance and superior durability of membrane electrode assembly was achieved. A 75% Pt utilization efficiency was obtained by using the novel CCM structure, whereas the conventional structure gave 60% efficiency. All these features greatly contribute to the increase in DMFC performance. The DMFC with new CCM structure presented a maximum power density of 260 MW cm(-2), but the DMFC with conventional structure gave only 200 mW cm(-2) under the same operation condition. (c) 2005 Elsevier B.V. All rights reserved.