抗菌肽与细胞膜相互作用机制的分子动力学模拟研究

抗菌肽由于其具有天然抗菌特性,且对生物体毒副作用小,有望作为新一代抗菌药物而得到了广泛的关注.作为研究生物大分子的有效工具,分子动力学模拟技术被用来研究抗菌肽的抗菌机制及与细菌膜的相互作用.回顾近年来抗菌肽与膜相互作用分子动力学模拟研究,理清利用全原子模型和粗粒化模型模拟抗菌肽与细菌膜作用情况,包括模拟力场的选择、细菌膜模型的建立,以及利用模拟得到肽/膜作用信息等,对了解抗菌肽的抗菌活性及新药设计提供帮助.     

生物工程膜分离技术

生物工程是当今世界高技术发展的重要领域。下游技术是生物高技术实现产业化的关键。膜分离技术是下游技术中一项新近发展的、具有广泛应用前景的单元操作．本文介绍了膜分离技术的优点、几种主要膜分离过程及其操作中存在的问题。     

Light-driven directional ion transport for enhanced osmotic energy harvesting

Light-driven ion (proton) transport is a crucial process both for photosynthesis of green plants and solar energy harvesting of some archaea. Here, we describe use of a TiO₂/C₃N₄ semiconductor heterojunction nanotube membrane to realize similar light-driven directional ion transport performance to that of biological systems. This heterojunction system can be fabricated by two simple deposition steps. Under unilateral illumination, the TiO₂/C₃N₄ heterojunction nanotube membrane can generate a photocurrent of about 9 μA/cm², corresponding to a pumping stream of ∼5500 ions per second per nanotube. By changing the position of TiO₂ and C₃N₄, a reverse equivalent ionic current can also be realized. Directional transport of photogenerated electrons and holes results in a transmembrane potential, which is the basis of the light-driven ion transport phenomenon. As a proof of concept, we also show that this system can be used for enhanced osmotic energy generation. The artificial light-driven ion transport system proposed here offers a further step forward on the roadmap for development of ionic photoelectric conversion and integration into other applications, for example water desalination.     

生物慢滤柱处理水窖水的运行试验研究

为保障西北村镇饮用水安全,选用生物慢滤对窖水进行处理。通过自然挂膜的方式研究了填充铁改性沸石的慢滤柱对浊度、氨氮和CODMn的去除效果,改变滤速和断流天数考察装置的运行能力。研究表明:慢滤柱30天形成生物膜,稳定后能有效去除水中的各项污染物,对浊度、氨氮和CODMn的平均去除率分别为96.67%、87.13%和42.86%;滤速增加各去除率降低;断流后滤柱恢复时间很短;慢滤柱对实际雨水也有很好的去除效果,适用于西北村镇分散式供水。     

中国有机分离膜的专利现状与产业对策

采用计算机检索和人工标引等方法,对近三十年来中国有机分离膜专利数据进行提取和加工。从宏观、中观和微观三个层面入手,分析了时间分布、地域分布、类别分布和创新主体情况,并通过中外对比,揭示了当前中国有机分离膜产业发展的五个趋势特征,提出了布局上游专利、降低风险水平、促进技术转移、加强协同创新等对策建议。     

Berbamine induces apoptosis in human hepatoma cell line SMMC7721 by loss in mitochondrial transmembrane potential and caspase activation

Objective： To investigate the effect ofberbamine on human hepatoma cell line SMMC7721. Methods： The effects of 24 h and 48 h incubation with different concentrations （0-64 μg/ml） of the berbamine on SMMC7721 cells were evaluated using 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide （MTT） assay. Hoechst 33258 staining was conducted to distinguish the apoptotic cell, and the appearance of sub-G1 stage was determined by PI （propidium iodide） staining, the percentage of apoptotic cell was determined by flow cytometry following annexin V/PI staining. Flow cytometry was performed to analyze the cell cycle distribution and the mitochondrial membrane potential （△ψm）, the expression of activated caspase3 and caspase9 was analyzed by Western-blot. Results： The proliferation of SMMC7721 was decreased after treatment with berbamine in a dose- and time-dependent manner. Berbamine could induce apoptosis in SMMC7721 cells and could cause cell cycle arrest in G0/G1 phase, to induce loss of mitochondrial membrane potential （AVm） and activate caspase3 and caspase9. Berbamine-induced apoptosis could be blocked by the broad caspase inhibitor z-VAD-fmk. Conclusion： Berbamine exerts antiproliferative effects on human hepatocellular carcinoma SMMC7721 cells. The anticancer activity of berbamine could be attributed partly to its inhibition of cell proliferation and induction of apoptosis in cancer cells through loss in mitochondrial transmembrane potential and caspase activation.     

膜蒸馏技术进展

对膜蒸馏的过程机理，影响因素，用膜材料等进行了讨论，同时介绍了膜蒸馏的海水淡化，水溶液的分离与浓缩，工业废水的治理等中的应用，并在上基础上提出了膜蒸馏的发展方向。     

Energy storage system with ultracapacitors for thermal underwater glider

A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS.     

蓝绿温和胶电泳及其在植物类囊体膜蛋白组研究中的应用

蓝绿温和胶电泳（BN-PAGE）以其温和、高效的优势,越来越多的被应用于植物研究领域。而类囊体作为植物光合作用的重要场所,在植物蛋白质组学研究中倍受关注。着重介绍了BN-PAGE在植物类囊体蛋白组学研究方面的应用,同时对BN-PAGE在此领域的应用趋势进行了探讨。     

Administering the Optimum Dose of l-Arginine in Regional Tumor Therapy

The purpose of this study is optimizing the l-arginine (l-Arg) doses on the basis of chemical structure in regional accessible tumor therapy to settle down a new protocol for the treatment of cancer. ³H-thymidine-based cell proliferation assay was performed in vitro on tumor cell lines of fibrosarcoma (FS), lymphosarcoma-ascitic and on normal cell line of NIH 3T3 after treatment with different concentrations of l-Arg in phosphate buffered saline (PBS). The cultures were harvested after 22 h and the incorporated radioactivity was counted to identify their histologic grades as described in earlier studies. In vivo therapy of murine tumors was conducted where FS cells injected subcutaneously at ventro-lateral position of mice. Various drug delivery schedules were injected into the centre of tumor base, once a day for 4 days. Tumor diameter and survivals were monitored where the day of sacrifice was considered for monitoring the survival period. By identifying the histologic grades of the treated cultures in vitro and in vivo by different concentrations of l-Arg, the corresponding energy of such concentrations were determined. An efficient model with a good fit (R² = 0.98) was established to describe the energy yield by l-Arg dose. The equivalence between the tumor histologic grade and energy of the l-Arg dose delivered in saline (PBS) environment is the optimum condition for regional tumor therapy achieves higher survival rate. The selective cytotoxicity to tumor cells with minimal damage to normal cells by l-Arg due to its chemical structure suggests to be considered the most promising drug for regional therapy of the accessible tumors like breast cancers of early stage with no distant metastasis.