薄层电解池分析技术研究——串联式电池分析法的应用

本文介绍用双工作电极串联式的薄层电池,结合阳极溶出伏安法,用上游工作电极作富集-溶出电极;下游工作电极作收集电极,记录下游工作电极的收集电流。本法具有溶出法和薄层伏安法的优点,可消除电位扫描引入的电容电流,以及吸附电流、杂质电流的干扰,有效地提高了信噪比,提高了测定的灵敏度和分辨率。     

细胞表面壳化的研究进展

细胞表面壳化主要是通过物理、化学等技术方法对细胞表面进行修饰,形成完整均匀的有机、无机、金属纳米粒子或者复合壳层结构,从而使不能自身壳化的生物细胞表面形成保护壳甚至赋予细胞新的功能,使细胞具备多功能性。近年来,此技术在细胞存储、细胞运输、细胞传感器、细胞芯片以及细胞治疗等方面应用广泛,发展迅速。本文综合目前的研究现状,详细介绍了可进行细胞表面壳化的细胞类型、生物表面壳化的方法以及人造细胞外壳的工程技术在生物医学以及能源环境中的应用等。     

燃料电池技术的发展与我国应有的对策

本文介绍了几种主要类型燃料电池的最新进展，基于世界发展趋势和我国具体情况，作者在碱性燃料电池，磷酸型燃料电池，溶融碳酸盐电池和聚合物电解质燃料电池方面提出了相应对策。以促进我国燃料电池的研究与开发。     

新型透射式红外光谱电化学池

本文报道一种新型透射式红外光谱电化学池的设计制作。应用盐片加工技术,采用内参比点设置等方法。使该池达到30μm的厚度,且具有十分良好的电化学性能。     

Recent Advances in DNA-Based Cell Surface Engineering for Biological Applications

Due to its excellent programmability and biocompatibility, DNA molecule has unique advantages in cell surface engineering. Recent progresses provide a reliable and feasible way to engineer cell surfaces with diverse DNA molecules and DNA nanostructures. The abundant form of DNA nanostructures has greatly expanded the toolbox of DNA-based cell surface engineering and gave rise to a variety of novel and fascinating applications. In this review, we summarize recent advances in DNA-based cell surface engineering and its biological applications. We first introduce some widely used methods of immobilizing DNA molecules on cell surfaces and their application features. Then we discuss the approaches of employing DNA nanostructures and dynamic DNA nanotechnology as elements for creating functional cell surfaces. Finally, we review the extensive biological applications of DNA-based cell surface engineering and discuss the challenges and prospects of DNA-based cell surface engineering.     

一种新的双光系统透明电极电池

植物光合作用在其叶绿体的光合作用膜上进行。它有两个串联着的光系统(PSII和PSI)。PSII在膜的一侧,吸收波长相当于680nm的光子激发电子并产生空穴,空穴将水氧化得氧。电子经过一系列的下坡传送,暗反应合成ATP,到处于膜另一侧的PSI。PSI吸收波长相当于700nm的光子,再次将电子激发,经过第二个系列的下坡传送,暗反应将NADP还原为NADHP。NADHP和ATP最终将CO₂还原为碳水化合物。     

Control of endothelial cell adhesion to polymer surface by ion implantation

The bio‐compatibility of ion implanted polymers has been studied by means of in vitro attachment measurements of bovine aorta endothelial cells. The specimens used were polystyrene (PS), polyethylene (PE), polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). He⁺ and Ne⁺ ion implantation were performed at an energy of 150 keV with fluences between 1 × 10 ¹³ to 1 × 10 ¹⁷ ions/cm ² at room temperature. Wettability was estimated by means of a sessile drop method. The chemical and physical structures of ion implanted polymers were investigated by contact angle measurements, atomic force microscopy and X‐ray photoelectron spectroscopic analysis in relation to cell attachment behavior. The strength of cell attachment on ion implanted specimens at static and under flow conditions was also measured. Ion implanted PP and ePTFE were found to exhibit remarkably higher adhesion and spreading of endothelial cells than non‐implanted specimens. In contrast to these findings, ion implanted PS and PE only demonstrated a little improvement of cell adhesion in this assay. Copyright © 2001 John Wiley & Sons, Ltd.     

燃料电池汽车氢源选择的研究进展和预测

燃料电池汽车被认为是能源和交通领域的新方向之一,而目前氢源问题已成为其商业化的技术瓶颈。本文从国内外燃料电池汽车的发展现状出发,结合国外对燃料电池汽车氢源选择的评估和预测,及国内863计划“燃料电池汽车氢源基础设施工程前期研究”项目的研究结论,对我国燃料电池汽车的技术发展和商业化进程进行了预测。     

光子晶体太阳能电池研究进展

光子晶体具有光子禁带、“慢光子”效应等独特的光学性能,近年来被广泛用于太阳能电池中.光子晶体的引入,可调节光子在太阳能电池中的传播和分布.在电池中不同的位置引入光子晶体,能够提高或抑制太阳能电池的光电转化效率.因此充分了解光子晶体的光学特性,正确使用光子晶体是提高光电转化效率的关键.本文总结归纳不同类型光子晶体在硅太阳能电池及敏化型太阳能电池中的应用,并对其可能存在的问题进行了分析和评述.     

A low-cost and high-throughput benchtop cell sorter for isolating white blood cells from whole blood

The ability to isolate and purify white blood cells (WBCs) from mixed ensembles such as blood would benefit autologous cell-based therapeutics as well as diagnosis of WBC disorders. Current WBCs isolation methods have the limitations of low purity or requiring complex and expensive equipment. In addition, due to the overlap in size distribution between lymphocytes (i.e., a sub-population of WBCs) and red blood cells (RBCs), it is challenging to achieve isolation of entire WBCs populations. In this work, we developed an inertial microfluidics-based cell sorter, which enables size-based, high-throughput isolation, and enrichment of WBCs from RBC-lysed whole blood. Using the developed inertial microfluidic chip, the sorting resolution is sharpened within 2 μm, which achieved separation between 3 and 5 μm diameter particles. Thus, with the present cell sorter, a full population of WBCs can be isolated from RBC-lysed blood samples with recovery ratio of 92%, and merely 5% difference in the composition percentage of the three subpopulations of granulocytes, monocytes, and lymphocytes compared to the original sample. Furthermore, our cell sorter is designed to enable broad application of size-based inertial cell sorting by supplying a series of microchips with different sorting cutoff size. This strategy allows us to further enrich the lymphocytes population by twofold using another microchip with a cutoff size between 10 and 15 μm. With simplicity and efficiency, our cell sorter provides a powerful platform for isolating and sorting of WBCs and also envisions broad potential sorting applications for other cell types.     

硒化壳聚糖诱导NB4细胞凋亡及周期阻断作用

为研究硒化壳聚糖对NB4细胞的凋亡及周期阻断作用,用流式细胞法观察了药物对细胞的诱导凋亡及周期阻断作用。结果表明,硒化壳聚糖作用NB4细胞24 h,可剂量依赖性地诱导细胞凋亡并使G0—G1期细胞增多。提示硒化壳聚糖可诱导细胞凋亡,并对NB4细胞周期有特异性阻断作用。     

Lactase in Immobilized Cells of Watermelon

A cell suspension culture of Citrullus vulgaris Schrad cv. Samara was permeabilized by Tween 80 and immobilized by glutaraldehyde. The highest lactase activity was achieved at pH 4.3, the temperature optimum for cell suspension was at 50°C, while for the immobilized cells the optimum was at 58°C. The hydrolysis of substrate was linear for 3 h, reaching 60-67% conversion rate. The cells were characterized by high enzyme activity. The stability of the enzyme showed convenient physico-mechanical properties (physical protection from shear forces and easy separation of product from biocatalysts) in long-term storage.     

电极表面状态对原电池影响的热力学分析

１前言我们知道，超细微粒及其材料具有许多优异的物理化学性质［１～６］；这是因为随着物质分散度的增加，比表面积和表面能也相应增加，从而产生了强烈的表面效应，导致体系在分散状态时的物理化学性质与块状时相比发生了显著变化。我们知道，表面粗糙的金属容易发生电...     

Analysis of phosphorus herbicides by ion-pairing reversed-phase liquid chromatography coupled to inductively coupled plasma mass spectrometry with octapole reaction cell

A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate. Tetrabutylammonium hydroxide is used as the ion-pairing reagent in conjunction with an ammonium acetate/acetic acid buffering system at pH 4.7. An inductively coupled plasma mass spectrometer (ICP-MS) is coupled to the chromatographic system to detect the herbicides at m/z = 31P. Historically, phosphorus has been recognized as one of the elements difficult to analyze in argon plasma. This is due to its relatively high ionization potential (10.5 eV) as well as the inherent presence of the polyatomic interferences 14N16O1H+ and 15N16O+ overlapping its only isotope at m/z = 31. An octapole reaction cell is utilized to minimize the isobaric polyatomic interferences and to obtain the highest signal-to-background ratio. Detection limits were found to be in the low ppt range (25-32 ng/l). The developed method is successfully applied to the analysis of water samples collected from the Ohio River and spiked with a standard compounds at a level of 20 microg/l.     

AFM研究蝙蝠葛碱对daudi细胞毒性的影响

利用原子力显微镜、CCK-8实验和流式细胞术研究了蝙蝠葛碱(dauricine)对B细胞淋巴瘤daudi细胞的细胞毒性。蝙蝠葛碱能显著抑制daudi细胞的增殖。CCK-8实验表明,细胞存活率与蝙蝠葛碱浓度存在时间依赖和剂量依赖关系。经10～50μmol/L的蝙蝠葛碱作用24 h后,daudi细胞存活率从(89.8±4.3)%降至(11.2±3.2)%;48 h后,存活率从(68.9±2.6)%降至(2.5±0.5)%。流式细胞术表明蝙蝠葛碱处理dau-di细胞24 h后,凋亡率从5.2%增至28.2%(60μmol/L)。AFM数据显示对照组细胞呈圆形,表面较光滑。经蝙蝠葛碱处理后,daudi细胞坍塌,超微结构显示细胞表面粗糙、凹凸不平。此外,经不同浓度蝙蝠葛碱作用的daudi细胞,其线粒体膜电位随着药物浓度的加大而降低。蝙蝠葛碱能显著抑制daudi细胞生长增殖。     

Studies of a photosynthetic photoelectrochemical cell using various electrodes

We have developed a photochemical cell using a combination of photosynthetic electron transport (photosystem I particles) and the photoreduction of a dye such as flavin mononucleotide (FMN) (6). The overall power conversion efficiency depends on the rate of charge transfer across the electrode surfaces in addition to the efficiency of the photosynthetic and photochemical reactions. For this reason, we studied the effect of varying the nature of the electrodes on the power developed. We found that reticulated vitreous carbon electrodes showed higher power conversion efficiencies than did nickel mesh, platinum, or SnO₂ glass. There are two reasons for this. First, the ratio of actual to apparent surface area is greater for RVC electrodes than for the others. Second, FMN and its photoproducts react better with carbon than platinum electrodes. Substituting RVC electrodes for platinum increased the power conversion efficiency from 1.0 to 3.9%. Platinizing platinum, nickel mesh, or brass electrodes also increased the power developed. However, the photopotential remained stable for several hours only for the platinized platinum electrodes.     

Cross-talk between BubR1 expression and the commitment to differentiate in adipose-derived mesenchymal stem cells

BubR1 mitotic checkpoint kinase monitors attachment of microtubules to kinetochores and links regulation of the chromosome-spindle attachment to mitotic checkpoint signaling. Defects in BubR1-mediated signaling severely perturb checkpoint control and are linked to diseases such as cancer. Studies using BubR1 mouse models suggest that BubR1 activities prevent premature aging and infertility. In this study, we show that BubR1 depletion in human adipose-derived mesenchymal stem cells (ASCs) precedes loss of the differentiation potential and induction of replicative senescence. These effects occur independently of p16^INK4A expression and may involve DNA methylation. Our results reveal a new and unsuspected feature of BubR1 expression in regulation of adult stem cell differentiation.