抗坏血酸和亚硒酸钠对肝癌细胞逆转的研究

采用细胞倍增时间、分裂指数、生化变化和软琼脂克隆形成率等指标测定分化,研究了抗坏血酸和亚硒酸钠对人肝癌细胞逆转的作用.结果表明用抗坏血酸4mmol*L-1联合亚硒酸钠2μmol*L-1处理细胞后,细胞的生长率和有丝分裂指数都显著下降.一些与细胞恶性表型有关的指标,如细胞表面电荷明显下降,电泳率从1.74μm*s-1*V-1*cm-1下降到0.91μm*s-1*V-1*un－1,甲胎蛋白含量从331μg*g-1(蛋白)下降到90μg*g-1,γ-谷氨酰转肽酶活性从0.74U*g-1(蛋白)下降到0.19U*g-1.与细胞分化有关的指标,如酪氨酸-α-酮戊二酸转氨酶（TAT）的活性从14.7μmol*g-1(蛋白)升高至42.6μmol*g-1,软琼脂克隆形成能力下降94.7%.由此可见,抗坏血酸和亚硒酸钠联合能诱导肝癌细胞在分化,逆转肿瘤细胞的恶性表型.     

Gene transfer into primary cultures of fetal neural stem cells by a recombinant adenovirus carrying the gene for green fluorescent protein

Objective： To evaluate the transduction efficiency of a recombinant adenovirus carrying the gene for green fluorescent protein （Ad-GFP） into the primary cultures of fetal neural stem cells （NSCs） by the expression of GFP. Methods： The Ad-GFP was constructed by homologous recombination in bacteria with the AdEasy system; NSCs were isolated from rat fetal hippocampus and cultured as neurosphere suspensions. After infection with the recombinant Ad-GFP, NSCs were examined with a fluorescent microscopy and a flow cytometry for their expression of GFP. Results： After the viral infection, flow cytometry analysis revealed that the percentage of GFP-positive cells was as high as 97.05%. The infected NSCs sustained the GFP expression for above 4 weeks. After differentiated into astrocytes or neurons, they continued to express GFP efficiently. Conclusion： We have success- fully constructed a viral vector Ad-GFP that can efficiently infect the primary NSCs. The reporter gene was showed fully and sustained expression in the infected cells as well as their differentiated progenies.     

Some latest achievements in immunology research

Immunology has become as an attractive discipline of biomedical science in the 21st century,integrated with the rapid development of molecular biology,cell biology,structural biology,genetics and other branches in life sciences.A special issue of Sci China Life Sci was published in February 2010 to highlight recent progresses in immunology.Six review articles focusing on various specific topics were contributed by leading scientists who work in respective fields of immunology.Some progresses of immunology research in China are also described.     

In vitro screening of immunomodulatory activity of polysaccharides of nine species of plants in Guizhou province

目的：评价9种黔产植物多糖的免疫调节作用。方法制备脾淋巴细胞悬液,分别将样品与LPS或ConA共同作用于脾淋巴细胞,用MTT法测定淋巴细胞的增殖情况。将多糖作用于RAW264.7细胞,用ELISA测定细胞上清中TNF-α含量,判断样品对RAW264.7细胞的活化情况。结果：土党参多糖、薯蓣多糖、竹根假万寿竹多糖对LPS刺激B淋巴细胞增殖有促进作用。楮实多糖对ConA刺激T淋巴细胞的增殖有促进作用。轮叶沙参多糖、绞股蓝多糖、党参多糖、金樱子多糖对T、B淋巴细胞增殖均有促进作用。而绞股蓝多糖、薯蓣多糖、金樱子多糖、楮实多糖、竹根假万寿竹多糖能诱导RAW264.7细胞TNF-α表达上调。结论：九种黔产植物多糖在促淋巴细胞增殖和巨噬细胞活化中表现出明显差异,其中绞股蓝多糖有较好的免疫增强活性。     

Pyrolysis of Iron(III) porphyrin coated Pt/C toward oxygen reduction reaction in acidic medium

Design and synthesis of highly active and durable electrocatalysts toward oxygen reduction reaction (ORR) is of particular importance for proton exchange membrane fuel cells (PEMFCs), yet remains a grand challenge. Herein, we report the deposition of iron (III) porphyrin (FeP) on house-made Pt/C by rotary evaporation of the mixture of FeP and house-made Pt/C dispersed in chloroform, followed by pyrolysis at 650 °C in argon atmosphere. This approach led to the synthesis of new non-precious metal electrocatalyst (NPME)-Pt/C composites (Pt/C–FeP) with an average nanoparticle diameter of 3.1 ± 1.5 nm without aggregation. According to X-ray photoelectron spectroscopy (XPS), the binding energy of Pt 4f_7/2 became larger due to the presence of pyrolyzed FeP. In addition, the electrochemically active surface area (ECSA) of Pt/C–FeP-650 is 65 m²/g less than that of house-made Pt/C (80.2 m²/g). This implies that the pyrolyzed FeP may have partially covered the surface of Pt nanoparticles and thus lowering the ECSA. Interestingly, the mass activity (MA) of Pt/C–FeP turns out to be 349.0 mA/mg_Pt @0.9 V vs. RHE, which is 2.6 times and 1.5 times of house-made Pt/C and commercial Pt/C, respectively. It is speculated that the electronic interaction and possible synergy between Pt and pyrolyzed FeP as NPME might have contributed to the ORR activity improvement despite of partial loss of ECSA. During accelerated durability tests (ADTs), the MA of Pt/C–FeP-650 degrades 64.3% inferior to commercial Pt/C (52.2%). The main reason likely arises from the degradation of pyrolyzed FeP, which is a bottleneck problem confronting NPMEs.     

低成本选择性发射区太阳电池的制备和特性

运用Matlab软件，在电池能量损耗最小前提下，对选择性发射极（Slective Emitter，SE）电池的栅线间距和宽度进行了模拟计算.在理论计算指导下，在国产化设备的太阳电池生产线上，采用印刷技术实现选择性磷源涂覆和扩散，并制成电池，通过电化学测试、伏安曲线、量子效率（Quantum Efficiency，QE）等检测分析，初步发现，印刷涂覆的SE太阳电池输出特性优于常规工艺制备的电池，转化效率提高约1%.     

溶剂退火处理空穴传输层对改善钙钛矿电池性能的研究

近年来,基于CH_3NH_3PbX_3(X=Cl,Br,I)材料的钙钛矿太阳能电池发展迅速。控制钙钛矿电池中每一层的形貌对于提高电池性能的影响至关重要。使用溶剂退火的方法处理空穴传输层(spiro-OMeTAD),使其表面形貌更加平整均匀,从而改善了空穴传输层与金属电极的接触,减小了电阻,更加有利于电子的传输和收集。使用氯仿进行溶剂退火以后,钙钛矿电池光电转化效率从原来的11.3%提高到了13.1%。其中开路电压、短路电流密度、和填充因子均有大幅提高。电池的迟滞现象从原来的8.8%减小到1.5%。经过长时间测试,使用溶剂退火以后的电池稳定性也有明显改善。研究论证了溶剂退火处理空穴传输层对于制备高性能、低迟滞、更稳定的钙钛矿太阳能电池具有至关重要的作用。     

小鼠NPC细胞RFX1ChIP-Seq数据分析

利用NCBI数据库中小鼠Embryonic Stem Cells(ESC)与Neural ProgenitorCells(NPC)的基因芯片结果及NPC时期的RFX1ChIP-Seq数据,进行有关RFX1的分析,结果表明:RFX1结合位点富集在1,2,4,5,7,9,11染色体上,Y染色体上最少,其他染色体上比较均衡;在基因组中结合位点分布区域主要在基因的promoter区域,约有53.2%,其次是intergentic,占22.5%,body区域,占13.1%,enhancer区域,占11.2%.说明RFX1是以结合在基因的promoter区为主要形式对目的基因进行调控.同时在DAVID数据库中用生物信息学方法探索了RFX1靶基因的生物学功能分类.     

哺乳动物细胞高效表达系统研究进展

哺乳动物细胞高效表达系统是生物制药工业中十分关键的环节,而表达载体和宿主细胞又是哺乳动物细胞表达系统的两个重要组成部分.文章较详细综述了通过目的基因整合位点的优化、增加目的基因拷贝数、提高目的基因的转录和翻译水平等构建哺乳动物细胞高效表达载体的研究进展.同时,为使宿主细胞更好地适应工业化大规模培养要求,对通过抗凋亡、细胞周期调控、糖基化、细胞增殖控制技术和多基因代谢等细胞代谢工程对其进行改造的研究进展也作了介绍.     

锡掺杂金红石TiO2纳米棒的低温快速合成及其光电性能研究

采用水热合成法,在较低温度下通过仅引入Sn⁴⁺合成了金红石型棒状TiO₂纳米晶。X射线衍射仪（XRD）及透射电子显微电镜（TEM）对不同Sn4+掺杂比例粉体的晶型及形貌的分析表明,Sn⁴⁺能促进TiO₂由颗粒状的锐钛矿相向棒状的金红石型的转变,棒状纳米晶的形成是纳米颗粒沿着（110）晶面发生定向生长的结果,且形貌转变与晶相转变伴随发生。掺杂样品的光电转换性能研究结果表明,薄膜电极的光电转换效率与材料的晶相组分及其形貌之间有一定的关系,掺杂比例达到0.75%以后,样品的晶相组分及形貌不再随掺杂比例的增大而发生变化,进而光电转换效率不再变化。