高效毛细管电泳在核酸、蛋白质分析中的新进展

高效毛细管电泳以其分离效率高，分析速度快，样品和试剂用量少，易于实现自动化等优点，在核酸、蛋白质等生物样品的分析方面发挥着重要的作用并具有巨大的潜力。本文介绍了近两年来高效毛细管电泳技术的进展，特别是PCR／CE、CE／MS以及电泳芯片技术等方面的新发展，并综述了高效毛细管电泳在核酸、蛋白质分析方面的应用，同时对其前景进行了展望。     

中药复方“清开灵”注射液中胆酸类物质的液相色谱/质谱/质谱分析

采有液相色谱／质谱／质谱法,通过保留时间、分子量和二级质谱的信息对复方“清开灵”注射液中的胆酸、去氧胆酸和鹅去氧胆酸进行了定性;建立了内标法对复方中相对含量较大的胆酸的定量分析方法;结果表明胆酸在875ng/L-140μg／L范围内线性良好,线性相关系数R^2=0.9999;RSD=2.4%。该方法样品处理简单,选择性好,灵敏度高。对中药的质量控制具有重要的意义。     

碳纳米管修饰电极对多巴胺和肾上腺素的电分离及同时测定

研究了多巴胺 (DA)和肾上腺素 (EP)在多壁碳纳米管 (MWNT)修饰电极上的电化学性质 ,发现该修饰电极对神经递质DA和EP有显著的增敏和电分离作用。还原峰电位差达ΔEp=390mV ,可同时测定DA和EP。DA和EP的还原峰电流与其浓度分别在 2 .0× 10 -6～ 1.0× 10 -3 mol/L和 1.0× 10 -6～ 1.0× 10 -3 mol/L浓度范围内呈良好的线性关系 ;方法的检出限分别为 1× 10 -6mol/L和 5× 10 -7mol/L。由于抗坏血酸 (AA)在MWNT修饰电极上的氧化是不可逆的 ,因此利用还原峰进行测定 ,消除了AA对DA和EP的干扰     

高效液相色谱-核磁共振联用技术最新进展

介绍了ＨＰＬＣ－ＮＭＲ技术的最新发展状况,讨论了ＨＰＬＣ－ＮＭＲ技术在应用中面临的问题和解决方法,评述了ＨＰＬＣ－ＮＭＲ两种主要操作方式：连续流和驻流方式,并介绍了ＨＰＬＣ－ＮＭＲ技术的应用情况,最后对其今后的发展方向作了预测。     

毛细管电动色谱分离手性氨基酸及其在生物样品分析中的应用

建立了MEKC法分离丙氨酸(Ala)、谷氨酸(Glu)和天门冬氨酸(Asp)三对手性氨基酸,并对大鼠正常组和白内障组晶体和血清中DAla、LAla、DGlu、LGlu、DAsp和LAsp进行定量分析。利用FITC柱前衍生,以β环糊精(βCD)作为手性添加剂,激光诱导荧光检测(LIF),优化电泳条件为气压进样5s,分离温度25℃,分离电压为20kV,运行缓冲溶液为40mmol/L硼砂缓冲溶液(pH9.3),其中包含50mmol/LSDS和13mmol/LβCD。考察了硼砂缓冲溶液浓度、pH值、分离电压、β环糊精浓度对分离的影响。在优化电泳条件下,上述3种氨基酸对映体均得到基线分离,并可对大鼠的晶体和血清进行定量分析。本方法操作简单,检测灵敏度高,可用于药品质量监测以及生物样品的分析。     

二维硫化钼基原子晶体材料的化学气相沉积法制备及其器件

二维过渡族金属硫属化合物因其带隙具有强烈的层数依赖性而在电子器件方面具有广泛的应用前景.其中单层二硫化钼(MoS₂)是该系列材料中最典型的一种直接带隙半导体,它具有优异的光、电、磁、热和力学性能.二维MoS₂有望在光电探测、光伏器件、场效应晶体管、存储器件、谷电子和自旋器件、温差电器件、微纳机电器件和系统等方面得以广泛应用.化学气相沉积(CVD)法已成为制备二维过渡族金属硫属化合物如MoS₂、MoSe₂、WS₂和WSe₂等原子层薄膜的主要手段,尤其科学界利用CVD法对二维MoS₂材料进行了深入的制备探索,通过该方法制备的MoS₂薄膜在电子和光电器件方面已经有广泛研究.本文将从二维MoS₂的基本物性出发,详细介绍CVD法制备MoS₂的各种工艺过程,如热分解硫代硫酸盐法、硫化Mo(MoO_3-x)薄膜制备法、MoO_3-x粉体与硫属前驱体气相合成法和钼箔表面直接硫化法,并介绍了基于MoS₂的二维异质结构筑方法.在制备材料的基础上,详细阐述了二维MoS₂在场效应晶体管、光电探测器、柔性电子器件以及异质结器件方面的应用,并展望了二维材料在半导体器件中的应用前景.     

Structure–activity relationships of eight <Emphasis Type="Italic">ent</Emphasis>-kaurene diterpenoids from three <Emphasis Type="Italic">Isodon</Emphasis> plants

Eight ent-kaurene diterpenoids were isolated from three Isodon plants, Isodon excisoides (Sun ex C. H. Hu) C. Y. Wu et H. W. Li, Isodon weisiensis C. Y. Wu, and Isodon racemosa (Hemsl.) Hara. Their cytotoxicities were tested by SRB assay against four human tumor cell lines, HepG2, Tb, HO-8910 and SGC-7901. The DNA damage degrees on their Hep G2 cells were evaluated by Comet assay. The results showed that ent-kaurene diterpenoids were selectively toxic against these four tumor cell lines. Weisiensic C had the lowest cytotoxicity against four cell lines and degree of DNA damage on the Hep G2 cell line. Leukamenin E and Glaucocalyxin A had similar IC₅₀ values and also induced a similar degree of DNA damage. The cytotoxicity and degree of DNA damage of eight ent-kaurene diterpenoids on Hep G2 was in the order Leukamenin E > Glaucocalyxin A > Wangzaozin A > Kamebanin > Macrocalyxin D > Weisiensin B > Excisanin K > Weisiensic C. The structure–activity relationships indicated that there was some correlation between the substituents and their structures of ent-kaurene diterpenoids and their activities on Hep G2 cells.     

Altitudinal trends of leaf δ13C follow different patterns across a mountainous terrain in north China characterized by a temperate semi‐humid climate

Many studies have documented that the δ¹³C values of plants increase with altitude both on a global scale and locally in humid climates, while in semi‐arid areas the opposite trend has been found. The study reported herein was conducted in a mountainous area of China characterized by a temperate semi‐humid climate. The δ¹³C values of C₃ species do not exhibit a consistent variation along an altitudinal gradient and the observations suggest that the pattern of increasing δ¹³C with altitude cannot be generalized. In the study area, in addition to environmental factors such as changing air pressure and light, the interaction between temperature and plant water balance determines the δ¹³C‐altitude variations in C₃ plants. The δ¹³C of the leaves of C₄ plants is found to increase with altitude with a mean gradient of 0.9‰/km. The altitudinal trend of C₄ plants is attributed to the combined influences of water availability and other factors rather than temperature. Copyright © 2010 John Wiley & Sons, Ltd.     

A Novel in Situ Oxidization-Sulfidation Growth Route via self-Purification Process to β-In2S3 Dendrites

A novel in situ oxidization-sulfidation growth route via a self-purification process has been developed to synthesize β-In₂S₃ dendrites. To our best knowledge, this is the first example to prepare dendrites of III-VI compounds, which are expected to show particular physical properties. The X-ray analysis (EDXA), X-ray photoelectron spectra (XPS), Raman spectrum and optical properties of β-In₂S₃ dendrites have also been investigated. It is found that the product is pure In₂S₃ and shows the strong quantum confinement of the excitonic transition expected for the In₂S₃ dendrites.