核壳结构AgInS2@ZnS量子点的合成及荧光性能

合成了一种新型核壳结构的AgInS₂@ZnS量子点并研究了其荧光性能. AgInS₂@ZnS的合成包括以变性牛血清白蛋白(dBSA)为稳定剂水相法构建AgInS₂核以及形成ZnS壳两部分. 考察了配方和工艺条件对该量子点荧光性能的影响, 并采用X射线粉末衍射(XRD)等手段对制备的纳米粒子进行了表征. 结果表明, AgInS₂@ZnS是一种核壳结构的纳米物质, 其粒径介于5~7 nm之间, 荧光量子产率达35.3%.     

微流动注射进样-加热雾室-等离子体质谱测定血清中的铂

开发了一种基于雾化室加热的微流动注射进样系统,并用于血清中Pt的测定。该进样系统由微量毛细管雾化器、加热微型雾化室、八通道十六孔多功能旋转阀、蠕动泵和注射泵组成。研究了雾化室尺寸、加热温度和采样环体积对信号强度的影响。当雾化室内径为9 mm、加热段长度为6 cm,雾化室温度90 ℃,采样环体积为5 μL时,195Pt的信号强度提高了2.31倍,同时信号精密度从5.1%降至2.2%,并得到峰形良好的信号峰。该进样系统的试样消耗小、灵敏度和检出限均优于常规进样系统。10次测定10 μg/L的Pt标准溶液和血清样品溶液,峰高的RSD分别为2.9%和3.3%。该进样系统测得10个血清中的Pt含量与常规进样系统的测试结果无显著差异,在样品量稀少的情况下具有良好的应用价值。     

Label‐ and modification‐free‐based in situ selection of bovine serum albumin specific aptamer

Systematic evolution of ligands by exponential enrichment is a traditional approach to select aptamer, which has a great potential in biosensing field. However, chemical modifications of DNA library or targets before selection might block the real recognition and binding sites between aptamers and their targets. In this study, a label‐ and modification‐free‐based in situ selection strategy was developed to overcome this limitation. The strategy is an attempt to screen bovine serum albumin aptamers according to the principle of electrophoretic mobility shift assay, and allowed single‐stranded DNA sequence to be fully exposed to interact with bovine serum albumin which was mixed with the agarose gel beforehand. After eight rounds of selection, specific aptamer with low dissociation constant (K_d) value of 69.44 ± 7.60 nM was selected and used for subsequent establishment of fluorescence biosensor. After optimization, the optimal aptasensor exhibited a high sensitivity toward bovine serum albumin with a limit of detection of 0.24 ng/mL (linear range from 1 to 120 ng/mL). These results indicated that the label‐ and modification‐free‐based in situ selection strategy proposed in this work could effectively select specific aptamer to develop aptasensor for sensitive detection of bovine serum albumin or other targets in actual complicated samples.     

Protein interactions with negatively charged inorganic surfaces

Protein adsorption on charged inorganic solid materials has recently attracted enormous interest owing to its various possible applications, including drug delivery and biomaterial design. The need to combine experimental and computational approaches to get a detailed picture of the adsorbed protein properties is increasingly recognised and emphasised in this review. We discuss the methods frequently used to study protein adsorption and the information they can provide. We focus on model systems containing a silica surface, which is negatively charged and hydrophilic at physiological pH, and two contrasting proteins: bovine serum albumin (BSA) and lysozyme (LSZ) that are both water soluble. At pH 7, BSA has a net negative charge, whereas LSZ is positive. In addition, BSA is moderately sized and flexible, whereas LSZ is small and relatively rigid. These differences in charge and structural nature capture the role of electrostatics and hydrophobic interactions on the adsorption of these proteins, along with the impact of adsorption on protein orientation and function. Understanding these model systems will undoubtedly enhance the potential to extrapolate our knowledge to other systems of interest.     

Thermal denaturation of bovine serum albumin and its oligomers and derivativespH dependence

In a previous paper, we report a preliminary DSC study on bovine (BSA) and human (HSA) serum albumins. However, at accurate HPLC analysis the commercial proteins show three peaks: Fraction V-I, probably globulins (as declared by the producers), Fraction V-II (about 15–18% of the product) and Fraction V-III that represents pure BSA or HSA. A hypothesis is that the Fraction II is a covalent dimer, or trimer or a mixture of both, generated during the scalf-life of the commercial product. Denaturation enthalpies of the purified Fraction V-III and Fraction V-II of BSA, have been determined calorimetrically, at changing thepH, and the results of both compared with those obtained on the untreated protein. Few calorimetric experiments have been also carried on a BSA monomer derivative with sulphidril group protected. Computer program have been developed for the deconvolution of exo- and endothermic effects and for the analysis of thermal denaturation profiles.     

催化动力学褪色光度法测定痕量钒

基于磷酸和棉红在沸水发色条件下反应生成的产物在钒（Ⅴ）催化下被ＫＢｒＯ３氧化而建立了一个测定超痕量钒的新方法,方法选择性好;测定范围是０．００－０．７０μｇ／Ｌ,检测出限量７．３＊１０＾－１２ｇ／ｍＬ,方法用于芹菜、人体血清和井水中超痕量钒的测定,获得了满意结果。     

3-[二(羧甲基)氨甲基]-1, 2-二羟基蒽醌与蛋白质作用的研究

在pH4.1的缓冲溶液中,研究3-[二(羧甲基)氨甲基]-1,2-二羟基蒽醌(AFB)与牛血清蛋白(BSA)结合反应,相互生成的紫色的配合物。采用UV光谱法,测得此配合物的最大吸收峰值为510nm,与试剂本身相比较红移90nm。表观摩尔吸光系数ε=1.2474×10^4mol^-^1.cm^-^1.L,最大结合数n=7,表观结合常数K~c=3.85×10^6。研究发现,AFB与BSA之间主要是以分子之间的静电引力结合,认为该反应符合Scatchard模型。离子强度对结合反应有显著的影响。     

Detection and identification of the designer benzodiazepine flubromazepam and preliminary data on its metabolism and pharmacokinetics

The appearance of pyrazolam in Internet shops selling ‘research chemicals’ in 2012 marked the beginning of designer benzodiazepines being sold as recreational drugs or ‘self medication’. With recent changes in national narcotics laws in many countries, where two uncontrolled benzodiazepines (phenazepam and etizolam), which were marketed by pharmaceutical companies in some countries, were scheduled, clandestine laboratories seem to turn to poorly characterized research drug candidates as legal substitutes. Following the appearance of pyrazolam, it comes with no surprise that recently, flubromazepam (7‐bromo‐5‐(2‐fluorophenyl)‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one), a second designer benzodiazepine, was offered on the market. In this article, this new compound was characterized using nuclear magnetic resonance, gas chromatography‐mass spectrometry (GC–MS), liquid chromatography–mass spectrometry (LC–MS/MS) and liquid chromatography quadrupole time‐of‐flight MS (LC–Q–ToF–MS). Additionally, a study was carried out, in which one of the authors consumed 4 mg of flubromazepam to gain preliminary data on the pharmacokinetic properties and the metabolism of this compound. For this purpose, serum as well as urine samples were collected for up to 31 days post‐ingestion and analyzed applying LC–MS/MS and LC–Q‐ToF‐MS techniques. On the basis of this study, flubromazepam appears to have an extremely long elimination half‐life of more than 100 h. One monohydroxylated compound and the debrominated compound could be identified as the predominant metabolites, the first allowing a detection of a consumption for up to 28 days post‐ingestion when analyzing urine samples in our case. Additionally, various immunochemical assays were evaluated, showing that the cross‐reactivity of the used assay seems not to be sufficient for safe detection of the applied dose in urine samples, bearing the risk that it could be misused in drug‐withdrawal settings or in other circumstances requiring regular drug testing. Furthermore, it may be used in drug‐facilitated crimes without being detected. Copyright © 2013 John Wiley & Sons, Ltd.     

血清微量元素与儿童少年身高生长的相关研究

报道了6-18岁在校学生身高生长突增的情况以及身高突增期前后血清中Ca、Mg、Zn、Fe、Cu、Mn、Se、Pb8种元素含量的变化。结果表明，女生身高生长突增开始、达到高峰及突增结束年龄均早于男生约2年。在身高生长的三个阶段，血清Ga、Mn、Cu、Se、Pb含量都有显著或极显著差异。血清Ca在身高突增期以后水平较低，血清Mn在身高突增期以前水平较低，血清Cu在身高突增期以前水平较高，血清Se、Pb则呈渐减趋势。而两性间除血清Cu女生高于男生外，其它各元素均无显著性羌异。     

牛血清蛋白对手性物质的毛细管电泳拆分

采用聚氧乙烯涂层毛细管柱，以牛血清蛋白(BSA)为手性添加剂，运用毛细管电泳电导检测对手性药物沙丁胺醇和多沙唑嗪以及DL-组氨酸、色氨酸、苏氨酸进行拆分。考察了涂层柱的稳定性和重现性。对影响手性分离的主要因素：缓冲溶液的浓度和酸度、BSA的浓度、有机溶剂的种类和浓度以及分离电压进行了系统的研究。结果表明：在选择的最佳实验条件下，各对映异构体在22min内得到基线分离。