氟喹诺酮类抗生素与赤藓红的共振瑞利散射光谱研究及其分析应用

在Ph4.0～5.0的BR缓冲介质中,赤藓红(Ery)与莫西沙星(MXFX)和加替沙星(GTF)等氟喹诺酮类抗生素(FLQs)相互作用形成1:1离子缔合物,体系反应导致共振瑞利散射(RRS)显著增强并出现新的RRS光谱.两种药物的反应产物具有相似的光谱特征,最大散射波长位于568nm处,并在342nm和378nm处有2个较小的散射峰.在342nm处一定浓度的抗生素与散射增强成正比,两种氟喹诺酮类药物的线性范围分别是0.02～2.7μg/mL(MXFX)和0.06～10.2μg/mL(GTF).据此建立了测定氟喹诺酮类药物的新方法,已用于胶囊和人尿液中的FLQs测定,并对反应机理和RRS增强的原因作了讨论.     

计算机与化学Origin软件在物理化学实验中的应用

物理化学实验数据处理类型分为直线型和曲线型。本文结合实例对每一类实验数据利用Origin软件作图并进行线性拟合、非线性拟合和分段拟合处理。最后得出运用Origin软件进行物理化学实验数据处理具有客观性和规范性、可以大大提高处理效率的结论。     

水产品中甲基汞测定的液相色谱-原子荧光光谱联用方法的改进

对本实验室前期建立的食品中甲基汞的液相色谱-原子荧光光谱联用测定方法进行了改进。采用无毒的半胱氨酸代替有毒试剂巯基乙醇作为流动相中的配位剂,流动相组成为5%(v/v)乙腈-1 g/L半胱氨酸-50 mmol/L乙酸铵水溶液,使汞化合物分离时间缩短至8 min。在优化条件下,甲基汞标准曲线的线性范围为1～50 μg/L,检出限(S/N=3)为0.3 μg/L。采用超声波辅助5 mol/L HCl提取样品中的甲基汞,提取液经C18固相萃取小柱净化后进样。鱼、虾、贝等不同种类水产动物样品以及水产类膳食样品的甲基汞加标回收率为89%～112%。对标准参考物质NIST1566b、BCR464和GBW10029以及英国食品分析水平评估计划(Food Analysis Performance Assessment Scheme, FAPAS)的罐装鱼肉样品(样品编号07115)的测定结果与参考物定值相符,验证了该方法的可靠性与准确性。本方法可满足食品中甲基汞检测的需要。     

荧光光谱法研究橙皮甙与牛血清白蛋白的相互作用

在pH7.40的Tris-HCl 缓冲体系中,采用荧光光谱技术研究了橙皮甙与牛血清白蛋白(BSA)的相互作用.随着温度升高,橙皮甙与BSA 的猝灭常数逐渐增加.实验表明:橙皮甙对BSA的荧光猝灭为动态猝灭过程.由热力学参数焓变(△H=70.71 kJ/mol)大于零和熵变[△S=316.29J/(mol·K)]大于零,...     

Vapor phase polymerization of 3,4‐ethylenedioxythiophene on flexible substrate and its application on heat generation

An oxidative chemical vapor phase polymerization process is applied to coat flexible polyethylene terephthalate (PET) fabrics with a uniform poly(3,4‐ethylenedioxythiophene) (PEDOT) film. This vapor phase polymerization method is a solventfree technique, which could yield a low resistance in the PEDOT‐coated PET fabric. The resistance as low as 52 Ω square^?1 is achieved. The polymerization conditions, such as the concentration of oxidant, reaction time, and temperature, have been systematically investigated. The coated fabric samples exhibit an increase in temperature when subjected to a fixed DC voltage. This result indicates a potential application of these PEDOT‐coated fabrics as electric heating materials. Copyright © 2009 John Wiley & Sons, Ltd.     

Reactions of a gold(I) thiolate complex [Au(Tab)(2)](2)(PF(6))(2) (Tab = 4-(trimethylammonio)benzenethiolate) with diphosphine ligands

Reactions of a gold(i) thiolate complex [Au(Tab)(2)](2)(PF(6))(2) (Tab = 4-(trimethylammonio)benzenethiolate) with equimolar 1,2-bis(diphenylphosphine)ethane (dppe), 1,3-bis-(diphenylphosphine)propane (dppp) or 1,4-bis-(diphenylphosphine)butane (dppb) in MeOH-DMF-CH(2)Cl(2) gave rise to three polymeric complexes [Au(2)(Tab)(2)(dppe)](2)(PF(6))(4)·2MeOH (1·2MeOH), [Au(2)(Tab)(2)(dppp)]Cl(2)·0.5MeOH·4H(2)O (2·0.5MeOH·4H(2)O), and [Au(4)(μ-Tab)(2)(Tab)(2)(dppb)](PF(6))(4)·4DMF (3·4DMF), respectively. Analogous reaction of 1 with dppb in DMF/C(2)H(4)Cl(2) produced one tetranuclear complex [Au(2)(μ-Tab)(Tab)(2)](2)Cl(4)·2DMF·4H(2)O (4·2DMF·4H(2)O). Complexes 1-4 were characterized by elemental analysis, IR spectra, UV-vis spectra, (1)H and (31)P{(1)H} NMR and single crystal X-ray analysis. Compounds 1 and 2 consist of [Au(Tab)](2) dimeric fragments that are bridged by dppe or dppp ligands to form a 1D linear chain extending along the a axis. For 3, each [Au(4)(Tab)(2)(μ-Tab)(2)] fragment is linked by a pair of dppb ligands to afford another 1D chain extending along the c axis. For 4, the four [Au(Tab)](+) fragments are linked by two Au-Au bonds and two doubly bridging Tab ligands to form a {[Au(Tab)](4)(μ-Tab)(2)} chair-like cyclohexane structure. Hydrogen-bonding interactions in 2 and 4 lead to the formation of interesting 2D hydrogen-bonded networks. The luminescent properties of 1-4 in solid state were also investigated.     

Palladium-catalyzed decarboxylative coupling of potassium nitrophenyl acetates with aryl halides

A palladium-catalyzed decarboxylative cross-coupling of potassium 2- and 4-nitrophenyl acetates with aryl chlorides and bromides has been developed. Because the nitro group can be readily converted to many other functional groups, the new reaction provides a useful method for the preparation of diverse 1,1-diaryl methanes and their derivatives.     

An advance in proline ligation

Native chemical ligation (NCL) is widely applicable for building proteins in the laboratory. Since the discovery of this method, many strategies have been developed to enhance its capability and efficiency. Because of the poor reactivity of proline thioesters, ligation at a C-terminal proline site is not readily accomplished. Here, we demonstrate that ligation at an N-terminal protein is feasible using the combined logic of NCL and metal-free dethiylation (MFD).     

Molybdenum nitride based hybrid cathode for rechargeable lithium-O2 batteries

Molybdenum nitride/nitrogen-doped graphene nanosheets (MoN/NGS) are synthesized and used as an alternative O(2) electrode for Li-O(2) batteries. In comparison with electrocatalysts proposed previously, this hybrid cathode exhibits a high discharge potential (around 3.1 V) and a considerable specific capacity (1490 mA h g(-1), based on carbon + electrocatalyst).     

Recording force events of single quantum-dot endocytosis

We applied force spectroscopy based on atomic force microscope (AFM) to demonstrate the possibility of measuring the interaction force between single quantum-dots (QDs) and living cells at single particle level under native conditions. In the force-distance cycle, we recorded the events of cellular uptake of single QDs and single QD detachment from the cell.