葡萄糖在聚对苯二胺/铜修饰电极上的电化学行为及测定

在静态法合成聚对苯二胺纳米片的基础上,经一步水热将铜微球均匀锚定于其上,成功合成了具有良好导电性、大比表面积、大孔径和孔容的铜/聚对苯二胺(Cu/Pp PD)复合物,其独特的结构有利于电子的转移、活性位点的充分利用以及反应物、电解质等的输运。复合物对葡萄糖氧化表现出很高的电催化活性,在最优测试条件下,所构建的葡萄糖无酶传感器响应时间短(达到稳定电流的95%所需时间小于3 s)、线性范围宽(0.003~6.44 mmol/L)、灵敏度高(929μA·mmol-1·L·cm-2)、检出限低(4.48×10-7mol/L)、重现性和选择性好,对血清样品进行检测,回收率为99.5%~101.1%。所制备Cu/Pp PD复合物能实现对葡萄糖的简单、快速、灵敏、准确无酶检测,在临床医学上糖尿病人的早期诊断和治疗监测领域具有很好的应用前景。     

纳米金-还原氧化石墨烯修饰葡萄糖氧化酶传感器的制备及其电流法检测饮料中的葡萄糖

利用纳米金(Au NPs)与还原氧化石墨烯(rGO)复合纳米材料制备了葡萄糖氧化酶生物传感器并用于饮料中葡萄糖含量的检测。将壳聚糖作为还原剂及稳定剂,通过一步法合成了Au NPs-rGO复合材料,并通过物理吸附固定葡萄糖氧化酶(GOx)来制作GOx生物传感器。该传感器在磷酸盐缓冲溶液(0.1 mol/L,p H6.0)中,-0.45 V(vs.Ag/Ag Cl)电位下电流法检测葡萄糖含量,线性检测范围为0.01~0.88 mmol/L,灵敏度为22.54μA·mmol-1·L·cm-2,检出限为1.01μmol/L,且表观米氏常数为0.497 mmol/L。该传感器用于多种饮料中葡萄糖含量的直接检测,结果满意。     

胰岛素联合沙格列汀降糖疗效及安全性的研究

目的评估胰岛素联合沙格列汀治疗2型糖尿病的有效性和安全性。方法回顾性对照研究50例2型糖尿病患者胰岛素加用沙格列汀或阿卡波糖治疗(48±8)周后血糖水平和血糖波动等指标的变化。结果治疗(48±8)周后,两组血糖、Hb A1c、MAGE均明显下降(P均≤0.001),其中沙格列汀组MAGE的降幅明显大于阿卡波糖组(P=0.024),胃肠道不良反应发生率显著低于阿卡波糖组。结论沙格列汀联合胰岛素具有更强的控制血糖波动的疗效,胃肠道不良反应发生率更低。     

Therapeutic Potential of Highly Selective A3 Adenosine Receptor Ligands in the Central and Peripheral Nervous System

Ligands of the G_i protein-coupled adenosine A₃ receptor (A₃R) are receiving increasing interest as attractive therapeutic tools for the treatment of a number of pathological conditions of the central and peripheral nervous systems (CNS and PNS, respectively). Their safe pharmacological profiles emerging from clinical trials on different pathologies (e.g., rheumatoid arthritis, psoriasis and fatty liver diseases) confer a realistic translational potential to these compounds, thus encouraging the investigation of highly selective agonists and antagonists of A₃R. The present review summarizes information on the effect of latest-generation A₃R ligands, not yet available in commerce, obtained by using different in vitro and in vivo models of various PNS- or CNS-related disorders. This review places particular focus on brain ischemia insults and colitis, where the prototypical A₃R agonist, Cl-IB-MECA, and antagonist, MRS1523, have been used in research studies as reference compounds to explore the effects of latest-generation ligands on this receptor. The advantages and weaknesses of these compounds in terms of therapeutic potential are discussed.     

Analysis of the Structure of the Bands in the IR Spectrum of β-D Glucose by the Regularized Method of Deconvolution

Deconvolution of the IR absorption spectrum of -D glucose in the spectral range 1500–450 cm^–1 has been carried out. The results of the deconvolution were compared with the IR and Raman spectra recorded at room and low temperatures and with the data obtained by theoretical calculations for the frequencies of the normal vibrations of the -D glucose molecule in the crystalline state. It is shown that deconvolution of the IR spectra recorded at room temperature makes it possible to separate the bands observed experimentally only at a very low temperature of the sample and a number of components that were not resolved earlier. The number of bands separated on deconvolution of the IR spectra of -D glucose in the spectral range 1500–450 cm^–1 is more than twice the number of visible absorption maxima in the usual spectrum. The results of deconvolution of the IR spectrum of -D glucose are in good agreement with the data of theoretical calculations for the frequencies of the normal vibrations of the -D glucose molecule in the crystalline state. The existence of the factor-group (Davydov) splitting of a number of frequencies of the nondegenerate fundamental vibrations of molecules in a crystal cell has been revealed in the IR spectrum of -D glucose. It was concluded that the model of an isolated molecule is insufficient for detailed theoretical interpretation of the vibrational spectra of carbohydrates.     

微量元素硒和糖耐量异常

非胰岛素依赖型糖尿病（ＮＩＤＤＭ）已成为现代社会的主要疾病之一，尤其各种并发平给机体带来的致命后果使倍受重视。而预防的关键是，在耐量异常阶段发现并治疗，效果更佳。已发现在糖耐量异常（ＩＣＴ）时存在各种抗氧化缺陷，因此，硒（Ｓｅ）的抗氧化作用对ＩＧＴ可能有一定的疗效。     

13C isotope effects on 1H chemical shifts: NMR spectral analysis of 13C‐labelled D‐glucose and some 13C‐labelled amino acids

The one‐ and two‐bond ¹³C isotope shifts, typically ?1.5 to ?2.5 ppb and ?0.7 ppb respectively, in non‐cyclic aliphatic systems and up to ?4.4 ppb and ?1.0 ppb in glucose cause effects that need to be taken into account in the adaptive NMR spectral library‐based quantification of the isotopomer mixtures. In this work, NMR spectral analyses of some ¹³C‐labelled amino acids, D ‐glucose and other small compounds were performed in order to obtain rules for prediction of the ¹³C isotope effects on ¹H chemical shifts. It is proposed that using the additivity rules, the isotope effects can be predicted with a sufficient accuracy for amino acid isotopomer applications. For glucose the effects were found strongly non‐additive. The complete spectral analysis of fully ¹³C‐labelled D ‐glucose made it also possible to assign the exocyclic proton signals of the glucose. Copyright © 2009 John Wiley & Sons, Ltd.     

Self‐Assembly of Ag6 Clusters into Nanowires for Nonenzymatic Electrochemical Sensing of Glucose

Self‐assembly of metal nanoclusters into 3D ordered superstructures and the exploration of their electrochemical properties are highly significant for fundamental research and practical application. In this study, atomically precise Ag₆(NALC)₅ nanoclusters are successfully synthesized and their structure is determined carefully. It is interesting that the prepared Ag₆(NALC)₅ nanoclusters can be self‐assembled into ultrafine nanowires, long ribbons, and finally 3D porous network in the mixed solution of water and ethanol, which can be attributed to the solvent polarity, static electricity interaction between ligands, and the possible Van der Waals attractions. Such assembly phenomenon lays a foundation for the future fabrication of silver clusters‐based nanodevices. In addition, the synthesized silver nanoclusters can be used for electrochemical sensing of glucose with high detection sensitivity, selectivity, and low limit of detection. This work is expected to be helpful for the synthesis of atomically precise metal nanoclusters and their applications in fabrication of nanodevices for chemical sensors.     

Microbiosensor based on glucose oxidase and hexokinase co-immobilised on platinum microelectrode for selective ATP detection

ATP determination is of great importance since this compound is involved in a number of vital biological processes. To monitor ATP concentration levels, we have developed a microbiosensor based on cylindrical platinum microelectrode, covered with a layer of poly-m-phenylendiamine (PPD), and layer of co-immobilised glucose oxidase and hexokinase. Conditions for biosensor measurement of ATP (pH, Mg²⁺ and substrates concentration) in vitro and microbiosensor characteristics such as sensitivity, selectivity, reproducibility, storage stability were studied and optimized. Under optimal conditions the microbiosensor can measure ATP concentrations down to a 2.5 μM detection limit with response time about 15 s. Interferences by electroactive compounds like biogenic amines and their metabolites, ascorbic acid, uric acid and l-cystein are rejected in general by the PPD layer. The microbiosensor developed is insensitive to ATP analogues (or substances with similar structure), such as ADP, AMP, GTP and UTP, too. It can be used for ATP analysis in vitro in the reactions consuming or producing macroergic triphosphate molecules to study kinetics of the process and in drug design concerning development of inhibitors specific to target kinases and others target enzymes.