Carbon nanotube–polyaniline composites

The last decade has seen a growing interest in hybrid electrically conducting nanocomposites. This article aims to provide a detailed overview of the present status of research in carbon nanotube–polyaniline (CNT/PANI) composites, from processing to structural and property evaluations. CNT/PANI are synthesized by electrochemical and chemical processing. When chemical methods are used, the main challenge is to obtain processable CNT/PANI in the emeraldine salt (ES) form composites. Stable dispersions of ES–CNT in organic media are prepared using the post doping method, inverse emulsion polymerization, or ex situ polymerizations. On the contrary, stable water dispersions of CNT/ES are prepared using hydrophilization of a preformed CNT/ES composite, direct synthesis of micelle–CNT hybrid templates, interfacial polymerization, covalent functionalization of CNT with a water soluble polymer, or using electrostatic interactions between two oppositely charged ES and CNT aqueous colloids. Moreover, the strategies for the synthesis of ternary CNT/PANI composites incorporating noble metal nanoparticles, metal oxide, or graphene sheets are also presented and analyzed in depth. Finally, we give a review of potential applications, including chemical sensors, capacitors, fuel cells and electronic devices.     

Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: Studies on the essential oil and polar extracts

We investigated the metabolic profile and biological activities of the essential oil and polar extracts of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco collected in south Portugal. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that oxygen-containing monoterpenes was the principal group of compounds identified in the essential oil. Camphor (40.6%) and fenchone (38.0%) were found as the major constituents. High-performance liquid chromatography with diode array detection (HPLC–DAD) analysis allowed the identification of hydroxycinnamic acids (3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids) and flavones (luteolin and apigenin) in the polar extracts, with rosmarinic acid being the main compound in most of them. The bioactive compounds from L. pedunculata polar extracts were the most efficient free-radical scavengers, Fe²⁺ chelators and inhibitors of malondialdehyde production, while the essential oil was the most active against acetylcholinesterase. Our results reveal that the subspecies of L. pedunculata studied is a potential source of active metabolites with a positive effect on human health.     

β-asarone对Aβ1-42激活的ACM所致PC12细胞损伤的保护作用研究

目的：探讨不同浓度β-淀粉样蛋白（Aβ1-42）激活的星形胶质细胞条件培养液（ACM）对PC12细胞存活率及脑源性神经营养因子（BDNF）、乙酰胆碱酯酶（AChE）蛋白表达的影响,以及β-细辛醚（β-asarone）的保护作用。方法：首先,将对数生长期的PC12细胞随机分为正常对照组、ACM（Aβ1-42 3.3 μmol/L）组、ACM（Aβ1-42 10 μmol/L）组、ACM（Aβ1-42 30 μmol/L）组,分别采用实时无标记动态细胞分析技术（Real Time Cell Analysis, RTCA）和MTT法检测各组PC12细胞的存活率,Western blot检测PC12细胞BDNF、AChE蛋白的表达;其次,将对数生长期的PC12细胞随机分为正常对照组、ACM（Aβ1-42 10 μmol/L）组、β-asarone（18.5、55.5、166.7 μg/mL）组,RTCA法检测PC12细胞存活率的改变,Western blot检测PC12细胞BDNF、AChE蛋白表达的变化。结果：ACM作用24 h,各组PC12细胞存活率无统计学差异（P>0.05）,ACM作用36 h,ACM（Aβ1-42 10 μmol/L）组、ACM（Aβ1-42 30 μmol/L）组PC12细胞存活率显著降低(P<0.01);BDNF、AChE蛋白表达随Aβ1-42 浓度增加显著升高(P<0.05或P<0.01);β-asarone(18.5、55.5、166.7 μg/mL)能显著提高PC12细胞的存活率,β-asarone(55.5、166.7 μg/mL)组AChE表达相比于模型组显著下降(P<0.05或P<0.01),β-asarone(55.5 μg/mL)组与模型组比较BDNF表达增加(P<0.05)。结论：β-asarone能抑制AChE的上调,对BDNF的表达有促进作用,提示β-asarone对神经元细胞有一定的保护作用。     

Dual effect of free and liposomal forms of phenolic lipids on the activity of GPI-anchor-deprived acetylcholinesterase from erythrocytes

The effect of free and liposomal forms of phenolic lipids isolated from rye grains, cashew nut-shell liquid (CNSL) from Anacardium occidentale, and Merrulius tremellosus fruit body on the glycosyl-phosphatidylinositol (GPI)-anchor-deprived erythrocyte-ghost acetylcholinesterase activity was studied. It was shown that the observed effect distinctly depends on the form of the phenolic lipids available for interaction with the enzyme. The free form of the phenolic lipids decreased the enzymatic activity of GPI-anchor-deprived acetylcholinesterase less than the acetylcholinesterase anchored in erythrocytes ghosts, whereas the same phenolic lipids present in the medium in liposomal form, increased it.     

基于多孔碳球修饰硼掺杂金刚石电极的 甲基对硫磷检测

目的 研究甲基对硫磷检测的快速检测方法。方法 用多孔碳球材料修饰硼掺杂金刚石(BDD)电极,将乙酰胆碱酯酶（AChE）固定在修饰电极表面制得酶传感器,用于甲基对硫磷的检测。对所制备的酶传感器进行电化学表征,对实验参数进行优化。结果 底物氯化乙酰胆碱的产物在AChE/BDD电极和AChE/多孔碳球/BDD电极上的氧化峰电流分别为0.4930μA和1.102μA,峰电流提高了123.53%。在AChE/多孔碳球/BDD电极上,建立抑制率与甲基对硫磷浓度的负对数的对应关系,在浓度范围10-10~10-7g/L内呈良好的线性关系,线性方程为A(%)=-13.20297x 148.375(%),相关系数R2为0.9985。按抑制率为10%计算检出限为3.02×10-12 g/L。对实际样品黄瓜汁进行检测,样品回收率为92.60%~102.00%。结论 此方法简单、快速、灵敏度高,适合用于实际样品中的甲基对硫磷残留分析。     

梭曼与乙酰胆碱酯酶(AChE)受体的对接研究

根据梭曼与AChE体系的对接要求,对CVFF力场中P—F键的参数进行了修改和补充。之后运用新建的力场参数,对梭曼与AChE进行了对接研究,并实现了应用量子化学／分子力学方法ONIOM(B3LYP／6—31G(d)／／UFF)对大分子体系的计算研究。分子力学对接研究表明,新参数与原CVFF力场有较好的一致性,可以完全适应于所研究的体系。同时,通过计算得到10个低能量构象,其中两个最低构象的结构与ONIOM计算结果一致,这也表明对于研究大分子与小分子对接等过程特别是构象搜寻方面,CVFF力场仍然可以得到比较合理的结果。但ONIOM计算也显示出分子力场方法在处理受体与底物之间易发生化学反应或有化学反应产生趋势的体系时会产生误差,对强氢键的估计不足将限制其应用范围。     

鲅鱼脑组织AChE的分离纯化及某些生化性质

采用亲和层析法对鲅鱼[Scomberomorus niphonius(Cuvier)]脑组织的胆碱酯酶[acetylcholinesterase(AChE),EC 3.1.1.7]进行分离纯化,然后对其进行底物特异性、过量底物抑制效应和抑制剂选择性检验。结果证实:该酶为乙酰胆碱酯酶(AChE),其最大比活力为297.82μmol/(min.mg),最佳pH范围在7.0~8.0之间,最佳温度为30℃。此酶经过SDS PAGE呈一条带,表明其纯度达电泳纯。     

Immunohistochemical and histochemical findings favoring the occurrence of autocrine/paracrine as well as nerve-related cholinergic effects in chronic painful patellar tendon tendinosis

The pathogenesis of the pain in patellar tendon tendinosis ("jumper's knee") is unclear. We have recently presented new information about the sensory nervous system in the human patellar tendon, but there is very little information regarding the possible occurrence of a cholinergic system in this tendon. In the present study, specimens of pain-free normal tendons and chronically painful tendinosis tendons were examined by different immunohistochemical and histochemical methods. Antibodies against the M(2) receptor, choline acetyltransferase (ChAT), and vesicular acetylcholine transporter (VAChT) were applied, and staining for demonstration of activity of acetylcholinesterase (AChE) was also utilized. It was found that immunoreactions for the M(2) receptor could be detected intracellularly in both blood vessel cells and tenocytes, especially in tendinosis specimens. Furthermore, in the tendinosis specimens, some tenocytes were seen to exhibit immunoreaction for ChAT and VAChT. AChE reactions were seen in fine nerve fibers associated with small blood vessels in both the normal control tendons and the tendinosis tendons. The observations suggest that there is both a nerve related and a local cholinergic system in the human patellar tendon. As ChAT and VAChT immunoreactions were detected in tenocytes of tendinosis tendons, these cells might be a source of local acetylcholine (Ach) production. As both tenocytes and blood vessel cells were found to exhibit immunoreactions for the M(2) receptor, it is likely that both of these tissue cells may be influenced by ACh. Thus, in conclusion, there appears to be an upregulation of the cholinergic system, and an occurrence of autocrine/paracrine effects in this system, in the tendinosis patellar tendon.     

果菜中常用有机磷农药快速检测方法的研究

利用有机磷农药能抑制胆碱酯酶酶促反应的机理,本文提出了两种快速测定果菜中有机磷农药残留的方法,既可以根据颜色进行半定量的判断,也可以根据反应液△pH值进行定量的测定.此种方法简便,快速,可行,适合于市场管理部门,家庭及个人使用.