A Hybrid Membrane of Poly(vinyl alcohol) and Phosphotungstic Acid for Fuel Cells

Proton conducting membranes composed of phosphotungstic acid (PWA) and poly(vinyl alcohol) (PVA)were prepared. Conductivity and Fourier transform infrared spectrometer(FTIR) measurements show that most ofthe acid embedded are stable in the PVA matrix when the membrane is immerged in water or methanol solution atroom temperature. Conductivity of the composite membranes scatters around 10-3 S.cm-1 at room temperature.The methanol crossover through the membranes is about an order of magnitude lower than that through Nafion117 membrane.

Convenient Asymmetric Borane Reduction of Ketones Catalyzed by Simple Amino Alcohols and Corresponding Amino Acids

An asymmetric borane reduction of prochiral ketones catalyzed by simple amino alcohols and corresponding amino acids was examined to give alcohols with e.e. value up to 92% .

Study of Cross-Linking between Boric Acid and Different Types of Polyvinyl Alcohol Adhesive

Polyvinyl alcohol (PVA) is water-soluble polymer manufactured by the saponification of polyvinyl acetate. The physical properties and its specific application depend on the degree of hydrolysis. To enhance the properties of different hydrolyzed PVA grades, it is generally chemically modified with various cross-linkers. Here, different degree hydrolyzed PVA grades with enhanced properties were achieved by cross-linking with boric acid. These samples were then characterized by Differential Scanning Calorimetry (DSC) and Gel permeation chromatography (GPC). For further analysis a film of samples were prepared by casting on glass plate. The effects of amount of boric acid and degree of hydrolysis of PVA on performance properties like tensile strength, pencil hardness and thermal properties like glass transition temperature were studied. The results showed that by cross-linking there was an increase in mechanical strength and thermal property.

Reduced lysosomal acid lipase activity: A new marker of liver disease severity across the clinical continuum of non-alcoholic fatty liver disease?

Lysosomal acid lipase(LAL)plays a key role in intracellular lipid metabolism.Reduced LAL activity promotes increased multi-organ lysosomal cholesterol ester storage,as observed in two recessive autosomal genetic diseases,Wolman disease and Cholesterol ester storage disease.Severe liver steatosis and accelerated liver fibrosis are common features in patients with genetic LAL deficiency.By contrast,few reliable data are available on the modulation of LAL activity in vivo and on the epigenetic and metabolic factors capable of regulating its activity in subjects without homozygous mutations of the Lipase A gene.In the last few years,a less severe and non-genetic reduction of LAL activity was reported in children and adults with non-alcoholic fatty liver disease(NAFLD),suggesting a possible role of LAL reduction in the pathogenesis and progression of the disease.Patients with NAFLD show a significant,progressive reduction of LAL activity from simple steatosis to non-alcoholic steatohepatitis and cryptogenic cirrhosis.Among cirrhosis of different etiologies,those with cryptogenic cirrhosis show the most significant reductions of LAL activity.These findings suggest that the modulation of LAL activity may become a possible new therapeutic target for patients with more advanced forms of NAFLD.Moreover,the measurement of LAL activity may represent a possible new marker of disease severity in this clinical setting.

An Efficient One-step Methyl Esterification of Carboxylic Acid and Deacetylation of Alcohol under BF_3·OEt_2-MeOH

An efficient one-step methyl esterification of carboxylic acid and deacetylation of alcohol under BF3O·Et2-MeOH was developed.

Wet carbon-based solid acid/potassium permanganate as an efficient heterogeneous reagents for oxidation of alcohols under mild conditions

Wet carbon-based solid acid and potassium permanganate were used as new reagents for oxidation of alcohols to their corresponding aldehydes and ketones in heterogeneous mixtures. The experiments were done moderately at mild condition and high yields in suitable times were obtained.

Synthesis,Characterization and Structure of Chiral Amino Acids and Their Corresponding Amino Alcohols with Camphoric Backbone

Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.

A New Facile Route to Chlorination of Alcohols via Lewis Acid AlCl₃

Halogenated aluminates AlCl3, applied as efficient chlorination reagent for hydroxyl groups of substitution alcohols is described. Primary and secondary benzylic alcohols could be transformed into corresponding aromatic halides with almost complete conversion and unique selectivity. As chlorination reagent, AlCl3 has an incomparable advantage over others, such as low material cost, commercial availability as well as convenient product isolation.

Elevated Linoleic Acid (A Pro-Inflammatory PUFA) and Liver Injury in a Treatment Naive HIV-HCV Co-Infected Alcohol Dependent Patient

HIV and HCV co-infection is a unique disease condition, and medical management of such condition is difficult due to severity and systemic complications. Added with heavy alcohol drinking, risk of liver injury increases due to several pro-inflammatory responses that subsequently get involved with alcohol metabolism. Elevated levels of fatty acids have been reported both in viral infections as well as alcoholic liver disease though such investigations have not addressed the adverse event with dual viral infection of HIV and HCV along with heavy drinking. This case report of a patient with excessive alcohol drinking and first time diagnosis of HIV and HCV dual infection, elaborating concurrent alteration in Linoleic Acid (LA) levels and pro-inflammatory shift in ω-6/ω-3 ratio along with the elevations in liver injury markers. Elevated LA has been recently studied extensively for its role in alcoholic liver disease;and in the present case, we also found it to be clinically relevant to liver injury.

Omega-3 fatty acids for the treatment of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease(NAFLD) has been recognized as a major health burden.It is the most important cause of chronic liver disease and a major independent cardiovascular risk factor.Lacking a definite treatment for NAFLD,a specific diet and an increase in physical activity represent the most commonly used therapeutic approaches.In this review,major literature data about the use of omega-3 polyunsaturated fatty acids(n-3 PUFAs) as a potential treatment of NAFLD have been described.n-3 PUFAs,besides having a beneficial impact on most of the cardio-metabolic risk factors(hypertension,hyperlipidemia,endothelial dysfunction and atherosclerosis) by regulating gene transcription factors [i.e.,peroxisome proliferator-activated receptor(PPAR),PPAR,sterol regulatory element-binding protein-1,carbohydrate responsive element-binding protein],impacts both lipid metabolism and on insulin sensitivity.In addition to an enhancement of hepatic beta oxidation and a decrease of the endogenous lipid production,n-3 PUFAs are able to determine a significant reduction of the expression of pro-inflammatory molecules(tumor necrosis factor-and interleukin-6) and of oxygen reactive species.Further strengthening the results of the in vitro studies,both animal models and human intervention trials,showed a beneficial effect of n-3 PUFAs on the severity of NAFLD as expressed by laboratory parameters and imaging measurements.Despite available results provided encouraging data about the efficacy of n-3 PUFAs as a treatment of NAFLD in humans,welldesigned randomized controlled trials of adequate size and duration,with histological endpoints,are needed to assess the long-term safety and efficacy of PUFA,as well as other therapies,for the treatment of NAFLD and non-alcoholic steatohepatitis patients.It is worthwhile to consider that n-3 PUFAs cannot be synthesized by the human body and must be derived from exogenous sources(fish oil,flaxseeds,olive oil) which are typical foods of the Mediterranean diet,known for its beneficial effects in preventing obesity,diabetes and,in turn,cardiovascular events.According to these data,it is important to consider that most of the beneficial effects of n-3 PUFAs can also be obtained by an equilibrate nutrition program.

Indirect Determination of Ascorbic Acid with Ammonium Sulfate and Isopropyl Alcohol by Extraction-flotation of Copper

A new method of indirect determination of ascorbic acid(Vc) with ammonium sulfate and isopropyl alcohol by extraction-flotation of copper is studied in this paper. It shows that a small amount of Cu(Ⅱ) can be reduced to Cu( Ⅰ ) by Vc, then Cu(Ⅰ) reacted with the SCN-, which precipitated on the interface of isopropyl alcohol and H2O. A good linear relationship is observed between the flotation yield(E) of Cu( Ⅱ) and the amount of Vc. The detection limit for Vc is 1.76μg/mL. The method is simple, rapid (5 min), but suffers from little interference of common anions and cations. It has been successfully applied for the determination of Vc in fruits.

A novel application of horseradish peroxidase:Oxidation of alcohol ethoxylate to alkylether carboxylic acid

A novel application of horseradish peroxidase （HRP） in the oxidation of alcohol ethoxylate to alkylether carboxylic acid in the present of H2O2 was reported in this paper. We propose the mechanism for the catalytic oxidation reaction is that the hydrogen transfers from the substrate to the ferryl oxygen to form the α-hydroxy carbon radical intermediate. The reaction offers a new approach for further research structure and catalytic mechanism of HRP and production of alkylether carboxylic acid.

A Novel Thin Film Resistive Humidity Sensor Based on SolubleConjugated Polymer:(propionic acid)-co-(propargyl alcohol)

A novel soluble conjugated copolymer (propionic acid)-co-(propargyl alcohol) (PA-co-OHP) has been synthesized for the first time using a new palladium acetylide catalyst Pd(PPh3)(2)(C=CC(CH3)(2)OH)(2)(PPB). Thin film resistive humidity sensor based oil the copolymer doped with HClO4 was prepared. The impedance of the sensor changed from 10(3)similar to 10(7) Omega in 95%similar to 30%RH, and the response of that is very quick (<6 sec.). Preliminary results show the copolymer is a promising humidity sensitive material.

Preparation of Macroporous Poly (vinyl alcohol-co-triallyl isocyanurate) Beads Bearing Aminocarboxylic Acid as Functional Groups by Suspension Polymerization

Macroporous poly (vinyl acetate-co-triallyl isocyanurate) beads were prepared with suspension polymerization method. The copolymer beads were then transformed into poly (vinyl alcohol-co-triallyl isocyanurate) by ester exchange reaction. Aminocarboxylic acids were immobilized on the copolymer beads by the esterification of hydroxyl groups with diethyl-lenetriaminepentaacetic bisanhydride. The weak acid exchange capacities, specific surface areas and mean pore diameters of the resultant resin beads were measured.

Effect of topiramate on partial excitatory amino acids in hippocampal dentate gyrus of rats after alcohol withdrawal

BACKGROUND： Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE： To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN ： A randomized control animal experiment SETTING ： Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS： Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS： The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups： control group （n=10）, alcohol group （n=10） and topiramate-treated group （n=10）. Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol （10 mL/kg）, once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy （HPLC） respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES ： ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS： Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group （10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01）. In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol （6.06±0.82, 3.50±0.92, P 〈 0.05）, and the withdrawal scores at 48 and 72 hours were close to those in the control group （4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05）.② Changes of the contents of glutamic acid in hippocampal dentate gyrus： In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [（143.32±11.42）%, （99.12±0.69）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（78.50±16.40）%, （99.12±0.69）%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.30±0.37）%, （118.91±10.40）%, （99.55±12.81）%, （99.08±11.42）%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus： In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [（126.60±8.67）%, （129.17±10.40）%, （99.25±0.87）%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [（89.87±9.93）%, （99.25±0.87）%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [（100.27±0.32）%, （120.81 ±12.63）%, （98.91±7.83）%, （85.92±8.07）%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group （P 〈 0.05）, and those at 30 and 72 hours were close （P 〉 0.05）. CONCLUSION： ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.

Aminooxyacetic acid improves learning and memory in a rat model of chronic alcoholism

Chronic alcoholism seriously damages the central nervous system and leads to impaired learning and memory.Cell damage in chronic alcoholism is strongly associated with elevated levels of hydrogen sulfide（H2S） and calcium ion overload.Aminooxyacetic acid is a cystathionine-β-synthase activity inhibitor that can reduce H2S formation in the brain.This study sought to observe the effect of aminooxyacetic acid on learning and memory in a chronic alcoholism rat model.Rats were randomly divided into three groups.Rats in the control group were given pure water for 28 days.Rats in the model group were given 6% alcohol for 28 days to establish an alcoholism rat model.Rats in the aminooxyacetic acid remedy group were also given 6% alcohol for 28 days and were also intraperitoneally injected daily with aminooxyacetic acid（5 mg/kg） from day 15 to day 28.Learning and memory was tested using the Morris water maze test.The ultrastructure of mitochondria in the hippocampus was observed by electron microscopy.H2S levels in the hippocampus were measured indirectly by spectrophotometry,and ATPase activity was measured using a commercial kit.The expression of myelin basic protein was determined by immunohistochemistry and western blotting.Compared with the control group,latency and swimming distance were prolonged in the navigation test on days 2,3,and 4 in the model group.In the spatial probe test on day 5,the number of platform crosses was reduced in the model group.Cristae cracks,swelling or deformation of mitochondria appeared in the hippocampus,the hippocampal H2S level was increased,the mitochondrial ATPase activity was decreased,and the expression of myelin basic protein in the hippocampus was down-regulated in the model group compared with the control group.All the above indexes were ameliorated in the aminooxyacetic acid remedy group compared with the model group.These findings indicate that aminooxyacetic acid can improve learning and memory in a chronic alcoholism rat model,which may be associated with reduction of hippocampal H2S level and mitochondrial ATPase activity,and up-regulation of myelin basic protein levels in the hippocampus.

氨基酸代谢在非酒精性脂肪性肝病中的作用机制

非酒精性脂肪性肝病(NAFLD)是全球最普遍的慢性肝病之一,影响全球约1/4的人口,预计到2030年将成为肝移植的主要适应证。NAFLD可导致包括支链氨基酸在内的多种氨基酸水平显著异常,进而促进NAFLD的发生发展。提示除葡萄糖代谢和脂质代谢外,氨基酸代谢也在NAFLD疾病进展中发挥了重要作用。为系统了解氨基酸代谢在NAFLD中的作用及其机制,本文针对氨基酸代谢在NAFLD中的研究进展进行了综述。拟探讨氨基酸代谢在NAFLD疾病进展中发挥的作用及其相关机制,为临床防治提供思路和理论依据。

由苯甲醇合成苯甲酸乙酯综合制备实验的课程思政设计

将苯甲酸合成与苯甲酸乙酯制备两个经典实验改造为综合实验,并以改进合成过程实现绿色、高效转化为案例,引导学生通过查阅文献,综合分析合成过程,指出原合成方法存在的问题和不足,提出改进的建议,在此过程中,引导学生将法律法规、实验规范、学科伦理、绿色理念、环保和可持续发展理念等融入实验的设计和实施全过程,使学生在受到基本操作训练的同时得到素质的全面提升。

急性乙二醇中毒诊治的研究进展

急性乙二醇中毒为常见的中毒原因之一,由于缺乏快速准确的诊断方法以及安全有效的药物使得其在临床诊治过程中非常棘手,并且延迟诊治会直接导致严重的器官功能损伤甚至死亡。充分理解急性乙二醇中毒的体内代谢过程、临床表现、实验室检查的准确性和局限性以及治疗方案的适用性对于快速诊断和改善预后具有重要意义。本文综述乙二醇在体内的代谢、中毒后的临床表现以及国内外最新诊断与治疗方法的研究情况等,为临床早期识别与有效治疗急性乙二醇中毒提供方法与思路。

双重交联网络对聚乙烯醇泡沫性能的影响

以聚乙烯醇为原料,硼酸为交联剂,表面活性剂为致孔剂,通过机械搅拌和冷冻-解冻法制备了预交联软质聚乙烯醇泡沫。通过傅里叶变换红外光谱仪(FT-IR)和扫描电子显微镜(SEM)分析了泡沫的化学结构和微观结构,探究了硼酸含量对泡沫密度、吸水率、孔隙率和泡孔结构的影响;并通过γ射线辐照进行后交联提高聚乙烯醇泡沫的力学性能,研究了不同辐照剂量对聚乙烯醇泡沫压缩强度和拉伸强度的影响。结果表明:通过这种双交联方法制备出的PVA泡沫具有致密的泡孔结构和理想的表观密度,密度为0.096g/cm^(3),孔隙率为92.6%,吸水率可以达到自身的17.45倍。PVA泡沫的最佳辐照交联剂量为20~30kGy,压缩强度最高可达34.9kPa,比未交联的PVA泡沫提高了267.3%;拉伸强度达到150.6kPa,断裂伸长率可达126.95%,比未交联的PVA泡沫分别提高了96.1%和59.7%。