丝素蛋白纤维及功能化材料的设计与构筑

随着环境污染、资源枯竭和医疗健康等问题的加剧,研发同时满足特定使用性能、安全性及可再生性的新型材料成为当前的发展趋势.而丝素蛋白材料正是以天然蚕丝为基本原材料,经一定的加工和功能化而形成的具有特殊结构、独特性能和广泛应用的生物质材料,近年来在生物医药、生物电子、智能传感等领域展现出巨大的应用潜力.本专论总结了丝素蛋白纤维及功能化材料的最新成果,结合本课题组相关工作,重点阐述了再生丝素蛋白纤维的仿生制备、生物医用支架的构筑与功能化、智能电子材料的设计以及天然多功能蚕丝及其构筑基元制备的研究进展,以期为高性能丝素蛋白材料的设计与构筑提供指导和借鉴.     

Recent developments in capillary and microchip electroseparations of peptides (2017–mid 2019)

The review presents a comprehensive survey of recent developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) for analysis, micropreparation, and physicochemical and biochemical characterization of peptides since 2017 up to about the middle of 2019. Progress in the study of electromigration properties of peptides and in the methodology of their analysis (sample preseparation, preconcentration and derivatization, adsorption suppression, EOF control, and detection) are described. Advances in CE and CEC methods are demonstrated and their applications in the following areas are presented: qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. In addition, micropreparative separations and determinations of important physicochemical characteristics of peptides by CE and CEC methods are reported.     

Epimerization and racemization of some chiral drugs in the presence of cyclodextrin and liposomes

The effects of alpha-, beta-, gamma- and dimethyl-beta-cyclodextrins (alpha-, beta-, gamma- and DM-beta-CyDs) and liposomes on epimerization or racemization of etoposide, ethiazide and carbenicillin were examined kinetically. alpha- and beta-CyDs accelerated both epimerization and hydrolysis of carbenicillin. They had no effect on epimerization of etoposide, and did not affect racemization and hydrolysis of ethiazide. DM-beta-CyD retarded epimerization of etoposide, hydrolysis of picroetoposide (which is an epimer of etoposide), and racemization and hydrolysis of ethiazide, but had no effect on epimerization and hydrolysis of carbenicillin. gamma-CyD retarded epimerization of etoposide and hydrolysis of picroetoposide. On the other hand, gamma-CyD accelerated epimerization of carbenicillin. It is suggested that the formation of inclusion complexes between CyDs and etoposide, picroetoposide and ethiazide inhibited the attack of bases such as OH- and buffer components, thereby retarding epimerization, racemization and hydrolysis. On the other hand, alpha-, beta- and gamma-CyDs increased the reactivity of carbenicillin through the OH group, accelerating its epimerization and hydrolysis. Liposomes retarded epimerization of etoposide, hydrolysis of picroetoposide and racemization of ethiazide. Liposomes did not affect epimerization and hydrolysis of carbenicillin. These differences in the effect of liposomes on reactivity may be interpreted in terms of the solubility of the drugs.     

Polymer-surfactant and protein-surfactant interactions

The phase behavior and some physicochemical properties of homopolymers (HP) and hydrophobically modified (HMP) polymers, as well as of polyelectrolytes (PE) and proteins (PR), in the presence of aqueous surfactants, or their mixtures, are discussed. Mixing the above components gives rise to the formation of organized phases, whose properties are controlled by polymer and/or surfactant content, temperature, pH, and ionic strength. Depending on the nature, concentration, and net charge of both solutes, molecular solutions, polymer-surfactant complexes, adsorption onto micelles and vesicles, gels, liquid crystalline phases, and precipitates are observed. Such rich polymorphic behavior is the result of a complex balance between electrostatic, excluded volume, van der Waals, and other contributions to overall system stability. It is also modulated by the molecular details and architecture of both the polymer and the surfactant. Different experimental methods allow investigation of the above systems and getting information on the nature of polymer-surfactant interactions (PSI). Surface adsorption and thermodynamic methods, together with investigation of the phase diagrams, give information on the forces controlling PSI and on the existence of different phases. Conductivity, QELS and viscosity allow estimating the size and shape of polymer-surfactant (protein-surfactant) complexes. Optical microscopy, cryo-TEM, AFM, NMR, fluorescence, and relaxation methods give more information on the above systems. Use of the above mixtures in controlling gelation, surface covering, preparing dielectric layers, and drug release is suggested.     

Recent advances in thin-layer chromatography of pesticides

Advances in the applications of thin-layer chromatography (TLC) and high-performance thin-layer chromatography (HPTLC) for the separation, detection, and qualitative and quantitative determination of pesticides, other agrochemicals, and related compounds are reviewed for the period 1998-2000. Analyses are covered for a variety of samples, such as food, biological, and environmental, and for residues of pesticides of various types, including insecticides, herbicides, and fungicides, belonging to different chemical classes. References on formulation analysis, hydrophobicity studies, and the use of TLC and thin-layer radiochromatography (TLRC) for studies of pesticide metabolism, degradation, uptake, and related studies are also included.     

科教融合视域下高分子材料专业综合实验教学探索与实践

基于科学技术的发展、时代的要求,教育改革势在必行,科教融合是发展的新趋势。《高分子材料综合实验》是高分子材料与工程专业的一门必修课,在学生从学校到工作岗位顺利过渡中起着重要的桥梁作用。科教融合在该门课的教学中显得尤为重要,能使学生综合能力、科学素养得到有效提升。以花生壳吸附剂的制备及其应用为例,介绍了科教融合的教学方法、实施步骤及教学成效,涉及理论知识、实践操作、数据处理、现代仪器使用、谱图解析、论文撰写等多门学科知识,实现了跨界知识体系的交叉融合。科教融合不仅提高学生的兴趣性、积极主动性、综合能力、创新能力、分析解决问题能力,还可提高学生的专业认同感、成就感、社会责任感,树立正确的环保意识,成为推进生态文明建设的中坚力量,有助培养成具有良好科学素养的新工科复合型创新人才。     

Mononuclear,polynuclear, and cluster complexes of molybdenum and their reactions as models of biochemical systems and processes

Data on the composition, structure, and properties (electronic and geometric structure, optical properties, thermodynamic functions) of mononuclear, polynuclear, and cluster complexes of bi-, tri-, tetra-, penta-, and hexavalent molybdenum are summarized and correlated. The thermodynamics, kinetics, and mechanisms of the ligand exchange, protonation deprotonation, redox reactions, and formation decomposition of cluster cores of molybdenum complexes in aqueous solutions are characterized.     

Overall connectivities/topological complexities: a new powerful tool for QSPR/QSAR

Earlier attempts to assess the complexity of molecules are analyzed and summarized in a number of definitions of general and topological complexity. A concept which specifies topological complexity as overall connectivity, and generalizes the idea of molecular connectivities of Randic, Kier, and Hall, is presented. Two overall connectivity indices, TC and TC1, are defined as the connectivity (the sum of the vertex degrees) of all connected subgraphs in the molecular graph. The contributions to TC and TC1, which originate from all subgraphs having the same number of edges e, form two sets of eth-order overall connectivities, eTC and eTC1. The total number of subgraphs K is also analyzed as a complexity measure, and the vector of its eth-order components, eK, is examined as well. The TC, TC1, and K indices match very well the increase in molecular complexity with the increase in the number of atoms and, at a constant number of atoms, with the increased degree of branching and cyclicity of the molecular skeleton, as well as with the multiplicity of bonds and the presence of heteroatoms. The potential of the three sets of eth-order complexities for applications to QSPR was tested by the modeling of 10 alkane properties (boiling point, critical temperature, critical pressure, critical volume, molar volume, molecular refraction, heat of formation, heat of vaporization, heat of atomization, and surface tension), in parallel with Kier and Hall's molecular connectivity indices (k)chi. The topological complexity indices were shown to outperform molecular connectivity indices in 44 out of the 50 pairs of models compared, including all models with four and five parameters.     

Determination of carbohydrates and sweeteners in foods and biologically active additives by high-performance liquid chromatography

A method for the determination of large amounts of carbohydrates (glucose, lactose, maltose, mannose, sucrose, and fructose) and sweeteners (xylitol and sorbitol) by reversed-phase liquid chromatography with refractive index detection without derivatization has been developed. The limits of determination for glucose, fructose, and sucrose in liquid samples were 0.1 g/L, and for xylite, lactose, maltose, mannose, and sorbite, 1 g/L. In solid samples the limits of determination for glucose, fructose, and sucrose were 0.1%, and for xylite, lactose, maltose, mannose, and sorbite, 0.6%. The method is applicable to the analysis of samples of wine, juice, honey, cookies, dairy products, and biologically active additives. The developed method for the determination of carbohydrates and sweeteners in foods and biologically active additives was certified in the Mendeleev Institute for Metrology (St. Petersburg).     

Recent developments in CE and CEC of peptides (2009-2011)

The review brings a comprehensive survey of the recent developments of high-performance electroseparation methods in capillary and microchip formats: zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography and electrochromatography. Applications of these techniques to analysis, isolation, purification and physicochemical and biochemical characterization of peptides are described. Advances in the investigation of electromigration properties of peptides, and in the methodology of their analysis, such as sample preparation, adsorption suppression, EOF control and detection, are presented. New developments, in particular, CE and CEC modes are reported and several types of their applications to peptide analysis are described: conventional qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. Some micropreparative peptide separations are shown and capabilities of CE and CEC techniques to provide relevant physicochemical characteristics of peptides are demonstrated.     

Determination of heavy metals and their speciation in waters and bottom sediments of water reservoirs using inductively coupled plasma atomic emission spectrometry and electrothermal atomic absorption spectrometry

The use of inductively coupled plasma atomic emission spectrometry in combination with electrothermal atomic absorption spectrometry and autoclave sample preparation essentially improved performance characteristics of the determination of heavy metals and simplified analytical procedures for determining their speciation. Inductively coupled plasma atomic emission spectrometry can give information about the concentrations of a wide range of elements in water and bottom deposits at a level of MPC and, thus, is useful for revealing sources of pollution of water reservoirs. More sensitive electrothermal atomic absorption spectrometry was used for determining background concentrations of Pb, Cd, Co, Ni, Cu, Cr, Mo, and As and assessing the speciation of Pb, Cd, Co, Cu, and Zn in waters and bottom sediments. Based on the results of analyses of surface, bottom, and void waters; bottom sediments and their step-by-step extracts; and KMC and DEAE cellulose adsorbents containing charge-separated heavy metals, the ecological status of Kuibyshev, Ivan’kovo, and Rybinsk water reservoirs was assessed.     

Stress-induced increase in the amounts of maysin and maysin derivatives in world premium natural compounds from centipedegrass

The red leaves of centipedegrass are known to produce compounds with stronger antibiotic effects than those produced by green leaves. Therefore, the aim of this study was to identify if stress methods (e.g., gamma irradiation, UV-B irradiation, and wounding) could effectively convert green leaves to red leaves, and thereby increase the production of maysin and maysin derivatives that have been known for antibiotic properties. Our results showed differential concentration changes for different compounds using these stress methods. The concentrations of luteolin increased from 0.014% to 0.019%, 0.022%, and 0.028% following gamma irradiation, UV-B irradiation, and wounding, respectively. The concentration of isoorientin increased from 0.898% to 1.938% and 2.538%, while the concentration of mixed rhamnosylisoorientin and orientin increased from 0.303% to 0.474% and 0.690%, following UV-B irradiation and wounding, respectively. Gamma irradiation produced concentrations of isoorientin, rhamnosylisoorientin, and orientin similar to those found in red leaves. The concentrations of derhamnosylmaysin increased from 0.004% to 0.009%, 0.015%, and 0.024% by gamma irradiation, UV-B irradiation, and wounding, respectively. The concentration of maysin increased from 0.515% to 0.714%, 0.583%, and 0.777% by gamma irradiation, UV-B irradiation, and wounding, respectively, while the concentration of luteolin-6-C-boivinopyranoside increased from 0.324% to 0.834%, 0.979%, and 1.493% by gamma irradiation, UV-B irradiation, and wounding, respectively. According to these results, wounding and gamma irradiation are promising methods for increasing the concentrations of maysin and maysin derivatives.     

Nation-离子液体-碳纳米管复合膜修饰电极的制备及用于抗坏血酸、多巴胺及尿酸的同时测定

制备了一种新颖的Nation-离子液体一多壁碳纳米管复合膜修饰电极,并研究了抗坏血酸（AA）、多巴胺（DA）和尿酸（uA）在该修饰电极上的电化学行为．该修饰电极结合了多壁碳纳米管良好的导电性、离子液体优良的催化性能及Nation的高选择性等优点,对AA、DA和UA的氧化具有很好的催化和分离效果,实现了AA、DA和UA的同时测定．在三者共存体系中,AA和DA、DA和UA的氧化峰电位差分别为148和167mV．对AA、DA和UA的同时检测,线性范围分别为5-3200、1～1100和1-300gmol／L,检出限分别为1．66、0．33和0．33gmol／L．该修饰电极选择性好、稳定性高、重现性好,有望用于实际样品中AA、DA和UA的同时检测．     

奎宁类化合物研究进展

本文介绍了奎宁类化合物的发展历史,并分析了奎宁的化学结构。奎宁类化合物不仅可以作为催化剂,有效催化Michael/Mannich反应、Aza-Henry反应、环加成反应和不对称烯烃异构化反应,并且还可作为其他配体,已经成为不对称合成领域中的不可或缺成员。化学家为了寻找更有效的催化剂及配体,以奎宁类生物碱为前体,对其结构进行改造,改造位点主要集中在C-9位羟基、C-6'位甲氧基、奎宁双环的氮原子和环外烯键上,制备了众多催化剂及配体。此外,奎宁类化合物具有多种独特的生物效应,主要表现在抗疟原虫活性和杀虫活性研究方面。以奎宁为杀虫剂先导结构的优化与杀虫构效关系的系统研究将促进新农药创制学科的发展。     

Atmospheric aerosols: composition, transformation, climate and health effects

Aerosols are of central importance for atmospheric chemistry and physics, the biosphere, climate, and public health. The airborne solid and liquid particles in the nanometer to micrometer size range influence the energy balance of the Earth, the hydrological cycle, atmospheric circulation, and the abundance of greenhouse and reactive trace gases. Moreover, they play important roles in the reproduction of biological organisms and can cause or enhance diseases. The primary parameters that determine the environmental and health effects of aerosol particles are their concentration, size, structure, and chemical composition. These parameters, however, are spatially and temporally highly variable. The quantification and identification of biological particles and carbonaceous components of fine particulate matter in the air (organic compounds and black or elemental carbon, respectively) represent demanding analytical challenges. This Review outlines the current state of knowledge, major open questions, and research perspectives on the properties and interactions of atmospheric aerosols and their effects on climate and human health.     

用ICP研究鹿科动物骨质疏松症的微量元素特征

鹿科动物的骨质疏松症是近几年出现的一种疾病，它影响鹿的生长发育和繁殖，病重者死亡。我们采集梅花鹿和白唇鹿的毛，血样，用低温灰化方法和温法消解处理样品，用ＩＣＰ分析了毛，血清中微量元素的含量。病梅花鹿毛样中Ｍｇ，Ａｌ，Ｃａ，Ｔｉ，Ｆｅ，Ｃｕ，Ｚｎ的含量比正常组高，Ｔｉ，Ｃｕ，Ｚｎ的偏差率大于１５％，而Ｓｉ，Ｍｎ，Ｐ，Ｐ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ比正常组低，Ｖ，Ａｇ，Ｂａ，Ｌａ，Ｃｅ，Ｐｂ存在...     

TSDC spectroscopy of relaxational and interfacial phenomena

Applications of thermally stimulated depolarisation current (TSDC) technique to a variety of systems with different dispersion phases such as disperse and porous metal oxides, polymers, liquid crystals, amorphous and crystalline solids, composites, solid solutions, biomacromolecules, cells, tissues, etc. in gaseous or liquid dispersion media are analysed. The effects of dipolar, direct current (dc) and space charge relaxations are linked to the temperature dependent mobility of molecules, their fragments, protons, anions, and electrons and depend on thermal treatment, temperature and field intensity of polarisation, heating rate on depolarisation or cooling rate on polarisation. Features of the relaxation mechanisms are affected not only by the mentioned factors but also by morphological, structural and chemical characteristics of materials. The interfacial phenomena, especially the role of interfacial water, received significant attention on analysis of the TSDC data. Comparison of the data of TSDC and dielectric relaxation spectroscopy (DRS), differential scanning calorimetry (DSC), 1H NMR spectroscopy with layer-by-layer freezing-out of bulk and interfacial water, adsorption/desorption of nitrogen, water and dissolved organics demonstrates high sensitivity and information content of the TSDC technique, allowing a deeper understanding of interfacial phenomena.     

环境样品中双酚类化合物的固相萃取研究进展

双酚类化合物作为一类内分泌干扰物广泛存在于环境介质中,经过多种途径迁移至人体后,可对人体产生内分泌毒性、细胞毒性、基因毒性、生殖毒性、二噁英毒性和神经毒性,已被加拿大政府风险评估识别为进一步优先控制名录。随着环境领域对双酚类化合物的广泛关注,相关研究工作逐渐向水、沉积物、灰尘和生物样品等多介质开拓。但是,由于不同环境样品在基质复杂性和污染物浓度水平等方面存在显著差异,开发提取效率高、净化选择性好、普适性强、操作简单、高通量的提取和净化方法,有助于实现环境介质中双酚类化合物的高灵敏、批量检测。近年来,新型前处理技术发展迅速,尤其是固相萃取技术,在双酚类化合物提取与净化方面取得了长足的发展,不仅在一定程度上克服了传统提取净化方法存在的耗时、耗力和耗溶剂等不足,而且为新型污染物分析提供了更多的技术支持。该文简述了典型双酚类化合物的理化性质、用途用量和环境危害,重点围绕新型固相萃取吸附剂开发和固相萃取模式转变两个方面,总结了固相萃取在双酚类化合物提取净化方法方面取得的进展。商品化固相萃取产品普适性强,在环境监测领域应用范围较广,适用于双酚类化合物的产品种类有限;新型吸附剂研发聚焦吸附容量(如介孔硅材料、碳纳米材料、金属-有机框架材料、环糊精)和选择性(如分子印迹聚合物和混合模式离子交换聚合物)两个方面,种类多样化可满足不同检测需求;越来越多的高灵敏分析仪器不断推向市场,为适应新的发展形势,固相萃取模式正逐渐向微型化、自动化、简易化等方向发展,如QuEChERS、固相微萃取、磁固相萃取等。