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1.
范苏娜  陈杰  顾张弘  姚响  张耀鹏 《高分子学报》2021,(1):29-46,I0003,I0001
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.  相似文献   

2.
Recent developments in CE and CEC of peptides   总被引:1,自引:0,他引:1  
Kasicka V 《Electrophoresis》2008,29(1):179-206
  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
Recent advances in thin-layer chromatography of pesticides   总被引:2,自引:0,他引:2  
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.  相似文献   

7.
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...  相似文献   

8.
一般说来,知行观属于功夫修养的范围,因而人们往往将其作为本体思想的一种落实与表现来把握。这当然有一定的道理。但根据儒家传统体与用、本体与功夫之间的互渗互证关系,不仅理学家关于体与本体的思想就表现在其功夫论中,而且从知行功夫的角度也可以逆向甚至更为具体地把握其本体思想。从这一视角出发,宋明知行观的探讨主要表现为程朱的知先行后、王阳明的知行合一以及王夫之的行先知后三种结论;而这三种不同的知行观,既代表着理学发展的三个阶段,同时也体现着理学发展的三个理论制高点,是理学沿着三个不同方向发展所得出的结论。至于其相互的批评、转进与分歧、演变,不仅代表着理学探讨之深入,同时也体现着其边界与底限意识。今天,反思其不同的制高点及其底限之间的互动关系,也是对宋明理学进行研究、总结并推陈出新的应有之义。  相似文献   

9.
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.  相似文献   

10.
11.
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.  相似文献   

12.
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).  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
张立文 《高分子学报》2020,52(4):5-22, 34
自然、社会、人生是由什么支撑的,千变万化的万象是如何归一的,天地万物的终极根源、根据是什么,人如何把握天地万物的资始资生,这就需要进入道体的体用一源的求索。体用思维在中国哲学概念、范畴逻辑结构中已度越一家一派的范围,而敞开胸怀,成为儒释道及诸子用来诠释自己哲学的概念、范畴。程颐提出“体用一源”命题,后人都加以发挥,并进入天人关系的探求,体现为天度越人,又寓于人;交感联通,尽心知天;相分制用,参赞化育;交而相胜,还而相用;天道人性,天人合一。中国哲学的和合生生道体是追寻天地万物存在本原的终极根与底,是对思想的思想终极解释的反思,是追求世界终极价值的形而上者。于是便展开对形而上与形而下的探讨,体现为无形有待,不生有名;有本无体,本末体用;相分不离,和合道体。形而上之道与形而下之器的思维形式,是天地然与所以然、迹与所以迹、共相与殊相、道体与现象、本源与属性、精义入神与礼仪实践的关系。在近代中西文化哲学会通的人文语境下,有中本西末、中体西用、中内西外等主张。  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
奎宁类化合物研究进展   总被引:1,自引:0,他引:1  
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。  相似文献   

19.
用ICP研究鹿科动物骨质疏松症的微量元素特征   总被引:1,自引:0,他引:1  
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...  相似文献   

20.
数字生产力是人类应用数字技术于国民经济活动的生产能力,数字生产力为数字经济提供生产要素和发展动能。数字生产力是先进的科技生产力,是工业社会数字化阶段的标志,是信息科学与数字技术的综合体。数字生产力是生产力要素即劳动者、劳动资料和劳动对象“三位一体”的数字化;数字生产力应用是数字技术与生产力要素融合,实施数字化劳动的过程。数字生产力应用具有专用性和通用性、虚拟性和平台化、共享性和分享性、赋能性与节能性、预测性和精准性,以及“比特”与“原子”共存等特点。数字生产力的劳动应用,表现为数字技术与劳动者、劳动资料和劳动对象有机融合的数字化劳动和新价值创造过程。数字生产力的产业应用,表现为数字农业、数字工业和数字服务业兴起和价值创造。数字生产力的发展是经济增长和国际竞争的关键。  相似文献   

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