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1.
By mass-spectrometric methods, cholesterol and docosanoic, heneicosanoic, cicosanoic, octadecanoic, cis-octadec-9-enoic, heptadecanoic, hexadecanoic, and pentadecanoic acids have been identified in the odoriferous secretion of the pre-anal glands of the females and males of the common adder and the saw-scaled viper and in those of females of the common mamushi. It has been established that the chemical compositions of the secretions of these glands of the females of the adder, the viper, and the mamushi and of the males of the adder and of the viper are not identical.Institute of Bioorganic Chemistry, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 421–423, July–August, 1986.  相似文献   

2.
翻译后修饰是蛋白质组学研究的前沿和重点,它不仅调节着蛋白质的折叠、状态、活性、定位以及蛋白质间的相互作用,也能帮助科学家更全面地了解生物体的生命过程,为疾病的预测、诊断和治疗提供更加强大的支撑和依据。翻译后修饰产物(例如磷酸化肽和糖肽)丰度很低,且存在着强烈的背景干扰,很难直接用质谱进行分析,因此迫切需要开发高效的富集材料和技术来选择性富集翻译后修饰产物。近年来,智能聚合物基材料通过外部物理、化学或生物刺激可逆地改变其结构和功能,实现对磷酸化肽和糖肽高度可控的吸附和脱附,进而衍生开发出一系列新颖的富集方法,极大地吸引研究者们的兴趣。一方面,智能聚合物基材料的响应变化包括材料疏水性的增加或减少、形状和形貌的改变、表面电荷的重新分布以及亲和配体的暴露或隐藏等特性。这些特性使得目标物和智能聚合物基材料之间的亲和力可以通过简单改变外部条件(如温度、pH值、溶剂极性和生物分子等)实现更可控和更智能的精细调节。另一方面,智能聚合物基材料为集成功能模块提供了便捷的可扩展平台,例如特定的识别组件,显著提高了目标物质的分离选择性。智能聚合物基材料在分离方面展现出巨大的潜力,这为蛋白质翻译后修饰产物的分析和研究带来了希望。围绕上述主题,该文依据Web of Science近20年来近50篇代表性文献,概述了智能聚合物基材料在磷酸化肽和糖肽分离及富集中的发展方向。  相似文献   

3.
在合成气(CO+H2)与复合溶剂(水+有机溶剂)液化系统下研究了气氛、温度、催化剂类型对宝日希勒褐煤转化率、油气水产率和CO转化率等液化特征的影响,从而探讨其液化性能。结果表明,在高含水复合溶剂系统中,合成气气氛、反应温度430-450℃适宜宝日希勒褐煤液化转化,转化率可达到81.15%,油气水产率达到71.53%。该液化系统下,含铁、碱和硫复合型催化剂能有效地提高液化转化率和油气水产率,在430℃催化液化下褐煤转化率达92.27%,油气水产率达79.39%。该催化剂有效促进了煤中大分子的裂解和系统中水煤气变换反应进程,沥青质减少,油含量增多。液化油中多环芳烃衍生物在催化液化过程中向单环芳烃衍生物和烷烯烃转化,分子量降低,提高了油品质量。  相似文献   

4.
5.
目的:明确造成前列舒通胶囊不同批次间差异的标志性无机元素,并进行安全性评价。方法:采用ICP-MS测定制剂中Al、As、B、Ba、Ca、Cd、Co、Cr、Cu、Fe、K、Mg、Mn、Mo、Na、Ni、Pb、Sb、Se、Sn、Sr、Ti、Tl、V、Zn和Hg元素含量并进行数据分析。运用主成分及综合评分结合聚类分析手段,确定制剂的特征性元素;进行元素含量和相关性分析,明确不同批次各元素的差异及元素之间的关系;以多元素含量为指标,绘制无机元素谱图。结果:19批样品中均未检测出Se、Mo、Sn、Sb、Tl和Hg,且Pb、Cd、As、Cu、Hg均符合限量标准,无机元素含量谱图趋势一致。主成分分析提取了4个主成分,确定元素B、K、Al、V、Cr、Ca、Ti、Na、Co和Mn可作为特征元素。主成分得分图将19批样品分为两类,聚类分析及综合评分结果与其一致,两类样品中各元素含量存在差异性。相关性分析中,明确了B与K、Al、Cr正相关,K与Cr、Co正相关,V与Cr、Mn正相关,Mn与Co正相关,Ca、Ti、Na两两正相关。结论:通过分析前列舒通胶囊中无机元素含量,确定了特征元素,为前列舒通胶囊质量全面控制研究提供科学依据。  相似文献   

6.
In this study, the aqueous extract Ziziphora clinopodioides was used to biosynthesis of iron nanoparticles. A green, productive, and environmentally method was developed for the valuable study and the effective preparation of the green-synthesis of iron nanoparticles using aqueous extracts from the leaf of Ziziphora clinopodioides as a result of reducing and stabilizing factor. The simplicity of the synthesis procedures and easy work up are the benefits of the present study. The structural and morphological characterization of green‐synthesized FeNPs was performed by Uv–Vis. and FT-IR spectroscopy, XRD, SEM, and EDX techniques. The SEM images have exhibited an equal and uniform spherical morphology in size of 30.04. We also investigated the anti-hemolytic anemia property of FeNPs in an animal model of hemolytic anemia. In vivo assay, induction of hemolytic anemia was done by phenylhydrazine in mice. FeNPs significantly reduced the weight and volume of liver and spleen and the concentration of pro-inflammatory cytokines and increased the body weight, the anti-inflammatory cytokines concentration, and the total platelet, WBC, neutrophil, lymphocyte, eosinophil, monocyte, and basophil counts, and RBC parameters as compared to the untreated mice. About the biochemical parameters, FeNPs significantly increased GPx, CAT, and SOD in serum, liver, and spleen, and also HDL, total protein, and albumin in serum, and decreased GR in serum, liver, and spleen, and also erythropoietin, ferritin, ferrous, creatinine, urea, LDL, triglyceride, cholesterol, GGT, ALT, AST, and ALP in serum as compared to the anemic mice. DPPH test revealed similar antioxidant potentials for FeNPs and Butylated hydroxytoluene. FeNPs had low cell viability dose-dependently against HUVEC cell line. It appears that FeNPs can be administrated as a hematoprotective and anti-hemolytic anemia drug or supplement for the treatment of hemolytic anemia in the clinical trial.  相似文献   

7.
韩广甸  金善炜  吴毓林 《化学进展》2012,24(7):1229-1235
黄鸣龙院士(1898-1979)1919年浙江医药专科学校毕业,1924年德国柏林大学有机药物化学博士;1924-1934年任浙江医专教授、主任,卫生署化学部主任;1934-1940年在欧洲先灵公司等从事研究工作;1940年回国在昆明任中研院化学所研究员,兼任西南联大教授;1945年赴美在哈佛大学,默克公司从事研究工作。1952年绕道欧洲回国,先后在中国人民解放军医学科学院化学系和中国科学院上海有机化学研究所任研究员。1955年当选为中国科学院学部委员(院士)。黄先生一生从事有机化学的教育和研究工作,他在有机化学的“结构与机理”以及“反应和合成”二大方面都作出了在国内外具有深远影响的工作。20世纪40年代黄先生发现了变质山道年4个立体异构体的循环转变,堪称立体化学的经典之作;1948年发表了黄鸣龙还原反应;1952年归国后引领和发展了我国的甾体化学研究,带领了我国甾体药物的生产发展,是我国甾体药物工业的奠基人。黄先生治学严谨,既重视应用研究,又强调基础研究;关注学习新知识、新概念,又更重视实验技术。黄先生教书育人,身体力行,是我国有机化学发展的先驱者和奠基人。  相似文献   

8.
生物光化学   总被引:2,自引:0,他引:2  
蒋丽金 《有机化学》1983,3(2):83-91
生物光化学研究光在动植物体内所引起的生化现象。例如:经过各种不同波长的光辐照后的生命现象,生长规律,某些生理和病理过程,疾病的产生和治疗机理,细胞的辐射损伤和自然防御,以及光合色素在生物进化中的作用等。本文就光引起的现象:视觉、生物钟(光周期性)、植物的光合作用、辐射损伤及其修复、牛皮癣的治疗、新生儿黄疸病的治疗机理,以及光合色素——藻胆蛋白等七种现象,做了综述性的介绍。  相似文献   

9.
It has been empirically known that cholesterol largely increases the viscosity of oleic acid. To clarify the mechanism of the effect of cholesterol on the intermolecular and the intramolecular (segmental) movements of oleic acid in the liquid state, we measured density, viscosity, IR, 1H NMR chemical shift, self-diffusion coefficient, and 13C NMR spin-lattice relaxation time for the liquid samples of oleic acid containing a small amount of cholesterol. Furthermore, the above measurements were also carried out for the samples of oleic acid containing a small amount of cholestanol, cholestane, cholesteryl oleate, ethanol, or benzene. Cholesterol, possessing one OH group and one double bond in its molecular structure, largely increased the viscosity and reduced the self-diffusion and the intramolecular movement of oleic acid. Cholestanol, possessing one OH group but not a double bond, and cholesteryl oleate, not possessing an OH group, also reduced the self-diffusion and the intramolecular movement; cholestane, not possessing an OH group, slightly reduced the self-diffusion and the intramolecular movements. In contrast with these sterols, ethanol and benzene reduced the viscosity and increased the self-diffusion and the intramolecular movements. In addition, cholesterol and ethanol, both having one OH group, promoted the upfield shift of the 1H NMR signal of the carboxyl group of oleic acid; IR difference spectra for the cholesterol/oleic acid system quite resemble those for the ethanol/oleic acid system. These results suggest that oleic acid makes a complex with cholesterol as well as with ethanol. On the basis of the formation of the complex, we have revealed the role and the functional mechanism of cholesterol to the intermolecular and the intramolecular movements of oleic acid in the liquid state.  相似文献   

10.
Published data and the results of the authors' investigations on the electrochemical conversion of carbon, sulfur, and nitrogen oxides and freons into valuable organic products are reviewed. Considerable attention is paid to the probable mechanisms of such processes, the role and position of the radical-ions and free radicals in them, and the effect of the structure of the reagents, the electrolysis conditions, and other factors on the composition and yield of the products. The problems of developing this promising process, which lies at the junction between physical chemistry, organic chemistry, and ecology, are explored. From the contents of a plenary report at the International Symposium “NATO Workshop on Free Radicals in Biology and Environment” (Bardolina, Italy, June 21–26, 1996) [1]. L. V. Pisarzhevskii Institute of Physical Chemistry, National Academy of Sciences of Ukraine, Kiev. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 33, No. 5, pp. 268–283, September–October, 1997.  相似文献   

11.
We introduce a facile and versatile approach for the formation of ball-like polymer–inorganic patchy microcapsules with a tunable shell by combining sol–gel chemistry of silica precursor and phase separation between the polymer and the precursor. Firstly, chloroform-in-water emulsion droplets containing poly(methyl methacrylate) (PMMA), silica precursor [tetraethyl orthosilicate (TEOS)] and co-surfactant sodium dioctyl sulfosuccinate (Aerosol OT or AOT) were prepared by shaking the mixture by hand. Due to the added AOT, water molecules diffuse into the chloroform droplets, and the tiny water droplets would coalesce gradually, triggering the formation of double emulsion droplets. Upon further solvent evaporation, the concentration of the polymer and the silica precursor in the oil shell of the double emulsions increases, leading to the phase separation between the polymer and the precursors (and partially formed silica through the hydrolysis and condensation of TEOS). Because of the confined geometry of the oil shell in the double emulsions, polymeric disc-like structures, stabilized by AOT, were dispersed in the silica precursors. Meanwhile, the silica precursor hydrolyzed and condensed when brought in contact with the aqueous solution, ultimately leading to the formation of a mineralized shell around the polymer domains and the hybrid patchy microcapsules. Effect of synthesis conditions, such as the amount of TEOS, AOT, and PMMA used, the pH value, and solvent evaporation rate on interfacial behavior of the solvent/water; and the morphology of the patchy microcapsules were investigated. Patchy microcapsules with tunable patch size and shape can be generated through tailoring the experimental parameters. Our study indicates that the hybrid patchy microcapsules can be formed by taking advantage of the sol–gel chemistry and the phase separation process, and the underlying generality of the synthesis procedure allows for a variety of applications, including drug storage, coatings, delivery, catalysis, and smart building blocks in self-assembling systems.  相似文献   

12.
This paper demonstrates how simply and rapidly fatty acid esters of mono- and polyhydric alcohols can be separated quantitatively in preparative quantities on Lobar® RP-8 packed columns. After the separation of unknown mixtures, the isolated esters are identified from spectroscopic data (IR/NMR) and, after saponification of the ester components (fatty acids and alcohols), from the retention times of gas and high-pressure liquid chromatographic separations. Thus, in particular, sparingly volatile or nonvolatile partial esters of polyhydric alcohols, as well as the long-chained full esters, can be determined qualitatively and quantitatively. The following fatty acid esters of mono- and polyhydric alcohols have been separated: the i-propylesters of the laurinic and myristinic acids, the i-butyl-, i-octyl- and i-octadecyl-esters of the palmitinic and stearic acids, the mono- and di-fatty acid esters of the 1,3-bis-(2-hydroxyethyl)-5,5-dimethylhydantoins, the mono-, di- and tri-esters of the trimethylalpropane and the full esters of the pentaerythrite.  相似文献   

13.
Protonation and subsequent intramolecular hydrogen bonding as methods to control chain structure and tune luminescence in heteroatomic conjugated polymers were reported experimentally [A. P. Monkman et al., J. Am. Chem. Soc. 124, 6049 (2002)]. In this paper, the structure and photophysical properties of the model teraryl compound of phenylene-pyridylene copolymer before and after protonation are theoretically studied with quantum chemistry methods. From the optimized ground states, intramolecular hydrogen bonding to the adjacent oxygen atom in the alkoxy substituent planarizes the backbone of the molecules, and the optimized detailed results of compound 9 before and after protonation, such as the dihedral angles between the central benzene and the two pyridyl rings, the bond lengths, and the bond angles, are consistent with the experimental results. From the results of the calculated excited states, the protonation and subsequent intramolecular hydrogen bonding result in the redshifts of the absorption, the increase of the ionization energy, the increase of the electron affinity, the decrease of the energy difference of the highest occupied molecular orbital and lowest unoccupied molecular orbital, the decrease of the binding gap, and the delocalization of the electron-hole coherence. The photophysical properties of compound 9 before and after protonation are further studied with a three-dimensional real-space analysis method of transition and charge difference densities (study transition dipole moment and charge transfer in the absorption and fluorescence processes) and two-dimensional real-space analysis method of transition density matrices (study the electron-hole coherence and the excitation delocalization). The calculated results show theoretically an insight understanding on the influence of the protonation and subsequent intramolecular hydrogen bonding to chain structure and photophysical properties.  相似文献   

14.
常见茶叶中14种元素含量分析及重金属风险评价   总被引:1,自引:0,他引:1  
采集传统名茶地标产品样品各3种为实验样品,通过ICP-OES和ICP-MS对样品进行K、Ca、Mg、Mn、B、Cu、Fe、Ni、Zn、Cr、Co、Cd、As、Pb等14种元素的含量测定。利用单因素方差分析、主成分分析、污染评价等方法,对茶叶无机元素含量进行分析和污染评价,并对污染来源进行了研究。结果表明,不同产地茶叶样品中的K、Ca、Mg、Mn、Fe等元素含量差异较大;食品及茶叶安全限量元素Cd、Cr、Pb、As等实测值均未超过国家标准限值;部分元素之间具有正相关性,如Cu与Cd, Cu与Ni, As与Ni两两之间关联性较强;从主成分分析看出Cu、Cd、As和Ni为PC1代表因子,K和Fe分别为PC2和PC3的代表因子,PC1主要代表了金属冶炼、工业排放和垃圾焚烧等方面的贡献,PC2和PC3分别代表了肥料施放和茶叶加工等方面的贡献。  相似文献   

15.
合成了一种吸收波长为 6 80nm的菁染料 有机硼盐复合物光引发剂CDBC ,以 6 80nm激光二极管发射的激光作为光源 ,研究了由CDBC、EA6 12、POTMPTA组成的红光光敏树脂在快速成型工艺中的应用 ,考察了影响树脂几个主要性能即粘度、光固化速度、体积收缩率的因素 .结果表明 ,EA6 12含量高 ,POTMPTA含量低 ,树脂粘度大 ,体积收缩率小 ;相反 ,EA6 12含量低 ,POTMPTA含量高 ,则树脂粘度低 ,体积收缩率大 ;光引发剂CDBC含量 5 %以内时对树脂粘度和体积收缩率没有影响 ,CDBC含量增加 ,树脂的表固速度加快 ,但当CDBC含量大于 3%时 ,表固速度基本不变 .预聚物EA6 12质量分数 70 % ,单体POTMPTA质量分数 2 7% ,光引发剂CDBC质量分数 3%时 ,树脂粘度为 4 2 0mPa·s ,表固时间为 1 0s ,固化体积收缩率为 4 0 % ,具有较好的综合性能 .  相似文献   

16.
简要介绍了转基因产品的发展历程、优缺点以及对转基因产品进行检测分析的迫切性,着重综述了近期基于DNA、蛋白质、生物传感器以及联用技术检测转基因产品的分析方法,最后对转基因产品的分析方法进行了展望.  相似文献   

17.
亚胺类共价有机骨架(I-COFs)是有机单体根据席夫碱(Schiff-base)反应原理缩合形成的一类新型多孔晶体有机材料.I-COFs具有骨架密度低、比表面积大、孔隙率高、单体种类丰富、孔径尺寸可控、结构可功能化、合成方法多样和物化稳定性好等优点.近年来,I-COFs已成为材料科学领域的研究前沿,并广泛用于气体吸附、...  相似文献   

18.
The laws of the fragmentation of the metastable molecular and key fragmentary ions of mono- and dienic alcohols, acetates, aldehydes, hydrocarbons, and epoxy compounds forming components of the pheromones of the turnip, tomato, and bollworm moths and other pests of agricultural crops are discussed, and the use of the laws found in the identification of compounds of this class has been demonstrated.  相似文献   

19.
Ethene-, cyclopropane-, 3-butene-, and cyclopropanemethanetellurol have been synthesized by reaction of tributyltin hydride with the corresponding ditellurides and characterized by 1H, 13C, and 125Te NMR spectroscopy and high-resolution mass spectrometry. The tellurols of this series, with a gradually increasing distance between the tellurium atom and the unsaturated group, have been studied by photoelectron spectroscopy and quantum chemical calculations. Two stable conformations of ethenetellurol and cyclopropanetellurol, five of allyltellurol, and four of cyclopropanemethanetellurol were found. In the photoelectron spectrum of vinyltellurol, the huge split between the first two bands indicates a direct interaction between the tellurium lone electron pair and the double bond. In the allyl derivative, a hyperconjugation effect was found for the most stable conformers. In contrast to the vinyl compounds, no direct interaction between the lone electron pair of X (X = O, S, Se, and Te) and the three-membered ring could be observed in the cyclopropyl derivatives. A hyperconjugation-like effect, which is independent of the relative orientation of the X-H group, is found to increase from S to Te. Thus, the type and extent of the interaction between the TeH group and an unsaturated or cyclopropyl moiety are clarified while the first comparison of interactions between the nonradioactive unsaturated chalcogen derivatives is performed.  相似文献   

20.
The effects of solvents and their properties on electro-spinnability of the as-prepared polystyrene (PS) solutions and the morphological appearance of the as-spun PS fibers were investigated qualitatively by means of a scanning electron microscope (SEM). The eighteen solvents used were benzene, t-butylacetate, carbontetrachloride, chlorobenzene, chloroform, cyclohexane, decahydronaphthalene (decalin), 1,2-dichloroethane, dimethylformamide (DMF), 1,4-dioxane, ethylacetate, ethylbenzene, hexane, methylethylketone (MEK), nitrobenzene, tetrahydrofuran (THF), 1,2,3,4-tetrahydronaphthalene (tetralin), and toluene. The PS solutions in 1,2-dichloroethane, DMF, ethylacetate, MEK, and THF could produce fibers with high enough productivity, while the PS solutions in benzene, cyclohexane, decalin, ethylbenzene, nitrobenzene, and tetralin were not spinnable. Qualitative observation of the results obtained suggested that the important factors determining the electro-spinnability of the as-prepared PS solutions are high enough values of both the dipole moment of the solvent and the conductivity of both the solvent and the resulting solutions, high enough boiling point of the solvent, not-so-high values of both the viscosity and the surface tension of the resulting solutions.  相似文献   

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