不同取代基的苯酰肼的感染显影及其机理

本文研究了五种苯酰肼化合物(通式为R-Ph-NHNH-COR')对卤化银乳剂感光性能的影响。利用循环伏安、气-质联仪等方法研究了苯酰肼感染显影的作用机理及其影响因素。实验结果表明,通过苯酰肼的感染显影可获得高感、高反差的效果,影响感染显影程度的大小,除了与取代基R,R’结构有密切关系以外,还与乳剂的种类、胶银比、苯酰肼在卤化银颗粒上的吸附等因素有一定关系。另外也发现苯酰肼衍生物取代基结构不同,其作用机理也不尽相同,从而进一步加深了对感染显影机理的认识。     

水溶液中芘的荧光被核酸碱基猝灭的研究

众所周知,稠环芳烃是一类具有致癌性的物质.虽然对其致癌机理的认识尚未形成一致的看法,但一般都认为同稠环芳烃与DNA,蛋白质等生物活性物质的相互作用有关.因为致癌物后的致癌作用最终都是通过损伤细胞中的DNA而实现的.     

Bioinspired crystallization of CaCO3 coatings on electrospun cellulose acetate fiber scaffolds and corresponding CaCO3 microtube networks

This article describes the mineralization behavior of CaCO(3) crystals on electrospun cellulose acetate (CA) fibers by using poly(acrylic acid) (PAA) as a crystal growth modifier and further templating synthesis of CaCO(3) microtubes. Calcite film coatings composed of nanoneedles can form on the surfaces of CA fibers while maintaining the fibrous and macroporous structures if the concentration of PAA is in a suitable range. In the presence of a suitable concentration of PAA, the acidic PAA molecules will first adsorb onto the surface of CA fibers by the interaction between the OH moieties of CA and the carboxylic groups of PAA, and then the redundant carboxylic groups of PAA can ionically bind Ca(2+) ions on the surfaces of CA fibers, resulting in the local supersaturation of Ca(2+) ions on and near the fiber surface, which can induce the nucleation of CaCO(3) on the CA fibers instead of in bulk solution. Calcite microtube networks on the macroscale can be prepared by the removal of CA fibers after the CA@CaCO(3) composite is treated with acetone. When the CA fiber scaffold is immersed in CaCl(2) solution with an extended incubation time, the first deposited calcite coatings can act as secondary substrate, leading to the formation of smaller calcite mesocrystal fibers. The present work proves that inorganic crystal growth can occur even at an organic interface without the need for commensurability between the lattices of the organic and inorganic counterparts.     

Solubilization of C60 by micellization with a thermoresponsive block copolymer in water: Characterization,singlet oxygen generation,and DNA photocleavage

Water‐soluble diblock copolymer, poly(N‐isopropylacrylamide)‐block‐poly(N‐vinyl‐2‐pyrroridone) (PNIPAM_m‐b‐PNVP_n), was found to associate with fullerene (C₆₀), and thus C₆₀ can be solubilized in water. The 63C₆₀/PNIPAM_m‐b‐PNVP_n micelle formed a core‐shell micelle‐like aggregate comprising a C₆₀/PNVP hydrophobic core and a thermoresponsive PNIPAM shell. The C₆₀‐containing polymer micelle formation and its thermoresponsive behavior were characterized using light scattering and ¹H NMR techniques. The hydrodynamic radius (R_h) of the C₆₀‐bound polymer micelle increased with increasing temperature, which was ascribed to the hydrophobic association between dehydrated PNIPAM shells above lower critical solution temperature (LCST). ¹H NMR data suggest that the motion of the PNIPAM block is restricted above LCST due to the dehydration of the PNIPAM shell in water. The generation of singlet oxygen by photosensitization by the C₆₀‐bound polymer micelle was confirmed from photooxidation of 9,10‐anthracenedipropionic acid. Furthermore, DNA was found to be cleaved by visible light irradiation in the presence of the C₆₀‐bound polymer micelle. Therefore, there may be a hope for a pharmaceutical application of the C₆₀‐bound polymer micelle to cancer photodynamic therapy. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Ti/Ru0.1Ti0.1Sn0.8O2电极电容性能研究

低温热分解法制备Ti/Ru0.1Ti0.1Sn0.8O2.XRD表征该样品结构特性,循环伏安和恒流充放电测定电极性能.结果表明,Ti/Ru0.1Ti0.1Sn0.8O2物相属细小的金红石相,在20 mV/s扫速下该电极比电容达933F/g.1000次充放电循环后,比电容衰减23.6﹪,显示良好的循环稳定性和可逆性.     

EPR Effect of Amphiphilic Copolymer Micelles Observed by Fluorescent Imaging

Enhanced permeation and retention(EPR) targeting effect of rhodamine B labeled PEG-b-P(LA-co-DHP) [PEG:poly(ethylene glycol);LA:L-lactide;DHP:2,2-dihydroxylmethyl-propylene carbonate] micelles(RhB-micelles) was observed in H22 liver cancer bearing mice.The RhB-micelles were prepared by conjugating rhodamine B with the DHP units of amphiphilic block copolymer PEG-b-P(LA-co-DHP) followed by subsequent self-assembling of the conjugate.The parent copolymer PEG-b-P(LA-co-DHP) was synthesized by ring-opening copo...     

γ-氨基丁酰胺的合成研究

γ-氨基丁酰胺在食品,医药等领域有着重要作用,但是现有合成路线繁琐、反应条件苛刻、最终产率较低.本文设计以γ-氨基丁酸为原料,经过酰化、氨解作用合成γ-氨基丁酰胺.同时考察了不同的反应条件对产品收率的影响.工艺成熟,适宜工业化生产.     

化学交联聚乙烯醇改性纤维素碱性阴离子交换复合膜的制备与性能

高稳定性碱性阴离子交换膜的制备已成为碱性固体电解质膜研究领域的一大热点.本文通过聚乙烯醇化学交联改性制备出了季铵化羟乙基乙氧基纤维素碱性阴离子交换膜（PVA/QHECE）.采用傅里叶变换红外（FTIR）光谱、热重（TG）分析、交流（AC）阻抗等方法考察了复合膜的分子结构、热稳定性、耐碱稳定性及离子电导率等性能.详尽考察了交联时间、交联剂含量、聚合物组成对成膜力学强度、含水率以及OH^-电导率的影响.实验结果表明:随着交联时间的增加,膜的溶胀率降低,力学强度随之增强,而离子电导率随膜含水率的降低没有发生明显变化,室温下OH^-的电导率在3.26×10^-4-4.44×10^-4S·cm^-1范围内变化.热重分析结果显示:掺入42.9%的QHECE时,膜的热分解温度达260℃.此外,将PVA/QHECE膜在6 mol·L^-4 KOH浓碱溶液中80℃浸渍处理168 h,膜的电导率从4.90×10^-4S·cm^-1提高到9.68×10^-4S·cm^-1,而膜的外观和力学强度以及含水率未发生明显变化,这一结果表明该膜具有很好的耐碱化学稳定性,有望作为一种新型的碱性燃料电池用离子交换膜.     

Synthesis and Crystal Structure of a Novel Ethyl 5-(4-(2-Phenylacetamido)phenyl)-1H-pyrazole-3-carboxylate as an Acrosin Inhibitor

The title compound (ethyl5-(4-(2-phenylacetamido)phenyl)-1H-pyrazole-3-carboxy- late, C20H19N3O3) was synthesized by the reaction of Claisen condensation, cyclization, reduction and acylation. The structure was characterized by X-ray diffraction, MS, NMR and IR. It belongs to the monoclinic system, space group C2/c with a = 22.723(9), b = 9.324(4), c = 18.890(8) , β = 114.259(6)°, V = 3649(3) 3, Dc = 1.272 Mg·m-3, Z = 8, Mr = 349.38, μ = 0.087 mm-1, F(000) = 1472, the final R = 0.0615 and wR = 0.1643. The biological test shows that the title compound has a moderate acrosin inhibition activity.     

基于配体结构的Grb2-SH2抑制剂的结构优化:更高的活性、更少的电荷、更低的肽性

生长因子受体结合蛋白2(Grb2)在致癌基因Ras活化的信号传导通路中起着关键作用,目前被广泛认为是抗肿瘤药物设计的优秀靶标.对Grb2-SH2抑制剂的研究进展进行了综述,主要针对关键残基磷酸酪氨酸的高电荷性和多肽结构的低生物相容性两个缺陷,基于天然配体与Grb2-SH2相互作用的结构特征,围绕提高活性和简化结构开展的系统构效关系和合理结构优化研究,为进一步开发磷酸酪氨酸介导的Grb2-SH2抑制剂成为新型抗肿瘤药物提供结构和理论基础.