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951.
Nafiseh Mansouriieh Mahmoud Reza Sohrabi Morteza Khosravi 《Arabian Journal of Chemistry》2019,12(8):2524-2532
This study synthesized bimetallic Fe/Ni nanoparticles and used them for catalytic degradation of profenofos, an organophosphorus pesticide. This novel bimetallic catalyst (Fe/Ni) was characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis spectroscopy (EDAX) and X-ray diffraction (XRD). The bimetallic nano-catalyst was prepared at diameters of 20–50 nm and was shown to effectively degrade profenofos. A three-factor central composite design combined with response surface methodology was used to maximize profenofos removal using the bimetallic system. A quadratic model was built to predict degradation efficiency. ANOVA was used to determine the significance of the variables and interactions between them. Good correlation between the experimental and predicted values was confirmed by the high F-value (16.38), very low P-value (<0.0001), non-significant lack of fit, an appropriate coefficient of determination (R2 = 0.936) and adequate precision (14.75). The highest removal rate attained was 94.51%. 相似文献
952.
Wenkun Han Song Zhang Jingyu Qian Jianxu Zhang Xuanhang Wang Zhigang Xie Bin Xu Yanqiu Han Wenjing Tian 《化学:亚洲杂志》2019,14(10):1745-1753
A fluorescent, diselenide‐containing 9,10‐distyrylanthracene (DSA) derivative (SeDSA) with aggregation‐induced emission (AIE) characteristic was successfully synthesized and SeDSA nanoparticles (NPs) were prepared through a nanoprecipitation method. SeDSA could coassemble with an antitumor prodrug, diselenide‐containing paclitaxel (SePTX), which could be obtained by precipitation, to form SeDSA‐SePTX Co‐NPs (Co‐NPs). Molecular dynamics (MD) simulations reveal that the driving forces for the self‐assembly behaviors of SeDSA NPs and SePTX NPs are π–π interactions and hydrophobic interactions, respectively, while the driving forces for Co‐NPs include hydrophobic interactions between SeDSA and SePTX, π–π interactions between SeDSA molecules and hydrophobic interactions between SePTX molecules. Meanwhile, Se‐Se bonds play a crucial role in balancing the intramolecular forces. These diselenide‐containing nanoparticles (SeDSA NPs, SePTX NPs and Co‐NPs) exhibit a high stability under physiological conditions and excellent reduction‐sensitivity in the presence of the redox agent glutathione (GSH) because of the selenium‐sulfur exchange reaction between diselenide and GSH. Both SeDSA NPs and Co‐NPs show strong orange fluorescence emissions on the account of the AIE feature of SeDSA and they were easily internalized by HeLa and HepG2 cells. Distinctively, the Co‐NPs combine the advantage of SeDSA and SePTX for cell imaging and antineoplastic activity, and exhibit selectivity of cytotoxicities between neoplasia cells and normal cells. This study highlights the development of diselenide‐containing AIEgens as a unique approach to prepare uniform and stable fluorescent nanoparticles for the application in cell imaging and tumor treatment. 相似文献
953.
Ahmed El Nemr Eman Serag Azza El-Maghraby Shadia A. Fathy Fatma F. Abdel Hamid 《高分子科学杂志,A辑:纯化学与应用化学》2019,56(8):781-793
The purpose of this paper is studying the effect of incorporation of Multiwall Carbon Nanotubes (MWCNT) into two different nanocomposites in poly vinyl alcohol (PVA)/polyvinylpyrrolidone (PVP), and PVA/Polyethylene glycol (PEG). MWCNT were synthesized by chemical vapor deposition (CVD) method using acetylene and Fe/Co/Al2O3 as carbon precursor and catalyst, respectively. Nitric acid and sulfuric acid were used for purification and functionalization of MWCNT. Afterward, highly pure and functionalized MWCNT (0, 0.02, and 0.05% w/w) were incorporated in PVA/PVP and PVA/PEG to synthesize PVA/PVP/MWCNT and PVA/PEG/MWCNT nanocomposites hydrogel membranes that cross-linked by freezing–thawing. PEG and PVP were selected in these nanocomposites as dispersion matrix for MWCNT as well as for increasing the elasticity of the nanocomposites membranes. The morphology of the hydrogels was characterized by SEM, FTIR, XRD, TGA, and the mechanical properties of the hydrogel membranes were investigated. The swelling behavior in different pH-buffer solutions was studied as well as studying weight loss percentage and swelling kinetic. The drug releasing process of the hydrogel membranes was investigated using salicylic acid as a model drug. It was found that MWCNT are dispersed well into the polymers and crystallinity, mechanical properties and thermal stability of the hydrogels contain MWCNT are better than that without MWCNT. Maximum degree of swelling was observed at pH 7 and swelling degree increases with increasing the ratio of MWCNT in the hydrogels from 0.02 to 0.05%. All hydrogel membranes followed non-Fickian mechanism and drug releasing were controlled by varying the pH and amount of MWCNT. 相似文献
954.
The recent progress of wide bandgap (WBG) donor polymers for non-fullerene polymer solar cells (NF-PSCs) were reviewed in detail, which was classified by D-type and D-A type molecular backbones to discuss the related structure-property correlations and put forward an outlook for future innovations. 相似文献
955.
为了研究和解决大跨越输电塔的优化设计问题,以结构截面、根开和腰部尺寸为设计变量,以结构质量为经济性优化目标,以结构各构件应力比差的平方和为等强度优化目标,提出了经济性等强度优化设计方案,建立了优化目标函数,并采用APDL语言编制了相应的优化程序,利用基于共轭梯度法的一阶优化算法对优化目标函数进行了求解.优化计算结果表明,经济性优化设计方案侧重于节省钢材,等强度优化设计方案则侧重于结构的等可靠性,而经济性等强度优化设计方案既可以满足工程的经济性要求,又可以适当提高结构的整体安全性. 相似文献
956.
磁性固相萃取是一种新型的样品前处理技术,具有萃取时间短、吸附能力强、有机溶剂使用量少、操作简单快捷等优点,已经广泛应用于样品的分离提纯.在简要介绍磁性固相萃取技术发展、材料制备的基础上,着重对国内外磁性固相萃取技术在药毒物分析方面的发展现状以及应用进展进行了综述,以期为法庭科学领域相关物证鉴定提供参考,为严厉打击相关违法犯罪活动提供科学理论与实践依据. 相似文献
957.
Wenhua Chen Xue Yao Zhenghui Huang Fei Mao Longfei Guan Yun Tang Hualiang Jiang Jian Li Jin Huang Lubin Jiang Jin Zhu 《中国化学快报》2019,30(1):250-254
A series of novel 2,4-diaminopyrimidine-modified compounds was designed and synthesized. Compound 14 showed micromolar dual inhibitory effect on both FP-2 and PfDHFR, and potential inhibition to the proliferation of P. falciparum 3D7 strain and chloroquine-resistant P. falciparum Dd2 strain. 相似文献
958.
Claudio N. Cavasotto María Gabriela Aucar Natalia S. Adler 《International journal of quantum chemistry》2019,119(2):e25678
The main contributions of our group during the last 15 years developing and using biomolecular simulation tools in drug lead discovery and design, in close collaboration with experimental researchers, are presented. Special emphasis has been given to methodological improvements in the following areas: (1) target homology modeling incorporating knowledge about known ligands to accurately characterize the binding site; (2) designing alternative strategies to account for protein flexibility in high-throughput docking; (3) development of stochastic- and normal-mode-based methods to de novo design structurally diverse protein conformers; (4) development and validation of quantum mechanical semi-empirical linear-scaling calculations to correctly estimate ligand binding free energy. Several successful cases of computer-aided drug discovery are also presented, especially our recent work on viral targets. 相似文献
959.
960.
用高效毛细管电泳前沿分析法研究了酸性药物那格列奈与人血浆白蛋白的结合常数、结合位点和结合率。使用未涂层的毛细管柱 (4 0cm× 5 0 μmi.d .;有效柱长 32cm) ,磷酸盐缓冲溶液 (pH 7.4 ,离子强度0 .17)为背景溶液 ,在紫外检测波长 2 14nm、运行电压 18kV和重力进样 10 0s的条件下 ,利用那格列奈谱峰的平台高度和游离药物浓度的良好线性关系 (r>0 .999,n =6 ) ,测定了那格列奈的游离药物浓度。固定药物浓度 (2 0 0 μmol L ,2 5 0 μmol L) ,考察不同的蛋白质浓度对结合的影响 ;固定蛋白质浓度 (10 0 μmol L) ,考察不同的药物浓度对结合的影响。实验数据采用非线性拟和程序进行处理 ,得到了那格列奈的蛋白质结合参数。高效毛细管电泳前沿分析法测定的数据重现性良好 (RSD <2 .5 % ,n =3) ,在药代动力学和药效学研究方面具有简便、准确的优点。 相似文献