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61.
LaxBa1—xCoO3系导电陶瓷导电性研究 总被引:1,自引:1,他引:1
对LaxBa1-xCoO导电陶瓷的导电性及其导电机制进行了研究,在x=0.5mol处,导电陶瓷具有金属态导是性,在La0.5Ba0.5CoO3陶瓷中,存在着氧缺位和导电电子,并且此种导电陶瓷具有较高的电子和氧离子混合导电特性。 相似文献
62.
孔壁部分有序化的介孔二氧化硅材料的合成与表征 总被引:4,自引:0,他引:4
采用一种“改进的二次晶化”的方法处理介孔二氧化硅SBA-15. 用X射线衍射(XRD)、 透射电镜(TEM)、 电子衍射(ED)、 红外光谱(FTIR)以及固体核磁共振(NMR)等多种技术对样品进行了表征. 结果表明, 在所得样品的孔壁中, 原子的排列方式与普通介孔二氧化硅材料的孔壁不同, 显示一定程度的有序性. 同时, 高度有序的介孔结构得到很好的保持, 且样品的水热稳定性大幅度提高. 相似文献
63.
64.
An efficient and feasible synthetic approach was developed for the synthesis of an array of new flavane derivafives from the substituted benzaldehyde with the reduction of chalcones and subsequent cyclization as the key steps. The purity and structure of the products were confirmed by the elemental analysis and a combination of its IR, ^1H and ^13C NMR, and mass spectra. These synthetic compounds were tested for xanthine oxidase (XO) inhibitions and antifungal actions against Candida albicans, Cryptococcus neoformans, Aspergillus sp. and Trichophyton rubrum. 7-Hydrazinocarbonylmethoxy-4'-methoxyflavane (9) was found to be the most XO inhibitory with IC50=76.4 μmol/L, and the most potent antifungal compound was 4'-hydrazinocarbonylmethoxyflavane (12) with minimal inhibition concentration MIC=8 μg/mL against Trichophyton rubrum. 相似文献
65.
We optimized the hot water extraction of polysaccharides from the root of Henry wood betony (RHWPs) using a uniform test and explored their anti-tumor activities in vitro and in vivo. The optimal extraction conditions were as follows: 40 min extraction time, liquid/solid ratio 30 mL/g, 100 min soaking time, two extraction cycles, 100% ethanol concentration, and extraction temperature of 80 °C. The molecular weight distribution of RHWPs with MWs was 228,600 g/mol and 5001 g/mol. The IR spectrum further indicated that RHWPs are acidic polysaccharides containing pyranose and furan rings. The main monosaccharides found in RHWPs were mannose, ribose, l-rhamnose monohydrate, glucuronic acid, galacturonic acid, glucose, galactose, xylose, arabinose, and fucose. RHWPs inhibited the proliferation of S180 tumor cells and induced apoptosis in vitro. Oral administration of RHWPs to tumor-bearing mice significantly inhibited the growth of the S180 xenografts, accelerated apoptosis in tumor cells, and expanded the necrotic regions. Furthermore, RHWPs also markedly increased the levels of TNF-α, IFN-γ, and IL-2 in the sera of tumor-bearing mice, and activated immune cells such as lymphocytes, NK cells, and macrophages, thereby inducing tumor cell apoptosis. Taken together, RHWPs are a promising anti-tumor agent that ought to be explored further. 相似文献
66.
This paper presents a new simple and sensitive method for the micro-determination of protein containing SH– and –S–S– groups based on the single sweep polarographic wave of an electroactive derivative. In 0.04molL–1 Na3PO4 and 0.2% ascorbic acid solution, protein is heated in a boiling water bath for 15min, the reaction product giving a sensitive reduction wave at –0.70V (vs. SCE). The wave height is linearly proportional to the concentration of protein. The calibration curves of bovine serum albumin (BSA), human serum albumin (HSA), ovalbumin (OVA) and lysozyme (Lyso) are constructed under the optimal conditions. For BSA and HSA, the linear ranges and detection limits are 0.05–24mgL–1 and 0.02mgL–1, respectively. The method has been applied to the determination of protein in human serum samples with satisfactory results. The mechanism of the polarographic wave was also studied, and the results show that S2– ion is released from the protein molecule during the derivatization reaction, the wave being attributed to the reduction of HgS. 相似文献
67.
Deng Y Wang C Shen X Yang W Jin L Gao H Fu S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(20):6006-6013
Novel functional microspheres with multistimuli-responsive properties have been prepared and characterized. The as-prepared microspheres respond to an external magnetic field, environmental temperature, and ultraviolet radiation. The in vitro drug-loading efficiency and drug-release behavior of these microspheres demonstrated that they could be used as drug carriers for drug controlled release. The results of in vivo distribution investigations of these microspheres showed that they exhibit a high magnetic-targeting effect, which holds promise for applications in various fields such as magnetic drug targeting and tissue labeling, among others. 相似文献
68.
This review aims to provide a summary of the progress in TP small molecule fluorescent probes for enzymes in recent years and displays the main fluorescent mechanisms that have been applied to design probes. 相似文献
69.
Jing XU Lan Hua ZHAO Xin Guo WU Hong Mei WANG Ru Xiu CAI College of Chemistry Molecular Science Wuhan University Wuhan Stuff of Chemistry Yunyang Medical College Shiyan College of Resources Environmental Science Wuhan University Wuhan 《中国化学快报》2006,17(7):949-952
Quantification of free radical formation is critical for evaluation and interpretation of many radical-mediated biological processes1-4. Numerous studies have been devoted to the determination of free radicals, but the most of the reports have been focuse… 相似文献
70.
利用傅立叶变换红外(FT-IR)和拉曼(FT-Raman)光谱研究了高浓度磷脂酰胆碱(PC)与牛血清白蛋白(BSA)的相互作用,及Eu3+对该作用的影响.FT-IR结果显示,PC/BSA混合体系中二者的相互作用主要发生在PC头部极性基团,且这一作用随BSA含量的增加而增强,作用后蛋白质二级结构中α螺旋的比例有所增加. FT-Raman光谱说明PC与BSA的相互作用影响磷脂CH链的排列有序程度. PC/BSA/Eu3+体系的红外光谱显示, Eu3+与PC的磷氧键发生了强相互作用,并使蛋白α螺旋的比例进一步增加. 相似文献