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41.
叶黄素简介   总被引:1,自引:0,他引:1  
孟哲  刘红云 《化学教育》2007,28(3):3-4,24
叶黄素属类胡萝卜素,近年研究发现其具有保护视觉、抗氧化、抗癌等作用。本文从叶黄素的结构、性质、来源、生理功效、研究现状及应用前景等方面进行了介绍。  相似文献   
42.
Lung cancer is the leading cause of cancer deaths worldwide and most cancer patients receiving conventional chemotherapy suffer from severe side effects due to the non-selective effects of chemotherapeutic drugs on normal cells. Targeted nanomaterials can obtain excellent accumulation at the tumor site through their active or passive targeting mechanisms, thereby reducing the toxicity of the drugs in various ways. In this study, hyaluronic acid (HA) which could specifically bind to CD44 on the surface of tumor cells, was used to modify amine-caged platinum nanoclusters (Pt NCs-NH2) to obtain targeting HA-Pt NCs-NH2. Based on the differential expression of CD44 on the surface of three lung cells (non-small cell lung cancer cell H1299, small cell lung cancer cell H446, and embryonic lung fibroblast HFL1), HA-Pt NCs-NH2 can differentially enter the three cells and achieve their targeting of non-small cell lung cancer cell (NSCLC) cells. Pt NCs significantly inhibited the proliferation, migration and invasion of NSCLC cells and induced their apoptosis in comparison of classical cisplatin and carboplatin, showing a bright future in early diagnosis and treatment of NSCLC.  相似文献   
43.
Abivertinib represents a highly selective irreversible epidermal growth factor receptor tyrosine kinase inhibitor. Two major metabolites of abivertinib, M7 and MII-6, were detected in human plasma, which are recommended to be monitored for safety reasons in clinical trial. A high-throughput quantification method utilizing liquid chromatography–tandem mass spectrometry was designed and verified to quantify abivertinib's primary metabolites in human plasma. Solid-phase extraction was used to process the plasma, and then the analytes underwent a gradient elution separation in an Aquity UPLC BEH C18 column (1.7 μm, 2.1 × 50 mm) with mobile phase A (10 mm ammonium acetate containing 0.1% formic acid) and mobile phase B (methanol–acetonitrile, 2:8, v/v, with 0.1% formic acid). Ion transitions of M7 (m/z 490.2 → 405.1) and MII-6 (m/z 476.2 → 391.1) were monitored under multiple reaction monitoring mode and electrospray ionization in positive ion mode. This simultaneous determination method was found to have acceptable precision, accuracy and linearity in the 0.5–500 ng/mL range for M7 and the 0.5–500 ng/mL range for MII-6, accompanied by a mild matrix effect but high recovery. Further stability assessments indicated that both analytes remained stable throughout the entire experimental process from harvesting whole blood to plasma extraction and analysis.  相似文献   
44.
Summary Formylferrocenyl-3-hydroxyl-2-naphthoylhydrazone and its transition metal coordination compounds have been synthesized and characterized by elemental analyses, i.r., 1H-n.m.r., u.v.-vis., t.g.-d.t.a. and molar conductivities. The results show that the ligand coordinates to transition metal ions in the enolic form, accompanied by the release of acetate or nitrate.  相似文献   
45.
级联马赫-曾德尔干涉仪光学梳状滤波的理论研究   总被引:11,自引:5,他引:6  
提出一种级联马赫-曾德尔光纤进一步仪,它是采用多个3dB耦合器串联而成的。模拟与分析表明,当光纤进一步臂长度差ΔL按顺序取一系列定值时,将得到性能良好的梳状出射谱图。其进一步峰的边模抑制比随干涉臂数目的增多而变大。  相似文献   
46.
熊洪允  荣喜民 《数学学报》1998,41(4):763-766
设E是阿基米德Riesz空间,有弱单位元e和极大不相交系{ei:i∈I},其中每一个ei都是投影元素.由ei生成的主带记为B(ei).本文考虑如下论述:(a)存在完全正则Hausdorf空间X,使E是Riesz同构于C(X);(b)对每一个i∈I,存在一个完全正则Hausdorf空间Xi使B(ei)是Riesz同构于C(Xi).我们证明(a)可推出(b).但其逆在一般情况下不成立.当(b)成立时,我们得到一些与(a)等价的论述.  相似文献   
47.
聚马来松香乙二醇酯Cu(Ⅱ)配合物固定化漆树漆酶的研究   总被引:1,自引:0,他引:1  
制备了聚马来松香乙二醇酯(MEEP)Cu2 、Ni2 、Ca2 和Mg2 金属离子配合物,并分别以4种配合物为载体固定化漆树漆酶,初步探讨了反应时间对酶固定化的影响,考察了固定化酶的性质.实验结果表明,在反应温度为25℃条件下,漆树漆酶的最佳固定化时间为16h;MEEPCu2 配合物固定化酶的固定化结果较好,重复使用6次后,酶相对保留活力为55.0%;该固定化酶的最适作用温度为40℃,pH值范围为5.89~9.23,固定化漆树漆酶具有比游离酶更好的热稳定性和更广泛的pH值适用范围.  相似文献   
48.
Pseurotin A was isolated from a culture of marine Bacillus sp. FS8D and showed to be active against the proliferation of four different glioma cells with IC50 values of 0.51–29.3 μM. It has been found that pseurotin A downregulated the expression of tumour glycolytic enzymes pyruvate kinase M2 (PKM2) and lactate dehydrogenase 5 (LDH5) and upregulated the expression of pyruvate dehydrogenase beta (PDHB), adenosine triphosphate synthase beta (ATPB) and cytochrome C (Cyto-C), the important regulators for tricarboxylic acid cycle and oxidative phosphorylation. The data suggested that targeting multiple metabolic enzymes might be one of the antiglioma mechanisms of pseurotin A.  相似文献   
49.
介绍了双格氏试剂、镁杂碳环化合物和含有多官能团的格氏试剂的制备、反应化学及在有机合成中的应用等。  相似文献   
50.
Direct electrochemistry and electrocatalysis of heme proteins, such as hemoglobin (Hb), myoglobin (Mb), and horseradish peroxidase (HRP), incorporated in gluten biopolymer films cast on pyrolytic graphite (PG) electrodes, were studied by voltammetry and amperometry. All the three protein-gluten films exhibited a pair of well-defined, quasi-reversible cyclic voltammetric peaks at about −0.28 V versus saturated calomel electrode (SCE) in pH 5.5 buffers, respectively, characteristic of the heme Fe(III)/Fe(II) redox couples, indicating enhanced electron transfer between the proteins and PG electrodes in a gluten film environment. The protein-gluten hydrogel films showed excellent stability. Positions of Soret absorption band of protein-gluten films suggested that the heme proteins kept their secondary structure similar to their native state in the films in the medium pH range. The heme proteins in gluten films were act as a biologic catalyst to catalyze reduction of oxygen or hydrogen peroxide. The voltammetric or amperometric responses of H2O2 at the protein-gluten film electrodes could be used to determine the concentration of H2O2 in solution.  相似文献   
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