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201.
Syntheses of Two Potential Ligands for Tc-99m Labeling as Diagnosis Agents of Alzheimer''''s Disease
Two types of ligands-biphenyl and stilbene derivatives, whichcan be labeled with Tc-99m for the diagnosis of Alzheimer'sdisease (AD) have been synthesized successfully. The key stepsin these two syntheses involved Suzuki reaction and Wittig reac-tion respectively. The new discovered debromination reactionmay be expanded to the compounds with double or triple bondadjacent to the carbon atom bearing the bromine atoms. Thesetypes of syntheses provide a route to a series of biphenyl andstilbene derivatives that will benefit the search of new imagingagents for AD. 相似文献
202.
Solid-phase microextraction (SPME) with a disposable ionic liquid (IL) coating was developed for headspace extraction of benzene, toluene, ethylbenzene, and xylenes (BTEX) in paints. The SPME fiber was coated with IL prior to every extraction, then the analytes were extracted and desorbed on the injection port of gas chromatography, and finally the IL coating on the fiber was washed out with solvents. The coating and washing out of IL from the fiber can be finished in a few minutes. This disposable IL-coated fiber was applied to determine BTEX in water-soluble paints with results in good agreement with that obtained by using commercially available SPME fibers. For all the four studied paints samples, the benzene contents were under the detection limits, but relatively high contents of toluene, ethylbenzene and xylenes (56-271 microg g(-1)) were detected with spiked recoveries in the range of 70-114%. Compared to the widely used commercially available SPME fibers, this proposed disposable IL-coated fiber has much lower cost per determination, comparable reproducibility (RSD < 11%), and no carryover between each determination. Considering that IL possess good extractability for various organic compounds and metals ions, and that task-specific IL can be designed and synthesized for selective extraction of target analytes, this disposable IL coating SPME might has great potential in sample preparation. 相似文献
203.
204.
Yonghong Wen Zhi Qin Weisheng Liu 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(2):285-289
The extraction of Am3+ and Eu3+ from aqueous picric acid solution by N, N-dinaphthyl-N, N-diphenyl-3,6-dioxaoctanediamide (LI) and 1, 1-(3, 6, 9-trioxaundecanedionyl)diphenothiazine (LII) was investigated by a radioactive tracer technique. Extraction distribution ratios of Am3+ and Eu3+ have been measured as a function of pH, picric acid concentration, extractant concentration, diluent and temperature. The extraction of Am3+ is preferred to that of Eu3+ for both LI and LII, and the latter gives larger separation factor than the former. The equilibrium constants and thermodynamic parameters of extraction reactions were also calculated. 相似文献
205.
206.
氢在GaAs和InP表面上的吸附可以用高分辨率电子能量损失谱(HREELS)来探测。Ga—H,As—H,In—H和P—H键的伸缩振动各自对应于不同的能量损失。但是As—H振动极容易和Ga—H振动追加声子损失相混淆,只有从损失峰的相对强度比较上来区别。实验得到吸附的氢与表面原子的成键情况取决于表面的原子结构及电子分布。对于GaAs(111)面,低暴露量时只形成Ga—H键,而高暴露量时还可以形成As—H键。而InP(111)表面由于是经过磷气氛退火处理的,在低暴露量下In—H与P—H键均可形成。InP(Ⅲ)面上只看到P—H损失峰,说明这个表面是完全以P原子结尾的。在(Ⅲ)面上出现小面的情形,则表面Ⅲ族和Ⅴ族原子均可同氢成键。
关键词: 相似文献
207.
208.
氧氟沙星片剂和滴眼液中氧氟沙星对映体的毛细管电泳拆分及定量分析 总被引:1,自引:0,他引:1
采用环糊精及其衍生物为手性选择剂在CE上对氧氟沙星对映体进行了分离,研究了环糊精种类、浓度、分离电压、温度对分离的影响.重点考察了氧氟沙星的定量线性范围、检测限和重现性,在20-200mg/L浓度范围内,迁移时间重现性的相对标准偏差(RSD)控制在1.13%以内,峰面积重现性的RSD控制在4.3%以内,检测限为1mg/L.结果表明用20mmo1/L二甲基-β-环糊精(DM-β-CD)为手性选择剂,背景电解质为50mmo1/L Na2HPO4,pH=3.0,不加有机添加剂情况下可得到较好的分离效果.同时,对氧氟沙星药品实样进行了分析,建主了一种市售氧氟沙星片剂和滴眼液中氧氟沙星对映体简单、快速的毛细管电泳分离、定量分析方法. 相似文献
209.
本文利用含氢有机硅化合物与含双键的氨基酸酯的加成反应,合成了5种新的有机硅氨基酸衍生物。介绍了一种合成N-烷基取代氨基酸酯的新方法。对新化合物进行了元素和光谱分析鉴定。 相似文献
210.
Chen Xia DU Zhi Qiang WANG Qi XIN Yang Jie WU Wen Lian LI Department of Chemistry Zhengzhou University Zhengzhou Changchun institute of optics Fine Mechanics Physics Chinese Academy of Sciences Changchun 《中国化学快报》2005,(5)
In recent years, the interest in developing luminescent lanthanide complexes has been greatly stimulated by their potential use in electroluminescent displays1. Europium complexes appear most attractive in view of the high photoluminescent efficiency and the high monochromatic red light that are widely exploited in full-color displays2. It has been approved that the second ligand plays an important role in europium complexes, the synergistic complexation of the second ligand can not only lead … 相似文献