首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   38篇
  免费   0篇
  国内免费   2篇
化学   29篇
数学   5篇
物理学   6篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2016年   2篇
  2015年   2篇
  2014年   2篇
  2013年   5篇
  2012年   6篇
  2011年   4篇
  2010年   2篇
  2009年   2篇
  2008年   2篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  2002年   1篇
  1997年   1篇
  1994年   1篇
排序方式: 共有40条查询结果,搜索用时 31 毫秒
31.
Nowadays, cancer is still the second leading cause of death all over the world. Therefore, natural products which have anticancer and antitumor properties are come into prominence. Achillea family is known with anticancer and antitumor activity. Yarrow which has over a hundred bioactive compounds is a member of Achillea family. In current study; components of yarrow which was obtained after methanol extraction and purification were radiolabeled with 125I and effects of these radiolabeled components on the cells were examined with using Caco-2, MCF-7, A-549, PC-3 cell lines. As a result of these studies, seven peaks were obtained and the highest radiolabeling yield was calculated for 125I radiolabeled Peak 7 (95.00 ± 7.07, n = 4). To screen the biological properties of these radiolabeled peaks at determined cell lines, our ongoing effort was to evaluate incorporation percentage with time dependent. Furthermore, 125I-Peak 7 had highest incorporation ratio for whole cell lines and its incorporation percentage was increased with time dependent. Results of these in vitro studies were compatible with previous in vivo studies and traditional use of yarrow plants.  相似文献   
32.
Codeine which was extracted from dry capsules of the opium poppy (Papaver somniferum) was purified by HPLC (High Performance Liquid Chromatography) and characterized by NMR (Nuclear Magnetic Resonance) and IR (Infrared) spectroscopy techniques. The purified compound was labeled with 131I and biodistribution studies were performed in rats. Radioiodinated codeine distributed uniformly in the cerebellum, m.pons, striatum and hypothalamus while the other branch of brain and Stomach, urinary bladder, and small intestine uptakes were significantly higher than other tissues.  相似文献   
33.
Famotidine, a gastrointestinal drug was labeled with 99mTc and its radiopharmaceutical potential was observed on male Albino Wistar rats. Labeling yield was over 95%. Average specific activity and n-octanol/water partition coefficient (lipophilicity) were approximately 74 MBq/mg-0.66 GBq/mg and 3.4, respectively. Biodistribution studies were performed on Albino Wistar rats. The activity per gram tissue was calculated and time-activity curves were generated. The majority of the activity was observed in stomach, small intestines and kidneys. Liver and kidneys showed lower uptake compared to other H2-receptor rich tissues. Results show that 99mTc-famotidine is H2receptor specific. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
34.
以γ-氯丙基三氯硅烷为架桥剂修饰天然沙粒表面使沙粒表面引入架桥基团,然后其为支撑体,以丙烯腈为功能单体、偶氮二异丁腈为引发剂、二乙烯苯即为骨架单体又为交联剂,制备了聚丙烯腈接枝于天然沙粒表面的聚丙烯腈/天然沙粒复合材料(简称复合材料)并通过红外光谱和扫描电镜对复合材料进行表征;红外光谱图中均有分别来自沙粒、功能单体和交联剂的硅羟基、腈基和苯环的特征吸收峰,在复合材料切面扫描电镜图中出现具有不同致密度的两相及其紧密结合体,证明得到了二乙烯苯交联聚丙烯腈/天然沙粒复合材料;然后,复合材料为填充物制备了分离富集微柱,将微柱与火焰原子吸收法(FAAS)联用,以FAAS为检测手段,采用动态吸附,观察了复合材料对有毒重金属离子的吸附性,结果表明,其对Pb2+的吸附远远大于对其他重金属离子的吸附,因此,主要研究了复合材料对Pb2+吸附性;在室温下,溶液pH 和上样流速分别为5.4和4 mL·min-1时,复合材料对Pb2+的饱和吸附容量可达到62.9 mg·g-1;以0.5 mol ·L-1盐酸溶液作为解吸剂对吸留在复合材料中的铅离子进行解吸,解吸液流速为6 mL·min-1时解吸率可达96%。  相似文献   
35.
36.
37.
Summary The aim of this study is to synthesize novel 131I labeled estrone derivatives that may have therapeutical potentials on Estrogen Receptor rich tumors. Two radiolabeled estrone derivatives, [131I]2-iodo-3-methoxy-estra-1,3,5-trien-17-one and [131I]4-iodo-3-methoxy-estra-1,3,5-trien-17-one were synthesized. Ether amino estrone derivatives were obtained from estrone in three steps by means of diazonium compounds. Tissue distribution studies exhibited receptor-mediated uptake in target organs in female Albino Wistar rats. Maximum uptakes for 2-iodo[131I]-3-methoxy-estrone are in stomach, pancreas, intestines and uterus. A similar biodistribution profile was obtained for 4-iodo[131I]-3-methoxy-estrone. However 2-iodo-3-methoxy-estra-1,3,5-trien-17-one has higher uptake in stomach, kidneys, pancreas, and intestines than 4-iodo-derivative.  相似文献   
38.
本文讨论了用原子吸收和电感耦合等离子体发射光谱法(ICP-AES)测定经高压釜溶解的营养性埃及植物,如胡芦巴、甘草和莲座丛,并讨论了该法用于被消解植物样品中多元素日常分析的优点。这些样品具有较宽的元素含量范围,准确地测定这些营养性样品的主量和微量元素特别是有毒元素,对埃及人民的健康非常重要。ICP-AES法同时也用于被视为尼罗河净化剂的水生风信子的分析。分析结果表明,该植物能够有效地吸收有毒元素。被研究的植物经高压釜溶解,其溶液经原子吸收和ICP-AES法测定。作者对分析结果进行了对比,并阐明了二者之间的关系。  相似文献   
39.
The aim of the current study was to design a nucleotide-based radiopharmaceutical which could be labeled with 99mTc and to investigate its radiopharmaceutical efficiency and stability. GHA (glucoheptonate) was used as bifunctional chelate. GHA was labeled with 99mTc by SnCl2 reduction method first, and then G (guanine) was conjugated with 99mTc-GHA at 90 °C. In order to determine its radiopharmaceutical stability, thin layer radio chromatography (TLRC) and electrophoresis were employed. In addition, the results were confirmed using high performance liquid radio chromatography (HPLRC). Scintigraphic imaging was performed on rats with mammary tumors, while tissue distribution was determined on Albino Wistar rats. Labeling yield was found to be over 95% and the labeled complex maintained its stability during the study period. The lipophilicity of the 99mTc-GHG was measured and the partition coefficient (logP) of the labeled compound calculated. The results demonstrated that the uptake of 99mTc-GHG (99mTc-glucoheptonate-guanine) reached its maximum at 3 hours p.i. in stomach and intestines. Main way of excretion was renal. Hepatobiliary excretion was also observed. In conclusion, 99mTc-GHG may be useful as a nucleotide-based radiopharmaceutical for in vivo applications.  相似文献   
40.
Diethylstilbestrol (DES) is a well known, nonsteroidal estrogen with high affinity for the estrogen receptor (ER). Today DES is used to treat breast and prostate cancers. A phosphate derivative of DES [Diethylstilbestrol diphosphate (DES-P)] which is specific to tumor cells consisting alkaline phosphatase enzyme was synthesized and labeled with 99mTc using tin chloride as reducing agent. In vivo biological activity of 99mTc labeled diethylstilbestrol phosphate compound (99mTc-DES-P) was examined by biodistribution studies on Wistar Albino rats. Statistical evaluation was performed using SPSS 13 program. The percentage (%) radiolabeling yield of 99mTc-DES-P and quality control studies were done by Thin Layer Radio Chromatography (TLRC). Results showed that, 99mTc-DES-P may be proposed as an imaging agent for ER enriched tumors such as uterus and prostate and their metastases in bones.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号