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   77篇
  免费   2篇
  2019年   1篇
  2018年   1篇
  2016年   1篇
  2015年   4篇
  2014年   2篇
  2013年   11篇
  2012年   3篇
  2011年   4篇
  2010年   5篇
  2009年   4篇
  2008年   6篇
  2007年   5篇
  2006年   5篇
  2005年   4篇
  2003年   1篇
  2002年   3篇
  2001年   3篇
  2000年   1篇
  1999年   2篇
  1998年   2篇
  1997年   1篇
  1990年   1篇
  1987年   1篇
  1985年   1篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
排序方式: 共有79条查询结果,搜索用时 15 毫秒
1.
The synthesis of esters of norethisterone (17α-ethynyl-17β-hydroxy-estr-4-en-3-one) with acids containing a benzene ring is described, two methods of esterification being compared in terms of yield and convenience. The activities of these esters as long-acting contraceptive agents have been evaluated.  相似文献   
2.
The synthesis of nine new esters of norethisterone (17 alpha-ethynyl-17 beta-hydroxyestr-4-en-3-one) is described, with the esterifying acids bearing an acetylenic or olefinic function in a chain of eight or nine carbon atoms, for evaluation as long-acting contraceptive agents.  相似文献   
3.
Abstract

Novel series of [ddN]-(CH2)n-[TSAO-T] heterodimers have been prepared and tested for their anti-HIV-1 and HIV-2 activity. The most active compound of this series was the [d4T]-(CH2)3-[TSAO-T] heterodimer (EC50 = 0.018 ± 0.03 μM).  相似文献   
4.
5.
We have investigated the value of a gene therapy approach for neuroblastoma (NB), based on retroviral transduction of the IL-1beta or TNF-alpha cytokine genes into human NB lines. Secretion of the corresponding cytokine, was demonstrated in all lines, although with considerable quantitative variations. Cytokine gene expression significantly reduced the proliferation index (p = 0.0001); this effect was associated with either terminal neuronal (one TNF-alpha line) or fibroblast-like differentiation (two IL-1beta lines), leading to growth arrest after a few weeks. Cell surface levels of CD54 and HLA class II remained unaffected, but HLA class I (p < 0.001) and CD58 expression (p = 0.01) increased on SKNSH after TNF-alpha gene transfer. Mononuclear cells from normal allogeneic donors cocultured with both IL-1beta (p < 0.001) and TNF-alpha lines (p < 0.01), showed a significant increase in the proportion of activated T cells (CD3+DR+); however, their cytotoxicity and proliferation rate remained unchanged. Immunotherapy of neuroblastoma will require identification of transduced lines in which cytokine secretion induces phenotypic changes in such a way as to augment their likely immunomodulatory properties without impeding cell growth. Because of the limited efficacy of IL-1beta or TNF-alpha gene transfer alone, further studies should focus on combination with other immunomodulatory agents, to improve their potential efficacy in neuroblastoma.  相似文献   
6.
Yondelis (Trabectedin, ET-743) is a marine anticancer agent currently in Phase II/III development in patients with advanced pretreated soft tissue sarcoma. In the present study, we generated a panel of low passaged tumor cell lines from samples explanted from chemonaive sarcoma patients with different tumor types. We assessed in vitro sensitivity/resistance to Trabectedin and doxorubicin in a panel of sarcoma cell lines and examined the correlation between molecular alterations in DNA repair genes and sensitivity to Trabectedin. We treated cell lines with Trabectedin and doxorubicin in both 96-h and clonogenic assays. In both assays, well-defined groups of resistant and sensitive cell lines were observed. Resistance to Trabectedin did not correlate with resistance to doxorubicin, indicating that the two drugs may have different mechanisms of resistance. p53 mutations and deletions correlated with extreme sensitivity (IC50 < 1 nM) to Trabectedin (P < 0.01). In a pair of isogenic cell lines differing only in the presence or absence of wild-type p53, the absence of p53 rendered cells threefold more sensitive to Trabectedin.  相似文献   
7.
8.
A rapid, sensitive and specific method was developed and validated using liquid chromatography-tandem mass spectrometry (LC/MS/MS) for determination of gefitinib in human plasma and mouse plasma and tissue. Sample preparation involved a single protein precipitation step by the addition of 0.1 mL of plasma or a 200 mg/mL tissue homogenate diluted 1/10 in human plasma with 0.3 mL acetonitrile. Separation of the compounds of interest, including the internal standard (d8)-gefitinib, was achieved on a Waters X-Terra C18 (50 mm x 2.1 mm i.d., 3.5 microm) analytical column using a mobile phase consisting of acetonitrile-water (70:30, v/v) containing 0.1% formic acid and isocratic flow at 0.15 mL/min for 3 min. The analytes were monitored by tandem mass spectrometry with electrospray positive ionization. Linear calibration curves were generated over the range of 1-1000 ng/mL for the human plasma samples and 5-1000 ng/mL for mouse plasma and tissue samples with values for the coefficient of determination of > 0.99. The values for both within- and between-day precision and accuracy were well within the generally accepted criteria for analytical methods (< 15%). This method was subsequently used to measure concentrations of gefitinib in mice following administration of a single dose of 150 mg/kg intraperitoneally and in cancer patients receiving an oral daily dose of 250 mg.  相似文献   
9.
Comparative analysis of partial tuf sequences was evaluated for the identification and differentiation of lactobacilli. Comparison of the amino acid sequences allowed differentiation between species and also between the subspecies of Lactobacillus delbrueckii. The nucleotide sequence comparison allowed differentiation between other subspecies and between some strains. Lactobacilli from several collections and isolates from dairy samples were clearly identified by comparison of short tuf sequences with those of the type strains. In evaluating the taxonomy of the Lactobacillus casei-related taxa, different tuf amino acid signatures are in favour of a classification into three distinct species. The type strain designation for the L. casei species is discussed.  相似文献   
10.
CRB3 (Crumbs homologue 3), a member of the CRB protein family (homologous to the Drosophila Crumbs), is expressed in different epithelium-derived cell types in mammals, where it seems to be involved in regulating the establishment and stability of tight junctions and in ciliogenesis. This protein has been also detected in the retina, but little is known about its localization and function in this tissue. Our goal here was to perform an in-depth study of the presence of CRB3 protein in the mouse retina and to analyze its expression during photoreceptor ciliogenesis and the establishment of the plexiform retinal layers. Double immunofluorescence experiments for CRB3 and well-known markers for the different retinal cell types were performed to study the localization of the CRB3 protein. According to our results, CRB3 is present from postnatal day 0 (P0) until adulthood in the mouse retina. It is localized in the inner segments (IS) of photoreceptor cells, especially concentrated in the area where the connecting cilium is located, in their synaptic terminals in the outer plexiform layer (OPL), and in sub-populations of amacrine and bipolar cells in the inner plexiform layer (IPL).  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