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   264篇
  免费   14篇
耳鼻咽喉   2篇
儿科学   4篇
妇产科学   3篇
基础医学   39篇
口腔科学   5篇
临床医学   29篇
内科学   55篇
皮肤病学   10篇
神经病学   4篇
特种医学   30篇
外科学   22篇
综合类   8篇
预防医学   14篇
眼科学   3篇
药学   41篇
肿瘤学   9篇
  2022年   3篇
  2021年   3篇
  2020年   6篇
  2018年   4篇
  2017年   3篇
  2016年   7篇
  2015年   5篇
  2014年   3篇
  2013年   5篇
  2012年   8篇
  2011年   3篇
  2010年   9篇
  2009年   10篇
  2008年   5篇
  2007年   17篇
  2006年   7篇
  2005年   10篇
  2004年   8篇
  2003年   7篇
  2002年   6篇
  2001年   4篇
  2000年   7篇
  1998年   6篇
  1997年   5篇
  1996年   7篇
  1994年   4篇
  1993年   4篇
  1992年   4篇
  1991年   3篇
  1990年   4篇
  1989年   5篇
  1988年   10篇
  1987年   4篇
  1986年   4篇
  1985年   5篇
  1984年   5篇
  1983年   5篇
  1982年   5篇
  1980年   3篇
  1978年   5篇
  1977年   2篇
  1976年   8篇
  1975年   4篇
  1974年   2篇
  1973年   5篇
  1972年   6篇
  1971年   3篇
  1970年   3篇
  1969年   4篇
  1967年   7篇
排序方式: 共有278条查询结果,搜索用时 0 毫秒
101.
102.
103.
104.
Derivatives of guanidine, esters, amides, and symmetrical bisquaternary salts in the 3,9-diazabicyclo[3,3,1]nonane series have been synthesized as substances with a potential neurotropic activity. The results of a pharmacological study of the substances synthesized are presented.DeceasedTranslated from Khimiko-Farmatsevticheskii Zhurnal, No. 2, pp. 32–38, February, 1967.  相似文献   
105.
106.
We report on a patient with a clinically diagnosed Philadelphia negative chronic myelogenous leukemia (CML) with a so far unrecorded complex translocation event between the two homologue chromosomes 5. At the GTG-band level the karyotype was normal, apart from an enlarged chromosome 5 and an extremely shortened second chromosome 5. Both derivative chromosomes 5 consisted exclusively of #5 derived material as proven by 24-color FISH. To characterize the complex aberration in more detail the multicolor banding (MCB) technique using a chromosome 5 specific probe set was applied. Using this DNA-based high resolution banding procedure, the karyotype could be described as 46,XX,del(5)(pterright curved arrow q12::q33right curved arrow qter),ins(5)(pterright curved arrow q15::q12right curved arrow q21::q21right curved arrow qter). In consequence, the aberration leads to a partial deletion of the long arm of chromosome 5: del(5)(q21q33), which would not have been identified using conventional banding techniques or 24-color FISH.  相似文献   
107.
The peripheral blood mononuclear cells from 16 patients with B-chronic lymphocytic leukemia (B-CLL, n = 13), B-prolymphocytic leukemia (B-PLL, n = 2) or hairy cell leukemia (n = 1) were incubated in the presence of the phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) and the calcium ionophore A23187. A synergy between these inducers was found with respect to morphological changes and B cell proliferation and differentiation. A23187 used alone did not activate the cells. B-CLL cells treated with the double stimulus acquired a plasmacytoid morphology, showed significantly higher incorporation of 3H-thymidine and 3H-uridine, and produced significantly higher amounts of monoclonal immunoglobulin compared with the same cells exposed to either of the inducers alone. These results indicate that phorbol ester and calcium ionophore act synergistically on B-CLL cells to induce proliferation and differentiation. B-PLL cells responded more vigorously to the signals provided by TPA and A23187. Previous studies showed that TPA and A23187 can mimic the two physiological second messengers diacylglycerol and inositol trisphosphate in the transduction of signals leading to cell activation, proliferation, and differentiation in normal B cells. The present findings suggest that the capacity of B- CLL and B-PLL cells to differentiate in response to signals of the second messenger pathway is intact.  相似文献   
108.
Evaporation of paraffin and ultra-high-molecular-weight polyethylene admixed with alumina powder for the slip casting and sintering process allowed the obtainment of segmented porous alumina ceramics with 50% total porosity, whose deformation behavior we studied. Structurally, these ceramic materials were composed of large and small pores, and a system of discontinuities subdividing the samples into segments. Using digital image correlation (DIC), strain distribution maps were obtained that allowed the observation of strain localization zones, where primary cracks propagated along the interblock discontinuities. Two stages were revealed to be responsible for different mechanisms that provided the sample with damage tolerance under compression loading: the first stage was crack propagation along the block boundaries, which was followed by the second stage of microcracking and fragmentation, consisting of filling of the free spaces with fragments, compaction band generation, and stabilization of the crack. Both stages comprise a cycle that is repeated again and again until the full volume of the sample is occupied by the compaction bands.  相似文献   
109.
High values of electrical conductivity are obtained at the detonation of condensed high explosives with the formula CaHbNcOd. Such values can be explained only in the framework of the contact conductivity hypothesis. In this case, the conductivity is provided by elongated highly-conductive structures which penetrate the whole space of the detonation wave. This work is devoted to the investigation of the detonation soot of high explosives with a significant carbon content in order to discover elongated structures supporting the contact conductivity hypothesis.

Micrographs of transmission electron microscopy of saved detonation products of benzotrifuroxane at different scales.  相似文献   
110.
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