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   237篇
  免费   12篇
  国内免费   18篇
耳鼻咽喉   2篇
儿科学   12篇
妇产科学   1篇
基础医学   29篇
口腔科学   3篇
临床医学   45篇
内科学   68篇
皮肤病学   1篇
神经病学   6篇
特种医学   34篇
外科学   20篇
综合类   15篇
预防医学   7篇
药学   13篇
肿瘤学   11篇
  2022年   2篇
  2021年   3篇
  2019年   2篇
  2018年   2篇
  2017年   3篇
  2016年   3篇
  2015年   4篇
  2014年   6篇
  2013年   5篇
  2012年   1篇
  2011年   2篇
  2010年   7篇
  2009年   11篇
  2008年   5篇
  2007年   19篇
  2006年   6篇
  2005年   2篇
  2004年   4篇
  2003年   5篇
  2002年   4篇
  2001年   6篇
  2000年   8篇
  1999年   5篇
  1998年   17篇
  1997年   16篇
  1996年   17篇
  1995年   10篇
  1994年   19篇
  1993年   4篇
  1992年   2篇
  1991年   4篇
  1990年   8篇
  1989年   15篇
  1988年   7篇
  1987年   4篇
  1986年   4篇
  1985年   5篇
  1984年   3篇
  1983年   3篇
  1982年   1篇
  1981年   5篇
  1980年   5篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
排序方式: 共有267条查询结果,搜索用时 15 毫秒
131.
132.
To identify predictive parameters for incidence and severity of acute graft-versus-host disease (GVHD), 136 patients, transplanted with histocompatible marrow as therapy for aplastic anemia and hematologic malignancies, were examined using univariate and multivariate analyses. The risk of GVHD increased in patients with acute lymphocytic leukemia (p less than 0.05), in sex-mismatched donor-recipient pairs (p less than 0.01), and in patients older than 23.7 yr (p less than 0.05). No other commonly observed factors appeared to have any relationship to GVHD except the presence of certain alleles. The presence of a Cw4 allele or of the Bw21 specificities B49 and B50 were associated with significantly increased risks of GVHD (p less than 0.05), whereas the presence of Aw19 (or the related specificities A29, Aw30, Aw31 , Aw32, Aw33 ) was associated with a significantly decreased risk (p less than 0.01). Using these factors, a regression equation can be constructed that estimates the risk of a given patient to develop clinically significant acute GVHD.  相似文献   
133.
Kawaguchi  T; Golde  DW; Mednis  A; Bersch  N; Clark  S; Remold  HG 《Blood》1986,67(6):1619-1623
Migration-inhibitory factor (MIF) is a lymphokine that acts to localize mononuclear phagocytes (monocytes and macrophages) and perhaps to activate them. Mo cells are a human T cell leukemia virus II-infected T cell line previously shown to secrete large quantities of MIF upon stimulation with phytohemagglutinin and phorbol myristate acetate. MIF was purified from Mo cell-conditioned medium by gel filtration, phenyl- Sepharose affinity chromatography, isoelectrofocusing, and reverse- phase high-performance liquid chromatography (RP-HPLC). Overall purification was 6,000-fold. The purified MIF fraction was found to display potent colony-stimulating factor (CSF) activity when assayed on human bone marrow cells. The double peak of MIF activity as shown by C 18-RP-HPLC coincided with the double peak of CSF activity. A monoclonal antibody selected for its anti-MIF activity absorbed both the CSF and the MIF activity. These findings indicate that MIF and CSF are either identical molecules or closely related molecules with common structural elements.  相似文献   
134.
135.

Background  

Subtraction of Dynamic Contrast-Enhanced 3D Magnetic Resonance (DCE-MR) volumes can result in images that depict and accurately characterize a variety of liver lesions. However, the diagnostic utility of subtraction images depends on the extent of co-registration between non-enhanced and enhanced volumes. Movement of liver structures during acquisition must be corrected prior to subtraction. Currently available methods are computer intensive. We report a new method for the dynamic subtraction of MR liver images that does not require excessive computer time.  相似文献   
136.
137.
138.
The baboon oviductal epithelium differentiates into a tall columnarepithelium consisting of ciliated and secretory cells duringthe follicular phase of the menstrual cycle in response to risingoestradiol levels. The apical tips of these secretory cellsare filled with membrane-bound secretory granules. During theluteal phase when progesterone levels are elevated, the epitheliumregresses and deciliation occurs. Analysis of secretory proteinsobtained from explant culture media by SDS-PAGE followed byfluorography or Western Blots has revealed that the baboon oviductsynthesizes and secretes a high molecular weight glycoproteinduring the follicular phase of the cycle. Immunocytochemistrydemonstrated that the oviductal glycoprotein is localized tothe secretory granules of epithelial secretory cells, is oviductspecific, and that following secretion the oviductal glycoproteinbinds to the zona pellucida and periviteline space of ovulatedoocytes and embryos within the oviduct. Similar proteins havebeen characterized in other mammalian species. cDNA data showthat the complete coding sequence is 2228 bp for a protein of623 amino acids. A Genbank search showed that baboon oviductalglycoprotein has high homology to other oviductal glycoproteinsequences at both the nucleotide and amino acid levels. Studiesconducted to date probing the biological function of oviductalglycoprotein indicate that this protein plays a role in prefertilizationreproductive events (sperm capacitation; sperm-zona binding;zona penetration). Additional experiments are needed to reveala specific function and mechanism for this molecule.  相似文献   
139.
140.
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