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   2881157篇
  免费   222460篇
  国内免费   5438篇
耳鼻咽喉   38876篇
儿科学   95124篇
妇产科学   79994篇
基础医学   409507篇
口腔科学   85697篇
临床医学   259003篇
内科学   557646篇
皮肤病学   63693篇
神经病学   228735篇
特种医学   111987篇
外国民族医学   698篇
外科学   437220篇
综合类   70104篇
现状与发展   6篇
一般理论   1011篇
预防医学   220345篇
眼科学   68279篇
药学   214827篇
  9篇
中国医学   6365篇
肿瘤学   159929篇
  2018年   30284篇
  2017年   23328篇
  2016年   25733篇
  2015年   29485篇
  2014年   40923篇
  2013年   61089篇
  2012年   83803篇
  2011年   88337篇
  2010年   52317篇
  2009年   49192篇
  2008年   83106篇
  2007年   88067篇
  2006年   88959篇
  2005年   85746篇
  2004年   83649篇
  2003年   79865篇
  2002年   77526篇
  2001年   140841篇
  2000年   144894篇
  1999年   121299篇
  1998年   32837篇
  1997年   29244篇
  1996年   29180篇
  1995年   28167篇
  1994年   26221篇
  1993年   24406篇
  1992年   96119篇
  1991年   93360篇
  1990年   90527篇
  1989年   87308篇
  1988年   80447篇
  1987年   78871篇
  1986年   74941篇
  1985年   71935篇
  1984年   53315篇
  1983年   45780篇
  1982年   26369篇
  1981年   23595篇
  1979年   49392篇
  1978年   34075篇
  1977年   28964篇
  1976年   27175篇
  1975年   28778篇
  1974年   35095篇
  1973年   33735篇
  1972年   31166篇
  1971年   29229篇
  1970年   27035篇
  1969年   25320篇
  1968年   23315篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
144.
145.
There is a large and growing population of long-term cancer survivors. Primary care physicians (PCPs) are playing an increasingly greater role in the care of these patients across the continuum of cancer survivorship. In this role, PCPs are faced with the responsibility of managing a range of medical and psychosocial late effects of cancer treatment. In particular, the sexual side effects of treatment which are common and have significant impact on quality of life for the cancer survivor, often go unaddressed. This is an area of clinical care and research that has received increasing attention, highlighted by the presentation of this special issue on Cancer and Sexual Health. The aims of this review are 3-fold. First, we seek to overview common presentations of sexual dysfunction related to major cancer diagnoses in order to give the PCP a sense of the medical issues that the survivor may present with. Barriers to communication about sexual health issues between patient/PCPs in order are also described in order to emphasize the importance of PCPs initiating this important conversation. Next, we provide strategies and resources to help guide the PCP in the management of sexual dysfunction in cancer survivors. Finally, we discuss case examples of survivorship sexual health issues and highlight the role that a PCP can play in each of these case examples.  相似文献   
146.
The aim of the present study was to evaluate the antimicrobial activity of two synbiotic combinations, Lactobacillus fermentum with short-chain fructooligosaccharides (FOS-LF) and Bifidobacterium longum with isomaltooligosaccharides (IMO-BL), against enterohaemorrhagic Escherichia coli O157:H7 and enteropathogenic E. coli O86. Antimicrobial activity was determined (1) by co-culturing the synbiotics and pathogens in batch cultures, and (2) with the three-stage continuous culture system (gut model), inoculated with faecal slurry from an elderly donor. In the co-culture experiments, IMO-BL was significantly inhibitory to both E. coli strains, while FOS-LF was slightly inhibitory or not inhibitory. Factors other than acid production appeared to play a role in the inhibition. In the gut models, both synbiotics effectively inhibited E. coli O157 in the first vessel, but not in vessels 2 and 3. E. coli O86 was not significantly inhibited.  相似文献   
147.
Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets.  相似文献   
148.
149.
150.
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