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   399700篇
  免费   11895篇
  国内免费   391篇
耳鼻咽喉   4107篇
儿科学   13714篇
妇产科学   7592篇
基础医学   48920篇
口腔科学   6743篇
临床医学   29958篇
内科学   80894篇
皮肤病学   6829篇
神经病学   36425篇
特种医学   15479篇
外国民族医学   101篇
外科学   56488篇
综合类   3216篇
一般理论   62篇
预防医学   38252篇
眼科学   7185篇
药学   25305篇
中国医学   1319篇
肿瘤学   29397篇
  2023年   1239篇
  2022年   845篇
  2021年   3429篇
  2020年   2037篇
  2019年   3874篇
  2018年   28314篇
  2017年   21303篇
  2016年   23421篇
  2015年   6268篇
  2014年   6362篇
  2013年   9830篇
  2012年   22552篇
  2011年   35889篇
  2010年   25840篇
  2009年   16854篇
  2008年   32222篇
  2007年   35310篇
  2006年   13923篇
  2005年   15397篇
  2004年   15745篇
  2003年   15582篇
  2002年   13125篇
  2001年   6344篇
  2000年   6588篇
  1999年   5658篇
  1998年   1069篇
  1997年   925篇
  1996年   774篇
  1995年   724篇
  1992年   3223篇
  1991年   2944篇
  1990年   2848篇
  1989年   2564篇
  1988年   2413篇
  1987年   2229篇
  1986年   2108篇
  1985年   1907篇
  1984年   1413篇
  1983年   1206篇
  1979年   1205篇
  1978年   853篇
  1977年   798篇
  1975年   805篇
  1974年   1002篇
  1973年   995篇
  1972年   935篇
  1971年   922篇
  1970年   879篇
  1969年   925篇
  1968年   804篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
A 13-year-old girl with multiple genitourinary malformations, incomplete bladder exstrophy, urethral duplication with single bladder, septate vagina, and total urinary incontinence is presented. Prior to admission she had undergone surgery for teratoma and calculi of the bladder and partial fecal incontinence. A continent urinary diversion was done by bladder augmentation using a cecal-colonic segment and by surgical closure of the bladder neck. The distal end of the appendix was brought to the skin as an inconspicuous, easily catheterizable, watertight stoma, our modification of the Mitrofanoff procedure. Excision of the vaginal septum, creation of an introitus, and unification of the split clitoris improved the cosmetic appearance of the external genitalia and improved the outlook for a normal sexual life and pregnancy.  相似文献   
994.
995.
BACKGROUND AND OBJECTIVES: The aim of this study was to compare in a prospective nonrandomized study, the efficacy of 2 methods of administering methotrexate (MTX) in the treatment of ectopic pregnancy (EP): transvaginal injection under sonographic control or intramuscular injection (IM). METHODS: Patients with EP who met specific inclusion criteria for medical treatment were treated with MTX: 63 patients (group 1) were treated by IM and 47 patients (group 2) by transvaginal local injection. In group 1, 50 mg/m2 of MTX was injected intramuscularly; in group 2, transvaginal injection of 1 mg/kg of MTX was injected into the ectopic sac under sonographic control. When an additional dose of MTX was required, it was administrated IM at the dosage of 50 mg/m2 in both groups. RESULTS: The overall success rate, defined by a posttreatment normal hCG level (< 10 mUI/mL) was 71.4% in group 1 versus 91.5% in group 2 (P < 0.01); for patients with hCG levels < 2000 mUI/mL, 83% and 96%, respectively (not significant); for patients with hCG > or = 2000 mUI/mL, 37.5% and 86.4%, respectively (P < 0.01). CONCLUSION: In the medical treatment of EP, the efficacy of MTX is greater when administered by local transvaginal injection than by IM injection. We propose local treatment every time EP can be punctured, especially when hCG levels are > or = 2000 mUI/mL.  相似文献   
996.
997.
998.
999.
1000.
The proteome of most parasite species is currently unknown. Hairworms (Nematomorpha), 300 species distributed around the world, are parasitic in arthropods (mainly terrestrial species) when juveniles, but they are free-living in aquatic environments when adult. Most aspects of their systematics and biology are currently unknown. The aim of this paper was (i) to report a novel and reproducible protocol for the analysis of the proteome of hairworms using two-dimensional gel electrophoresis (2-DGE) and mass spectrometry (matrix laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)) and (ii) to determine the level of proteomic divergence between two sympatric but taxonomically unrelated nematomorph species in the adult stage, Paragordius tricuspidatus Dufour (Nematomorpha, Gordiidae) and Spinochordodes tellinii Camerano (Nematomorpha, Gordiidae). In total, 689 protein spots were observed for P. tricuspidatus, 575 for S. tellinii. Only 36.2% spots were shared between the two species. Quantitative analysis of the proteins which are common to both parasite species reveals substantial differences in the pattern of protein expression. These results suggest a rapid evolutionary divergence between these two nematomorph families. Also, to test the value of our MALDI-TOF protocol, we used Actin-2 (Act-2), a protein highly conserved in the course of evolution. Peptide mass fingerprint (PMF) data obtained for Act-2 of P. tricuspidatus and S. tellinii suggest a very high homology with Act-2 of different worms species belonging to the Bilateria phylum (Annelida and Nematoda) and more specifically to Lumbricus terrestris (Annelida, Lumbricidae) and Caenorhabditis elegans (Nematoda, Rhabditidae). We discuss our results in relationship with current ideas concerning the use of proteomics in systematics.  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