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   1338篇
  免费   107篇
  国内免费   2篇
耳鼻咽喉   5篇
儿科学   80篇
妇产科学   18篇
基础医学   229篇
口腔科学   28篇
临床医学   108篇
内科学   243篇
皮肤病学   16篇
神经病学   88篇
特种医学   96篇
外科学   139篇
综合类   127篇
预防医学   111篇
眼科学   5篇
药学   96篇
肿瘤学   58篇
  2022年   18篇
  2021年   45篇
  2020年   14篇
  2019年   19篇
  2018年   21篇
  2017年   19篇
  2016年   17篇
  2015年   24篇
  2014年   30篇
  2013年   50篇
  2012年   48篇
  2011年   46篇
  2010年   52篇
  2009年   43篇
  2008年   53篇
  2007年   34篇
  2006年   62篇
  2005年   54篇
  2004年   52篇
  2003年   45篇
  2002年   51篇
  2001年   36篇
  2000年   42篇
  1999年   39篇
  1998年   43篇
  1997年   33篇
  1996年   35篇
  1995年   27篇
  1994年   34篇
  1993年   13篇
  1992年   16篇
  1991年   16篇
  1990年   22篇
  1989年   26篇
  1988年   26篇
  1987年   33篇
  1986年   33篇
  1985年   20篇
  1984年   26篇
  1983年   26篇
  1982年   12篇
  1981年   13篇
  1980年   11篇
  1979年   14篇
  1977年   6篇
  1976年   6篇
  1975年   6篇
  1973年   4篇
  1971年   4篇
  1969年   5篇
排序方式: 共有1447条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
5.
In order to evaluate the effects of pentoxifylline on sperm motility and longevity, a controlled in-vitro study was conducted on normozoospermic donor semen samples using the Cellsoft automated system for sperm motility analysis. After incubation and selection, pentoxifylline was found to improve the recovery of spermatozoa and to increase their velocity. In the subgroup of progressively motile spermatozoa, curvilinear velocity was also enhanced. It is concluded that pentoxifylline has an effect on the vigour, but not on the pattern, of sperm motion. Pentoxifylline did not improve the motility characteristics of senescent spermatozoa in normozoospermic sperm samples. Sperm survival, as shown by supra-vital staining, and motility longevity both decreased with time after pentoxifylline treatment.  相似文献   
6.
P-fimbriae vaccines   总被引:3,自引:0,他引:3  
To test for cross-protective capacity of two different P-fimbriae vaccines we vaccinated baboons with fimbriae purified from either Escherichia coli strain ER2 or strain JR1. The vaccinated animals showed elevated antibody titers to P-fimbriae from each of the E. coli strains used, suggesting cross-reactivity as was expected from the results of immunoprecipitation of the fimbriae. Enzyme-linked immunosorbent assay inhibition by heterologous P-fimbriae proved this to be true immunologic cross-reactivity.  相似文献   
7.
A study of 17 patients with autoimmune axonal or demyelinating peripheral neuropathy in combination with M-component is described. The M-component was associated with MGUS (monoclonal gammopathy of undetermined significance) in 12 patients, CLL in one patient, WaldenstrÖm's disease in one patient, and myeloma in three patients. Immunohistological examination with direct and indirect fluorescence showed binding of antibodies to nerve structures of the same class and light chain as seen in the M-component. In five cases of IgM M-component, the demyelinating neuropathy was caused by binding of the IgM M-protein and complement C3b to myelin-associated glycoproteins (MAG). In 12 cases with axonal neuropathy, binding of IgG to the connective tissue of the peri- and endoneurium was found in 50% of cases, IgM in five cases, and IgD in one case. None of the patients had central nervous system (CNS) symptoms. The clinical and therapeutic difficulties are discussed; only two patients with an acute course responded to immunosuppression. A marked co-expression of other autoimmune phenomena is interpreted in the light of cross-reactions between the autoantibody and similar tissue autoantigens.  相似文献   
8.
9.
The ophthalmic findings of 55 dyslexic 12 to 13-year-old Finnish schoolchildren and 50 age, sex, and social class-matched control children were evaluated. On a neuropsychological basis the children could be divided into six subgroups: general deficiency, general language, visuomotor, naming, mixed, and normal. The two groups did not differ significantly from each other in visual acuity, cycloplegic refraction, the amount of phorias and tropias, stereo acuity, fusion, or accommodation. Convergence near point > or = 8 cm was, however, statistically more frequent in the dyslexic group. This finding was also significant in the general deficiency subgroup compared with the other subgroups. The most conspicuous common denominator in those with dyslexia was revealed to be the convergence insufficiency type of exodeviation, occurring in 38% of the general deficiency dyslexic subgroup and in 36% of the visuomotor dyslexic subgroup. This finding suggests a low accommodative convergence/accommodation ratio in these children.  相似文献   
10.
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