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   1461篇
  免费   117篇
  国内免费   20篇
耳鼻咽喉   4篇
儿科学   104篇
妇产科学   11篇
基础医学   173篇
口腔科学   64篇
临床医学   151篇
内科学   260篇
皮肤病学   61篇
神经病学   96篇
特种医学   251篇
外科学   171篇
综合类   29篇
预防医学   69篇
眼科学   19篇
药学   46篇
  1篇
肿瘤学   88篇
  2022年   5篇
  2021年   17篇
  2020年   16篇
  2019年   16篇
  2018年   26篇
  2017年   11篇
  2016年   19篇
  2015年   37篇
  2014年   36篇
  2013年   48篇
  2012年   40篇
  2011年   48篇
  2010年   69篇
  2009年   66篇
  2008年   40篇
  2007年   47篇
  2006年   37篇
  2005年   45篇
  2004年   30篇
  2003年   38篇
  2002年   33篇
  2001年   36篇
  2000年   23篇
  1999年   33篇
  1998年   87篇
  1997年   82篇
  1996年   62篇
  1995年   52篇
  1994年   39篇
  1993年   47篇
  1992年   20篇
  1991年   34篇
  1990年   27篇
  1989年   49篇
  1988年   42篇
  1987年   33篇
  1986年   25篇
  1985年   26篇
  1984年   13篇
  1983年   13篇
  1982年   17篇
  1981年   18篇
  1980年   15篇
  1979年   5篇
  1978年   14篇
  1977年   13篇
  1976年   16篇
  1975年   12篇
  1973年   3篇
  1972年   3篇
排序方式: 共有1598条查询结果,搜索用时 15 毫秒
81.
目的 探讨整合素在体外培养的椎间盘细胞力学传导中的作用。方法采用猪的椎间盘进行体外细胞的分离和培养,对细胞施加周期性液压负荷,通过对细胞的形态学观察、Western免疫印迹、免疫细胞化学染色和免疫荧光,分别检测整合素α3和肌动蛋白在周期性压力下椎间盘细胞中的表达。结果经加压后,纤维环细胞和髓核细胞均可见体积缩小,由多角形转变为细长形,α3和肌动蛋白在AF和NP细胞中的表达均明显减少。结论压力抑制了整合素α3的产生,整合素α3将力的信号转换到细胞内时,进一步影响到与其关系密切的肌动蛋白。  相似文献   
82.
83.
84.
The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.  相似文献   
85.
Objectives: To audit the knowledge and application of internationally recommended newborn resuscitation (NR) guidelines among delivery room (DR) caregivers of Spanish hospitals.
Methods: A questionnaire-type survey on NR equipment and practices was performed in hospitals of the Spanish National Health System classified according to level of care provided.
Results: 88% of the questionnaires were complimented. Limit of viability was set in 23–24 weeks in 78% of the centres. Availability of board-certified and instructors in NRwas significantly higher in level III versus level I–II centres (94 vs. 70% and 78 vs. 51%, respectively). No differences in equipment or knowledge of guidelines of resuscitation were found between centres. Substantial differences were observed in supplementation and monitorization of oxygen, and positive pressure ventilation during resuscitation and transportation.
Conclusion: Equipment availability and knowledge of guidelines of NR does not differ between hospitals independent of their level of care. However, performance during resuscitation and transportation in level III hospitals is in significantly greater acquaintance with internationally recommended NR guidelines.  相似文献   
86.
87.
Infective endocarditis caused by zoonotic microorganisms is an uncommon clinical entity. A 55-year-old man was diagnosed with endocarditis due to Capnocytophaga canimorsus, a commensal bacterium contained in the saliva of dogs, that involved the aortic and tricuspid valves and was complicated by a para-aortic valve abscess and aorta-to-right atrial fistula. The patient was successfully treated with antibiotic therapy and surgical intervention. C canimorsus endocarditis should be considered in patients with culture-negative endocarditis, particularly in immunosuppressed, asplenic or alcoholic individuals who have recently suffered a dog bite or have had close contact with dogs.  相似文献   
88.
89.
CJ Hobbs  JM Wynne  AJ Thomas 《Archives of disease in childhood》1995,73(5):465-9; discussion 469-71
After the introduction of the colposcope for the examination of children suspected of being sexually abused in Leeds, a study was undertaken to describe the findings in detail. A total of 109 consecutive prepubertal girls, mean age 70.4 months were assessed including colposcopic genital and anal examination, and peer group review of reports and photographs. Fifty nine children had signs consistent with blunt force penetrating trauma (hymenal transection/major notch, scar, or hymenal attenuation). Transections were encountered most commonly at 6 o'clock (directly posterior). In 46 the hymenal orifice was gaping with thigh abduction only and in 47 the hymenal orifice transverse diameter was greater than 4 mm on labial separation. Overall, physical findings were commonly present and in only two cases were no signs recorded. Non-specific and frequent findings included patterns of labial and introital reddening. Supportive hymenal signs including swelling, rounding of edge, thickening, distortion, and loss of symmetry were common. Labial fusion was present in 20. Urethral dilatation with labial separation was noted in 14. Physical findings including normality are consistent with abuse and even minor anogenital signs as well as negative findings should be documented. Colposcopy and photography are valuable tools in peer review, teaching, and case management.  相似文献   
90.
Little objective evidence has been published to support the claim that constipation is an important contributory factor in recurrent urinary tract infection (UTI) in childhood. Using a radiological scoring system, two observers assessed faecal loading from abdominal radiographs of children with proved UTIs. There was a significant increase in the degree of faecal loading in children with UTI when compared with controls (r = 0.237). This difference was mainly accounted for by girls with recurrent (greater than five) UTIs. This study confirms an association between recurrent UTI and faecal loading. Further studies are needed to establish if there is a causal relationship and benefits from treatment.  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