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   9119篇
  免费   611篇
  国内免费   4篇
耳鼻咽喉   51篇
儿科学   279篇
妇产科学   243篇
基础医学   1032篇
口腔科学   420篇
临床医学   994篇
内科学   1706篇
皮肤病学   96篇
神经病学   831篇
特种医学   467篇
外科学   1255篇
综合类   380篇
一般理论   11篇
预防医学   950篇
眼科学   175篇
药学   458篇
中国医学   3篇
肿瘤学   383篇
  2021年   137篇
  2020年   62篇
  2019年   121篇
  2018年   135篇
  2017年   110篇
  2016年   115篇
  2015年   141篇
  2014年   177篇
  2013年   310篇
  2012年   410篇
  2011年   431篇
  2010年   253篇
  2009年   228篇
  2008年   373篇
  2007年   409篇
  2006年   393篇
  2005年   386篇
  2004年   370篇
  2003年   333篇
  2002年   343篇
  2001年   283篇
  2000年   279篇
  1999年   258篇
  1998年   117篇
  1997年   110篇
  1996年   104篇
  1995年   87篇
  1994年   96篇
  1993年   85篇
  1992年   221篇
  1991年   220篇
  1990年   233篇
  1989年   200篇
  1988年   214篇
  1987年   218篇
  1986年   191篇
  1985年   196篇
  1984年   100篇
  1983年   101篇
  1982年   74篇
  1981年   73篇
  1980年   58篇
  1979年   87篇
  1978年   86篇
  1977年   66篇
  1976年   55篇
  1975年   56篇
  1974年   59篇
  1972年   59篇
  1971年   65篇
排序方式: 共有9734条查询结果,搜索用时 359 毫秒
1.
2.
Insomnia     
  相似文献   
3.
Liver hemangioma: US-guided 18-gauge core-needle biopsy   总被引:6,自引:0,他引:6  
Heilo  A; Stenwig  AE 《Radiology》1997,204(3):719
  相似文献   
4.
5.
6.
Forty-five displaced olecranon fractures including 14 accompanying dislocated radial heads and seven radial head fractures were treated over a 13-year period by the tension band wiring technique. The use of supplemental internal fixation when necessary allows excellent results with the use of this technique, even in the presence of severe comminution or radial head dislocation. Primary silicone radial head implants fractured in all three patients in which they were used, necessitating repeat surgery in two patients to date. While loss of motion in terminal extension was a common aftermath of displaced olecranon fracture (59%), it was usually minor and functionally insignificant. True Kirschner-wire migration was not a common problem and can probably be eliminated by proper technique. The presence of gaps in the intraarticular surface of the semilunar notch of the ulna produced no ill effects and was compatible with excellent results. If only those cases with isolated olecranon fractures in this series are considered, there were good and excellent results in 29 of 30 cases (97%). Excision of the olecranon fragment(s) should be reserved for those cases when anatomic restoration cannot be achieved with internal fixation.  相似文献   
7.
If proven effective, vaginal microbicides and diaphragms will likely be part of a larger HIV prevention model that includes condoms and other prevention strategies. It is, therefore, important to understand how introducing new prevention methods may affect overall patterns of sexual risk behavior. Data presented were collected as part of a safety and feasibility study of ACIDFORM gel with a diaphragm among 120 women in South Africa. Interviews were administered at enrollment and months 1, 3, 5, and 6 of the trial. Focus groups were conducted at trial exit. Frequency of sex increased significantly after enrollment. This increase appears to be owing to perceived protection from HIV and greater sexual pleasure afforded by the gel. Male condom use was high overall but increased significantly from enrollment. Data suggest this is because of increased partner involvement, increased negotiating power afforded by study participation, and provision of free condoms perceived to be of high quality.  相似文献   
8.
Reduced bone mineral density (BMD) was sporadically reported in patients with Marfan syndrome. This may or may not place the Marfan patient at increased risk for bone fracture. In comparing the BMDs of our patients with those reported in the literature, it seemed that agreement between values, and hence the degree of osteoporosis or osteopenia reported, was dependent on the instrumentation used. The objective of this study was to statistically assess this impression. Bone mineral density measurements from our previously published study of 30 adults with Marfan syndrome performed on a Lunar DPXL machine were compared with studies published between 1993–2000 measured using either Lunar or Hologic bone densitometry instruments. The differences of our measurements compared with those made on other Lunar machines were not statistically significant, but did differ significantly with published results from Hologic machines (P < 0.001). Before progress can be made in the assessment of BMD and fracture risk in Marfan patients and in the evidence-based orthopedic management of these patients, standardization of instrumental bone density determinations will be required along with considerations of height, obesity, age, and sex.  相似文献   
9.
Hospital surveillance for infection control purposes is a well-accepted method of following nosocomial infections in U.S. hospitals. However, hospital surveillance is being increasingly performed for nosocomial events in noninfectious areas, such as quality assurance and other areas of outcomes research. For the continued development of hospital surveillance in all these areas, dramatic growth in the amount of information collected will occur. To accommodate this growth and to validate new approaches in these areas, large amounts of data collection will be necessary. Collection of these data will be quite difficult without the creation of clinical hospital data bases in which large amounts of information are collected as a routine part of patient care, not as an elaborate addition to patient care. Automated hospital information systems, such as the HELP system, can facilitate the conduct of ongoing hospital surveillance not only in infection control but also in a broad range of areas, such as quality improvement outcomes research and cost-containment areas.  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