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   4350篇
  免费   307篇
  国内免费   11篇
耳鼻咽喉   50篇
儿科学   179篇
妇产科学   52篇
基础医学   440篇
口腔科学   337篇
临床医学   359篇
内科学   1267篇
皮肤病学   104篇
神经病学   183篇
特种医学   291篇
外科学   569篇
综合类   35篇
一般理论   1篇
预防医学   247篇
眼科学   64篇
药学   236篇
中国医学   13篇
肿瘤学   241篇
  2023年   25篇
  2022年   31篇
  2021年   114篇
  2020年   55篇
  2019年   106篇
  2018年   134篇
  2017年   88篇
  2016年   81篇
  2015年   97篇
  2014年   124篇
  2013年   152篇
  2012年   183篇
  2011年   241篇
  2010年   159篇
  2009年   185篇
  2008年   173篇
  2007年   200篇
  2006年   175篇
  2005年   180篇
  2004年   185篇
  2003年   182篇
  2002年   172篇
  2001年   150篇
  2000年   184篇
  1999年   130篇
  1998年   94篇
  1997年   84篇
  1996年   90篇
  1995年   60篇
  1994年   60篇
  1993年   57篇
  1992年   76篇
  1991年   63篇
  1990年   70篇
  1989年   80篇
  1988年   67篇
  1987年   58篇
  1986年   56篇
  1985年   42篇
  1984年   20篇
  1983年   18篇
  1982年   24篇
  1981年   17篇
  1980年   10篇
  1979年   8篇
  1978年   11篇
  1977年   14篇
  1976年   12篇
  1975年   21篇
  1968年   7篇
排序方式: 共有4668条查询结果,搜索用时 46 毫秒
21.
Autogeneic bone grafts--26 femoral heads, four femoral and two iliac bone grafts--were used in 32 total hip arthroplasties, mainly on patients with complete dislocation of the hip, to reconstruct deficiencies of the acetabular roof by a standardized procedure. At the follow-up examination after 24 to 101 months (median, 52 months), roentgenography demonstrated lateral resorption of the graft in 20 of 32 hips, but resorption involved bone support of the socket in only three of the hips. Analysis of serial roentgenograms showed that resorption was not a function of time. Complete incorporation of the grafts was observed in 27 hips; partial incorporation was shown in three. Roentgenographically, two grafts were not incorporated. None of three grafts of a cortical nature was incorporated. Graft uptake of radioactive tracer was found by 99mTc-diphosphonate emission scintigraphy in 16 of 21 hips, but did not correlate with progressive bone resorption, nonunion, or loss of bone structure. High quality serial roentgenograms showing good bone detail provided the best information about the integrity of the acetabular roof reconstructions.  相似文献   
22.
23.
Gastric mucormycosis involvement is a rare condition that usually occurs in inmunocompromised patients and frequently has a fatal outcome. We report the case of a 73‐year‐old woman admitted to the intensive care unit with severe bleeding after an acute pulmonary disease. Upper endoscopy disclosed wide and deep necrotic ulcers in the body and fundus of the stomach and greenish exudates with the antrum and the duodenum undamaged. Autopsy revealed an invasive mucormycosis and a severe atheromatosis. Several predisposing factors for mucormycosis infection have been reported until now. We postulate that ischemic gastritis could be a predisposing factor for colonization of zygomycete.  相似文献   
24.
Does altered biomechanics cause marrow edema?   总被引:21,自引:0,他引:21  
Schweitzer  ME; White  LM 《Radiology》1996,198(3):851
  相似文献   
25.
26.
Summary Noise levels around educational centres can negatively affect the performance of both teachers and pupils. Two public schools in Valencia, Spain, were selected for study. One of these schools was exposed to excessively high road traffic noise levels while the other was located in a relatively quiet area. The socioeconomic level of those attending the schools was very similar. A set of external and internal noise measurements were carried out, along with two different attention tests among the children. Test results were consistently better (both for tests and for children from different classrooms in each school) in the quiet school. Exposure to high traffic noise levels in the noisy school over the whole school year is a plausible determinant of these results.  相似文献   
27.
28.
The International Conference on Primary Health Care, meeting in Alma-Ata, in the Soviet Union, September 12, 1978, expressed the need for urgent action by all governments, all health and development workers and the world community, to protect and promote the health of all people of the world. The world was caught by the phrase which emerged from this conference, Health For All by the Year 2000 and many have examined the articles of the Alma-Ata declaration and tried to implement them in their corner of the world. This paper describes a community-based smoking-cessation program which was implemented in the province of Nova Scotia, Canada, during the years 1980–1984. Primary to this project was the belief that people have the right and the duty to participate individually and collectively in planning and implementing their health care. This paper describes one community's effort in putting this belief into practice.Carol Smillie, B.N. BE.d. M.S.c. is an Assistant Professor at the School of Nursing, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5, Katherine Coffin, BA, MEd is the Program Officer, Nova Scotia Office, Health Promotion Directorate Health and Welfare Canada, 5251 Duke Street, Halifax, Nova Scotia. Canada B3J 1P3. Kathryn Porter, B.A. (Gen)., is the Information and Education Coordinator, Nova Scotia Division Canadian Cancer Society. Brenda Ryan, B.A., M.B.A. is Program Evaluation Analysist, Nova Scotia Department of Health, 6088 Hollis Street, Halifax. Nova Scotia, Canada. This Project was funded by Health and Welfare Canada, Nova Scotia Department of Health, Nova Scotia Division Canadian Cancer Society, Requests for reprints should be addressed to: Professor Carol Smillie.  相似文献   
29.
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.   相似文献   
30.
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