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   7973篇
  免费   592篇
  国内免费   32篇
耳鼻咽喉   121篇
儿科学   174篇
妇产科学   134篇
基础医学   1000篇
口腔科学   161篇
临床医学   683篇
内科学   1795篇
皮肤病学   388篇
神经病学   724篇
特种医学   211篇
外科学   1394篇
综合类   31篇
一般理论   2篇
预防医学   629篇
眼科学   174篇
药学   391篇
中国医学   7篇
肿瘤学   578篇
  2023年   49篇
  2022年   76篇
  2021年   226篇
  2020年   115篇
  2019年   202篇
  2018年   245篇
  2017年   166篇
  2016年   169篇
  2015年   219篇
  2014年   293篇
  2013年   382篇
  2012年   544篇
  2011年   513篇
  2010年   284篇
  2009年   287篇
  2008年   429篇
  2007年   457篇
  2006年   427篇
  2005年   418篇
  2004年   369篇
  2003年   344篇
  2002年   315篇
  2001年   167篇
  2000年   175篇
  1999年   151篇
  1998年   77篇
  1997年   69篇
  1996年   60篇
  1995年   57篇
  1994年   67篇
  1993年   62篇
  1992年   109篇
  1991年   128篇
  1990年   102篇
  1989年   81篇
  1988年   89篇
  1987年   80篇
  1986年   75篇
  1985年   67篇
  1984年   56篇
  1983年   48篇
  1982年   32篇
  1981年   36篇
  1979年   27篇
  1978年   25篇
  1977年   26篇
  1976年   19篇
  1975年   23篇
  1973年   19篇
  1972年   22篇
排序方式: 共有8597条查询结果,搜索用时 15 毫秒
1.
2.
3.
Trichotillomania is a form of traction alopecia resulting from repetitive and compulsive hair pulling and plucking. Trichotillomania and patchy alopecia areata may have similar clinical and dermoscopic features in some cases. On trichoscopic examination, the presence of black dots, coiled or hook hair, shafts of varying lengths with fraying or split ends (trichoptilosis), and an absence of exclamation mark hairs and yellow dots are suggestive of trichotillomania.  相似文献   
4.
5.
6.
7.
J Ramon  B Goldwasser  G Raviv  P Jonas  M Many 《Cancer》1991,67(10):2506-2511
From 1974 to 1983, simple and radical nephrectomies were performed at the Chaim Sheba Medical Center (Tel Hashomer, Israel) for renal cell carcinoma. The authors reviewed 109 cases that were followed for a period ranging from 5 to 14 years. Simple nephrectomy was performed in 55 patients, and 54 patients underwent radical nephrectomy. The selection of the surgical procedure was based on the surgeon's preference and not on the basis of clinical stage, age, or sex. The surgical results and survival rates were assessed according to the pathologic stage of the tumors. Among patients with Stage I tumor, radical nephrectomy produced better survival rates at 5 and 10 years (P = 0.03); however, when the non-cancer deaths were excluded, the difference in survival was not statistically significant. For Stage I tumors the survival free of disease at 5 years was better for the radical nephrectomy group, but this difference was not statistically significant. No difference was noticed in the local recurrence rate between the two groups. Nephrectomy in patients with Stage IV disease did not alter survival regardless of the type of operation.  相似文献   
8.
Interactions of cholecystokinin and glucose in rat pancreatic islets   总被引:1,自引:0,他引:1  
The effects of sulfated cholecystokinin (CCK-8S) and glucose on insulin secretion and polyphosphoinositide (PPI) metabolism were studied in isolated rat islets. Both agonists stimulate PPI hydrolysis, inositol phosphate accumulation, 3H efflux from [3H]inositol-prelabeled tissue, and 45Ca efflux from prelabeled cells. However, the effects of CCK-8S on PPI metabolism are considerably greater than those of glucose. Furthermore, the effects of CCK-8S on PPI and Ca2+ metabolism are observed whether islets are incubated in either 2.75 or 7 mM glucose, but CCK-8S only stimulates insulin secretion (a biphasic response) when the higher glucose concentration is present. Addition of 1 microM forskolin to islets incubated in media containing 2.75 mM glucose does not influence basal insulin secretion but sensitizes the islets to the action of CCK-8S. In the presence of forskolin, CCK-8S induces a very marked first phase but no second phase of insulin secretion. We postulate that CCK-8S acts in this tissue via receptor-linked PPI hydrolysis, leading to an inositol trisphosphate-induced Ca2+ efflux. These receptor-mediated effects of CCK-8S are not altered either by the ambient glucose concentration or the cAMP content of the islets, but these two factors determine the responsiveness of the islets (in terms of insulin secretion) to a given CCK-8S signal.  相似文献   
9.
BACKGROUND: The use of suctioned fat grafts for correction of soft tissue defects is a widespread procedure in esthetic and reconstructive surgery. The main disadvantage of this simple and sensible procedure is the unpredictable absorption rate of the fat graft. A lot of research has been performed aiming for enhancement of the take of the fat grafts. OBJECTIVE: Our study was performed to find if there is any favorable donor site for fat harvesting. METHODS: This in vivo experiment using the nude mice model enables the study of the long-term survival of human fat in an animal model. The fat was harvested from three donor areas: the thigh, abdomen, and breast of a 48-year-old woman who came for an elective esthetic procedure. After centrifugation, 1 cc of fat was injected subcutaneously into the scalp of the nude mouse. There were 15 mice in each of the three groups, according to the selected donor sites. The animals were sacrificed 16 weeks after the procedure. The extracted fat was evaluated in terms of weight, volume, and six histologic parameters: integrity, vascularization, cyst formation, fibrosis, necrosis, and inflammation. RESULTS: This study could not find any statistically significant differences between the three investigated donor sites in the evaluated parameters. CONCLUSION: On the basis of this study, there is no favorable area for harvesting fat grafts. The donor site can be chosen according to the preference of the surgeon and the patient.  相似文献   
10.
Background Scleroderma is characterized by abnormal growth of connective tissue, often manifested with hard and tight skin. The viscous properties of the skin are impaired, and the main histologic changes include a thicker dermis, absence of pilosebaceous units, and a decreased space between collagen bundles. Often these patients have wound healing problems.
Objective The objective was to demonstrate a case of scleroderma that had deep phenol perioral peeling and fat injection into the lips. According to our bibliographic search, this is the first report in the English literature of using these modalities in scleroderma patients.
Methods A 64-year-old woman suffering from scleroderma for more than 20 years came for improvement of her perioral appearance. We decided to manage her deep perioral wrinkles by deep peeling using the Baker formula and concomitantly to use autologous fat injection to augment her thin lips.
Results The healing of our patient after these two interventions was uneventful, and satisfactory results have been obtained.
Conclusion Based on our experience, this intervention may be suggested for patients suffering from scleroderma after a detailed explanation of the possible wound healing difficulties is provided to the patients.  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