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   14855篇
  免费   3015篇
  国内免费   295篇
耳鼻咽喉   728篇
儿科学   326篇
妇产科学   345篇
基础医学   897篇
口腔科学   496篇
临床医学   2149篇
内科学   3359篇
皮肤病学   580篇
神经病学   1477篇
特种医学   812篇
外科学   3562篇
综合类   136篇
现状与发展   2篇
一般理论   1篇
预防医学   1046篇
眼科学   393篇
药学   399篇
中国医学   54篇
肿瘤学   1403篇
  2024年   100篇
  2023年   529篇
  2022年   229篇
  2021年   450篇
  2020年   799篇
  2019年   315篇
  2018年   778篇
  2017年   717篇
  2016年   917篇
  2015年   872篇
  2014年   1163篇
  2013年   1312篇
  2012年   750篇
  2011年   619篇
  2010年   820篇
  2009年   1005篇
  2008年   556篇
  2007年   440篇
  2006年   531篇
  2005年   368篇
  2004年   259篇
  2003年   244篇
  2002年   236篇
  2001年   280篇
  2000年   226篇
  1999年   233篇
  1998年   279篇
  1997年   290篇
  1996年   336篇
  1995年   295篇
  1994年   191篇
  1993年   137篇
  1992年   157篇
  1991年   159篇
  1990年   96篇
  1989年   149篇
  1988年   120篇
  1987年   111篇
  1986年   119篇
  1985年   94篇
  1984年   98篇
  1983年   88篇
  1982年   83篇
  1981年   60篇
  1980年   59篇
  1979年   40篇
  1978年   57篇
  1977年   50篇
  1975年   47篇
  1972年   45篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
Ultrasound scans of 51 consecutive patients with gallbladder wall thickening were reviewed, and specific sonographic features were correlated with surgical and clinical follow-up. Two patterns of thickening were identified as specific indicators of the presence or absence of acute cholecystitis. "Striated" wall thickening, consisting of several alternating, irregular, discontinuous, lucent and echogenic bands, was seen in eight of 13 patients (62%) with acute cholecystitis. This pattern was not encountered in any of the patients who did not have acute cholecystitis. Conversely, "three-layer" thickening, consisting of a single circumferential lucent zone between two relatively uniform echogenic layers, was seen in only one of 13 patients (8%) with acute cholecystitis but in 11 of 38 patients (29%) with other diagnoses. Other abnormalities, including the presence of intramural echogenic foci and wall irregularities, were more frequently seen in patients with acute cholecystitis but were not as helpful. Use of these features may suggest or help exclude a diagnosis of acute cholecystitis in those patients in whom the cause of gallbladder wall thickening is otherwise not apparent.  相似文献   
104.
105.

Sexual minority emerging adults are more likely to engage in suicidal ideation than their heterosexual counterparts. Experiences of homophobic violence are associated with suicidal ideation. Yet, the specific mechanisms linking homophobic violence to suicidal ideation remain unclear. Entrapment and social belongingness were tested to determine their relevance for understanding the link between homophobic violence and suicidal ideation. A sample of sexual minority Dutch emerging adults (N?=?675; ages 18–29, M?=?21.93 years, SD?=?3.20) were recruited through online platforms and flyers. Homophobic violence was expected to be positively associated with suicidal ideation and entrapment. The association between homophobic violence and suicidal ideation was expected to be indirectly linked through entrapment. We explored whether various sources of social belongingness moderated the path between entrapment and suicidal ideation and whether those sources of social belongingness moderated the indirect effect of homophobic violence on suicidal ideation through entrapment. Results showed that homophobic violence and entrapment were positively associated with suicidal ideation and that family belongingness was negatively associated with suicidal ideation. Homophobic violence and suicidal ideation were not indirectly linked through entrapment. The interaction effect between entrapment and family belongingness was significant, suggesting that, on average, the effect of entrapment on suicidal ideation decreased when family belongingness was high. These results suggest that family belongingness may reduce the association between entrapment and suicidal ideation while adjusting for homophonic violence. Reducing entrapment and improving family belongingness may be useful targets for programs aimed at preventing suicidal ideation among sexual minority emerging adults.

  相似文献   
106.
107.
108.
109.
The massive weight loss produced by bariatric surgical procedures on the morbidly obese can result in gross redundancy of abdominal and trunk skin. Standard abdominoplasty procedures may be insufficient to correct this debilitating deformity. A radical version of the “Fleur-de-Lis” abdominoplasty has been carried out on 45 such patients, with good cosmetic and functional results and low morbidity.  相似文献   
110.
Cyclic stretch has been demonstrated to induce proliferative and secretory activities by cultured arterial endothelial and smooth muscle cells, cellular processes that contribute to the development of intimal hyperplasia. A model of an end-to-side anastomosis was developed to examine the hypothesis that regions of the artery at such anastomoses are subjected to facally increased cyclic stretch, which may stimulate the development of intimal hyperplasia. Polytetrafluoroethylene grafts were anastomosed end to side to latex rubber tubes that have elastic properties similar to those of the human femoral artery. Pulse waves with physiologic pressure, rate, and contour were applied, and systolic and diastolic diameters were measured in two planes at longitudinal intervals. Circumferential strain imposed on the latex artery was calculated at each interval. Strain imposed perpendicular to the suture line was also measured. Circumferential strain was consistently maximal at a distinct region of the artery along the proximal third of the anatomosis (6.0±1.1% vs. 3.3±0.5% at other regions of the artery). The maximal strain across the suture line was found at precisely the same region (3.9±0.3% vs. 2.0±0.4%). The anastomotic region of the recipient artery in a distal end-to-side anastomosis is subjected to cyclic circumferential strains two times greater than those experienced by the remainder of the artery. This corresponds to a common location of intimal hyperplasia. Such strains may be a stimulus for intimal hyperplasia.Presented at the Seventeenth Annual Meeting of the Peripheral Vascular Surgery Society, June 7, 1992, Chicago, Ill.  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