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   40874篇
  免费   2040篇
  国内免费   205篇
耳鼻咽喉   547篇
儿科学   755篇
妇产科学   555篇
基础医学   5053篇
口腔科学   1247篇
临床医学   2790篇
内科学   9364篇
皮肤病学   903篇
神经病学   3704篇
特种医学   2002篇
外国民族医学   1篇
外科学   6668篇
综合类   132篇
一般理论   7篇
预防医学   1228篇
眼科学   921篇
药学   2554篇
中国医学   80篇
肿瘤学   4608篇
  2023年   205篇
  2021年   736篇
  2020年   434篇
  2019年   548篇
  2018年   741篇
  2017年   597篇
  2016年   740篇
  2015年   730篇
  2014年   958篇
  2013年   1192篇
  2012年   1976篇
  2011年   2076篇
  2010年   1230篇
  2009年   1053篇
  2008年   1874篇
  2007年   2116篇
  2006年   1933篇
  2005年   1868篇
  2004年   1854篇
  2003年   1764篇
  2002年   1756篇
  2001年   1369篇
  2000年   1461篇
  1999年   1323篇
  1998年   550篇
  1997年   431篇
  1996年   375篇
  1995年   331篇
  1994年   346篇
  1993年   307篇
  1992年   1017篇
  1991年   864篇
  1990年   824篇
  1989年   821篇
  1988年   783篇
  1987年   771篇
  1986年   674篇
  1985年   629篇
  1984年   437篇
  1983年   355篇
  1982年   155篇
  1979年   298篇
  1978年   211篇
  1977年   187篇
  1974年   191篇
  1973年   163篇
  1972年   161篇
  1971年   183篇
  1970年   156篇
  1969年   176篇
排序方式: 共有10000条查询结果,搜索用时 27 毫秒
1.
2.
3.
4.
Background: Few new Residency Program Directors (PD) are formally trained for the demands and responsibilities of the leadership aspect of their role. Currently, there are no comprehensive frameworks that describe specific leadership competencies that can inform PD self-reflection or faculty development.

Methods: The authors developed a Postgraduate Program Director Competency Inventory (PPDCI) in order to frame the performance of PDs for a multisource feedback (MSF) program. The development of the PPDCI occurred in five phases which involved: development of an initial inventory, implementation of a key informant survey of national opinion leaders, execution of a validity survey with postgraduate education leaders and committee members and implementation of a further refined inventory with 17 PD and 147 raters as part of a pilot MSF program.

Outcomes: Five distinct domains of leadership competence were identified which included: Communication and relationship management, leadership, professionalism and self-management, environmental engagement, and management skills and knowledge. The content validity of the PPDCI was endorsed by 85% of the key informants. The validity survey indicated strong endorsement of the PPDCI domains and recognition of its utility for both orientation of new PD as well as a frame for self-assessment. The pilot MSF program yielded a further refined and reduced inventory of 26 items of competence as well as recommendations for its utility.

Conclusions: Use of this leadership inventory has the potential to ensure effective leadership of postgraduate programs.  相似文献   
5.
We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.  相似文献   
6.
7.
Kohmoto  Tomohiro  Masuda  Kiyoshi  Shoda  Katsutoshi  Takahashi  Rizu  Ujiro  Sae  Tange  Shoichiro  Ichikawa  Daisuke  Otsuji  Eigo  Imoto  Issei 《Gastric cancer》2020,23(3):403-417
Gastric Cancer - We aimed to identify novel tumor-promoting drivers highly expressed in gastric cancer (GC) that contribute to worsened prognosis in affected patients. Genes whose expression was...  相似文献   
8.
neurogenetics - Mediator (MED) is a key regulator of protein-coding gene expression, and mutations in MED subunits are associated with a broad spectrum of diseases. Because mutations in MED17...  相似文献   
9.
10.
We prospectively evaluated the effectiveness of contrast-enhanced ultrasonography (CEUS) for differentiation of benign versus malignant portal vein thrombosis (PVT). We studied a total of 43 patients with chronic liver disease, hepatocellular carcinoma-suggestive nodules and confirmed PVT, in whom the nature of the PVT was confirmed by follow-up imaging (US, computed tomography and/or magnetic resonance imaging) performed up to 6 mo after CEUS. PVT was assessed by US, Doppler US and CEUS with respect to vessel wall disruption and/or invasion, color Doppler vascularization, pulsed Doppler vascularization pattern and CEUS enhancement and vascularization pattern, and thrombi were classified as benign or malignant based on these findings. Follow-up studies revealed malignant PVT in 22 of the 43 patients (51%) and benign PVT in 21 patients (49%). CEUS findings were consistent with follow-up studies in 41 of the 43 patients (95%), with κ?=?0.903 (p < 0.0001), sensitivity?=?91% and specificity?=?100%, indicating that CEUS can be confidently used to differentiate benign from malignant portal vein thrombosis in the setting of chronic liver disease.  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