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   15548篇
  免费   977篇
  国内免费   188篇
耳鼻咽喉   382篇
儿科学   199篇
妇产科学   288篇
基础医学   2696篇
口腔科学   294篇
临床医学   1205篇
内科学   3067篇
皮肤病学   438篇
神经病学   1181篇
特种医学   1043篇
外科学   2081篇
综合类   71篇
现状与发展   3篇
一般理论   10篇
预防医学   607篇
眼科学   428篇
药学   1254篇
中国医学   153篇
肿瘤学   1313篇
  2024年   12篇
  2023年   133篇
  2022年   370篇
  2021年   661篇
  2020年   268篇
  2019年   439篇
  2018年   524篇
  2017年   409篇
  2016年   611篇
  2015年   872篇
  2014年   950篇
  2013年   1043篇
  2012年   1577篇
  2011年   1421篇
  2010年   838篇
  2009年   706篇
  2008年   891篇
  2007年   907篇
  2006年   769篇
  2005年   624篇
  2004年   517篇
  2003年   467篇
  2002年   380篇
  2001年   293篇
  2000年   237篇
  1999年   174篇
  1998年   71篇
  1997年   55篇
  1996年   34篇
  1995年   36篇
  1994年   24篇
  1993年   30篇
  1992年   38篇
  1991年   39篇
  1990年   34篇
  1989年   36篇
  1988年   28篇
  1987年   32篇
  1986年   17篇
  1985年   15篇
  1984年   10篇
  1983年   10篇
  1981年   14篇
  1980年   7篇
  1979年   14篇
  1978年   10篇
  1977年   10篇
  1976年   10篇
  1975年   9篇
  1973年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Background/AimsThe worldwide coronavirus disease 2019 pandemic has led endoscopists to use personal protective equipment (PPE) for infection prevention. This study aimed to investigate whether wearing a face shield as PPE affects the quality of colonoscopy.MethodsWe reviewed the medical records and colonoscopy findings of patients who underwent colonoscopies at Asan Medical Center, Korea from March 10 to May 31, 2020. The colonoscopies in this study were performed by five gastroenterology fellows and four expert endoscopists. We compared colonoscopy quality indicators, such as withdrawal time, adenoma detection rate (ADR), mean number of adenomas per colonoscopy (APC), polypectomy time, and polypectomy adverse events, both before and after face shields were added as PPE on April 13, 2020.ResultsOf the 1,344 colonoscopies analyzed, 715 and 629 were performed before and after the introduction of face shields, respectively. The median withdrawal time was similar between the face shield and no-face shield groups (8.72 minutes vs 8.68 minutes, p=0.816), as was the ADR (41.5% vs 39.8%, p=0.605) and APC (0.72 vs 0.77, p=0.510). Polypectomy-associated quality indicators, such as polypectomy time and polypectomy adverse events were also not different between the groups. Quality indicators were not different between the face shield and no-face shield groups of gastroenterology fellows, or of expert endoscopists.ConclusionsColonoscopy performance was not unfavorably affected by the use of a face shield. PPE, including face shields, can be recommended without a concern about colonoscopy quality deterioration.  相似文献   
72.
Type 1 diabetes (T1D) is caused by dysregulation of the immune system in the pancreatic islets, which eventually leads to insulin-producing pancreatic β-cell death and destabilization of glucose homeostasis. One of the major characteristics of T1D pathogenesis is the production of inflammatory mediators by macrophages that result in destruction or damage of pancreatic β-cells. In this study the inflammatory microenvironment of T1D was simulated with RAW264.7 cells and MIN6 cells, acting as macrophages and pancreatic β-cells respectably. In this setting, peroxiredoxin-1, an anti-oxidant enzyme was knocked down to observe its functions in the pathogenesis of T1D. RAW264.7 cells were primed with lipopolysaccharide and co-cultured with MIN6 cells while PRX-1 was knocked down in one or both cell types. Our results suggest that hindrance of PRX-1 activity or the deficiency of this enzyme in inflammatory conditions negatively affects pancreatic β-cell survival. The observed decrease in viability of MIN6 cells seems to be caused by nitric oxide production. Additionally, it seems that PRX-1 affects previously reported protective activity of IL-6 in pancreatic β cells as well. These results signify new, undiscovered roles for PRX-1 in inflammatory conditions and may contribute toward our understanding of autoimmunity.  相似文献   
73.
74.
75.
76.
A solid-pseudopapillary tumor (SPT) of the pancreas is known as a low grade malignant tumor with a good prognosis; therefore, surgical intervention is necessary. A 14-year-old boy presented with a large pancreatic SPT and three hepatic metastases. The patient and his family refused surgery. Two serial follow-up CT scans over a period of 13 years demonstrated almost complete disappearance of the pancreatic tumor and three hepatic metastases without relevant treatment. Although there have been a few reports of spontaneous healing of SPT, there has been no report regarding spontaneous disappearance of SPT and distant metastasis. Herein, we report on the spontaneous regression of a large SPT and the disappearance of three hepatic metastases.  相似文献   
77.
Dysembryoplastic neuroepithelial tumors (DNETs) arise mostly in the supratentorial cerebral cortex. A very rare case of intraventricular DNET with diffuse ependymal involvement, which causes spinal drop metastasis, is presented.  相似文献   
78.
79.
80.
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