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   2216篇
  免费   75篇
  国内免费   6篇
耳鼻咽喉   23篇
儿科学   19篇
妇产科学   7篇
基础医学   316篇
口腔科学   112篇
临床医学   191篇
内科学   466篇
皮肤病学   40篇
神经病学   405篇
特种医学   89篇
外科学   248篇
综合类   16篇
一般理论   1篇
预防医学   70篇
眼科学   19篇
药学   144篇
中国医学   2篇
肿瘤学   129篇
  2023年   9篇
  2022年   6篇
  2021年   22篇
  2020年   20篇
  2019年   22篇
  2018年   48篇
  2017年   12篇
  2016年   32篇
  2015年   33篇
  2014年   62篇
  2013年   68篇
  2012年   137篇
  2011年   153篇
  2010年   89篇
  2009年   84篇
  2008年   136篇
  2007年   166篇
  2006年   170篇
  2005年   190篇
  2004年   151篇
  2003年   166篇
  2002年   143篇
  2001年   40篇
  2000年   28篇
  1999年   31篇
  1998年   33篇
  1997年   36篇
  1996年   29篇
  1995年   21篇
  1994年   16篇
  1993年   23篇
  1992年   13篇
  1991年   5篇
  1990年   12篇
  1989年   4篇
  1988年   7篇
  1987年   14篇
  1986年   7篇
  1985年   3篇
  1984年   3篇
  1983年   7篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1977年   5篇
  1976年   4篇
  1975年   4篇
  1974年   5篇
  1970年   3篇
排序方式: 共有2297条查询结果,搜索用时 390 毫秒
31.
ABSTRACT: BACKGROUND: Heart failure is likely to be particularly prevalent in the nursing home population, but reliable data about the prevalence of heart failure in nursing homes are lacking. Therefore the aims of this study are to investigate (a) the prevalence and management of heart failure in nursing home residents and (b) the relation between heart failure and care dependency as well as heart failure and quality of life in nursing home residents METHODS: Nursing home residents in the southern part of the Netherlands, aged over 65 years and receiving long-term somatic or psychogeriatric care will be included in the study. A panel of two cardiologists and a geriatrician will diagnose heart failure based on data collected from actual clinical examinations (including history, physical examination, ECG, cardiac markers and echocardiography), patient records and questionnaires. Care dependency will be measured using the Care Dependency Scale. To measure the quality of life of the participating residents, the Qualidem will be used for psychogeriatric residents and the SF-12 and VAS for somatic residents. CONCLUSION: The study will provide an insight into the actual prevalence and management of heart failure in nursing home residents as well as their quality of life and care dependency. Trial registration: Dutch trial register NTR2663.  相似文献   
32.
33.
34.
Fibronectin is ubiquitously expressed in the extracellular matrix, and experimental evidence has shown that it modulates blood vessel formation. The relative contribution of local and circulating fibronectin to blood vessel formation in vivo remains unknown despite evidence for unexpected roles of circulating fibronectin in various diseases. Using transgenic mouse models, we established that circulating fibronectin facilitates the growth of bone metastases by enhancing blood vessel formation and maturation. This effect is more relevant than that of fibronectin produced by endothelial cells and pericytes, which only exert a small additive effect on vessel maturation. Circulating fibronectin enhances its local production in tumors through a positive feedback loop and increases the amount of vascular endothelial growth factor (VEGF) retained in the matrix. Both fibronectin and VEGF then cooperate to stimulate blood vessel formation. Fibronectin content in the tumor correlates with the number of blood vessels and tumor growth in the mouse models. Consistent with these results, examination of three separate arrays from patients with breast and prostate cancers revealed that a high staining intensity for fibronectin in tumors is associated with increased mortality. These results establish that circulating fibronectin modulates blood vessel formation and tumor growth by modifying the amount of and the response to VEGF. Furthermore, determination of the fibronectin content can serve as a prognostic biomarker for breast and prostate cancers and possibly other cancers.  相似文献   
35.
36.
37.
38.
An 18-year-old long-term Norwegian resident of Somali origin was submitted to hospital with bloody diarrhoea, fever, weight loss and abdominal pain. On initial colonoscopy, colitis with segmental appearance was seen. Apart from a single polymerase chain reaction (PCR) from gastric aspirate staining, PCR and culture for acid-fast bacilli revealed negative results from the multiple samples taken including sputum, gastric fluid, stool, urine and intestinal mucosa. On physical examination and CT scan, there was no evidence of ascites, lymph node enlargement or pathologic pulmonary findings. Although the diagnosis was uncertain, tuberculostatic therapy was initiated. As the conformational testing of the PCR and the microbiological work-up remained negative and the patient's condition did not improve, tuberculostatic treatment was stopped and Crohn's disease was stated as the most likely diagnosis. Although the patient improved clinically under therapy with prednisolone, newly appearing fistulas deriving from the ascending colon were noted on follow-up. Thus tuberculostatic treatment was restarted. However, signs of an acute abdomen appeared and laparotomy was performed, thereby revealing a peritoneal spread of nodules. Resection of the ileum and ascending colon was performed. Diagnosis of intestinal tuberculosis with peritoneal spread was made by histology from resected bowel specimens showing caseating granulomas and a positive PCR result. The patient's condition improved after resection of the highly inflamed bowel segments and tuberculostatic therapy. Our case report shows the difficulty of proving intestinal tuberculosis by microbiological testing, macroscopic features on colonoscopy, histology, imaging such as CT scan and by empirical therapy. Therefore, in cases of colonic inflammation, where intestinal tuberculosis is an important differential diagnosis, a more aggressive diagnostic approach such as explorative laparoscopy should be considered.  相似文献   
39.
40.
BACKGROUND: Toxic megacolon is a life-threatening complication most commonly observed in patients with ulcerative colitis or Crohn's disease that is characterized by total or segmental nonobstructive colonic dilatation of at least 6 cm on plain abdominal films associated with systemic toxicity. CASE REPORT: We report an unusual case of fulminant steroid-refractory ulcerative colitis complicated by toxic megacolon treated successfully with the immunosuppressant tacrolimus. CONCLUSION: Tacrolimus administration induced clinical remission and bridged the time interval, until the standard immunosuppressant azathioprine could maintain clinical remission, thereby avoiding eminent emergency colectomy.  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