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   1406篇
  免费   165篇
  国内免费   49篇
耳鼻咽喉   9篇
儿科学   104篇
妇产科学   21篇
基础医学   127篇
口腔科学   46篇
临床医学   136篇
内科学   439篇
皮肤病学   30篇
神经病学   26篇
特种医学   197篇
外科学   96篇
综合类   105篇
预防医学   124篇
眼科学   12篇
药学   73篇
中国医学   4篇
肿瘤学   71篇
  2023年   17篇
  2022年   14篇
  2021年   30篇
  2020年   23篇
  2019年   13篇
  2018年   24篇
  2017年   48篇
  2016年   39篇
  2015年   33篇
  2014年   68篇
  2013年   87篇
  2012年   36篇
  2011年   41篇
  2010年   70篇
  2009年   77篇
  2008年   38篇
  2007年   70篇
  2006年   47篇
  2005年   25篇
  2004年   28篇
  2003年   19篇
  2002年   15篇
  2001年   37篇
  2000年   35篇
  1999年   32篇
  1998年   86篇
  1997年   67篇
  1996年   59篇
  1995年   52篇
  1994年   48篇
  1993年   47篇
  1992年   20篇
  1991年   12篇
  1990年   25篇
  1989年   30篇
  1988年   27篇
  1987年   18篇
  1986年   26篇
  1985年   21篇
  1984年   10篇
  1983年   16篇
  1982年   10篇
  1981年   5篇
  1980年   9篇
  1979年   4篇
  1978年   10篇
  1977年   6篇
  1976年   12篇
  1975年   11篇
  1972年   4篇
排序方式: 共有1620条查询结果,搜索用时 15 毫秒
1.
2.
Calciphylaxis – a topical overview   总被引:3,自引:0,他引:3  
'Calciphylaxis', a calcification syndrome associated with ischaemic cutaneous necrosis, is acquired naturally in humans in disease states. It is a life and limb-threatening complication, usually observed in patients with renal disease and secondary hyperparathyroidism, but known to occur in the absence of renal or parathyroid disease. The reported mortality rate, which ranges from 60-80%, relates to wound infection, sepsis and organ failure. It is a small-vessel vasculopathy, which is estimated to occur in about 4% of haemodialysis patients. Clinically, violaceous, reticulate areas of cutaneous necrosis and eschar may be evident, particularly in the extremities. In addition to the clinical picture, a raised calcium phosphorous product, an elevated parathyroid hormone level, radiographic evidence of vessel and soft-tissue calcification and the finding of mural calcification affecting small arteries and arterioles on histopathology help to confirm the diagnosis of this entity which generally has a poor prognosis. A high index of suspicion and an active multidisciplinary management approach, with rigorous attention to wound care and prevention of sepsis, are vital in the management of these patients. In this overview, we discuss the pathophysiology, clinical features and associations, risk factors, diagnosis and management issues relating to calciphylaxis.  相似文献   
3.
We investigated whether weight loss decreases the waist-hip ratio (WHR) in overweight men and women, and whether changes in WHR relates to change in cardiovascular risk factors, independent of change in weight. Weight loss correlated significantly with decreases in the circumference of the waist and hips, and decreases in WHR in men and women. At comparable levels of weight loss, men had greater decreases in the waist, and smaller decreases in the hips than women, resulting in greater decreases in WHR. Cardiovascular risk factors improved significantly with weight loss. However, after controlling for weight loss, there was no evidence that change in WHR or change in circumference measures were related to change in risk factors. These data suggest that WHR is modifiable by weight loss, especially in men, but that change in WHR may not be independently related to changes in cardiovascular risk factors.  相似文献   
4.

Backround  

Diverticulosis is a common disease in the western society with an incidence of 33–66%. 10–25% of these patients will develop diverticulitis. In order to prevent a high-risk acute operation it is advised to perform elective sigmoid resection after two episodes of diverticulitis in the elderly patient or after one episode in the younger (< 50 years) patient. Open sigmoid resection is still the gold standard, but laparoscopic colon resections seem to have certain advantages over open procedures. On the other hand, a double blind investigation has never been performed. The Sigma-trial is designed to evaluate the presumed advantages of laparoscopic over open sigmoid resections in patients with symptomatic diverticulitis.  相似文献   
5.
6.
7.
8.
A decade ago, less than one-half of the family practice (FP) residency programs surveyed provided a defined rotation in neurology. To learn how neurology is currently being taught in FP residencies, we sent questionnaires to 384 approved FP residencies in the United States, receiving responses from 241 (63%). Seventy-eight percent provide a defined rotation in neurology, usually in the form of a preceptorship with a community neurologist, and 57% systematically present the core curriculum recommended by the American Academy of Neurology and the American Academy of Family Physicians in 1987. Asked about the level of cooperation they encounter in recruiting neurologists to teach, 54% of the respondents reported "too little" or "no" cooperation from academic neurologists, while just 20% reported these responses in regard to community neurologists. Most (87%) reported that involvement in the residency program leads to increased patient referrals for the participating neurologist. Most (81%) respondents would welcome more participation by neurologists.  相似文献   
9.
OBJECTIVE: Lymphoepithelioma-like carcinoma (LELC) is an undifferentiated carcinoma with a dense lymphoid stroma. It has been reported in diverse organs and shows variable association with Epstein-Barr virus (EBV). Only a few EBV positive cases have been observed in the hepatobiliary system, all of which were considered to be cholangiocarcinomas. We report a unique case of hepatocellular LELC arising in a cirrhotic liver with EBV demonstrated in the tumor cells. METHODS AND RESULTS: A 39-year-old Hispanic female underwent an orthotopic liver transplant for end stage liver disease secondary to chronic hepatitis C. A high-grade hepatocellular carcinoma with a dense lymphocytic infiltrate was found in the explant as well as in a portal lymph node. Three months posttransplant, the patient developed numerous hepatic nodules with enlarged periaortic and portacaval lymph nodes. Biopsy of the hepatic nodules showed a recurrent hepatocellular carcinoma devoid of a dense lymphocytic infiltrate. Both the primary and recurrent tumors were positive for EBV by molecular studies. The patient eventually expired from liver failure over a 6-week period. CONCLUSION: This case represents the first report of EBV-positive hepatocellular LELC. It is particularly interesting given the precipitous clinical outcome, which was possibly related to immunosuppresive therapy.  相似文献   
10.
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