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   2944270篇
  免费   229595篇
  国内免费   5892篇
耳鼻咽喉   42592篇
儿科学   91362篇
妇产科学   80670篇
基础医学   414008篇
口腔科学   83999篇
临床医学   264140篇
内科学   577307篇
皮肤病学   60428篇
神经病学   245442篇
特种医学   117814篇
外国民族医学   1129篇
外科学   449447篇
综合类   68543篇
现状与发展   1篇
一般理论   1169篇
预防医学   233560篇
眼科学   69271篇
药学   218558篇
  4篇
中国医学   5550篇
肿瘤学   154763篇
  2018年   29972篇
  2016年   25502篇
  2015年   28849篇
  2014年   41554篇
  2013年   63503篇
  2012年   85507篇
  2011年   90315篇
  2010年   53574篇
  2009年   51435篇
  2008年   86048篇
  2007年   91387篇
  2006年   92257篇
  2005年   90083篇
  2004年   86574篇
  2003年   83727篇
  2002年   82540篇
  2001年   135243篇
  2000年   139585篇
  1999年   118252篇
  1998年   34096篇
  1997年   31060篇
  1996年   30836篇
  1995年   29623篇
  1994年   27821篇
  1993年   26044篇
  1992年   94853篇
  1991年   91531篇
  1990年   88547篇
  1989年   85349篇
  1988年   79371篇
  1987年   78132篇
  1986年   74353篇
  1985年   70871篇
  1984年   53597篇
  1983年   45739篇
  1982年   27953篇
  1981年   24738篇
  1980年   23309篇
  1979年   50272篇
  1978年   35267篇
  1977年   29869篇
  1976年   28038篇
  1975年   29784篇
  1974年   36482篇
  1973年   34700篇
  1972年   32618篇
  1971年   30131篇
  1970年   28517篇
  1969年   26611篇
  1968年   24533篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.  相似文献   
82.
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.  相似文献   
83.
84.
Endoscopic clips have been used mainly for control of gastrointestinal (GI) bleeding and occasionally for closure of GI perforations. However, closure of spontaneous esophageal perforation (Boerhaave's syndrome) by clipping has not been reported. We described successful non-surgical closure of spontaneous esophageal perforation by endoscopic clipping in a patient with bilateral pyopneumothorax and septicemia.  相似文献   
85.
86.
87.
88.
89.
90.
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