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   3390582篇
  免费   251886篇
  国内免费   8869篇
耳鼻咽喉   45831篇
儿科学   110759篇
妇产科学   92327篇
基础医学   476743篇
口腔科学   94935篇
临床医学   311744篇
内科学   665649篇
皮肤病学   77543篇
神经病学   280031篇
特种医学   131850篇
外国民族医学   953篇
外科学   506140篇
综合类   73221篇
现状与发展   5篇
一般理论   1320篇
预防医学   268321篇
眼科学   75372篇
药学   248251篇
  13篇
中国医学   6657篇
肿瘤学   183672篇
  2019年   26401篇
  2018年   37198篇
  2017年   28577篇
  2016年   32828篇
  2015年   37035篇
  2014年   51312篇
  2013年   77605篇
  2012年   102670篇
  2011年   108944篇
  2010年   65577篇
  2009年   62767篇
  2008年   101518篇
  2007年   108220篇
  2006年   109957篇
  2005年   105660篇
  2004年   101887篇
  2003年   98229篇
  2002年   94689篇
  2001年   162454篇
  2000年   166916篇
  1999年   140436篇
  1998年   40667篇
  1997年   36168篇
  1996年   36619篇
  1995年   35574篇
  1994年   32828篇
  1993年   30691篇
  1992年   110748篇
  1991年   106967篇
  1990年   103611篇
  1989年   99783篇
  1988年   91598篇
  1987年   90088篇
  1986年   84770篇
  1985年   81032篇
  1984年   60702篇
  1983年   51376篇
  1982年   30599篇
  1981年   27405篇
  1979年   54210篇
  1978年   38562篇
  1977年   32549篇
  1976年   30257篇
  1975年   32236篇
  1974年   38275篇
  1973年   36495篇
  1972年   34076篇
  1971年   31626篇
  1970年   29070篇
  1969年   27659篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Neu-Laxova syndrome (NLS) is a rare autosomal recessive syndrome, characterized by severe intrauterine growth retardation (IUGR), microcephaly, abnormal brain development, oedema and ichthyosis. It was first reported in 1971 by Neu et al. (Pediatrics 47: 610-612) and since then no more than 60 cases have been reported. A newborn girl delivered from a 29-year-old healthy mother was admitted to hospital with a thick membrane covering her body and dismorphic appearance. The diagnosis of NLS was made according to characteristic features. The syndrome is known to have a poor prognosis and the baby lived for 9 weeks. This case is one of the longest living cases of NLS and the fourth case reported from Turkey.  相似文献   
83.
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   
84.
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   
85.
86.
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   
87.
88.
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon  相似文献   
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