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   3368946篇
  免费   250056篇
  国内免费   8849篇
耳鼻咽喉   45572篇
儿科学   110133篇
妇产科学   91884篇
基础医学   473921篇
口腔科学   94304篇
临床医学   308966篇
内科学   661820篇
皮肤病学   77237篇
神经病学   277790篇
特种医学   130971篇
外国民族医学   952篇
外科学   503442篇
综合类   72831篇
现状与发展   5篇
一般理论   1292篇
预防医学   265960篇
眼科学   74816篇
药学   246784篇
  11篇
中国医学   6629篇
肿瘤学   182531篇
  2019年   26126篇
  2018年   36876篇
  2017年   28287篇
  2016年   32566篇
  2015年   36721篇
  2014年   50877篇
  2013年   76851篇
  2012年   101674篇
  2011年   107856篇
  2010年   64973篇
  2009年   62224篇
  2008年   100600篇
  2007年   107082篇
  2006年   108881篇
  2005年   104706篇
  2004年   100904篇
  2003年   97338篇
  2002年   93743篇
  2001年   162016篇
  2000年   166452篇
  1999年   140020篇
  1998年   40422篇
  1997年   35952篇
  1996年   36403篇
  1995年   35380篇
  1994年   32651篇
  1993年   30538篇
  1992年   110368篇
  1991年   106573篇
  1990年   103241篇
  1989年   99383篇
  1988年   91310篇
  1987年   89717篇
  1986年   84409篇
  1985年   80658篇
  1984年   60427篇
  1983年   51134篇
  1982年   30395篇
  1981年   27232篇
  1979年   53910篇
  1978年   38304篇
  1977年   32331篇
  1976年   30028篇
  1975年   32046篇
  1974年   38026篇
  1973年   36278篇
  1972年   33874篇
  1971年   31445篇
  1970年   28922篇
  1969年   27515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