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   3370068篇
  免费   250053篇
  国内免费   8849篇
耳鼻咽喉   45579篇
儿科学   110121篇
妇产科学   91800篇
基础医学   474037篇
口腔科学   94279篇
临床医学   308985篇
内科学   662167篇
皮肤病学   77213篇
神经病学   277860篇
特种医学   130995篇
外国民族医学   952篇
外科学   503910篇
综合类   72822篇
现状与发展   5篇
一般理论   1290篇
预防医学   265894篇
眼科学   74910篇
药学   246860篇
  11篇
中国医学   6628篇
肿瘤学   182652篇
  2019年   26127篇
  2018年   36886篇
  2017年   28290篇
  2016年   32574篇
  2015年   36734篇
  2014年   50899篇
  2013年   76895篇
  2012年   101715篇
  2011年   107926篇
  2010年   65029篇
  2009年   62263篇
  2008年   100652篇
  2007年   107160篇
  2006年   108976篇
  2005年   104795篇
  2004年   101022篇
  2003年   97431篇
  2002年   93887篇
  2001年   162017篇
  2000年   166444篇
  1999年   140039篇
  1998年   40454篇
  1997年   35994篇
  1996年   36438篇
  1995年   35408篇
  1994年   32670篇
  1993年   30556篇
  1992年   110377篇
  1991年   106567篇
  1990年   103235篇
  1989年   99378篇
  1988年   91307篇
  1987年   89717篇
  1986年   84407篇
  1985年   80663篇
  1984年   60423篇
  1983年   51138篇
  1982年   30400篇
  1981年   27229篇
  1979年   53904篇
  1978年   38304篇
  1977年   32332篇
  1976年   30017篇
  1975年   32041篇
  1974年   38019篇
  1973年   36265篇
  1972年   33876篇
  1971年   31437篇
  1970年   28913篇
  1969年   27513篇
排序方式: 共有10000条查询结果,搜索用时 0 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