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   874257篇
  免费   72775篇
  国内免费   1858篇
耳鼻咽喉   12929篇
儿科学   25052篇
妇产科学   25346篇
基础医学   125964篇
口腔科学   25802篇
临床医学   76942篇
内科学   167198篇
皮肤病学   17142篇
神经病学   71359篇
特种医学   35612篇
外国民族医学   173篇
外科学   137669篇
综合类   24919篇
现状与发展   2篇
一般理论   275篇
预防医学   68255篇
眼科学   20820篇
药学   65733篇
中国医学   1597篇
肿瘤学   46101篇
  2018年   7540篇
  2015年   7921篇
  2014年   11406篇
  2013年   17166篇
  2012年   23371篇
  2011年   24455篇
  2010年   14220篇
  2009年   13346篇
  2008年   23151篇
  2007年   25210篇
  2006年   25080篇
  2005年   24731篇
  2004年   24304篇
  2003年   23389篇
  2002年   22421篇
  2001年   36317篇
  2000年   36972篇
  1999年   31334篇
  1998年   9406篇
  1997年   8687篇
  1996年   8621篇
  1995年   8180篇
  1994年   7845篇
  1992年   27035篇
  1991年   26420篇
  1990年   25943篇
  1989年   24984篇
  1988年   23477篇
  1987年   23149篇
  1986年   21966篇
  1985年   21324篇
  1984年   16540篇
  1983年   14153篇
  1982年   8982篇
  1981年   8309篇
  1980年   7778篇
  1979年   16900篇
  1978年   12225篇
  1977年   10282篇
  1976年   9444篇
  1975年   10242篇
  1974年   12756篇
  1973年   12266篇
  1972年   11641篇
  1971年   10755篇
  1970年   10309篇
  1969年   9988篇
  1968年   8964篇
  1967年   8295篇
  1966年   7721篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances.  相似文献   
12.
13.
14.
Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicatedin advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-EastIndia and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examinationfrom September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational(epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved,standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters.Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantlyhigher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patientswith well differentiated histology and was more common in patients with stage II and III diseases, but neither of theassociations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours(56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patientswith locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlatedsignificantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expressionis recommended to provide a therapeutic advantage in Indian patients.  相似文献   
15.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
16.
17.
18.
19.
20.
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