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   2457篇
  免费   131篇
  国内免费   28篇
耳鼻咽喉   80篇
儿科学   143篇
妇产科学   110篇
基础医学   171篇
口腔科学   100篇
临床医学   228篇
内科学   621篇
皮肤病学   53篇
神经病学   140篇
特种医学   69篇
外科学   550篇
综合类   38篇
预防医学   62篇
眼科学   92篇
药学   72篇
中国医学   2篇
肿瘤学   85篇
  2024年   1篇
  2023年   13篇
  2022年   19篇
  2021年   54篇
  2020年   40篇
  2019年   56篇
  2018年   71篇
  2017年   57篇
  2016年   94篇
  2015年   137篇
  2014年   121篇
  2013年   144篇
  2012年   208篇
  2011年   203篇
  2010年   123篇
  2009年   100篇
  2008年   193篇
  2007年   207篇
  2006年   169篇
  2005年   177篇
  2004年   149篇
  2003年   90篇
  2002年   65篇
  2001年   18篇
  2000年   16篇
  1999年   11篇
  1998年   8篇
  1997年   7篇
  1996年   4篇
  1995年   3篇
  1994年   3篇
  1993年   4篇
  1992年   11篇
  1991年   5篇
  1990年   3篇
  1989年   4篇
  1988年   2篇
  1987年   4篇
  1986年   1篇
  1984年   5篇
  1983年   2篇
  1981年   1篇
  1980年   2篇
  1979年   3篇
  1978年   1篇
  1977年   1篇
  1975年   2篇
  1974年   1篇
  1972年   2篇
  1970年   1篇
排序方式: 共有2616条查询结果,搜索用时 31 毫秒
21.
The objective of this study was to investigate the prognostic significance of p53, and proliferative cell nuclear antigen (PCNA) in laryngeal squamous cell carcinoma (LSCC). Sixty pathologic specimens from the patients with LSCC were examined for the expression of the p53 and PCNA, with complete follow-up data. Sixty-three percent of the cases displayed nuclear p53 overexpression. There was a correlation between p53 overexpression and histological grades (p = 0.03), and localization site (p = 0.05). Median of PCNA index was 42.2 (range 5.9 to 85.2). There was no difference between the p53 overexpression group and the normal group in proliferative activity determined by PCNA (p = 0.73). In univariate analyses, localization site, grade, stage, invasion pattern, lymph node status, were significant factors in estimating disease free survival (DFS). Grade was the most important factor affecting recurrence (p = 0.002). In multivariate analyses, grade was the only significant predictor for DFS (p = 0.001). Grade (p = 0.001) and invasion pattern (p = 0.03) were found to be significant predictors of overall survival. In conclusion, the histological grade was the most reliable important prognostic factor. Further studies are necessary to facilitate understanding of the mechanisms of laryngeal carcinogenesis.  相似文献   
22.
The aim of this study was to investigate the presence of risk factors for predicting survival and to evaluate the efficacy of the radical surgery in patients with early stage cervical carcinoma. A total of 200 women who underwent radical hysterectomy and bilateral pelvic lymph node dissection for early stage cervical carcinoma were retrospectively analysed. We found that lymph node involvement (P <0.0015) and lymphovascular invasion (P <0.05) were the best prognostic factors for disease-free survival in our cases. The depth of cervical invasion, lymphovascular invasion and parametrial spread were closely related with lymph node involvement. Parametrial spread was shown in 38 patients (19%), assessed as stage Ia-IIa pre-operatively. Seventy-six stage Ib patients, at high-risk of recurrence, received adjuvant radiotherapy. Although there was some local tumour recurrence in the control group, adjuvant radiotherapy did not improve the overall survival in stage Ib patients. As a consequence, primary surgery would be definitive in estimating survival from histopathological evaluation. This study demonstrates that lymph node involvement and lymphovascular space infiltration were the best predictor factors for survival.  相似文献   
23.
24.
Background Acne vulgaris is a common disease affecting adolescents. There is not comprehensive data on acne prevalence in the Central Anatolia Region in particular. Etiology of acne is not clarified yet. Acne might be related to environmental factors. There is increasing evidence supporting acne and diet relationship. Objectives The aim of the study was to determine the acne prevalence in adolescents in the city of Eskisehir, located in the Central Anatolia, Turkey in addition to evaluate factors affecting acne and its relationship with dietary habits. Methods A cross‐sectional study was conducted on 2300 participants aged 13–18 years. The participants were asked to complete a questionnaire form consisting information about acne and a questionnaire form consisting information about dietary habits (The Adolescent Food Habits Checklist). In addition an objective evaluation of acne was determined. Results The mean age of students with acne was 15.10 ± 1.53. The current acne prevalence was 60.7%. Although 21% of the participants had severe acne (grade 3–4) and 25% developed sequelaes, only 11.5% of all participants consulted a doctor. The participants without acne had healthier dietary habits than participants with acne (P < 0.05). Frequent fat intake (OR = 1.39, 95% CI: 1.06–1.82), frequent sugar intake (OR = 1.30, 95% CI: 1.05–1.60), frequent eating sausages, burgers (OR = 1.24, 95% CI: 1.03–1.48), frequent eating pastries, cakes (OR = 1.20, 95% CI: 1.01–1.43) were associated with increased risk for acne. Conclusions Acne prevalence is high among adolescents in Eskisehir but the rate of consulting doctor is low. Increasing public awareness is critical for convincing adolescents to seek medical help earlier. Acne was related with dietary habits. Fat, sugar and fast food consumption is found to be positively correlated with acne prevalence.  相似文献   
25.
26.
27.
28.
29.
30.
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