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   1420篇
  免费   241篇
  国内免费   17篇
耳鼻咽喉   42篇
儿科学   12篇
妇产科学   54篇
基础医学   37篇
口腔科学   11篇
临床医学   59篇
内科学   137篇
皮肤病学   6篇
神经病学   30篇
特种医学   40篇
外国民族医学   8篇
外科学   228篇
综合类   136篇
预防医学   45篇
眼科学   4篇
药学   55篇
中国医学   25篇
肿瘤学   749篇
  2024年   5篇
  2023年   19篇
  2022年   27篇
  2021年   91篇
  2020年   62篇
  2019年   76篇
  2018年   48篇
  2017年   72篇
  2016年   106篇
  2015年   101篇
  2014年   133篇
  2013年   153篇
  2012年   96篇
  2011年   123篇
  2010年   86篇
  2009年   74篇
  2008年   73篇
  2007年   62篇
  2006年   76篇
  2005年   43篇
  2004年   30篇
  2003年   25篇
  2002年   17篇
  2001年   16篇
  2000年   8篇
  1999年   4篇
  1998年   16篇
  1997年   4篇
  1996年   5篇
  1995年   3篇
  1994年   3篇
  1993年   2篇
  1992年   5篇
  1991年   1篇
  1987年   3篇
  1986年   4篇
  1985年   2篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
排序方式: 共有1678条查询结果,搜索用时 625 毫秒
41.
42.
43.
44.
45.
46.
PURPOSE: The aim of this study was to evaluate the efficacy of preoperative radiation therapy for resectable rectal adenocarcinoma (T3-T4) when delivered in combination with chemotherapy (oral tegafur-uracil modulated with leucovorin). METHODS: Thirty-eight patients (23 males; mean age, 62 years.) with histologically proven rectal adenocarcinoma with primary tumor clinical classification T3-T4 (resectable) and N0 or N1-N2, according to TNM staging system, took part in the present clinical trial. After tumor and metastasis resectability confirmation, radiation therapy was administered by delivering a dose of 45 Gy in 25 fractions for 5 weeks. Chemotherapy treatment was initiated on the same day as radiotherapy and consisted of intravenous infusion of 6S-steroisomer of leucovorin 250 mg/m2/day in 2 hours on Day 1, followed by oral 350 or 300 mg/m2/day of tegafur (a 5-fluorouracil prodrug) plus uracil on Days 1 to 14 divided into 2 daily doses, and oral 6S-steroisomer of leucovorin 7.5 mg/12 hours on Days 2 to 14, with a total of 102 courses of neoadjuvant chemotherapy (i.e., mean of 2.7 courses per patient). Six additional courses of tegafur-uracil were given postoperatively to all 38 patients but 1 who refused. RESULTS: As a result of preoperative chemoradiation treatment, 4 (10.5 percent) complete responses, 20 (52.6 percent) partial responses, and 14 (36.8 percent) patients with disease stabilization were observed. No patients had preoperative disease progression. Histologically proven downstaging was observed in 23 (60 percent) patients. On initial evaluation, only 39 percent of patients were considered as being good candidates for sphincter-preserving surgery; however, on preoperative chemoradiation completion this figure increased up to 60 percent. For the 23 patients eventually undergoing sphincter-preserving surgery, postoperative sphincter function assessment showed excellent function in 15 (65 percent) patients, good in 5 (22 percent), fair in 2 (9 percent), and poor in 1(4 percent). With a median follow-up of 37 (range, 10–62) months, local failure was found in 3 (8 percent) patients and distant failure in 2 (5 percent). Three-year actuarial disease-free survival and 3-year overall survival rates were 83 and 90 percent, respectively. Local control rate was 92 percent. Toxicity and postoperative complication rates were reasonable. CONCLUSIONS: Our neoadjuvant radiation therapy protocol is efficient for the preoperative treatment of resectable rectal adenocarcinoma when combined with chemotherapy (oral tegafur-uracil modulated with leucovorin). However, this protocol needs to be tested in a phase-III clinical trial with a larger sample size.  相似文献   
47.
48.
Background: Though alcohol and tobacco are the most commonly used substances among adolescents, little is known about the patterning of early adolescent substance use in Association of South-East Asian Nations (ASEAN) member states. Objectives: This study examined past month patterns of substances use and its gender difference among adolescents. Methods: Cross-sectional samples among adolescents aged 13–16?years who completed the Global School-based Student Health Survey (GSHS) from eight ASEAN countries were included in the analysis (n?=?40,212). Results: Prevalence of past month any tobacco use was relatively high in Brunei, Indonesia, Malaysia, Thailand, and the Philippines (11–15%), but prevalence of dual cigarette and other forms of tobacco use was about 2–5% in the five countries. Past month alcohol consumption prevalence was also high in Thailand, Viet Nam, and the Philippines (16–24%), compared to the rest countries (1.4–8.2%). Moreover, prevalence of the concurrent alcohol and tobacco use was higher in Thailand and the Philippines (7 and 10%, respectively), particularly in boys (13 and 15%, respectively). Conclusions/importance: Almost 30–40% of the boys and 10–20% of girls in Malaysia, Philippines, Thailand, and Viet Nam are engaged in at least one of the two risk behaviors, and the concurrent alcohol and tobacco use was also relatively high among boys in those countries (5–15%). This study may provide some valuable insights on alcohol and tobacco policy in the region and requires to begin prevention and treatment programs in ASEAN member states.  相似文献   
49.
50.
Introduction: In this study we examined oxidative stress and skeletal muscle damage resulting from acute strength, aerobic, or concurrent exercise in rats. Methods: The animals were divided into control (C), strength (SE), aerobic (AE), and combined (CE) exercise groups. They were euthanized at 3 different time‐points (6, 24, and 48 h) after acute exercise. Results: SE exercise rats had increased dichlorofluorescein oxidation at 6 h post‐exercise and decreased superoxide dismutase activity at all time‐points. Glutathione peroxidase activity and sulfhydryl levels were increased in the AE group at 48 h post‐exercise. Serum lactate dehydrogenase activity was increased in the SE and CE groups at 24 h and in the AE group at 48 h. Echo intensity was elevated at 24 h for all groups. Conclusions: Forty‐eight hours was sufficient for complete recovery from oxidative stress and muscle damage in the SE and CE groups, but not in the AE group. Muscle Nerve 50 : 79–86, 2014  相似文献   
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