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   11775篇
  免费   950篇
  国内免费   43篇
耳鼻咽喉   105篇
儿科学   445篇
妇产科学   320篇
基础医学   1457篇
口腔科学   108篇
临床医学   1514篇
内科学   2209篇
皮肤病学   168篇
神经病学   1305篇
特种医学   282篇
外科学   1270篇
综合类   113篇
一般理论   18篇
预防医学   1721篇
眼科学   150篇
药学   881篇
中国医学   8篇
肿瘤学   694篇
  2024年   19篇
  2023年   154篇
  2022年   209篇
  2021年   420篇
  2020年   303篇
  2019年   443篇
  2018年   470篇
  2017年   384篇
  2016年   421篇
  2015年   404篇
  2014年   548篇
  2013年   723篇
  2012年   1040篇
  2011年   1043篇
  2010年   566篇
  2009年   435篇
  2008年   761篇
  2007年   773篇
  2006年   669篇
  2005年   592篇
  2004年   540篇
  2003年   480篇
  2002年   440篇
  2001年   93篇
  2000年   66篇
  1999年   79篇
  1998年   78篇
  1997年   52篇
  1996年   59篇
  1995年   42篇
  1994年   45篇
  1993年   47篇
  1992年   41篇
  1991年   38篇
  1990年   41篇
  1989年   32篇
  1988年   27篇
  1987年   20篇
  1986年   24篇
  1985年   25篇
  1984年   28篇
  1983年   12篇
  1982年   9篇
  1981年   10篇
  1980年   5篇
  1979年   6篇
  1978年   6篇
  1977年   5篇
  1975年   6篇
  1974年   5篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
1.
2.
3.
4.
PurposeRegional nodal irradiation (RNI) improved disease-free survival by 3% to 5% in 2 large randomized trials, but this small absolute advantage relies on accurate contouring and dose delivery. We audited our network to determine compliance on regional nodal coverage, contouring, and dosimetric parameters with respect to accepted guidelines.Methods and MaterialsIn our network, we have established a clinical pathway for patients with node-positive breast cancer that guides indications for RNI and dosimetric goals. We reviewed records of 183 patients with nodal macrometastases after upfront surgery or involved nodes of any size after neoadjuvant chemotherapy. Radiation treatment plans were examined to determine lymph node volumes treated, whether nodes were contoured, quality of nodal contours, and whether target coverage and normal organ dosimetric constraints were met when RNI was delivered.ResultsDespite the presence of macrometastases on sentinel lymph node biopsy, no lymph nodes were treated in 2.2% (4 of 183). Of 179 patients who received nodal irradiation, 18 received radiation to axillary levels 1 and 2 only, and 161 patients received RNI. Overall, regional nodes were not treated despite strong indications in 7.6% (14 of 183). Treated nodes were not contoured for 2.2% (4 of 179), and lymph node contours were unacceptable in 15.4% (27 of 175). Of patients receiving RNI, 14.9% (24 of 161) did not have adequate nodal target volume coverage, mean heart dose was >4 Gy for 3.1% (5 of 161), and lung V20 Gy was >35% for 8.7% (14 of 161).ConclusionsAdherence to indications for regional nodal treatment was high, but nodes were either not contoured or had unacceptable contour quality in 18% of plans, and coverage was inadequate in 15%. Because the small disease-free survival advantage seen in trials may be decreased with these deviations, routine clinical practice requires detailed peer review to fully translate results of clinical trials.  相似文献   
5.
BACKGROUND: Penetrating injuries of the perineum are rare but very dangerous. Since the genitourinary and colorectal organs may be injured, how to evaluate surgical management of the injury is very important.METHODS: The present report presents a case of penetrating injury of the perineum by a wooden stick when the patient fell on the upright wooden stick from a tree. The three feet long stick entered the perineal region just left lateral to the anal opening. Upon reaching the thoracic cavity, it broke and only a foot stick was left in the subcutaneous plane. These injuries are potentially serious with risk of damage to multiple organs. Exploratory laprotomy was done, and bladder injury was repaired. The entry wound and the track of stick was thoroughly washed and allowed for secondary intention healing.RESULTS: The post operative period was uneventful and the patient recovered fully.CONCLUSION: Meticulous evaluation and surgical management of perineal injuries are the key to prevent devastating complications.  相似文献   
6.

Objectives

The current study investigated the effects of two exercise interventions on cognitive function amongst breast cancer survivors.

Design

Pilot randomised-controlled trial.

Methods

Seventeen female cancer survivors (mean: 62.9 ± 7.8 years) were randomised into three groups: high-intensity interval training (HIIT, n = 6); moderate-intensity continuous training (MOD, n = 5); or wait-list control (CON, n = 6). The HIIT and MOD groups exercised on a cycle ergometer 3 days/week for 12-weeks. Primary outcomes were cognitive function assessments utilising CogState. Secondary outcomes were resting middle cerebral artery blood flow velocity, cerebrovascular reactivity and aerobic fitness (VO2peak). Data were analysed with General Linear Mixed Models and Cohen’s d effect sizes were calculated.

Results

All 17 participants who were randomised were available for follow-up analysis and adherence was similar for HIIT and MOD (78.7 ± 13.2% vs 79.4 ± 12.0%; p = 0.93). Although there were no significant differences in the cognitive and cerebrovascular outcomes, HIIT produced moderate to large positive effects in comparison to MOD and CON for outcomes including episodic memory, working memory, executive function, cerebral blood flow and cerebrovascular reactivity. HIIT significantly increased VO2peak by 19.3% (d = 1.28) and MOD had a non-significant 5.6% (d = 0.72) increase, compared to CON which had a 2.6% decrease.

Conclusions

This study provides preliminary evidence that HIIT may be an effective exercise intervention to improve cognitive performance, cerebrovascular function and aerobic fitness in breast cancer survivors. Considering the sample size is small, these results should be confirmed through larger clinical trials.  相似文献   
7.
8.
9.
10.

Background  

Self-report recall questionnaires are commonly used to measure physical activity, energy expenditure and time use in children and adolescents. However, self-report questionnaires show low to moderate validity, mainly due to inaccuracies in recalling activity in terms of duration and intensity. Aside from recall errors, inaccuracies in estimating energy expenditure from self-report questionnaires are compounded by a lack of data on the energy cost of everyday activities in children and adolescents. This article describes the development of the Multimedia Activity Recall for Children and Adolescents (MARCA), a computer-delivered use-of-time instrument designed to address both the limitations of self-report recall questionnaires in children, and the lack of energy cost data in children.  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