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   983216篇
  免费   70635篇
  国内免费   1935篇
耳鼻咽喉   13901篇
儿科学   24932篇
妇产科学   24009篇
基础医学   142066篇
口腔科学   29539篇
临床医学   85123篇
内科学   193157篇
皮肤病学   21036篇
神经病学   75883篇
特种医学   39618篇
外国民族医学   79篇
外科学   158998篇
综合类   18240篇
现状与发展   2篇
一般理论   250篇
预防医学   64288篇
眼科学   22479篇
药学   77311篇
  3篇
中国医学   2776篇
肿瘤学   62096篇
  2021年   7610篇
  2018年   10569篇
  2017年   8216篇
  2016年   9461篇
  2015年   11352篇
  2014年   14963篇
  2013年   20866篇
  2012年   29248篇
  2011年   29712篇
  2010年   17526篇
  2009年   16564篇
  2008年   27862篇
  2007年   28666篇
  2006年   28996篇
  2005年   27671篇
  2004年   26494篇
  2003年   25224篇
  2002年   24511篇
  2001年   55808篇
  2000年   57548篇
  1999年   47662篇
  1998年   11056篇
  1997年   9699篇
  1996年   9776篇
  1995年   9078篇
  1994年   8403篇
  1993年   7710篇
  1992年   35751篇
  1991年   34161篇
  1990年   32955篇
  1989年   32079篇
  1988年   29201篇
  1987年   28450篇
  1986年   26432篇
  1985年   25267篇
  1984年   17919篇
  1983年   15232篇
  1982年   7838篇
  1979年   15849篇
  1978年   10659篇
  1977年   9087篇
  1976年   7911篇
  1975年   8673篇
  1974年   10519篇
  1973年   9900篇
  1972年   9404篇
  1971年   8887篇
  1970年   8473篇
  1969年   7941篇
  1968年   7228篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Shaving and other modes of epilation can cause undue anxiety, pain, or skin irritation in children. Here, we present hair trimming as a safe, painless, and cost‐effective alternative for patients with unwanted hair which may be performed indefinitely or until the child is old enough to direct management. In select cases, removing unwanted hair using this technique may facilitate dermatologic surveillance.  相似文献   
102.

Objectives

To investigate whether functional overreaching affects locomotor system behaviour when running at fixed relative intensities and if any effects were associated with changes in running performance.

Design

Prospective intervention study.

Methods

Ten trained male runners completed three training blocks in a fixed order. Training consisted of one week of light training (baseline), two weeks of heavy training designed to induce functional overreaching, and ten days of light taper training designed to allow athletes to recover from, and adapt to, the heavy training. Locomotor behaviour, 5-km time trial performance, and subjective reports of training status (Daily Analysis of Life Demands for Athletes (DALDA) questionnaire) were assessed at the completion of each training block. Locomotor behaviour was assessed using detrended fluctuation analysis of stride intervals during running at speeds corresponding to 65% and 85% of maximum heart rate (HRmax) at baseline.

Results

Time trial performance (effect size ±95% confidence interval (ES): 0.16 ± 0.06; p < 0.001), locomotor behaviour at 65% HRmax (ES: ?1.12 ± 0.95; p = 0.026), and DALDA (ES: 2.55 ± 0.80; p < 0.001) were all detrimentally affected by the heavy training. Time trial performance improved relative to baseline after the taper (ES: ?0.16 ± 0.10; p = 0.003) but locomotor behaviour at 65% HRmax (ES: ?1.18 ± 1.17; p = 0.048) and DALDA (ES: 0.92 ± 0.90; p = 0.045) remained impaired.

Conclusions

Locomotor behaviour during running at 65% HRmax was impaired by functional overreaching and remained impaired after a 10-day taper, despite improved running performance. Locomotor changes may increase injury risk and should be considered within athlete monitoring programs independently of performance changes.  相似文献   
103.
Bulletin of Experimental Biology and Medicine - Fast neutron therapy, which previously has demonstrated effective results, but along with a large number of complications, can again be considered a...  相似文献   
104.
105.
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism.  相似文献   
106.
Purpose of the study: the aim of this study was to synthesize PFC fNIRS outcomes on the effects of cognitive tasks compared to resting/baseline tasks in healthy adults from studies utilizing a pre/post design.

Material and methods: original research studies were searched from seven databases (MEDLINE, EMBASE, CENTRAL, CINAHL, SCOPUS, PEDro and PubMed). Subsequently, two independent reviewers screened the titles and abstracts followed by full-text reviews to assess the studies' eligibility.

Results: eleven studies met the inclusion criteria and had data abstracted and quality assessed. Methodology varied considerably and yet cognitive tasks resulted in the ΔO2Hb increasing in 8 of the 11 and ΔHHb decreasing in 8 of 8 studies that reported this outcome. The cognitive tasks from 10 of the 11 studies were classified as “Working Memory” and “Verbal Fluency Tasks”.

Conclusions: although, the data comparison was challenging provided the heterogeneity in methodology, the results across studies were similar.  相似文献   

107.
108.
109.

Background

The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.

Objectives

The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.

Methods

PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.

Results

Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).

Conclusions

In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550)  相似文献   
110.
Lung - Diaphragmatic paralysis (DP) is an important cause of dyspnea with many underlying etiologies; however, frequently no cause is identified despite extensive investigation. We hypothesized...  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