收费全文 | 948330篇 |
免费 | 68602篇 |
国内免费 | 1373篇 |
耳鼻咽喉 | 13312篇 |
儿科学 | 24890篇 |
妇产科学 | 23549篇 |
基础医学 | 135450篇 |
口腔科学 | 28656篇 |
临床医学 | 82093篇 |
内科学 | 186533篇 |
皮肤病学 | 19530篇 |
神经病学 | 73945篇 |
特种医学 | 37581篇 |
外国民族医学 | 89篇 |
外科学 | 154697篇 |
综合类 | 18200篇 |
现状与发展 | 1篇 |
一般理论 | 240篇 |
预防医学 | 63120篇 |
眼科学 | 21980篇 |
药学 | 73718篇 |
3篇 | |
中国医学 | 2195篇 |
肿瘤学 | 58523篇 |
2018年 | 9232篇 |
2017年 | 7232篇 |
2016年 | 7990篇 |
2015年 | 9147篇 |
2014年 | 12348篇 |
2013年 | 18038篇 |
2012年 | 24840篇 |
2011年 | 25800篇 |
2010年 | 15263篇 |
2009年 | 14693篇 |
2008年 | 25301篇 |
2007年 | 26464篇 |
2006年 | 27196篇 |
2005年 | 26145篇 |
2004年 | 25244篇 |
2003年 | 24201篇 |
2002年 | 23800篇 |
2001年 | 55288篇 |
2000年 | 57102篇 |
1999年 | 47418篇 |
1998年 | 10949篇 |
1997年 | 9674篇 |
1996年 | 9758篇 |
1995年 | 9078篇 |
1994年 | 8411篇 |
1993年 | 7704篇 |
1992年 | 35825篇 |
1991年 | 34259篇 |
1990年 | 33079篇 |
1989年 | 32163篇 |
1988年 | 29319篇 |
1987年 | 28544篇 |
1986年 | 26579篇 |
1985年 | 25401篇 |
1984年 | 18035篇 |
1983年 | 15293篇 |
1982年 | 7923篇 |
1981年 | 6884篇 |
1979年 | 15977篇 |
1978年 | 10742篇 |
1977年 | 9205篇 |
1976年 | 8003篇 |
1975年 | 8761篇 |
1974年 | 10613篇 |
1973年 | 9988篇 |
1972年 | 9485篇 |
1971年 | 8971篇 |
1970年 | 8542篇 |
1969年 | 8033篇 |
1968年 | 7325篇 |
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Background
Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.Methods
We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A?]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.Results
Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A? (17 versus 7; P?=?.0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A?. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.Conclusions
In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits. 相似文献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