收费全文 | 935252篇 |
免费 | 68017篇 |
国内免费 | 1350篇 |
耳鼻咽喉 | 12974篇 |
儿科学 | 24534篇 |
妇产科学 | 23332篇 |
基础医学 | 133518篇 |
口腔科学 | 28306篇 |
临床医学 | 81077篇 |
内科学 | 184215篇 |
皮肤病学 | 19260篇 |
神经病学 | 72667篇 |
特种医学 | 36938篇 |
外国民族医学 | 79篇 |
外科学 | 152754篇 |
综合类 | 18110篇 |
现状与发展 | 1篇 |
一般理论 | 235篇 |
预防医学 | 62209篇 |
眼科学 | 21648篇 |
药学 | 72824篇 |
3篇 | |
中国医学 | 2163篇 |
肿瘤学 | 57772篇 |
2018年 | 9033篇 |
2017年 | 7080篇 |
2016年 | 7816篇 |
2015年 | 8929篇 |
2014年 | 12085篇 |
2013年 | 17667篇 |
2012年 | 24322篇 |
2011年 | 25301篇 |
2010年 | 14949篇 |
2009年 | 14406篇 |
2008年 | 24846篇 |
2007年 | 25969篇 |
2006年 | 26748篇 |
2005年 | 25720篇 |
2004年 | 24834篇 |
2003年 | 23884篇 |
2002年 | 23381篇 |
2001年 | 54829篇 |
2000年 | 56648篇 |
1999年 | 47044篇 |
1998年 | 10807篇 |
1997年 | 9512篇 |
1996年 | 9629篇 |
1995年 | 8981篇 |
1994年 | 8317篇 |
1993年 | 7634篇 |
1992年 | 35556篇 |
1991年 | 33979篇 |
1990年 | 32780篇 |
1989年 | 31930篇 |
1988年 | 29057篇 |
1987年 | 28328篇 |
1986年 | 26341篇 |
1985年 | 25201篇 |
1984年 | 17866篇 |
1983年 | 15180篇 |
1982年 | 7821篇 |
1981年 | 6798篇 |
1979年 | 15818篇 |
1978年 | 10641篇 |
1977年 | 9091篇 |
1976年 | 7899篇 |
1975年 | 8665篇 |
1974年 | 10497篇 |
1973年 | 9888篇 |
1972年 | 9390篇 |
1971年 | 8880篇 |
1970年 | 8450篇 |
1969年 | 7949篇 |
1968年 | 7219篇 |
Background
Payers frequently rely on budget impact model (BIM) results to help determine drug coverage policy and its effect on their bottom line. It is unclear whether BIMs typically overestimate or underestimate real-world budget impact.Objective
We examined how different modeling assumptions influenced the results of 6 BIMs from the Institute for Clinical and Economic Review (ICER).Study Design
Retrospective analysis of pharmaceutical sales data.Methods
From ICER reports issued before 2016, we collected estimates of 3 BIM outputs: aggregate therapy cost (ie, cost to treat the patient population with a particular therapy), therapy uptake, and price. We compared these against real-world estimates that we generated using drug sales data. We considered 2 classes of BIM estimates: those forecasting future uptake of new agents, which assumed “unmanaged uptake,” and those describing the contemporaneous market state (ie, estimates of current, managed uptake and budget impact for compounds already on the market).Results
Differences between ICER's estimates and our own were largest for forecasted studies. Here, ICER's uptake estimates exceeded real-world estimates by factors ranging from 7.4 (sacubitril/valsartan) to 54 (hepatitis C treatments). The “unmanaged uptake” assumption (removed from ICER's approach in 2017) yields large deviations between BIM estimates and real-world consumption. Nevertheless, in some cases, ICER's BIMs that relied on current market estimates also deviated substantially from real-world sales data.Conclusions
This study highlights challenges with forecasting budget impact. In particular, assumptions about uptake and data source selection can greatly influence the accuracy of results. 相似文献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