全文获取类型
收费全文 | 10530篇 |
免费 | 984篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 99篇 |
儿科学 | 263篇 |
妇产科学 | 377篇 |
基础医学 | 1627篇 |
口腔科学 | 145篇 |
临床医学 | 817篇 |
内科学 | 2075篇 |
皮肤病学 | 495篇 |
神经病学 | 1055篇 |
特种医学 | 358篇 |
外科学 | 1376篇 |
综合类 | 73篇 |
一般理论 | 2篇 |
预防医学 | 1102篇 |
眼科学 | 100篇 |
药学 | 851篇 |
中国医学 | 38篇 |
肿瘤学 | 678篇 |
出版年
2023年 | 82篇 |
2022年 | 73篇 |
2021年 | 169篇 |
2020年 | 141篇 |
2019年 | 198篇 |
2018年 | 216篇 |
2017年 | 194篇 |
2016年 | 203篇 |
2015年 | 229篇 |
2014年 | 247篇 |
2013年 | 450篇 |
2012年 | 559篇 |
2011年 | 541篇 |
2010年 | 328篇 |
2009年 | 305篇 |
2008年 | 498篇 |
2007年 | 425篇 |
2006年 | 480篇 |
2005年 | 453篇 |
2004年 | 454篇 |
2003年 | 388篇 |
2002年 | 343篇 |
2001年 | 311篇 |
2000年 | 329篇 |
1999年 | 302篇 |
1998年 | 134篇 |
1997年 | 94篇 |
1996年 | 106篇 |
1995年 | 112篇 |
1994年 | 96篇 |
1993年 | 84篇 |
1992年 | 209篇 |
1991年 | 220篇 |
1990年 | 203篇 |
1989年 | 225篇 |
1988年 | 205篇 |
1987年 | 192篇 |
1986年 | 165篇 |
1985年 | 174篇 |
1984年 | 142篇 |
1983年 | 107篇 |
1982年 | 90篇 |
1981年 | 70篇 |
1979年 | 107篇 |
1978年 | 76篇 |
1977年 | 83篇 |
1976年 | 63篇 |
1974年 | 67篇 |
1973年 | 69篇 |
1972年 | 63篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
131.
Eighth young adult male volunteers with a basic (alimentary) plasma boric acid concentration of <0.10–0.46 mg/l were given a single dose of boric acid (562–611 mg) by 20 min IV infusion. The plasma concentration curves, followed for 3 days, best fitted a three-compartment open model, although two subjects had to be left out due to inconstant basal plasma concentration values or failure to fit to the three-compartment model. The 120 h urinary excretion was 98.7±9.1% of dose, Cltot 54.6±8.0 ml/min/1.73 m2, t1/2 21.0±4.9 h and distribution volumes V1, V2, and V3: 0.251±0.099, 0.456±0.067 and 0.340±0.128 l/kg. 相似文献
132.
133.
Andersen Patrick Mizdrak Anja Wilson Nick Davies Anna Bablani Laxman Blakely Tony 《Population health metrics》2022,20(1):1-12
The mortality pattern from birth to age five is known to vary by underlying cause of mortality, which has been documented in multiple instances. Many countries without high functioning vital registration systems could benefit from estimates of age- and cause-specific mortality to inform health programming, however, to date the causes of under-five death have only been described for broad age categories such as for neonates (0–27 days), infants (0–11 months), and children age 12–59 months. We adapt the log quadratic model to mortality patterns for children under five to all-cause child mortality and then to age- and cause-specific mortality (U5ACSM). We apply these methods to empirical sample registration system mortality data in China from 1996 to 2015. Based on these empirical data, we simulate probabilities of mortality in the case when the true relationships between age and mortality by cause are known. We estimate U5ACSM within 0.1–0.7 deaths per 1000 livebirths in hold out strata for life tables constructed from the China sample registration system, representing considerable improvement compared to an error of 1.2 per 1000 livebirths using a standard approach. This improved prediction error for U5ACSM is consistently demonstrated for all-cause as well as pneumonia- and injury-specific mortality. We also consistently identified cause-specific mortality patterns in simulated mortality scenarios. The log quadratic model is a significant improvement over the standard approach for deriving U5ACSM based on both simulation and empirical results. 相似文献
134.
135.
Per Kragh Andersen Maja Pohar Perme Hans C. van Houwelingen Richard J. Cook Pierre Joly Torben Martinussen Jeremy M. G. Taylor Michal Abrahamowicz Terry M. Therneau 《Statistics in medicine》2021,40(1):185-211
This paper provides guidance for researchers with some mathematical background on the conduct of time‐to‐event analysis in observational studies based on intensity (hazard) models. Discussions of basic concepts like time axis, event definition and censoring are given. Hazard models are introduced, with special emphasis on the Cox proportional hazards regression model. We provide check lists that may be useful both when fitting the model and assessing its goodness of fit and when interpreting the results. Special attention is paid to how to avoid problems with immortal time bias by introducing time‐dependent covariates. We discuss prediction based on hazard models and difficulties when attempting to draw proper causal conclusions from such models. Finally, we present a series of examples where the methods and check lists are exemplified. Computational details and implementation using the freely available R software are documented in Supplementary Material. The paper was prepared as part of the STRATOS initiative. 相似文献
136.
Lars L Andersen Sannie V Thorsen Mona Larsen Emil Sundstrup Ccile RL Boot Reiner Rugulies 《Scandinavian journal of work, environment & health》2021,47(1):15
Objectives:The demographic changes in Europe underline the need for an extension of working lives. This study investigates the importance of physical work demands and psychosocial work factors for working beyond the state pension age (65 years).Methods:We combined data from three cohorts of the general working population in Denmark (DWECS 2005 and 2010, and DANES 2008), where actively employed workers aged 55–59 years replied to questionnaires about work environment and were followed until the age of 66 years in the Danish AMRun register of paid employment. Using logistic regression analyses, we calculated prevalence ratios (PR) and 95% confidence intervals (CI) for the association between physical and psychosocial work factors and working beyond state pension age, adjusted for age, sex, cohort, cohabiting, sector, income, vocational education, working hours, lifestyle, and previous sickness absence.Results:Of the 2884 workers aged 55–59 years, 1023 (35.5%) worked beyond the state pension age. Higher physical work demands was associated with a lower likelihood (PR 0.69, 95% CI 0.58–0.82) and a good psychosocial work environment was associated with higher likelihood (average of 7 items: PR 1.81, 95% CI 1.49–2.20) of working beyond state pension age. Stratified analyses did not change the overall pattern, ie, a good overall psychosocial work environment – as well as several specific psychosocial factors – increased the likelihood of working beyond state pension age, both for those with physically active and seated work.Conclusion:While high physical work demands was a barrier, a good psychosocial work environment seems to facilitate working beyond state pension age, also for those with physically active work. 相似文献
137.
138.
139.
Counselors' reports of their use of self-disclosure with clients 总被引:1,自引:0,他引:1
Ninety-six counselors indicated the frequency of their use of 11 types of self-disclosure, which varied in intimacy from incidental information (age, race) to personal weaknesses. Positive emotional responses to clients were used most frequently, and opinions/attitudes were used least frequently. A factor analysis showed three factors to describe the data best. Factor 1 was represented by information related to the personal identify and experiences of the therapist. Factor 2 involved the emotional responses of the therapist to the client. Factor 3 was principally the disclosure of professional experiences and identity. Implications are considered. 相似文献
140.