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   122729篇
  免费   10863篇
  国内免费   4348篇
耳鼻咽喉   942篇
儿科学   1848篇
妇产科学   2997篇
基础医学   14782篇
口腔科学   2963篇
临床医学   11232篇
内科学   13716篇
皮肤病学   1449篇
神经病学   9222篇
特种医学   5625篇
外国民族医学   17篇
外科学   10797篇
综合类   19439篇
现状与发展   11篇
一般理论   7篇
预防医学   12632篇
眼科学   2777篇
药学   13428篇
  154篇
中国医学   7918篇
肿瘤学   5984篇
  2024年   295篇
  2023年   1975篇
  2022年   2833篇
  2021年   5120篇
  2020年   4592篇
  2019年   4194篇
  2018年   4062篇
  2017年   4292篇
  2016年   4187篇
  2015年   4326篇
  2014年   7474篇
  2013年   8900篇
  2012年   7171篇
  2011年   8081篇
  2010年   6403篇
  2009年   6131篇
  2008年   6072篇
  2007年   6056篇
  2006年   5345篇
  2005年   4876篇
  2004年   4040篇
  2003年   3742篇
  2002年   2873篇
  2001年   2712篇
  2000年   2336篇
  1999年   2079篇
  1998年   1747篇
  1997年   1698篇
  1996年   1466篇
  1995年   1408篇
  1994年   1231篇
  1993年   1000篇
  1992年   941篇
  1991年   774篇
  1990年   784篇
  1989年   685篇
  1988年   514篇
  1987年   470篇
  1986年   488篇
  1985年   688篇
  1984年   610篇
  1983年   384篇
  1982年   471篇
  1981年   394篇
  1980年   402篇
  1979年   303篇
  1978年   240篇
  1977年   230篇
  1976年   206篇
  1975年   150篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
HIV risk in vulnerable groups such as itinerant male street labourers is often examined via a focus on individual determinants. This study provides a test of a modified Information-Motivation-Behavioral Skills (IMB) model to predict condom use behaviour among male street workers in urban Vietnam. In a cross-sectional survey using a social mapping technique, 450 male street labourers from 13 districts of Hanoi, Vietnam were recruited and interviewed. Collected data were first examined for completeness; structural equation modelling was then employed to test the model fit. Condoms were used inconsistently by many of these men, and usage varied in relation to a number of factors. A modified IMB model had a better fit than the original IMB model in predicting condom use behaviour. This modified model accounted for 49% of the variance, versus 10% by the original version. In the modified model, the influence of psychosocial factors was moderately high, whilst the influence of HIV prevention information, motivation and perceived behavioural skills was moderately low, explaining in part the limited level of condom use behaviour. This study provides insights into social factors that should be taken into account in public health planning to promote safer sexual behaviour among Asian male street labourers.  相似文献   
92.
93.

Introduction

The fast track / ultra-fast-track protocols are techniques used to optimise the patient care process and a quick recovery after cardiac surgery. They are one of the mainstays of efficient practice. With their use, the length of hospital and intensive care unit (ICU) stays are reduced, with a direct impact on costs and the quality of the health service.

Objective

To compare the length of stay in the ICU, length of hospital stay, and post-operative mortality in ultra-fast-track extubated (uFTE) patients and those with conventional extubation (CE) after cardiac surgery.

Methods

Longitudinal, analytical, retrospective study was conducted, with the period between the time of surgery and discharge being included as the study period.

Results

A total of 396 patients older than 18 years who required cardiac surgery were included, of whom 207 patients had (uFTE) and 189 had CE. Although the groups were not comparable due to the statistical differences found, when performing the multivariate adjustment, uFTE maintained its statistical independence and was associated with lower cardiovascular morbidity, such as myocardial ischaemia (95% CI: 0.37-0.86; P = .01) and lower post-surgical vasopressor requirement (95% CI: 0.18-0.49; P < .01). No significant differences were found in the length of hospital stay, ICU stay, or post-operative mortality in the ICU.

Conclusion

Implementing the uFTE strategy, decreases cardiovascular morbidity and vasopressor requirement. The change to uFTE should be accompanied by changes in models and practices in patient recovery to standardised protocols. This study shows that uFTE did not reduce the length of ICU stay, hospital stay, or mortality.  相似文献   
94.
95.
目的 探讨米索前列醇联合依沙吖啶在中晚期妊娠引产中的应用效果。方法 选取西安交通大学附属3201医院2012年1月—2017年12月收治的138例中晚期妊娠引产患者,按引产方式分为对照组、观察组,各69例。对照组使用乳酸依沙吖啶注射液进行引产,观察组在对照组的基础上联合使用米索前列醇进行引产。比较两组引产效果、胎儿娩出时间、阴道出血量及不良反应的发生情况。结果 观察组引产有效率是100%,显著高于对照组的91.75%(P<0.05)。观察组胎儿娩出时间<35 h的人数占比显著高于对照组(P<0.05)。观察组患者阴道出血量显著低于对照组(P<0.05),两组不良反应的发生率间差异不显著。结论 米索前列醇联合依沙吖啶在中晚期妊娠引产中的效果较好,可显著提高引产有效率、缩短胎儿娩出时间,值得临床应用。  相似文献   
96.
This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation.  相似文献   
97.
Accurately predicting the hepatic clearance of compounds using in vitro to in vivo extrapolation (IVIVE) is crucial within the pharmaceutical industry. However, several groups have recently highlighted the serious error in the process. Although empirical or regression-based scaling factors may be used to mitigate the common underprediction, they provide unsatisfying solutions because the reasoning behind the underlying error has yet to be determined. One previously noted trend was intrinsic clearance-dependent underprediction, highlighting the limitations of current in vitro systems. When applying these generated in vitro intrinsic clearance values during drug development and making first-in-human dose predictions for new chemical entities though, hepatic clearance is the parameter that must be estimated using a model of hepatic disposition, such as the well-stirred model. Here, we examine error across hepatic clearance ranges and find a similar hepatic clearance-dependent trend, with high clearance compounds not predicted to be so, demonstrating another gap in the field.  相似文献   
98.
99.
100.
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