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   38538篇
  免费   2958篇
  国内免费   65篇
耳鼻咽喉   622篇
儿科学   1238篇
妇产科学   865篇
基础医学   4848篇
口腔科学   513篇
临床医学   5446篇
内科学   6930篇
皮肤病学   579篇
神经病学   3353篇
特种医学   1200篇
外国民族医学   1篇
外科学   4703篇
综合类   976篇
一般理论   57篇
预防医学   4492篇
眼科学   731篇
药学   2307篇
中国医学   22篇
肿瘤学   2678篇
  2023年   302篇
  2022年   494篇
  2021年   1226篇
  2020年   734篇
  2019年   1138篇
  2018年   1274篇
  2017年   831篇
  2016年   914篇
  2015年   1056篇
  2014年   1404篇
  2013年   2208篇
  2012年   2826篇
  2011年   2805篇
  2010年   1421篇
  2009年   1246篇
  2008年   2147篇
  2007年   2292篇
  2006年   2104篇
  2005年   1974篇
  2004年   1984篇
  2003年   1717篇
  2002年   1622篇
  2001年   491篇
  2000年   507篇
  1999年   475篇
  1998年   352篇
  1997年   311篇
  1996年   286篇
  1995年   258篇
  1994年   220篇
  1993年   205篇
  1992年   332篇
  1991年   286篇
  1990年   298篇
  1989年   296篇
  1988年   294篇
  1987年   241篇
  1986年   315篇
  1985年   227篇
  1984年   222篇
  1983年   195篇
  1982年   161篇
  1981年   170篇
  1980年   162篇
  1979年   219篇
  1978年   141篇
  1977年   113篇
  1976年   119篇
  1975年   102篇
  1974年   105篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

3.

Background

There are well-established relationships between health and homelessness, and shelters can facilitate the transmission of diseases and contribute to their prevention. Adequate environmental health conditions and hygiene behaviors in homeless shelters are fundamental to the health of their clients, a marginalized population. We report the status of environmental health conditions and hygiene behaviors in homeless shelters and associated health outcomes; interventions to improve these conditions, behaviors, and outcomes; and obstacles to improvement.

Methods

PubMed, Web of Science, Scopus, and EBSCOhost were searched for peer-reviewed studies, and additional sources for grey literature. Studies were included if they reported primary data on one or more environmental health condition or hygiene behavior in homeless shelters.

Results

Twenty-eight studies were included in the review. Insufficient ventilation systems, unhygienic bedding, and overcrowding were the most documented environmental health and hygiene deficiencies in homeless shelters, and tuberculosis infections and skin diseases were the most documented associated health outcomes among clients. Studies frequently recommended or described implementation of behavioral and administrative controls, ventilation system improvements, and ultraviolet germicidal irradiation fixtures.

Discussion

Most studies addressed airborne transmission of tuberculosis and were conducted in high-income countries, revealing an imbalance in the literature. Insufficient resources and the transience of clients are barriers to improving hygiene behaviors and environmental conditions in homeless shelters. Further investment and research into ensuring adequate hygiene and environmental health in this setting can protect and promote the health and well-being of people experiencing homelessness.  相似文献   
4.
5.
ABSTRACT

Measuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised.  相似文献   
6.
ABSTRACT

This work collates data from the analysis of complex mixtures analysed in STRmix during routine no-suspect volume crime work. It interrogates the upload rate for these types of mixtures and which component of the profile has been able to be interpreted for upload. The number of profiles giving multiple uploads and the amount of replicate PCR analysis has been collated.  相似文献   
7.
8.
An essential piece of anesthesiologist training is attending resident feedback sessions. Yet, few attending anesthesiologists have formal teaching education and little time to acquire it. In this field experiment, attending physicians were randomly assigned to a control group or to receive 30 minutes of feedback training inspired by Implicit Person Theory (IPT). As such, IPT training encouraged physicians to praise process-oriented learning while discouraging performance-oriented mindsets. Attending physicians then observed residents participate in a human patient simulation (HPS) activity and provided residents with feedback. Content and statistical analyses revealed trained attending physicians praised learning goals and challenged performance goals more often than untrained physicians during feedback sessions. Thus, the training provides a rapid method of enhancing the quality of attending physicians’ training communication.  相似文献   
9.
Discrete choice experiments (DCEs) are frequently used in health economics to measure preferences for nonmarket goods. Best–worst discrete choice experiment (BWDCE) has been proposed as a variant of the traditional “pick the best” approach. BWDCE, where participants choose the best and worst options, is argued to generate more precise preference estimates because of the additional information collected. However, the validity of the approach relies on two necessary conditions: (a) best and worst decisions provide similar information about preferences and (b) asking individuals to answer more than one choice question per task does not reduce data quality. Whether these conditions hold in empirical applications remains under researched. This is the first study to compare participants' choices across three experimental conditions: (a) BEST choices only, (b) WORST choices only, and (c) BEST and WORST choices (BWDCE). We find responses to worst choices are noisier. Implied preferences from the best only and worst only choices are qualitatively different, leading to different WTP values. Responses to BWDCE tasks have lower consistency, and respondents are more likely to use simplifying decision heuristics. We urge caution in using BWDCE as an alternative to the traditional “pick the best” DCE.  相似文献   
10.
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security.  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