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   61826篇
  免费   4195篇
  国内免费   173篇
耳鼻咽喉   545篇
儿科学   1892篇
妇产科学   1537篇
基础医学   8056篇
口腔科学   972篇
临床医学   8490篇
内科学   11601篇
皮肤病学   1294篇
神经病学   5731篇
特种医学   1607篇
外国民族医学   1篇
外科学   7068篇
综合类   810篇
一般理论   115篇
预防医学   6751篇
眼科学   1313篇
药学   3867篇
中国医学   86篇
肿瘤学   4458篇
  2023年   288篇
  2022年   553篇
  2021年   1117篇
  2020年   679篇
  2019年   1117篇
  2018年   1315篇
  2017年   980篇
  2016年   1036篇
  2015年   1272篇
  2014年   1861篇
  2013年   2794篇
  2012年   4154篇
  2011年   4348篇
  2010年   2411篇
  2009年   2079篇
  2008年   4039篇
  2007年   4087篇
  2006年   4090篇
  2005年   3991篇
  2004年   3858篇
  2003年   3649篇
  2002年   3489篇
  2001年   626篇
  2000年   465篇
  1999年   647篇
  1998年   744篇
  1997年   678篇
  1996年   611篇
  1995年   547篇
  1994年   504篇
  1993年   487篇
  1992年   447篇
  1991年   386篇
  1990年   362篇
  1989年   356篇
  1988年   310篇
  1987年   304篇
  1986年   278篇
  1985年   330篇
  1984年   370篇
  1983年   372篇
  1982年   438篇
  1981年   421篇
  1980年   371篇
  1979年   261篇
  1978年   249篇
  1977年   249篇
  1976年   175篇
  1975年   185篇
  1974年   210篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Introduction: The landscape of poly (ADP-ribose) polymerase (PARP) inhibition in ovarian cancer is rapidly evolving and becoming increasingly complex. Ovarian cancer is leading therapeutic innovation by providing the proof of concept for DNA repair as a target. Three different PARP inhibitors have now received approvals in the US and Europe in different indications. Subtle but crucial differences can be found among the licensed indications for each PARP inhibitor in terms of histology, type of BRCA mutation (germline and/or somatic), number of prior lines of chemotherapy and whether the indication is in the treatment or maintenance settings.

Areas covered: We review the latest clinical data regarding the PARP inhibitor rucaparib in ovarian cancer, provide an update on the evolving landscape of PARP inhibition in ovarian cancer, and summarize avenues of ongoing and future research.

Expert opinion: All eligible patients should be offered a PARP inhibitor. SOLO1 trial results demonstrated an unprecedented benefit maintenance with PARP inhibitors in first line. Results from trials evaluating PARP inhibitors as maintenance in first line regardless of BRCA status and from trials evaluating combinatorial strategies are eagerly awaited.  相似文献   

3.
Henna, derived from a combination of natural leaves and coloring additives, is a common decorative dye traditionally used in many Islamic religious celebrations. Para‐phenylenediamine (PPD), a major component of black henna tattoo, is a strong sensitizer and common allergen. We report a case of severe connubial allergic contact dermatitis after black henna heterotransfer in a girl.  相似文献   
4.
5.
6.

Background

The purpose of this study was to compare the outcomes of trauma patients who were injured in a motor vehicle crash and tested positive for alcohol upon hospital arrival versus those who tested negative.

Methods

Study data came from the US National Trauma Data Bank (2007–2010). Any blood alcohol concentration (BAC) found at or above the legal limit (≥0.08?g/dL) was considered “alcohol positive”, and if no alcohol was identified through testing, the patient was considered “alcohol negative”. Patients’ demographics including age >?=?14, race, gender, drug test results, systolic blood pressure, heart rate, injury severity score (ISS), and Glasgow Coma Scale (GCS) were included in the study. Propensity score and exact pair matching were performed between the groups using baseline characteristics.

Results

From a total of 88,794 patients, 30.9% tested positive and 69.1% tested negative for alcohol. There were significant differences found between the groups regarding age, gender, race, and GCS (all p?<?0.001) as well as a significantly higher in-hospital mortality rate (3.5% vs. 2.7%, p?<?0.001) and median time to patient expiration (4 vs. 3 days, p?<?0.001) in the alcohol negative group. After running both matching scenarios, there was no evidence of a significant difference seen in the rates of in-hospital mortality or the median time to patient expiration between the alcohol groups in either matched comparison.

Conclusion

Patients who tested positive for alcohol following a traumatic motor vehicle crash showed no significant increase in in-hospital mortality or time to expiration when compared to propensity score and exact matched patients who tested negative for alcohol.  相似文献   
7.
Tuberculosis (TB) remains one of a major health problem worldwide. Tuberculosis vaccine research has made an extraordinary progress over the past few years. However, there is still no replacement for the Bacillus Calmette‐Guérin vaccine, the only TB vaccine licensed for human use. Therefore, the discovery and development of new TB vaccines remains a priority. This article discusses current strategies used to diversify TB vaccines and includes discussion of the status of efforts to improve protection against Mycobacterium tuberculosis (M tb) infection or TB disease by developing new and safe TB vaccines. This article also highlights the current research efforts in immune‐enhancing approaches to improve vaccination efficacy. The development of more effective TB vaccines might have significant impact on global TB control.  相似文献   
8.
ObjectiveTo evaluate changes in insurance status among emergency department (ED) patients presenting in the two years immediately before and after full implementation of the Affordable Care Act (ACA).MethodsWe evaluated National Hospital Ambulatory Medical Care Survey (NHAMCS) Emergency Department public use data for 2012–2015, categorizing patients as having any insurance (private; Medicare; Medicaid; workers' compensation) or no insurance. We compared the pre- and post-ACA frequency of insurance coverage—overall and within the older (≥65), working-age (18–64) and pediatric (<18) subpopulations—using unadjusted odds ratios with 95% confidence intervals. We also conducted a difference-in-differences analysis comparing the change in insurance coverage among working-age patients with that observed for older Medicare-eligible patients, while controlling for sex, race and underlying temporal trends.ResultsOverall, the proportion of ED patients with any insurance did not significantly change from 2012 to 2013 to 2014–2015 (74.2% vs 77.7%) but the proportion of working-age adult patients with at least one form of insurance increased significantly, from 66.0% to 71.8% (OR 1.31, CI: 1.13–1.52). The difference-in-differences analysis confirmed the change in insurance coverage among working-age adults was greater than that seen in the reference population of Medicare-eligible adults (AOR 1.70, CI: 1.29–2.23). The increase was almost entirely attributable to increased Medicaid coverage.ConclusionIn the first two years following full implementation of the ACA, there was a significant increase in the proportion of working-age adult ED patients who had at least one form of health insurance. The increase appeared primarily associated with expansion of Medicaid.  相似文献   
9.
10.
In May 2017, the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee hosted a workshop to discuss whether mode of action (MOA) investigation is enhanced through the application of the adverse outcome pathway (AOP) framework. As AOPs are a relatively new approach in genetic toxicology, this report describes how AOPs could be harnessed to advance MOA analysis of genotoxicity pathways using five example case studies. Each of these genetic toxicology AOPs proposed for further development includes the relevant molecular initiating events, key events, and adverse outcomes (AOs), identification and/or further development of the appropriate assays to link an agent to these events, and discussion regarding the biological plausibility of the proposed AOP. A key difference between these proposed genetic toxicology AOPs versus traditional AOPs is that the AO is a genetic toxicology endpoint of potential significance in risk characterization, in contrast to an adverse state of an organism or a population. The first two detailed case studies describe provisional AOPs for aurora kinase inhibition and tubulin binding, leading to the common AO of aneuploidy. The remaining three case studies highlight provisional AOPs that lead to chromosome breakage or mutation via indirect DNA interaction (inhibition of topoisomerase II, production of cellular reactive oxygen species, and inhibition of DNA synthesis). These case studies serve as starting points for genotoxicity AOPs that could ultimately be published and utilized by the broader toxicology community and illustrate the practical considerations and evidence required to formalize such AOPs so that they may be applied to genetic toxicity evaluation schemes. Environ. Mol. Mutagen. 61:114–134, 2020. © 2019 Wiley Periodicals, Inc.  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