全文获取类型
收费全文 | 209324篇 |
免费 | 3166篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 1438篇 |
儿科学 | 7744篇 |
妇产科学 | 3988篇 |
基础医学 | 21198篇 |
口腔科学 | 2140篇 |
临床医学 | 18085篇 |
内科学 | 36874篇 |
皮肤病学 | 1247篇 |
神经病学 | 19655篇 |
特种医学 | 9461篇 |
外科学 | 31660篇 |
综合类 | 2707篇 |
一般理论 | 55篇 |
预防医学 | 22353篇 |
眼科学 | 3180篇 |
药学 | 11437篇 |
中国医学 | 691篇 |
肿瘤学 | 18686篇 |
出版年
2023年 | 181篇 |
2022年 | 341篇 |
2021年 | 776篇 |
2020年 | 461篇 |
2019年 | 789篇 |
2018年 | 22706篇 |
2017年 | 17860篇 |
2016年 | 20035篇 |
2015年 | 1700篇 |
2014年 | 1928篇 |
2013年 | 2488篇 |
2012年 | 9479篇 |
2011年 | 23588篇 |
2010年 | 20165篇 |
2009年 | 12697篇 |
2008年 | 21848篇 |
2007年 | 24025篇 |
2006年 | 3010篇 |
2005年 | 4451篇 |
2004年 | 5584篇 |
2003年 | 6425篇 |
2002年 | 4440篇 |
2001年 | 473篇 |
2000年 | 543篇 |
1999年 | 445篇 |
1998年 | 602篇 |
1997年 | 562篇 |
1996年 | 408篇 |
1995年 | 374篇 |
1994年 | 363篇 |
1993年 | 308篇 |
1992年 | 200篇 |
1991年 | 219篇 |
1990年 | 250篇 |
1989年 | 202篇 |
1988年 | 156篇 |
1987年 | 151篇 |
1986年 | 112篇 |
1985年 | 135篇 |
1984年 | 175篇 |
1983年 | 177篇 |
1982年 | 218篇 |
1981年 | 167篇 |
1980年 | 198篇 |
1979年 | 95篇 |
1978年 | 82篇 |
1977年 | 84篇 |
1976年 | 68篇 |
1974年 | 87篇 |
1938年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Henry Havel Gregory Finch Pamela Strode Marc Wolfgang Stephen Zale Iulian Bobe Hagop Youssoufian Matthew Peterson Maggie Liu 《The AAPS journal》2016,18(6):1373-1378
Advancing nanomedicines from concept to clinic requires integration of new science with traditional pharmaceutical development. The medical and commercial success of nanomedicines is greatly facilitated when those charged with developing nanomedicines are cognizant of the unique opportunities and technical challenges that these products present. These individuals must also be knowledgeable about the processes of clinical and product development, including regulatory considerations, to maximize the odds for successful product registration. This article outlines these topics with a goal to accelerate the combination of academic innovation with collaborative industrial scientists who understand pharmaceutical development and regulatory approval requirements—only together can they realize the full potential of nanomedicines for patients. 相似文献
12.
13.
M. Alexandra Friedman Charlotte M. Niznik Janelle R. Bolden Lynn M. Yee 《Journal of community health》2016,41(2):354-358
While peer support has been investigated in multiple clinical contexts, its application to the postpartum setting is unknown. The aim was to assess acceptability of a postpartum peer support program for women with diabetes. Observational survey-based needs assessment of forty low-income women with diabetes, receiving care at a major medical institution. Mean age and gravidity were 30.7 years and 3.15 ± 1.67 respectively. 45 % expressed interest in a “buddy.” There was no significant difference between groups desiring and not desiring this program. A majority of respondents desired telephone, text messaging, and in-person contacts (79.2, 72.1, 83.8 %), with 72.5 % of patients desiring diabetes-related activities during clinic waiting time. Many women desire a postpartum diabetes reciprocal peer program for support outside of clinician visits. Patients are receptive to educational services during their wait and outside of clinic time, a potentially valuable opportunity to share important health information. 相似文献
14.
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15.
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
16.
Rebecca Wright Caleb Ferguson Mustafa Bodrick Hanan Balkhy Debra Jackson Patricia M. Davidson 《Journal of clinical nursing》2020,29(13-14):2723-2729
17.
Jennifer C. Sasaki Ashley Allemang Steven M. Bryce Laura Custer Kerry L. Dearfield Yasmin Dietz Azeddine Elhajouji Patricia A. Escobar Albert J. Fornace Jr Roland Froetschl Sheila Galloway Ulrike Hemmann Giel Hendriks Heng-Hong Li Mirjam Luijten Gladys Ouedraogo Lauren Peel Stefan Pfuhler Daniel J. Roberts Véronique Thybaud Jan van Benthem Carole L. Yauk Maik Schuler 《Environmental and molecular mutagenesis》2020,61(1):114-134
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
18.
19.
Konrad Matyja Anna Małachowska-Jutsz Anna K. Mazur Kazimierz Grabas 《Ecotoxicology (London, England)》2016,25(5):924-939
Dehydrogenase activity is frequently used to assess the general condition of microorganisms in soil and activated sludge. Many studies have investigated the inhibition of dehydrogenase activity by various compounds, including heavy metal ions. However, the time after which the measurements are carried out is often chosen arbitrarily. Thus, it can be difficult to estimate how the toxic effects of compounds vary during the reaction and when the maximum of the effect would be reached. Hence, the aim of this study was to create simple and useful mathematical model describing changes in dehydrogenase activity during exposure to substances that inactivate enzymes. Our model is based on the Lagergrens pseudo-first-order equation, the rate of chemical reactions, enzyme activity, and inactivation and was created to describe short-term changes in dehydrogenase activity. The main assumption of our model is that toxic substances cause irreversible inactivation of enzyme units. The model is able to predict the maximum direct toxic effect (MDTE) and the time to reach this maximum (TMDTE). In order to validate our model, we present two examples: inactivation of dehydrogenase in microorganisms in soil and activated sludge. The model was applied successfully for cadmium and copper ions. Our results indicate that the predicted MDTE and TMDTE are more appropriate than EC50 and IC50 for toxicity assessments, except for long exposure times. 相似文献
20.