全文获取类型
收费全文 | 29296篇 |
免费 | 2188篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 345篇 |
儿科学 | 1065篇 |
妇产科学 | 770篇 |
基础医学 | 3935篇 |
口腔科学 | 1008篇 |
临床医学 | 3081篇 |
内科学 | 6057篇 |
皮肤病学 | 472篇 |
神经病学 | 2291篇 |
特种医学 | 1184篇 |
外科学 | 3902篇 |
综合类 | 404篇 |
一般理论 | 46篇 |
预防医学 | 2721篇 |
眼科学 | 442篇 |
药学 | 1903篇 |
1篇 | |
中国医学 | 57篇 |
肿瘤学 | 1856篇 |
出版年
2022年 | 224篇 |
2021年 | 550篇 |
2020年 | 360篇 |
2019年 | 571篇 |
2018年 | 656篇 |
2017年 | 492篇 |
2016年 | 539篇 |
2015年 | 659篇 |
2014年 | 871篇 |
2013年 | 1096篇 |
2012年 | 1615篇 |
2011年 | 1707篇 |
2010年 | 920篇 |
2009年 | 794篇 |
2008年 | 1457篇 |
2007年 | 1538篇 |
2006年 | 1397篇 |
2005年 | 1365篇 |
2004年 | 1213篇 |
2003年 | 1189篇 |
2002年 | 1021篇 |
2001年 | 824篇 |
2000年 | 795篇 |
1999年 | 692篇 |
1998年 | 304篇 |
1997年 | 265篇 |
1996年 | 243篇 |
1995年 | 252篇 |
1994年 | 225篇 |
1993年 | 200篇 |
1992年 | 546篇 |
1991年 | 534篇 |
1990年 | 514篇 |
1989年 | 469篇 |
1988年 | 432篇 |
1987年 | 411篇 |
1986年 | 350篇 |
1985年 | 433篇 |
1984年 | 327篇 |
1983年 | 293篇 |
1982年 | 175篇 |
1979年 | 249篇 |
1978年 | 202篇 |
1977年 | 168篇 |
1976年 | 160篇 |
1975年 | 180篇 |
1974年 | 185篇 |
1973年 | 223篇 |
1972年 | 178篇 |
1971年 | 153篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Venkatesan Chakrapani Thilakavathi Subramanian Pandara Purayil Vijin Ruban Nelson Murali Shunmugam Trace Kershaw 《Global public health》2020,15(3):438-451
ABSTRACTHIV-positive men who have sex with men (HIV+MSM) in India need culturally-relevant interventions to promote safer sex. We tested a multi-level intervention among HIV+MSM that targeted individual, interpersonal, and community factors, based on the Social-Personal and Social Ecological Models. We conducted a 2?×?2 factorial RCT with 119 HIV+MSM randomised to receive either an individual-level intervention (ILI) using motivational interviewing to promote safer sex, a community-level intervention (CLI) to strengthen community norms toward safer sex and reduce stigma among MSM communities, a multi-level intervention combining the individual- and community-level interventions (ILI?+?CLI), or standard-of-care control. Participants completed pre- and post-intervention assessments of a composite sexual risk score and a process evaluation to assess fidelity and satisfaction. Out of the 119 HIV+MSM, 106 (89.0%) completed pre- and post-intervention assessments. Generalised Estimating Equation models showed that both CLI (Incidence Rate Ratio [IRR]?=?.67, 95% CI .47 to .96) and ILI?+?CLI (IRR?=?.66, 95% CI .48 to .91) groups had a statistically significant decrease in sexual risk compared to the standard-of-care. The interventions had high levels of fidelity and satisfaction. This pilot RCT demonstrated feasibility and potential effectiveness of a multi-level intervention that addresses individual, interpersonal and community-level contributors of sexual risk among HIV+MSM. 相似文献
3.
4.
Alessia Scarselli Silvia Di Cesare Claudia Capponi Simona Cascioli Maria L. Romiti Gigliola Di Matteo Alessandra Simonetti Paolo Palma Andrea Finocchi Barbarella Lucarelli Rita M. Pinto Ippolita Rana Giuseppe Palumbo Maurizio Caniglia Paolo Rossi Rita Carsetti Caterina Cancrini Alessandro Aiuti 《Journal of clinical immunology》2015,35(4):373-383
5.
Sarah Hallas Andrea Nelson Susan O'Meara Una Adderley Pauline Meskell Jane Nixon Aonghus O'Loughlin Sebastian Probst Wael Tawfick Thomas Wild Georgina Gethin 《Journal of tissue viability》2021,30(3):317-323
BackgroundA venous leg ulcer is a chronic leg wound caused by poor venous blood circulation in the lower limbs. It is a recurring condition causing pain, malodour, reduced mobility, and depression. Randomised controlled trials evaluating treatments for venous leg ulcers provide important evidence to inform clinical decision-making. However, for findings to be useful, outcomes need to be clinically meaningful, consistently reported across trials, and fully reported. Research has identified the large number of outcomes reported in venous leg ulcer trials, impacting both synthesis of results, and clinical decision-making. To address this, a core outcome set will be developed. A core outcome set is an agreed standardised set of outcomes which should be, as a minimum, measured and reported in all trials which evaluate treatment effectiveness for a given indication. A core outcome set has the potential to reduce research waste, improve the utility of RCTs, reduce reporting bias, facilitate treatment comparisons across different sources of evidence and expedite the production of systematic reviews, meta-analyses and evidence-based clinical guidelines.AimThe aim of this project is to develop a core outcome set for research evaluating the effectiveness of interventions for treating venous leg ulceration.MethodsThrough a scoping review of the literature on venous leg ulceration, we will firstly identify a list of candidate outcome domains (broad categories in relation to what is being measured) from randomised controlled trials and qualitative research, and outcomes (specific methods in relation to what is being measured). In two further stages, we will use the resulting lists of outcome domains and outcomes to design two online surveys. A range of stakeholders will be invited to participate in the surveys and they will be asked to indicate which outcome domains and outcomes are most important and should be considered as core in future research reports. 相似文献
6.
7.
Pedro Lopez Matheus Daros Pinto Ronei Silveira Pinto 《Ultrasound in medicine & biology》2019,45(2):612-616
In the work described here, our aim was to determine, in an elderly population, changes in muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the quadriceps muscles at four time points (0, 5, 10 and 15 min; i.e., T0, T5, T10 and T15, respectively) after changing from a standing to supine position. Twenty-one elderly participants (14 men: 68.1 ± 4.6 y; 8 women: 66.8 ± 4.1 y) were evaluated at four time points. Rectus femoris CSA (RFCSA), MT and EI of the quadriceps femoris (QF) muscles were assessed. EI significantly increased from T0 to T5, T10 and T15 (p < 0.001), whereas no differences were observed between T5 and T15 in the rectus femoris (RFEI), vastus intermedius (VIEI) and quadriceps femoris (QFEI). No differences were observed between any time points in the RFCSA and MT of QF muscles. In summary, these results suggest that periods >5 min are not necessary to obtain consistent MT and EI measurements of quadriceps femoris muscles in the elderly population. 相似文献
8.
Shylo R. Johnson Dennis Slate Kathleen M. Nelson Amy J. Davis Samual A. Mills John T. Forbes Kurt C. VerCauteren Amy T. Gilbert Richard B. Chipman 《Viruses》2021,13(2)
Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA. 相似文献
9.
Paula Cristina Galati Paula Garcia Chiarello Belinda Pinto Simões 《Nutrition and cancer》2016,68(1):86-93
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy. 相似文献
10.