全文获取类型
收费全文 | 2314篇 |
免费 | 122篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 49篇 |
妇产科学 | 53篇 |
基础医学 | 316篇 |
口腔科学 | 24篇 |
临床医学 | 188篇 |
内科学 | 395篇 |
皮肤病学 | 44篇 |
神经病学 | 98篇 |
特种医学 | 250篇 |
外科学 | 430篇 |
综合类 | 162篇 |
预防医学 | 176篇 |
眼科学 | 63篇 |
药学 | 120篇 |
1篇 | |
中国医学 | 7篇 |
肿瘤学 | 96篇 |
出版年
2023年 | 15篇 |
2022年 | 8篇 |
2021年 | 36篇 |
2020年 | 22篇 |
2019年 | 35篇 |
2018年 | 46篇 |
2017年 | 35篇 |
2016年 | 37篇 |
2015年 | 41篇 |
2014年 | 69篇 |
2013年 | 113篇 |
2012年 | 147篇 |
2011年 | 156篇 |
2010年 | 89篇 |
2009年 | 88篇 |
2008年 | 132篇 |
2007年 | 132篇 |
2006年 | 102篇 |
2005年 | 109篇 |
2004年 | 107篇 |
2003年 | 90篇 |
2002年 | 89篇 |
2001年 | 59篇 |
2000年 | 54篇 |
1999年 | 53篇 |
1998年 | 54篇 |
1997年 | 56篇 |
1996年 | 51篇 |
1995年 | 34篇 |
1994年 | 34篇 |
1993年 | 29篇 |
1992年 | 21篇 |
1991年 | 27篇 |
1990年 | 23篇 |
1989年 | 38篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 25篇 |
1984年 | 7篇 |
1983年 | 13篇 |
1982年 | 18篇 |
1981年 | 9篇 |
1980年 | 14篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 7篇 |
1971年 | 8篇 |
排序方式: 共有2478条查询结果,搜索用时 0 毫秒
51.
Judith I. Tsui Bradley J. Anderson David R. Strong Michael D. Stein 《The American journal of drug and alcohol abuse》2014,40(2):163-169
Background: Few studies have assessed associations between craving and subsequent opioid use. We prospectively evaluated the relative utility of two craving questionnaires to predict opioid use among opioid-dependent patients in outpatient treatment. Method: Opioid-dependent patients (n?=?147) initiating buprenorphine treatment were assessed every two weeks for 3 months. Craving was measured using the: (1) Desires for Drug Questionnaire (DDQ) and (2) Penn Alcohol-Craving Scale adapted for opioid craving (PCS). Multi-level logistic regression models estimated the effects of craving on the likelihood of opioid use. Craving assessed at time t was entered as a time-varying predictor of opioid use at time t?+?1. Results: Craving scores plateaued at approximately 2 weeks after initiation of buprenorphine. In adjusted regression models, a 1-point increase in PCS scores (on a 7-point scale) was associated with a significant increase in the odds of opioid use at the subsequent assessment (OR?=?1.27, 95% CI 1.08; 1.49, p?0.01). The odds of opioid use at the subsequent follow-up assessment increased significantly as DDQ desire and intention scores increased (OR?=?1.25, 95%CI 1.03; 1.51, p?0.05), but was not significantly associated with DDQ negative reinforcement (OR?=?1.01, 95%CI 0.88; 1.17, p?>?0.05) or DDQ control (OR?=?0.97, 95%CI 0.85; 1.11, p?>?0.05) scores. Conclusion: Self-reported craving for opioids was modestly associated with subsequent relapse to opioid use among a cohort of patients treated with buprenorphine. Assessment of craving may provide clinical utility in predicting relapse among treated opioid-dependent patients. 相似文献
52.
The current body of research lacks a meta‐analysis of the relationship between hair cortisol concentration (HCC) and anthropometry in children. Therefore, this systematic review and meta‐analysis was conducted to examine this relationship and explore possible moderators between HCC and body mass index (BMI/BMI z‐score). Eleven databases were searched: CINAHL, Cochrane, Embase, PsycEXTRA, Psychology and Behavioral Sciences, PsycINFO, PubMed, Scopus, Social Sciences Full Text, Sociological Abstracts and Web of Sciences. Random‐effects models and exploratory moderator analyses with mixed‐effects models were performed using the Comprehensive Meta‐Analysis software. The meta‐analysis showed small positive correlations between HCC and BMI (r = 0.08, 95% confidence interval [CI]: 0.02, 0.14, n = 18, p = .009), BMI z‐score (r = 0.10, 95% CI: 0.03, 0.16, n = 12, p = .003), waist circumference (r = 0.10, 95% CI: 0.04, 0.17, n = 10, p = .001) and body fat including fat mass index (r = 0.06, 95% CI: 0.02, 0.11, n = 3, p = .005). The relationship between HCC and BMI/BMI z‐score was significantly moderated by children's sex. Results from this meta‐analysis provide initial objective support for a small positive relationship between HCC and anthropometric factors. 相似文献
53.
Contraception and health 总被引:1,自引:0,他引:1
Increasing contraceptive use in developing countries has cut the number of maternal deaths by 40% over the past 20 years, merely by reducing the number of unintended pregnancies. By preventing high-risk pregnancies, especially in women of high parities, and those that would have ended in unsafe abortion, increased contraceptive use has reduced the maternal mortality ratio--the risk of maternal death per 100,000 livebirths--by about 26% in little more than a decade. A further 30% of maternal deaths could be avoided by fulfilment of unmet need for contraception. The benefits of modern contraceptives to women's health, including non-contraceptive benefits of specific methods, outweigh the risks. Contraception can also improve perinatal outcomes and child survival, mainly by lengthening interpregnancy intervals. In developing countries, the risk of prematurity and low birthweight doubles when conception occurs within 6 months of a previous birth, and children born within 2 years of an elder sibling are 60% more likely to die in infancy than are those born more than 2 years after their sibling. 相似文献
54.
Background
The ethnic usage of exotics and indigenous problem plants is a highly debated topic, as legislative requirements over-shadow their potential medicinal value, particularly to treat sexually transmitted infections (STIs). Limited information exists regarding their medicinal value among the Bapedi.Objectives
To ascertain the importance of exotics and indigenous problem plants in the treatment of STIs, a major global primary health care challenge.Methods
A field observation and semi-structured questionnaire focussing on species diversity, types of STIs treated and medicinal preparation as well as application was used to collect data from 34 traditional healers.Results
Seven exotics and three indigenous problem species were identified. These species were used to treat four STIs; with Catharanthus roseus illustrating its dominance in the treatment of gonorrhoea. Some medicinal species used by Bapedi traditional healers have been validated through scientific research or through their extensive use by various cultures in South Africa and other parts of Africa. To the best of our knowledge Alternanthera pungens, Caesalpinia decapetala, Cinnamomum verum, and Citrullus lanatus are reported for the first time in the treatment of the investigated STIs.Conclusions
Exotic and indigenous problem species constitute an important component of the STIs treatment protocol. Their utilization by Bapedi cautions against the narrow-minded approach of indiscriminate eradication, as these species can play a significant role in the primary health care needs of socio-economic vulnerable people. 相似文献55.
56.
57.
Alviar CL Tellez A Wang M Potts P Smith D Tsui M Budzynski W Raizner AE Kleiman NS Lev EI Granada JF Kaluza GL 《Journal of thrombosis and thrombolysis》2012,34(1):91-98
We previously found paclitaxel-eluting polymer-coated stents causing more human platelet-monocyte complex formation than bare metal stents in vitro. Presently, we examined patterns of platelet activation and adhesion after exposure to 6 nanofilm HAp-coated (HAp-nano) stents, 6 HAp-microporous-coated (HAp-micro) stents, 5 HAp sirolimus-eluting microporous-coated (HAp-SES) stents and 5 cobalt-chromium stents (BMS) deployed in an in vitro flow system. Blood obtained from healthy volunteers was circulated and sampled at 0, 10, 30 and 60 min. By flow cytometry, there were no significant differences in P-Selectin expression between the 4 stent types (HAp-nano = 32.5%; HAp-micro = 42.5%, HAp-SES = 10.23%, BMS = 7% change from baseline at 60 min, p = NS); PAC-1 antibody binding (HAp-nano = 11.8%; HAp-micro = 2.9%, HAp-SES = 18%, BMS = 6.4% change from baseline at 60 min, p = NS) or PMC formation (HAp-nano = 21.6%; HAp-micro = 4%, HAp-SES = 6.6%, BMS = 17.4% change from baseline at 60 min, p = NS). The 4 stent types did not differ in the average number of platelet clusters >10 μm in diameter by SEM (HAp-nano = 2.39 ± 5.75; HAp-micro = 2.26 ± 3.43; HAp-SES = 1.93 ± 3.24; BMS = 1.94 ± 2.41, p = NS). The majority of the struts in each stent group were only mildly covered by platelets, (HAp-nano = 80%, HAp-micro = 61%, HAp-SES = 78% and BMS = 52.1%, p = NS). The HAp-microporous-coated stents (ECD) attracted slightly more proteinaceous material than bare metal stents (HAp-micro = 35% struts with complete protein coverage, P < 0.0001 vs. other 3 stent types). In conclusion, biomimetic stent coating with nanofilm or microporous hydroxyapatite, even when eluting low-dose sirolimus, does not increase the platelet activation in circulating human blood, or platelet adhesion to stent surface when compared to bare metal stents in vitro. 相似文献
58.
Purpose
A number of original publications and review articles have addressed the issue of perioperative immune modulation and cancer outcome. The objective of this module is to review current understanding surrounding the pathways involved and the evidence implicating commonly used anesthetic agents.Principal findings
Drugs commonly used in anesthetic practice have been shown to affect various components of the immune system in laboratory animal and human in vitro models. It has been hypothesized that these effects may favour tumour recurrence and metastasis formation. Inhalational agents and opiates have potential negative immunomodulatory effects; on the other hand, regional anesthesia and propofol may have positive effects on immune function modulation. However, the clinical relevance of these studies to human cancer outcome is unknown since clinical trials are equivocal, and results of in vitro and animal model studies cannot be extrapolated to clinical practice. Furthermore, there is a lack of rigorous clinical trials demonstrating clinical outcome benefit for one technique over another. It remains unclear how anesthetic drugs influence the immune system in relation to tumour cell elimination and clinical cancer outcome.Conclusions
Recommendations for a specific anesthetic technique based on cancer outcome alone cannot be made. A pragmatic solution would be to offer regional anesthesia in isolation or combined with propofol infusion to cancer patients if appropriate and if local expertise is available. Regional anesthesia offers excellent analgesia, a low incidence of postoperative nausea and vomiting, and a favourable immunological profile based on current understanding of laboratory evidence. 相似文献59.
60.
Jacklyn Cho BS Brittany Toffey MD Ariel F. Silva NP Ariel Shalev MD Monika M. Safford MD Erica Phillips MD MS Ann Lee BS Faith Wiggins BS MS Elissa Kozlov PhD Emma K. Tsui PhD MPH Nicola Dell PhD Ariel C. Avgar PhD Susan J. Andreae PhD MPH Madeline R. Sterling MD MPH MS 《Health services research》2023,58(3):697-704