收费全文 | 235079篇 |
免费 | 14873篇 |
国内免费 | 989篇 |
耳鼻咽喉 | 2523篇 |
儿科学 | 5989篇 |
妇产科学 | 4415篇 |
基础医学 | 29291篇 |
口腔科学 | 4320篇 |
临床医学 | 24051篇 |
内科学 | 49550篇 |
皮肤病学 | 3221篇 |
神经病学 | 23654篇 |
特种医学 | 10110篇 |
外国民族医学 | 13篇 |
外科学 | 37006篇 |
综合类 | 2536篇 |
现状与发展 | 1篇 |
一般理论 | 177篇 |
预防医学 | 16515篇 |
眼科学 | 5529篇 |
药学 | 15480篇 |
1篇 | |
中国医学 | 319篇 |
肿瘤学 | 16240篇 |
2023年 | 1335篇 |
2022年 | 2191篇 |
2021年 | 5333篇 |
2020年 | 3043篇 |
2019年 | 5052篇 |
2018年 | 6048篇 |
2017年 | 4441篇 |
2016年 | 4847篇 |
2015年 | 5730篇 |
2014年 | 8346篇 |
2013年 | 11243篇 |
2012年 | 17273篇 |
2011年 | 18006篇 |
2010年 | 10066篇 |
2009年 | 9309篇 |
2008年 | 15859篇 |
2007年 | 16652篇 |
2006年 | 16193篇 |
2005年 | 16052篇 |
2004年 | 15100篇 |
2003年 | 13783篇 |
2002年 | 13182篇 |
2001年 | 1926篇 |
2000年 | 1426篇 |
1999年 | 2001篇 |
1998年 | 2783篇 |
1997年 | 2212篇 |
1996年 | 1922篇 |
1995年 | 1761篇 |
1994年 | 1526篇 |
1993年 | 1492篇 |
1992年 | 977篇 |
1991年 | 923篇 |
1990年 | 782篇 |
1989年 | 741篇 |
1988年 | 676篇 |
1987年 | 612篇 |
1986年 | 635篇 |
1985年 | 678篇 |
1984年 | 908篇 |
1983年 | 786篇 |
1982年 | 1033篇 |
1981年 | 964篇 |
1980年 | 835篇 |
1979年 | 464篇 |
1978年 | 514篇 |
1977年 | 446篇 |
1976年 | 419篇 |
1975年 | 314篇 |
1974年 | 310篇 |
Objective
To determine whether differences in combination DTaP vaccine types at 2, 4 and 6?months of age were associated with mortality (all-cause or non-specific), within 30?days of vaccination.Design
Observational nationwide cohort study.Setting
Linked population data from the Australian Childhood Immunisation Register and National Death Index.Participants
Australian infants administered a combination trivalent, quadrivalent or hexavalent DTaP vaccine (DTaP types) between January 1999 and December 2010 at 2, 4 and 6?months as part of the primary vaccination series. The study population included 2.9, 2.6, & 2.3?million children in the 2, 4 and 6?month vaccine cohorts, respectively.Main outcome measures
Infants were evaluated for the primary outcome of all-cause mortality within 30?days. A secondary outcome was non-specific mortality (unknown cause of death) within 30?days of vaccination. Non-specific mortality was defined as underlying or other cause of death codes, R95 ‘Sudden infant death syndrome’, R96 ‘Other sudden death, cause unknown’, R98 ‘Unattended death’, R99 ‘Other ill-defined and unspecified cause of mortality’ or where no cause of death was recorded.Results
The rate of 30?day all-cause mortality was low and declined from 127.4 to 59.3 deaths per 100,000 person-years between 2 and 6?month cohorts. When compared with trivalent DTaP vaccines, no elevated risk in all-cause or non-specific mortality was seen with any quadrivalent or hexavalent DTaP vaccines, for any cohort.Conclusion
Use of routine DTaP combination vaccines with differing disease antigens administered during the first six months of life is not associated with infant mortality. 相似文献Background
The optimal noninvasive test (NIT) for patients with diabetes and stable symptoms of coronary artery disease (CAD) is unknown.Objectives
The purpose of this study was to assess whether a diagnostic strategy based on coronary computed tomographic angiography (CTA) is superior to functional stress testing in reducing adverse cardiovascular (CV) outcomes (CV death or myocardial infarction [MI]) among symptomatic patients with diabetes.Methods
PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) was a randomized trial evaluating an initial strategy of CTA versus functional testing in stable outpatients with symptoms suggestive of CAD. The study compared CV outcomes in patients with diabetes (n = 1,908 [21%]) and without diabetes (n = 7,058 [79%]) based on their randomization to CTA or functional testing.Results
Patients with diabetes (vs. without) were similar in age (median 61 years vs. 60 years) and sex (female 54% vs. 52%) but had a greater burden of CV comorbidities. Patients with diabetes who underwent CTA had a lower risk of CV death/MI compared with functional stress testing (CTA: 1.1% [10 of 936] vs. stress testing: 2.6% [25 of 972]; adjusted hazard ratio: 0.38; 95% confidence interval: 0.18 to 0.79; p = 0.01). There was no significant difference in nondiabetic patients (CTA: 1.4% [50 of 3,564] vs. stress testing: 1.3% [45 of 3,494]; adjusted hazard ratio: 1.03; 95% confidence interval: 0.69 to 1.54; p = 0.887; interaction term for diabetes p value = 0.02).Conclusions
In diabetic patients presenting with stable chest pain, a CTA strategy resulted in fewer adverse CV outcomes than a functional testing strategy. CTA may be considered as the initial diagnostic strategy in this subgroup. (PROspective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]; NCT01174550) 相似文献Areas covered: This review provides an overview of existing pharmacotherapy for osteoporosis in women and explore state-of–the-art and emerging therapies to prevent bone loss, with an emphasis on the mechanism of action, indications and side effects.
Expert opinion: Bisphosphonates appear to be a reliable and cost-effective option, whereas denosumab has introduced a simpler dosing regimen and may achieve a linear increase in bone mineral density (BMD) with no plateau being observed, along with continuous anti-fracture efficacy. Abaloparatide, a parathyroid-hormone-related peptide (PTHrP)-analogue, approved by the FDA in April 2017, constitutes the first new anabolic osteoporosis drug in the US for nearly 15 years and has also proven its anti-fracture efficacy. Romosozumab, a sclerostin inhibitor, which induces bone formation and suppresses bone resorption, has also been developed and shown a significant reduction in fracture incidence; however, concerns have arisen with regard to increased cardiovascular risk. 相似文献