收费全文 | 376521篇 |
免费 | 21499篇 |
国内免费 | 1094篇 |
耳鼻咽喉 | 4942篇 |
儿科学 | 10973篇 |
妇产科学 | 7809篇 |
基础医学 | 50936篇 |
口腔科学 | 8887篇 |
临床医学 | 35537篇 |
内科学 | 74714篇 |
皮肤病学 | 7280篇 |
神经病学 | 37713篇 |
特种医学 | 16128篇 |
外国民族医学 | 36篇 |
外科学 | 58703篇 |
综合类 | 3163篇 |
现状与发展 | 1篇 |
一般理论 | 219篇 |
预防医学 | 24479篇 |
眼科学 | 8629篇 |
药学 | 25347篇 |
1篇 | |
中国医学 | 511篇 |
肿瘤学 | 23106篇 |
2023年 | 2075篇 |
2022年 | 2626篇 |
2021年 | 6456篇 |
2020年 | 4128篇 |
2019年 | 6388篇 |
2018年 | 8903篇 |
2017年 | 6927篇 |
2016年 | 8005篇 |
2015年 | 8502篇 |
2014年 | 11377篇 |
2013年 | 16647篇 |
2012年 | 24139篇 |
2011年 | 25651篇 |
2010年 | 14407篇 |
2009年 | 12248篇 |
2008年 | 23560篇 |
2007年 | 24854篇 |
2006年 | 24221篇 |
2005年 | 23982篇 |
2004年 | 22630篇 |
2003年 | 21379篇 |
2002年 | 20642篇 |
2001年 | 7579篇 |
2000年 | 8556篇 |
1999年 | 6090篇 |
1998年 | 4325篇 |
1997年 | 3462篇 |
1996年 | 2897篇 |
1995年 | 2572篇 |
1994年 | 2325篇 |
1993年 | 2254篇 |
1992年 | 1952篇 |
1991年 | 1815篇 |
1990年 | 1645篇 |
1989年 | 1598篇 |
1988年 | 1389篇 |
1987年 | 1416篇 |
1986年 | 1294篇 |
1985年 | 1546篇 |
1984年 | 1706篇 |
1983年 | 1433篇 |
1982年 | 1699篇 |
1981年 | 1566篇 |
1980年 | 1418篇 |
1979年 | 1097篇 |
1978年 | 1060篇 |
1977年 | 1011篇 |
1976年 | 874篇 |
1975年 | 846篇 |
1974年 | 804篇 |
Method: Socio-demographics, early-life adversity (ELA), individual quality of life (iQoL), and mental and physical health of 270 individuals (Mage = 66.82 years, 71.5% female) were assessed. Polynomial regressions and mediation analyses were conducted.
Results: Significant inverse U-shaped associations were found between ELA and iQoL (β = ?.59, p = .005) and between ELA and mental health (β = ?.64, p = .002), but not between ELA and physical health. Furthermore, mental health significantly mediated the relationship between ELA and iQoL (b = ?.84, BCa CI [?1.66, ?.27]).
Conclusion: Highest level of individual quality of life (i.e. successful aging) was related to a moderate amount of ELA. Additionally, mental health significantly mediated this relationship. These findings suggest that some amount of ELA could be beneficial for successful aging. Resource-focused interventions are needed to improve health and promote successful aging for an underdetected, at-risk subgroup with low early-life adversity. 相似文献
Objective
Low psoas muscle area is shown to be an indicator for worse postoperative outcome in patients undergoing vascular surgical. Additionally, it has been associated with longer durations of hospital stay in patients with cancer who undergo surgery and subsequently greater health care costs in Europe and the United States. We sought to evaluate this effect on hospital expenditure for patients undergoing vascular repair in a health care system with universal access.Methods
Skeletal muscle mass was assessed on preoperative abdominal computed tomography scans of patients undergoing open aortic aneurysm repair in a retrospective fashion. The skeletal muscle index (SMI) was used to define low muscle mass. Health care costs were obtained for all patients and the relationship between a low SMI and higher costs was explored using linear regression and cross-sectional analysis.Results
We included 156 patients (81.5% male) with a median age of 72 years undergoing elective surgery for infrarenal abdominal aortic aneurysm in this analysis. The median SMI for patients with low skeletal muscle mass was 53.21 cm2/kg and for patients without, 70.07 cm2/kg. Hospital duration of stay was 2 days longer in patients with low skeletal muscle mass as compared with patients with normal (14 days vs 11 days; P = .001), as was duration of intensive care stay (3 days vs 1 day; P = .01). The median overall hospital costs were €10,460 higher for patients with a low SMI as compared with patients with a normal physical constitution (€53,739 [interquartile range, €45,007-€62,471] vs €43,279 [interquartile range, €39,509-€47,049]; P = .001). After confounder adjustment, a low SMI was associated with a 14.68% cost increase in overall hospital costs, for a cost increase of €6521.Conclusions
Low skeletal muscle mass is independently associated with higher hospital as well as intensive care costs in patients undergoing elective aortic aneurysm repair. Strategies to reduce this risk factor are warranted for these patients. 相似文献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 focuses on current treatments and the future outlook for allergic rhinitis. Pharmacotherapy includes mast cell stabilizers, antihistamines, glucocorticosteroids (GCSs), leukotriene receptor antagonists, and nasal decongestants. Nasal GCSs are currently regarded as the most effective treatment and are considered first-line therapy together with non-sedating antihistamines. The new formulation MP29-02 combines the nasal GCS fluticasone propionate with azelastine in one single spray and has achieved greater improvements than those under monotherapy with modern GCSs or antihistamines. Furthermore, this review discusses allergen immunotherapy alone and in combination with modern monoclonal antibodies.
Expert opinion: Despite the variety of medications for allergic rhinitis, ranging from general symptomatic agents like GCSs or decongestants, to more specific ones like histamine receptor or leukotriene blockers, to causal therapy like immunotherapy, many patients still experience treatment failures or unsatisfactory results. The ultimate goal may be to endotype every downstream pathway separately in order to offer patients individualized, targeted therapy with specific antibodies against the respective pathway. 相似文献