全文获取类型
收费全文 | 1353206篇 |
免费 | 101584篇 |
国内免费 | 7171篇 |
专业分类
耳鼻咽喉 | 18749篇 |
儿科学 | 43223篇 |
妇产科学 | 38988篇 |
基础医学 | 196336篇 |
口腔科学 | 36919篇 |
临床医学 | 118130篇 |
内科学 | 263501篇 |
皮肤病学 | 27298篇 |
神经病学 | 103407篇 |
特种医学 | 52689篇 |
外国民族医学 | 398篇 |
外科学 | 205045篇 |
综合类 | 39359篇 |
现状与发展 | 15篇 |
一般理论 | 311篇 |
预防医学 | 97991篇 |
眼科学 | 31149篇 |
药学 | 106223篇 |
81篇 | |
中国医学 | 6806篇 |
肿瘤学 | 75343篇 |
出版年
2021年 | 11416篇 |
2018年 | 14549篇 |
2017年 | 11384篇 |
2016年 | 12361篇 |
2015年 | 15138篇 |
2014年 | 20264篇 |
2013年 | 28349篇 |
2012年 | 39544篇 |
2011年 | 42290篇 |
2010年 | 25310篇 |
2009年 | 23249篇 |
2008年 | 39303篇 |
2007年 | 42096篇 |
2006年 | 42246篇 |
2005年 | 41510篇 |
2004年 | 39049篇 |
2003年 | 37793篇 |
2002年 | 37099篇 |
2001年 | 59768篇 |
2000年 | 61350篇 |
1999年 | 52555篇 |
1998年 | 15465篇 |
1997年 | 14034篇 |
1996年 | 14033篇 |
1995年 | 13271篇 |
1994年 | 12512篇 |
1993年 | 11332篇 |
1992年 | 41499篇 |
1991年 | 40829篇 |
1990年 | 40287篇 |
1989年 | 39066篇 |
1988年 | 36380篇 |
1987年 | 35614篇 |
1986年 | 33918篇 |
1985年 | 32306篇 |
1984年 | 24029篇 |
1983年 | 20885篇 |
1982年 | 12418篇 |
1979年 | 22673篇 |
1978年 | 15895篇 |
1977年 | 13743篇 |
1976年 | 12982篇 |
1975年 | 14211篇 |
1974年 | 16697篇 |
1973年 | 16092篇 |
1972年 | 15333篇 |
1971年 | 14237篇 |
1970年 | 13228篇 |
1969年 | 12736篇 |
1968年 | 11981篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
Katherine M. Duszynski Nicole L. Pratt John W. Lynch Jesia G. Berry Michael S. Gold 《Vaccine》2019,37(2):280-288
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113.
Stress Testing Versus CT Angiography in Patients With Diabetes and Suspected Coronary Artery Disease
Abhinav Sharma Adrian Coles Nishant K. Sekaran Neha J. Pagidipati Michael T. Lu Daniel B. Mark Kerry L. Lee Hussein R. Al-Khalidi Udo Hoffmann Pamela S. Douglas 《Journal of the American College of Cardiology》2019,73(8):893-902
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114.
M. D. Wiles A. El-Nayal G. Elton M. Malaj J. Winterbottom C. Gillies I. K. Moppett K. Bauchmuller 《Anaesthesia》2022,77(2):143-152
Pulse oximetry is used widely to titrate oxygen therapy and for triage in patients who are critically ill. However, there are concerns regarding the accuracy of pulse oximetry in patients with COVID-19 pneumonitis and in patients who have a greater degree of skin pigmentation. We aimed to determine the impact of patient ethnicity on the accuracy of peripheral pulse oximetry in patients who were critically ill with COVID-19 pneumonitis by conducting a retrospective observational study comparing paired measurements of arterial oxygen saturation measured by co-oximetry on arterial blood gas analysis (SaO2) and the corresponding peripheral oxygenation saturation measured by pulse oximetry (SpO2). Bias was calculated as the mean difference between SaO2 and SpO2 measurements and limits of agreement were calculated as bias ±1.96 SD. Data from 194 patients (135 White ethnic origin, 34 Asian ethnic origin, 19 Black ethnic origin and 6 other ethnic origin) were analysed consisting of 6216 paired SaO2 and SpO2 measurements. Bias (limits of agreement) between SaO2 and SpO2 measurements was 0.05% (−2.21–2.30). Patient ethnicity did not alter this to a clinically significant degree: 0.28% (1.79–2.35), −0.33% (−2.47–2.35) and −0.75% (−3.47–1.97) for patients of White, Asian and Black ethnic origin, respectively. In patients with COVID-19 pneumonitis, SpO2 measurements showed a level of agreement with SaO2 values that was in line with previous work, and this was not affected by patient ethnicity. 相似文献
115.
116.
J. Oliveira-Santos R. Santos C. Moreira S. Abreu L. Lopes C. Agostinis-Sobrinho G. Stratton J. Mota 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(8):783-792
Background and aimsThe long-term relations between excessive adiposity in early childhood and unfavourable cardiometabolic profiles in later ages are not yet completely understood. We aimed to assess the associations between birth weight (BW) and BMI from 6 months to 6 years of age, with biomarkers indicative of low-grade inflammation, insulin resistance and lipid profiles in adolescence.Methods and resultsRetrospective school-based study with 415 Portuguese adolescents (220 girls), mean age of 14.08 ± 1.6 years old. Anthropometric data from birth to 6 years old was extracted from individual child health book records. Actual weight and height were measured and BMI calculated. Participants were classified at each time point as normal weight or overweight according to WHO reference values. Biomarkers were obtained from venous blood samples. Linear regressions were used to explore the associations between the biomarkers and early life anthropometric indicators. From 2 years onwards, BMI associated positively with the inflammatory score and HOMA-IR in adolescence. Children who were overweight/obese from 2 to 6 years of age presented significantly higher inflammatory score and HOMA-IR later in adolescence. TC/HDL ratio was also positively associated with BMI from the age of 5 years onwards. The associations between BMI and cardiometabolic outcomes remained positive in adolescence, with overweight adolescents presenting a higher inflammatory score, HOMA-IR and TC/HDL than normal weight adolescents.ConclusionA high BMI from an early age was consistently associated with worse inflammatory and lipid profiles and insulin resistance in adolescence. No associations were found between BW and the same studied outcomes. 相似文献
117.
118.
Zheyuan Wang Zhiheng Shi Lu Zhang Huihan Zhang Yawu Zhang 《Pathology, research and practice》2019,215(3):499-505
Profilin 1 (PFN1) is a critical actin-regulatory protein; however, its functional role in hepatocellular carcinoma (HCC) progression remains to be further elucidated. In the present study, we observed that the expression levels of PFN1 were significantly decreased in HCC tissues and cell lines. Low PFN1 expression was significantly correlated with aggressive clinicopathological characteristics and poor prognosis of HCC patients. Further in vitro experiments demonstrated that overexpression of PFN1 remarkably inhibited the proliferation, migration, invasion and EMT of HCC cells. Moreover, we also found that PFN1 was a direct target gene of miR-19a-3p, and in HCC tissues, and there was a significantly inverse correlation between PFN1 mRNA and miR-19a-3p expression. Collectively, our results showed that PFN1 functions as a tumor suppressor in HCC, and might serve as a diagnostic and therapeutic target for HCC patients. 相似文献
119.
120.
综述近年中医药治疗慢性前列腺炎的临床研究,认为本病病因病机之核心在于脾肾亏虚为本,湿热、痰浊、瘀毒为标,病久则伤及脾肾,由实转虚。中医内治法主要以辨证论治、辨病论治或单方验方为主,外治法以中药洗浴、中药灌肠、肛门给药、针灸为主。中医药治疗本病优势明显。应继续完善对中医药作用机制的认识,制订统一的辨证论治及疗效评价标准,针对效果显著的名方开展研究。 相似文献