全文获取类型
收费全文 | 47971篇 |
免费 | 2201篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 1166篇 |
妇产科学 | 1793篇 |
基础医学 | 4204篇 |
口腔科学 | 1692篇 |
临床医学 | 6081篇 |
内科学 | 8288篇 |
皮肤病学 | 532篇 |
神经病学 | 3359篇 |
特种医学 | 1705篇 |
外科学 | 4275篇 |
综合类 | 359篇 |
现状与发展 | 2篇 |
一般理论 | 20篇 |
预防医学 | 10620篇 |
眼科学 | 543篇 |
药学 | 3011篇 |
1篇 | |
中国医学 | 112篇 |
肿瘤学 | 2336篇 |
出版年
2024年 | 54篇 |
2023年 | 3158篇 |
2022年 | 4539篇 |
2021年 | 4142篇 |
2020年 | 4481篇 |
2019年 | 2665篇 |
2018年 | 2268篇 |
2017年 | 2675篇 |
2016年 | 2665篇 |
2015年 | 2076篇 |
2014年 | 3884篇 |
2013年 | 2733篇 |
2012年 | 1663篇 |
2011年 | 1249篇 |
2010年 | 2239篇 |
2009年 | 1980篇 |
2008年 | 864篇 |
2007年 | 925篇 |
2006年 | 687篇 |
2005年 | 510篇 |
2004年 | 375篇 |
2003年 | 395篇 |
2002年 | 438篇 |
2001年 | 366篇 |
2000年 | 287篇 |
1999年 | 416篇 |
1998年 | 408篇 |
1997年 | 312篇 |
1996年 | 342篇 |
1995年 | 294篇 |
1994年 | 212篇 |
1993年 | 164篇 |
1992年 | 120篇 |
1991年 | 126篇 |
1990年 | 129篇 |
1989年 | 77篇 |
1988年 | 101篇 |
1987年 | 30篇 |
1986年 | 22篇 |
1985年 | 38篇 |
1984年 | 21篇 |
1983年 | 14篇 |
1982年 | 20篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1978年 | 7篇 |
1976年 | 8篇 |
1974年 | 8篇 |
1973年 | 10篇 |
1972年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
91.
Study objectiveFibrinogen concentrate is used to treat severe postpartum hemorrhage despite limited evidence of its effectiveness in obstetric settings. We aimed to explore the association between its administration and maternal outcomes in women with severe postpartum hemorrhage.Design, setting and patientsThis secondary analysis of the EPIMOMS prospective population-based study, exploring severe maternal morbidity, as defined by national expert consensus (2012–2013, 182,309 deliveries, France), included all women with severe postpartum hemorrhage and transfused with red blood cells during active bleeding.MeasurementsThe primary endpoint was maternal near-miss or death, and the secondary endpoint the total number of red blood cells units transfused.InterventionsWe studied fibrinogen concentrate administration as a binary variable and then by the timing of its administration. We used multivariable analysis and propensity score matching to account for potential indication bias.Main resultsAmong the 730 women with severe postpartum hemorrhage and transfused, 313 (42.9%) received fibrinogen concentrate, and 142 (19.5%) met near-miss criteria or died. The risk of near-miss or death was not significantly lower among the women treated with fibrinogen concentrate than among those not treated, in either the multivariable analysis (adjusted RR = 1.03; 95% CI, 0.72–1.49; P = 0.855) or the propensity score analysis (RR = 0.85; 95% CI, 0.55–1.32; P = 0.477). Among women treated with fibrinogen concentrate, administration more than three hours after red blood cell transfusion started was associated with a higher risk of near-miss or death than administration before or within 30 min after the transfusion began (adjusted RR = 2.07; 95% CI, 1.10–3.89; P = 0.024). Results were similar for the secondary endpoint.ConclusionsThe use of fibrinogen concentrate in severe postpartum hemorrhage needing red blood cell transfusion during active bleeding is not associated with improved maternal outcomes. 相似文献
92.
93.
94.
《Diagnostic microbiology and infectious disease》2020,96(1):114920
We evaluated the performance of the Luminex ARIES® C. difficile Assay on 984 stool specimens prospectively collected from patients being tested for CDI at 4 clinical laboratories in the United States. Results were compared to direct and enriched toxigenic culture. Positive percent agreement (PPA) of the ARIES® C. difficile Assay was 98.1% versus direct toxigenic culture, and sensitivity versus direct plus enriched toxigenic culture was 90.5%. Negative percent agreement (NPA) of the ARIES® C. difficile Assay against direct culture was 92.6%, and specificity versus direct plus enriched toxigenic culture was 95.8%. The ARIES® C. difficile Assay was also compared to the results of routine (molecular, antigen, and/or toxin) methods for C. difficile testing used at each institution. The PPA of the ARIES® C. difficile Assay ranged from 82.9% to 100%. NPA values against these commercial assays ranged from 94.5% to 100%. 相似文献
95.
Christian Holm Hansen Shelley Lees Saidi Kapiga Janet Seeley Tony Barnett 《Global public health》2020,15(3):402-413
ABSTRACTMeasuring hope reliably and accurately remains an important research objective, not least in less prosperous settings where ‘holding on to hope’ may be critically important in the struggle against adverse life conditions. The State Hope Scale was designed for use in the US. Despite reported application in diverse cultures and using translations the scale has not been extensively validated outside US populations. This study contributes to a larger project exploring the measurement of hope and provides a critique of Snyder’s scale as used in a Tanzanian female population of 1021 urban microfinance participants. We evaluate the scale’s validity through assessment of the empirical distribution of scores, item response profiles, internal consistency and discriminatory ability. Participants mostly scored very high and many reached very near the maximum attainable score. Hardly any endorsed the negative half of the response scale. Several problems are discussed including poor discrimination and strong evidence of acquiescence response bias. We also found little association of the scale scores with hypothesised correlates of hope. Future improvements on the measurement of hope are recommended, especially in studies outside the narrow Western context in which the scale was devised. 相似文献
96.
97.
《Developmental and comparative immunology》2015,48(2):205-214
Specificity, antibody isotype distribution and levels, of natural autoantibodies (NAAb) may be potential informative parameters for immune mediated natural disease resistance, immune modulation, and maintenance of physiological homeostasis. In a previous study we detected IgM and IgG antibodies to liver antigens in plasma from 1 year old chickens. Auto-immune profiles directed towards liver antigens differed between chicken lines divergently selected for specific antibody responses to sheep red blood cells. In the present study we measured the presence and typed levels and antibody isotypes (IgG and IgM) of NAAb binding the ‘auto-antigen’ complex chicken liver cell lysate (CLL) in plasma samples obtained from chickens at 5 weeks and at 1-year of age, respectively, by quantitative western blotting.Extensive staining patterns of plasma antibodies binding CLL were found for both isotypes and at both ages in all birds. At both ages, IgM and IgG bound similar numbers of CLL antigens, which remained almost constant for IgM, whereas the number of IgG stained bands in time was enhanced. Significant differences of binding patterns of NAAb (stained antigen fragments of CLL and staining intensity) were detected between the three different chicken lines at both ages and between both ages, and lines could be clustered on the basis of their auto-antibody profile. The present results indicate that analysis of the plasma NAAb repertoire of poultry like in mammals could provide a way of distinguishing differences of immune competence (as reflected by the selection criterion of antibody responses) between individuals and lines, and could provide tools to select individual birds for health and other traits. The age-dependency of the auto-immune profile suggest that such profiles may also reflect immune maturation, which should be taken into account when relating an auto-immune profile with other traits. 相似文献
98.
99.
BackgroundDyslipidemia in rheumatoid arthritis (RA) patients is frequently observed, and treatment with anti-rheumatic drugs has an impact on lipid profiles. Pathophysiologically, inflammation leads to decreased blood lipids and lipoproteins; RA treatment reduces inflammation and therefore may increase lipids and lipoproteins. Whether the lipid changes with RA treatment confer an increased risk of cardiovascular disease or just reflect their potentially atheroprotective anti-inflammatory effect is currently unclear due to limited and conflicting data.ObjectiveThe aim of this review is to summarize the current knowledge on the effects of synthetic and biological disease modifying antirheumatic drugs for the treatment of RA on lipid and lipoprotein parameters.ResultsRecent studies on methotrexate emphasize its anti-atherogenic effect. Golimumab combined with methotrexate revealed a trend towards an anti-atherogenic potential. The known pro-atherogenic lipid-spectrum alterations caused by tofacitinib can be effectively treated with atorvastatin. Tocilizumab signals a favorable impact on the extent of lipid modifications when combined with methotrexate. Abatacept indicated a trend towards an anti-atherogenic lipid profile demonstrated by favorable effects on HDL-C and on the TC/HDL-C ratio. Rituximab has beneficial effects on HDL-C and ApoA1, as well as on the ApoB/ApoA1 ratio.Clinical implicationsAnti-rheumatic drugs have various effects on lipid parameters, which in part appear pro-atherogenic. However, because many of these lipid changes may well reflect their potentially atheroprotective anti-inflammatory action the cardiovascular impact of these changes remains unclear. Whatsoever, cardiovascular safety trials for antirheumatic drugs would be valuable. 相似文献
100.
《Injury》2022,53(12):3962-3969
IntroductionEducators are exposed to several work-related hazards. Evidence suggests musculoskeletal pain, psychological distress, and student-inflicted violence-related injuries are common. However, there is little evidence on the burden of workplace injury among Australian educators.AimTo compare incidence of injury claims and duration of compensated time off work between educators and non-educators, and associated factors.MethodsRetrospective cohort study of 1,559,676 Australian workers’ compensation claims, including 84,915 educator claims, lodged between July 2009 to June 2015, from the National Dataset for Compensation-based Statistics. Cases were included if aged 18+ years and working in the education sector less than 100 h per week. Negative binomial regression models estimated the relative risk of making a compensation claim and survival analyses calculated disability duration within educators by sex, age, injury type and mechanism, socioeconomic area, remoteness, and jurisdiction.ResultsCompared to non-educators, educators had lower rates of injury claims and shorter disability durations. However, educators had a higher rate of claims for mental health conditions and assault, with the highest risk being among those in special education and education aides. Among educators, injury claim rates were highest among special educators, education aides, and secondary educators.Discussion and ConclusionThough surveys indicate Australians in the education sector have higher incidences of work-related injuries, this study found lower incidence of injury claims and shorter disability durations than others. Educators’ injury-reporting and absenteeism behaviors may be constrained by ethical, social, and administrative attitudes. Educators had higher rates of claims for mental health and assault-related injury, particularly special educators, and education aides, which suggests a need for targeted prevention efforts. 相似文献