全文获取类型
收费全文 | 290993篇 |
免费 | 25248篇 |
国内免费 | 11010篇 |
专业分类
耳鼻咽喉 | 3349篇 |
儿科学 | 7197篇 |
妇产科学 | 4776篇 |
基础医学 | 37982篇 |
口腔科学 | 6902篇 |
临床医学 | 27974篇 |
内科学 | 37423篇 |
皮肤病学 | 3159篇 |
神经病学 | 21916篇 |
特种医学 | 6113篇 |
外国民族医学 | 60篇 |
外科学 | 29023篇 |
综合类 | 45806篇 |
现状与发展 | 31篇 |
一般理论 | 26篇 |
预防医学 | 23856篇 |
眼科学 | 9353篇 |
药学 | 25937篇 |
90篇 | |
中国医学 | 11841篇 |
肿瘤学 | 24437篇 |
出版年
2024年 | 557篇 |
2023年 | 3698篇 |
2022年 | 6985篇 |
2021年 | 10962篇 |
2020年 | 10049篇 |
2019年 | 9215篇 |
2018年 | 9149篇 |
2017年 | 9725篇 |
2016年 | 10225篇 |
2015年 | 10113篇 |
2014年 | 16929篇 |
2013年 | 19068篇 |
2012年 | 15822篇 |
2011年 | 17663篇 |
2010年 | 14966篇 |
2009年 | 14300篇 |
2008年 | 14547篇 |
2007年 | 15675篇 |
2006年 | 14179篇 |
2005年 | 13450篇 |
2004年 | 11605篇 |
2003年 | 10184篇 |
2002年 | 7987篇 |
2001年 | 7507篇 |
2000年 | 6204篇 |
1999年 | 5527篇 |
1998年 | 4340篇 |
1997年 | 3865篇 |
1996年 | 3691篇 |
1995年 | 3416篇 |
1994年 | 3051篇 |
1993年 | 2703篇 |
1992年 | 2441篇 |
1991年 | 2128篇 |
1990年 | 1861篇 |
1989年 | 1659篇 |
1988年 | 1471篇 |
1987年 | 1215篇 |
1986年 | 1030篇 |
1985年 | 1250篇 |
1984年 | 1183篇 |
1983年 | 768篇 |
1982年 | 927篇 |
1981年 | 758篇 |
1980年 | 647篇 |
1979年 | 511篇 |
1978年 | 414篇 |
1977年 | 344篇 |
1976年 | 371篇 |
1975年 | 229篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
92.
93.
《Health & place》2019
The objective of this paper was to assess the link between premature mortality and a combination of neighbourhood contextual (environmental and health) and compositional (socioeconomic and demographic) characteristics. We statistically and spatially examined six environmental variables (ultrafine particles, carcinogenic and non-carcinogenic pollutants, pollution released to air, tree cover, and walkability index), six health service indicators (number health providers, breast, colorectal and cervical cancer screening uptake rates, student nutrition program uptake rates, and healthy food index), and eight socioeconomic indicators (total income, Gini coefficient, two age categories – below and above 40 years, proportion of females to males, visible minorities, Indigenous peoples, education, less than grade 9) among 140 neighbourhoods of the City of Toronto in Ontario (Canada). We applied principal component analysis to identify patterns and to reduce the number of explanatory variables into combined component axes that represent unique variation in these confounded and overlapping factors. We then applied regression analysis to model the relationship between the indices of enviro-health and socioeconomics and their potential relationship with premature mortality. Residual spatial analysis was used to investigate any remaining spatial structure (such as neighbourhoods with higher residual premature mortality rates). Neighbourhood Equity Index was correlated with our enviro-health and socioeconomic indices. Premature mortality within neighbourhoods was predicted by poor cancer screenings, pollution, lack of tree canopy, increased uptake of student nutrition programs and high walkability index. A negative association between premature mortality and pollution was associated low walkability index and presence of visible minorities within neighbourhoods. There was some unexplained residual spatial variation in our model of premature mortality - especially along the shores of Lake Ontario and in neighbourhoods with major highways or road corridors: premature mortality in Toronto neighbourhoods was higher than expected along highway-corridor neighbourhoods and shorelines. Our analysis revealed a significant relationship between neighbourhood contextual features – both environmental and health – and premature mortality, suggesting that these contextual components of neighbourhoods can predict rates of urban premature mortality in Toronto. 相似文献
94.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(10):1030-1039
Background and aimThis network meta-analysis (NMA) compares the effects of different types of olive oil (OO) on cardiovascular risk factors.Methods and resultsLiterature search was conducted on three electronic databases (Medline, Web of Science, and Cochrane Central). Inclusion criteria: Randomized controlled trials (RCTs) (≥3 weeks duration of intervention) comparing at least two of the following types of OO: refined OO (ROO), mixed OO (MOO), low phenolic (extra) virgin OO (LP(E)VOO), and high phenolic (extra) virgin OO (HP(E)VOO). Random-effects NMA was performed for seven outcomes; and surface under the cumulative ranking curve (SUCRA) was estimated, using an analytical approach (P-score). Thirteen RCTs (16 reports) with 611 mainly healthy participants (mean age: 26–70 years) were identified. No differences for total cholesterol, HDL-cholesterol, triacylglycerols, and diastolic blood pressure were observed comparing ROO, MOO, LP(E)VOO and HP(E)VOO. HP(E)VOO slightly reduce LDL-cholesterol (LDL-C) compared to LP(E)VOO (mean difference [MD]: −0.14 mmol/L, 95%–CI: −0.28, −0.01). Both, HP(E)VOO and LP(E)VOO reduces SBP compared to ROO (range of MD: −2.99 to −2.87 mmHg), and HP(E)VOO may improve oxidized LDL-cholesterol (oxLDL-C) compared to ROO (standardized MD: −0.68, 95%–CI: −1.31, −0.04). In secondary analyses, EVOO may reduce oxLDL-C compared to ROO, and a dose-response relationship between higher intakes of phenolic compounds from OO and lower SBP and oxLDL-C values was detected. HP(E)VOO was ranked as best treatment for LDL-C (P-score: 0.83), oxLDL-C (0.88), and SBP (0.75).ConclusionsHP(E)VOO may improve some cardiovascular risk factors, however, public health implications are limited by overall low or moderate certainty of evidence. 相似文献
95.
目的:研究乳腺癌细胞中转录调节因子c-Myb的表达对肺转移的影响及其分子机制。方法:构建c-Myb高表达的4T1乳腺癌细胞株,种植小鼠构建乳腺癌动物模型,检测实验动物肺转移情况,通过荷瘤抑制试验检测肺转移抑制效果。提取组织进行荧光PCR检测相关炎症因子的表达。利用Medisapiens数据库的生物信息学资源,对c-Myb和Ccl2的表达与乳腺癌患者的预后进行分析。结果:高表达c-Myb的荷瘤小鼠肺部转移灶明显减少,其中炎症相关因子表达受限。由数据库分析得出,c-Myb高表达患者生存期得以延长。结论:乳腺癌中c-Myb的表达能够通过炎症因子Ccl2抑制肺转移从而延长患者生存期。 相似文献
96.
97.
98.
《Clinical genitourinary cancer》2022,20(3):e217-e226
Background: Intraductal carcinoma and cribriform (IDC/C) tumor features are well-established prognosticators of biochemical recurrence (BCR), metastasis, and prostate cancer (PCa)-specific mortality. However, approximately 70% of PCa patients undergoing a radical prostatectomy are IDC/C negative, yet up-to 20% of these patients progress and experience BCR. Thus, tumor histopathologic characteristics such as IDC/C alone are limited in their ability to predict disease progression. Conversely, several nomograms such as Cancer of the Prostate Risk Assessment-Surgery (CAPRA-S) have been developed to aid in the prognostication of BCR, but not yet widely applied in clinical settings. Materials and methods: In this study, we assessed the combined prognostic utility of IDC/C, and CAPRA-S for BCR in 3 PCa patient cohorts. Results: CAPRA-S+IDC/C improved the predictive accuracy of BCR in all 3 cohorts (P < .001). Specifically, among IDC/C negative cases, CAPRA-S improved the prognostication of BCR in low-risk (Cohort 1; P < .001, Cohort 2; P < .001, Cohort 3; P = .003), intermediate (Cohort 1; P < .001, Cohort 2; P = .006, Cohort 3; P = .03) and high-risk (Cohort 1-3; P < .001) patients. Conversely, IDC/C improved the prognostication of BCR among CAPRA-S low-risk (Cohorts 1; P < .001 and Cohort 3; P = .003) patients. Conclusion: Our results suggest the investigation of histopathological IDC/C features in CAPRA-S low-risk patients and conversely, nomogram CAPRA-S among IDC/C negative patients improves the identification of patients likely to experience BCR, which would otherwise be missed through current assessment regimens. These patients can be offered more intensive monitoring and adjuvant therapies upfront to circumvent the development of recurrent cancer or overtreatment at the time of surgery. 相似文献
99.
《Saudi Pharmaceutical Journal》2022,30(6):655-668
Most vaccines approved by regulatory bodies are administered via intramuscular or subcutaneous injections and have shortcomings, such as the risk of needle-associated blood infections, pain and swelling at the injection site. Orally administered vaccines are of interest, as they elicit both systemic and mucosal immunities, in which mucosal immunity would neutralize the mucosa invading pathogen before the onset of an infection. Hence, oral vaccination can eliminate the injection associated adverse effects and enhance the person's compliance. Conventional approaches to manufacturing oral vaccines, such as coacervation, spray drying, and membrane emulsification, tend to alter the structural proteins in vaccines that result from high temperature, organic and toxic solvents during production. Electrohydrodynamic processes, specifically electrospraying, could solve these challenges, as it also modulates antigen release and has a high loading efficiency. This review will highlight the mucosal immunity and biological basis of the gastrointestinal immune system, different oral vaccine delivery approaches, and the application of electrospraying in vaccines development. 相似文献
100.
Familial risk and heritability of intellectual disability: a population-based cohort study in Sweden