全文获取类型
收费全文 | 25938篇 |
免费 | 1259篇 |
国内免费 | 181篇 |
专业分类
耳鼻咽喉 | 200篇 |
儿科学 | 534篇 |
妇产科学 | 439篇 |
基础医学 | 2833篇 |
口腔科学 | 635篇 |
临床医学 | 2068篇 |
内科学 | 6795篇 |
皮肤病学 | 500篇 |
神经病学 | 2978篇 |
特种医学 | 784篇 |
外科学 | 3894篇 |
综合类 | 43篇 |
一般理论 | 5篇 |
预防医学 | 1101篇 |
眼科学 | 451篇 |
药学 | 1462篇 |
中国医学 | 31篇 |
肿瘤学 | 2625篇 |
出版年
2024年 | 54篇 |
2023年 | 173篇 |
2022年 | 396篇 |
2021年 | 757篇 |
2020年 | 450篇 |
2019年 | 622篇 |
2018年 | 703篇 |
2017年 | 552篇 |
2016年 | 623篇 |
2015年 | 695篇 |
2014年 | 1017篇 |
2013年 | 1277篇 |
2012年 | 2010篇 |
2011年 | 1998篇 |
2010年 | 1156篇 |
2009年 | 1069篇 |
2008年 | 1749篇 |
2007年 | 1809篇 |
2006年 | 1674篇 |
2005年 | 1650篇 |
2004年 | 1638篇 |
2003年 | 1356篇 |
2002年 | 1327篇 |
2001年 | 193篇 |
2000年 | 121篇 |
1999年 | 151篇 |
1998年 | 250篇 |
1997年 | 212篇 |
1996年 | 196篇 |
1995年 | 171篇 |
1994年 | 132篇 |
1993年 | 131篇 |
1992年 | 119篇 |
1991年 | 91篇 |
1990年 | 90篇 |
1989年 | 68篇 |
1988年 | 68篇 |
1987年 | 64篇 |
1986年 | 57篇 |
1985年 | 57篇 |
1984年 | 79篇 |
1983年 | 44篇 |
1982年 | 45篇 |
1981年 | 43篇 |
1980年 | 33篇 |
1979年 | 20篇 |
1978年 | 16篇 |
1977年 | 31篇 |
1976年 | 19篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
122.
Paolo De Pasquale Erasmo Rubino Daniele Borzelli Matteo Peditto Enrico Nastro Siniscalchi Francesco Saverio De Ponte Giacomo Oteri Andrea dAvella 《Materials》2022,15(11)
Assessing maximum voluntary bite force is important to characterize the functional state of the masticatory system. Due to several factors affecting the estimation of the maximum bite force, a unique solution combining desirable features such as reliability, accuracy, precision, usability, and comfort is not available. The aim of the present study was to develop a low-cost bite force measurement device allowing for subject-specific customization, comfortable bite force expression, and reliable force estimation over time. The device was realized using an inexpensive load cell, two 3D printed ergonomic forks hosting reusable subject-specific silicone molds, a read-out system based on a low-cost microcontroller, and a wireless link to a personal computer. A simple model was used to estimate bite force taking into account individual morphology and device placement in the mouth. Measurement reliability, accuracy, and precision were assessed on a calibration dataset. A validation procedure on healthy participants was performed to assess the repeatability of the measurements over multiple repetitions and sessions. A 2% precision and 2% accuracy were achieved on measurements of forces in the physiological range of adult bite forces. Multiple recordings on healthy participants demonstrated good repeatability (coefficient of variation 11%) with no significant effect of repetition and session. The novel device provides an affordable and reliable solution for assessing maximum bite force that can be easily used to perform clinical evaluations in single sessions or in longitudinal studies. 相似文献
123.
124.
125.
Vanessa Palmas Silvia Pisanu Veronica Madau Emanuela Casula Andrea Deledda Roberto Cusano Paolo Uva Andrea Loviselli Fernanda Velluzzi Aldo Manzin 《Nutrients》2022,14(12)
This study was aimed at characterizing the gut microbiota (GM) and its functional profile in two groups of Sardinian subjects with a long healthy life expectancy, overall named Long-Lived Subjects (LLS) [17 centenarians (CENT) and 29 nonagenarians (NON)] by comparing them to 46 healthy younger controls (CTLs). In addition, the contribution of genetics and environmental factors to the GM phenotype was assessed by comparing a subgroup of seven centenarian parents (CPAR) with a paired cohort of centenarians’ offspring (COFF). The analysis was performed through Next Generation Sequencing (NGS) of the V3 and V4 hypervariable region of the 16S rRNA gene on the MiSeq Illumina platform. The Verrucomicrobia phylum was identified as the main biomarker in CENT, together with its members Verrucomicrobiaceae, Akkermansia and Akkermansia muciniphila. In NON, the strongest associations concern Actinobacteria phylum, Bifidobacteriaceae and Bifidobacterium, while in CTLs were related to the Bacteroidetes phylum, Bacteroidaceae, Bacteroides and Bacteroides spp. Intestinal microbiota of CPAR and COFF did not differ significantly from each other. Significant correlations between bacterial taxa and clinical and lifestyle data, especially with Mediterranean diet adherence, were observed. We observed a harmonically balanced intestinal community structure in which the increase in taxa associated with intestinal health would limit and counteract the action of potentially pathogenic bacterial species in centenarians. The GM of long-lived individuals showed an intrinsic ability to adapt to changing environmental conditions, as confirmed by functional analysis. The GM analysis of centenarians’ offspring suggest that genetics and environmental factors act synergistically as a multifactorial cause in the modulation of GM towards a phenotype similar to that of centenarians, although these findings need to be confirmed by larger study cohorts and by prospective studies. 相似文献
126.
Federico Belladelli Luca Boeri Paolo Capogrosso Walter Cazzaniga Eugenio Ventimiglia Luigi Candela Edoardo Pozzi Andrea Baudo Massimo Alfano Costantino Abbate Francesco Montorsi Andrea Salonia 《Asian journal of andrology》2021,(5):456-461
Substances of abuse(SoA),as well as smoking and alcohol consumption,are well known for their impact on male fertility status,erectile function,and ejaculation.W... 相似文献
127.
Reinaldo Dal Bello Justine Pasanisi Romane Joudinaud Matthieu Duchmann Bryann Pardieu Paolo Ayaka Giuseppe Di Feo Gaetano Sodaro Clmentine Chauvel Rathana Kim Loic Vasseur Laureen Chat Frank Ling Kim Pacchiardi Camille Vaganay Jeannig Berrou Chaima Benaksas Nicolas Boissel Thorsten Braun Claude Preudhomme Herv Dombret Emmanuel Raffoux Nina Fenouille Emmanuelle Clappier Lionel Ads Alexandre Puissant Raphael Itzykson 《Blood cancer journal》2022,12(6)
128.
Leonardo Urbano Davide Dalmazzo Pier Paolo Riviera Orazio Baglieri Ezio Santagata 《Materials》2022,15(11)
This paper presents the results of an experimental investigation which was carried out with the purpose of assessing the performance-related properties of an emulsion-based cold-recycled mixture to be employed as a sustainable solution for the surface finishing of unpaved rural roads. This mixture contained significant quantities of recycled components (reclaimed asphalt and mineral sludge), and its composition was fine-tuned by following an innovative mix design procedure. Properties of these mixtures were studied by means of laboratory tests which considered key parameters, such as flowability, indirect tensile stiffness modulus, indirect tensile strength, moisture susceptibility and resistance to permanent deformation. It was found that, by means of the proposed mix design procedure, optimal dosages of the recycled components can be identified, thereby ensuring the achievement of the desired properties in terms of high workability and adequate stiffness and strength. 相似文献
129.
Simona Sacco Faisal Mohammad Amin Messoud Ashina Lars Bendtsen Christina I. Deligianni Raquel Gil-Gouveia Zaza Katsarava Antoinette MaassenVanDenBrink Paolo Martelletti Dimos-Dimitrios Mitsikostas Raffaele Ornello Uwe Reuter Margarita Sanchez-del-Rio Alexandra J. Sinclair Gisela Terwindt Derya Uluduz Jan Versijpt Christian Lampl 《The journal of headache and pain》2022,23(1)
BackgroundA previous European Headache Federation (EHF) guideline addressed the use of monoclonal antibodies targeting the calcitonin gene-related peptide (CGRP) pathway to prevent migraine. Since then, randomized controlled trials (RCTs) and real-world evidence have expanded the evidence and knowledge for those treatments. Therefore, the EHF panel decided to provide an updated guideline on the use of those treatments.MethodsThe guideline was developed following the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed a systematic review and an analysis of the literature, assessed the quality of the available evidence, and wrote recommendations. Where the GRADE approach was not applicable, expert opinion was provided.ResultsWe found moderate to high quality of evidence to recommend eptinezumab, erenumab, fremanezumab, and galcanezumab in individuals with episodic and chronic migraine. For several important clinical questions, we found not enough evidence to provide evidence-based recommendations and guidance relied on experts’ opinion. Nevertheless, we provided updated suggestions regarding the long-term management of those treatments and their place with respect to the other migraine preventatives.ConclusionMonoclonal antibodies targeting the CGRP pathway are recommended for migraine prevention as they are effective and safe also in the long-term.Supplementary InformationThe online version contains supplementary material available at 10.1186/s10194-022-01431-x. 相似文献
130.
Roberto Lorusso Samuel Heuts Federica Jiritano Roberto Scrofani Carlo Antona Guglielmo Actis Dato Paolo Centofanti Sandro Ferrarese Matteo Matteucci Antonio Miceli Mattia Glauber Enrico Vizzardi Sandro Sponga Igor Vendramin Andrea Garatti Carlo de Vincentis Michele De Bonis Silvia Ajello Giovanni Troise Margherita Dalla Tomba Filiberto Serraino 《Interactive Cardiovascular and Thoracic Surgery》2022,35(1)
Open in a separate window OBJECTIVESAlthough the intra-aortic balloon pump (IABP) has been the most widely adopted temporary mechanical support device in cardiac surgical patients, its use has declined. The current study aimed to evaluate the occurrence and predictors of early mortality and complication rates in contemporary cardiac surgery patients supported by an IABP.METHODSA multicentre, retrospective analysis was performed of all consecutive cardiac surgical patients receiving perioperative balloon pump support in 8 centres between January 2010 to December 2019. The primary outcome was early mortality, and secondary outcomes were balloon-associated complications. A multivariable binary logistic regression model was applied to evaluate predictors of the primary outcome.RESULTSThe study cohort consisted of 2615 consecutive patients. The median age was 68 years [25th percentile 61, 75th percentile 75 years], with the majority being male (76.9%), and a mean calculated 30-day mortality risk of 10.0%. Early mortality was 12.7% (n = 333), due to cardiac causes (n = 266), neurological causes (=22), balloon-related causes (n = 5) and other causes (n = 40). A composite end point of all vascular complications occurred in 7.2% of patients, and leg ischaemia was observed in 1.3% of patients. The most important predictors of early mortality were peripheral vascular disease [odds ratio (OR) 1.63], postoperative dialysis requirement (OR 10.40) and vascular complications (OR 2.57).CONCLUSIONSThe use of the perioperative IABP proved to be safe and demonstrated relatively low complication rates, particularly for leg ischaemia. As such, we believe that specialists should not be held back to use this widely available treatment in high-risk cardiac surgical patients when indicated. 相似文献