全文获取类型
收费全文 | 8985篇 |
免费 | 545篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 171篇 |
妇产科学 | 150篇 |
基础医学 | 1336篇 |
口腔科学 | 1160篇 |
临床医学 | 645篇 |
内科学 | 1761篇 |
皮肤病学 | 340篇 |
神经病学 | 789篇 |
特种医学 | 159篇 |
外科学 | 893篇 |
综合类 | 33篇 |
一般理论 | 3篇 |
预防医学 | 955篇 |
眼科学 | 144篇 |
药学 | 564篇 |
中国医学 | 83篇 |
肿瘤学 | 244篇 |
出版年
2023年 | 78篇 |
2022年 | 94篇 |
2021年 | 286篇 |
2020年 | 261篇 |
2019年 | 324篇 |
2018年 | 353篇 |
2017年 | 258篇 |
2016年 | 238篇 |
2015年 | 357篇 |
2014年 | 446篇 |
2013年 | 530篇 |
2012年 | 800篇 |
2011年 | 799篇 |
2010年 | 434篇 |
2009年 | 337篇 |
2008年 | 535篇 |
2007年 | 497篇 |
2006年 | 477篇 |
2005年 | 406篇 |
2004年 | 315篇 |
2003年 | 276篇 |
2002年 | 255篇 |
2001年 | 164篇 |
2000年 | 131篇 |
1999年 | 124篇 |
1998年 | 52篇 |
1997年 | 38篇 |
1996年 | 31篇 |
1995年 | 29篇 |
1994年 | 33篇 |
1993年 | 30篇 |
1992年 | 55篇 |
1991年 | 49篇 |
1990年 | 41篇 |
1989年 | 38篇 |
1988年 | 31篇 |
1987年 | 32篇 |
1986年 | 19篇 |
1985年 | 27篇 |
1984年 | 30篇 |
1983年 | 17篇 |
1982年 | 16篇 |
1980年 | 20篇 |
1975年 | 20篇 |
1973年 | 19篇 |
1972年 | 12篇 |
1970年 | 13篇 |
1968年 | 12篇 |
1967年 | 12篇 |
1966年 | 14篇 |
排序方式: 共有9568条查询结果,搜索用时 15 毫秒
1.
Ekstrand Kim R. Cordeschi Thais Abreu-Placeres Ninoska 《Clinical oral investigations》2022,26(3):2597-2605
Clinical Oral Investigations - To examine the relationship between the ICCMS? (International Caries Classification and Managing System) features of root caries lesions and the underlying... 相似文献
2.
Saidy Vásconez Noguera Evelyn Patrícia Sánchez Espinoza Marina Farrel Côrtes Izabel Cristina Vilela Oshiro Fernanda de Sousa Spadão Laura Maria Brasileiro Brandão Ana Natiele da Silva Barros Sibeli Costa Bianca Leal de Almeida Paula Gemignani Soriano Alessandra Grassi Salles Mirian Elizabete Marques Escorcio Cristina Madeira Barretti Fernanda Spadotto Baptista Glaura Souza Alvarenga Igor Marinho Leila Suemi Harima Letaif Ho Ye Li Silvia Figueiredo Costa 《American journal of infection control》2021,49(4):512-515
3.
4.
Dominski Fábio Hech Serafim Thiago Teixeira Siqueira Thais Cristina Andrade Alexandro 《Sport Sciences for Health》2021,17(1):21-41
Sport Sciences for Health - This study aimed to review the existing literature concerning the psychological variables of CrossFit participants. This review followed the PRISMA guidelines and was... 相似文献
5.
Letícia Queiroz Mauad Paulo Victor Teixeira Doriguêtto Daniela de Almeida Karolina Aparecida Castilho Fardim Alessiana Helena Machado Karina Lopes Devito 《Dento maxillo facial radiology》2021,50(3)
Objectives:To evaluate, in an in vitro study, the quantity of artefacts generated by two different restorative materials, and to determine the diagnostic accuracy of cone beam CT (CBCT) scans and periapical radiographs in identifying gaps in prosthetic crowns.Methods:A total of 30 teeth restored with metal-ceramic (n = 15) and all-ceramic (n = 15) crowns, properly adapted and with 0.30- and 0.50 mm gaps, underwent CBCT exams (with voxel sizes of 0.25 and 0.30 mm) and periapical radiographs. The artefacts generated by two different crowns were quantified and compared by the Mann–Whitney test. In addition, five examiners evaluated the presence or absence of gaps in periapical radiographs and CBCT images. The accuracy of tests was determined by the area under the receiver operatring characteristic curve and these values were compared by using the Kruskal–Wallis test.Results:There was no significant difference in artefact values between the different restorative materials and the different resolutions of CBCT images. Regarding the accuracy of the tests evaluated, periapical radiography and CBCT with voxel size 0.25 mm showed the best performance for smaller gaps (0.30 mm). For larger gaps (0.50 mm), all exams tested showed the same performance.Conclusions:Periapical radiography was still the most cost-beneficial method for the diagnosis of maladaptation in dental restorations. CBCT exams did not improve accuracy in detecting gaps in prosthetic crowns. 相似文献
6.
Amanda Souza Setti Daniela Paes de Almeida Ferreira Braga Livia Vingris Assumpto Iaconelli Jr. Edson Borges Jr. 《Andrologia》2021,53(11):e14211
The objective of this study was to investigate the impact of male age, semen quality and days of ejaculatory abstinence on embryo morphokinetics. A total of 1,220 zygotes obtained from 139 couples in a private in vitro fertilisation centre were analysed. The timing of specific events from the point of insemination, such as timings to pronuclei appearance and fading, to two, three, four, five, six, seven and eight cells and to blastulation were recorded. Multivariate linear regression analysis was used to evaluate the influence of paternal factors on embryo morphokinetic events. Paternal age was positively correlated with delayed cell cleavage and blastulation, and negatively associated with implantation rate, and clinical pregnancy and live–birth chances. The ejaculatory abstinence was inversely correlated with the implantation rate. Inverse relationships were observed between semen parameters (sperm count, progressive sperm motility, total motile sperm count and morphology) and the timing of specific events during embryo development. Sperm morphology was also positively associated with implantation rate and pregnancy and live–birth chances. Increased paternal age and ejaculatory abstinence, and poor semen quality correlate with delayed cell cleavage and blastulation and negatively impact intracytoplasmic sperm injection outcomes. 相似文献
7.
Albuquerque Lucas Alverne F. Almeida Joo Paulo de Macdo Filho Leonardo Jos Monteiro Joaquim Andrei F. Duffau Hugues 《Neurosurgical review》2021,44(3):1371-1389
Neurosurgical Review - There is a lack of class I evidence concerning the impact of surgery in the treatment of diffuse low-grade glioma; the early maximal resection with preservation of eloquent... 相似文献
8.
Accuracy of CAD-CAM systems for removable partial denture framework fabrication: A systematic review
Ana Larisse Carneiro Pereira Annie Karoline Bezerra de Medeiros Kaiza de Sousa Santos Érika Oliveira de Almeida Gustavo Augusto Seabra Barbosa Adriana da Fonte Porto Carreiro 《The Journal of prosthetic dentistry》2021,125(2):241-248
Statement of problemRemovable partial dentures (RPDs) are traditionally made by casting, a complex, error-prone, and time-consuming process. Computer-aided design and computer-aided manufacturing (CAD-CAM) RPD systems may simplify the clinical steps and minimize errors; however, the accuracy of CAD-CAM RPD systems is unclear.PurposeThe purpose of this systematic review was to determine whether CAD-CAM systems are accurate for the manufacturing of RPD frameworks.Material and methodsA literature search was conducted through Medline-PubMed, Scopus, Lilacs, Web of Science, and Cochrane Library databases using specific keywords for articles published up to November 2019. Three reviewers obtained data and compared the results. All studies evaluated the framework accuracy or fit of prostheses fabricated with conventional and digital techniques.ResultsA total of 7 articles, 2 clinical studies, and 5 in vitro studies that complied with the inclusion criteria were evaluated. One in vitro study compared indirect (extraoral) and direct (intraoral) scanning for partially edentulous ridges and shows that digital scans were better than conventional impressions in terms of trueness. In the other studies included, although the frameworks analyzed had clinically acceptable discrepancies (<311 μm), the material influenced the fit. Polyetheretherketone (PEEK) showed better fit than traditional metal cast RPDs. Co-Cr alloy RPDs produced by rapid prototyping exhibited the highest discrepancies when produced by sintering laser melting.ConclusionsThe results show that the digital technique for RPD frameworks is accurate. In the studies included, the analyzed frameworks had clinically acceptable gaps, but the results were heterogeneous among studies because the articles used different measurement methods with small sample sizes. Few studies discussed the long-term clinical performance. The digital technique for RPD frameworks was accurate because the misfits and mismatches found in in vitro and clinical studies were within the acceptable clinical limit for RPDs. 相似文献
9.