全文获取类型
收费全文 | 24828篇 |
免费 | 1250篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 440篇 |
儿科学 | 519篇 |
妇产科学 | 415篇 |
基础医学 | 3365篇 |
口腔科学 | 2417篇 |
临床医学 | 1654篇 |
内科学 | 5526篇 |
皮肤病学 | 474篇 |
神经病学 | 2066篇 |
特种医学 | 490篇 |
外科学 | 3127篇 |
综合类 | 76篇 |
一般理论 | 9篇 |
预防医学 | 2463篇 |
眼科学 | 471篇 |
药学 | 1523篇 |
中国医学 | 173篇 |
肿瘤学 | 952篇 |
出版年
2024年 | 27篇 |
2023年 | 217篇 |
2022年 | 477篇 |
2021年 | 770篇 |
2020年 | 519篇 |
2019年 | 635篇 |
2018年 | 976篇 |
2017年 | 619篇 |
2016年 | 680篇 |
2015年 | 825篇 |
2014年 | 1047篇 |
2013年 | 1316篇 |
2012年 | 2084篇 |
2011年 | 2448篇 |
2010年 | 1221篇 |
2009年 | 870篇 |
2008年 | 1718篇 |
2007年 | 1828篇 |
2006年 | 1516篇 |
2005年 | 1413篇 |
2004年 | 1221篇 |
2003年 | 1052篇 |
2002年 | 912篇 |
2001年 | 236篇 |
2000年 | 221篇 |
1999年 | 174篇 |
1998年 | 79篇 |
1997年 | 61篇 |
1996年 | 59篇 |
1995年 | 55篇 |
1994年 | 41篇 |
1993年 | 39篇 |
1992年 | 67篇 |
1991年 | 87篇 |
1990年 | 56篇 |
1989年 | 51篇 |
1988年 | 33篇 |
1987年 | 43篇 |
1986年 | 34篇 |
1985年 | 35篇 |
1984年 | 32篇 |
1983年 | 33篇 |
1982年 | 25篇 |
1980年 | 25篇 |
1979年 | 23篇 |
1978年 | 26篇 |
1977年 | 18篇 |
1974年 | 17篇 |
1971年 | 22篇 |
1969年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Adilson Cunha Ferreira Edward Araujo Júnior Wellington P. Martins João Francisco Jordão Antônio Hélio Oliani Simon E. Meagher 《The journal of maternal-fetal & neonatal medicine》2015,28(14):1706-1710
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality. 相似文献
4.
José A. Lorente Pablo Cardinal-Fernández Diego Muñoz Fernando Frutos-Vivar Arnaud W. Thille Carlos Jaramillo Aida Ballén-Barragán José M. Rodríguez Oscar Peñuelas Guillermo Ortiz José Blanco Bruno Valle Pinheiro Nicolás Nin María del Carmen Marin Andrés Esteban Taylor B. Thompson 《Intensive care medicine》2015,41(11):1921-1930
5.
6.
Rubens Souza de OLIVEIRA Lanna Jamile Corrêa da COSTA Fernanda Atanaena Gon?alves de ANDRADE Wilson UIEDA Luzia Fátima Alves MARTORELLI Ana Paula de Arruda Geraldes KATAOKA Elizabeth Salbé Travassos da ROSA Pedro Fernando da Costa VASCONCELOS Armando de Souza PEREIRA Ant?nio Ismael Barros do CARMO Marcus Emanuel Barroncas FERNANDES 《Revista do Instituto de Medicina Tropical de S?o Paulo》2015,57(6):497-503
The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005,
in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a
priority area for studies on this zoonosis. Given this, the present study provides
data on this phenomenon in an urban context, in order to assess the possible
circulation of the classic rabies virus (RABV) among bat species in Capanema, a town
in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and
dry seasons. Samples of brain tissue and blood were collected for virological and
serological survey, respectively. None of the 153 brain tissue samples analyzed
tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum
samples analyzed were seropositive. Artibeus planirostris was the most common
species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31
52.60%). Statistically, equal proportions of seropositive results were obtained in
the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly
higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95%
CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested
positive for infection, the high proportion of seropositive specimens indicates that
RABV may be widespread in this urban area. 相似文献
7.
Mariana Spitz Alexandre Aluízio Costa Machado Rodrigo do Carmo Carvalho Fernanda Martins Maia Monica Santoro Haddad Dagoberto Calegaro Milberto Scaff Egberto Reis Barbosa 《Movement disorders》2006,21(9):1520-1522
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception. 相似文献
8.
9.
10.
Luiz Fernando Tomazinho Mario J Avila-Campos 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,103(2):285-288
Black-pigmented anaerobic rods such as Prevotella spp. and Porphyromonas spp. are involved in the etiology and perpetuation of endodontic infections. The aim of this study was to evaluate the prevalence of these species in chronic endodontic infections by using culture and polymerase chain reaction (PCR) techniques. Samples of 100 patients with root canals displaying chronic endodontic infections were obtained by sterilized paper points. Bacterial identification was performed by using culture and PCR techniques. By culture, in 33% of the samples, P. intermedia-P. nigrescens (75.8%), P. gingivalis (27.3%), and P. endodontalis (9.1%) were identified, and by PCR 60% of the samples harbored P. nigrescens (43.3%), P. gingivalis (43.3%), P. intermedia (31.7%), and P. endodontalis (23.3%). The presence of these black-pigmented anaerobic rods alone or in association in chronic endodontic infections seems to be frequent. PCR is a very sensitive technique for detecting DNA from bacterial cells. Culturing is only able to reveal living bacteria and is less sensitive for the identification of low numbers of bacterial cells. 相似文献