全文获取类型
收费全文 | 309298篇 |
免费 | 15735篇 |
国内免费 | 898篇 |
专业分类
耳鼻咽喉 | 4543篇 |
儿科学 | 9475篇 |
妇产科学 | 6912篇 |
基础医学 | 42127篇 |
口腔科学 | 11772篇 |
临床医学 | 21313篇 |
内科学 | 71469篇 |
皮肤病学 | 8784篇 |
神经病学 | 25687篇 |
特种医学 | 8548篇 |
外国民族医学 | 28篇 |
外科学 | 37823篇 |
综合类 | 2417篇 |
现状与发展 | 1篇 |
一般理论 | 100篇 |
预防医学 | 31143篇 |
眼科学 | 6347篇 |
药学 | 20392篇 |
中国医学 | 1465篇 |
肿瘤学 | 15585篇 |
出版年
2023年 | 1715篇 |
2022年 | 3387篇 |
2021年 | 7265篇 |
2020年 | 4175篇 |
2019年 | 6823篇 |
2018年 | 9724篇 |
2017年 | 6489篇 |
2016年 | 6145篇 |
2015年 | 6998篇 |
2014年 | 9517篇 |
2013年 | 12881篇 |
2012年 | 20122篇 |
2011年 | 21220篇 |
2010年 | 11006篇 |
2009年 | 9380篇 |
2008年 | 16460篇 |
2007年 | 17500篇 |
2006年 | 16339篇 |
2005年 | 16637篇 |
2004年 | 15387篇 |
2003年 | 14171篇 |
2002年 | 11857篇 |
2001年 | 9092篇 |
2000年 | 9548篇 |
1999年 | 7962篇 |
1998年 | 2350篇 |
1997年 | 1914篇 |
1996年 | 1787篇 |
1995年 | 1541篇 |
1994年 | 1448篇 |
1993年 | 1275篇 |
1992年 | 4055篇 |
1991年 | 3754篇 |
1990年 | 3407篇 |
1989年 | 3203篇 |
1988年 | 2902篇 |
1987年 | 2661篇 |
1986年 | 2548篇 |
1985年 | 2346篇 |
1984年 | 1703篇 |
1983年 | 1399篇 |
1982年 | 815篇 |
1979年 | 1353篇 |
1978年 | 901篇 |
1975年 | 834篇 |
1974年 | 932篇 |
1973年 | 950篇 |
1972年 | 805篇 |
1970年 | 795篇 |
1969年 | 808篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Objectives
For individuals not on antiretroviral therapy, the risk of heterosexual transmission of HIV appears negligible when blood plasma (BP) viral loads are <1500 HIV‐1 RNA copies/mL. It is not clear whether this observation can be extrapolated to individuals on highly active antiretroviral therapy (HAART). Because of differential tissue penetration, antiretroviral drug concentrations may be sufficient to maintain an undetectable viral load in the BP yet not achieve adequate levels to suppress HIV in the genital tract. Therefore, we wanted to correlate HIV viral loads and drug concentrations in semen plasma (SP) and BP.Methods
Thirty‐three men were included. All were on combination antiretroviral therapy with an undetectable BP viral load for at least 1 year. Blood and semen samples were collected within 2 h of each other and tested for HIV RNA by the NucliSens QT (bioMerieux, St Laurent, QC, Canada) method; drug concentrations were determined by liquid chromatography tandem mass spectrometry.Results
Two of the 33 patients (6.1%) with BP viral loads below detection had time‐matched HIV viral loads in SP ≥700 copies/mL. Both patients were on efavirenz, the SP concentrations of which were ≤10% of the levels in BP and well below the minimal therapeutic drug monitoring target concentration required to suppress HIV.Conclusions
Because, at least in part, of poor drug penetration into the genital tract, an undetectable HIV viral load in the BP does not guarantee an undetectable viral load in semen. In view of this, caution should be taken in concluding that patients on HAART with suppressed viraemia are sexually non‐infectious. 相似文献82.
Marieke Peeters Ludo Verhoeven Jan de Moor Hans van Balkom 《Research in developmental disabilities》2009,30(4):712-726
The goal of this longitudinal study was to investigate the precursors of early reading development in 52 children with cerebral palsy at kindergarten level in comparison to 65 children without disabilities. Word Decoding was measured to investigate early reading skills, while Phonological Awareness, Phonological Short-term Memory (STM), Speech Perception, Speech Production and Nonverbal Reasoning were considered reading precursors. Children with cerebral palsy lag behind on all reading precursors at the beginning of the second year of kindergarten. For the children without disabilities, early reading skills in Grade 1 were best predicted by Phonological Awareness and Phonological STM while Speech Production was the most important predictor of early reading success for the children with cerebral palsy, followed by Phonological Awareness and Speech Perception. Furthermore, for children with cerebral palsy, Speech Production appears to dominate reading development, as Speech Production measured at the beginning of the second year of kindergarten was strongly predictive of all other reading precursors measured at the end of the second year of kindergarten. The results of this study reveal that children with cerebral palsy with additional speech impairments are at risk for limited literacy development. Clinical implications are discussed. 相似文献
83.
Drug-resistance in Streptococcus pneumoniae isolates among Spanish middle aged and older adults with community-acquired pneumonia 总被引:1,自引:0,他引:1
Angel Vila-Corcoles Ferran Bejarano-Romero Elisabeth Salsench Olga Ochoa-Gondar Cinta de Diego Frederic Gomez-Bertomeu Xavier Raga-Luria Xavier Cliville-Guasch Victoria Arija 《BMC infectious diseases》2009,9(1):36
Background
Pneumococcal diseases remain a major cause of morbidity and mortality worldwide. Updated data on drug-resistance from different populations may be important to recognize changes in disease patterns. This study assessed current levels of penicilin resistance among Streptococcus Pneumoniae causing pneumonia in Spanish middle age and older adults. 相似文献84.
85.
86.
87.
88.
Aneurisma de aorta abdominal infrarrenal en asociación con riñón en herradura: aportación de un caso
Nerea Senarriaga Ruiz de la Illa Reyes Vega Manrique Isabel Lacasa Viscasillas Iñaki Iriarte Soldevilla Miguel Unda Urzaiz 《Actas urologicas espa?olas》2009,33(10):1141-1144
We review the association between surgically resolvable aortic disease and horseshoe kidney with a discussion of diagnostic problems and therapeutic options.Male patient 81 years of age with horseshoe kidney and an abdominal aortic aneurysm that was discovered by chance in an abdominal ultrasound during a check-up for his prostate condition.A retroperitoneal approach was used in order to resect the aneurysm and perform an aorto-aortic bypass with no complications occurring. Two years after the diagnosis, the patient is still asymptomatic from a vascular point of view.The co-presence of horseshoe kidney and aortic disease needing surgical correction is infrequent, but it significantly increases the technical complexity of aortic reconstruction. A literature review is included. 相似文献
89.
90.