全文获取类型
收费全文 | 17837篇 |
免费 | 1279篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 127篇 |
儿科学 | 547篇 |
妇产科学 | 537篇 |
基础医学 | 2475篇 |
口腔科学 | 291篇 |
临床医学 | 2034篇 |
内科学 | 3368篇 |
皮肤病学 | 478篇 |
神经病学 | 1798篇 |
特种医学 | 492篇 |
外科学 | 1875篇 |
综合类 | 113篇 |
一般理论 | 7篇 |
预防医学 | 1953篇 |
眼科学 | 423篇 |
药学 | 1054篇 |
1篇 | |
中国医学 | 19篇 |
肿瘤学 | 1591篇 |
出版年
2024年 | 25篇 |
2023年 | 234篇 |
2022年 | 355篇 |
2021年 | 687篇 |
2020年 | 465篇 |
2019年 | 582篇 |
2018年 | 757篇 |
2017年 | 509篇 |
2016年 | 604篇 |
2015年 | 669篇 |
2014年 | 824篇 |
2013年 | 1109篇 |
2012年 | 1630篇 |
2011年 | 1601篇 |
2010年 | 811篇 |
2009年 | 759篇 |
2008年 | 1162篇 |
2007年 | 1175篇 |
2006年 | 1025篇 |
2005年 | 948篇 |
2004年 | 825篇 |
2003年 | 752篇 |
2002年 | 713篇 |
2001年 | 86篇 |
2000年 | 50篇 |
1999年 | 76篇 |
1998年 | 106篇 |
1997年 | 101篇 |
1996年 | 62篇 |
1995年 | 52篇 |
1994年 | 49篇 |
1993年 | 56篇 |
1992年 | 39篇 |
1991年 | 24篇 |
1990年 | 21篇 |
1989年 | 19篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 18篇 |
1985年 | 16篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 23篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1971年 | 8篇 |
1967年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Thompson Debra A.; Janecke Andreas R.; Lange Jessica; Feathers Kecia L.; Hubner Christian A.; McHenry Christina L.; Stockton David W.; Rammesmayer Gabriele; Lupski James R.; Antinolo Guillermo; Ayuso Carmen; Baiget Montserrat; Gouras Peter; Heckenlively John R.; den Hollander Anneke; Jacobson Samuel G.; Lewis Richard A.; Sieving Paul A.; Wissinger Bernd; Yzer Suzanne; Zrenner Eberhart; Utermann Gerd; Gal Andreas 《Human molecular genetics》2006,15(9):1559
Human Molecular Genetics 相似文献
32.
33.
34.
OBJECTIVE: The purpose of this study was to compare the preparation costs of two common methods used for neonatal red blood cell transfusion aliquots. METHODS: Three months of data from a Level 2 and Level 3 neonatal intensive care unit (NICU) were used to determine the comparative cost for red cell aliquot transfusions using an eight bag aliquot/transfer system or the syringe set system. Using leuko-poor red blood cell blood collected in Adsol and containing approximately 320 ml of red blood cells and supernatant solution, the average cost of neonatal transfusion aliquots was determined using the Charter Medical syringe set and the Charter Medical eight bag aliquot/transfer system. RESULTS: A total of 126 red blood cell transfusion aliquots were used over the three month period. The amount transfused with each aliquot ranged from 5.0 ml - 55.0 ml with an average of 24.0 ml per aliquot. The cost per aliquot using the eight aliquot/transfer set was calculated as $36.25 and the cost per aliquot using the syringe set cost was calculated as $30.71. Additional benefits observed with the syringe set included decreased blood waste. CONCLUSION: When comparing Charter Medical multiple aliquot bag sets and the Charter Medical syringe aliquot system to provide neonatal transfusions, the use of the syringe system decreased blood waste and proved more cost effective. 相似文献
35.
Kent Burnett Gail Ironson Charles Benight Christina Wynings Debra Greenwood Charles S. Carver Dean Cruess Andrew Baum Neil Schneiderman 《Journal of traumatic stress》1997,10(4):673-681
The purpose of this study was to develop and evaluate a measure of perceived disruption during rebuilding following a disaster. Two eight-item scales, which measured intensity of disruption during the entire repair phase (Intensity-RP) and intensity of disruption during the past month (Intensity-PM) were developed and administered to 135 survivors of Hurricane Andrew. At 9 to 12 months postdisaster, Intensity-RP and Intensity-PM were both significantly associated with scores on the Global Severity Index of the SCL-90-R, and with scores on the Impact of Event-Intrusion Scale; Intensity-PM alone was significantly associated with PTSD scores. Regression analyses indicated that each scale contributed significant unique variance in predicting mental health symptoms, even after controlling for relevant demographic and initial disaster exposure variables. 相似文献
36.
Carl Andrew Castro John B. Hogan Kimberly A. Benson Christina W. Shehata Michael R. Landauer 《Pharmacology, biochemistry, and behavior》1995,50(4):521-526
Experimental drugs and compounds that do not easily dissolve in water or saline are frequently combined with vehicles like solvents, detergents, or vegetable oils. Yet very little has been reported on the behavioral effects of vehicles. In this study, we assessed the effects of a vegetable oil (emulphor-620), two detergents (Tween-20 and Tween-80), and two solvents [dimethyl sulphoxide (DMSO) and ethanol] on the locomotor activity in CD2F1 male mice. Locomotor activity was monitored for 12 h after vehicle administration (IP). The concentrations for each vehicle were expressed as percent of vehicle in saline (v/v). Emulphor-620 did not affect locomotor activity at any concentration tested (2%, 4%, 8%, 16%, and 32%). Tween-20 significantly decreased locomotor activity at a concentration of 16% and Tween-80 at 32%. DMSO significantly decreased locomotor activity at concentrations of 32% and 64%. In contrast, ethanol produced a biphasic behavioral response: increased activity at a concentration of 16% and decreased activity at a concentration of 32%. These results will facilitate the selection and concentration of vehicles to be used in combination with experimental drugs or test agents. 相似文献
37.
38.
Frank S. Stay Albert Katko Christina M. Rohm Melissa A. Fix David P. Larsen 《Archives of environmental contamination and toxicology》1989,18(6):866-875
Comparisons were made among Leffler microcosms developed from four different natural communities and exposed to 0, 20, 100, 200, 500, 1,000, and 5,000 g/L atrazine, a commonly used herbicide. Atrazine reduced net primary productivity, pH, and net productivity/respiration ratios in all four microcosm communities. In three of the four communities, the lowest observed (P < 0.05) effect concentration (LOEL) was 100 g/L. In the fourth community the LOEL was 200 g/L atrazine.The sensitivity and accuracy of bioassays with four different microcosm communities were evaluated by comparing results with values reported for acute and chronic single species bioassays, other types of microcosms, and experimental ponds exposed to similar concentrations of atrazine. The ranges of sensitivity noted in these experiments were less than the range reported for single species bioassays using common test organisms and similar to those reported for other microcosms. The similarity between Leffler microcosm results and the responses reported for the experimental ponds suggests that the Leffler microcosms accurately reflected concentrations causing ecosystem level changes in the experimental ponds. 相似文献
39.
George V Dedoussis Demosthenes B Panagiotakos Nikoleta V Vidra Eirini Louizou Christina Chrysohoou Athanasios Germanos Yannis Mantas Savas Tokmakidis Christos Pitsavos Christodoulos Stefanadis 《Genetics in medicine》2005,7(6):411-416
PURPOSE: We investigated the association of a polymorphism within the promoter of TauNuF-alpha locus at the position -308 on the likelihood of having acute coronary syndromes (ACS) in Greek adults. METHODS: We studied demographic, lifestyle, and clinical information in 237 hospitalized patients (185 males) with a first event of an ACS and 237 matched by age and sex (controls) without any clinical evidence of coronary heart disease. Genotyping was performed by PCR-RFLP analysis. RESULTS: The genotype frequencies were in patients, 87% (n = 206), 12% (n = 29), and 1% (n = 2) for G/G, G/A, and A/A, and in controls, 96% (n = 227), 4% (n = 10), and 0% (n = 0) for G/G, G/A, and A/A, respectively (P = 0.04). After adjusting for age and sex, as well as various potential confounders, we observed that G/A or A/A genotypes were associated with 1.94-fold higher odds (95% CI 1.06 to 3.68) of ACS compared to G/G homozygotes. No gene to-gender or to-clinical syndrome interactions were observed. Further subgroup analysis showed that the distribution of TNF-alpha -308G>A polymorphism was associated with the presence of family history of CHD in patients, but not in controls. In particular, in G/A and A/A patients 17.2% reported family history of CHD, whereas in G/G patients, 34.5% reported family history (P = 0.036). CONCLUSIONS: Our findings may state a hypothesis of an association between the -308G>A TNF-alpha polymorphism the development of ACS and the presence of family history of CHD, in Greece. 相似文献
40.
Bartholdy C Stryhn A Hansen NJ Buus S Thomsen AR 《European journal of immunology》2003,33(7):1941-1948
DNA vaccination is an efficient way to induce CD8+ T cell memory, but it is still unclear to what extent such memory responses afford protection in vivo. To study this, we induced CD8+ memory responses directed towards defined viral epitopes, using DNA vaccines encoding immunodominant MHC class I-restricted epitopes of lymphocytic choriomeningitis virus covalently linked to beta2-microglobulin. This vaccine construct primed for a stronger recall response than did a more conventional minigene construct. Despite this, vaccinated mice were only protected against systemic infection whereas protection against the consequences of peripheral challenge was limited. Phenotypic analysis revealed that DNA vaccine-primed CD8+ T cells in uninfected mice differed from virus-primed CD8+ T cells particularly regarding expression of very-late antigen (VLA)-4, an adhesion molecule important for targeting T cells to inflammatory sites. Thus, our DNA vaccine induces a long-lived memory CD8+ T cell population that provides efficient protection against high-dose systemic infection. However, viral replication in solid non-lymphoid organs is not curtailed sufficiently fast to prevent significant virus-induced inflammation. Our results suggest that this is due to qualitative limitations of the primed CD8+ T cells. 相似文献