全文获取类型
收费全文 | 2211篇 |
免费 | 248篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 91篇 |
妇产科学 | 33篇 |
基础医学 | 323篇 |
口腔科学 | 48篇 |
临床医学 | 343篇 |
内科学 | 372篇 |
皮肤病学 | 23篇 |
神经病学 | 169篇 |
特种医学 | 114篇 |
外科学 | 293篇 |
综合类 | 68篇 |
一般理论 | 2篇 |
预防医学 | 255篇 |
眼科学 | 48篇 |
药学 | 165篇 |
中国医学 | 26篇 |
肿瘤学 | 80篇 |
出版年
2023年 | 15篇 |
2021年 | 37篇 |
2020年 | 27篇 |
2019年 | 28篇 |
2018年 | 32篇 |
2017年 | 30篇 |
2016年 | 30篇 |
2015年 | 39篇 |
2014年 | 48篇 |
2013年 | 67篇 |
2012年 | 126篇 |
2011年 | 105篇 |
2010年 | 61篇 |
2009年 | 63篇 |
2008年 | 104篇 |
2007年 | 122篇 |
2006年 | 116篇 |
2005年 | 77篇 |
2004年 | 80篇 |
2003年 | 76篇 |
2002年 | 106篇 |
2001年 | 93篇 |
2000年 | 80篇 |
1999年 | 58篇 |
1998年 | 51篇 |
1997年 | 37篇 |
1996年 | 42篇 |
1995年 | 22篇 |
1994年 | 35篇 |
1993年 | 32篇 |
1992年 | 55篇 |
1991年 | 43篇 |
1990年 | 38篇 |
1989年 | 36篇 |
1988年 | 32篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 40篇 |
1984年 | 22篇 |
1983年 | 26篇 |
1982年 | 13篇 |
1981年 | 17篇 |
1979年 | 29篇 |
1977年 | 14篇 |
1976年 | 17篇 |
1975年 | 19篇 |
1974年 | 23篇 |
1973年 | 27篇 |
1972年 | 18篇 |
1971年 | 17篇 |
排序方式: 共有2468条查询结果,搜索用时 151 毫秒
61.
Rationale
The active component of cannabis, delta-9 tetrahydrocannabinol (THC), has a long half-life and widespread neurocognitive effects. There are inconsistent reports of neurocognitive deficits in adults and adolescents with cannabis use disorders (CUD), particularly after a period of abstinence.Objectives
This study aims to examine neurocognitive measures (IQ, academic achievement, attention, memory, executive functions) in abstinent adolescents with CUD, while controlling for demographic, psychopathology, and poly-substance confounders.Methods
We investigated neurocognitive performance in three groups: adolescents with CUD after successful first treatment and in full remission (n?=?33); controls with psychiatric disorders without substance use disorder history (n?=?37); and healthy adolescents (n?=?43).Results
Adolescents with psychiatric disorders, regardless of CUD status, performed significantly worse than the healthy adolescents in academic achievement. No group differences were seen in IQ, attention, memory, or executive functions. Lower academic achievement was positively associated with younger age of CUD onset, regular cannabis use, and maximum daily use. In the CUD group, lifetime nicotine use episodes were negatively associated with IQ. Lower overall neurocognitive function was associated with younger age of onset of regular cannabis use and relapse within the 1 year follow-up.Conclusions
Verifiably, abstinent adolescents with CUD history did not differ from the two comparison groups, suggesting that previously reported neurocognitive deficits may be related to other factors, including residual drug effects, preexisting cognitive deficits, concurrent use of other substances (e.g., nicotine), or psychopathology. Adolescents with CUD may not be vulnerable to THC neuropsychological deficits once they achieve remission from all drugs for at least 30 days. 相似文献62.
63.
65.
66.
67.
68.
Giorgio SilvaSantana Juliet Cunha Bax Dbora Cristina Silva Fernandes Daniela Tendler Leibel Bacellar Cleber Hooper Alexandre Alves Souza Oliveira Dias Cristina Barbosa Silva Aline Moreira de Souza Simone Ramos Ricardo Alexandre Santos Thainara Ramos Pinto Mariana Antunes Ramo Ana Luíza MattosGuaraldi 《动物模型与实验医学(英文)》2020,3(4):304
BackgroundAnimal models are widely used in scientific research in order to obtain information from a whole organism under a specific set of experimental conditions. Various lineages of mice have been used to investigate diseases and new therapeutic strategies, and, consequently, hematological and biochemical tests in these laboratory animals are essential to validate scientific studies. Our study seeks to establish reference values for hematological and biochemical parameters of four lineages of mice.MethodsWe evaluated the hematological and biochemical profiles of 20 males and 20 females from the lineages Swiss (heterogeneous), BALB/c and C57BL/6 (isogenic), and B6D2F1 (hybrid), totaling 160 mice. Analysis were standardized using the systems pocH‐100iV Diff™ for 19 hematological parameters and VITROS® 350 for 12 biochemical parameters.ResultsResults are shown as means and standard deviation, grouped by lineage and genre. Comparing the values obtained in this study with the values from previous studies, some variations were detected, which could be explained by differences in methodologies or individual variability.ConclusionThus our study shows that knowledge and disclosure of the values of physiological parameters of laboratory animals is necessary, and emphasises the importance of considering variations influenced by gender, lineage and genotype in the choice of the best experimental model. 相似文献
69.
Erica S. Shenoy Farzad Noubary JiYeon Kim Eric S. Rosenberg Jessica A. Cotter Hang Lee Rochelle P. Walensky David C. Hooper 《Journal of clinical microbiology》2014,52(4):1235-1237
The effect of concurrent administration of antibiotics on the detection of methicillin-resistant Staphylococcus aureus (MRSA) remains unresolved. Here, we assessed the concordance of paired nasal swabs processed using commercial PCR and culture and found high concordance in both the absence and presence of antibiotics with activity against MRSA (93.7% [95% confidence interval [CI], 88.1%, 96.8%] and 90.9% [95% CI, 84.8%, 94.7%], respectively), although PCR was more likely to be positive in the presence of antibiotics. (This study has been registered at ClinicalTrials.gov under registration no. .) NCT01234831相似文献
70.
Holly McKnight W. Patrick Kelsey Deborah A. Hooper Thomas C. Hart Angelo Mariotti 《Journal of periodontology》2014,85(6):810-818
Background: Although human gingival fibroblasts (hGFs) and human periodontal ligament fibroblasts (hPDLFs) exhibit numerous phenotypic similarities, it has been suggested that the secretory and behavioral differences, which exist between these cell types, are a result of the membrane protein composition of these cells. Methods: Four matched pairs of hGFs and hPDLFs were cultured. Before confluence, membrane‐bound and ‐associated proteins from cells of the fourth passage were extracted. The processed protein samples were evaluated using capillary‐liquid chromatography‐nanospray tandem mass spectrometry. Global protein identification was performed on an orbitrap mass spectrometer equipped with a microspray source operated in positive ion mode. Proteome software was used to validate protein identifications derived from tandem mass spectrometry sequencing results. Results: Four hundred fifty proteins were common to both hGFs and hPDLFs. Of the proteins identified, 214 were known membrane‐bound or ‐associated proteins, and 165 proteins were known nuclear‐associated proteins. Twenty‐seven proteins, identified from the 450 proteins, common to both hGFs and hPDLFs, were detected in statistically significant greater quantities in either hGFs or hPDLFs. More specifically, 13 proteins were detected in significantly greater quantities in hGFs, whereas 14 proteins were detected in significantly greater quantities in hPDLFs. Conclusions: Distinct differences in the cellular protein catalog may reflect the dynamic role and high energy requirements of hGFs in extracellular matrix remodeling and response to inflammatory challenge as well as the role of hPDLFs in monitoring mechanical stress and maintaining tissue homeostasis during regeneration and remineralization. 相似文献