全文获取类型
收费全文 | 6909篇 |
免费 | 681篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 226篇 |
妇产科学 | 96篇 |
基础医学 | 1035篇 |
口腔科学 | 136篇 |
临床医学 | 825篇 |
内科学 | 1406篇 |
皮肤病学 | 85篇 |
神经病学 | 580篇 |
特种医学 | 381篇 |
外国民族医学 | 1篇 |
外科学 | 654篇 |
综合类 | 196篇 |
一般理论 | 2篇 |
预防医学 | 722篇 |
眼科学 | 114篇 |
药学 | 690篇 |
中国医学 | 9篇 |
肿瘤学 | 438篇 |
出版年
2022年 | 47篇 |
2021年 | 98篇 |
2020年 | 66篇 |
2019年 | 80篇 |
2018年 | 93篇 |
2017年 | 101篇 |
2016年 | 101篇 |
2015年 | 135篇 |
2014年 | 166篇 |
2013年 | 243篇 |
2012年 | 320篇 |
2011年 | 351篇 |
2010年 | 197篇 |
2009年 | 201篇 |
2008年 | 347篇 |
2007年 | 329篇 |
2006年 | 346篇 |
2005年 | 316篇 |
2004年 | 288篇 |
2003年 | 251篇 |
2002年 | 212篇 |
2001年 | 232篇 |
2000年 | 225篇 |
1999年 | 203篇 |
1998年 | 123篇 |
1997年 | 111篇 |
1996年 | 101篇 |
1995年 | 119篇 |
1994年 | 75篇 |
1993年 | 92篇 |
1992年 | 138篇 |
1991年 | 158篇 |
1990年 | 132篇 |
1989年 | 158篇 |
1988年 | 127篇 |
1987年 | 140篇 |
1986年 | 114篇 |
1985年 | 132篇 |
1984年 | 89篇 |
1983年 | 57篇 |
1982年 | 57篇 |
1981年 | 67篇 |
1980年 | 53篇 |
1979年 | 74篇 |
1978年 | 50篇 |
1977年 | 52篇 |
1976年 | 49篇 |
1975年 | 60篇 |
1974年 | 42篇 |
1973年 | 45篇 |
排序方式: 共有7664条查询结果,搜索用时 15 毫秒
1.
2.
Toidi Adekambi Chris C. Ibegbu Stephanie Cagle Ameeta S. Kalokhe Yun F. Wang Yijuan Hu Cheryl L. Day Susan M. Ray Jyothi Rengarajan 《The Journal of clinical investigation》2015,125(5):1827-1838
BACKGROUND. The identification and treatment of individuals with tuberculosis (TB) is a global public health priority. Accurate diagnosis of pulmonary active TB (ATB) disease remains challenging and relies on extensive medical evaluation and detection of Mycobacterium tuberculosis (Mtb) in the patient’s sputum. Further, the response to treatment is monitored by sputum culture conversion, which takes several weeks for results. Here, we sought to identify blood-based host biomarkers associated with ATB and hypothesized that immune activation markers on Mtb-specific CD4+ T cells would be associated with Mtb load in vivo and could thus provide a gauge of Mtb infection.METHODS. Using polychromatic flow cytometry, we evaluated the expression of immune activation markers on Mtb-specific CD4+ T cells from individuals with asymptomatic latent Mtb infection (LTBI) and ATB as well as from ATB patients undergoing anti-TB treatment.RESULTS. Frequencies of Mtb-specific IFN-γ+CD4+ T cells that expressed immune activation markers CD38 and HLA-DR as well as intracellular proliferation marker Ki-67 were substantially higher in subjects with ATB compared with those with LTBI. These markers accurately classified ATB and LTBI status, with cutoff values of 18%, 60%, and 5% for CD38+IFN-γ+, HLA-DR+IFN-γ+, and Ki-67+IFN-γ+, respectively, with 100% specificity and greater than 96% sensitivity. These markers also distinguished individuals with untreated ATB from those who had successfully completed anti-TB treatment and correlated with decreasing mycobacterial loads during treatment.CONCLUSION. We have identified host blood-based biomarkers on Mtb-specific CD4+ T cells that discriminate between ATB and LTBI and provide a set of tools for monitoring treatment response and cure.TRIAL REGISTRATION. Registration is not required for observational studies.FUNDING. This study was funded by Emory University, the NIH, and the Yerkes National Primate Center. 相似文献
3.
4.
Andrea DiMartini Nancy Day Mary Amanda Dew Lubna Javed Mary Grace Fitzgerald Ashok Jain John J Fung Paulo Fontes 《Liver transplantation》2006,12(5):813-820
For patients who receive a liver transplant (LTX) for alcoholic liver disease (ALD), investigators are focusing beyond survival to determine specific alcohol use outcomes. Studies suggest the use of alcohol ranges from 8 to 22% for the first post-transplant year with cumulative rates reaching 30 to 40% by 5 years following transplantation. Yet while investigators are interested in determining specific rates of alcohol use and predictors of use, only three studies since 1990 have been prospective. In 1998, we began a prospective study of post-LTX alcohol consumption in ALD recipients using multiple repeated measures of alcohol use. After 5 years of follow-up, we found that 22% had used any alcohol by the first year and 42% had a drink by 5 years. By 5 years, 26% drank at a heavier use (binge) pattern and 20% drank in a frequent pattern. In a univariate model, predictors of alcohol use included pre-transplant length of sobriety, a diagnosis of alcohol dependence, a history of other substance use, and prior alcohol rehabilitation. 相似文献
5.
6.
7.
The response of single detergent treated bovine retinal pigment epithelial cells in culture to ATP was measured with an image analyser. The most pronounced contraction was produced by 1.0 mM ATP with most change taking place in the first 10 min. At 1 h the area had decreased by about 33%, perimeter 22% and maximum length 25%. By way of comparison rabbit skin fibroblasts had a decreased area of approximately 40%, perimeter 25% and maximum length 22%. Bovine aortic smooth muscle cells on the other hand decreased in area by 55%, perimeter 40% and maximum length 36%. It is hoped that this assay may be used to evaluate drugs which could counteract contractile events in proliferative vitreoretinopathy. 相似文献
8.
The extent to which repeated administration produces tolerance to nicotine-induced increases in dopamine transmission in the nucleus accumbens was investigated in rats. In vivo microdialysis was used to sample extracellular dopamine and metabolites after a nicotine challenge (0.35 mg/kg) in (1) naive rats, (2) acutely pretreated rats (1 prior nicotine injection), and (3) chronically pretreated rats (12-15 prior daily nicotine injections, 0.35 mg/kg per injection). Nicotine increased extracellular DA and its metabolites, and these increases were not significantly altered by either acute or chronic prior exposure to the drug. The failure to find evidence of tolerance is compatible with the hypothesis that the mesolimbic dopaminergic system is a substrate for the reinforcing properties of chronically administered nicotine. 相似文献
9.
Vanaporn Wuthiekanun Varunee Desakorn Gumphol Wongsuvan Premjit Amornchai Allen C. Cheng Bina Maharjan Direk Limmathurotsakul Wirongrong Chierakul Nicholas J. White Nicholas P. J. Day Sharon J. Peacock 《Clinical and Vaccine Immunology : CVI》2005,12(4):555-556
An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were prospectively compared with the culture results for 776 specimens from patients with suspected melioidosis. The sensitivities of both IF tests were 66%, and the specificities were 99.5 and 99.4%, respectively. 相似文献
10.