首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   31327篇
  免费   1981篇
  国内免费   195篇
耳鼻咽喉   370篇
儿科学   955篇
妇产科学   620篇
基础医学   3566篇
口腔科学   1014篇
临床医学   2520篇
内科学   6941篇
皮肤病学   643篇
神经病学   2008篇
特种医学   805篇
外国民族医学   6篇
外科学   5039篇
综合类   725篇
一般理论   25篇
预防医学   2328篇
眼科学   1043篇
药学   2683篇
中国医学   274篇
肿瘤学   1938篇
  2023年   333篇
  2022年   343篇
  2021年   1305篇
  2020年   1040篇
  2019年   1237篇
  2018年   1488篇
  2017年   1036篇
  2016年   1161篇
  2015年   1231篇
  2014年   1652篇
  2013年   1946篇
  2012年   2715篇
  2011年   2794篇
  2010年   1665篇
  2009年   1310篇
  2008年   1906篇
  2007年   1863篇
  2006年   1662篇
  2005年   1458篇
  2004年   1248篇
  2003年   1091篇
  2002年   901篇
  2001年   225篇
  2000年   190篇
  1999年   168篇
  1998年   128篇
  1997年   74篇
  1996年   97篇
  1995年   92篇
  1994年   73篇
  1993年   79篇
  1992年   95篇
  1991年   79篇
  1990年   73篇
  1989年   81篇
  1988年   68篇
  1987年   45篇
  1986年   57篇
  1985年   45篇
  1984年   45篇
  1983年   48篇
  1982年   41篇
  1981年   44篇
  1980年   34篇
  1979年   29篇
  1978年   30篇
  1977年   20篇
  1976年   23篇
  1974年   18篇
  1973年   19篇
排序方式: 共有10000条查询结果,搜索用时 27 毫秒
1.
PurposeThe clinical manifestations of rickettsial diseases mimic other endemic infections with similar presentations thus posing a serious challenge to clinicians for their diagnosis. For the diagnosis of rickettsial disease serological tests like Weil Felix, ELISA and IFA are used. There are limited studies that have evaluated different serological tests for the diagnosis of rickettsial diseases. Therefore, the present study was undertaken to evaluate the ELISA and Weil Felix test for the diagnosis of rickettsial diseases prevalent in this region.MethodsSamples from 281 patients clinically suspected of rickettsial diseases were tested for spotted fever group (SFG), typhus group (TG) and scrub typhus group (STG) by Weil Felix, ELISA and IFA was taken as the gold standard. Baseline titers and cut-off ODs were calculated by taking samples from healthy blood donors.ResultsThe sensitivity, specificity, positive and negative predictive value of Weil Felix test ranged from 30% to 44%, 83.46%–97.86%, 9%–77%, 92–96% respectively. The sensitivity and specificity, positive and negative predictive value of ELISA ranged from 80.77% to 96.15%, 96.33%–98.43%, 70.21%–88.64%, 92.89%–99.60% respectively. Maximum cross-reactions were observed between SFG and STG by the Weil Felix test and between STG and TG by ELISA.ConclusionsELISA was found to be sensitive and specific for the diagnosis of rickettsial diseases. It is easy to perform, does not require a technical expert for result interpretation and a large number of samples can be processed at a time.  相似文献   
2.
3.
4.
5.
Inflammopharmacology - COVID-19 is one of the viral diseases that has caused many deaths and financial losses to humans. Using the available information, this virus appears to activate the host...  相似文献   
6.
7.
8.
Dengue, a mosquito‐borne viral disease, causes about 100 million cases of infection annually. It is a major public concern, and if left untreated or improperly diagnosed, may cause serious health problems or even death. Historically, dengue has not considered priorities for pharmaceutical companies made the available treatment options. Therefore, medicinal scientists are revealing new insights and enabling novel interventions and approaches to dengue prevention and control. Diterpenes, a class of terpenes have gained much attention due to their diverse biological effects. This review aimed at summarizing available evidences of diterpenes and their derivatives acting against dengue virus and their vectors. For this, an updated search was made in the databases: PubMed and ScienceDirect by using specific keywords. Among the 117 published reports, a total of 30 articles was included in this review. Findings suggest that a number of diterpenes and/or their derivatives act against dengue virus and their two potential vectors namely Aedes aegypti and Ae. albopictus. In conclusion, diterpenes and their derivatives may have the potential alternative therapeutic tools for the management of dengue virus and some associated diseases transmitted by Aedes mosquito.  相似文献   
9.
ObjectivesNigella sativa (NS) is a known medicinal herb with numerous therapeutic effects such as antidiabetic, anti-proliferative, anti-inflammatory, and anti-cancer activities. It has been indicated that NS can regulate cellular metabolism by adjusting transduction signaling pathways. Adenosine monophosphate-activated protein kinase (AMPK) is one of the main physiological processes, such as energy hemostasis, cellular metabolism, and autophagy regulators. Herb-derived medicines have always been considered as one of the main AMPK activators, and surprisingly recent data has demonstrated that it can be a target for NS and its derivatives.Evidence acquisitionThe literature search was conducted in PubMed, SCOPUS, Embase, ProQuest, and Google Scholar electronic resources. Published articles up to September 2020 were considered, and those of which investigated Nigella sativa effects on the AMPK pathway after meeting the inclusion criteria were included.ResultsThe search was performed on several online databases such as PubMed, Scopus, Embase, ProQuest, and Google Scholar from inception until January 2020. Among the initial search, 245 studies were found. After removing duplicated data and meeting the inclusion criteria, only 14 studies were selected. They included the effects of NS and its bioactive compounds as anti-hyperglycemic (n = 5), on liver function (n = 4), cancers (n = 3), and on Neuroinflammation and Atherosclerosis (n = 2). Most of the included studies are animals or in-vitro investigations.ConclusionIn this review, we discuss the latest findings on the molecular mechanism of NS effecting the AMPK signaling pathway. We also focus on the therapeutic effects of NS, including the prevention and treatment of metabolic and pro-inflammatory disease by targeting the AMPK pathway.Graphical abstract  相似文献   
10.
Objectives: Increases in astrocytes and one of their markers, glial fibrillary acidic protein (GFAP) have been reported in the brains of patients with Alzheimer’s disease (AD). N-3 polyunsaturated fatty acids (PUFA) modulate neuroinflammation in animal models; however, their effect on astrocytes is unclear.

Methods: Fat-1 mice and their wildtype littermates were fed either a fish oil diet or a safflower oil diet deprived of n-3 PUFA. At 12 weeks, mice underwent intracerebroventricular infusion of amyloid-β 1-40. Astrocyte phenotype in the hippocampus was assessed at baseline and 10 days post-surgery using immunohistochemistry with various microscopy and image analysis techniques.

Results: GFAP increased in all groups in response to amyloid-β, with a greater increase in fish oil-fed mice than either fat-1 or wildtype safflower oil-fed mice. Astrocytes in this group were also more hypertrophic, suggesting increased activation. Both fat-1- and fish oil-fed mice had greater increases in branch number and length in response to amyloid-β infusion than wildtype safflower animals.

Conclusion: Fish oil feeding, and to a lesser extent the fat-1 transgene, enhances the astrocyte activation phenotype in response to amyloid-β 1-40. Astrocytes in mice fed fish oil were more activated in response to amyloid-β than in fat-1 mice despite similar levels of hippocampal n-3 PUFA, which suggests that other fatty acids or dietary factors contribute to this effect.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号