全文获取类型
收费全文 | 70615篇 |
免费 | 6514篇 |
国内免费 | 4021篇 |
专业分类
耳鼻咽喉 | 597篇 |
儿科学 | 1109篇 |
妇产科学 | 1148篇 |
基础医学 | 7962篇 |
口腔科学 | 1276篇 |
临床医学 | 8144篇 |
内科学 | 11280篇 |
皮肤病学 | 877篇 |
神经病学 | 3393篇 |
特种医学 | 2804篇 |
外国民族医学 | 35篇 |
外科学 | 8276篇 |
综合类 | 10912篇 |
现状与发展 | 16篇 |
一般理论 | 18篇 |
预防医学 | 4763篇 |
眼科学 | 1736篇 |
药学 | 7472篇 |
63篇 | |
中国医学 | 3653篇 |
肿瘤学 | 5616篇 |
出版年
2024年 | 212篇 |
2023年 | 969篇 |
2022年 | 2375篇 |
2021年 | 3211篇 |
2020年 | 2394篇 |
2019年 | 2173篇 |
2018年 | 2323篇 |
2017年 | 2085篇 |
2016年 | 2058篇 |
2015年 | 2853篇 |
2014年 | 3646篇 |
2013年 | 3642篇 |
2012年 | 5114篇 |
2011年 | 5448篇 |
2010年 | 3608篇 |
2009年 | 2962篇 |
2008年 | 3935篇 |
2007年 | 3984篇 |
2006年 | 3687篇 |
2005年 | 3455篇 |
2004年 | 2795篇 |
2003年 | 2662篇 |
2002年 | 2388篇 |
2001年 | 1998篇 |
2000年 | 1828篇 |
1999年 | 1614篇 |
1998年 | 877篇 |
1997年 | 884篇 |
1996年 | 707篇 |
1995年 | 609篇 |
1994年 | 524篇 |
1993年 | 363篇 |
1992年 | 556篇 |
1991年 | 473篇 |
1990年 | 434篇 |
1989年 | 387篇 |
1988年 | 301篇 |
1987年 | 297篇 |
1986年 | 237篇 |
1985年 | 174篇 |
1984年 | 127篇 |
1983年 | 94篇 |
1982年 | 69篇 |
1981年 | 78篇 |
1980年 | 44篇 |
1979年 | 79篇 |
1978年 | 42篇 |
1974年 | 37篇 |
1973年 | 33篇 |
1972年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Calculus bovis is commonly used for the treatment of stroke in traditional Chinese medicine. Hyodeoxycholic acid(HDCA) is a bioactive compound extracted from calculus bovis. When combined with cholic acid, baicalin and jas-minoidin, HDCA prevents hypoxia-reoxygenation-induced brain injury by suppressing endoplasmic reticulum stress-mediated apoptotic signaling. However, the effects of HDCA in ischemic stroke injury have not yet been studied. Neurovascular unit(NVU) dysfunction occurs in ischemic stroke. Therefore, in this study, we investigated the effects of HDCA on the NVU under ischemic conditions in vitro. We co-cultured primary brain microvascular endothelial cells, neurons and astrocytes using a transwell chamber co-culture system. The NVU was pre-treated with 10.16 or 2.54 μg/mL HDCA for 24 hours before exposure to oxygen-glucose deprivation for 1 hour. The cell counting kit-8 assay was used to detect cell activity. Flow cytometry and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling were used to assess apoptosis. Enzyme-linked immunosorbent assay was used to measure the expression levels of inflammatory cytokines, including interleukin-1β, interleukin-6 and tumor necrosis factor-α, and neurotrophic factors, including brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor. Oxidative stress-related factors, such as superoxide dismutase, nitric oxide, malondialdehyde and γ-glutamyltransferase, were measured using kits. Pretreatment with HDCA significantly decreased blood-brain barrier permeability and neuronal apoptosis, significantly increased transendothelial electrical resistance and γ-glutamyltransferase activity, attenuated oxidative stress damage and the release of inflammatory cytokines, and increased brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor expression. Our findings suggest that HDCA maintains NVU morphological integrity and function by modulating inflammation, oxidation stress, apoptosis, and the expression of neurotrophic factors. Therefore, HDCA may have therapeutic potential in the clinical management of ischemic stroke. This study was approved by the Ethics Committee of Experimental Animals of Beijing University of Chinese Medicine(approval No. BUCM-3-2016040201-2003) in April 2016. 相似文献
12.
Peng Cheng Linlin Yang Xiaodan Huang Xuejun Wang Maoqing Gong 《Archiv der Pharmazie》2020,353(4):1900350
Malaria, one of the most striking, re-emerging infectious diseases caused by the genus Plasmodium, places a huge burden on global healthcare systems. A major challenge in the control and eradication of malaria is the continuous emergence of increasingly widespread drug-resistant malaria, creating an urgent need to develop novel antimalarial agents. Chalcone derivatives are ubiquitous in nature and have become indispensable units in medicinal chemistry applications due to their diverse biological profiles. Many chalcone derivatives demonstrate potential in vitro and in vivo antimalarial activity, so chalcone could be a useful template for the development of novel antimalarial agents. This review covers the recent development of chalcone hybrids as antimalarial agents. The critical aspects of the design and structure–activity relationship of these compounds are also discussed. 相似文献
13.
Micro‐evolution of the hepatitis B virus genome in hepatitis B e‐antigen‐positive carriers: Comparison of genotypes B and C at various immune stages 下载免费PDF全文
14.
15.
白细胞介素4(IL-4)是T辅助2(Th2)介导的免疫反应的基本免疫调节细胞因子,IL-4具有复杂的信号系统和多效的功能,但在脑组织中,诸多研究发现IL-4可在炎症中保护认知功能。该文总结了关于IL-4保护认知功能的证据及机制,以及在阿尔茨海默病、缺血性脑血管病以及手术后认知功能障碍中IL-4保护认知功能的途径及证据。 相似文献
16.
Chen Rong Zhang Yuan Huang Lei Cheng Bi-heng Xia Zhong-yuan Meng Qing-tao 《Journal canadien d'anesthésie》2020,67(6):655-663
Canadian Journal of Anesthesia/Journal canadien d'anesthésie - To assess the management and safety of epidural or general anesthesia for Cesarean delivery in parturients with coronavirus... 相似文献
17.
18.
19.
目的回顾我院药物代谢酶和药物作用靶点相关基因检测与精准药学服务实践过程,总结经验,与同行分享。方法从准备工作、相关检测项目的确定,学术推广、项目优化和开展情况等方面详细阐述我院基因检测开展过程与精准药学服务情况。结果根据临床需求,我院已开展了以心脑血管药和抗精神病药为主的27种药物,26项检测,2018年全年位1587名患者提供个体化用药建议,受到临床医生和患者欢迎。结论基于代谢酶和药物作用靶点相关基因检测的个体化用药建议是临床药师参与精准治疗的重要途径,有助于医生和药师之间的沟通,有利于提高药学服务水平。 相似文献
20.
OBJECTIVES: To assess the effectiveness and safety of additional bedtime H2‐receptor antagonists (H2RAs) in suppressing nocturnal gastric acid breakthrough (NAB) via a systematic review. METHODS: Eligible trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 2, 2004), MEDLINE (January 1966–June 2004), EMBASE (January 1980–June 2004) and CINAHL (January 1982–June 2004). Additional hand‐searching was conducted on the proceedings of correlated conferences, eight important Chinese journals and references of all included trials. All randomized controlled trials evaluating H2RAs for the control of NAB were eligible for inclusion. The systematic review was conducted using methods recommended by The Cochrane Collaboration. RESULTS: Only two randomized crossover studies, comprising 32 participants, met the inclusion criteria. Because the design, dosage and duration of the treatments were different between the studies, it was not possible to conduct meta‐analysis. There were no consistent conclusions found between the two included studies in evaluating H2RAs for the control of NAB. CONCLUSIONS: No implications for practice at this stage can be concluded. Appropriately designed large‐scale randomized controlled trials with long‐term follow up are needed to determine the effects of additional bedtime H2RAs in suppressing NAB. 相似文献