全文获取类型
收费全文 | 6798篇 |
免费 | 649篇 |
国内免费 | 294篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 77篇 |
妇产科学 | 103篇 |
基础医学 | 1671篇 |
口腔科学 | 70篇 |
临床医学 | 497篇 |
内科学 | 1117篇 |
皮肤病学 | 105篇 |
神经病学 | 915篇 |
特种医学 | 180篇 |
外科学 | 466篇 |
综合类 | 636篇 |
现状与发展 | 3篇 |
预防医学 | 281篇 |
眼科学 | 117篇 |
药学 | 611篇 |
中国医学 | 250篇 |
肿瘤学 | 562篇 |
出版年
2024年 | 9篇 |
2023年 | 122篇 |
2022年 | 160篇 |
2021年 | 268篇 |
2020年 | 205篇 |
2019年 | 231篇 |
2018年 | 213篇 |
2017年 | 213篇 |
2016年 | 263篇 |
2015年 | 260篇 |
2014年 | 403篇 |
2013年 | 440篇 |
2012年 | 364篇 |
2011年 | 410篇 |
2010年 | 328篇 |
2009年 | 371篇 |
2008年 | 365篇 |
2007年 | 362篇 |
2006年 | 351篇 |
2005年 | 301篇 |
2004年 | 229篇 |
2003年 | 238篇 |
2002年 | 142篇 |
2001年 | 127篇 |
2000年 | 109篇 |
1999年 | 122篇 |
1998年 | 85篇 |
1997年 | 87篇 |
1996年 | 69篇 |
1995年 | 95篇 |
1994年 | 83篇 |
1993年 | 78篇 |
1992年 | 48篇 |
1991年 | 41篇 |
1990年 | 43篇 |
1989年 | 50篇 |
1988年 | 50篇 |
1987年 | 41篇 |
1986年 | 26篇 |
1985年 | 49篇 |
1984年 | 72篇 |
1983年 | 43篇 |
1982年 | 52篇 |
1981年 | 23篇 |
1980年 | 21篇 |
1979年 | 11篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 8篇 |
排序方式: 共有7741条查询结果,搜索用时 15 毫秒
1.
2.
目的从细胞因子角度,探究人参败毒散多成分、多靶点、多途径抗新型冠状病毒肺炎(COVID-19)的作用机制。方法应用中药系统药理分析平台(TCMSP)收集人参败毒散中活性化合物,结合药物靶点数据库收集细胞因子风暴相关靶点,利用Cytoscape构建"药材-化合物-疾病靶点"网络。通过String和DAVID数据库对靶点的互作网络、GO功能和KEGG通路进行分析。结果人参败毒散"药材-活性化合物-疾病靶点"网络包括10种药材,211个活性成分和151个疾病靶点。互作网络发现人参败毒散抑制细胞因子风暴治疗COVID-19的靶点可能包含STAT3、MAPK1、NFκB1、PIK3CA、MAPK3、TNF、CXCR4、VEGFA、IL-6、IL-2等。GO功能分析发现上述靶点在生物功能方面涉及趋化性、类固醇代谢过程等;在分子功能方面涉及血红素结合、铁离子结合、氧结合等;在细胞组成方面涉及细胞表面、细胞膜等。KEGG通路富集发现上述靶点参与查加斯病通路、HIF-1信号通路、肿瘤坏死因子信号通路等的调控。结论人参败毒散可能通过调节趋化性细胞因子,增加血氧饱和度,抑制STAT、MAPK、NFκB、PIK3K、IL-6等炎症相关信号通路,实现多成分-多靶点-多途径抑制细胞因子风暴形成的抗COVID-19作用。 相似文献
3.
The advent of nanotechnology has revolutionized the way clinicians are treating cancers. Treatment for cancer includes surgery, radiotherapy, hormonal therapy, chemotherapy, and now nano therapy, which could be a possible alternative. This new treatment regime can be beneficial since it shows minimum side effects as compared to other treatment methods. Metallic nanoparticles synthesized through green chemistry by using biological entities minimizes the side effects and enhances the properties of the metal against cancer cells. These green nanoparticles are widely used in research and have shown promising cytotoxic activity against various cancer cell lines. Mechanistically, these nanoparticles can enter the cancer cell and cause cell death by the activation of various molecular pathways such as apoptosis, necrosis and autophagy. This review focuses on the metal nanoparticles (silver, gold and copper) synthesized by the green chemistry approach that have been utilized to study the cancer cell death and we are also discussing the underlying molecular pathways. 相似文献
4.
孕烷X受体(Pregnane X receptor,PXR)是核受体家族成员之一,可被多种内源性和外源性物质激活。PXR通过诱导药物代谢酶和转运体,在肝脏、肠道、皮肤和血管内皮中发挥重要的解毒作用。此外,PXR还具有调节糖脂代谢、胆固醇代谢、胆红素和胆汁酸代谢、免疫炎症反应等功能。研究证实,PXR已被公认为多种炎症性疾病的有效药物干预靶点,如炎性结肠炎、坏死性肠炎、肝炎、皮炎、糖尿病等。多种中药或其活性成分可以作为PXR受体激动剂通过核因子B(NF-κB)和尾部相关同源盒转录因子2(Cdx2)通路干扰炎症反应,如虎杖、木蝴蝶、黄芩、黄连、丹参、白芷、人参、香附、五味子、高良姜等。本文综述了近年来PXR调节炎症反应的最新研究成果以及中药激活PXR干预炎症反应的机制,以期为今后的研究提供参考。 相似文献
5.
Zi-Qi Shao Shan-Shan Dou Jun-Ge Zhu Hui-Qing Wang Chun-Mei Wang Bao-Hua Cheng Bo Bai 《中国神经再生研究》2021,16(6):1044
Apelin-13 is a novel endogenous ligand for an angiotensin-like orphan G-protein coupled receptor, and it may be neuroprotective against cerebral ischemia injury. However, the precise mechanisms of the effects of apelin-13 remain to be elucidated. To investigate the effects of apelin-13 on apoptosis and autophagy in models of cerebral ischemia/reperfusion injury, a rat model was established by middle cerebral artery occlusion. Apelin-13(50 μg/kg) was injected into the right ventricle as a treatment. In addition, an SH-SY5 Y cell model was established by oxygen-glucose deprivation/reperfusion, with cells first cultured in sugar-free medium with 95% N2 and 5% CO2 for 4 hours and then cultured in a normal environment with sugar-containing medium for 5 hours. This SH-SY5 Y cell model was treated with 10–7 M apelin-13 for 5 hours. Results showed that apelin-13 protected against cerebral ischemia/reperfusion injury. Apelin-13 treatment alleviated neuronal apoptosis by increasing the ratio of Bcl-2/Bax and significantly decreasing cleaved caspase-3 expression. In addition, apelin-13 significantly inhibited excessive autophagy by regulating the expression of LC3 B, p62, and Beclin1. Furthermore, the expression of Bcl-2 and the phosphatidylinositol-3-kinase(PI3 K)/Akt/mammalian target of rapamycin(mTOR) pathway was markedly increased. Both LY294002(20 μM) and rapamycin(500 nM), which are inhibitors of the PI3 K/Akt/mTOR pathway, significantly attenuated the inhibition of autophagy and apoptosis caused by apelin-13. In conclusion, the findings of the present study suggest that Bcl-2 upregulation and mTOR signaling pathway activation lead to the inhibition of apoptosis and excessive autophagy. These effects are involved in apelin-13-induced neuroprotection against cerebral ischemia/reperfusion injury, both in vivo and in vitro. The study was approved by the Animal Ethical and Welfare Committee of Jining Medical University, China(approval No. 2018-JS-001) in February 2018. 相似文献
6.
Hui-Ling Wang Fei-Lai Liu Rui-Qing Li Ming-Yue Wan Jie-Ying Li Jing Shi Ming-Li Wu Jun-Hua Chen Wei-Juan Sun Hong-Xia Feng Wei Zhao Jin Huang Ren-Chao Liu Wen-Xue Hao Xiao-Dong Feng 《中国神经再生研究》2021,16(6):1011
Electroacupuncture has been widely used to treat cognitive impairment after cerebral ischemia, but the underlying mechanism has not yet been fully elucidated. Studies have shown that autophagy plays an important role in the formation and development of cognitive impairment, and the phosphoinositide 3-kinase(PI3 K)/Akt signaling pathway plays an important role in autophagy regulation. To investigate the role played by the PI3 K/Akt signaling pathway in the electroacupuncture treatment of cerebral ischemia/reperfusion rat models, we first established a rat model of cerebral ischemia/reperfusion through the occlusion of the middle cerebral artery using the suture method. Starting at 2 hours after modeling, electroacupuncture was delivered at the Shenting(GV24) and Baihui(GV20) acupoints, with a dilatational wave(1–20 Hz frequency, 2 mA intensity, 6 V peak voltage), for 30 minutes/day over 8 consecutive days. Our results showed that electroacupuncture reduced the infarct volume in a rat model of cerebral ischemia/reperfusion injury, increased the mRNA expression levels of the PI3 K/Akt signaling pathwayrelated factors Beclin-1, mammalian target of rapamycin(mTOR), and PI3 K, increased the protein expression levels of phosphorylated Akt, Beclin-1, PI3 K, and mTOR in the ischemic cerebral cortex, and simultaneously reduced p53 mRNA and protein expression levels. In the Morris water maze test, the latency to find the hidden platform was significantly shortened among rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation. In the spatial probe test, the number of times that a rat crossed the target quadrant was increased in rats subjected to electroacupuncture stimulation compared with rats without electroacupuncture stimulation. Electroacupuncture stimulation applied to the Shenting(GV24) and Baihui(GV20) acupoints activated the PI3 K/Akt signaling pathway and improved rat learning and memory impairment. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Henan University of Traditional Chinese Medicine, China(approval No. 8150150901) on March 10, 2016. 相似文献
7.
Chancellor F. Gray Hernan A. Prieto Justin T. Deen Hari K. Parvataneni 《The Journal of arthroplasty》2019,34(2):206-210
Background
Revision total joint arthroplasty (TJA) is associated with increased readmissions, complications, and expense compared to primary TJA. Bundled payment methods have been used to improve value of care in primary TJA, but little is known of their impact in revision TJA patients. The purpose of this study is to evaluate the impact of a care redesign for a bundled payment model for primary TJA on quality metrics for revision patients, despite absence of a targeted intervention for revisions.Methods
We compared quality metrics for all revision TJA patients including readmission rate, use of post–acute care facility after discharge, length of stay, and cost, between the year leading up to the redesign and the 2 years following its implementation. Changes in the primary TJA group over the same time period were also assessed for comparison.Results
Despite a volume increase of 37% over the study period, readmissions declined from 8.9% to 5.8%. Use of post–acute care facilities decreased from 42% to 24%. Length of stay went from 4.84 to 3.92 days. Cost of the hospital episode declined by 5%.Conclusion
Our health system experienced a halo effect from our bundled payment-influenced care redesign, with revision TJA patients experiencing notable improvements in several quality metrics, though not as pronounced as in the primary TJA population. These changes benefitted the patients, the health system, and the payers. We attribute these positive changes to an altered institutional mindset, resulting from an invested and aligned care team, with active physician oversight over the care episode. 相似文献8.
9.
MOB1A regulates glucose deprivation-induced autophagy via IL6-STAT3 pathway in gallbladder carcinoma
Bo Yang Yang Li Rui Zhang Liguo Liu Huijie Miao Yongsheng Li Ziyu Shao Tai Ren Yijian Zhang Qiyu Zhang Yingbin Liu Hongqi Shi 《American journal of cancer research》2020,10(11):3896
MOB kinase activator 1A (MOB1A) plays an important role in many diseases and cancers. Here, we observed that MOB1A was substantially overexpressed in gallbladder carcinoma (GBC) tissues compared with nontumor tissues. The high expression of MOB1A was closely associated with poor survival in patients with GBC at advanced TNM stages. Furthermore, our study indicated that MOB1A promoted autophagy by activating the IL6/STAT3 signaling pathway and regulating the chemosensitivity to gemcitabine under glucose deprivation conditions both in vitro and in vivo. In conclusion, these findings suggested that MOB1A is critical for the development of GBC via the MOB1A-IL6/STAT3-autophagy axis. 相似文献
10.
Pyruvic acid is important organic chemical intermediates that plays a role in cardiomyocyte pathophysiology and therapy. This study sought to explore the inotropic effects of pyruvic acid on the function of the isolated rat hearts and investigate its underlying mechanism. Pyruvic acid produced a greater negative inotropic effect compared to HCl and sodium pyruvate in a concentration-dependent pattern in the hearts. The role of low dose of pyruvic acid on heart function was regulated by pyruvic acid molecules and high dose pyruvic acid may be influenced by pyruvic acid molecules and pH. Kv channels may be involved in the pyruvic acid-induced negative inotropic effect. Finally, pyruvic acid markedly increased the level of LDH and CK and reduced the level of Ca2+Mg2+-ATPase and Na+K+-ATPase. These results suggest that pyruvic acid may modulate cardiac function at physiological or low doses but can cause damage to cardiomyocytes at high doses. 相似文献