全文获取类型
收费全文 | 112763篇 |
免费 | 11844篇 |
国内免费 | 7091篇 |
专业分类
耳鼻咽喉 | 1023篇 |
儿科学 | 2074篇 |
妇产科学 | 1269篇 |
基础医学 | 10578篇 |
口腔科学 | 1866篇 |
临床医学 | 15906篇 |
内科学 | 13507篇 |
皮肤病学 | 1242篇 |
神经病学 | 4485篇 |
特种医学 | 3694篇 |
外国民族医学 | 32篇 |
外科学 | 8179篇 |
综合类 | 24141篇 |
现状与发展 | 29篇 |
一般理论 | 10篇 |
预防医学 | 10610篇 |
眼科学 | 2883篇 |
药学 | 13474篇 |
174篇 | |
中国医学 | 9008篇 |
肿瘤学 | 7514篇 |
出版年
2024年 | 387篇 |
2023年 | 1633篇 |
2022年 | 4023篇 |
2021年 | 5602篇 |
2020年 | 4534篇 |
2019年 | 3518篇 |
2018年 | 3550篇 |
2017年 | 3898篇 |
2016年 | 3454篇 |
2015年 | 5164篇 |
2014年 | 6580篇 |
2013年 | 6981篇 |
2012年 | 9914篇 |
2011年 | 10464篇 |
2010年 | 7706篇 |
2009年 | 6472篇 |
2008年 | 7424篇 |
2007年 | 7165篇 |
2006年 | 6461篇 |
2005年 | 5568篇 |
2004年 | 3906篇 |
2003年 | 3525篇 |
2002年 | 2854篇 |
2001年 | 2219篇 |
2000年 | 1799篇 |
1999年 | 1417篇 |
1998年 | 807篇 |
1997年 | 767篇 |
1996年 | 602篇 |
1995年 | 556篇 |
1994年 | 525篇 |
1993年 | 336篇 |
1992年 | 309篇 |
1991年 | 294篇 |
1990年 | 231篇 |
1989年 | 217篇 |
1988年 | 198篇 |
1987年 | 149篇 |
1986年 | 116篇 |
1985年 | 93篇 |
1984年 | 46篇 |
1983年 | 47篇 |
1982年 | 15篇 |
1981年 | 31篇 |
1980年 | 18篇 |
1979年 | 19篇 |
1977年 | 14篇 |
1974年 | 12篇 |
1973年 | 12篇 |
1971年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
42.
目的探讨依维莫司联合全反式维甲酸(简称维甲酸)逆转急性早幼粒细胞白血病(APL)细胞株NB4-R1耐药的作用。方法应用CD11b染色流式细胞术及硝基四唑氮蓝(NBT)还原实验检测两药联合应用对细胞分化的影响, 流式细胞术检测细胞周期情况, Annexin V/PI双染色检测细胞凋亡情况, 蛋白质印迹法检测自噬相关蛋白微管结合蛋白轻链3(LC3)、Beclin 1及早幼粒白血病-维甲酸受体融合蛋白(PML-RARα)、磷酸化核糖体S6激酶(P-P70S6K)、磷酸化4E结合蛋白1(P-4E-BP1) 等表达水平。结果与维甲酸组比较, 联用组能诱导耐药细胞株NB4-R1细胞的分化, 并将细胞增殖阻止在G 1期而对细胞凋亡无明显影响。100 nmol/L依维莫司组、1μmol/L维甲酸组、联用组、对照组NB4-R1细胞培养48 h后分化百分率分别为(2.29±0.57)%、(17.06±2.65)%、(54.47±4.91)%、(2.54±0.53)%; 处于G 1期的细胞百分率分别为(35.20±11.97)%、(33.54±6.25)%、(53.70±8.73)%、(27.40±6.01)%; 四组细胞凋亡细胞百分率分别为(2.30±0.14)%、(2.25±0.21)%、(2.40±0.28)%、(1.95±0.07)%。与维甲酸组比较, 联用组mTOR信号通路下游的P70S6K、4E-BP1分子磷酸化水平下降, LC3-II和Beclin 1的表达上调, 且能部分降解融合蛋白PML-RARα。 结论依维莫司联合维甲酸能诱导NB4-R1细胞分化, 且能阻滞细胞周期而不致细胞凋亡, 其机制可能与依维莫司联合维甲酸抑制mTOR信号通路激活自噬作用从而降解PML-RARα蛋白有关。 相似文献
43.
Yaobin Ouyang Gongmeizi Liu Wenting Xu Zhen Yang Nianshuang Li Chuan Xie Chun Zhou Jiang Chen Yin Zhu Junbo Hong Nonghua Lu 《Oncology Letters》2021,21(2)
Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development. 相似文献
44.
目的探讨工作坊模式在护生压疮护理带教中的应用效果,为临床护理带教提供参考。方法选取2018年7月—2019年6月在医院实习的120名护生作为研究对象,随机分为对照组和观察组,各60名护生。对照组采用传统带教法进行压疮培训,观察组采用工作坊教学模式进行培训。培训结束后比较两组护生压疮知识的掌握程度即理论考核、技能操作成绩,教学效果满意度。结果观察组护生对压疮知识的掌握程度即理论考核成绩、技能操作考核成绩远远高于对照组,两组差异具有统计学意义(P<0.05)。95%的观察组护生对工作坊教学模式的效果表示满意,认为工作坊教学模式能够提高学习的兴趣、主动性和临床实践能力,对临床工作有很大帮助。结论工作坊教学模式应用于压疮护理的临床带教,能让护生亲身体验压疮护理的过程,并参与其中,将理论与实践相结合,更好地活跃课堂气氛,启发护生思考,提高护生对压疮理论和技能的掌握,为临床实际工作中压疮护理质量的提高奠定基础。 相似文献
45.
46.
47.
借力医院文化环境探索传染病专科医院研究生医德培养的方法及途径 《医学教育管理》2021,7(4):402-405
新医改环境下,临床医学人才的医德培养愈发重要,也越来越引起管理层重视。而医院文化环境对研究生医德培养可以起着潜移默化的引领作用,优秀的医院文化,能塑造并铸就研究生良好信念,强化研究生医德养成。结合传染病专科医院自身文化环境特点,探索传染病学研究生医德培养方式,对于传染病专科医院研究生医德培养具有一定理论指导意义。 相似文献
48.
Phytonutrients extracted from natural resources are receiving much attention among researchers due to their highly antioxidative characteristics which prevent several degenerative diseases including cardiovascular diseases and cancers. These nutraceutical compounds can be used in food, pharmaceutical and cosmetic products as natural antioxidants, preservatives, colourants and functional foods. Huge volume of food wastes are generated from the processing industry and these low-value food residues are rich in various phytonutrients worth recovering. This approach of valorisation reduces the generation of food wastes and is cost-effective considering the cheap feedstock, reduced waste management expenses and high market value of extracted compounds. In light of the health and safety risks posed by commonly used organic extraction solvents derived from the petrochemical industry, there is a need to recover the phytonutrients using green, sustainable and efficient solvents that are safe for human consumption. This work discusses ethyl lactate as a safe, green, efficient and potentially cheap solvent to recover phytonutrients from fruit and vegetable by-products. Ethyl lactate is compared with other organic solvents commonly used from the aspects of safety, environmental impacts and efficiency. Current challenges when employing ethyl lactate are also discussed. 相似文献
49.
50.
Jing Yang Changqing Liu Linxia Zhang Yanhui Liu Aihua Guo Huiwu Shi Xiaoxia Liu Ying Cheng 《Inflammation》2015,38(4):1415-1423