全文获取类型
收费全文 | 84778篇 |
免费 | 8809篇 |
国内免费 | 5706篇 |
专业分类
耳鼻咽喉 | 939篇 |
儿科学 | 1048篇 |
妇产科学 | 966篇 |
基础医学 | 8664篇 |
口腔科学 | 1738篇 |
临床医学 | 10767篇 |
内科学 | 11494篇 |
皮肤病学 | 726篇 |
神经病学 | 4010篇 |
特种医学 | 3291篇 |
外国民族医学 | 43篇 |
外科学 | 8440篇 |
综合类 | 16647篇 |
现状与发展 | 17篇 |
一般理论 | 18篇 |
预防医学 | 6847篇 |
眼科学 | 1877篇 |
药学 | 9672篇 |
99篇 | |
中国医学 | 5671篇 |
肿瘤学 | 6319篇 |
出版年
2024年 | 376篇 |
2023年 | 1445篇 |
2022年 | 3590篇 |
2021年 | 4519篇 |
2020年 | 3476篇 |
2019年 | 2669篇 |
2018年 | 2845篇 |
2017年 | 2746篇 |
2016年 | 2583篇 |
2015年 | 4079篇 |
2014年 | 4864篇 |
2013年 | 4813篇 |
2012年 | 7077篇 |
2011年 | 7342篇 |
2010年 | 5407篇 |
2009年 | 4517篇 |
2008年 | 5153篇 |
2007年 | 5167篇 |
2006年 | 4792篇 |
2005年 | 4110篇 |
2004年 | 3293篇 |
2003年 | 3108篇 |
2002年 | 2682篇 |
2001年 | 1756篇 |
2000年 | 1376篇 |
1999年 | 1051篇 |
1998年 | 619篇 |
1997年 | 636篇 |
1996年 | 495篇 |
1995年 | 442篇 |
1994年 | 395篇 |
1993年 | 259篇 |
1992年 | 281篇 |
1991年 | 226篇 |
1990年 | 227篇 |
1989年 | 139篇 |
1988年 | 126篇 |
1987年 | 114篇 |
1986年 | 86篇 |
1985年 | 72篇 |
1984年 | 71篇 |
1983年 | 29篇 |
1982年 | 26篇 |
1981年 | 26篇 |
1980年 | 18篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1974年 | 9篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 对比研究朝鲜淫羊藿酸性多糖酯化还原前后的理化特性,并探讨其改善油酸诱导的肝癌HepG2细胞脂质堆积活性的差异。方法 采用高效凝胶渗透色谱法测定朝鲜淫羊藿酸性多糖(EFPA)的均一性和分子量,高效液相色谱法测定EFPA和酯化还原后朝鲜淫羊藿酸性多糖(EFPA-R)的单糖组成;采用油酸(OA)处理HepG2细胞诱导建立脂质蓄积模型,不同浓度EFPA与EFPA-R(10、30、100、300 μg·mL-1)分别和OA共同作用于细胞24 h,采用CCK-8试剂盒测定细胞存活率,油红O染色观察细胞内脂滴蓄积情况,并采用试剂盒测定细胞内总胆固醇(TC)、甘油三酯(TG)含量。结果 EFPA为成分均一的多糖组分,分子量为125.8 kDa,由甘露糖、葡萄糖、半乳糖、葡萄糖醛酸和阿拉伯糖组成,摩尔比为1.7∶7.4∶1.4∶1.8∶1.0,葡萄糖占比最大,EFPA-R由甘露糖、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为0.8∶10.6∶2.1∶1.0;在10-300 μg·mL-1范围内,EFPA和EFPA-R对HepG2细胞的抑制作用较弱,作为给药浓度;与空白组相比,模型组细胞中TC、TG含量显著升高(P < 0.01),细胞内红色脂滴显著增多,与模型组相比,EFPA可显著降低细胞中TC、TG含量(P < 0.01),明显减少细胞内红色脂滴(P < 0.05或P < 0.01),EFPA-R干预后细胞则无明显变化。结论 EFPA可明显改善HepG2细胞脂质堆积情况,且呈现剂量依赖性,而半乳糖醛酸(GalA)的存在可能是其抑制HepG2细胞脂质蓄积的关键因素。 相似文献
2.
3.
Lei Yang You-Ling Shi Yan Ma Wei-Wei Ren Guang-Ming Pang Jiao Liu 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2022,130(1):43-52
Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis. 相似文献
4.
5.
Yinlei
Wen Huaguang Zhang Hanguang Su He Ren 《Optimal control applications & methods.》2020,41(4):1233-1250
In this article, a model-free off-policy reinforcement learning algorithm is applied to address the optimal tracking problem based on multiplayer non-zero-sum games for discrete-time linear systems. In contrast to the traditional method and the policy iteration method for solving the optimal tracking problems, the proposed algorithm operates with the system data rather than the knowledge of the system dynamics. For performing the proposed algorithm, an auxiliary augmented system is constructed via assembling the original system and the reference trajectory while a discount factor is introduced into the performance indexes. It is analyzed that the solutions of the proposed algorithm converge to the Nash equilibrium and the result is not influenced by the probing noise. Two simulations are presented to verify the feasibility and effectiveness of the proposed algorithm. 相似文献
6.
Xin Yi Wong Andrew Qi Jun Lim Qianyu Shen John Whay Kuang Chia Min Hoe Chew Wah Siew Tan 《Current medical research and opinion》2020,36(10):1677-1686
Abstract
Objective
Ras wild-type metastatic colorectal cancers (mCRC) may be treated with anti-vascular endothelial growth factor (VEGF) or anti-epidermal growth factor receptor (EGFR) agents. We aim to estimate patients’ preferences for mCRC treatment and relative importance of cost, efficacy improvement, avoidance of side effects and therapy convenience, and relative uptake between profiles that resemble Bevacizumab (anti-VEGF) and Cetuximab (anti-EGFR), two commonly prescribed mCRC targeted therapies. 相似文献7.
8.
9.
Sophocarpine attenuates toll‐like receptor 4 in steatotic hepatocytes to suppress pro‐inflammatory cytokines synthesis
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
10.