全文获取类型
收费全文 | 67728篇 |
免费 | 7015篇 |
国内免费 | 4554篇 |
专业分类
耳鼻咽喉 | 626篇 |
儿科学 | 1015篇 |
妇产科学 | 764篇 |
基础医学 | 7350篇 |
口腔科学 | 1330篇 |
临床医学 | 9030篇 |
内科学 | 9539篇 |
皮肤病学 | 599篇 |
神经病学 | 3300篇 |
特种医学 | 2438篇 |
外国民族医学 | 34篇 |
外科学 | 6276篇 |
综合类 | 12463篇 |
现状与发展 | 15篇 |
一般理论 | 17篇 |
预防医学 | 5645篇 |
眼科学 | 1747篇 |
药学 | 7480篇 |
69篇 | |
中国医学 | 4129篇 |
肿瘤学 | 5431篇 |
出版年
2024年 | 292篇 |
2023年 | 1131篇 |
2022年 | 2965篇 |
2021年 | 3693篇 |
2020年 | 2997篇 |
2019年 | 2204篇 |
2018年 | 2376篇 |
2017年 | 2260篇 |
2016年 | 2148篇 |
2015年 | 3328篇 |
2014年 | 3882篇 |
2013年 | 3725篇 |
2012年 | 5546篇 |
2011年 | 5698篇 |
2010年 | 3884篇 |
2009年 | 3135篇 |
2008年 | 3742篇 |
2007年 | 3759篇 |
2006年 | 3639篇 |
2005年 | 3317篇 |
2004年 | 2364篇 |
2003年 | 2274篇 |
2002年 | 1872篇 |
2001年 | 1243篇 |
2000年 | 1161篇 |
1999年 | 1174篇 |
1998年 | 707篇 |
1997年 | 741篇 |
1996年 | 567篇 |
1995年 | 568篇 |
1994年 | 454篇 |
1993年 | 297篇 |
1992年 | 347篇 |
1991年 | 333篇 |
1990年 | 281篇 |
1989年 | 208篇 |
1988年 | 171篇 |
1987年 | 161篇 |
1986年 | 133篇 |
1985年 | 104篇 |
1984年 | 88篇 |
1983年 | 43篇 |
1982年 | 45篇 |
1981年 | 33篇 |
1980年 | 24篇 |
1979年 | 27篇 |
1978年 | 12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 0 毫秒
1.
Qian Zhang Larry D. Mesner Gina M. Calabrese Naomi Dirckx Zhu Li Angela Verardo Qian Yang Robert J. Tower Marie-Claude Faugere Charles R. Farber Thomas L. Clemens 《The Journal of clinical investigation》2021,131(7)
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass. 相似文献
2.
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
3.
目的探讨雨课堂在临床流行病学教学中的作用和效果。方法采用随机对照法在本科阶段无流行病学学习经历的临床专业硕士研究生中,使用雨课堂线上课前预习及课后随堂练习的功能,用于评价雨课堂线上功能的辅助教学效果。结果应用雨课堂线上功能干预组与对照组在基线、阶段小测和末考卷面成绩均无统计学差异;但对于主动学习,雨课堂参与度较高的学生成绩提高明显。结论雨课堂有利于理论性较强课程的学习,但是仍不能忽略课堂教学师生互动过程。 相似文献
4.
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
5.
Jeffrey Buenaflor Parker Sommerville Hang Qian Christine Luscombe 《Macromolecular chemistry and physics.》2020,221(2)
A comparative study involving bimetallic nickel catalysts designed from disubstituted N,N,N′,N′‐tetra(diphenylphosphanylmethyl)benzene diamine bridging ligands is reported. Catalyst behavior is explored in the Kumada catalyst‐transfer polymerization (KCTP) using poly(3‐hexylthiophene) (P3HT) as the model system. The success of a controlled polymerization is monitored by analyzing monomer conversion, degree of polymerization, end‐group identity, and molecular weight distribution. The characterization of P3HT obtained from KCTP initiated with the bimetallic catalysts shows chain‐growth behavior; however, the presence of Br/Br end‐groups and broader molecular weight distribution reveals a reduced controlled polymerization compared to the commonly employed Ni(dppp)Cl2. The observed increase in intermolecular chain transfer and termination processes in KCTP initiation with the bimetallic catalysts can be attributed to a weaker Ni(0)‐π‐aryl complex interaction, which is caused by increased steric crowding of the coordination sphere. 相似文献
6.
7.
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)
8.
9.
Platelet function has been described by many laboratory assays, and PL-11 is a new point-of-care platelet function analyzer based on platelet count drop method, which counts platelet before and after the addition of agonists in the citrated whole blood samples. The present study sought to compare PL-11 with other three major more established assays, light transmission aggregometry (LTA), VerifyNow? aspirin system and thromboelastography (TEG), for monitoring the short-term aspirin responses in healthy individuals. Ten healthy young men took 100?mg/d aspirin for 3-day treatment. Platelet function was measured via PL-11, LTA, VerifyNow and TEG, respectively. The blood samples were collected at baseline, 2 hour, 1 day during the aspirin treatment and 1 day, 5?±?1 days, 8?±?1 days after the aspirin withdrawal. Moreover, 90 additional healthy subjects were recruited to establish a reference range for PL-11. Platelet function of healthy subjects decreased significantly 2 hours after 100?mg/d aspirin intake and began to recover during 4–6 days after the aspirin withdrawal. Correlations between methods were PL-11 vs. LTA (r?=?0.614, p?<?0.01); PL-11 vs. VerifyNow (r?=?0.829, p?<?0.01); PL-11 vs. TEG (r?=?0.697, p?<?0.001). There was no significant bias between PL-11 and LTA at baseline (bias?=?1.94%, p?=?0.804) using Bland-Altman analysis, while the data of PL-11 were significantly higher than LTA (bias?=?24.02%, p?<?0.001) during the aspirin therapy. The reference range for PL-11 in healthy young individuals was from 66.8 to 90.5% (95%CI). When aspirin low-responsiveness was defined as LTA?>?20%, the cut-off values for each method were, respectively: PL-11?>?50%, VerifyNow?>?533 ARU, TEG?>?60.2%. The results of different platelet function assays were uninterchangeable for monitoring aspirin response and correlations among them were also varied. Correlations among PL-11 and other three major assays suggested the ability of PL-11 to assess the treatment effects of aspirin. But a large cohort study is needed to confirm the cut-off value of aspirin response detected by PL-11. 相似文献
10.