全文获取类型
收费全文 | 108143篇 |
免费 | 8389篇 |
国内免费 | 9040篇 |
专业分类
125572篇 |
出版年
2024年 | 241篇 |
2023年 | 1419篇 |
2022年 | 3263篇 |
2021年 | 5517篇 |
2020年 | 3783篇 |
2019年 | 4684篇 |
2018年 | 4434篇 |
2017年 | 3243篇 |
2016年 | 4597篇 |
2015年 | 6681篇 |
2014年 | 7856篇 |
2013年 | 8310篇 |
2012年 | 9992篇 |
2011年 | 8980篇 |
2010年 | 5555篇 |
2009年 | 4975篇 |
2008年 | 5715篇 |
2007年 | 5142篇 |
2006年 | 4465篇 |
2005年 | 3497篇 |
2004年 | 2970篇 |
2003年 | 2721篇 |
2002年 | 2276篇 |
2001年 | 1867篇 |
2000年 | 1694篇 |
1999年 | 1672篇 |
1998年 | 1037篇 |
1997年 | 1002篇 |
1996年 | 941篇 |
1995年 | 823篇 |
1994年 | 787篇 |
1993年 | 617篇 |
1992年 | 819篇 |
1991年 | 619篇 |
1990年 | 468篇 |
1989年 | 443篇 |
1988年 | 354篇 |
1987年 | 344篇 |
1986年 | 266篇 |
1985年 | 286篇 |
1984年 | 156篇 |
1983年 | 161篇 |
1982年 | 99篇 |
1981年 | 85篇 |
1980年 | 60篇 |
1979年 | 77篇 |
1977年 | 59篇 |
1975年 | 56篇 |
1974年 | 52篇 |
1973年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Li Yanman Qu Ying Wang Yang Bai Xue Tian Geng Liu Zhirou Li Yonghua Zhang Kaiming 《Molecular biology reports》2019,46(6):6027-6037
Molecular Biology Reports - Begonia semperflorens (B. semperflorens), belonging to the family Begoniaceae, has now been widely cultivated worldwide and is famous for its ornamental plants with... 相似文献
992.
Molecular Biology Reports - The complete genome sequence provides the opportunity for genome-wide and coding region analysis of SSRs in the king cobra and for cross-species identification of... 相似文献
993.
Zhu Yanji Li Qian Xun Wenlong Chen Yuan Zhang Caihui Sun Shuzhen 《Molecular biology reports》2019,46(4):3809-3816
Molecular Biology Reports - The purpose of our research is to elucidate whether oxLDL activates P2X7R in cultured human podocytes and if the activation of P2X7R leads to podocyte apoptosis.... 相似文献
994.
Mycopathologia - Candida albicans is one of the most important fungal pathogens. Hyphal development is required for the virulence of this pathogen. Our previous study has revealed that Spf1, an ER... 相似文献
995.
Dan Liu Xiaoxi Li Xintian Chen Yu Sun Anqun Tang Zhongwei Li Junnian Zheng Ming Shi 《生物化学与生物物理学报:癌评论》2019,1871(1):20-28
The treatment of cancer has made great progress. However, drug resistance remains problematic. Multiple physiologic processes of tumor development can be dominated by central and sympathetic nervous systems. The interactions between the nervous system, immune system, and tumor occur consistently and dynamically. Recent evidence suggests that nerves and neural signals are intimately involved in the development of resistance to cancer therapies. In this review, we will provide an overview of the recent progress in this rapidly growing area and discuss the potential new strategies for targeting the neural signaling pathway to improve the effectiveness of chemotherapies, targeted therapies, and immunotherapies. 相似文献
996.
Chen Lilin Chao Yufan Cheng Pengchao Li Na Zheng Hongnan Yang Yajuan 《Neurochemical research》2019,44(8):1950-1963
Neurochemical Research - As a reductive gas, hydrogen plays an antioxidant role by selectively scavenging oxygen free radicals. It has been reported that hydrogen has protective effects against... 相似文献
997.
Neurochemical Research - A majority of excitatory synapses in the brain are localized on the dendritic spines. Alterations of spine density and morphology are associated with many neurological... 相似文献
998.
The structural, elastic and electronic properties of Co7M6 (M?=?W, Mo, Nb) μ phases were investigated by first-principles calculations based on the density functional theory (DFT). The calculated cohesive energy indicates that Co7M6 (M?=?W, Mo, Nb) μ phases are thermodynamically stable. Besides, Co7W6 owns a higher structural stability than that of Co7Mo6 and Co7Nb6. The obtained elastic constant demonstrates that Co7M6 (M?=?W, Mo, Nb) are mechanically stable. With Voigt-Reuss-Hill (VRH) approximation, the elastic bulk modulus (B), shear modulus (G), Young's modulus (E) and Poisson's ratio (ν) were derived. The ductility and plasticity as well as the elastic anisotropy of the three phases were discussed in details. Finally, the density of states and charge density difference were also analysed to reveal the underlying mechanism of structural stability and the elastic properties. 相似文献
999.
Shenwei Zhang Yiqiang Yuan Zheng Zhang Jing Guo Jing Li Kui Zhao 《Bioscience, biotechnology, and biochemistry》2019,83(4):653-658
Doxorubicin (Dox) is an anthracycline antibiotic that has been used to treat different cancers. Dox-induced cardiotoxicity is common in clinical practice, while its mechanism is unknown. It has been proved that lncRNA FOXC2-AS1 may promote doxorubicin resistance and WNT1-inducible signaling pathway protein-1 (WISP1) blocks doxorubicin-induced cardiomyocyte death. Our study aimed to investigate the involvement of lncRNA FOXC2-AS1 and WISP1 in doxorubicin-induced cardiotoxicity and to explore their interactions. In our study we observed that FOXC2-AS1 and WISP1 mRNA were downregulated in heart tissues of mice with Dox-induced cardiotoxicity. FOXC2-AS1 and WISP1 mRNA expression were positively correlated in mice with Dox-induced cardiotoxicity but not in healthy mice. Overexpression of FOXC2-AS1 promoted to viability of mice cardiomyocytes under Dox treatment and also increased the expression level of WISP1. In contrast, WISP1 overexpression showed no significant effect on FOXC2-AS1. We therefore conclude that lncRNA FOXC2-AS1 may upregulate WISP1 to protect cardiomyocytes from doxorubicin-induced cardiotoxicity. 相似文献
1000.
Ji-Gang Zhang Dan-Dan Zhang Ying Liu Juan-Ni Hu Xue Zhang Li Li Wan Mu Guan-Hua Zhu Qin Li Gao-Lin Liu 《生物化学与生物物理学报:疾病的分子基础》2019,1865(6):1113-1125
Vasculogenic mimicry (VM) results in the formation of an alternative circulatory system that can improve the blood supply to multiple malignant tumors, including hepatocellular carcinoma (HCC). However, the potential mechanisms of RhoC/ROCK in VM have not yet been investigated in HCC. Here, RhoC expression was upregulated in HCC tissues, especially the VM-positive (VM+) group, compared to noncancerous tissues (P < 0.01), and patients with high expression of RhoC had shorter survival times (P < 0.001). The knockdown of RhoC via short hairpin RNA (shRNA) in SK-Hep-1 cells significantly decreased VM formation and cell motility. In contrast, cell motility and VM formation were remarkably enhanced when RhoC was overexpressed in HepG2 cells. To further assess the potential role of ROCK1 and ROCK2 on VM, we stably knocked down ROCK1 or ROCK2 in MHCC97H cells. Compared to ROCK1 shRNA, ROCK2 shRNA could largely affect VM formation, cell motility and the key VM factors, as well as the epithelial-mesenchymal transition (EMT) markers in vitro and in vivo. Moreover, p-ERK, p-MEK, p-FAK, p-paxillin, MT1-MMP and MMP2 levels were clearly altered following the overexpression of RhoC, but ROCK2 shRNA had little effect on the expression of p-FAK, which indicated that RhoC regulates FAK/paxillin signaling, but not through ROCK2. In conclusion, our results show that RhoC/ROCK2 may have a major effect on VM in HCC via ERK/MMPs signaling and might be a potential therapeutic target for the treatment of HCC. 相似文献