全文获取类型
收费全文 | 62476篇 |
免费 | 5535篇 |
国内免费 | 2633篇 |
专业分类
电工技术 | 3377篇 |
技术理论 | 6篇 |
综合类 | 4131篇 |
化学工业 | 10517篇 |
金属工艺 | 3936篇 |
机械仪表 | 4005篇 |
建筑科学 | 4692篇 |
矿业工程 | 2224篇 |
能源动力 | 2019篇 |
轻工业 | 3664篇 |
水利工程 | 1098篇 |
石油天然气 | 4575篇 |
武器工业 | 462篇 |
无线电 | 6696篇 |
一般工业技术 | 7293篇 |
冶金工业 | 3370篇 |
原子能技术 | 792篇 |
自动化技术 | 7787篇 |
出版年
2024年 | 601篇 |
2023年 | 1108篇 |
2022年 | 1801篇 |
2021年 | 2483篇 |
2020年 | 1915篇 |
2019年 | 1692篇 |
2018年 | 1908篇 |
2017年 | 2107篇 |
2016年 | 1905篇 |
2015年 | 2409篇 |
2014年 | 3046篇 |
2013年 | 3511篇 |
2012年 | 3670篇 |
2011年 | 4024篇 |
2010年 | 3687篇 |
2009年 | 3321篇 |
2008年 | 3266篇 |
2007年 | 3219篇 |
2006年 | 3210篇 |
2005年 | 2770篇 |
2004年 | 2047篇 |
2003年 | 2156篇 |
2002年 | 2483篇 |
2001年 | 2081篇 |
2000年 | 1615篇 |
1999年 | 1707篇 |
1998年 | 1255篇 |
1997年 | 1075篇 |
1996年 | 1111篇 |
1995年 | 847篇 |
1994年 | 637篇 |
1993年 | 470篇 |
1992年 | 366篇 |
1991年 | 275篇 |
1990年 | 206篇 |
1989年 | 169篇 |
1988年 | 155篇 |
1987年 | 89篇 |
1986年 | 69篇 |
1985年 | 37篇 |
1984年 | 39篇 |
1983年 | 29篇 |
1982年 | 25篇 |
1981年 | 15篇 |
1980年 | 22篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Shuailong Zheng Li Li Helin Zhou Xujia Zhang Xiaoli Xu Dinghui Dai Siyuan Zhan Jiaxue Cao Jiazhong Guo Tao Zhong Linjie Wang Hongping Zhang 《International journal of molecular sciences》2022,23(21)
The proliferation and differentiation of mammalian skeletal muscle satellite cells (MuSCs) are highly complicated. Apart from the regulatory signaling cascade driven by the protein-coding genes, non-coding RNAs such as microRNAs (miRNA) and circular RNAs (circRNAs) play essential roles in this biological process. However, circRNA functions in MuSCs proliferation and differentiation remain largely to be elucidated. Here, we screened for an exonic circTCF4 based on our previous RNA-Seq data, specifically expressed during the development of the longest dorsal muscle in goats. Subsequently, the circular structure and whole sequence of circTCF4 were verified using Sanger sequencing. Besides, circTCF4 was spatiotemporally expressed in multiple tissues from goats but strikingly enriched in muscles. Furthermore, circTCF4 suppressed MuSCs proliferation and differentiation, independent of AGO2 binding. Finally, we conducted Poly(A) RNA-Seq using cells treated with small interfering RNA targeting circTCF4 and found that circTCF4 would affect multiple signaling pathways, including the insulin signaling pathway and AMPK signaling pathway related to muscle differentiation. Our results provide additional solid evidence for circRNA regulating skeletal muscle formation. 相似文献
62.
63.
Yu Xiao Mengjuan Li Xiaoyi Guo Hui Zeng Xuehong Shuai Jianhua Guo Qingzhou Huang Yuefeng Chu Bo Zhou Jake Wen Jun Liu Hanwei Jiao 《International journal of molecular sciences》2022,23(21)
Brucellosis is a severe zoonotic infectious disease caused by the infection of the Brucella, which is widespread and causes considerable economic losses in underdeveloped areas. Brucella is a facultative intracellular bacteria whose main target cells for infection are macrophages, placental trophoblast cells and dendritic cells. The main clinical signs of Brucella infection in livestock are reproductive disorders and abortion. At present, the pathogenesis of placentitis or abortion caused by Brucella in livestock is not fully understood, and further research on the effect of Brucella on placental development is still necessary. This review will mainly introduce the research progress of Brucella infection of placental trophoblast cells as well as the inflammatory response caused by it, explaining the molecular regulation mechanism of Brucella leading to reproductive system disorders and abortion, and also to provide the scientific basis for revealing the pathogenesis and infection mechanism of Brucella. 相似文献
64.
Yue Wang Yangyu Li Wei Guo Xiao Yang Jiameng Qu Mang Gao Shuting Chen Jiangru Dong Qing Li Tiejie Wang 《International journal of molecular sciences》2022,23(22)
To clarify the differences in the clinical application scope of Chrysanthemum morifolium flower (CMF) and Chrysanthemum indicum flower (CIF), two herbs of similar origin, an integrated strategy of network pharmacology, molecular pharmacology, and metabolomics was employed, with a view to investigating the commonalities and dissimilarities in chemical components, efficacy and mechanisms of action. Initial HPLC-Q-TOF-MS analysis revealed that CMF and CIF had different flavonoid constituents. The biological processes underlying the therapeutic effects of CMF and CIF on liver-fire hyperactivity syndrome of hypertension (LFHSH) were predicted to be related to inflammatory response, fatty acid production, and other pathways based on network pharmacology analysis. ELISA, molecular docking, Western blot, and metabolomics techniques showed similar effects of CMF and CIF in lowering blood pressure, resistance to tissue, organ and functional damage, and dyslipidemia. However, distinct effects were found in the regulation of inflammatory response, PI3K-Akt and NF-κB signaling pathways, lipid anabolism, renin-angiotensin system, and metabolic abnormalities. The comparable efficacies of CMF and CIF, despite having distinct mechanisms of action, may be attributed to the integration and counteraction of their different regulating capabilities on the above anti-LFHSH mechanisms. This study offers a vital platform for assessment of differential and precise applications of herbs of close origin with similar but slightly different medicinal properties, and provides a research strategy for bridging Chinese medicine and modern precision medicine. 相似文献
65.
Lan Wang Kai Xu Ningdan Wang Linke Ding Wenyu Zhao Ruyan Wan Weiming Zhao Xiaoshu Guo Xin Pan Juntang Yang Ivan Rosas Guoying Yu 《International journal of molecular sciences》2022,23(22)
Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and fatal interstitial lung disease with unknown etiology. Despite substantial progress in understanding the pathogenesis of pulmonary fibrosis and drug development, there is still no cure for this devastating disease. Fenbendazole (FBZ) is a benzimidazole compound that is widely used as an anthelmintic agent and recent studies have expanded the scope of its pharmacological effects and application prospect. This study demonstrated that FBZ treatment blunted bleomycin-induced lung fibrosis in mice. In vitro studies showed that FBZ inhibited the proliferation and migration of human embryo lung fibroblasts. Further studies showed that FBZ significantly inhibited glucose consumption, moderated glycolytic metabolism in fibroblasts, thus activated adenosine monophosphate-activated protein kinase (AMPK), and reduced the activation of the mammalian target of rapamycin (mTOR) pathway, thereby inhibiting transforming growth factor-β (TGF-β1)-induced fibroblast-to-myofibroblast differentiation and collagen synthesis. In summary, our data suggested that FBZ has potential as a novel treatment for pulmonary fibrosis. 相似文献
66.
67.
Xinyu Wang Hutailong Zhu Jiayin Hu Haobin Li Suhan Guo Bin Chen Changxiao Liu Guangji Wang Fang Zhou 《International journal of molecular sciences》2022,23(21)
Nephrotoxicity is the dose-limiting factor of cisplatin treatment. Magnesium isoglycyrrhizinate (MgIG) has been reported to ameliorate renal ischemia–reperfusion injury. This study aimed to investigate the protective effect and possible mechanisms of MgIG against cisplatin-induced nephrotoxicity from the perspective of cellular pharmacokinetics. We found that cisplatin predominantly accumulated in mitochondria of renal tubular epithelial cells, and the amount of binding with mitochondrial DNA (mtDNA) was more than twice that with nuclear DNA (nDNA). MgIG significantly lowered the accumulation of cisplatin in mitochondria and, in particular, the degree of target-binding to mtDNA. MgIG notably ameliorated cisplatin-induced changes in mitochondrial membrane potential, morphology, function, and cell viability, while the magnesium donor drugs failed to work. In a mouse model, MgIG significantly alleviated cisplatin-caused renal dysfunction, pathological changes of renal tubules, mitochondrial ultrastructure variations, and disturbed energy metabolism. Both in vitro and in vivo data showed that MgIG recovered the reduction of NAD+-related substances and NAD+-dependent deacetylase sirtuin-3 (SIRT3) level caused by cisplatin. Furthermore, SIRT3 knockdown weakened the protective effect of MgIG on mitochondria, while SIRT3 agonist protected HK-2 cells from cisplatin and specifically reduced platinum-binding activity with mtDNA. In conclusion, MgIG reduces the target-binding amount of platinum to mtDNA and exerts a protective effect on cisplatin-induced renal injury through SIRT3, which may provide a new strategy for the treatment of cisplatin-induced nephrotoxicity. 相似文献
68.
69.
Kun Wang Qing Guo Zengkun Nie Huiyan Wang Jingshun Gao Jianqi Zhang Linfeng Yu Xia Guo Maojie Zhang 《International journal of molecular sciences》2022,23(17)
We designed and synthesized an asymmetric non-fullerene small molecule acceptor (NF-SMA) IDT-TNIC with an A–D–π–A structure, based on an indacenodithiophene (IDT) central core, with a unidirectional non-fused alkylthio-thiophene (T) π-bridge, and 2-(3-oxo-2,3-dihydro-1H-cyclopenta[b]naphthalen-1-ylidene)malononitrile (NIC) extended terminal groups. IDT-TNIC molecules still maintain a good coplanar structure, which benefits from the non-covalent conformational locks (NCL) between O···S and S···S. The asymmetric structure increases the molecular dipole moment, and the extended terminal group broadens the absorption of the material, resulting in an excellent photovoltaic performance of IDT-TNIC. The photovoltaic device, based on PBDB-T:IDT-TNIC, exhibits an energetic PCE of 11.32% with a high Voc of 0.87 V, high Jsc of 19.85 mA cm−2, and a low energy loss of 0.57 eV. More importantly, IDT-TNICs with asymmetric structures show a superior property compared to symmetric IDT-Ns. The results demonstrate that it is an effectual strategy to enhance the properties of asymmetric A–D–π–A-based NF-SMAs with non-fused NCL π-bridges and extended terminal groups. 相似文献
70.