全文获取类型
收费全文 | 37390篇 |
免费 | 3022篇 |
国内免费 | 222篇 |
出版年
2023年 | 201篇 |
2022年 | 331篇 |
2021年 | 679篇 |
2020年 | 466篇 |
2019年 | 496篇 |
2018年 | 717篇 |
2017年 | 624篇 |
2016年 | 1025篇 |
2015年 | 1701篇 |
2014年 | 1650篇 |
2013年 | 2201篇 |
2012年 | 2676篇 |
2011年 | 2536篇 |
2010年 | 1567篇 |
2009年 | 1402篇 |
2008年 | 2150篇 |
2007年 | 2016篇 |
2006年 | 1911篇 |
2005年 | 1760篇 |
2004年 | 1691篇 |
2003年 | 1502篇 |
2002年 | 1429篇 |
2001年 | 845篇 |
2000年 | 785篇 |
1999年 | 724篇 |
1998年 | 369篇 |
1997年 | 291篇 |
1996年 | 269篇 |
1995年 | 317篇 |
1994年 | 258篇 |
1993年 | 211篇 |
1992年 | 440篇 |
1991年 | 451篇 |
1990年 | 370篇 |
1989年 | 354篇 |
1988年 | 332篇 |
1987年 | 296篇 |
1986年 | 273篇 |
1985年 | 281篇 |
1984年 | 232篇 |
1983年 | 193篇 |
1982年 | 166篇 |
1981年 | 197篇 |
1980年 | 153篇 |
1979年 | 192篇 |
1978年 | 183篇 |
1977年 | 160篇 |
1976年 | 150篇 |
1975年 | 154篇 |
1974年 | 147篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
The succinate dehydrogenase consists of only four subunits, all nuclearly encoded, and is part of both the respiratory chain and the Krebs cycle. Mutations in the four genes encoding the subunits of the mitochondrial respiratory chain succinate dehydrogenase have been recently reported in human and shown to be associated with a wide spectrum of clinical presentations. Although a comparatively rare deficiency in human, molecularly defined succinate dehydrogenase deficiency has already been found to cause encephalomyopathy in childhood, optic atrophy or tumor in adulthood. Because none of the typical housekeeping genes encoding this respiratory chain complex is known to present tissue-specific isoforms, the tissue-specific involvement represents a quite intriguing question, which is mostly addressed in this review. A differential impairment of electron flow through the respiratory chain, handling of oxygen, and/or metabolic blockade possibly associated with defects in the different subunits that can be advocated to account for tissue-specific involvement is discussed. 相似文献
14.
15.
About the specificity of photoinduced affinity labeling of Escherichia coli ribosomes by dihydrorosaramicin, a macrolide related to erythromycin 总被引:1,自引:0,他引:1
Photoactivation of the [3H]dihydrorosaramicin chromophore at a wavelength above 300 nm allows the covalent attachment of the macrolide antibiotic to the bacterial ribosome. Bidimensional electrophoresis shows that the radioactivity is mainly associated with proteins L1, L5, L6, L15, L18, L19, S1, S3, S4, S5 and S9. When photoincorporation of the drug is conducted in the presence of puromycin as effector of [3H]dihydrorosaramicin-binding sites, a decrease in the labeling of most proteins is observed, except for L18 and L19, which are radiolabeled to a larger extent. These results allow us to speculate that L18 and L19 belong to the high-affinity binding site of rosaramicin antibiotic. 相似文献
16.
Olsvik Ørjan Myhre Stein Berdal Bjorn P. Fossum Kåre 《Acta veterinaria Scandinavica》1982,23(2):204-210
Enterotoxigenic reference strains of Staphylococcus aureus were cultivated in sterile whole and skim milk for 18 h at 37°G. Staphylococcal enterotoxin A, B, and C were detected directly in the milk by an enzyme linked immunosorbent assay (ELISA), sensitive down to 1 ng/ml. Enterotoxins in the range of 1 ng–20 µg/ml milk were detected without any concentration or extraction. Skim and whole milk were almost identical as medium for enterotoxin production. 相似文献
17.
18.
Shashank Hambarde Chi-Lin Tsai Raj K. Pandita Albino Bacolla Anirban Maitra Vijay Charaka Clayton R. Hunt Rakesh Kumar Oliver Limbo Remy Le Meur Walter J. Chazin Susan E. Tsutakawa Paul Russell Katharina Schlacher Tej K. Pandita John A. Tainer 《Molecular cell》2021,81(14):2989-3006.e9
- Download : Download high-res image (222KB)
- Download : Download full-size image
19.
Xiaozhong Huang Yujuan Shi Hongjin Chen Rongrong Le Xiaohua Gong Ke Xu Qihan Zhu Feixia Shen Zimiao Chen Xuemei Gu Xiaojun Chen Xiong Chen 《Cell death & disease》2020,11(12)
Diabetic nephropathy (DN) as a global health concern is closely related to inflammation and oxidation. Isoliquiritigenin (ISL), a natural flavonoid compound, has been demonstrated to inhibit inflammation in macrophages. Herein, we investigated the effect of ISL in protecting against the injury in STZ-induced type 1 DN and in high glucose-induced NRK-52E cells. In this study, it was revealed that the administration of ISL not only ameliorated renal fibrosis and apoptosis, but also induced the deterioration of renal function in diabetic mice. Mediated by MAPKs and Nrf-2 signaling pathways, respectively, upstream inflammatory response and oxidative stress were neutralized by ISL in vitro and in vivo. Moreover, as further revealed by the results of molecular docking, sirtuin 1 (SIRT1) binds to ISL directly, and the involvement of SIRT1 in ISL-mediated renoprotective effects was confirmed by studies using in vitro models of SIRT1 overexpression and knockdown. In summary, by reducing inflammation and oxidative stress, ISL has a significant pharmacological effect on the deterioration of DN. The benefits of ISL are associated with the direct binding to SIRT1, the inhibition of MAPK activation, and the induction of Nrf-2 signaling, suggesting the potential of ISL for DN treatment.Subject terms: Pharmacology, Molecular biology 相似文献
20.
Corine Vialas Geneviève Pratviel Jean Bernadou Bernard Meunier 《Nucleosides, nucleotides & nucleic acids》2013,32(4-5):1061-1063
Abstract Mn TMPyP in the presence of sulfite/O2 catalyses the oxidation of dG into dIz as selectively but slower and less efficiently than in the presence of KHSO5. 相似文献