全文获取类型
收费全文 | 1852篇 |
免费 | 159篇 |
国内免费 | 204篇 |
专业分类
2215篇 |
出版年
2024年 | 7篇 |
2023年 | 36篇 |
2022年 | 90篇 |
2021年 | 101篇 |
2020年 | 78篇 |
2019年 | 105篇 |
2018年 | 92篇 |
2017年 | 50篇 |
2016年 | 80篇 |
2015年 | 137篇 |
2014年 | 159篇 |
2013年 | 154篇 |
2012年 | 173篇 |
2011年 | 152篇 |
2010年 | 88篇 |
2009年 | 82篇 |
2008年 | 94篇 |
2007年 | 75篇 |
2006年 | 80篇 |
2005年 | 54篇 |
2004年 | 41篇 |
2003年 | 36篇 |
2002年 | 48篇 |
2001年 | 22篇 |
2000年 | 32篇 |
1999年 | 16篇 |
1998年 | 12篇 |
1997年 | 18篇 |
1996年 | 14篇 |
1995年 | 20篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有2215条查询结果,搜索用时 0 毫秒
51.
52.
Zhang Xiaomei Zhang Dong Zhu Jiafen Liu Wang Xu Guoqiang Zhang Xiaojuan Shi Jinsong Xu Zhenghong 《Journal of industrial microbiology & biotechnology》2019,46(6):883-885
Journal of Industrial Microbiology & Biotechnology - Unfortunately, the order of the figures 1-4 has been positioned wrongly in the print published article 相似文献
53.
Ran Zuo Aline de Oliveira Enrica Bullita Maria Ines Torino Kaylie A. Padgett-Pagliai Christopher L. Gardner Natalie A. Harrison Danilo da Silva Marcelo L. Merli Claudio F. Gonzalez Graciela L. Lorca 《Environmental microbiology》2019,21(12):4822-4835
Liberibacter asiaticus is the prevalent causative pathogen of Huanglongbing or citrus greening disease, which has resulted in a devastating crisis in the citrus industry. A thorough understanding of this pathogen's physiology and mechanisms to control cell survival is critical in the identification of therapeutic targets. YbeY is a highly conserved bacterial RNase that has been implicated in multiple roles. In this study, we evaluated the biochemical characteristics of the L. asiaticus YbeY (CLIBASIA_01560) and assessed its potential as a target for antimicrobials. YbeYLas was characterized as an endoribonuclease with activity on 3′ and 5′ termini of 16S and 23S rRNAs, and the capacity to suppress the E. coli ΔybeY phenotype. We predicted the YbeYLas protein:ligand interface and subsequently identified a flavone compound, luteolin, as a selective inhibitor. Site-directed mutagenesis was subsequently used to identify key residues involved in the catalytic activity of YbeYLas. Further evaluation of naturally occurring flavonoids in citrus trees indicated that both flavones and flavonols had potent inhibitory effects on YbeYLas. Luteolin was subsequently examined for efficacy against L. asiaticus in Huanglongbing-infected citrus trees, where a significant reduction in L. asiaticus gene expression was observed. 相似文献
54.
55.
Cloning, sequence analysis and identification of a nonsense mutation-mediated mRNA decay of porcine GSTM2 gene 总被引:2,自引:0,他引:2
Huang J Xiong Y Deng C Zuo B Xu D Lei M Jiang S 《Acta biochimica et biophysica Sinica》2007,39(8):560-566
The glutathione S-transferase mu 2 gene (GSTM2) encodes a GST functioning in the elimination of electrophilic compounds and the regulation of cell growth. In this study, the sequence of porcine GSTM2 gene that contains the complete sequence encoding a protein of 218 amino acids was cloned. The deduced amino acid sequence shared 76%, 78% and 76% identity with that of human, mouse and rat, respectively, mRNA expression analysis showed that the porcine GSTM2 gene was expressed at a high level in liver and testis, at a medium level in longissimus dorsi muscle, adipose tissue, spleen and lung, at a low level in kidney, and at a very low level in heart and embryo. A nonsense mutation (CGA→TGA) resulted from C27T substitution in the fifth exon to produce a premature translation termination codon was identified, and it was discovered that nonsense-mediated mRNA decay might have an effect on the regulation of porcine GSTM2 gene expression. This polymorphism was analyzed in Large White, Landrace, Meishan and Qingping pig populations using the Taq I-polymerase chain reaction-restriction fragment length polymorphism method. The result showed that allele C had a higher frequency than allele T in each population. 相似文献
56.
为了探讨我国西双版纳热带季雨林的能量分配和平衡问题,利用涡度相关系统和常规气象仪器的连续监测结果,分析了不同季节的能量通量特征和闭合特点。结果表明,西双版纳热带季雨林全年的净辐射、潜热通量、显热通量、土壤热通量和热储存量分别是4546.07、2453.24、492.22、-10.47和45.93 MJ/m^(2),土壤为热源,潜热年总值占净辐射的54.0%,显热占10.8%,能量以蒸发散为主要的耗损形式。辐射和能量有明显的日变化和季节动态,各能量分量的日变化几乎都呈白天高夜间低的单峰趋势,反照率整体为0.10~0.12,波动不大;波文比季节差异明显,为0~0.8。热带季雨林的全年闭合度为0.67,未考虑热储量时,闭合度为0.51~0.79,考虑热储量为0.53~0.80。可见,在林冠茂密的热带季雨林中,热储量对能量闭合度的贡献不大,忽略热储量并不是导致能量不闭合的主要原因。 相似文献
57.
Shuyu Xin Lingzhi Liu Yanling Li Jing Yang Lielian Zuo Pengfei Cao Qijia Yan Shen Li Li Yang Taimei Cui Jianhong Lu 《中国病毒学》2022,37(6):913-921
The AKT/mTOR and NF-κB signalings are crucial pathways activated in cancers including nasopharyngeal carcinoma (NPC), which is prevalent in southern China and closely related to Epstein-Barr virus (EBV) infection. How these master pathways are persistently activated in EBV-associated NPC remains to be investigated. Here we demonstrated that EBV-encoded latent membrane protein 1 (LMP1) promoted cyclophilin A (CYPA) expression through the activation of NF-κB. The depletion of CYPA suppressed cell proliferation and facilitated apoptosis. CYPA was able to bind to AKT1, thus activating AKT/mTOR/NF-κB signaling cascade. Moreover, the use of mTOR inhibitor, rapamycin, subverted the activation of the positive feedback loop, NF-κB/CYPA/AKT/mTOR. It is reasonable that LMP1 expression derived from initial viral infection is enough to assure the constant potentiation of AKT/mTOR and NF-κB signalings. This may partly explain the fact that EBV serves as a tumor-promoting factor with minimal expression of the viral oncoprotein LMP1 in malignancies. Our findings provide new insight into the understanding of causative role of EBV in tumorigenicity during latent infection. 相似文献
58.
Qi Zhang Shiyuan Wang Yi Pan Dongqing Su Qianzi Lu Yongchun Zuo Lei Yang 《Genomics》2019,111(5):1134-1141
Knowing the comprehensive knowledge about the protein subcellular localization is an important step to understand the function of the proteins. Recent advances in system biology have allowed us to develop more accurate methods for characterizing the proteins at subcellular localization level. In this study, the analysis method was developed to characterize the topological properties and biological properties of the cytoplasmic proteins, inner membrane proteins, outer membrane proteins and periplasmic proteins in Escherichia coli (E. coli). Statistical significant differences were found in all topological properties and biological properties among proteins in different subcellular localizations. In addition, investigation was carried out to analyze the differences in 20 amino acid compositions for four protein categories. We also found that there were significant differences in all of the 20 amino acid compositions. These findings may be helpful for understanding the comprehensive relationship between protein subcellular localization and biological function 相似文献
59.
60.