全文获取类型
收费全文 | 10387篇 |
免费 | 869篇 |
国内免费 | 272篇 |
出版年
2024年 | 5篇 |
2023年 | 63篇 |
2022年 | 59篇 |
2021年 | 294篇 |
2020年 | 215篇 |
2019年 | 282篇 |
2018年 | 351篇 |
2017年 | 308篇 |
2016年 | 481篇 |
2015年 | 672篇 |
2014年 | 774篇 |
2013年 | 768篇 |
2012年 | 996篇 |
2011年 | 955篇 |
2010年 | 602篇 |
2009年 | 521篇 |
2008年 | 644篇 |
2007年 | 593篇 |
2006年 | 507篇 |
2005年 | 450篇 |
2004年 | 391篇 |
2003年 | 351篇 |
2002年 | 322篇 |
2001年 | 136篇 |
2000年 | 107篇 |
1999年 | 100篇 |
1998年 | 88篇 |
1997年 | 57篇 |
1996年 | 51篇 |
1995年 | 50篇 |
1994年 | 39篇 |
1993年 | 32篇 |
1992年 | 27篇 |
1991年 | 38篇 |
1990年 | 26篇 |
1989年 | 28篇 |
1988年 | 15篇 |
1987年 | 11篇 |
1986年 | 18篇 |
1985年 | 25篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1976年 | 4篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1969年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Upon tumour necrosis factor alpha (TNFα) stimulation, cells respond actively by way of cell survival, apoptosis or programmed necrosis. The receptor‐interacting proteins 1 (RIP1) and 3 (RIP3) are responsible for TNFα‐mediated programmed necrosis. To delineate the differential contributions of RIP3 and RIP1 to programmed necrosis, L929 cells were stimulated with TNFα, carbobenzoxy‐valyl‐alanyl‐aspartyl‐[O‐methyl]‐fluoromethylketone (zVAD) or zVAD along with TNFα following RNA interference against RIP1 and RIP3, respectively. RIP1 silencing did not protect cells from TNFα‐mediated cell death, while RIP3 down‐regulation made them refractory to TNFα. The heat shock protein 90 inhibitor geldanamycin (GA) down‐regulated both RIP1 and RIP3 expression, which rendered cells resistant to zVAD/TNFα‐mediated cell death but not to TNFα‐mediated cell death alone. Therefore, the protective effect of GA on zVAD/TNFα‐stimulated necrosis might be attributed to RIP3, not RIP1, down‐regulation. Pretreatment of L929 cells with rapamycin mitigated zVAD‐mediated cell death, while the autophagy inhibitor chloroquine did not affect necrotic cell death. Meanwhile, necrotic cell death by zVAD and TNFα was caused by reactive oxygen species generation and effectively diminished by lipid‐soluble butylated hydroxyanisole. Taken together, the results indicate that RIP1 and RIP3 can independently mediate death signals being transduced by two different death stimuli, zVAD and TNFα. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
2.
Brucella cell surface protein (BCSP31) is potentially useful for diagnosing brucellosis. We aimed to establish a monoclonal antibody
(MAb) against Brucella melitensis BCSP31 and to investigate its distribution in diagnosis. Soluble recombinant BCSP31 was successfully expressed and purified.
Two MAbs (1F1 and 1E5) against B. melitensis BCSP31, effective in detecting both recombinant and cellular proteins, were obtained and characterized. The MAbs did not
react with Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Mycobacterium tuberculosis, or Bacillus aeruginosus, but strongly reacted with BCSP31 and B. melitensis by ELISA and Western blot analysis. We also tested different Brucella species and brucellosis using the prepared anti-BCSP31 MAbs. BCSP31 and anti-BCSP31 MAbs may play important roles in future
research in diagnosing brucellosis. 相似文献
3.
Uncoordinated 51-like kinase 2 (ULK2), a member of the serine/threonine kinase family, plays an essential role in the regulation of autophagy in mammalian cells. Given the role of autophagy in normal cellular homeostasis and in multiple diseases, improved mechanistic insight into this process may result in the development of novel therapeutic approaches. Here, we present evidence that ULK2 associates with karyopherin beta 2 (Kapβ2) for its transportation into the nucleus. We identify a potential PY-NLS motif (774gpgfgssppGaeaapslRyvPY795) in the S/P space domain of ULK2, which is similar to the consensus PY-NLS motif (R/K/H)X
2–5PY. Using a pull-down approach, we observe that ULK2 interacts physically with Kapβ2 both in vitro and in vivo. Confocal microscopy confirmed the co-localization of ULK2 and Kapβ2. Localization of ULK2 to the nuclear region was disrupted by mutations in the putative Kapβ2-binding motif (P794A). Furthermore, in transient transfection assays, the presence of the Kapβ2 binding site mutant (the cytoplasmic localization form) was associated with a substantial increase in autophagy activity (but a decrease in the in vitro serine-phosphorylation) compared with the wild type ULK2. Mutational analysis showed that the phosphorylation on the Ser1027 residue of ULK2 by Protein Kinase A (PKA) is the regulatory point for its functional dissociation from Atg13 and FIP 200, nuclear localization, and autophagy. Taken together, our observations indicate that Kapβ2 interacts with ULK2 through ULK2’s putative PY-NLS motif, and facilitates transport from the cytoplasm to the nucleus, depending on its Ser1027 residue phosphorylation by PKA, thereby reducing autophagic activity. 相似文献
4.
5.
Theoretical calculation of the sugar concentrations during enzymatic production of fructooligosaccharides 总被引:1,自引:0,他引:1
Summary In a batch production of fructooligosaccharides from sucrose, the concentrations of residual sucrose, glucose and fructooligosaccharides at a given reaction time(t) and initial sucrose concentration(S0) were theoretically calculated by the following correlation equations: Glucose(t) = 0.0653 S0 × ln(t); Fructooligosaccharides(t) = 0.1636 S0 × ln(t); Sucrose(t)=S0 - Glucose(t) + FOS(t). 相似文献
6.
In eukaryotes, small RNAs play important roles in both gene regulation and resistance to viral infection. Argonaute proteins have been identified as a key component of the effector complexes of various RNA-silencing pathways, but the mechanistic roles of Argonaute proteins in these pathways are not clearly understood. To address this question, we performed single-molecule fluorescence experiments using an RNA-induced silencing complex (core-RISC) composed of a small RNA and human Argonaute 2. We found that target binding of core-RISC starts at the seed region of the guide RNA. After target binding, four distinct reactions followed: target cleavage, transient binding, stable binding, and Argonaute unloading. Target cleavage required extensive sequence complementarity and accelerated core-RISC dissociation for recycling. In contrast, the stable binding of core-RISC to target RNAs required seed-match only, suggesting a potential explanation for the seed-match rule of microRNA (miRNA) target selection. [BMB Reports 2015; 48(12): 643-644] 相似文献
7.
Surface Plasmon Resonance Imaging-Based Protein Array Chip System for Monitoring a Hexahistidine-Tagged Protein during Expression and Purification 下载免费PDF全文
Hyeon-Su Ro Sun Ok Jung Byung Hoon Kho Hyung Pyo Hong Jae Sung Lee Yong-Beom Shin Min Gon Kim Bong Hyun Chung 《Applied microbiology》2005,71(2):1089-1092
A surface plasmon resonance imaging-based Ni2+-iminodiacetic acid-coated gold chip system was developed to enable specific detection of a hexahistidine-tagged recombinant protein in crude extracts or in column chromatography fractions. This system is especially advantageous for high-throughput analysis of multiple proteins. 相似文献
8.
9.
I. V. Goldenkova-Pavlova An. L. Piruzyan R. M. Abdeev L. V. Chripatch M. O. Radzhabov L. A. Piruzyan 《Russian Journal of Genetics》2006,42(8):942-946
Psoriasis, a multifactorial disease with genetic predisposition, has been used as an example to study the role of the ethnic background in multifactorial diseases in the Dagestan population. The individual information card (IIC) is proposed as the main tool for correct collection and processing of information. The results of the study demonstrate that the Dagestan population is a convenient and adequate model population for studying multifactorial diseases, such as psoriasis, and may serve as an object for studying the role of heredity in the etiologies and pathogeneses of this and other multifactorial diseases. 相似文献
10.
Jian-Ping An Rui-Rui Xu Xin Liu Jiu-Cheng Zhang Xiao-Fei Wang Chun-Xiang You Yu-Jin Hao 《The Plant journal : for cell and molecular biology》2021,106(5):1414-1430
Jasmonate (JA) induces the biosynthesis of anthocyanin and proanthocyanidin. MdMYB9 is essential for modulating the accumulation of both anthocyanin and proanthocyanidin in apple, but the molecular mechanism for induction of anthocyanin and proanthocyanidin biosynthesis by JA is unclear. In this study, we discovered an apple telomere-binding protein (MdTRB1) to be the interacting protein of MdMYB9. A series of biological assays showed that MdTRB1 acted as a positive modulator of anthocyanin and proanthocyanidin accumulation, and is dependent on MdMYB9. MdTRB1 interacted with MdMYB9 and enhanced the activation activity of MdMYB9 to its downstream genes. In addition, we found that the JA signaling repressor MdJAZ1 interacted with MdTRB1 and interfered with the interaction between MdTRB1 and MdMYB9, therefore negatively modulating MdTRB1-promoted biosynthesis of anthocyanin and proanthocyanidin. These results show that the JAZ1–TRB1–MYB9 module dynamically modulates JA-mediated accumulation of anthocyanin and proanthocyanidin. Taken together, our data further expand the functional study of TRB1 and provide insights for further studies of the modulation of anthocyanin and proanthocyanidin biosynthesis by JA. 相似文献