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951.
952.
The posttranslational methylation of the α-N-terminal amino group of proteins was first documented over 40 years ago, but the functional significance of this modification has been underexplored relative to lysine and arginine methylation. Increasing reports implicates α-N-terminal methylation as a widespread and critical regulator of mitosis, chromatin interactions, DNA repair, and translation fidelity. Here, we summarize advances in the current understanding of protein α-N-terminal methylation biological functions and mechanisms across eukaryotic organisms. Also, we describe the recent literature on substrate recognition and the discovery of potent and selective inhibitors for protein N-terminal methyltransferases. Finally, we summarize the emergent crosstalk between α-N-terminal methylation and other N-terminal modifications. 相似文献
953.
954.
《Saudi Journal of Biological Sciences》2017,24(7):1538-1546
The plant cell responds to abiotic stress conditions by adjusting its cellular metabolism and various defensive mechanisms. Cellular metabolism involves changes in the cell cycle, in which the cell undergoes repeated rounds of endocycles leading to polyploidization. Defense mechanisms such as role of antioxidants are a key to understand plant adaptation. The present work describes endoreduplication and radical scavenging activity as two different defense mechanisms adapted by plants for their survival under stress condition. The work describes linkage of these two processes with each other under abiotic stress. Endoreduplicated root tip cells of Allium cepa were depolyploidized by exogenous phytohormones. Further, free radical scavenging activity from normal, endoreduplicated and depolyploidized root tips cells was observed to understand the role of phytohormones. Elevated free radical scavenging potential was observed in endoreduplicated cells compared to normal and depolyploidized cells. Based on these results, it was concluded that endoreduplication and antioxidant pathways are linked with each other through phytohormonal activities. The concentration of auxin and cytokinin regulates the activity of ascorbate oxidase enzyme, which in turn maintains the concentration of AsA within the cell. AsA level directs the prolyl-hydroxylation process of cell division proteins in quiescent center cells either toward endoreduplication process or cell division process. 相似文献
955.
956.
《Molecular & cellular proteomics : MCP》2020,19(11):1910-1920
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- •PRMT5 glutathionylation is increased in aged mice or under oxidative stress.
- •Deglutathionylation of PRMT5 is catalyzed by glutaredoxin-1.
- •PRMT5 glutathionylation decreases its methyltransferase activity.
- •PRMT5 glutathionylation results in G2/M arrest and inhibits cell proliferation.
957.
The authors are indedted to Mrs. Y. Miyazawa and Miss H. Koyama for their technical assistance. This work was supported in part by the research grant from the Ministry of Education. 相似文献
958.
Ujjaldeep Jaggi Siva Karthik Varanasi Siddheshvar Bhela Barry T. Rouse 《Microbes and infection / Institut Pasteur》2018,20(6):337-345
Ocular infection with herpes simplex virus (HSV) can result in a chronic immune inflammatory lesion that is a significant cause of human blindness. A key to controlling stromal keratitis (SK) lesion severity is to identify cellular and molecular events responsible for tissue damage and to counteract them. One potentially useful approach to achieve such therapy is Retinoic Acid (RA). Here we show that RA therapy reduces the severity of SK by having inhibitory effects on the T effector subtypes responsible for orchestrating SK. RA also served to stabilize the function of regulatory T cell (Treg) which counteract inflammatory cell activity. The Treg stabilizing effect was demonstrated by in vitro studies where RA was shown to retain Foxp3 expression when exposed to proinflammatory conditions such as IL-12 and IL-6+TGF-β. in vivo studies revealed that RA exerted its stabilizing effects by downregulating IL-6R expression on Treg after HSV-1 infection and this helped to control the progression of SK. Since the therapy was effective when used both early and after the initiation of lesions, it may represent a valuable means of therapy when used alone or along with additional therapies. 相似文献
959.
《Molecular cell》2021,81(23):4843-4860.e8
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960.
Florence Luttringer Etienne Mulliez Bernard Dublet David Lemaire Marc Fontecave 《Journal of biological inorganic chemistry》2009,14(6):923-933
Strict and facultative anaerobes depend on a class III ribonucleotide reductase for their growth. These enzymes are the sole
cellular catalysts for de novo biosynthesis of the deoxyribonucleotides needed for DNA chain elongation and repair. In its
active form, the class III ribonucleotide reductase from Escherichia coli contains a free radical located on the G681 residue which is essential for the activation of the ribonucleotide substrate
toward its reduction. The 3D structure of the homologous enzyme from bacteriophage T4 has revealed the presence of a metal
center bound to four conserved cysteine residues. In this report we identify the metal of the E. coli enzyme as Zn. We show that the presence of Zn in this site protects the protein from proteolysis and prevents the formation
of disulfide bridges within it. Finally, we show with the fully Zn-loaded reductase that thioredoxin or small thiols are dispensable
for the formation of the glycyl radical. However, they are necessary for obtaining high turnover numbers, suggesting that
they intervene in radical transfer steps subsequent to the formation of the glycyl radical. 相似文献