全文获取类型
收费全文 | 696篇 |
免费 | 38篇 |
专业分类
734篇 |
出版年
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 18篇 |
2015年 | 22篇 |
2014年 | 26篇 |
2013年 | 39篇 |
2012年 | 62篇 |
2011年 | 36篇 |
2010年 | 25篇 |
2009年 | 27篇 |
2008年 | 33篇 |
2007年 | 38篇 |
2006年 | 38篇 |
2005年 | 27篇 |
2004年 | 34篇 |
2003年 | 28篇 |
2002年 | 23篇 |
2001年 | 18篇 |
2000年 | 24篇 |
1999年 | 19篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 10篇 |
1992年 | 17篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 5篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1961年 | 1篇 |
排序方式: 共有734条查询结果,搜索用时 15 毫秒
91.
Mitofusins and Drp1 are key components in mitochondrial membrane fusion and division, but the molecular mechanism underlying the regulation of their activities remains to be clarified. Here, we identified human membrane-associated RING-CH (MARCH)-V as a novel transmembrane protein of the mitochondrial outer membrane. Immunoprecipitation studies demonstrated that MARCH-V interacts with mitofusin 2 (MFN2) and ubiquitinated forms of Drp1. Overexpression of MARCH-V promoted the formation of long tubular mitochondria in a manner that depends on MFN2 activity. By contrast, mutations in the RING finger caused fragmentation of mitochondria. We also show that MARCH-V promotes ubiquitination of Drp1. These results indicate that MARCH-V has a crucial role in the control of mitochondrial morphology by regulating MFN2 and Drp1 activities. 相似文献
92.
Aoki T Hirono I Kim MG Katagiri T Tokuda Y Toyohara H Yamamoto E 《Fish & shellfish immunology》2000,10(7):623-630
Up-regulated genes of leucocytes expressing immunoglobulin (Ig+ leucocytes) of hirame rhabdovirus (HRV)-infected Japanese flounder were identified by differential hybridisation, using subtracted and un-subtracted cDNA probes. Ig+ leucocytes were separated from apparently healthy and HRV-infected Japanese flounder by the magnetic beads antibody method using mouse anti-Japanese flounder Ig monoclonal antibody (mab). A cDNA library was constructed from HRV-infected Japanese flounder leucocytes, and was screened with subtracted cDNA probes enriched in genes up-regulated by HRV infection. Fifty cDNAs were isolated for further analysis. These included cDNAs coding for homologues of interferon-inducible 56K protein (IFI56), Stat3, CEF-10, RGS5, inducible poly(A) binding protein, prolylcarboxylpeptidase, basigin III (Ig superfamily), MUC-18 (Ig superfamily), proteasome-nexin 1 (SERPIN), herpes virus entry mediator (TNFR family), collagenase III, gelatinase-b, megakaryocyte stimulating factor, Rab8-interacting protein, IgM, IgD and 20 unknown cDNA clones. The majority of these identified genes are reported for the first time in fish. From leucocytes mRNA for homologues of IFI56, CEF-10, Stat3, SERPIN and inducible poly (A) binding protein expression was shown to increase following HRV infection. 相似文献
93.
Haito-Sugino S Ito M Ohi A Shiozaki Y Kangawa N Nishiyama T Aranami F Sasaki S Mori A Kido S Tatsumi S Segawa H Miyamoto K 《American journal of physiology. Cell physiology》2012,302(9):C1316-C1330
Mutations in the apically located Na(+)-dependent phosphate (NaPi) cotransporter, SLC34A3 (NaPi-IIc), are a cause of hereditary hypophosphatemic rickets with hypercalciuria (HHRH). We have characterized the impact of several HHRH mutations on the processing and stability of human NaPi-IIc. Mutations S138F, G196R, R468W, R564C, and c.228delC in human NaPi-IIc significantly decreased the levels of NaPi cotransport activities in Xenopus oocytes. In S138F and R564C mutant proteins, this reduction is a result of a decrease in the V(max) for P(i), but not the K(m). G196R, R468W, and c.228delC mutants were not localized to oocyte membranes. In opossum kidney (OK) cells, cell surface labeling, microscopic confocal imaging, and pulse-chase experiments showed that G196R and R468W mutations resulted in an absence of cell surface expression owing to endoplasmic reticulum (ER) retention. G196R and R468W mutants could be partially stabilized by low temperature. In blue native-polyacrylamide gel electrophoresis analysis, G196R and R468W mutants were either denatured or present in an aggregation complex. In contrast, S138F and R564C mutants were trafficked to the cell surface, but more rapidly degraded than WT protein. The c.228delC mutant did not affect endogenous NaPi uptake in OK cells. Thus, G196R and R468W mutations cause ER retention, while S138F and R564C mutations stimulate degradation of human NaPi-IIc in renal epithelial cells. Together, these data suggest that the NaPi-IIc mutants in HHRH show defective processing and stability. 相似文献
94.
95.
Yamaguchi F Umeda Y Shimamoto S Tsuchiya M Tokumitsu H Tokuda M Kobayashi R 《The Journal of biological chemistry》2012,287(17):13787-13798
PP5 is a unique member of serine/threonine phosphatases comprising a regulatory tetratricopeptide repeat (TPR) domain and functions in signaling pathways that control many cellular responses. We reported previously that Ca(2+)/S100 proteins directly associate with several TPR-containing proteins and lead to dissociate the interactions of TPR proteins with their client proteins. Here, we identified protein phosphatase 5 (PP5) as a novel target of S100 proteins. In vitro binding studies demonstrated that S100A1, S100A2, S100A6, and S100B proteins specifically interact with PP5-TPR and inhibited the PP5-Hsp90 interaction. In addition, the S100 proteins activate PP5 by using a synthetic phosphopeptide and a physiological protein substrate, Tau. Overexpression of S100A1 in COS-7 cells induced dephosphorylation of Tau. However, S100A1 and permanently active S100P inhibited the apoptosis signal-regulating kinase 1 (ASK1) and PP5 interaction, resulting the inhibition of dephosphorylation of phospho-ASK1 by PP5. The association of the S100 proteins with PP5 provides a Ca(2+)-dependent regulatory mechanism for the phosphorylation status of intracellular proteins through the regulation of PP5 enzymatic activity or PP5-client protein interaction. 相似文献
96.
Kasai T Tokuda T Taylor M Nakagawa M Allsop D 《Biochemical and biophysical research communications》2012,422(3):375-380
Soluble amyloid-β (Aβ) oligomers are thought to be a cause of neurodegeneration and memory loss in Alzheimer disease (AD). We recently reported a newly developed enzyme linked immunosorbent assay (ELISA) for high molecular weight (HMW) Aβ oligomers in which the same Aβ monoclonal antibody, BAN50, was used for both capture and detection in a single antibody sandwich ELISA (SAS-ELISA) system. Our previous data suggest that this assay will be useful for the early diagnosis of AD, but its practical application to large-scale or longitudinal studies has been limited because of lack of a reliable calibration standard. In order to develop such a standard, we have now constructed a novel peptide using the multiple antigenic peptide (MAP) technique, where multiple epitopes of BAN50 were linked, via a spacer, to a branching lysine core. We show that the standard curve constructed from a 16-mer MAP covered the physiological range of signals obtained in the BAN50 SAS-ELISA from samples of human CSF, serum, and plasma. Furthermore, this 16-mer MAP is available in large quantities and is stable against freeze-thawing. We estimate that the signal per 1 pM of this standard corresponds to 1.54-5.0 pM of HMW Aβ oligomers. This MAP approach could also be used to provide an effective calibration standard for other SAS-ELISAs. 相似文献
97.
Phosphoinositides (PI) play important regulatory roles in cell physiology. Localization and quantitation of PIs within the cell is necessary to understand their precise function. Currently, ectopic expression of green fluorescent protein (GFP)-fused PI-binding domains is used to visualize PIs localized to the cell membrane. However, ectopically expressed PI-binding domains may compete with endogenous binding proteins, thus altering the physiological functions of the PIs. Here, we establish a novel method for quantification and visualization of PIs in cells and tissue samples using PI-binding domains labeled with quantum dots (Qdot) as specific probes. This method allowed us to simultaneously quantify three distinct PIs, phosphatidylinositol 3,4,5-triphosphatase [PtdIns(3,4,5)P(3)), PtdIns(3,4)P(2), and PtdIns(4,5)P(2), in crude acidic lipids extracted from insulin-stimulated cells. In addition, the method allowed the PIs to be visualized within fixed cells and tissues. Sequential and spatial changes in PI production and distribution were detected in platelet-derived growth factor (PDGF)-stimulated NRK49F cells. We also observed accumulation of PtdIns(3,4)P(2) at the dorsal ruffle in PDGF-stimulated NIH3T3 cells. Finally, we found PtdIns(3,4,5)P(3) was enriched in lung cancer tissues, which also showed high levels of phosphorylated Akt. Our new method to quantify and visualize PIs is expected to provide further insight into the role of lipid signaling in a wide range of cellular events. 相似文献
98.
99.
Osamu Ichikawa Kazuhiko Okazaki Hiroyuki Nakahira Megumi Maruyama Ryu Nagata Kumiko Tokuda Tomoko Horisawa Kazuto Yamazaki 《Neurochemistry international》2012
Lurasidone is a novel antipsychotic agent with high affinity for dopamine D2, 5-hydroxyltryptamine 5-HT2A, and 5-HT7 receptors. Lurasidone has negligible affinity for histamine H1 and muscarinic M1 receptors, which are thought to contribute to side effects such as weight gain, sedation, and worsening of cognitive deficits. Our interests focus on why lurasidone has such high selectivity for only a part of these aminergic G-protein coupled receptors (GPCRs) and the different binding profile from ziprasidone, which has the same benzisothiazolylpiperazine moiety as lurasidone. In order to address these issues, we constructed structural models of lurasidone–GPCR complexes by homology modeling of receptors, exhaustive docking of ligand, and molecular dynamics simulation-based refinement of complexes. This computational study gave reliable structural models for D2, 5-HT2A, and 5-HT7, which had overall structural complementarities with a salt bridge anchor at the center of the lurasidone molecule, but not for H1 and M1 owing to steric hindrance between the norbornane-2,3-dicarboximide and/or cyclohexane part of lurasidone and both receptors. By comparison with the structural models of olanzapine–GPCRs and ziprasidone–GPCRs constructed using the same computational protocols, it was suggested that the bulkiness of the norbornane-2,3-dicarboximide part and the rigidity and the bulkiness of the cyclohexyl linker gave lurasidone high selectivity for the desired aminergic GPCRs. Finally, this structural insight was validated by a binding experiment of the novel benzisothiazolylpiperazine derivatives. This knowledge on the structural mechanism behind the receptor selectivity should help to design new antipsychotic agents with preferable binding profiles, and the established computational protocols realize virtual screening and structure-based drug design for other central nervous system drugs with desired selectivity for multiple targets. 相似文献
100.
Sabree ZL Huang CY Arakawa G Tokuda G Lo N Watanabe H Moran NA 《Applied and environmental microbiology》2012,78(1):204-210
Beneficial microbial associations with insects are common and are classified as either one or a few intracellular species that are vertically transmitted and reside intracellularly within specialized organs or as microbial assemblages in the gut. Cockroaches and termites maintain at least one if not both beneficial associations. Blattabacterium is a flavobacterial endosymbiont of nearly all cockroaches and the termite Mastotermes darwiniensis and can use nitrogenous wastes in essential amino acid and vitamin biosynthesis. Key changes during the evolutionary divergence of termites from cockroaches are loss of Blattabacterium, diet shift to wood, acquisition of a specialized hindgut microbiota, and establishment of advanced social behavior. Termite gut microbes collaborate to fix nitrogen, degrade lignocellulose, and produce nutrients, and the absence of Blattabacterium in nearly all termites suggests that its nutrient-provisioning role has been replaced by gut microbes. M. darwiniensis is a basal, extant termite that solely retains Blattabacterium, which would show evidence of relaxed selection if it is being supplanted by the gut microbiome. This termite-associated Blattabacterium genome is ~8% smaller than cockroach-associated Blattabacterium genomes and lacks genes underlying vitamin and essential amino acid biosynthesis. Furthermore, the M. darwiniensis gut microbiome membership is more consistent between individuals and includes specialized termite gut-associated bacteria, unlike the more variable membership of cockroach gut microbiomes. The M. darwiniensis Blattabacterium genome may reflect relaxed selection for some of its encoded functions, and the loss of this endosymbiont in all remaining termite genera may result from its replacement by a functionally complementary gut microbiota. 相似文献