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51.
Moghadam Sogand Sasan Ghahramani Maryam Khoshaman Kazem Oryan Ahmad Moosavi-Movahedi Ali Akbar Kurganov Boris I. Yousefi Reza 《Biochemistry. Biokhimii?a》2022,87(2):91-105
Biochemistry (Moscow) - The study was aimed to evaluate the impact of peroxynitrite (PON, oxidative stress agent in diabetes), methylglyoxal (MGO, diabetes-associated reactive carbonyl compound),... 相似文献
52.
Meiru Si Lei Zhang Muhammad Tausif Chaudhry Wei Ding Yixiang Xu Can Chen Ali Akbar Xihui Shen Shuang-Jiang Liu 《Applied and environmental microbiology》2015,81(8):2781-2796
Oxidation of methionine leads to the formation of the S and R diastereomers of methionine sulfoxide (MetO), which can be reversed by the actions of two structurally unrelated classes of methionine sulfoxide reductase (Msr), MsrA and MsrB, respectively. Although MsrAs have long been demonstrated in numerous bacteria, their physiological and biochemical functions remain largely unknown in Actinomycetes. Here, we report that a Corynebacterium glutamicum methionine sulfoxide reductase A (CgMsrA) that belongs to the 3-Cys family of MsrAs plays important roles in oxidative stress resistance. Deletion of the msrA gene in C. glutamicum resulted in decrease of cell viability, increase of ROS production, and increase of protein carbonylation levels under various stress conditions. The physiological roles of CgMsrA in resistance to oxidative stresses were corroborated by its induced expression under various stresses, regulated directly by the stress-responsive extracytoplasmic-function (ECF) sigma factor SigH. Activity assays performed with various regeneration pathways showed that CgMsrA can reduce MetO via both the thioredoxin/thioredoxin reductase (Trx/TrxR) and mycoredoxin 1/mycothione reductase/mycothiol (Mrx1/Mtr/MSH) pathways. Site-directed mutagenesis confirmed that Cys56 is the peroxidatic cysteine that is oxidized to sulfenic acid, while Cys204 and Cys213 are the resolving Cys residues that form an intramolecular disulfide bond. Mrx1 reduces the sulfenic acid intermediate via the formation of an S-mycothiolated MsrA intermediate (MsrA-SSM) which is then recycled by mycoredoxin and the second molecule of mycothiol, similarly to the glutathione/glutaredoxin/glutathione reductase (GSH/Grx/GR) system. However, Trx reduces the Cys204-Cys213 disulfide bond in CgMsrA produced during MetO reduction via the formation of a transient intermolecular disulfide bond between Trx and CgMsrA. While both the Trx/TrxR and Mrx1/Mtr/MSH pathways are operative in reducing CgMsrA under stress conditions in vivo, the Trx/TrxR pathway alone is sufficient to reduce CgMsrA under normal conditions. Based on these results, a catalytic model for the reduction of CgMsrA by Mrx1 and Trx is proposed. 相似文献
53.
Effect of neohesperidin dihydrochalcone on the activity and stability of alpha‐amylase: a comparative study on bacterial,fungal, and mammalian enzymes
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Elaheh Kashani‐Amin Azadeh Ebrahim‐Habibi Bagher Larijani Ali Akbar Moosavi‐Movahedi 《Journal of molecular recognition : JMR》2015,28(10):605-613
Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha‐amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha‐amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha‐amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha‐amylase surface in domain B. This domain shows differences in various alpha‐amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
54.
55.
Senger S Csokmay J Akbar T Tanveer A Jones TI Sengupta P Lilly MA 《Development (Cambridge, England)》2011,138(10):2133-2142
The nuclear pore complex (NPC) mediates the transport of macromolecules between the nucleus and cytoplasm. Recent evidence indicates that structural nucleoporins, the building blocks of the NPC, have a variety of unanticipated cellular functions. Here, we report an unexpected tissue-specific requirement for the structural nucleoporin Seh1 during Drosophila oogenesis. Seh1 is a component of the Nup107-160 complex, the major structural subcomplex of the NPC. We demonstrate that Seh1 associates with the product of the missing oocyte (mio) gene. In Drosophila, mio regulates nuclear architecture and meiotic progression in early ovarian cysts. Like mio, seh1 has a crucial germline function during oogenesis. In both mio and seh1 mutant ovaries, a fraction of oocytes fail to maintain the meiotic cycle and develop as pseudo-nurse cells. Moreover, the accumulation of Mio protein is greatly diminished in the seh1 mutant background. Surprisingly, our characterization of a seh1 null allele indicates that, although required in the female germline, seh1 is dispensable for the development of somatic tissues. Our work represents the first examination of seh1 function within the context of a multicellular organism. In summary, our studies demonstrate that Mio is a novel interacting partner of the conserved nucleoporin Seh1 and add to the growing body of evidence that structural nucleoporins can have novel tissue-specific roles. 相似文献
56.
Stewart AK Chebib FT Akbar SW Salas MJ Sonik RA Shmukler BE Alper SL 《Biochimie et biologie cellulaire》2011,89(2):224-235
The AE1 mutation G701D, associated with recessive distal renal tubular acidosis (dRTA), produces only minimal erythroid phenotype, reflecting erythroid-specific expression of stimulatory AE1 subunit glycophorin A (GPA). GPA transgene expression could theoretically treat recessive dRTA in patients and in mice expressing cognate Ae1 mutation G719D. However, human (h) GPA and mouse (m) Gpa amino acid sequences are widely divergent, and mGpa function in vitro has not been investigated. We therefore studied in Xenopus oocytes the effects of coexpressed mGpa and hGPA on anion transport by erythroid (e) and kidney (k) isoforms of wild-type mAe1 (meAe1, mkAe1) and of mAe1 mutant G719D. Coexpression of hGPA or mGpa enhanced the function of meAe1 and mkAe1 and rescued the nonfunctional meAe1 and mkAe1 G719D mutants through increased surface expression. Progressive N-terminal truncation studies revealed a role for meAe1 amino acids 22-28 in GPA-responsiveness of meAe1 G719D. MouseN-cyto/humanTMD and humanN-cyto/mouseTMD kAE1 chimeras were active and GPA-responsive. In contrast, whereas chimera mkAe1N-cyto/hkAE1 G701DTMD was GPA-responsive, chimera hkAE1N-cyto/mkAe1 G719DTMD was GPA-insensitive. Moreover, whereas the isolated transmembrane domain (TMD) of hAE1 G701D was GPA-responsive, that of mAe1 G719D was GPA-insensitive. Thus, mGpa increases surface expression and activity of meAe1 and mkAe1. However, the G719D mutation renders certain mAe1 mutant constructs GPA-unresponsive and highlights a role for erythroid-specific meAe1 amino acids 22-28 in GPA-responsiveness. 相似文献
57.
Wu SC Yoon D Chin J van Kirk K Seethala R Golla R He B Harrity T Kunselman LK Morgan NN Ponticiello RP Taylor JR Zebo R Harper TW Li W Wang M Zhang L Sleczka BG Nayeem A Sheriff S Camac DM Morin PE Everlof JG Li YX Ferraro CA Kieltyka K Shou W Vath MB Zvyaga TA Gordon DA Robl JA 《Bioorganic & medicinal chemistry letters》2011,21(22):6693-6698
Derived from the HTS hit 1, a series of hydroxyisoquinolines was discovered as potent and selective 11β-HSD1 inhibitors with good cross species activity. Optimization of substituents at the 1 and 4 positions of the isoquinoline group in addition to the core modifications, with a special focus on enhancing metabolic stability and aqueous solubility, resulted in the identification of several compounds as potent advanced leads. 相似文献
58.
Homocysteine thiolactone (HCTL) is a cyclic thioester of homocysteine, showing high reactivity toward lysine residues of proteins.
In the present study the structural properties and aggregation propensity of bovine pancreatic insulin were studied in the
presences of increasing concentration of HCTL (0–500 μM), using different spectroscopic techniques. As shown in this study,
HCTL induces gross structural alterations and subsequently aggregation of insulin in a dose dependent manner. Also induction
of insulin aggregation by HCTL occurs in a sequential process, where native protein with alpha-helical abundant structure
gradually transforms into partially folded conformations with the significant amount of beta-sheet. Since C-terminal B-chain
of insulin plays a critical role in stability of this protein, the structural alteration/aggregation induced by HCTL can be
consequence of homocysteinylation of the only Lysine residue (Lys29) on its B-chain. This study may have important implications
regarding the effect of HCTL on structure of insulin particularly in the pathological states linked to hyperhomocysteinemia. 相似文献
59.
Struebig MJ Kingston T Petit EJ Le Comber SC Zubaid A Mohd-Adnan A Rossiter SJ 《Ecology letters》2011,14(6):582-590
The potential for parallel impacts of habitat change on multiple biodiversity levels has important conservation implications. We report on the first empirical test of the 'species-genetic diversity correlation' across co-distributed taxa with contrasting ecological traits in the context of habitat fragmentation. In a rainforest landscape undergoing conversion to oil palm, we show that depauperate species richness in fragments is mirrored by concomitant declines in population genetic diversity in the taxon predicted to be most susceptible to fragmentation. This association, not seen in the other species, relates to fragment area rather than isolation. While highlighting the over-simplification of extrapolating across taxa, we show that fragmentation presents a double jeopardy for some species. For these, conserving genetic diversity at levels of pristine forest could require sites 15-fold larger than those needed to safeguard species numbers. Importantly, however, each fragment contributes to regional species richness, with larger ones tending to contain more species. 相似文献
60.
Wills M Akbar A Beswick M Bosch JA Caruso C Colonna-Romano G Dutta A Franceschi C Fulop T Gkrania-Klotsas E Goronzy J Griffiths SJ Henson S Herndler-Brandstetter D Hill A Kern F Klenerman P Macallan D Macualay R Maier AB Mason G Melzer D Morgan M Moss P Nikolich-Zugich J Pachnio A Riddell N Roberts R Sansoni P Sauce D Sinclair J Solana R Strindhall J Trzonkowski P van Lier R Vescovini R Wang G Westendorp R Pawelec G 《Immunity & ageing : I & A》2011,8(1):10-8
The Second International Workshop on CMV & Immunosenescence was held in Cambridge, UK, 2-4th December, 2010. The presentations covered four separate sessions: cytomegalovirus and T cell phenotypes; T cell memory frequency, inflation and immunosenescence; cytomegalovirus in aging, mortality and disease states; and the immunobiology of cytomegalovirus-specific T cells and effects of the virus on vaccination. This commentary summarizes the major findings of these presentations and references subsequently published work from the presenter laboratory where appropriate and draws together major themes that were subsequently discussed along with new areas of interest that were highlighted by this discussion. 相似文献