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991.
Piao S Kim S Kim JH Park JW Lee BL Ha NC 《The Journal of biological chemistry》2007,282(14):10783-10791
A family of serine proteases (SPs) mediates the proteolytic cascades of embryonic development and immune response in invertebrates. These proteases, called easter-type SPs, consist of clip and chymotrypsin-like SP domains. The SP domain of easter-type proteases differs from those of typical SPs in its primary structure. Herein, we report the first crystal structure of the SP domain of easter-type proteases, presented as that of prophenoloxidase activating factor (PPAF)-I in zymogen form. This structure reveals several important structural features including a bound calcium ion, an additional loop with a unique disulfide linkage, a canyon-like deep active site, and an exposed activation loop. We subsequently show the role of the bound calcium and the proteolytic susceptibility of the activation loop, which occurs in a clip domain-independent manner. Based on biochemical study in the presence of heparin, we suggest that PPAF-III, highly homologous to PPAF-I, contains a surface patch that is responsible for enhancing the catalytic activity through interaction with a nonsubstrate region of a target protein. These results provide insights into an activation mechanism of easter-type proteases in proteolytic cascades, in comparison with the well studied blood coagulation enzymes in mammals. 相似文献
992.
Rah SY Park KH Nam TS Kim SJ Kim H Im MJ Kim UH 《The Journal of biological chemistry》2007,282(8):5653-5660
Activation of CD38 in lymphokine-activated killer (LAK) cells involves interleukin-8 (IL8)-mediated protein kinase G (PKG) activation and results in an increase in the sustained intracellular Ca(2+) concentration ([Ca(2+)](i)), cADP-ribose, and LAK cell migration. However, direct phosphorylation or activation of CD38 by PKG has not been observed in vitro. In this study, we examined the molecular mechanism of PKG-mediated activation of CD38. Nonmuscle myosin heavy chain IIA (MHCIIA) was identified as a CD38-associated protein upon IL8 stimulation. The IL8-induced association of MHCIIA with CD38 was dependent on PKG-mediated phosphorylation of MHCIIA. Supporting these observations, IL8- or cell-permeable cGMP analog-induced formation of cADP-ribose, increase in [Ca(2+)](i), and migration of LAK cells were inhibited by treatment with the MHCIIA inhibitor blebbistatin. Binding studies using purified proteins revealed that the association of MHCIIA with CD38 occurred through Lck, a tyrosine kinase. Moreover, these three molecules co-immunoprecipitated upon IL8 stimulation of LAK cells. IL8 treatment of LAK cells resulted in internalization of CD38, which co-localized with MHCIIA and Lck, and blebbistatin blocked internalization of CD38. These findings demonstrate that the association of phospho-MHCIIA with Lck and CD38 is a critical step in the internalization and activation of CD38. 相似文献
993.
Lim Y Park H Jeon J Han I Kim J Jho EH Oh ES 《The Journal of biological chemistry》2007,282(14):10398-10404
Focal adhesion kinase (FAK) mediates signal transduction in response to multiple extracellular inputs via tyrosine phosphorylation at specific residues. Although several tyrosine phosphorylation events have been linked to FAK activation and downstream signal transduction, the function of FAK phosphorylation at Tyr(407) was previously unknown. Here, we show for the first time that phosphorylation of FAK Tyr(407) increases during serum starvation, contact inhibition, and cell cycle arrest, all conditions under which activating FAK Tyr(397) phosphorylation decreases. Transfection of NIH3T3 cells with a phosphorylation-mimicking FAK 407E mutant decreased autophosphorylation at Tyr(397) and inhibited both FAK kinase activity in vitro and FAK-mediated functions such as cell adhesion, spreading, proliferation, and migration. The opposite effects were observed in cells transfected with nonphosphorylatable mutant FAK 407F. Taken together, these data suggest the novel concept that FAK Tyr(407) phosphorylation negatively regulates the enzymatic and biological activities of FAK. 相似文献
994.
Ha KN Traaseth NJ Verardi R Zamoon J Cembran A Karim CB Thomas DD Veglia G 《The Journal of biological chemistry》2007,282(51):37205-37214
Cardiac contraction and relaxation are regulated by conformational transitions of protein complexes that are responsible for calcium trafficking through cell membranes. Central to the muscle relaxation phase is a dynamic membrane protein complex formed by Ca2+-ATPase (SERCA) and phospholamban (PLN), which in humans is responsible for approximately 70% of the calcium re-uptake in the sarcoplasmic reticulum. Dysfunction in this regulatory mechanism causes severe pathophysiologies. In this report, we used a combination of nuclear magnetic resonance, electron paramagnetic resonance, and coupled enzyme assays to investigate how single mutations at position 21 of PLN affects its structural dynamics and, in turn, its interaction with SERCA. We found that it is possible to control the activity of SERCA by tuning PLN structural dynamics. Both increased rigidity and mobility of the PLN backbone cause a reduction of SERCA inhibition, affecting calcium transport. Although the more rigid, loss-of-function (LOF) mutants have lower binding affinities for SERCA, the more dynamic LOF mutants have binding affinities similar to that of PLN. Here, we demonstrate that it is possible to harness this knowledge to design new LOF mutants with activity similar to S16E (a mutant already used in gene therapy) for possible application in recombinant gene therapy. As proof of concept, we show a new mutant of PLN, P21G, with improved LOF characteristics in vitro. 相似文献
995.
Human apolipoprotein D (ApoD) occurs in plasma associated with high density lipoprotein. Apart from the involvement in lipid metabolism, its binding activity for progesterone and arachidonic acid plays a role in cancer development and neurological diseases. The crystal structures of free ApoD and its complex with progesterone were determined at 1.8A resolution and reveal a lipocalin fold. The narrow, mainly uncharged pocket within the typical beta-barrel accommodates progesterone with its acetyl side chain oriented toward the bottom. The cavity adopts essentially the same shape in the absence of progesterone and allows complexation of arachidonic acid as another cognate ligand. Three of the four extended loops at the open end of the beta-barrel expose hydrophobic side chains, which is an unusual feature for lipocalins and probably effects association with the high density lipoprotein particle by mediating insertion into the lipid phase. This mechanism is in line with an unpaired Cys residue in the same surface region that can form a disulfide cross-link with apolipoprotein A-II. 相似文献
996.
Saijou E Itoh T Kim KW Iemura S Natsume T Miyajima A 《The Journal of biological chemistry》2007,282(44):32327-32337
Nucleocytoplasmic translocation constitutes a foundation for nuclear proteins to exert their proper functions and hence for various biological reactions to occur normally in eukaryotic cells. We reported previously that EZI/Zfp467, a 12 zinc finger motif-containing protein, localizes predominantly in the nucleus, yet the underlying mechanism still remains elusive. Here we constructed a series of mutant forms of EZI and examined their subcellular localization. The results delineated a non-canonical nuclear localization signal in the region covering the 9th to the 12th zinc fingers, which was necessary for nuclear accumulation of EZI as well as sufficient to confer nuclear localizing ability to a heterologous protein. We also found that the N-terminal domain of EZI is necessary for its nuclear export, the process of which was not sensitive to the CRM1 inhibitor leptomycin B. An interaction proteomics approach and the following co-immunoprecipitation experiments identified the nuclear import receptor importin-7 as a molecule that associated with EZI and, importantly, short interfering RNA-mediated knockdown of importin-7 expression completely abrogated nuclear accumulation of EZI. Taken together, these results identify EZI as a novel cargo protein for importin-7 and demonstrate a nucleocytoplasmic shuttling mechanism that is mediated by importin-7-dependent nuclear localization and CRM1-independent nuclear export. 相似文献
997.
Song YM Lee SD Chowdappa R Kim HY Jin SK Kim IS 《Animal : an international journal of animal bioscience》2007,1(2):301-307
The objective of the present study was to investigate the effects of fermented oyster mushroom (Pleurotus ostreats) by-production (FOMP) supplementation on the growth performance, blood parameters, carcass traits and meat quality in finishing Berkshire pigs. FOMP was made by mixing oyster mushroom by-production with rice bran and barley bran and this mixture was fermented for 60 days. The experimental diets were 0, 3, 5 and 7% of FOMP added to C, T1, T2 and T3 in the basis diet for 7 weeks. Average daily gain (kg/day) was higher in C and T1 than in T2 and T3 ( P < 0.05). Average daily feed intake (kg/day) and feed conversion increased by the addition of FOMP ( P < 0.05). Total cholesterol and high-density lipoprotein cholesterol were higher in T3 than other treatments ( P < 0.05). Carcass weight (kg) was higher in C and T1 than in T2 and T3 ( P < 0.05). Dressing (%) was higher in C than in T3 ( P < 0.05). Crude protein was lower in T3 than in other treatments ( P < 0.05). Crude fat was higher in T2 and T3 than in C ( P < 0.05). pH24 was higher in C than in other treatments ( P < 0.05). Cooking loss (%) was higher in T1 than T2 ( P < 0.05). Water-holding capacity (%) was higher in C than in T1 ( P < 0.05). In meat colour, CIE a* was lower by the addition of FOMP ( P < 0.05). CIE b* was higher in C than in other treatments ( P < 0.05). In backfat colour, CIE L* was lower in T3 than other treatments ( P < 0.05). CIE b* was lower by addition of FOMP ( P < 0.05). Palmitoleic and oleic acid were higher in T3 than in other treatments ( P < 0.05). Linoleic and arachidonic acids were higher in T2 than in other treatments ( P < 0.05). The results indicate that 3% of FOMP affected the growth performance, carcass traits, meat quality and fatty acid in contrast to addition of 5% of FOMP for Berkshire pigs during the finishing period. 相似文献
998.
Root explants excised from carnation plants maintained in vitro formed off-white, friable calluses after three weeks of culture
on Murashige and Skoog (MS) medium supplemented with 1 mg l−1 thidiazuron (TDZ) and 1 mg l−1 α-naphthalaneacetic acid (NAA). These calluses were subsequently transferred to MS basal medium where, after an additional
four weeks of culture, approximately 50% of the calluses formed somatic embryos. However, calluses formed on root explants
that had been cultured on MS medium supplemented with 2,4-dichlorophenoxyacetic acid did not produce somatic embryos upon
transfer to MS basal medium. Somatic embryos developed into plantlets and subsequently were grown to maturity. These results
indicate that root explants have a high competence for somatic embryogenesis in carnation.
J. Seo and S.W. Kim contributed equally to this work. 相似文献
999.
Wordsworth S Buchanan J Regan R Davison V Smith K Dyer S Campbell C Blair E Maher E Taylor J Knight SJ 《Genomic Medicine》2007,1(1-2):35-45
Array based comparative genomic hybridisation (aCGH) is a powerful technique for detecting clinically relevant genome imbalance
and can offer 40 to > 1000 times the resolution of karyotyping. Indeed, idiopathic learning disability (ILD) studies suggest
that a genome-wide aCGH approach makes 10–15% more diagnoses involving genome imbalance than karyotyping. Despite this, aCGH
has yet to be implemented as a routine NHS service. One significant obstacle is the perception that the technology is prohibitively
expensive for most standard NHS clinical cytogenetics laboratories. To address this, we investigated the cost-effectiveness
of aCGH versus standard cytogenetic analysis for diagnosing idiopathic learning disability (ILD) in the NHS. Cost data from
four participating genetics centres were collected and analysed. In a single test comparison, the average cost of aCGH was
£442 and the average cost of karyotyping was £117 with array costs contributing most to the cost difference. This difference
was not a key barrier when the context of follow up diagnostic tests was considered. Indeed, in a hypothetical cohort of 100 ILD
children, aCGH was found to cost less per diagnosis (£3,118) than a karyotyping and multi-telomere FISH approach (£4,957).
We conclude that testing for genomic imbalances in ILD using microarray technology is likely to be cost-effective because
long-term savings can be made regardless of a positive (diagnosis) or negative result. Earlier diagnoses save costs of additional
diagnostic tests. Negative results are cost-effective in minimising follow-up test choice. The use of aCGH in routine clinical
practice warrants serious consideration by healthcare providers.
Copyright statement The Corresponding Author has the right to grant on behalf of all authors and does grant on behalf of all authors, an exclusive
licence (or non exclusive for government employees) on a worldwide basis to the BMJ Publishing Group Ltd, and its Licensees
to permit this article (if accepted) to be published in BMJ editions and any other BMJPGL products and to exploit all subsidiary
rights, as set out in our licence (bmj.com/advice/copyright.shtml).
Authorship The authors included on this paper fulfil the criteria of authorship and no one who fulfils the criteria has been excluded
from authorship. The authors made a substantial contribution to the conception, design, analysis and interpretation of data.
They were involved in drafting the article or revising it critically for important intellectual content and approving the
version to be published.
Contributorship Sarah Wordsworth (Guarantor): Planning, conducting and reporting work, interpretation of data, drafting and revising article.
James Buchanan: Conducting and reporting work, interpretation of data, revising article.
Regina Regan: Completing costing questionnaire, providing protocol details, other costing information, interpretation of data,
information about learning disability and genome imbalance and revising article.
Val Davison: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting
article.
Kim Smith: Completing costing questionnaire, providing protocol details, drafting article.
Sara Dyer: Completing costing questionnaire and providing protocol details.
Carolyn Campbell: Completing costing questionnaire and providing protocol details.
Edward Blair: Critical appraisal of article for clinical content and revising article.
Eddy Maher: Completing costing questionnaire, providing protocol details, sharing overall laboratory experience and drafting
article.
Jenny Taylor: Planning and facilitating work between centres. Drafting and revising article.
Samantha JL Knight: Completing costing questionnaire, providing protocol details, other costing information, interpretation
of data, providing information about learning disability and genome imbalance, drafting and revising article.
Jenny Taylor and Samantha JL Knight contributed equally to the work presented. 相似文献
1000.
Kim ES Im JA Kim KC Park JH Suh SH Kang ES Kim SH Jekal Y Lee CW Yoon YJ Lee HC Jeon JY 《Obesity (Silver Spring, Md.)》2007,15(12):3023-3030
Objective: The objective of this study was to investigate the association among adiposity, insulin resistance, and inflammatory markers [high‐sensitivity C‐reactive protein (hs‐CRP), interleukin (IL)‐6, and tumor necrosis factor (TNF)‐α] and adiponectin and to study the effects of exercise training on adiposity, insulin resistance, and inflammatory markers among obese male Korean adolescents. Research Methods and Procedures: Twenty‐six obese and 14 lean age‐matched male adolescents were studied. We divided the obese subjects into two groups: obese exercise group (N = 14) and obese control group (N = 12). The obese exercise group underwent 6 weeks of jump rope exercise training (40 min/d, 5 d/wk). Adiposity, insulin resistance, lipid profile, hs‐CRP, IL‐6, TNF‐α, and adiponectin were measured before and after the completion of exercise training. Results: The current study demonstrated higher insulin resistance, total cholesterol, LDL‐C levels, triglyceride, and inflammatory markers and lower adiponectin and HDL‐C in obese Korean male adolescents. Six weeks of increased physical activity improved body composition, insulin sensitivity, and adiponectin levels in obese Korean male adolescents without changes in TNF‐α, IL‐6, and hs‐CRP. Discussion: Obese Korean male adolescents showed reduced adiponectin levels and increased inflammatory cytokines. Six weeks of jump rope exercise improved triglyceride and insulin sensitivity and increased adiponectin levels. 相似文献