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951.
The gene for hemochromatosis was identified in 1996 and two mutations were found. Homozygosity for one of these, C282Y, is associated with hemochromatosis in a high percentage of patients. Genetic analysis of patient DNA is, therefore, a very useful tool to aid and confirm diagnosis and to screen asymptomatic relatives of patients to identify those at risk of developing this common, easily treated disease. 相似文献
952.
R. Robson 《Inorganica chimica acta》1984,85(2):195-198
The acetate-bridged complex, LPd2(CH3CO2), in which L3? is a binucleating ligand containing a bridging thiophenoxide unit, reacts with the syn-phenyldiazotate ion to yield the syn-diazotate-bridged complex LPd2(syn-C6H5NNO) and with the anti-phenyldiazotate ion to yield LPd2 (anti-C6H5NNO). The anti-complex isomerises to syn in boiling benzene, in contrast to the isomerisation of the free diazotate ions which proceeds spontaneously in the opposite direction. A para-nitro substituent has a pronounced labilising effect upon the isomerisation and LPd2(CH3CO2) reacts with sodium anti-p-nitrophenyldiazotate at room temperature to yield the syn complex, LPd2(syn-p-NO2·C6H4·NNO). Nitrosourethane, C2H5OOC·NH·NO, reacts with LPd2(CH3CO2) to generate LPd2(C2H5OOC·NNO). 相似文献
953.
Inhibition of ubiquitination and stabilization of human ubiquitin E3 ligase PIRH2 by measles virus phosphoprotein 总被引:3,自引:0,他引:3
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Chen M Cortay JC Logan IR Sapountzi V Robson CN Gerlier D 《Journal of virology》2005,79(18):11824-11836
Using a C-terminal domain (PCT) of the measles virus (MV) phosphoprotein (P protein) as bait in a yeast two-hybrid screen, a cDNA identical to the recently described human p53-induced-RING-H2 (hPIRH2) cDNA was isolated. A glutathione S-transferase-hPIRH2 fusion protein expressed in bacteria was able to pull down P protein when mixed with an extract from P-expressing HeLa cells in vitro, and myc-tagged hPIRH2 could be reciprocally co-immunoprecipitated with MV P protein from human cells. Additionally, immunoprecipitation experiments demonstrated that hPIRH2-myc, MV P, and nucleocapsid (N) proteins form a ternary complex. The hPIRH2 binding site was mapped to the C-terminal X domain region of the P protein by using a yeast two-hybrid assay. The PCT binding site was mapped on hPIRH2 by using a novel yeast two-hybrid tagged PCR approach and by co-immunoprecipitation of hPIRH2 cysteine mutants and mouse/human PIRH2 chimeras. The hPIRH2 C terminus could mediate the interaction with MV P which was favored by the RING-H2 motif. When coexpressed with an enhanced green fluorescent protein-tagged hPIRH2 protein, MV P alone or in a complex with MV N was able to redistribute hPIRH2 to outside the nucleus, within intracellular aggregates. Finally, MV P efficiently stabilized hPIRH2-myc expression and prevented its ubiquitination in vivo but had no effect on the stability or ubiquitination of an alternative ubiquitin E3 ligase, Mdm2. Thus, MV P protein is the first protein from a pathogen that is able to specifically interact with and stabilize the ubiquitin E3 ligase hPIRH2 by preventing its ubiquitination. 相似文献
954.
955.
Fernandes L Fortes ZB Casarini DE Nigro D Tostes RC Santos RA de Carvalho MH 《Regulatory peptides》2005,127(1-3):183-189
The present study determined the participation of PGI2 in the angiotensin-(1-7) [Ang-(1-7)]/bradykinin (BK) interaction, in the presence and absence of Angiotensin Converting Enzyme (ACE) inhibition, trying to correlate it with tissue levels of both peptides. The isolated mesenteric arteriolar bed of Spontaneously Hypertensive Rats (SHR) was perfused with Krebs or Krebs plus enalaprilat (10 nM), and drugs were injected alone or in association. BK (10 ng)-induced relaxation was potentiated by Ang-(1-7) (2.2 microg) in the presence or absence of enalaprilat. Ang-(1-7) receptor blockade [A-779 (4.8 microg)] did not interfere with the BK effect in preparations perfused with normal Krebs, but reversed the increased BK relaxation observed after ACE inhibition. PGI2 release by mesenteric vessels was not altered by BK or Ang-(1-7) alone, but was increased when both peptides were injected in association, in the absence or in the presence of enalaprilat. ACE inhibition caused a 2-fold increase in the BK tissue levels, and a significant decrease in the Ang-(1-7) values. We conclude that endogenous Ang-(1-7) has an important contribution to the effect of ACE inhibitors participating in the enhancement of BK response. The mechanism of Ang-(1-7) potentiating effect probably involves an increased production of PGI2. Our results suggest that a different enzymatic pathway (non-related to ACE) is involved in the local Ang-(1-7) metabolism. 相似文献
956.
Coutinho-Silva R Stahl L Cheung KK de Campos NE de Oliveira Souza C Ojcius DM Burnstock G 《American journal of physiology. Gastrointestinal and liver physiology》2005,288(5):G1024-G1035
Extracellular nucleotides interact with purinergic receptors, which regulate ion transport in a variety of epithelia. With the use of two different human epithelial carcinoma cell lines (HCT8 and Caco-2), we have shown by RT-PCR that the cells express mRNA for P2X1, P2X3, P2X4, P2X5, P2X6, P2X7, P2Y1, P2Y2, P2Y4, P2Y6, P2Y11, and P2Y12 receptors. Protein expression for P2Y1 and P2Y2 receptors was also demonstrated immunohistochemically, and P2X receptor subtype protein was present in the following decreasing order: P2X4 > P2X7 > P2X1 > P2X3 > P2X6 > P2X5 > P2X2. The functional presence of P2X7, P2Y1, P2Y2, and P2Y4 receptors was shown based on the effect of extracellular nucleotides on apoptosis or cell proliferation, and measurement of nucleotide-dependent calcium fluxes using a fluorometric imaging plate reader in the presence of different selective agonists and antagonists. ATP, at high concentrations, induced apoptosis through ligation of P2X7 and P2Y1 receptors; conversely, ATP, at lower concentrations, and UTP stimulated proliferation, probably acting via P2Y2 receptors. We therefore propose that stimulation or dysfunction of purinergic receptors may contribute at least partially to modulation of epithelial carcinoma cell proliferation and apoptosis. 相似文献
957.
958.
The caspase 8 inhibitor c-FLIP(L) modulates T-cell receptor-induced proliferation but not activation-induced cell death of lymphocytes
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Lens SM Kataoka T Fortner KA Tinel A Ferrero I MacDonald RH Hahne M Beermann F Attinger A Orbea HA Budd RC Tschopp J 《Molecular and cellular biology》2002,22(15):5419-5433
The caspase 8 inhibitor c-FLIP(L) can act in vitro as a molecular switch between cell death and growth signals transmitted by the death receptor Fas (CD95). To elucidate its function in vivo, transgenic mice were generated that overexpress c-FLIP(L) in the T-cell compartment (c-FLIP(L) Tg mice). As anticipated, FasL-induced apoptosis was inhibited in T cells from the c-FLIP(L) Tg mice. In contrast, activation-induced cell death of T cells in c-FLIP(L) Tg mice was unaffected, suggesting that this deletion process can proceed in the absence of active caspase 8. Accordingly, c-FLIP(L) Tg mice differed from Fas-deficient mice by showing no accumulation of B220(+) CD4(-) CD8(-) T cells. However, stimulation of T lymphocytes with suboptimal doses of anti-CD3 or antigen revealed increased proliferative responses in T cells from c-FLIP(L) Tg mice. Thus, a major role of c-FLIP(L) in vivo is the modulation of T-cell proliferation by decreasing the T-cell receptor signaling threshold. 相似文献
959.
Transgenic plant cells lacking mitochondrial alternative oxidase have increased susceptibility to mitochondria-dependent and -independent pathways of programmed cell death 总被引:18,自引:0,他引:18
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The plant mitochondrial electron transport chain is branched such that electrons at ubiquinol can be diverted to oxygen via the alternative oxidase (AOX). This pathway does not contribute to ATP synthesis but can dampen the mitochondrial generation of reactive oxygen species. Here, we establish that transgenic tobacco (Nicotiana tabacum L. cv Petit Havana SR1) cells lacking AOX (AS8 cells) show increased susceptibility to three different death-inducing compounds (H(2)O(2), salicylic acid [SA], and the protein phosphatase inhibitor cantharidin) in comparison with wild-type cells. The timing and extent of AS8 cell death are very similar among the three treatments and, in each case, are accompanied by the accumulation of oligonucleosomal fragments of DNA, indicative of programmed cell death. Death induced by H(2)O(2) or SA occurs by a mitochondria-dependent pathway characterized by cytochrome c release from the mitochondrion. Conversely, death induced by cantharidin occurs by a pathway without any obvious mitochondrial involvement. The ability of AOX to attenuate these death pathways may relate to its ability to maintain mitochondrial function after insult with a death-inducing compound or may relate to its ability to prevent chronic oxidative stress within the mitochondrion. In support of the latter, long-term treatment of AS8 cells with an antioxidant compound increased the resistance of AS8 cells to SA- or cantharidin-induced death. The results indicate that plants maintain both mitochondria-dependent and -independent pathways of programmed cell death and that AOX may act as an important mitochondrial "survival protein" against such death. 相似文献
960.
Gill Furze Alun Roebuck Peter Bull Robert JP Lewin David R Thompson 《BMC cardiovascular disorders》2002,2(1):1-5