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51.
Gonzalez-Juarrero M Shim TS Kipnis A Junqueira-Kipnis AP Orme IM 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(6):3128-3135
The influx of macrophages into the lungs is the major component of the granulomatous response to infection with Mycobacterium tuberculosis. In this investigation we used flow cytometric analysis to define macrophage populations entering the airways and lung tissues of infected mice. We demonstrate that by the judicious use of cell surface markers, especially CD11b and CD11c, several cell populations can be distinguished, allowing cell sorting and morphological definition. Primary populations of CD11b(-)/CD11c(+/high) were defined as alveolar macrophages, CD11b(high)/CD11c(+/high) as dendritic cells, and CD11b(+/mid)/CD11c(+/mid) as small macrophages or monocytes, and changes in the activation phenotype of these populations were followed over the early course of the infection. In further studies, these cell populations were compared with cells harvested during the chronic stage of the disease. During the chronic stage of infection, Ag-presenting class II molecules and activation markers were poorly expressed on dendritic, small macrophage, and monocyte cell populations, which may have important implications for the breakdown of the lesions during reactivation disease. This analytical approach may facilitate the further characterization of macrophage populations entering into the lung tissues and their relative contributions to host resistance to tuberculosis infection. 相似文献
52.
Viability of poliovirus/rhinovirus VPg chimeric viruses and identification of an amino acid residue in the VPg gene critical for viral RNA replication 下载免费PDF全文
Cheney IW Naim S Shim JH Reinhardt M Pai B Wu JZ Hong Z Zhong W 《Journal of virology》2003,77(13):7434-7443
Picornaviral RNA replication utilizes a small virus-encoded protein, termed 3B or VPg, as a primer to initiate RNA synthesis. This priming step requires uridylylation of the VPg peptide by the viral polymerase protein 3D(pol), in conjunction with other viral or host cofactors. In this study, we compared the viral specificity in 3D(pol)-catalyzed uridylylation reactions between poliovirus (PV) and human rhinovirus 16 (HRV16). It was found that HRV16 3D(pol) was able to uridylylate PV VPg as efficiently as its own VPg, but PV 3D(pol) could not uridylylate HRV16 VPg. Two chimeric viruses, PV containing HRV16 VPg (PV/R16-VPg) and HRV16 containing PV VPg (R16/PV-VPg), were constructed and tested for replication capability in H1-HeLa cells. Interestingly, only PV/R16-VPg chimeric RNA produced infectious virus particles upon transfection. No viral RNA replication or cytopathic effect was observed in cells transfected with R16/PV-VPg chimeric RNA, despite the ability of HRV16 3D(pol) to uridylylate PV VPg in vitro. Sequencing analysis of virion RNA isolated from the virus particles generated by PV/R16-VPg chimeric RNA identified a single residue mutation in the VPg peptide (Glu(6) to Val). Reverse genetics confirmed that this mutation was highly compensatory in enhancing replication of the chimeric viral RNA. PV/R16-VPg RNA carrying this mutation replicated with similar kinetics and magnitude to wild-type PV RNA. This cell culture-induced mutation in HRV16 VPg moderately increased its uridylylation by PV 3D(pol) in vitro, suggesting that it might be involved in other function(s) in addition to the direct uridylylation reaction. This study demonstrated the use of chimeric viruses to characterize viral specificity and compatibility in vivo between PV and HRV16 and to identify critical amino acid residue(s) for viral RNA replication. 相似文献
53.
Chang TS Kim MJ Ryoo K Park J Eom SJ Shim J Nakayama KI Nakayama K Tomita M Takahashi K Lee MJ Choi EJ 《The Journal of biological chemistry》2003,278(48):48092-48098
p57KIP2, a member of the Cip/Kip family of enzymes that inhibit several cyclin-dependent kinases, plays a role in many biological events including cell proliferation, differentiation, apoptosis, tumorigenesis and developmental changes. The human p57KIP2 gene is located in chromosome 11p15.5, a region implicated in sporadic cancers and Beckwith-Wiedemann syndrome. We here report that p57KIP2 physically interacts with and inhibits c-Jun NH2-terminal kinase/stress-activated protein kinase (JNK/SAPK). The carboxyl-terminal QT domain of p57KIP2 is crucial for the inhibition of JNK/SAPK. Overexpressed p57KIP2 also suppressed UV- and MEKK1-induced apoptotic cell death. p57KIP2 expression during C2C12 myoblast differentiation resulted in repression of the JNK activity stimulated by UV light. Furthermore, UV-stimulated JNK1 activity was higher in mouse embryonic fibroblasts derived from p57-/- mice than in the cells from wild-type mice. Taken together, these findings suggest that p57KIP2 modulates stress-activated signaling by functioning as an endogenous inhibitor of JNK/SAPK. 相似文献
54.
55.
Green fluorescent protein-labeled recombinant fluobody for detecting the picloram herbicide 总被引:1,自引:0,他引:1
Kim IS Shim JH Suh YT Yau KY Hall JC Trevors JT Lee H 《Bioscience, biotechnology, and biochemistry》2002,66(5):1148-1151
A green fluorescent protein-labeled fluobody was designed to develop a simple immunoassay method for detecting picloram herbicide in an environmental sample. The gfp gene was successfully inserted into the pSJF2 vector harboring the picloram-specific antibody fragment to yield pSJF2GFP. Picloram spiking in an environmental river sample could be indirectly detected by observing the fluorescence intensity value of the gfp-fluobody, exhibiting specific sensitivity to free picloram with an IC50 value of 50 ppb. Using the gfp-fluobody immunoassay avoids the enzyme-substrate reaction for calorimetric detection that is required in an enzyme-linked immunosorbent assay (ELISA). 相似文献
56.
Hydrazinocurcumin,a novel synthetic curcumin derivative,is a potent inhibitor of endothelial cell proliferation 总被引:2,自引:0,他引:2
Shim JS Kim DH Jung HJ Kim JH Lim D Lee SK Kim KW Ahn JW Yoo JS Rho JR Shin J Kwon HJ 《Bioorganic & medicinal chemistry》2002,10(8):2439-2444
Curcumin and some of its derivatives were known as in vivo inhibitors of angiogenesis. In present study, a novel curcumin derivative, named hydrazinocurcumin (HC) was synthesized and examined for its biological activities. HC potently inhibited the proliferation of bovine aortic endothelial cells (BAECs) at a nanomolar concentration (IC(50)=520 nM) without cytotoxicity. In vivo and in vitro angiogenesis experiments showed HC as a new candidate for anti-angiogenic agent. 相似文献
57.
Regulated mRNA turnover is a highly important process in control of gene expression. The specific sequence elements in mRNA modulate the stability of different mRNAs, which varies considerably in response to extracellular stimuli. But the mechanistic basis for regulation of mRNA turnover remains nebulous. Recent works indicate that several signaling pathways have been implicated in regulating the decay of specific mRNA and certain ARE binding proteins mediate rapid degradation of the mRNAs. This review provides a current knowledge of diverse extracellular signals contributing to stabilization of short-lived mRNA. 相似文献
58.
59.
Despite major improvements in tools and significant refinements of techniques, microsurgical anastomosis still carries a significant risk of failure due to microvascular thrombosis. The key to improving the success of microvascular surgery may lie in the pharmacologic control of thrombus formation. Central to pathologic arterial thrombosis are platelets. Glycoprotein IIb/IIIa is a highly abundant platelet surface receptor that plays a major role in platelet aggregation by binding platelets to each other through the coagulation factor fibrinogen. To explore the ability of antithrombotic agents to prevent microvascular thrombosis, a rabbit ear artery model was used in which a standardized arterial injury results in predictable thrombus formation. This model was used to examine whether SR121566A, a specific and potent glycoprotein IIb/IIIa inhibitor, can successfully prevent microsurgical thrombosis.Using a coded, double-blind experimental design, 20 rabbits (40 arteries) were assigned to four treatment groups: (1) saline injection (n = 10), (2) acetylsalicylic acid 10 mg/kg (n = 10), (3) heparin 0.5 mg/kg bolus with subsequent intermittent boluses of 0.25 mg/kg every 30 minutes (n = 10), and (4) SR121566A 2 mg/kg bolus (n = 10). After vessel damage and clamp release, arteries were assessed for patency at 5, 30, and 120 minutes by the Acland refill test. Coagulation assays, in vivo bleeding times, and ex vivo platelet aggregation studies were also conducted. Scanning electron microscopy was used to examine mural thrombus composition.A significant, fourfold increase in vessel patency following administration of SR121566A over saline control (80 percent versus 20 percent patency, respectively, at 35 minutes after reperfusion, p < 0.01) was noted. This was correlated with marked inhibition of ex vivo platelet aggregation. This antiplatelet treatment did not prolong coagulation assays (mean international normalized ratio: saline, 0.66 +/- 0.04; SR121566A, 0.64 +/- 0.03; mean thromboplastin time: saline, 19.63 +/- 0.67; SR121566A, 17.87 +/- 3.27) and bleeding times (mean bleeding time: saline, 42 +/- 4; SR121566A, 48 +/- 6). Scanning electron microscopy demonstrated extensive platelet and fibrin deposition in control vessel thrombi. In contrast, thrombi from SR121566A-treated vessels demonstrated predominance of fibrin with few platelets when examined under scanning electron microscopy.Administration of SR121566A was associated with a significant increase in vessel patency, without deleterious effects on coagulation assays or bleeding times. The increase in vessel patency was correlated with inhibition of platelet aggregation and decreased platelet deposition, as demonstrated by scanning electron microscopy. Glycoprotein IIb/IIIa antagonists represent a new class of anti-platelet agents that may be suited for inhibiting microsurgical thrombosis. This study supports further investigation into the use of these agents in microsurgery. 相似文献
60.
Inhibition of catalase activity by oxidative stress and its relationship to salicylic acid accumulation in plants 总被引:15,自引:0,他引:15
Ie-Sung Shim Yukie Momose Akihiro Yamamoto Dea-Wook Kim Kenji Usui 《Plant Growth Regulation》2003,39(3):285-292
The decrease in catalase activity and its relationship to change in salicylic acid content were investigated in rice, wheat, and cucumber seedlings exposed to oxidative stresses. A decrease in chlorophyll fluorescence (F/Fm), measured as an indicator of the oxidative stress, and a drop in catalase activity were observed following treatment with NaCl in all plant seedlings tested . Furthermore, such decreases in F/Fm and catalase activity were also observed under low temperature conditions in both rice cultivars, whereas the degrees of decrease were dependent on their low temperature tolerance . Although the content of salicylic acid increased in rice seedlings stressed by NaCl treatment, it was inversely correlated with the decrease in the catalase activity . Such a relationship between the decrease in catalase activity and increase in salicylic acid content was confirmed with paraquat treatment of the rice seedlings . These results suggested that the fall in catalase activity is a phenomenon occurring in many plant species under oxidative stress and is related to the accumulation of salicylic acid in oxidatively-stressed plants. 相似文献