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排序方式: 共有92条查询结果,搜索用时 31 毫秒
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Books and archives experience aging which is affected by a variety of factors, such as microorganism, humidity, light and components of paper [1]. Thus, the studies concerning impacts of those factors on paper aging are required. In this paper, an accelerated paper aging was carried out to investigate the effects of acid and metals such as alum, copper ( Ⅱ ) sulfate, copper ( Ⅱ ) chloride, and iron (Ⅲ) chloride on paper aging. It was found that both acid and metals had impacts on paper aging. In particular, paper aging was far more accelerated in case that acid and metals were present in paper at the same time. 相似文献
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J. Kim D. C. Han J. M. Kim S. Y. Lee S. J. Kim J. R. Woo J. W. Lee S.-K. Jung K. S. Yoon H. G. Cheon S. S. Kim S. H. Hong B.-M. Kwon 《Cellular and molecular life sciences : CMLS》2009,66(10):1766-1781
Indenone KR-62776 acts as an agonist of PPARγ without inducing obesity in animal models and cells. X-ray crystallography reveals
that the indenone occupies the binding pocket in a different manner than rosiglitazone. 2-Dimensional gel-electrophoresis
showed that the expression of 42 proteins was altered more than 2.0-fold between KR-62776- or rosiglitazone-treated adipocyte
cells and control cells. Rosiglitazone down-regulated the expression of ERK1/2 and suppressed the phosphorylation of ERK1/2
in these cells. However, the expression of ERK1/2 was up-regulated in KR-62776-treated cells. Phosphorylated ERK1/2, activated
by indenone, affects the localization of PPARγ, suggesting a mechanism for indenone-inhibition of adipogenesis in 3T3-L1 preadipocyte
cells. The preadipocyte cells are treated with ERK1/2 inhibitor PD98059, a large amount of the cells are converted to adipocyte
cells. These results support the conclusion that the localization of PPARγ is one of the key factors explaining the biological
responses of the ligands.
Received 04 March 2009; received after revision 13 March 2009; accepted 17 March 2009 相似文献
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利用Ce(Ⅳ)在2mol/LHCl 介质中氧化二苯硫腙褪色的慢反应,用萃取平衡控制反应时间和水相中二苯硫腙的浓度,建立了非催化动力学分析法测定Ce(Ⅳ)的新方法。反应速度的检测是在620nm下测定反应前后CCl_4相中二苯硫腙吸光度的变化。方法的检测限为5.0×10~(-7) gCe(Ⅳ)·ml~(-1) ,线性范围为0. 5-5μgCe(Ⅳ)·ml~(-1)。对干扰严重的金属离子 Ag~+、Au~(3+)、Cu~(2+)、Hg~(2+)等可在 pH4-6条件下,用二苯硫腙的四氯化碳溶液萃取除去。将方法用于测定合成水样中Ce(Ⅳ),结果满意。 相似文献
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Directed outgrowth of optic fibres regenerating in vitro 总被引:1,自引:0,他引:1
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Biogenically driven organic contribution to marine aerosol 总被引:1,自引:0,他引:1
O'Dowd CD Facchini MC Cavalli F Ceburnis D Mircea M Decesari S Fuzzi S Yoon YJ Putaud JP 《Nature》2004,431(7009):676-680
Marine aerosol contributes significantly to the global aerosol load and consequently has an important impact on both the Earth's albedo and climate. So far, much of the focus on marine aerosol has centred on the production of aerosol from sea-salt and non-sea-salt sulphates. Recent field experiments, however, have shown that known aerosol production processes for inorganic species cannot account for the entire aerosol mass that occurs in submicrometre sizes. Several experimental studies have pointed to the presence of significant concentrations of organic matter in marine aerosol. There is some information available about the composition of organic matter, but the contribution of organic matter to marine aerosol, as a function of aerosol size, as well as its characterization as hydrophilic or hydrophobic, has been lacking. Here we measure the physical and chemical characteristics of submicrometre marine aerosol over the North Atlantic Ocean during plankton blooms progressing from spring through to autumn. We find that during bloom periods, the organic fraction dominates and contributes 63% to the submicrometre aerosol mass (about 45% is water-insoluble and about 18% water-soluble). In winter, when biological activity is at its lowest, the organic fraction decreases to 15%. Our model simulations indicate that organic matter can enhance the cloud droplet concentration by 15% to more than 100% and is therefore an important component of the aerosol-cloud-climate feedback system involving marine biota. 相似文献
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Montgomery KT Lee E Miller A Lau S Shim C Decker J Chiu D Emerling S Sekhon M Kim R Lenz J Han J Ioshikhes I Renault B Marondel I Yoon SJ Song K Murty VV Scherer S Yonescu R Kirsch IR Ried T McPherson J Gibbs R Kucherlapati R 《Nature》2001,409(6822):945-946
Our sequence-tagged site-content map of chromosome 12 is now integrated with the whole-genome fingerprinting effort. It provides accurate and nearly complete bacterial clone coverage of chromosome 12. We propose that this integrated mapping protocol serves as a model for constructing physical maps for entire genomes. 相似文献
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Tool wear, chatter vibration, chip breaking and built-up edge are main phenomena to be monitored in modern manufacturing processes, which are considered as important factors to the quality of products.They are closely related to the cutting parameters, which are to be selected in manufacturing process.However, it is very difficult to measure directly the cutting quality based on on-line monitoring.In this study, the relationship between the cutting parameters and cutting quality is analyzed.A Radical Basis Function (RBF) neural network based on-line quality recognition scheme is also presented, which monitors the level of surface roughness.The experimental results reveal that the RBF neural network has a high prediction success rate. 相似文献