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Juliana S Luz Celso RR Ramos Márcia CT Santos Patricia P Coltri Fernando L Palhano Debora Foguel Nilson IT Zanchin Carla C Oliveira 《BMC biochemistry》2010,11(1):22
Background
The archaeal exosome is formed by a hexameric RNase PH ring and three RNA binding subunits and has been shown to bind and degrade RNA in vitro. Despite extensive studies on the eukaryotic exosome and on the proteins interacting with this complex, little information is yet available on the identification and function of archaeal exosome regulatory factors. 相似文献4.
We have developed efficient electrocatalysts for methanol oxidation using new synthetic method facilitating deposition of Pt–Ru very thin nanoplatelets on carbon nanoparticles The method involves oxidation of carbon support, adsorption of Pb2+, its reduction and galvanic displacement of Pb0 by Pt and/or Ru. The Pt mass activity of this catalyst is about 10 times higher than that of the commercial Pt–Ru/C. The catalyst with the 1:1 Pt/Ru ratio displayed the highest methanol oxidation activity per surface Pt atom. Our results demonstrate the new synthetic method that yields the catalyst with potential for solving the problem of high Pt loading in direct methanol fuel cell anodes. 相似文献
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In-situ spectroscopy was used to detect adsorbed species formed during the oxidation of formaldehyde at polycrystalline Au, Pt, Rh and Ir electrodes in alkaline solution. At the gold electrode, the spectra showed the oxidation of the gem-diol form of formaldehyde and the formation of an adsorbed formate species. At platinum, rhodium and iridium, adsorbed CO was observed in the hydrogen adsorption region where the oxidation of formaldehyde is strongly inhibited on these metals. Alternative routes for producing the poison are discussed. 相似文献
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Renata Monteiro-Maia Maria B Ortigão-de-Sampaio Rosa T Pinho Luiz RR Castello-Branco 《Journal of immune based therapies and vaccines》2006,4(1):1-6
We hypothesize that the energy strategy of a cell is a key factor for determining how, or if, the immune system interacts
with that cell. Cells have a limited number of metabolic states, in part, depending on the type of fuels the cell consumes.
Cellular fuels include glucose (carbohydrates), lipids (fats), and proteins. We propose that the cell's ability to switch
to, and efficiently use, fat for fuel confers immune privilege. Additionally, because uncoupling proteins are involved in
the fat burning process and reportedly in protection from free radicals, we hypothesize that uncoupling proteins play an important
role in immune privilege. Thus, changes in metabolism (caused by oxidative stresses, fuel availability, age, hormones, radiation,
or drugs) will dictate and initiate changes in immune recognition and in the nature of the immune response. This has profound
implications for controlling the symptoms of autoimmune diseases, for preventing graft rejection, and for targeting tumor
cells for destruction. 相似文献
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Zhang J Lima FH Shao MH Sasaki K Wang JX Hanson J Adzic RR 《The journal of physical chemistry. B》2005,109(48):22701-22704
We synthesized a new class of O2 electrocatalysts with a high activity and very low noble metal content. They consist of Pt monolayers deposited on the surfaces of carbon-supported nonnoble metal-noble metal core-shell nanoparticles. These core-shell nanoparticles were formed by segregating the atoms of the noble metal on to the nanoparticles' surfaces at elevated temperatures. A Pt monolayer was deposited by galvanic displacement of a Cu monolayer deposited at underpotentials. The mass activity of all the three Pt monolayer electrocatalysts investigated, viz., Pt/Au/Ni, Pt/Pd/Co, and Pt/Pt/Co, is more than order of magnitude higher than that of a state-of-the-art commercial Pt/C electrocatalyst. Geometric effects in the Pt monolayer and the effects of PtOH coverage, revealed by electrochemical data, X-ray diffraction, and X-ray absorption spectroscopy data, appear to be the source of the enhanced catalytic activity. Our results demonstrated that high-activity electrocatalysts can be devised that contain only a fractional amount of Pt and a very small amount of another noble metal. 相似文献
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V.E. Kazarinov R.R. Adzic V.N. Andreev A.N. Zhuchkov 《Journal of Electroanalytical Chemistry》1989,270(1-2)
With the use of a complex system combining radiotracer (adsorption) and pulsed potentiodynamic measurements, the adsorption and electrooxidation of formic acid on platinum modified by thallium adatoms were investigated. New data on the mechanism of electrocatalysis by thallium adatoms of the electrooxidation process of formic acid were obtained. The inhibiting action of thallium adatoms on the formation and electrooxidation of strongly adsorbed products of formic acid was proved. 相似文献