Topic
Phosphotungstic acid
About: Phosphotungstic acid is a research topic. Over the lifetime, 1925 publications have been published within this topic receiving 38059 citations. The topic is also known as: Phosphowolframic acid.
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TL;DR: Measurements of the parameters of the dense projections suggest that the configuration of the Presynaptic vesicular grid is not uniform along the presynaptic areas.
Abstract: Studies have been carried out on the synapses in the cerebral cortex of rat by using impregnation with ethanolic solution of phosphotungstic acid, contrast staining with ruthenium red and impregnation with bismuth iodide, with or without subsequent uranyl acetate and lead citrate staining. It has been established that dense projections are adequately visualized with methods demonstrating basic chemical groups (phosphotungstic acid and bismuth iodide), whereas the synaptic vesicles are stained by techniques demonstrating acid chemical groups (ruthenium red and uranyl acetate and lead citrate). On the basis of these observations a hypothesis is forwarded concerning the mechanisms of migration of synaptic vesicles towards the presynaptic membrane. Measurements of the parameters of the dense projections suggest that the configuration of the presynaptic vesicular grid is not uniform along the presynaptic areas.
9 citations
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TL;DR: In this article, a polypyrrole (PPy) coating and PPy composite coatings were successfully electrodeposited on mild steel in the electrolytes of oxalic acid in the absence and presence of dopants using cyclic voltammetry.
Abstract: Polypyrrole (PPy) coating and PPy composite coatings were successfully electrodeposited on mild steel in the electrolytes of oxalic acid in the absence and presence of dopants using cyclic voltammetry. Two types of doping ions were employed: phosphotungstate (PW12O403–) and benzalkonium chloride (BAC). Corrosion-resistant performances of the coatings in 0.1 M HCl showed that PPy composite coatings in the presence of phosphotungstic acid and BAC exhibit more effective protection for iron in comparison with PPy formed in 0.3 M oxalic acid, and corrosion resistance of PPy–BAC is better than PPy–PW12 even though PPy–PW12 shows nobler open-circuit potential for a longer period of time than PPy–BAC. Impedance measurements show that, after immersion of 12 h in 0.1 M HCl, the polarization resistances of PPy–PW12 and PPy–BAC coatings reach 1860 and 3110 Ω cm2, respectively, compared to 640 Ω cm2 of PPy deposited from 0.3 M oxalic acid.
9 citations
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TL;DR: The results clearly show that PTA and STA are not biochemically inert and probably have more than a single mitochondrial site of action.
9 citations
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TL;DR: In this article, the catalytic properties of PW/HZSM-5 in the regioselective nitration of naphthalene to dinitronaphthalenes were investigated.
Abstract: HZSM-5-supported phosphotungstic acid (PW) has been prepared and characterized. The results indicate that 5 wt% PW/HZSM-5 calcined at 773 K has the largest surface area and high dispersion of PW. It was confirmed that Keggin units are present inside the catalyst and that the proton of PW and the silanol of HZSM-5 interact via bridging structure. The catalytic properties of PW/HZSM-5 in the regioselective nitration of naphthalene to dinitronaphthalene were investigated. The best results, i.e. 48.5 % yield of 1,5-dinitronaphthalene, 49.2 % yield of 1,8-dinitronaphthalene, and the highest ratio of 1,5-dinitronaphthalene to 1,8-dinitronaphthalene, were obtained by use of 5 wt% PW/HZSM-5.
9 citations
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15 May 20179 citations