The intercellular lipid bilayers of the stratum corneum provide the permeability barrier of the skin. To perform an electron microscopical examination of the ultrastructure of these bilayers, ruthenium tetroxide fixation is required. In this study an optimal fixation protocol was developed and selected upon comparing seven different fixation procedures, using glutaraldehyde (GA) and the postfixatives ruthenium red, osmium tetroxide (OsO4) and ruthenium tetroxide (RuO4) in combination with potassium ferrocyanide (K4Fe(CN)6) and potassium ferricyanide (K3Fe(CN)6). Instead of fixing skin with either OsO4 or RuO4, these two fixatives were combined in one protocol. In addition, the use of RuRed was introduced and the influence of both K4Fe(CN)6 and K3Fe(CN)6 in combination with RuO4 were examined. Furthermore, we compared two dehydration solvents, methanol and acetone. The most satisfying results were obtained when the skin was prefixed in GA and postfixed in OsO4 and RuO4 with K3Fe(CN)6, i.e. with Fe in its highest oxidation state (Fe3+). No differences were observed between dehydration in methanol and acetone.
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http://dx.doi.org/10.1046/j.1365-2818.1997.2200779.x | DOI Listing |
Radiat Prot Dosimetry
November 2024
Department of Radioecology, Institute for Environmental Sciences, 1-7, Ienomae, Obuchi, Rokkasho, Kamikita, Aomori, 039-3212, Japan.
J Org Chem
April 2024
Centro de Investigaciones Químicas-IICBA, Universidad Autónoma del Estado de Morelos. Av. Universidad 1001, 62209 Cuernavaca, Morelos, Mexico.
Herein we report for the first time the diastereoselective synthesis of (2,3a,7a)- and (2,3a,7a)-octahydroindole-2-phosphonic acid (Oic -fused stereoisomers) from diethyl ()- and ()-phosphopyroglutamate derivative. The key steps of this procedure are the ruthenium tetroxide oxidation of enantiomerically pure diethyl ()- and ()-phosphoprolinate obtained through Katritzky's benzotriazole-oxazolidine methodology, a highly diastereoselective successive double 4,5-diallylation of diethyl ()- and ()-phosphopyroglutamate with allyl bromide and allyltrimethylsilane with a -addition mode, and a ring-closing metathesis with Grubbs' first-generation ruthenium catalyst.
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November 2022
Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS - Unité de Catalyse et Chimie du Solide, F-59000 Lille, France.
Ru is a radioactive isotope usually generated by the nuclear industry within power plant reactors. During a nuclear accident, Ru reacts with oxygen, leading to the production of highly volatile ruthenium tetroxide RuO. The combination of volatility and radioactivity makes RuO, one of the most radiotoxic species and justifies the development of a specific setup for its capture and immobilization.
View Article and Find Full Text PDFRadiat Prot Dosimetry
September 2022
Department of Radioecology, Institute for Environmental Sciences, Rokkasho, Japan.
Radioactive ruthenium may be accidentally released from spent nuclear fuel reprocessing plants to the surrounding environment. To obtain basic information regarding the effect of radioactive ruthenium on the environment, we investigated changes in the source form of stable ruthenium added to rainwater through X-ray absorption fine structure analysis. Ruthenium tetroxide (RuO4), ruthenium dioxide (RuO2), ruthenium nitrosyl nitrate (Ru(NO)(NO3)3) and ruthenium chloride (RuCl3) were employed as test sources.
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August 2022
Dipartimento di Scienze del Farmaco e della Salute, Università di Catania, Viale A. Doria 6, 95125 Catania, Italy.
The direct oxidation reaction of isoxazolidines plays an important role in organic chemistry, leading to the synthesis of biologically active compounds. In this paper, we report a computational mechanistic study of RuO-catalyzed oxidation of differently -substituted isoxazolidines -. Attention was focused on the endo/exo oxidation selectivity.
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