Search results for "Figuration"
showing 10 items of 615 documents
Stereoselective Total Synthesis and Absolute Configuration of the Natural Decanolides (−)-Microcarpalide and (+)-Lethaloxin. Identity of (+)-Lethalox…
2005
[reaction: see text] Convergent, stereoselective syntheses of the pharmacologically active, naturally occurring lactones (-)-microcarpalide and (+)-lethaloxin have been achieved from the commercially available, chiral reagents (R)-glycidol, (S,S)-tartaric acid, and d-ribose as the starting materials. These syntheses have further served to establish the hitherto unknown absolute configuration of (+)-lethaloxin and to show its identity with (+)-pinolidoxin.
Life cycle energy and CO2 emissions analysis of food packaging: an insight into the methodology from an Italian perspective
2016
Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, where…
Thermal and optical switching of bistable iron compounds and possible applications
1993
Abstract Iron(II) coordination compounds with ligand field strengths close to the mean spin pairing energy may undergo thermal spin transition in the solid as well as in the liquid state. The thermodynamically stable state is high spin (HS) 5T2 (under Oh symmetry) with (t2)4 e2 electron configuration above the critical transition temperature Tc, and low spin (LS) 1A1 with (t2)6 electron configuration below Tc. The spin transition curve γHS(T) (molar fraction of HS molecules as function of temperature) can be abrupt or gradual, with or without hysteresis, or even with a plateau near Tc. Tc itself can vary over the whole temperature scale between the liquid helium region up to above room temp…
Protonation and methylation reactions of 2-pyridyl-palladium(II) and -platinum(II) complexes
1983
Abstract The reactions of strong acids HX and HClO4 with the 2-pyridyl complexes [PdX(μ-C5H4N-C2,N)(PPh3)]2 (X = Cl, Br), trans-[PdCl(C5H4N-C2)(PEt3)2] and [PdCl(C5H4N-C2)(dppe)] yield the N-protonated derivatives cis-[PdX2-(C5H5N-C2)(PPh3)], trans-[PdCl(C5H5N-C2)(PEt3)2]ClO4 and [PdCl-(C5H5N-C2)(dppe)]ClO4, respectively. The terminal 2-pyridyl group of trans-[PdCl(C5H4N-C2)(PEt3)2] and [PdCl(C5H4N-C2)(dppe)] also reacts with Me2SO4/NaClO4 to give trans-[PdClC5H4(l-Me)N-C2(PEt3)2]ClO4 and [PdClC5H4(l-Me)N-C2(dppe)]ClO4. Analogous N-protonation or N-methylation reactions occur with trans-[PtBr(C5H4N-C2)(L)2] (L = PEt3, PPh3). The complexes trans-[MX(C5H5N-C2)(PMe2Ph)2]ClO4 (M = Pd, X = Cl an…
Structure of a polysaccharide from the lipopolysaccharides of Vibrio vulnificus strains CECT 5198 and S3-I2-36, which is remarkably similar to the O-…
2009
High-molecular-mass polysaccharides were released by mild acid degradation of the lipopolysaccharides of two wild-type Vibrio vulnificus strain, a flagellated motile strain CECT 5198 and a non-flagellated non-motile strain S3-I2-36. Studies by sugar analysis and partial acid hydrolysis along with (1)H and (13)C NMR spectroscopies showed that the polysaccharides from both strains have the same trisaccharide repeating unit of the following structure: --4)-beta-d-GlcpNAc3NAcylAN-(1--4)-alpha-l-GalpNAmA-(1--3)-alpha-d-QuipNAc-(1--where QuiNAc stands for 2-acetamido-2,6-dideoxyglucose, GalNAmA for 2-acetimidoylamino-2-deoxygalacturonic acid, GlcNAc3NAcylAN for 2-acetamido-3-acylamino-2,3-dideoxy…
Terpioside B, a difucosyl GSL from the marine sponge Terpios sp. is a potent inhibitor of NO release.
2010
Terpioside B (2a), a unique glycolipid containing two fucose residues in the furanose form in its pentasaccharide chain, was isolated from the marine sponge Terpios sp. Its complete stereostructure was solved by interpretation of mass spectrometric and NMR data along with CD and GG-MS analyses of its degradation products. Terpioside B is a potent inhibitor against LPS-induced NO release, and is considerably more active than simpler glycosphingolipids such as terpioside A and monoglucosylceramide.
A few remarks on the Inedita Pseudo-Chrysostomic Homily De transfiguratione et eleemosyna (CPG 5009; BHGn 1996t)
2021
The article presents the preliminary results of the author’s study of the unedited homily De transfiguratione et eleemosyna (CPG 5009; BHGn 1996t), ascribed to John Chrysostom. The question of the manuscript tradition is first discussed. The article shows that Maurice Sachot is right when he indicates only the manuscript Romanus Angelicus gr. 125 (T.1.7) as a manuscript witness of this homily and that the other two witnesses indicated by Pinakes are erroneous. Then, the descriptions of the folios that preserve the homily are analysed in the light of a new examination of them. This re-examination shows that hitherto several sources that inspired the compiler have gone unnoticed. This is foll…
Stereochemistry of terpene derivatives. Part 3: Hydrolytic kinetic resolution as a convenient approach to chiral aminohydroxyiminocaranes with local …
2002
Abstract We have developed a stereoselective hydrolytic kinetic resolution process for diastereoisomeric mixtures of epoxyiminocarene intermediates in the presence of ( R , R )-(−)-(salen)Co(III)OAc catalyst, this was applied as the first step in the synthesis of novel chiral aminohydroxyiminocarane derivatives with local anaesthetic activity. The absolute configuration of the product was confirmed by X-ray crystallography.
Swarming : An Investigation Practice Supporting a Bottom-up Ecological Transition
2022
Dans cet article, nous rendons compte des pratiques d’essaimage d’initiatives locales de transition portées par des collectifs citoyens et associatifs en région Bourgogne Franche-Comté. L’essaimage, défini comme une façon d’enquêter pour agir, caractérise un « activisme environnemental du faire » qui se structure de manière réticulaire et translocale. Ces multiples initiatives qui font des gestes du quotidien un levier de transformation écologique s’activent avec ou sans les institutions territoriales. Celles-ci, indépendamment de l’écho qu’elles renvoient à ces expérimentations, sont interpellées dans leur manière de concevoir l’action publique sous contrainte écologique forte.
Experimental and numerical analysis on post welding formability of FSWed AZ31 magnesium alloy thin joints obtained using a "Pinless" tool configurati…
2012
The post welding formability of friction stir welded AZ31 magnesium alloy thin sheets (1.5 mm thick), obtained using a “pinless” tool configuration, was widely investigated by means of the hemispherical punch method at 350°C, with a constant crosshead speed of 0.1 mm/s. The results were compared with those obtained on the base material. It has shown that formability of the joints is lower than the one of the base material. The experimental work was supported by a numerical investigation based on FEM in order to highlight the material flow occurring during the welding process. Additionally, hemispherical punch tests were simulated starting from the calculated conditions, in terms of accumula…