Search results for "Sulfone"
showing 10 items of 113 documents
New types of environmental POPs
1998
Recent knowledge on sources, biomagnification and ecotoxic potential of earlier less studied persistent organic pollutants (POP) is briefly reviewed. Chlorohydrocarbons discussed are techno‐chemicals polychloronaphthalenes (PCN), polychloroterphenyls (PCT), octachlorostyrene (OCS) and hexachlorobutadiene, pulp bleachery wastes chlorocymenes (CYMS), chlorocymenenes (CYMD), alkylpolychlorophenanthrenes (RPCPH), alkylprolychlorobibenzyls (RPCBB) and alkylpolychloronaphthalenes (RPCN), and fish contaminants polychlorofluorenes (PCFL) and fluorenones (PCFLO), alkyl polychlorofluorenes (RPCFL), polychlorodihydroanthracenes (PCDHA) and polychloroanthracenes (PCAN). Aromatic chloroethers discussed …
FTIR isothermal cure kinetics and morphology of dicyanate ester resin/polysulfone blends
2005
Abstract The isothermal cure of a dicyanate ester monomer by “in situ” Fourier transform infrared spectroscopy (FTIR) has been investigated. The degree of cyanate conversion and the kinetic parameters have been determined for cobalt catalyzed and uncatalyzed resin as well as for polysulfone (PSF) modified systems at different curing temperatures. The cyanate conversion increases with the increment of temperature and with the addition of a catalyst, but it does not vary with the addition of PSF. In all the systems studied, the rate of reaction showed a second-order dependence on the cyanate concentration in the kinetically controlled stage. Moreover, the addition of PSF generates a matrix wi…
Investigation of compatibility of a dicyanate ester monomer and polysulfone by size-exclusion chromatography and viscometry
2003
The influence of solvent on the compatibility behaviour of Arocy B10, a cyanate ester monomer, and polysulfone (PSF) was investigated by means of dilute solution viscometry and of the preferential solvation parameter at 25 °C. The ternary systems under study are: tetrahydrofuran/Arocy B10/polysulfone (PSF), N,N-dimethylformamide/Arocy B10/PSF and dichloromethane/Arocy B10/PSF. Values of the specific viscosity of PSF in a ‘binary solvent’ formed by Arocy B10 + solvent have been used to determine the compatibility of the polymer blend Arocy B10/PSF. An interaction parameter Δb that depends on concentration has been determined. The preferential solvation parameter was measured by size-exclusio…
Endothelin receptor expression in idiopathic pulmonary arterial hypertension: effect of bosentan and epoprostenol treatment.
2011
Endothelin receptor antagonists are used to treat idiopathic pulmonary arterial hypertension (IPAH), but human pulmonary arterial endothelin receptor expression is not well defined. We hypothesised that disease and treatment would modify normal receptor distribution in pulmonary resistance arteries of children. Using immunohistochemistry and semiquantitative analysis, we investigated endothelin receptor subtypes A and B (ET(A) and ET(B), respectively), and endothelial nitric oxide synthase (eNOS) expression in peripheral pulmonary arteries of tissue from untreated children with IPAH (n=7), following extended combined bosentan and epoprostenol therapy (n=5) and from normal subjects (n=5). Cl…
Relaxation induced by cGMP phosphodiesterase inhibitors sildenafil and zaprinast in human vessels
2000
Abstract Background . Sildenafil is currently used in the treatment of erectile dysfunction. However, assessment of direct effects of sildenafil on coronary arteries and on arteries used as coronary grafts is unknown. This study was designed to investigate the effects of sildenafil on contracted human coronary, internal mammary, and radial arteries obtained from multiorgan donors. The observations were extended to forearm veins. Zaprinast was included in this study for comparison. Methods . Segments of left coronary, internal mammary, and radial arteries, and forearm veins were obtained from 16 multiorgan donors. Vascular rings were suspended in organ bath chambers and isometric tension was…
Sulfonēta poli(ēter ēter ketona) membrānu ar dažādām sulfonēšanās pakāpēm termiskās īpašības
2017
Sulfonēta poli(ēter ēter ketona) membrānu ar dažādām sulfonēšanas pakāpēm termiskās īpašības. Freibergs A. V., zinātniskais vadītājs, asoc. prof. Vaivars G. Bakalaura darbs. 47 lappuses, 17 attēli, 9 tabulas, 31 literatūras avots, 2 pielikumi. Latviešu valodā Darbā ir veikta sulfonēta poli(ēter ēter ketona) un tā membrānu sintēze ar dažādām sulfonēšanās pakāpēm 40° temperatūrā, pētīta šo reakciju kinētika, noteiktas membrānu sulfonēšanās pakāpes, noskaidrots šo membrānu kristāliskums atkarībā no sulfonēšanās pakāpes ar rentgendifraktometru Brucker D8 Advance, noteiktas šo membrānu stiklošanās temperatūras ar diferenciāli skenējošo kalorimetru Mettler Toledo LLC, kā arī veikta membrānu termo…
Potentialgesteuerte SS-Bindungsspaltung und Fluoreszenzmarkierungsstudien am Beispiel des Rinderinsulins
1985
Die drei SS-Brucken im Insulin konnen galvanostatisch unter Bildung der SH-A-Kette und der SH-B-Kette (Produktgemisch I) aufgespalten werden. Potentiostatisch gelingt bei -1.3 V (vs. SCE) die selektive Offnung der zwei interchenaren Disulfidbrucken (Produktgemisch II). Die vier SH-Gruppen im Produktgemisch II werden mit dem Vinylsulfon 1 blockiert (Produktgemisch III). Im Produktgemisch III wird die intrachenare Disulfidbrucke in der teilblockierten A-Kette bei -1.8 V (vs. SCE) potentiostatisch reduktiv geoffnet und mit dem fluoreszierenden Arylvinylsulfon 2 geschutzt (Produktgemisch IV). Auch die SH-Gruppen in den Produktgemischen I und II werden durch die fluoreszierenden Vinylsulfone 2 u…
Gezielte und reversible Fluoreszenzmarkierung von SH-Lysozym mit Vinylsulfonen
1985
Am Beispiel von SH-Lysozym wird gezeigt, wie man SH-Gruppen reversibel mit den Vinylsulfonen 1–4 nach Gl. (a) selektiv blockieren und nach Gl. (b) selektiv deblockieren kann. Das wasserlosliche Vinylsulfon 2 macht das blockierte SH-Lysozym wasserloslich. Durch Einwirkung von NaOH-Losung wird nach Gl. (b) das wasserunlosliche SH-Lysozym regeneriert. Die fluoreszierenden Vinylsulfone 3 und 4 konnen als Fluoreszenzmarker nach verschiedenen Arbeitsweisen zum qualitativen Nachweis und zur quantitativen Bestimmung von SH-Gruppen herangezogen werden. Selective and Reversible Fluorescence Marking of SH-Lysozyme with Vinyl Sulfones The SH groups of SH-lysozyme as a model substance are selectively bl…
Phosphororganische Verbindungen, 113. Chemoselektive gesteuerte Fluoreszenzmarkierung von α-Chymotrypsin
1985
α-Chymotrypsin wird durch die fluoreszierenden Phosphonoylfluoride 1 und 3 inhibiert. Die fluoreszenzmarkierten α-Chymotrypsine 5 und 6 wurden gelelektrophoretisch aufgetrennt. Die Fluoreszenz von 1 und 3 sowie 5 und 6 ist komplementar losungsmittelabhangig. Mit 3 fluoreszenzmarkiertes α-Chymotrypsin ergibt bei der sauren Hydrolyse den fluoreszierenden Serinester 7. Durch reduktive Offnung der SS-Brucken im fluoreszenzmarkierten 6 wird bewiesen, das 1 mit einem Serin der C-Kette reagiert hat. Das gleiche Ergebnis erhalt man, wenn man in 6 die durch Reduktion freigesetzten SH-Gruppen zunachst mit Vinylsulfonen blockiert und dann auftrennt. Organophosphorus Compounds, 113. — Chemoselectively …
CCDC 288795: Experimental Crystal Structure Determination
2006
Related Article: M.E.Gonzalez-Nunez, J.Royo, R.Mello, M.Baguena, J.M.Ferrer, C.R.de Arellano, G.Asensio, G.K.S.Prakash|2005|J.Org.Chem.|70|7919|doi:10.1021/jo0509511