Search results for "Bisphenol"
showing 10 items of 84 documents
Bisphenol A, genistein and vinclozolin: three endocrine disruptors which differentially affect the mammary gland in rats : critical window of exposure
2012
Bisphenol A, genistein and vinclozolin: three endocrine disruptors which differentially affect the mammary gland in rats : critical window of exposure. Colloque PNR-PE
Inverse gas chromatography study of acid-base properties of cation resin used as catalysts of Bisphenol A synthesis
2001
The inverse gas chromatography method have been used for estimation of relative number of acid and base active centres for two type cation exchangers that are used as catalysts of Bisphenol A industrial synthesis. It was stated that after a few weeks of the continuous work of reactors filled with the catalysts, the acid-base properties of the latter have undergone significant changes. The number of acid centres decreased while the number of base centres increased. Simultaneously, the decreased of the yield of the synthesis product was observed.
Abnormal peripubertal development of the rat mammary gland following exposure in utero and during lactation to a mixture of genistein and the food co…
2012
The impact of early exposure to endocrine disruptor mixtures on mammary gland development is poorly known. Here, we identify the effects of a conception to weaning exposure of rats to the phytoestrogen genistein (G) and/or the antiandrogen vinclozolin (V) at 1 mg/kg-d, alone or in association. Using several approaches, we found that G- and GV-exposed rats displayed significantly greater epithelial branching and proliferation, wider terminal end buds than controls at PND35, as well as ductal hyperplasia and periductal fibrosis. Focal branching defects were present in V-exposed rats. An increased ER and AR expression was observed in G- and CV- as compared to V-exposed rats at PND35. Surprisin…
Metody wydzielania, zatężania i oznaczania związków fenolowych z próbek środowiskowych i żywności
2011
Application of Molecular Imprinted Polymers for Selective Solid Phase Extraction of Bisphenol A
2016
Abstract Selective molecularly imprinted polymers (MIPs) with bisphenol A as template were synthesized using the non-covalent imprinting approach. MIPs were prepared using thermally initiated polymerization with 1,1’-azobis(cyclohexanecarbonitryle) (ACHN) as initiator and ethylene glycol dimethacrylate (EDMA) as a cross-linking agent. The tested functional monomers included methacrylic acid, acrylamide, and 4-vinylpyridine. The selectivity of the BPA-MIP for the solid phase extraction of bisphenol A was tested in samples containing other related alkylphenols. The polymers prepared in acetonitrile using methacrylic acid or acrylamide as monomer showed the highest selectivity towards target a…
A Study of Polycarbonate-Liquid Crystal Polymer Blends
1992
BThe morphologican and mechanical properties of blends of bisphenol-A polycarbonate (PC) with a wholly aromatic liquid crystal copolyesteramide (Vectra-B) are discussed with reference to the conditions used for their preparation. The blends made by extrusion behave as mixtures of incompatible polymers. THe behaviour of the blends prepared in a batch mixer depends strongly on mixing time. A slight decrease in the mechanical properties accompanies the morphological changes associated with a progressive improvement in the compatibility of the two polymers
Linear Organic Carbonates
2003
The most common and successful method for producing organic carbonates, including polycarbonates, has been based for long time on the reaction between an alcohol or phenol and phosgene. The existing strict environmental regulations and the expanding market for organic carbonates do not assure that this technology can continue to have a leading role in this area, due to the inherent riskfulness of the processes. The market expansion of dimethyl carbonate (DMC), diphenyl carbonate (DPC), and bisphenol A polycarbonate (BPA-PC) is a reality, finding its driving force from the industrialization of alternative routes by EniChem (Italy) and UBE (Japan). This favorable situation can be foreseen for…
Bisfenola A saturošo zobārstniecības kompozītu genotoksicitāte
2019
Daži zobārstniecībā izmantojamie sveķu kompozīti satur monomērus ar BPA kā bāzes elementu, kas izraisa dzīvo šūnu genotoksicitāti un spēj izraisīt dzīvo šūnu nāvi. Šie monomēri spēj noārdīties cilvēka siekalās esošo esterāžu iedarbībā, tādējādi izdalot toksiskos noārdīšanās produktus mutes dobumā. Izdalītie monomēri pat var iekļūt asinsritē, izejot cauri zoba struktūrām uz pulpu. Šī pētījuma mērķis bija izpētīt zobārstniecības kompozīta materiālu ietekmi uz cilvēka asins šūnām, tieši uz limfocītiem, un novērtēt šūnu DNS bojājumu līmeni. Lai izpētītu šo jautājumu, 4 dažādi komerciāli pieejamie zobārstniecības kompozīta materiālu fragmenti tika izmērcēti izolētās cilvēka perifēro asiņu mononu…
Photoactive Yellow Protein Chromophore Photoisomerizes around a Single Bond if the Double Bond Is Locked
2020
Photoactivation in the Photoactive Yellow Protein, a bacterial blue light photoreceptor, proceeds via photo-isomerization of the double C=C bond in the covalently attached chromophore. Quantum chemistry calculations, however, have suggested that in addition to double bond photo-isomerization, the isolated chromophore and many of its analogues, can isomerize around a single C-C bond as well. Whereas double bond photo-isomerization has been observed with x-ray crystallography, experimental evidence for single bond photo-isomerization is currently lacking. Therefore, we have synthesized a chromophore analogue, in which the formal double bond is covalently locked in a cyclopentenone ring and ca…
Effect of bisphenol A on ameloblasts and tooth enamel mineralization
2011
Effect of bisphenol A on ameloblasts and tooth enamel mineralization. Journées de l’école doctorale