Segmented block copolymers of poly(ethylene glycol) and poly(ethylene terephthalate)

A new series of segmented copolymers were synthesized from poly(ethylene terephthalate) (PET) oligomers and polyethylene glycol) (PEG) by a two-step solution polymerization reaction. PET oligomers were obtained by glycolysis depolymerization. Structural features were denned by infrared and nuclear magnetic resonance (NMR) spectroscopy. The copolymer composition was calculated via 1H NMR spectroscopy. The content of soft PEG segments was higher than that of hard PET segments. A single glass-transition temperature was detected for all the synthesized segmented copolymers. This observation was found to be independent of the initial PET-to-PEG molar ratio. The molar masses of the copolymers were determined by gel permeation chromatographv (GPC). ©2004 Wiley Periodicals, Inc

Selected heavy metals and selenium in the blood of black sea turtle (Chelonia mydas agasiizzi) from Sonora, Mexico

A new series of segmented copolymers were synthesized from poly(ethylene terephthalate) (PET) oligomers and polyethylene glycol) (PEG) by a two-step solution polymerization reaction. PET oligomers were obtained by glycolysis depolymerization. Structural features were denned by infrared and nuclear magnetic resonance (NMR) spectroscopy. The copolymer composition was calculated via 1H NMR spectroscopy. The content of soft PEG segments was higher than that of hard PET segments. A single glass-transition temperature was detected for all the synthesized segmented copolymers. This observation was found to be independent of the initial PET-to-PEG molar ratio. The molar masses of the copolymers were determined by gel permeation chromatographv (GPC). "2004 Wiley Periodicals, Inc.",,,,,,"10.1002/pola.20301",,,"http://hdl.handle.net/20.500.12104/44425","http://www.scopus.com/inward/record.url?eid=2-s2.0-4444338219&partnerID=40&md5=d2eb00aebe928925be80030b03260011",,,,,,"17",,"Journal of Polymer Science, Part A: Polymer Chemistry",,"444

Synthesis and characterization of hydroxyapatite nanoparticles and their application in protein adsorption

A series of poly (ether-ester) copolymers were synthesized from poly(2,6 dimethyl-1,4-phenylene oxide) (PPO) and polyethylene terephthalate) (PET). The synthesis was carried out by two-step solution polymerization process. PET oligomers were synthesized via glycolysis and subsequently used in the copolymerization reaction. FTIR spectroscopy analysis shows the coexistence of spectral contributions of PPO and PET on the spectra of their ether-ester copolymers. The composition of the poly (ether-ester)s was calculated via 1H NMR spectroscopy. A single glass transi tion temperature was detected for all synthesized poly(ether-ester)s. Tg behavior as a function of poly(ether-ester) composition is well represented by the Gordon-Taylor equation. The molar masses of the copolymers synthesized were calculated by viscosimetry. " 2005 Wiley Periodicals, Inc.",,,,,,"10.1002/app.22539",,,"http://hdl.handle.net/20.500.12104/44919","http://www.scopus.com/inward/record.url?eid=2-s2.0-33644558371&partnerID=40&md5=748702e5af8c63a467e304cf5c7fed20",,,,,,"5",,"Journal of Applied Polymer Science",,"212

Synthesis and characterization of a poly(ether-ester) copolymer from poly(2,6 dimethyl-1,4-phenylene oxide) and poly(ethylene terephthalate)

A series of poly (ether-ester) copolymers were synthesized from poly(2,6 dimethyl-1,4-phenylene oxide) (PPO) and polyethylene terephthalate) (PET). The synthesis was carried out by two-step solution polymerization process. PET oligomers were synthesized via glycolysis and subsequently used in the copolymerization reaction. FTIR spectroscopy analysis shows the coexistence of spectral contributions of PPO and PET on the spectra of their ether-ester copolymers. The composition of the poly (ether-ester)s was calculated via 1H NMR spectroscopy. A single glass transi tion temperature was detected for all synthesized poly(ether-ester)s. Tg behavior as a function of poly(ether-ester) composition is well represented by the Gordon-Taylor equation. The molar masses of the copolymers synthesized were calculated by viscosimetry. © 2005 Wiley Periodicals, Inc

Juvenile polyautoimmunity in a rheumatology setting

Overt polyautoimmunity (PolyA) corresponds to the presence of more than one well-defined autoimmune disease (AD) manifested clinically in a single patient. The current study aimed to describe the main characteristics of juvenile PolyA in a pediatric rheumatology setting and analyze the chronological aspects, index cases, familial autoimmunity, and clustering pattern. This was a cross-sectional and multicenter study in which 313 children with overt PolyA were included. Patients were systematically interviewed and their medical records reviewed using a questionnaire that sought information about demographic, clinical, immunological, and familial characteristics. A hierarchical cluster analysis was done to determine similarities between autoimmune diseases based on PolyA. PolyA occurred simultaneously in 138 (44%) patients. Multiple autoimmune syndrome was observed in 62 (19.8%) patients. There were 25 index diseases of which, systemic lupus erythematosus (SLE, n = 134, 42.8%), juvenile idiopathic arthritis (JIA, n = 40, 12.7%), Hashimoto's thyroiditis (HT, n = 24, 7.66%), immune thrombocytopenic purpura (ITP n = 20, 6.39%), antiphospholipid syndrome (APS, n = 15, 4.79%), and vitiligo (VIT, n = 15, 4.79%) were the most frequent and represented 79.23% of the total number of patients. Familial autoimmunity influenced PolyA. A high aggregation of autoimmunity was observed (? r = 3.5). Three main clusters were identified, of which SLE and APS were the most similar pair of diseases (based on the Jaccard index) followed by HT and JIA, which were related to ITP and Sjögren's syndrome. The third cluster was composed of localized scleroderma and VIT. Our findings may assist physicians to make an early diagnosis of this frequent condition. Pediatric patients with ADs should be systematically assessed for PolyA. © 201

Juvenile polyautoimmunity in a rheumatology setting

Overt polyautoimmunity (PolyA) corresponds to the presence of more than one well-defined autoimmune disease (AD) manifested clinically in a single patient. The current study aimed to describe the main characteristics of juvenile PolyA in a pediatric rheumatology setting and analyze the chronological aspects, index cases, familial autoimmunity, and clustering pattern. This was a cross-sectional and multicenter study in which 313 children with overt PolyA were included. Patients were systematically interviewed and their medical records reviewed using a questionnaire that sought information about demographic, clinical, immunological, and familial characteristics. A hierarchical cluster analysis was done to determine similarities between autoimmune diseases based on PolyA. PolyA occurred simultaneously in 138 (44%) patients. Multiple autoimmune syndrome was observed in 62 (19.8%) patients. There were 25 index diseases of which, systemic lupus erythematosus (SLE, n = 134, 42.8%), juvenile idiopathic arthritis (JIA, n = 40, 12.7%), Hashimoto's thyroiditis (HT, n = 24, 7.66%), immune thrombocytopenic purpura (ITP n = 20, 6.39%), antiphospholipid syndrome (APS, n = 15, 4.79%), and vitiligo (VIT, n = 15, 4.79%) were the most frequent and represented 79.23% of the total number of patients. Familial autoimmunity influenced PolyA. A high aggregation of autoimmunity was observed (? r = 3.5). Three main clusters were identified, of which SLE and APS were the most similar pair of diseases (based on the Jaccard index) followed by HT and JIA, which were related to ITP and Sjögren's syndrome. The third cluster was composed of localized scleroderma and VIT. Our findings may assist physicians to make an early diagnosis of this frequent condition. Pediatric patients with ADs should be systematically assessed for PolyA. © 201