974 resultados para exopolysaccharide beta-1,3-glucanases
Resumo:
Water-insoluble glucan was isolated from the baker’s yeast Saccharomyces cerevisiae. The yeast cells were treated with alkali and the residue then with acid. Chemical and NMR (1D and 2D) analyses showed that a linear (1→3)-β-glucan was purified that was not contaminated with other carbohydrates, proteins or phenolic compounds. The effects of the glucan on wound healing were assessed in human venous ulcers by histopathological analysis after 30 days of topical treatment. (1→3)-β-glucan enhanced ulcer healing and increased epithelial hyperplasia, as well as increased inflammatory cells, angiogenesis and fibroblast proliferation. In one patient who had an ulcer that would not heal for over 15 years, glucan treatment caused a 67.8% decrease in the area of the ulcer. This is the first study to investigate the effects of (1→3)-β-glucan on venous ulcer healing in humans; our findings suggest that this glucan is a potential natural biological response modifier in wound healing
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Forskning och både nationella och internationella undersökningar har visat att Sveriges nyanlända elever får dåliga resultat i matematik. Om detta fortsätter finns risken att en stor grupp människor utesluts från samhället. Därför behöver de arbetssätt som karaktäriserar undervisning som främjar nyanländas matematiska förmåga belysas. Denna studie syftar till att ge råd till läraren för att lyckas med detta. För att finna dessa råd har en systematisk litteraturstudie gjorts. Genom analys av texter har tre huvudområden formats. Undervisning som främjar nyanlända elevers matematiska lärande har karaktäriserats som språkfokuserat med ett innehåll av visuella och praktiska material utförda av en lärare som innehar en integrerande och ansvarstagande karaktär. Resultatet av denna studie visar att en lärare som ser sina elever som individer och ser positivt på deras bidrag i klassrummet lyckas i sitt arbete mot att alla elever ska utvecklas så långt de kan.
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Studier visar att svenska elevers resultat i matematik har försämrats och att en av de bakomliggande orsakerna till resultatnedgången är bristande begreppsförståelse. Samtidigt rapporteras det om att eleverna i undervisningen allt mer lämnas ensamma i sitt lärande i så kallat individuellt arbete. Tolkningen som kan göras är att det finns ett samband mellan elevers försämrade matematikkunskaper och undervisningen de möter i matematik. Syftet med denna studie är att få kunskap om hur matematikundervisningen kan utformas för att ge elever i årskurs 1-3 möjlighet att utveckla en god begreppsförståelse i matematik. Svaret söktes genom en systematisk litteraturstudie där litteratur och aktuell forskning söktes systematiskt. I studiens resultat exemplifieras en rad kommunikationsverktyg för läraren att använda direkt i undervisning, men också andra typer av verktyg, för att stödja och utveckla elevers förståelse för matematiska begrepp. Vidare synliggörs också fördelar med en lärare som möjliggör en undervisning där eleverna själva får kommunicera matematik och som agerar resurs för dem i deras övergång från det vardagliga till det matematiska språket. Kommunikation kan därför ses som ett viktigt verktyg i matematikundervisningen då det kommer till att utveckla elevers begreppsförståelse. Undervisningsmiljön behöver därför utformas till att passa en mer kommunikativ undervisning; en tillåtande miljö där eleverna tillåts och stöttas i att prata matematik.
Resumo:
Water-insoluble glucan was isolated from the baker’s yeast Saccharomyces cerevisiae. The yeast cells were treated with alkali and the residue then with acid. Chemical and NMR (1D and 2D) analyses showed that a linear (1→3)-β-glucan was purified that was not contaminated with other carbohydrates, proteins or phenolic compounds. The effects of the glucan on wound healing were assessed in human venous ulcers by histopathological analysis after 30 days of topical treatment. (1→3)-β-glucan enhanced ulcer healing and increased epithelial hyperplasia, as well as increased inflammatory cells, angiogenesis and fibroblast proliferation. In one patient who had an ulcer that would not heal for over 15 years, glucan treatment caused a 67.8% decrease in the area of the ulcer. This is the first study to investigate the effects of (1→3)-β-glucan on venous ulcer healing in humans; our findings suggest that this glucan is a potential natural biological response modifier in wound healing
Resumo:
To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria
Resumo:
Water-insoluble glucan was isolated from the baker’s yeast Saccharomyces cerevisiae. The yeast cells were treated with alkali and the residue then with acid. Chemical and NMR (1D and 2D) analyses showed that a linear (1→3)-β-glucan was purified that was not contaminated with other carbohydrates, proteins or phenolic compounds. The effects of the glucan on wound healing were assessed in human venous ulcers by histopathological analysis after 30 days of topical treatment. (1→3)-β-glucan enhanced ulcer healing and increased epithelial hyperplasia, as well as increased inflammatory cells, angiogenesis and fibroblast proliferation. In one patient who had an ulcer that would not heal for over 15 years, glucan treatment caused a 67.8% decrease in the area of the ulcer. This is the first study to investigate the effects of (1→3)-β-glucan on venous ulcer healing in humans; our findings suggest that this glucan is a potential natural biological response modifier in wound healing
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Partiendo de la potencia que ha de generar se pretende realizar el diseño de los distintos elementos de transmisión de un aerogenerador con el fin de garantizar un funcionamiento óptimo del mismo.
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No more published?
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Purpose: To synthesize a series of analogues of 1,3,4-oxadiazole and to evaluate their antibacterial activity. Methods: Ethyl piperidin-4-carboxylate (1) was mixed with 4-toluenesulfonyl chloride (2) in benignant conditions to yield ethyl 1-(4-toluenesulfonyl)piperidin-4-carboxylate (3) and then 1-(4- toluenesulfonyl)piperidin-4-carbohydrazide (4). Intermolecular cyclization of 4 into 2-mercapto-5-(1-(4- toluenesulfonyl) piperidin-4-yl)-1,3,4-oxadiazole (5) was obtained on reflux with CS2 in the presence of KOH. Molecule 5 was stirred with alkyl halides, 6a-i, in DMF in the presence of LiH to synthesize the final compounds, 7a-i. The structures of these molecules were elucidated by Fourier transform infra-red (FTIR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) and electron impact mass spectrometry (EI-MS). Antibacterial activity was evaluated against five bacterial strains, namely, Salmonella typhi, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis, with ciprofloxacin used as standard antibacterial agent. Results: Out of nine synthesized derivatives, compound 7a was the most active against three bacterial strains, S. typhi, E. coli and P. aeruginosa, with minimum inhibitory concentration (MIC) of 9.11 ± 0.40, 9.89 ± 0.45 and 9.14 ± 0.72 μM, respectively, compared with 7.45 ± 0.58, 7.16 ± 0.58 and 7.14 ± 0.18 μM, respectively, for the reference standard (ciprofloxacin). Similarly, compounds 7a - 7c showed relatively good antibacterial activity against B. subtilis strain while compound 7e - 7g revealed good results against S. typhi bacterial strain. Conclusion: The results indicate that S-substituted derivatives of the parent compound are more effective antibacterial agents than the parent compound, even with minor differences in substituents