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1.
J Nanosci Nanotechnol ; 21(4): 2312-2322, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33500047

RESUMO

Looking for multifunctional materials, an assessment of the performances both as fire retardant and generator of electrically conductive surfaces for a three component mixture of graphene oxide, phosphoric acid and melamine applied on wood chipboard was performed. A simple approach was used to investigate the intumescent char formation and quantify the loss mass during vertical burning tests, in which the prepared samples were exposed for a certain time interval to a flame generated by an ethanol lamp in ambient conditions. Moreover, mass loss evolution and structural changes that occur during the burning process were more comprehensive investigated by differential thermal and thermogravimetric (DTA/TGA) techniques. By comparing the performances between the wood chipboard samples without any coverage and those covered with one or multiple component mixture, an increase of protection against the fire action was noticed when the three component mixture was used. Also, an improvement of the electrical properties was observed, after flame exposure of the samples covered with multiple layers (i.e., two and three), when the three component mixture was used. Morphological and structural investigations by microscopy (optical and electronic-SEMEDX), X-ray diffraction (XRD) and spectral (Raman, FTIR) methods are described. An assessment of market potential is also discussed.

2.
Food Chem Toxicol ; 116(Pt B): 227-232, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29678722

RESUMO

The environmental estrogen, zearalenone (ZEA), is found in the food supply from Fusarium fungal contamination in grains and sometimes used as a growth promoter for beef cattle. Long-term exposure to ZEA and its metabolites may present health risk due to higher estrogenic activity. Serum ZEA metabolites were measured to determine the exposure and the association with food intake in 48 overweight/obese women (52 ±â€¯9 years). The free and conjugated ZEA indicated the highest detection rate of all the metabolites. Conjugated ZEA and total ZEA metabolites were lower (p = 0.02) in overweight/obese than normal weight women, and free metabolites were either the same or showed a trend to be higher. In addition, those with highest (280-480 g/d) compared those with lowest (<115 g/d) meat consumption had higher conjugated serum ZEA metabolite concentrations (p < 0.05). Intakes of other food groups (i.e., dairy, cereal, etc.) were not associated with ZEA metabolites. These findings indicate that ZEA and its metabolites are detectable in nearly all women and concentrations are associated with greater meat intake, and influenced by body mass index. Determining how the food supply influences human concentrations of ZEA metabolites is warranted, as well as determining vulnerable populations.


Assuntos
Índice de Massa Corporal , Ingestão de Energia , Estrogênios não Esteroides/sangue , Zearalenona/sangue , Adulto , Cromatografia Líquida , Dieta , Estrogênios não Esteroides/metabolismo , Feminino , Abastecimento de Alimentos , Humanos , Limite de Detecção , Produtos da Carne , Menopausa , Pessoa de Meia-Idade , Obesidade/metabolismo , Sobrepeso/metabolismo , Espectrometria de Massas em Tandem , Zearalenona/metabolismo
3.
Osteoporos Int ; 28(1): 377-388, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27535752

RESUMO

The effects of higher than recommended vitamin D doses on bone mineral density (BMD) and quality are not known. In this study, higher intakes, in postmenopausal women undergoing weight control over 1 year, had no effect on areal or volumetric BMD but prevented the deterioration in cortical bone geometry. INTRODUCTION: Studies examining how bone responds to a standard dose of vitamin D supplementation have been inconsistent. In addition, the effects of higher doses on BMD and quality are not known. Postmenopausal women undergoing weight control to improve health outcomes are particularly at risk for bone loss and might benefit from supplemental vitamin D intake above the recommended allowance. METHODS: This 1-year-long, randomized, double-blind controlled study addresses whether vitamin D supplementation, in healthy overweight/obese older women, affects BMD and bone structural parameters. In addition, bone turnover and serum total, free, and bioavailable 25-hydroxyvitamin D (25OHD) responses to one of three daily levels of vitamin D3 (600, 2000, 4000 IU) with 1.2 Ca g/day during weight control were examined. RESULTS: Fifty-eight women (age, 58 ± 6 years; body mass index, 30.2 ± 3.8 kg/m2, serum 25OHD, 27.3 ± 4.4 ng/mL) were randomized to treatment. After 1 year, serum 25OHD concentrations increased to 26.5 ± 4.4, 35.9 ± 4.5, and 41.5 ± 6.9 ng/mL, in groups 600, 2000, and 4000 IU, respectively, and differed between groups (p < 0.01). Weight change was similar between groups (-3.0 ± 4.1 %). Cortical (Ct) thickness of the tibia changed by -1.5 ± 5.1 %, +0.6 ± 3.2 %, and +2.0 ± 4.5 % in groups 600, 2000, and 4000 IU, respectively, and each group was significantly different from each other (p < 0.05). CONCLUSION: The decline in Ct thickness was prevented with higher vitamin D3 supplementation, but there were no other significant changes due to treatment over 1 year. Whether these findings translate to changes in biomechanical properties leading to reduced fracture risk should be addressed in future studies.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Colecalciferol/administração & dosagem , Obesidade/terapia , Osteoporose Pós-Menopausa/prevenção & controle , Idoso , Antropometria/métodos , Composição Corporal/fisiologia , Peso Corporal/fisiologia , Densidade Óssea/fisiologia , Conservadores da Densidade Óssea/farmacologia , Colecalciferol/farmacologia , Dieta Redutora/efeitos adversos , Suplementos Nutricionais , Relação Dose-Resposta a Droga , Método Duplo-Cego , Exercício Físico/fisiologia , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Osteoporose Pós-Menopausa/etiologia , Pós-Menopausa/fisiologia , Redução de Peso/fisiologia
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