Ultraviolet B Radiation
Mostrando 1-12 de 146 artigos, teses e dissertações.
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1. Vitamin D levels in actinic keratosis: a preliminary study
Abstract: Background: Recent studies that investigated the effect of vitamin D on skin cancer risk have exhibited inconsistent results. Objective: The aim of the study was to evaluate vitamin D status in patients with actinic keratosis. Methods: A cross-sectional study was conducted on 31 patients with actinic keratosis and 29 healthy controls. Serum vita
An. Bras. Dermatol.. Publicado em: 2018-08
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2. Photodegradation Mechanisms on Poly(ε-caprolactone) (PCL)
Photodegradation of PCL was performed exposing injected specimens to ultraviolet radiation (UV-B) up to 9 weeks. Photodegradated PCL specimens were tested by Differential Scanning Calorimetry (DSC), Infrared Spectroscopy (FTIR), mechanical properties, Optical Microscopy (MO) and Scanning Electron Microscopy (SEM).Upon exposure decrease in elongation at break
Mat. Res.. Publicado em: 16/07/2018
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3. UV-B radiation as an elicitor of secondary metabolite production in plants of the genus Alternanthera
ABSTRACT Ultraviolet B radiation has been described as a potential elicitor agent of the synthesis of secondary metabolites in plants. Thus, the present study aimed to investigate the production of betalains and total flavonoids, as well as the antioxidant activity, of Alternanthera sessilis, A. brasiliana, A. tenella and A. philoxeroides exposed to differen
Acta Bot. Bras.. Publicado em: 02/07/2018
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4. Tensile properties and color and mass variations of GFPR composites under alkaline and ultraviolet exposures
The objective of the present study was to evaluate the influence of two different environmental conditions on the quantitative change of color and mass, tensile strength and modulus of elasticity of glass fiber reinforced polymers (GFRP) produced in Brazil. For this purpose, specimens were taken from pultruded composite profiles with two different matrices (
Matéria (Rio J.). Publicado em: 2016-03
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5. Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America
Abstract The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-mel
An. Bras. Dermatol.. Publicado em: 2015-06
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6. Effects of UV-B radiation on Lecanicillium spp., biological control agents of the coffee leaf rust pathogen
Coffee leaf rust is the main disease of coffee and its causal agent is naturally hyperparasited by Lecanicillium lecanii, indicating its potential for biocontrol. Ultraviolet-B (UV-B) radiation is an important factor that interferes on application of biocontrol agents, and Lecanicillium can be affected by UV-B. The objective of this work was to evaluate the
Trop. plant pathol.. Publicado em: 2014-10
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7. Induction of neoplastic cells in rat skin
PURPOSE: To investigate the induction of neoplastic lesions under the action of ultraviolet B radiation (UVR-B) and dimethyl benzanthracene (DMBA).METHODS:Forty Wistar rats were assigned to four groups (ten animals each), according to the procedure: group A received UVR-B irradiation, group B received topic DMBA, group C, UVR-B+DMBA and group D as control, o
Acta Cir. Bras.. Publicado em: 2014-02
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8. Cutaneous changes in rats induced by chronic skin exposure to ultraviolet radiation and organophosphate pesticide
PURPOSE: To study the possible potentiation of the carcinogenic effects of ultraviolet radiation associated with an organophosphate pesticide. METHODS: Forty Wistar rats were assigned into four groups (n=10 each) randomized according to the procedures: group A received only UVR-B radiation; group B, UVR-B for eight weeks followed by a seven week period
Acta Cir. Bras.. Publicado em: 2014-01
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9. Efeitos da radiação ultravioleta solar em algas de importância econômica da região subantártica do Chile durante a primavera / Effects of ultraviolet solar radiation on economically important algae from Chilean Sub-Antartic region during spring
Este trabalho analisou os efeitos da radiação solar UV (UV-A e UV-B) em duas espécies de importância comercial do Chile, Mazzaella laminarioides e Porphyra columbina durante a primavera, período no qual freqüentemente tem sido verificado um aumento de radiação UV-B decorrente da diminuição da camada de ozônio. A interação entre a radiação UV e
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/12/2011
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10. Alterações nos cabelos não pigmentados causadas por radiação ultravioleta, visível e infravermelha / Changes in white hair caused by ultraviolet, visible and infrared radiation
O cabelo branco se torna amarelo com o tempo, apesar de não possuir melanina, o pigmento responsável pela coloração. Este amarelecimento gera insatisfação nas pessoas. Neste trabalho estudamos em profundidade as mudanças de cor e as propriedades mecânicas do cabelo branco após exposição ao UV, Vis e IV, e os fatores que afetam o amarelecimento, in
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/07/2011
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11. Avaliação da fototoxicidade do antraceno sobre a mortalidade e o dano ao DNA de juvenis de pampos, Trachinotus carolinus (Linnaeus, 1766) / Assessment of the effect of the phototoxicity of anthracene on the mortality and damage to the DNA of juveniles of Florida pompanos, Trachinotus carolus
Polycyclic aromatic hydrocarbons are toxic and/or genotoxic to a variety of marine organisms and under solar or artificial ultraviolet radiation acute toxicity of many of them can be substantially enhanced. The aim of the present study was to examine the effect of the phototoxicity of anthracene on the mortality and damage to the DNA, assessed by the comet a
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/03/2011
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12. Efeito da radiação ultravioleta B sobre a comunidade bacteriana epifítica de soja (Glycine max L. Merril) / Effect of ultraviolet B radiation on epiphytic bacterial community of soybean (Glycine max L. Merrill)
A interação entre bactérias e plantas resulta na ocorrência de vários processos biológicos no ambiente e pode ser regulada por diferentes variáveis. Alterações nos fatores bióticos e abióticos interferem diretamente nesta interação levando a modificações na composição das comunidades bacterianas associadas às plantas. Dentre estas, as bact�
Publicado em: 2011