984 resultados para Protection factor


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A reliable and fast sensor for in vitro evaluation of solar protection factors (SPFs) of cosmetic products, based on the photobleaching kinetics of a nanocrystalline TiO(2)/dye UV-dosimeter, has been devised. The accuracy, robustness and suitability of the new device was demonstrated by the excellent matching of the predicted and the in vivo results up to SPF 70, for four standard samples analyzed in blind. These results strongly suggest that our device can be useful for routine SPF evaluation in laboratories devoted to the development or production of cosmetic formulations, since the conventional in vitro methods tend to exhibit unacceptably high errors above SPF similar to 30 and the conventional in vivo methods tend to be expensive and exceedingly time consuming. (C) 2011 Elsevier B.V. All rights reserved.

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Textile Technology: The sun-blocking properties of a textile are enhanced when a dye, pigment, delustrant, or ultraviolet absorber finish is present that absorbs ultraviolet radiation and blocks its transmission through a fabric to the skin. For this reason, dyed fabrics provide better sun protection than bleached fabrics. Since naturally-colored cottons contain pigments that produce shades ranging from light green to tan and brown, it seemed reasonable to postulate that they would provide better sun protection than conventional bleached cotton, and that natural pigments might prove more durable to laundering and light exposure than dyes, but there is no published research on the ultraviolet transmission values for naturally-pigmented cottons. The purpose of this study was to determine the ultraviolet protection (UPF) values of naturally-pigmented cotton in three shades (green, tan, and brown), and the effect of light exposure and laundering on the sun-blocking properties of naturally-pigmented cotton. Naturally-pigmented cotton specimens were exposed to xenon light and accelerated laundering, ultraviolet transmission values measured, and UPF values calculated following light exposure and laundering. The naturally-pigmented cottons exhibited significantly higher UPF values than conventional cotton (bleached or unbleached). Although xenon light exposure and laundering caused some fading, the UPF values of naturally-pigmented cotton continue to be sufficiently high so that all three shades continue to provide good sun protection after the equivalent of 5 home launderings and 80 American Association of Textile Chemists and Colorists fading units (AFUs) of xenon light exposure.

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A new concept for in vitro visual evaluation of sun protection factor (SPF) of cosmetic formulations based on a supramolecular ultraviolet (UV) dosimeter was clearly demonstrated. The method closely parallels the method validated for in vivo evaluation and relies on the determination of the slightest perceptible bleaching of an iron-complex dye/nanocrystallinetitanium dioxide interface (UV dosimeter) in combination with an artificial skin substrate simulating the actual human skin in the presence and absence of a cosmetic formulation. The successful evaluation of SPF was ensured by the similarity of the erythema response of our dosimeter and human skin to UV light irradiation. A good linear correlation of in vitro and in vivo data up to SPF 40 confirmed the effectiveness of such a simple, cheap, and fast method. In short, here we unravel a convenient and accessible visual FPS evaluation method that can help improving the control on cosmetic products contributing to the reduction of skin cancer, one of the critical public health issues nowadays. (C) 2011 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101:726732, 2012

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Ultraviolet (UV) radiation potentially damages the skin, the immune system, and structures of the eye. A useful UV sun protection for the skin has been established. Since a remarkable body of evidence shows an association between UV radiation and damage to structures of the eye, eye protection is important, but a reliable and practical tool to assess and compare the UV-protective properties of lenses has been lacking. Among the general lay public, misconceptions on eye-sun protection have been identified. For example, sun protection is mainly ascribed to sunglasses, but less so to clear lenses. Skin malignancies in the periorbital region are frequent, but usual topical skin protection does not include the lids. Recent research utilized exact dosimetry and demonstrated relevant differences in UV burden to the eye and skin at a given ambient irradiation. Chronic UV effects on the cornea and lens are cumulative, so effective UV protection of the eyes is important for all age groups and should be used systematically. Protection of children's eyes is especially important, because UV transmittance is higher at a very young age, allowing higher levels of UV radiation to reach the crystalline lens and even the retina. Sunglasses as well as clear lenses (plano and prescription) effectively reduce transmittance of UV radiation. However, an important share of the UV burden to the eye is explained by back reflection of radiation from lenses to the eye. UV radiation incident from an angle of 135°-150° behind a lens wearer is reflected from the back side of lenses. The usual antireflective coatings considerably increase reflection of UV radiation. To provide reliable labeling of the protective potential of lenses, an eye-sun protection factor (E-SPF®) has been developed. It integrates UV transmission as well as UV reflectance of lenses. The E-SPF® compares well with established skin-sun protection factors and provides clear messages to eye health care providers and to lay consumers. © 2014 Behar-Cohen et al, This work is published by Dove Medical Press Ltd.

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Background: Sun exposure increases risk of skin cancer, especially melanoma, incidence of which continues to rise. Reported skin cancer knowledge and trends in sun care behaviours are documented in a UK region where there has been 20 years of sun-related health promotion campaigns. Methods: In 2000, 2004 and 2008, a 'care in the sun' module was included in the Northern Ireland (NI) Omnibus survey. Randomly selected subjects were asked to complete a sun-related questionnaire and proportions of respondents analysed by demographic and socio-economic factors, with differences tested using z-tests and the chi-squared test. Results: Around 3623 persons responded. Skin cancer knowledge was high (97). Sun avoidance decreased with time and was lowest among younger age groups and males. Sunscreen use was high (70), unchanged over 8 years, and more likely among younger age groups, females, those in paid employment, and those with tertiary level education. Use of sunscreen with minimum Sun Protection Factor (SPF) 15 (a campaign message) increased from 45 to 70 (P

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 Improving ultraviolet (UV) protection of textiles is essential to protect wearers against UV radiation induced risks. In addition to fabric parameters, yarn parameters are important factors affecting UV protection of textiles. This work is to examine the influence of yarn parameters on UV protection in order to set up a statistical model for predicting the UV protection of yarns. Wool yarns with different variables were used to test the ultraviolet protection factor (UPF) values for data analysis and the model verification. The model provides the optimized parameters for the UV protective fabric design. This work is helpful as a pre-cursor to the development of a more advanced optical model, which will look at understanding the penetration of UV light through fibres, yarns and fabrics.

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The incidence of skin cancer is increasing worldwide. Protecting the skin from the sun by wearing protective clothing, using a sunscreen with appropriate sun protection factor, wearing a hat, and avoiding the sun are recommended as primary preventive activities by cancer agencies. In this paper the recent data relating to skin cancer primary preventive behaviour in Australia and other countries is reviewed. Comparison of the studies in a table format summarizing the methods, objectives, participants, findings and implications may be obtained from the corresponding author. The sun protection knowledge, attitudes and behaviour patterns observed in Australia are similar in other countries, although Australian studies generally, report higher knowledge levels about skin cancer and higher levels of sun protection. The findings suggest that sunscreen is the most frequent method of sun protection used across all age groups, despite recommendations that it should be at? adjunct to other forms of protection. While young children's sun protective behaviour is largely influenced by their parents' behaviours, they are still tinder protected, and sun protective measures such as seeking shade, avoiding the sun and protective clothing need to be emphasized. Adolescents have the lowest skin protection rates of all age groups. Within the adult age range, women and people with sensitive skin were most likely to be using skin protection. However, women were also more likely than men to sunbath deliberately and to use sun-tanning booths. The relationship between skin protection knowledge and attitudes, attitudes towards tanning and skin protection behaviour needs further investigation. Further studies need to include detailed assessments of sunscreen use and application patterns, and future health promotion activities need to focus on sun protection by wearing clothing and seeking shade to avoid increases in the sunburn rates observed to date.

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While knowledge about standardization of skin protection against ultraviolet radiation (UVR) has progressed over the past few decades, there is no uniform and generally accepted standardized measurement for UV eye protection. The literature provides solid evidence that UV can induce considerable damage to structures of the eye. As well as damaging the eyelids and periorbital skin, chronic UV exposure may also affect the conjunctiva and lens. Clinically, this damage can manifest as skin cancer and premature skin ageing as well as the development of pterygia and premature cortical cataracts. Modern eye protection, used daily, offers the opportunity to prevent these adverse sequelae of lifelong UV exposure. A standardized, reliable and comprehensive label for consumers and professionals is currently lacking. In this review we (i) summarize the existing literature about UV radiation-induced damage to the eye and surrounding skin; (ii) review the recent technological advances in UV protection by means of lenses; (iii) review the definition of the Eye-Sun Protection Factor (E-SPF®), which describes the intrinsic UV protection properties of lenses and lens coating materials based on their capacity to absorb or reflect UV radiation; and (iv) propose a strategy for establishing the biological relevance of the E-SPF. © 2013 John Wiley & Sons A/S.

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Childhood sun exposure has been associated with increased risk of developing melanoma later in life. Sunscreen, children.s preferred method of sun protection, has been shown to reduce skin cancer risk. However, the effectiveness of sunscreen is largely dependent on user compliance, such as the thickness of application. To reach the sun protection factor (SPF) sunscreen must be applied at a thickness of 2mg/cm2. It has been demonstrated that adults tend to apply less than half of the recommended 2mg/cm2. This was the first study to measure the thickness at which children apply sunscreen. We recruited 87 primary school aged children (n=87, median age 8.7, 5-12 years) from seven state schools within one Brisbane education district (32% consent rate). The children were supplied with sunscreen in three dispenser types (pump, squeeze and roll-on) and were asked to use these for one week each. We measured the weight of the sunscreen before and after use, and calculated the children.s body surface area (based on height and weight) and area to which sunscreen was applied (based on children.s self-reported body coverage of application). Combined these measurements resulted in an average thickness of sunscreen application, which was our main outcome measure. We asked parents to complete a self-administered questionnaire which captured information about potential explanatory variables. Children applied sunscreen at a median thickness of 0.48mg/cm2, significantly less than the recommended 2mg/cm2 (p<0.001). When using the roll-on dispenser (median 0.22mg/cm2), children applied significantly less sunscreen thickness, compared to the pump (median 0.75mg.cm2, p<0.001), and squeeze (median 0.57mg/cm2, p<0.001) dispensers. School grade (1-7) was significantly associated with thickness of application (p=0.032), with children in the youngest grades applying the most. Other variables that were significantly associated with the outcome variable included: number of siblings (p=0.001), household annual income (p<0.001), and the number of lifetime sunburns the child had experienced (p=0.007). This work is the first to measure children.s sunscreen application thickness and demonstrates that regardless of their age or the type of dispenser that they use, children do not apply enough sunscreen to reach the advertised SPF. It is envisaged that this study will assist in the formulation of recommendations for future research, practice and policy aimed at improving childhood sun protection to reduce skin cancer incidence in the future.

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We thank Dr Shedden and Dr Pall for their insightful comments and the opportunity to clarify a number of points from our work.1 The “protection factor” (PF) expressed as the inverse of the transmittance of contact lens (CL) material (1/Tλ), where T is the percentage transmittance of ultraviolet radiation (UVR) in a given waveband (UVC, UVB or UVA) of the UV spectrum for contact lenses is the standard method for reporting PF values and as such there should not be any controversy. We have calculated the PF for each wavelength across the entire UV spectrum (UVC, UVB, UVA) as presented in figure 3 of our previous publication.1 In that article, we were simply stating the observation when transmission in the UVC spectra band is considered especially because appreciable amounts of potentially carcinogenic short UV wavelengths was shown to be present in sunlight in our region three decades ago2 and these short wavelength photons are reported to be more biologically damaging to ocular tissues.3 In addition, the depletion of the Ozone layer is still continuing. Nevertheless, we understand the concern of the authors that the results of the PF might be confusing to those who are not familiar with the science of UVR and as such we have made some revisions to the findings of the calculated PF...

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A novel protective covering with a layered and staggered structure was proposed to protect concrete against projectile impact. Experimental study was conducted to investigate the ballistic behaviour of the concrete targets against 12.7 mm armour-piercing incendiary projectile at velocities ranging from 537.7 to 596.5 m/s. The results showed that the concrete targets with protective covering exhibited superior integrity with no damage on the distal surface, whereas the concrete targets without protective covering were fractured with penetrating cracks throughout the thickness of the target. Moreover, the protected concrete targets displayed significantly reduced penetration depth compared with the concrete targets without protective covering. The protective covering with epoxy adhesive interlayers had a bigger protection factor than that with silicone sealant interlayers, but the former suffered more severe damage than the latter.

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A radiação ultravioleta (UV) induz diversos efeitos nocivos nos organismos e a quantidade desta radiação que atinge a biosfera é afetada pela concentração de ozônio, latitude, altitude, clima e reflexão especular. As respostas de briófitas em relação aos efeitos da radiação UV e a presença de compostos que absorvem esta radiação têm sido estudadas. Sanionia uncinata, Holomitriopsis laevifolia e Leucobryum laevifolium são espécies de musgos encontrados em locais expostos a alta incidência de radiação UV e com habitats distintos. Considerando que as respostas de musgos contra os efeitos da radiação UV e seus mecanismos de proteção ainda são pouco caracterizados, o objetivo deste estudo foi investigar o potencial fotoprotetor e possíveis riscos toxicológicos associados aos extratos dos musgos S. uncinata, proveniente da Antártica e H. laevifolia e L. laevifolium, proveniente do Amazonas. Seus extratos metanólico (EM), aquoso (EA), hidroalcoólico (EH) e etanólico (EE) foram estudados com a caracterização química por absorção ao UV e visível e pela cromatografia líquida de alta eficiência; quantificação do índice total de compostos fenólicos; determinação da capacidade captadora do radical 2,2-difenil-1-picril-hidrazila a fim de avaliar as atividades antioxidantes; avaliação do potencial de fotoproteção cutânea pela determinação do fator de proteção solar; avaliações do potencial mutagênico e citototóxico, através do ensaio de Salmonella/microssoma, utilizando as cepas TA97, TA98, TA100, TA102 e TA104; do potencial fotomutagênico através do ensaio de fotomutagenicidade, usando as cepas TA102 e TA104; e investigação dos efeitos genotóxicos e fotogenotóxicos, pelo ensaio de micronúcleo e fotomicronúcleo, respectivamente, usando diferentes linhagens celulares estabelecidas. Foram encontradas atividades fotoprotetoras e antioxidantes e observou-se que os extratos se apresentaram singulares devido a sua composição química. Os resultados fotoprotetores, além dos mutagênicos/fotomutagênicos, genotóxicos/fotogenotóxicos e suas respectivas avaliações citotóxicas também permitiram selecionar extratos e suas concentrações, como promissores candidatos em fotoproteção Assim, os EA e EH de H. laevifolia e L. laevifolium apresentam, no geral, os resultados mais significativos, tornando-se potenciais para avaliações refinadas em fotoproteção e na separação de componentes que possam levar a futuras aplicações como antioxidantes e protetores solares ou como adjuvantes.

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Die nachfolgend berichteten Ergebnisse basieren auf einem vignettenbasierten 2x2-Szenario-Experiment, in das die Situationsfaktoren Entdeckungswahrscheinlichkeit und Vorteilswert sowie die Personenfaktoren Organisationaler Zynismus, das Fünf-Faktoren-Modell der Persönlichkeit und Intelligenz einbezogen wurden. In diesem Bericht werden vorrangig die Ergebnisse zur Persönlichkeitsdimension Gewissenhaftigkeit vorgestellt, einem der Faktoren des Fünf-Faktoren-Modells der Persönlichkeit. Diese Ergebnisse werden ausführlich berichtet, weil sie von besonderer Bedeutung für das vom TÜV Hannover/Sachsen-Anhalt e.V. finanzierte Forschungsprojekt Korruption – Risikofaktoren der Person und der Situation (Laufzeit 2011 bis 2015) sind. Die nachfolgend berichtete Untersuchung zeigt, dass ein akteurszentrierter Ansatz in der Korruptionsursachenforschung grundsätzlich sinnvoll ist. Es wurden 113 Auszubildende in den Bereichen Banken- und Versicherungen sowie Sozialversicherung befragt. Die Ergebnisse zeigen, dass Korruption als verbreitete Verhaltensweise angesehen wird, die jedoch als verwerflich gilt. Während die einbezogenen Situationsfaktoren keine nennenswerten Effekte auf die Korruptionsbereitschaft hatten, führten einige der Personenfaktoren zu signifikanten Ergebnissen. Gewissenhaftigkeit kommt hierbei als Schutzfaktor vor korrupten Handlungen besondere Bedeutung zu.

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Tese de doutoramento, Farmácia (Tecnologia Farmacêutica), Universidade de Lisboa, Faculdade de Farmácia, 2016

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Este estudo pretende (1) encontrar a prevalência da Perturbação do Desenvolvimento da Coordenação (PDC) em crianças com Perturbação de Hiperatividades e Défice de Atenção (PHDA); (2) analisar qual a prevalência de défices de memória de trabalho verbal e não-verbal, em crianças com PHDA e comparar o desempenho entre as crianças que só apresentam PHDA e aquelas que apresentam também PDC; (3) verificar se a ocorrência de PDC é agravada, de acordo com a presença ou ausência de alterações de memória de trabalho e se estas podem ser consideradas fatores de risco ou de proteção para a manifestação de PDC, enquanto comorbilidade de PHDA. Foram selecionadas 37 crianças com diagnóstico de PHDA, com idades compreendidas entre os 7 e os 14 anos. A componente motora foi avaliado com a versão curta do Bruininks-Oseretsky Test of Motor Proficiency (BOTMP) e o Questionário de Perturbação do Desenvolvimento da Coordenação 2007 (DCDQ’07); a memória de trabalho foi avaliada através da Figura Complexa de Rey, Trail Making Test - parte B e Memória de Dígitos – sentido inverso. Para determinar o impacto da memória de trabalho na componente motora, recorreu-se a uma regressão logística. Encontrou-se uma prevalência de PDC de 51% e de défices ao nível da memória de trabalho verbal e não-verbal de 60% e 80%, respetivamente, para a amostra total de crianças com PHDA. A terapêutica farmacológica para a PHDA revelou-se fator protetor para a manifestação de PDC, principalmente quando a primeira se encontra associada com o nascimento de termo. Um mau desempenho no teste Memória de Dígitos – sentido inverso é fator de risco para a manifestação de PDC, em crianças com PHDA. Este estudo permitiu verificar que crianças com PHDA+PDC apresentam défices motores genuínos, característicos de manifestação de PDC. Parecem também existir relações bastante complexas entre a memória de trabalho e os mecanismos de controlo motor na PHDA, sendo que estes podem ser distintos quando está presente uma comorbilidade de PDC.