6 resultados para Safety testing
em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"
Resumo:
Cosmetics have been used since ancient times and, recently, their consumption has increased greatly in many countries, including brazil, which is the third largest consumer market in the world. Thus, concern for the safety and efficacy of these products should be heightened, even though these products are rarely related to adverse reactions that damage the health. Brazilian law requires manufacturers to subject their products to safety testing, to assess the possible reactions that could be caused by them (irritation, sensitization, systemic effects). To this end, in general, animals have been used as the experimental model, but this practice is being increasingly controlled, so that the scientific community is looking for alternative tests that do not require experimental in vivo models. Thus, this review aims to describe the main biological assays used to assess the safety of cosmetics, as well as in vitro assays that can replace them.
Resumo:
High-frequency ultrasound is a non-invasive tool used in skin ageing research to assess dermis thickness and echogenicity. This study evaluated the reliability of a range of high-frequency ultrasound parameters and tested their correlation with age and a validated clinical scale for the assessment of forearm skin photoageing; the difference between two body sites according to environmental exposition patterns was also investigated. Twenty-three volunteers aged 28-82 years were divided into three groups according to forearm photoageing degree. A 20 MHz ultrasound unit was used to obtain cross-sectional images of the skin by two trained investigators on two different sites: the dorsal forearm (chronically photoexposed skin) and the proximal medial arm (non-photoexposed skin). Several echogenicity parameters were studied for each skin compartment: total dermis, upper dermis and lower dermis, and the ratio between upper and lower dermis. The intraclass correlation coefficient (for complete agreement) between investigators was higher for upper and total dermis echogenicity measures compared with the lower dermis. At the non-photoexposed site, the upper and lower dermis parameter ratio was better correlated with age. At the photoexposed area, total dermis parameters demonstrated higher correlations with clinical score. The authors discuss the choice of parameters for forearm photoageing assessment using high-frequency ultrasound.
Resumo:
Cosmetics have been used since ancient times and, recently, their consumption has increased greatly in many countries, including brazil, which is the third largest consumer market in the world. Thus, concern for the safety and efficacy of these products should be heightened, even though these products are rarely related to adverse reactions that damage the health. Brazilian law requires manufacturers to subject their products to safety testing, to assess the possible reactions that could be caused by them (irritation, sensitization, systemic effects). To this end, in general, animals have been used as the experimental model, but this practice is being increasingly controlled, so that the scientific community is looking for alternative tests that do not require experimental in vivo models. Thus, this review aims to describe the main biological assays used to assess the safety of cosmetics, as well as in vitro assays that can replace them.
Resumo:
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Since the 1950s, fatigue is the most important project and operational consideration for both civil and military aircrafts. For some aircraft models the most loaded component is one that supports the motor: the Motor Cradle. Because they are considered critical to the flight safety the aeronautic standards are extremely rigorous in manufacturing them by imposing a zero index of defects on the final weld quality (Safe Life), which is 100% inspected by Non-Destructive Testing/NDT. This study has as objective to evaluate the effects of up to four successive TIG welding repairs on the axial fatigue strength of an AISI 4130 steel. Tests were conducted on hot-rolled steel plate specimens, 0.89 mm thick, with load ratio R = 0.1, constant amplitude, at 20 Hz frequency and in room temperature, in accordance with ASTM E466 Standard. The results were related to microhardness and microstructural and geometric changes resulting from welding cycles.