RESUMO
Excessive UV solar radiation exposure causes human health risks; therefore, the study of multifunctional filters is important to skin UV protective ability and also to other beneficial activities to the human organism, such as reduction of reactive oxygen species (ROS) responsible for cellular damages. Potential multifunctional filters were obtained by intercalating of ferulate anions into layered simple metal hydroxides (LSH) through anion exchange and precipitation at constant pH methods. Ultrasound treatment was used in order to investigate the structural changes in LSH-ferulate materials. Structural and spectroscopic analyses show the formation of layered materials composed by a mixture of LSH intercalated with ferulate anions, where carboxylate groups of ferulate species interact with LSH layers. UV-VIS absorption spectra and in vitro SPF measurements indicate that LSH-ferulate systems have UV shielding capacity, mainly UVB protection. The results of reactive species assays show the ability of layered compounds in capture DPPHâ¢, ABTSâ¢+, ROOâ¢, and HOCl/OCl- reactive species. LSH-ferulate materials exhibit antioxidant activity and singular optical properties that enable their use as multifunctional filters.
Assuntos
Hidróxidos/química , Protetores contra Radiação/química , Raios Ultravioleta/efeitos adversos , Zinco/química , Ânions/química , Antioxidantes/efeitos da radiação , Humanos , Substâncias Intercalantes/química , Metais/química , Espécies Reativas de Oxigênio/química , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Sistema Solar/química , Análise EspectralRESUMO
Resumo O objetivo do artigo é divulgar as fotografias astronômicas feitas pela expedição brasileira enviada a Sobral para registrar o eclipse total do Sol de 29 de maio de 1919. Uma rica coleção de fotografias, na maioria inéditas, disponíveis em suporte de placas de vidro, encontra-se na Biblioteca do Observatório Nacional. A fotografia ocupou lugar central na astronomia do século XX. O eclipse de Sobral ganhou repercussão mundial devido à comprovação da teoria da relatividade geral pelas expedições inglesas. Neste texto ressaltamos a participação dos astrônomos do Observatório Nacional no evento, pois foram os primeiros brasileiros a ter sucesso na obtenção de fotografias da coroa solar.
Abstract The objective of this article is to disseminate the astronomical photographs taken by the Brazilian expedition sent to Sobral (state of Ceará) to record the total eclipse of the Sun on May 29, 1919. There is a rich collection of photographs, most unpublished, available on glass plates stored in the Library of the Observatório Nacional. Photography was central to astronomy in the twentieth century. Thus, while the eclipse in Sobral had worldwide repercussions due to the proof of the theory of general relativity by the English expeditions, in this article we highlight the participation of astronomers from the Observatório Nacional at the same event, since they were the first Brazilians to successfully obtain photographs of the Sun's corona.
Assuntos
Astronomia , Sistema Solar , Imagem Eidética , Fotografia , Brasil , História do Século XXRESUMO
Resumen El artículo analiza las taxonomías digitales desde la perspectiva bibliotecológica. Su objetivo fue construir una taxonomía digital del área de conocimiento "Sistema solar" que pudiera ser implementada como sistema de acceso temático jerárquico-visual para un conjunto de recursos de información digitales albergados en un sitio web. La metodología empleada en la construcción de la taxonomía consistió en una propuesta particular que se nutre de dos metodologías relevantes sobre el tema. Se encontró que las taxonomías son un Sistema para la Organización del Conocimiento (SOC) que, debido a su potencial representador y organizador, han migrado al espacio de los Sistemas para la Organización del conocimiento en Red (SOCR) cuyas funciones en la web están asociadas, entre muchas aplicaciones, a la indización y clasificación de recursos de información. Se concluye que el conocimiento teórico y aplicado de las taxonomías digitales es prioritario para los profesionales de la información que día a día se enfrentan a más retos relacionados con el ordenamiento de recursos de información insertos en la World Wide Web.
Abstract The article analyzes digital taxonomies from the librarianship perspective. Its objective was to build a digital taxonomy about "Solar System" knowledge area that can be implemented as hierarchical-visual subject access system for a set of digital information resources stored in a website. The methodology used to build the taxonomy was a proposal based on two relevant methodologies about the topic. It was found that taxonomies are a Knowledge Organization Systems (KOS) that, due to its representational and organizer potential, have migrated to the space of Networked Knowledge Organization Systems (NKOS), whose tasks on the web are associated, among many applications, to the indexing and classification of information resources. It is concluded that the theoretical and applied knowledge of digital taxonomies is a priority for information professionals who every day deals with challenges related to the organization of information sources inserted in the World Wide Web.
Assuntos
Armazenamento e Recuperação da Informação , Classificação/métodos , Vocabulário Controlado , Sistema Solar , Análise DocumentalRESUMO
In the present study, we observed that Leptinaria unilamellata responds to changes in microclimatic conditions through shifts in shell morphology. Over three laboratory generations, shell differences between two populations, representing distinct morphotypes, became less evident. Only F1 generations from both populations showed shell morphometry very similar to the field parental snails, suggesting maternal effect. Snails from the locality with higher values of rainfall, relative humidity and evaporation index and smaller values of temperature and insolation produced more and larger hatchlings. Snails from the locality with less favorable climatic conditions presented shells traits that offer protection against desiccation, but reduce reproductive success. These snails showed smaller offspring production and faster response to a desiccation regime, through changes in conchiometrics. In addition, the results of the present study suggest that the spire index plays a less important role in determining protective properties of the shell of L. unilamellata, in response to desiccation risk, compared to aperture dimension. As shell aperture dimension is an important trait related to resistance to desiccation, and at the same time to reproduction, plastic responses to environmental conditions promoting the balance between survival and reproductive success are critical for the species adaptive success.
Assuntos
Exoesqueleto/anatomia & histologia , Microclima , Caramujos/fisiologia , Animais , Brasil , Desidratação , Umidade , Chuva , Reprodução/fisiologia , Caramujos/anatomia & histologia , Sistema SolarRESUMO
Naturally fermented and sundried tapioca starch is reportedly the traditional material for polvilho azedo and the primary ingredients of gluten-free food items in Brazil. This study aimed to investigate starch structure and expansion rate, high rate is acclaimed in baking application, changes of tapioca starch and potato starch during combinatorial fermentation and drying. The rate of expansion changed from 3.37â¯mL/g in native tapioca starch to 3.71â¯mL/g in fermented oven-dried tapioca starch and 6.97â¯mL/g in fermented sun-dried tapioca starch, while potato starch sample displayed lesser expansion on all treatments. Rapid viscosity analysis, size-exclusion chromatography, X-ray diffraction (XRD), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) and electron paramagnetic resonance spectrometry (EPR) were performed to determine the structure and investigate its relationship with the expansion rate. Fermentation attacked amorphous area and cleaved glycosidic bonds. Sunlight exposure facilitated complex interactions, and crosslinking increased the molecular weight distribution (MWD) in fermented sun-dried potato starch and led to depolymerization in tapioca starch. EPR revealed an initial free radical distribution in both starches, and our results show that intensity changes in tapioca starch are essential for a high expansion capacity.
Assuntos
Dessecação/métodos , Fermentação , Manihot/química , Solanum tuberosum/química , Amido/química , Amilopectina/química , Brasil , Alimentos Fermentados , Glutens , Lactobacillus plantarum , Peso Molecular , Sistema Solar , ViscosidadeRESUMO
BACKGROUND: Several studies have shown that the incidence of benign paroxysmal positional vertigo (BPPV) presents seasonal variations and there is evidence that the variation in time is dependent on the patient's amount of vitamin D. OBJECTIVES: This is a retrospective study to verify if there is a correlation between the incidence of BPPV and the level of solar radiation, essential for the synthesis of vitamin D in the skin. MATERIAL AND METHODS: This study comprised 214 patients with BPPV seen from 2012 to 2017, in a city Latitude: -30.0277, Longitude: -51.2287 30° 1' 40â³ South, 51° 13' 43â³ West. The amounts of monthly solar radiation were analyzed in relation to the dates of their first consultations. Statistical tests were employed to verify the existence of a correlation between solar radiation and the incidence of the disease. RESULTS: The statistical analysis revealed a significant difference between the incidence of BPPV and the amount of radiation during the month of the diagnosis of the disease. There was also a significant statistical correlation with the climatic variation. CONCLUSION: More patients with benign paroxysmal positional vertigo (BPPV) are seen in consultation in the months with low solar radiation and in the autumn and winter seasons, in this geographic city.
Assuntos
Vertigem Posicional Paroxística Benigna/diagnóstico , Vertigem Posicional Paroxística Benigna/epidemiologia , Estações do Ano , Raios Ultravioleta , Deficiência de Vitamina D/epidemiologia , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Sistema Solar , Vitamina D/sangue , Deficiência de Vitamina D/diagnósticoRESUMO
OBJECTIVE: To confirm prior findings that the larger the maximum monthly increase in solar insolation in springtime, the younger the age of onset of bipolar disorder. METHOD: Data were collected from 5536 patients at 50 sites in 32 countries on six continents. Onset occurred at 456 locations in 57 countries. Variables included solar insolation, birth-cohort, family history, polarity of first episode and country physician density. RESULTS: There was a significant, inverse association between the maximum monthly increase in solar insolation at the onset location, and the age of onset. This effect was reduced in those without a family history of mood disorders and with a first episode of mania rather than depression. The maximum monthly increase occurred in springtime. The youngest birth-cohort had the youngest age of onset. All prior relationships were confirmed using both the entire sample, and only the youngest birth-cohort (all estimated coefficients P < 0.001). CONCLUSION: A large increase in springtime solar insolation may impact the onset of bipolar disorder, especially with a family history of mood disorders. Recent societal changes that affect light exposure (LED lighting, mobile devices backlit with LEDs) may influence adaptability to a springtime circadian challenge.