224 research outputs found
Hemispheric asymmetry in the sunspot cycle as a nonextensive phenomenon
The appearance of dark sunspots over the solar photosphere is not considered
to be symmetric between the northern and southern hemispheres. Among the
different conclusions obtained by several authors, we can point out that the
North-South asymmetry is a real and systematic phenomenon and is not due to
random variability. In the present work, we selected the sunspot area data of a
sample of 13 solar cycles divided by hemisphere extracted from the Marshall
Space Flight Centre (MSFC) database to investigate the behavior of probability
distributions using an out-of-equilibrium statistical model a.k.a non-extensive
statistical mechanics. Based on this statistical framework, we obtained that
the non-extensive entropic parameter has a semi-sinusoidal variation with a
period of 22 year (Hale cycle). Among the most important results, we can
highlight that the asymmetry index revealed the dominance of the
northern hemisphere against the southern one. Thus, we concluded that the
parameter can be considered an effective measure for diagnosing
long-term variations of the solar dynamo. Finally, our study opens a new
approach to investigating solar variability from the nonextensive perspective.Comment: 17 pages, 2 tables and 5 figures. Submitted to Solar Physic
Seasonality Role on the Phenolics from Cultivated Baccharis dracunculifolia
Baccharis dracunculifolia is the source of Brazilian green propolis (BGP). Considering the broad spectrum of biological activities attributed to green proplis, B. dracunculifolia has a great potential for the development of new cosmetic and pharmaceutical products. In this work, the cultivation of 10 different populations of native B. dracunculifolia had been undertaken aiming to determine the role of seasonality on its phenolic compounds. For this purpose, fruits of this plant were collected from populations of 10 different regions, and 100 individuals of each population were cultivated in an experimental area of 1800 m2. With respect to cultivation, the yields of dry plant, essential oil and crude extract were measured monthly resulting in mean values of 399 ± 80 g, 0.6 ± 0.1% and 20 ± 4%, respectively. The HPLC analysis allowed detecting seven phenolic compounds: caffeic acid, ferulic acid, aromadendrin-4′-methyl ether (AME), isosakuranetin, artepillin C, baccharin and 2-dimethyl-6-carboxyethenyl-2H-1-benzopyran acid, which were the major ones throughout the 1-year monthly analysis. Caffeic acid was detected in all cultivated populations with mean of 4.0%. AME displayed the wide variation in relation to other compounds showing means values of 0.65 ± 0.13% at last quarter. Isosakuranetin and artepillin C showed increasing concentrations with values between 0% and 1.4% and 0% and 1.09%, respectively. The obtained results allow suggesting that the best time for harvesting this plant, in order to obtain good qualitative and quantitative results for these phenolic compounds, is between December and April
Effects of land cover and air pollution on the risk of preterm births
OBJECTIVE: To evaluate the association between gestational age and green areas, urban built areas, and the concentration of particulate matter 2.5 (PM2.5) in the city of São Paulo, analyzing the irregular distribution of these areas and pollution levels above the recommended level. METHODS: The study population consisted of a cohort of live births from 2012, and data from the Live Birth Information System (Sinasc) of the city of São Paulo were used. Using satellite images and supervised classification, the distribution and quantity of green areas and built areas in the city of São Paulo was obtained, as well as the concentrations of PM2.5. Logistic regressions were used to obtain possible associations. RESULTS: The results of the study show that a lower percentage of green areas is significantly associated with a higher chance of preterm births. A higher building density was positively associated with the odds ratio for preterm birth. We did not find any significant associations between air pollution (PM2.5) and preterm births. CONCLUSIONS: The results of this study show that greener areas are less associated with preterm births when compared with less green areas.OBJETIVO: Avaliar a associação entre a idade gestacional e as áreas verdes, áreas construídas urbanas e a concentração de material particulado 2,5 (MP2,5) em São Paulo, analisando a distribuição irregular dessas áreas e os níveis de poluição acima do recomendado. MÉTODOS: A população utilizada no estudo foi a dos nascidos vivos no ano de 2012, com os dados do Sistema de Informações sobre Nascidos Vivo (Sinasc) na cidade de São Paulo. Por meio de imagens de satélites e realizando a classificação supervisionada, obtivemos a distribuição e quantidade de áreas verdes e de áreas construídas, na cidade de São Paulo, assim como as concentrações de MP2,5. Regressões logísticas foram utilizadas para obter possíveis associações. RESULTADOS: Os resultados do estudo mostram que menor percentual de áreas verdes está associado significativamente com maior chance de prematuridade. Maior densidade de construção foi associada positivamente com a razão de chance de nascimento prematuro. Não encontramos resultados significativos entre a poluição do ar (MP2,5) e prematuridade. CONCLUSÕES: Os resultados deste estudo demostraram que áreas mais verdes em relação às áreas menos verdes são menos associadas a nascimentos prematuros
Enzymatic inhibition studies of selected flavonoids and chemosystematic significance of polymethoxylated flavonoids and quinoline alkaloids in Neoraputia (Rutaceae)
Our taxonomic interest in the Neoraputia stimulated an investigation of N. paraensis searching for alkaloids. Fractions were monitored by ¹H NMR and ESI-MS/MS and only those which showed features of anthranilate alkaloids and flavonoids absent in the previous investigations were examined. Stems afforded the alkaloids flindersine, skimmianine, 8-methoxyflindersine and dictamnine; leaves yielded 3',4',7,8-tetramethoxy-5,6-(2,2-dimethylpyrano)-flavone, 3',4',5,7,8-pentamethoxyflavone, 5-hydroxy-3',4',6,7-tetramethoxyflavone, 3',4'-methylenedioxy-5,6,7-trimethoxyflavone and 5-hydroxy-3',4'-methylenedioxy-6,7-dimethoxyflavone. The alkaloids have remained undiscovered for 10 years. A number of flavonoids isolated from N. paraensis, N. magnifica, Murraya paniculata, Citrus sinensis graft (Rutaceae), Lonchocarpus montanus (Leguminosae) were evaluated for their ability to inhibit the enzymatic activity of the protein glyceraldehyde-3-phosphate dehydrogenase from Trypanosoma cruzi. Highly oxygenated flavones and isoflavone were the most actives.Nosso interesse quimiotaxonômico sobre Neoraputia nos estimulou a examinar N. paraensis, visando a busca de alcalóides. As frações foram monitoradas via RMN ¹H e ESI-EM/EM e foram analisadas somente aquelas cujos espectros apresentavam características de alcalóides do ácido antranílico e flavonóides não isolados anteriormente. Foram isolados do caule os alcalóides flindersina, skimmianina, 8-metoxiflindersina e dictamnina; das folhas os flavonóides 3',4',7,8-tetrametoxi-5,6-(2,2-dimetilpirano)-flavona, 3',4',5,7,8-pentametoxiflavona, 5-hidroxi-3',4',6,7-tetrametoxiflavona, 3',4'-metilenodioxi-5,6,7-trimetoxiflavona e 5-hidroxi-3',4'-metilenodioxi-6,7-dimetoxiflavona,. Os alcalóides do ácido antranílico não foram encontrados em dez anos. Vários flavonóides isolados de N. paraensis, N. magnifica, Murraya paniculata, enxerto de Citrus sinensis (Rutaceae) e Lonchocarpus montanus (Leguminosae) foram testados frente a gliceraldeído-3-fosfato desidrogenase de Trypanosoma cruzi, visando verificar seus potenciais em inibir a atividade da enzima. Os flavonóides polimetoxilados e um isoflavonóide foram os mais ativos.380387Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Effects of land cover and air pollution on the risk of preterm births
No artigo “Efeitos da cobertura de solo e poluição do ar no risco de nascimentos prematuros”, DOI https://doi.org/10.11606/s1518-8787.2024058005504, publicado na Revista de Saúde Pública.2024;58:08,a RSP corrige: Após as referências (página 14): Financiamento: Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp – processos 16/15989-6; 09/02186-9; 09/53931-6 e 16/26082-1). Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - processo 304277/2019-3). Contribuição dos Autores: Concepção e planejamento do estudo: TCLM, SRDMS, PHS, TM. Coleta, análise e interpretação dos dados: TCLM, JLP, WR, SRDMS, TM. Elaboração ou revisão do manuscrito: TCLM, JLP, WR, PHS, DFSF, SRDMS, TM. Aprovação da versão final: TCLM, JLP, WR, PHS, DFSF, SRDMS, TM. Responsabilidade pública pelo conteúdo do artigo: TCLM, SRDMS, TM. Conflito de Interesses: Os autores declaram não haver conflito de interesses.In the article “Effects of land cover and air pollution on the risk of preterm births”, DOI https://doi.org/10.11606/s1518-8787.2024058005504, published on the Revista de Saúde Pública.2024;58:08, RSP corrects: After references (page 14): Funding: Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp – Processes 16/15989-6; 09/02186-9; 09/53931-6 e 16/26082-1). Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq - Process 304277/2019-3). Authors’ Contribution: Study design and planning: TCLM, SRDMS, PHS, TM. Data collection, analysis, and interpreation: TCLM, JLP, WR, SRDMS, TM. Preparation or revision of the manuscript: TCLM, JLP, WR, PHS, DFSF, SRDMS, TM. Final version approval: TCLM, JLP, WR, PHS, DFSF, SRDMS, TM. Public responsibility for article content: TCLM, SRDMS, TM. Conflict of Interest: The authors declare no conflict of interest
Nanopartículas de poli-'épsilon'-caprolactona carregadas com hidrocortisona: preparação usando planejamento fatorial e sua avaliação
Polymeric-nanoparticle systems such as nanocapsules and nanospheres have a great potential in applications for nanoencapsulation of corticosteroids which show low solubility in water. The physicochemical characteristics of nanoparticle suspensions are important pre-requisites for the successful development of new dosage form. In this study, hydrocortisone-loaded poly-ε-caprolactone nanoparticles have been prepared by the interfacial deposition method. A 3-factor 2-level factorial design was used to study and optimize nanoparticles formulation. This factorial design was used to study the contrasts and effects of independent variables on particle size distribution, morphology, surface charge, drug content, entrapment efficiency and in vitro drug release profiles. The screened independent variables were: the concentration of hydrocortisone, poly-ε-caprolactone and isodecyl oleate. A High Performance Liquid Chromatography method was developed and validated for hydrocortisone quantification. Special attention was given to both absolute recovery and entrapment efficiency. The results of optimized formulations showed a narrow size distribution with a polydispersity index near to 0.200. The particle sizes were on average 109.2 and 236.5nm to nanospheres and nanocapsules, respectively. In the best formulations the zeta potential was higher than 30 mV (in module) and the absolute recovery and entrapment efficiency were higher 82% and nearly 60%, respectively. The main variables were the quantity of the polymer and of the oil. Nanoparticles observed by the Scanning Electron Microscope depicted extremely spherical shape. In vitro release studies were performed through dialysis with continuous stream. Nanocapsules and nanospheres showed a similar pure diffusion release mechanism according to Korsmeyer-Peppas’s model.CNPqCAPESFAPES
Estimatation of evapotranspiration and crop coefficient of melon cultivated in protected environment
Impactos ambientais do manejo agroecológico da caatinga no Rio Grande do Norte.
O objetivo deste trabalho foi avaliar os impactos ambientais do manejo agroecológico da caatinga, em unidades de produção familiar no Rio Grande do Norte, pelo método Ambitec de produção animal - dimensão ambiental, desenvolvido pela Embrapa Meio Ambiente. Foram avaliadas sete unidades de produção familiar, em quatro projetos de assentamentos de reforma agrária do Município de Apodi, RN. Os dados para o levantamento foram obtidos por meio de questionários aplicados aos representantes das unidades produtivas familiares, que atribuíram, a cada variável estudada, um valor que representou a alteração proporcionada pela implementação da tecnologia. Após a inserção dos coeficientes de alteração de cada variável dos indicadores por unidade de produção, o coeficiente de impacto foi automaticamente calculado por meio da planilha Ambitec. O manejo agroecológico da caatinga resultou num impacto ambiental positivo, e suas maiores contribuições foram relacionadas aos efeitos positivos dos seguintes indicadores: capacidade produtiva do solo, uso de insumos materiais, qualidade do produto e diminuição da emissão de poluentes à atmosfera. Dois indicadores geraram efeitos negativos: o uso de energia e o uso de recursos naturais. Pela superioridade dos benefícios gerados, o manejo agroecológico da caatinga é uma inovação tecnológica geradora de impactos ambientais positivos
- …