UV-Visible Spectroscopy Study of Oxidative Degradation of Sunflower Biodiesel

In this study, three antioxidants (blend (hydrogenated cardanol + 5-n-pentadecyl-2-tert-butylphenol), 5-n-pentadecyl-2-tert-butylphenol and ionol BF200) were evaluated for their potential to reduce the degree of oxidation of sunflower biodiesel under thermal stress condition. Each antioxidant was added at a concentration of 1000 ppm. The oxidative degradation was investigated by UV-visible spectroscopy and iodometry were used to monitor the changes using peroxide values. The results showed that, blend and 5-n-pentadecyl-2-tert-butylphenol possess significant potentiality when compared with ionol BF200. The blend and 5-n-pentadecyl-2-tert-butylphenol reduced the absorbance around 31%. The peroxide value showed that, the formulations: sunflower biodiesel/A2, sunflower biodiesel/A3 and sunflower biodiesel/AC showed better results when compared with sunflower biodiesel without antioxidant.Keywords: Antioxidants; Peroxide value; Accelerated oxidation tes

Inbreeding levels in Northeast Brazil: Strategies for the prospecting of new genetic disorders

A new autosomal recessive genetic condition, the SPOAN syndrome (an acronym for spastic paraplegia, optic atrophy and neuropathy syndrome), was recently discovered in an isolated region of the State of Rio Grande do Norte in Northeast Brazil, in a population that was identified by the IBGE (Brazilian Institute of Geography and Statistics) as belonging to the Brazilian communities with the highest rates of “deficiencies” (Neri, 2003), a term used to describe diseases, malformations, and handicaps in general. This prompted us to conduct a study of consanguinity levels in five of its municipal districts by directly interviewing their inhabitants. Information on 7,639 couples (corresponding to about 40% of the whole population of the studied districts) was obtained. The research disclosed the existence of very high frequencies of consanguineous marriages, which varied from about 9% to 32%, suggesting the presence of a direct association between genetic diseases such as the SPOAN syndrome, genetic drift and inbreeding levels. This fact calls for the introduction of educational programs for the local populations, as well as for further studies aiming to identify and characterize other genetic conditions. Epidemiological strategies developed to collect inbreeding data, with the collaboration of health systems available in the region, might be very successful in the prospecting of genetic disorders

Interferon-gamma and granulocyte/monocyte colony-stimulating factor production by natural killer cells involves different signaling pathways and the adaptor stimulator of interferon genes (STING)

Natural killer (NK) cells are important for innate immunity in particular through the production of IFN-gamma and GM-CSF. Both cytokines are important in restoration of immune function of tolerized leukocytes under inflammatory events. The expression of TLRs in NK cells has been widely studied by analyzing the mRNA of these receptors, rarely seeking their protein expression. We previously showed that murine spleen NK cells express TLR9 intracellularly and respond to CpG oligodeoxynucleotide (CpG-ODN) by producing IFN-gamma and GM-CSF. However, to get such production the presence of accessory cytokines (such as IL-15 and IL-18) was required, whereas CpG-ODN or accessory cytokines alone did not induce IFN-gamma or GM-CSF. We show here that TLR9 overlaps with the Golgi apparatus in NK cells. Furthermore, CpG-ODN stimulation in the presence of accessory cytokines induces the phosphorylation of c-Jun, STAT3, and IkappaBalpha. IFN-gamma and GM-CSF production requires NF-kappaB and STAT3 activation as well as Erk-dependent mechanisms for IFN-gamma and p38 signaling for GM-CSF. Using knock-out-mice, we show that UNC93b1 and IL-12 (produced by NK cells themselves) are also necessary for IFN-gamma and GM-CSF production. IFN-gamma production was found to be MyD88- and TLR9-dependent, whereas GM-CSF was TLR9-independent but dependent on STING (stimulator of interferon genes), a cytosolic adaptor recently described for DNA sensing. Our study thereby allows us to gain insight into the mechanisms of synergy between accessory cytokines and CpG-ODN in NK cells. It also identifies a new and alternative signaling pathway for CpG-ODN in murine NK cells

DEP–DM: Uma Abordagem baseada em Ensemble Regression para o Diagnóstico de Problemas Educacionais

Este artigo apresenta a abordagem DEP-DM, baseada em modelos Ensemble Regression para o diagnóstico do problema do desempenho escolar dos estudantes das escolas públicas de Pernambuco. O estudo baseou-se em informações do SAEB do ano de 2013. O conhecimento foi extraído por meio da abordagem proposta, sendo possível identificar os fatores associados e estabelecer as relações de causa e efeito com o problema do desempenho escolar. Por fim, foram aplicados modelos de regressão paramétricos e não paramétricos para a previsão desse desempenho. Os resultados e diagnóstico apresentam que os fatores relacionados a infraestrutura da escola, ensino e familiares, exercem forte influência sobre o desempenho escolar

INVESTIGAÇÃO DOS PARÂMETROS FOTOELETROCATALÍTICOS DO m-BiVO4 NA OXIDAÇÃO DE GLICOSE

This work aims to evaluate the behavior of the FTO/m-BiVO4 photoanode in different electrolytes, pH, anions and cations, in order to investigate the influence of these parameters on their photoelectrochemical activity. The m-BiVO4 semiconductor was developed by combustion synthesis in solution (SCS) and deposited by dip-coating technique on fluorinated doped tin oxide (FTO) coated glass substrate. The morphological and structural characterization of the film was performed by XRD, UV-Vis and SEM measurements. The evaluation of the photosensitive behavior of the film was made by linear voltammetry and chronoamperometry in the presence of pulsed visible light. After photoelectrochemical parameters optimization, the study of photoelectrocatalysis in glucose degradation was performed. Thus, it was possible to evaluate the efficiency of the film in the photoelectrocatalytic processes, presenting itself as a potential material for such applications.Este trabalho visa avaliar o comportamento do fotoanodo FTO/m-BiVO4 em diferentes eletrólitos, pH, ânions e cátions, a fim de investigar a influência desses parâmetros na sua atividade fotoeletroquímica. O semicondutor m-BiVO4 foi desenvolvido pela síntese de combustão em solução (SCS) e depositado através da técnica de dip-coating em substrato de vidro condutor revestido com óxido de estanho dopado com flúor (FTO). A caracterização morfológica e estrutural do filme foi realizada por medidas de DRX, UV-Vis e MEV. A avaliação do comportamento fotossensível do filme foi feita por voltametria linear e cronoamperometria na presença de luz visível pulsada. Após otimização dos parâmetros fotoeletroquímicos, foi realizado o estudo da fotoeletrocatálise na degradação de glicose. Assim, foi possível avaliar a eficiência do filme nos processos fotoeletrocatalíticos, apresentando-se como um potencial material para tais aplicações