3 research outputs found
Mechanisms and kinetic profiles of superoxide-stimulated nitrosative processes in cells using a diaminofluorescein probe
AbstractIn this study, we examined the mechanisms and kinetic profiles of intracellular nitrosative processes using diaminofluorescein (DAF-2) as a target in RAW 264.7 cells. The intracellular formation of the fluorescent, nitrosated product diaminofluorescein triazol (DAFT) from both endogenous and exogenous nitric oxide (NO) was prevented by deoxygenation and by cell membrane-permeable superoxide (O2−) scavengers but not by extracellular bovine Cu,Zn-SOD. In addition, the DAFT formation rate decreased in the presence of cell membrane-permeable Mn porphyrins that are known to scavenge peroxynitrite (ONOO−) but was enhanced by HCO3−/CO2. Together, these results indicate that nitrosative processes in RAW 264.7 cells depend on endogenous intracellular O2− and are stimulated by ONOO−/CO2-derived radical oxidants. The N2O3 scavenger sodium azide (NaN3) only partially attenuated the DAFT formation rate and only with high NO (>120nM), suggesting that DAFT formation occurs by nitrosation (azide-susceptible DAFT formation) and predominantly by oxidative nitrosylation (azide-resistant DAFT formation). Interestingly, the DAFT formation rate increased linearly with NO concentrations of up to 120–140nM but thereafter underwent a sharp transition and became insensitive to NO. This behavior indicates the sudden exhaustion of an endogenous cell substrate that reacts rapidly with NO and induces nitrosative processes, consistent with the involvement of intracellular O2−. On the other hand, intracellular DAFT formation stimulated by a fixed flux of xanthine oxidase-derived extracellular O2− that also occurs by nitrosation and oxidative nitrosylation increased, peaked, and then decreased with increasing NO, as previously observed. Thus, our findings complementarily show that intra- and extracellular O2−-dependent nitrosative processes occurring by the same chemical mechanisms do not necessarily depend on NO concentration and exhibit different unusual kinetic profiles with NO dynamics, depending on the biological compartment in which NO and O2− interact
Development of a luminescent method for the analysis of counterfeit distilled alcoholic beverages
O presente trabalho propõe uma metodologia analÃtica capaz de
classificar bebidas alcoólicas destiladas (vodkas e whisky) em falsificadas ou
originais através da comparação dos espectros de fluorescência de varredura
sincronizada com padrões sabidamente originais e amostras adulteradas. Para
essa finalidade de classificação das amostras através dos espectros, foram
utilizadas as ferramentas quimiométricas Analise de Componentes Principais e
em seguida a Análise de Discriminantes Lineares e a Análise de Agrupamentos
Hierárquicos. Para obter o máximo de discriminação, foram estudados de
forma univariada todos os parâmetros que poderiam influenciar nos espectros
medidos das bebidas, para as vodkas foram necessários preparar as amostras
com reagentes quÃmicos para obter maior diferença espectroscópica. Esta
metodologia mostrou resultados que variam de 91,7% de correta classificação
para bebidas do tipo Vodka e de 100% para o tipo whisky dentro do universo
amostral estudado de acordo com os cálculos realizados pela Análise de
Discriminantes Lineares. Os resultados da Análise de Agrupamentos
Hierárquicos corroboraram com as classificações anteriormente obtidas,
robustecendo o método proposto neste trabalho, cabendo ressaltar que possuÃ
diversas qualidades operacionais como baixo custo e agilidade analÃticaThis work apresentation a analytical methodology can classifie alcolical
destiladed beverage (vodkas and whisky) in original or falsificate by
comparation of sincronic scanning fluorescence espectras with standards as
know original and the adulterated samples. For this finality of classification of
samples by espectras, was used the quimiometrical tools Principal Components
Analysis and follow by Linear Discriminant Analysis and Hierarchical Clustering
Analysis. For have maximum discrimination was performed a estudied
univarieted of all parameters that can influenciet in the beverage spectra, for the
vodkas was necessarie prepear samples with chemical reagentes to obtaneid
much spectroscopic differentiation. This methodology show results that have a
variation of 91,7% of correctly classification to the kind of bevarge vodka and
100% to kind whisky inside the sample universe estudied in acordal with the
calculation realized in the Linear Discriminant Analysis. The results of
Hierarchical Cluster Analysis corroborate with the classification obtained before,
strengthening the propused method in this work, and it should be noted that it
has several operational qualities, such as low cost and analytical agility.97 f
Production of papilloscopic revealing materials from industrial waste
A partir de resÃduos gerados pela indústria siderúrgica este trabalho se
propôs a produzir pós reveladores de impressões digitais com matéria-prima
reciclável. A grande maioria dos insumos utilizados na perÃcia criminal nacional
são importados, assim como os pós reveladores de impressão digital, o que
impacta negativamente nos orçamentos do Estado devido o alto custo e
flutuação de moedas estrangeiras. A possibilidade de produzir um revelador de
impressões digitais ecologicamente favorável, com baixo custo e qualidade igual
ou superior aos produtos vendidos no mercado atual foi a motivação cientÃfica
deste trabalho. Diversos óxidos de ferro são gerados desde sua obtenção na
forma mineral até sua conversão industrial em ferro atômico reduzido, para
subsequentemente ser transformado em aço, neste trabalho a hematita e a
magnetita foram os óxidos de ferro utilizados para produzir os reveladores de
impressão digital, aliado a uma resina vegetal e corantes preto/vermelho. O total
de três materiais foram produzidos e distribuÃdos para os estados federados da
república objetivando auxÃlio material em insumos, bem como, uma avaliação
por partes dos Institutos de CriminalÃstica quanto à qualidade dos produtos finais
produzidos neste trabalho. Em alguns estados os materiais desenvolvidos foram
utilizados para fins didáticos no ensino da papiloscopia, a ciência que estuda as
papilas dérmicas, suas impressões e métodos de análise. Os resultados finais
se mostraram positivos, mas poucos ajustes devem ainda ser feitos nos pós
magnéticos produzidos a partir do resÃduo industrial rico em magnetita. O pó
regular de cor preta já se encontra em uso em muitos estados da federação
através das doações da UFF, aproximadamente 10kg, documentadas e seu
processo de produção foi patenteado no INPI, já os magnéticos estão nas etapas
iniciais de validação mercadológica e de proteção intelectual. Com base nisso,
uma empresa foi criada para comercialização desses produtos, chamada de
Universo Forense. Estudo de mercado, precificação, licenças para utilização do
laboratório de pesquisa para esse fim, várias etapas foram vencidas para tornar
a empresa uma realidade, mas a solicitação da UFF para devolvermos o espaço
fÃsico pôs, momentaneamente, fim a essa empreitadaFrom trash generated by the steel industry, this work aimed to produce
fingerprint developer powders with recyclable materials. The vast majority of
inputs used in national criminal expertise are imported, as well as fingerprintrevealing
powders, which negatively impact state budgets due to the high cost
and fluctuation of foreign currencies. The possibility of producing an ecologically
favorable fingerprint developer, with low cost and quality equal or superior to the
products sold in the current market was the scientific motivation of this work.
Several iron oxides are generated from their obtaining in mineral form to their
industrial conversion in to reduced atomic iron, to subsequently be transformed
in steel, in this work hematite and magnetite were the iron oxides used to produce
fingerprint developers, allied to a vegetable resin and black/red dyes. A total of
three materials were produced and distributed to the federal states of the republic
aiming at material assistance in inputs, as well as an evaluation by the
Criminalistic Institutes regarding the quality of the final products produced in this
work. In some states, the materials developed were used for didactic purposes in
the teaching of papilloscopy, the science that studies the dermal papillae, their
impressions and methods of analysis. The final results were positive, but few
adjustments have yet to be made in the magnetic powders produced from
industrial residue rich in magnetite. The regular black powder is already in use in
many states of the federation through proven donations from the UFF and its
production process was patented at the INPI, while the magnetic powders are in
the initial stages of market validation and intellectual protection. Based on this, a
company was created to sell these products, called Universo Forense. Market
study, pricing, licenses to use the research laboratory for this purpose, several
steps were taken to make the company a reality, but UFF's request to return the
physical space momentarily put an end in to this endeavor94 f