Trichloroanisole (TCA) is one of the most significant contaminants in cork stoppers. The presence of TCA leads to an unpleasant odor known as cork taint, resulting in high economic losses for the ...cork and wine industries. Hence, the detection, quantification, and characterization of TCA are essential to address this concern. The present study investigates the electron-driven fragmentation pathways of TCA through electron ionization mass spectrometry as a function of electron energy (0100 eV), and the results are supported by theoretical characterization of ionization potentials, dissociation thresholds, and electron ionization cross sections. The appearance energies of ten cations were measured, including the first experimental evaluation of the molecule's ionization energy at 8.8 0.3 eV, in excellent agreement with the calculations (8.83 eV). For lower energies, around 20 eV, the parent cation accounted for more than 60% of the total ion signal, followed by its demethylated fragment. Taken together, these ion signals could be used as fingerprints of TCA in industrial quality control by low-energy electron ionization mass spectrometry. Fifty other fragments have been identified at higher electron energies, revealing the very rich fragmentation pattern of TCA.
This work probes electron-driven ionization of TCA. New fragment ions are identified by mass spectrometry and experimental appearance energies show excellent agreement with calculated threshold energies for the most significant pathways.
Industrial capacity planning in oligopolistic markets Vieira, Leonardo Augusto dos Santos; Mayerle, Sergio Fernando; Vieira, Carolina Luisa dos Santos ...
Optimization and engineering,
12/2016, Letnik:
17, Številka:
4
Journal Article
Recenzirano
Available productive capacity is determinant of a company’s success once it allows meeting the current and future demand. This article proposes a quantitative model for determining long-term ...productive capacity in competitive oligopolistic markets, based on the Nash Equilibrium formulated as a Variational Inequality problem. Numerical examples enable an analytical evaluation of the economic equilibrium’s sensitivity to marginal costs, investment costs, hurdle rate, and market saturation. Results show that, in order to achieve a greater market share, it is important to adopt strategies that reduce marginal costs. On the other hand, variations in the hurdle rate may or may not reinforce the position of a competitor in the market and his interest in investing in capacity expansion. Additionally, market saturation may be achieved, beyond which investment becomes unattractive. Each of these is a positive outcome for society, triggering diversified investments and competition in economic sectors where competition is low and profits are high.
Hepatitis A virus (HAV) and hepatitis E virus (HEV) are both transmitted by the faecal-oral route, and represent common causes of acute hepatitis in developing countries. The endemicity of HAV ...infection has shifted from high to moderate in Brazil. Human cases of HEV infection seem to be rare, although the virus has been detected in swine livestock and effluents of slaughterhouses. This study was to determine the epidemiology of hepatitis A and E in one of the largest agricultural settlements in the Amazon Basin of Brazil.
Serum samples collected from 397 individuals aged between 5 and 90 years during a population-based cross-sectional survey were tested for anti-HAV and anti-HEV antibodies. Associated risk factors and spatial clustering of HAV and HEV seropositivity were also analyzed.
The overall rate of HAV seropositivity was 82.9% (95% confidence interval (CI), 79.2-86.6%). Multilevel logistic regression analysis identified increasing age (in years; odds ratio (OR), 1.097; 95% CI, 1.050-1.147; P < 0.001) and crowding (OR, 1.603; 95% CI, 1.054-2.440; P = 0.028) as significant risk factors for HAV seropositivity. Anti-HEV IgG was detected in 50/388 settlers (12.9%, 95% CI, 9.5-16.2%). Anti-HEV IgM was detected in 7/43 (16.3%) anti-IgG positive samples, and 4 of them had a confirmed result by immunoblot. Increasing age was the only significant determinant of HEV seropositivity (OR, 1.033; 95% CI, 1.016-1.050; P < 0.001). No significant spatial clustering of HAV and HEV seropositivity was detected in the area.
Both HAV and HEV are endemic, with differing rates of infection in children and adults in this rural setting of the Brazilian Amazon. Anti-HEV prevalence was considerably higher than those previously reported in Brazil. The detection of HEV- specific IgM antibodies in four asymptomatic individuals is highly suggestive of the circulation of HEV in this rural population.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background & Aims This study examined whether the regulation of resistin and visfatin could reduce damage and improve regeneration in both steatotic and non-steatotic livers undergoing partial ...hepatectomy under ischemia-reperfusion, a procedure commonly applied in clinical practice to reduce bleeding. Methods Resistin and visfatin were pharmacologically modulated in lean and obese animals undergoing partial hepatectomy under ischemia-reperfusion. Results No evident role for these adipocytokines was observed in non-steatotic livers. However, obese animals undergoing liver surgery showed increased resistin in liver and plasma, without changes in adipose tissue, together with visfatin downregulation in liver and increment in plasma and adipose tissue. Endogenous resistin maintains low levels of visfatin in the liver by blocking its hepatic uptake from the circulation, thus regulating the visfatin detrimental effects on hepatic damage and regenerative failure. Indeed, the administration of anti-resistin antibodies increased hepatic accumulation of adipocyte-derived visfatin, exacerbating damage and regenerative failure. Interestingly, treatment with anti-visfatin antibodies protected steatotic livers, and similar results were obtained with the concomitant inhibition of resistin and visfatin. Thus, when visfatin was inhibited, the injurious effects of anti-resistin antibodies disappeared. Herein we show that upregulation of visfatin increased NAD levels in the remnant steatotic liver, whereas visfatin inhibition decreased them. These later observations suggest that visfatin may favour synthesis of NAD instead of DNA and induces alterations in amino acid metabolism-urea cycle and NO production, overall negatively affecting liver viability. Conclusions Our results indicate the clinical potential of visfatin blocking-based therapies in steatotic livers undergoing partial hepatectomy with ischemia-reperfusion.
This study focuses on the rational use of medicines (RUM) by hypertensive and/or diabetic patients treated in primary health care units in the city of Rio de Janeiro. It involves a cross-sectional ...study conducted between January and February 2010. Indicators were created considering the following aspects: adherence to prescribed medicine, self-medication and how patients store medicines within their households. Univariate and multivariate data analysis was performed. Of the 547 patients studied, 77.5% reported that they usually take the entire course of medicines and 80.3% reported that they tend not to forget to take them. Almost all respondents reported that they only take medications prescribed by authorized health professionals. Half of the patients had no expired medicines or damaged medicine packages in the home. Statistical tests revealed that RUM is higher among hypertensive individuals who are married and working, who mention receiving medical guidance about diet and physical exercise, and who have not missed any scheduled medical appointments at the primary health care unit within the 6 months before this research was conducted. The findings emphasize the importance of primary health care in promoting the rational use of medicines.
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