Universidade Federal de Minas Gerais

About: Universidade Federal de Minas Gerais is a education organization based out in Belo Horizonte, Minas Gerais, Brazil. It is known for research contribution in the topics: Population & Immune system. The organization has 41631 authors who have published 75688 publications receiving 1249905 citations.

Highly active heterogeneous Fenton-like systems based on Fe0/Fe3O4 composites prepared by controlled reduction of iron oxides

Abstract: In this work, a new and highly active heterogeneous Fenton system based on iron metal and magnetite Fe 0 /Fe 3 O 4 composites has been prepared by controlled reduction of iron oxides. Temperature-programmed reduction experiments with H 2 showed that iron oxides, i.e. Fe 2 O 3 , FeOOH and Fe 3 O 4 , can be reduced to produce highly reactive Fe 0 /Fe 3 O 4 composites with different metal to oxide ratios as determined by Mossbauer spectroscopy and powder X-ray diffraction. Mossbauer measurements revealed that these composites are reactive towards gas phase molecules and can be oxidized rapidly by O 2 even at room temperature. The composites showed also very high activity for the Fenton chemistry, i.e. the oxidation of an organic model contaminant, the dye methylene blue, and the H 2 O 2 decomposition. The best results were obtained with the composites with 47% Fe 0 obtained by reduction of Fe 3 O 4 with H 2 at 400 °C for 2 h, which produced a very rapid discoloration with total organic carbon (TOC) removal of 75% after 2 h reaction. Conversion electron Mossbauer spectroscopy (CEMS) measurements before and after H 2 O 2 reaction showed that Fe 3 O 4 and especially Fe 0 are oxidized during the reaction. The reaction mechanism is discussed in terms of the formation of HO radicals by a Haber–Weiss initiated by an efficient electron transfer from the composite Fe 0 /Fe 3 O 4 to H 2 O 2 . The higher activity of the composites compared to the pure Fe 0 and iron oxides has been explained by two possible effects, i.e. (i) a thermodynamically favorable electron transfer from Fe 0 to Fe 3 O 4 producing Fe 2+ magnetite active for the reaction and (ii) by the formation of very reactive small particle size Fe 0 and Fe 3 O 4 .

Participation of the sympathetic system in acetic acid-induced writhing in mice.

Abstract: We investigated the participation of a sympathetic component in the abdominal contortions induced by intraperitoneal injection of 0.6% acetic acid in the mouse. The beta blocker propranolol (4 mg/kg, sc) caused a small significant (19%) blockade of the contortions but strongly potentiated (greater than 80%) the effect of indomethacin (30% at 5 mg/kg, sc). Significant inhibition of writhing was also observed with sympatholytics such as guanethidine (27% at 30 mg/kg, sc) and by a specific dopamine-I antagonist, SCH 23390 (62% at 400 micrograms/kg, sc). Tyramine, which releases sympathomimetic amines, and cocaine, which partially blocks the uptake of amines, potentiated acetic acid writhing. Intraperitoneal administration of noradrenaline (187 micrograms/kg)potentiated acetic acid-induced writhing. These results are consistent with the suggestion of Nakamura and Ferreira (1) that inflammatory nociception has a dual component: one mediated by cyclooxygenase metabolites and another by sympathetic amines, possibly acting through a DA-1 type receptor.

Association between consumption of ultra-processed foods and all cause mortality: SUN prospective cohort study.

Abstract: Objective To evaluate the association between consumption of ultra-processed foods and all cause mortality. Design Prospective cohort study. Setting Seguimiento Universidad de Navarra (SUN) cohort of university graduates, Spain 1999-2018. Participants 19 899 participants (12 113 women and 7786 men) aged 20-91 years followed-up every two years between December 1999 and February 2014 for food and drink consumption, classified according to the degree of processing by the NOVA classification, and evaluated through a validated 136 item food frequency questionnaire. Main outcome measure Association between consumption of energy adjusted ultra-processed foods categorised into quarters (low, low-medium, medium-high, and high consumption) and all cause mortality, using multivariable Cox proportional hazard models. Results 335 deaths occurred during 200 432 persons years of follow-up. Participants in the highest quarter (high consumption) of ultra-processed foods consumption had a higher hazard for all cause mortality compared with those in the lowest quarter (multivariable adjusted hazard ratio 1.62, 95% confidence interval 1.13 to 2.33) with a significant dose-response relation (P for linear trend=0.005). For each additional serving of ultra-processed foods, all cause mortality relatively increased by 18% (adjusted hazard ratio 1.18, 95% confidence interval 1.05 to 1.33). Conclusions A higher consumption of ultra-processed foods (>4 servings daily) was independently associated with a 62% relatively increased hazard for all cause mortality. For each additional serving of ultra-processed food, all cause mortality increased by 18%. Study registration ClinicalTrials.gov NCT02669602.