Evaluation of the Impact of Exposure To Heat and to By-Products of Combustion on the Health of Firefighters.

Firefighters are often exposed to high temperatures and by-products of combustion, which can affect their health. In this study, we assessed the impact of acute exposure of firefighters in fire simulators. Twenty male firefighters were exposed to fire simulators, and observed in four phases: pre-exposure (group 0, control) and after the end of the first (group 1), second (group 2), and fourth (group 3) weeks of training. Blood samples were collected and dosed to evaluate the response of the immune, inflammatory (C-reactive protein, IL6, and IL10), and endocrine systems (cortisone, total testosterone, free testosterone, SHBG, bioavailable testosterone, TSH, and free T4). In groups 0, 1, and 3, a thermographic evaluation was also carried out to study the temperature and body heat flow of the participants. Regarding the inflammatory process, an increase in C-reactive protein and a reduction in IL-10 were observed. With respect to hormonal markers, an increase in cortisol and reduced levels of free T4 and bioavailable testosterone were found after exposure, with recovery of testosterone levels in the final week of training. Thermoregulatory adaptation of the organism has been associated with changes in heat flow in the organism in people subjected to extreme temperatures, with emphasis on the performance of the lower limbs. Our findings demonstrate an inflammatory response with hormonal changes after exposure to fire and an adaptive response of thermal balance, which could aid understanding of the physiology of the human body in extreme situations.

Les sapeurs-pompiers (SP) sont régulièrement exposés à la chaleur et aux produits de combustion, qui peuvent avoir un retentissement sur leur santé. Nous avons évalué l'effet d'une exposition aiguë de 22 SP (tous des hommes) à incendie simulé grâce à la répétition à 4 reprises d'une même batterie d'examens (avant- T0, et à la fin des 1ère -T1 2ème - T2 et 3ème - T3 semaines d'entraînement). Des paramètres sanguins relatifs à l'inflammation et l'immunité (CRP, IL6, IL10) ainsi qu'au système endocrinien (cortisol, testostérones totale, libre et biodisponible, SHBG, TSH et T4 libre) étaient prélevés à chaque évaluation. Une étude thermographique, évaluant la température corporelle et le flux thermique corporel était réalisée à T0, T1 et T3. On constatait une augmentation de la CRP et une baisse de IL10. On observait une augmentation de la cortisolémie ainsi qu'une baisse de thyroxine libre et testostérone biodisponible, cette dernière se normalisant à T3. L'adaptation corporelle à la chaleur se traduit par une augmentation du flux thermique, en particulier aux membres inférieurs. Nous observons donc des réponses inflammatoire comme endocrinienne et une adaptation de la thermorégulation en cas d'exposition à un incendie, constatations pouvant contribuer à la compréhension de la physiologie humaine en situations extrêmes.

Mid-pregnancy poly(I:C) viral mimic disrupts placental ABC transporter expression and leads to long-term offspring motor and cognitive dysfunction.

Limited information is available about the effect of mid-pregnancy viral infections on the placental expression of efflux transporters and offspring behavior. We hypothesized that maternal exposure to polyinosinic-polycytidylic acid [poly(I:C)], a synthetic double-stranded RNA viral mimic, would impair placental cell turnover, the expression of selected ABC transporters and adult offspring behavior. C57BL/6 mice were administered poly(I:C) (10 mg/Kg;ip) or vehicle at gestational day (GD) 13.5 (mid-pregnancy). Dams were euthanized for blood collection 4 h after injection, fetal and placental collection at GD18.5 or allowed to deliver spontaneously at term. At GD 13.5, poly(I:C) induced an acute pro-inflammatory response characterized by an increase in maternal plasma levels of IL-6, CXCL-1 and CCL-2/MCP-1. At GD 18.5, poly(I:C) decreased cell proliferation/death in the labyrinthine and increased cell death in the junctional zones, characterizing a disruption of placental cell turnover. Abca1 and Abcg1 immunolabelling was decreased in the labyrinthine zone, whereas Abca1, Abcg1 and breast cancer resistance transporter (Bcrp) expression increased in the junctional zone. Moreover, adult offspring showed motor and cognitive impairments in the Rotarod and T-water maze tests. These results indicate that viral infection during mid-pregnancy may disrupt relevant placental efflux transporters, as well as placental cell turnover and offspring behavior in adult life.

Atmospheric pressure plasma pretreatment of sugarcane bagasse: the influence of biomass particle size in the ozonation process.

Atmospheric pressure O2 plasma was used to produce ozone in order to treat sugarcane bagasse as a function of particle sizes. The fixed bagasse moisture content was 50%. The delignification efficiency had small improvement due to ozonation process as a function of particle size, varying from 75 up to 80%. Few amounts of hemicellulose were removed, but the ozonation has not been affected significantly with particle size variance as well (from 30 up to 35%). The cellulose presented some losses below 1.0 mm size (8-15%) which was an unexpected result. The conversion of cellulose content into free sugar has shown a significant increase as the particle size has diminished as well. The best condition of the bagasse particle size was for 0.08 mm. For this case, a great quantity of cellulose (78.8%) was converted into glucose. Optical absorption spectroscopy was applied to determine ozone concentrations in real time where the samples with typical bagasse particle sizes equal or below to 0.5 mm had shown a better absorption of ozone in comparison with greater particle size samples.

Atmospheric pressure plasma pretreatment of sugarcane bagasse: the influence of moisture in the ozonation process.

Sugarcane bagasse samples were pretreated with ozone via atmospheric O2 pressure plasma. A delignification efficiency of approximately 80 % was observed within 6 h of treatment. Some hemicelluloses were removed, and the cellulose was not affected by ozonolysis. The quantity of moisture in the bagasse had a large influence on delignification and saccharification after ozonation pretreatment of the bagasse, where 50 % moisture content was found to be best for delignification (65 % of the cellulose was converted into glucose). Optical absorption spectroscopy was applied to determine ozone concentrations in real time. The ozone consumption as a function of the delignification process revealed two main reaction phases, as the ozone molecules cleave the strong carbon-carbon bonds of aromatic rings more slowly than the weak carbon-carbon bonds of aliphatic chains.