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441.
Baulig A Poirault JJ Ausset P Schins R Shi T Baralle D Dorlhene P Meyer M Lefevre R Baeza-Squiban A Marano F 《Environmental science & technology》2004,38(22):5985-5992
Fine particulate matter present in urban areas seems to be incriminated in respiratory disorders. The aim of this study was to relate physicochemical characteristics of PM2.5 (particulate matter collected with a 50% efficiency for particles with an aerodynamic diameter of 2.5 microm) to their biological activities toward a bronchial epithelial cell line 16-HBE. Two seasonal sampling campaigns of particles were realized, respectively, in a kerbside and an urban background station in Paris. Sampled-PM2.5 mainly consist of particles with a size below 1 microm and are mainly composed of soot as assessed by analytical scanning electron microscopy. The different PM2.5 samples contrasted in their PAH content, which was the highest in the kerbside station in winter, as well as in their metal content. Kerbside station samples were characterized by the highest Fe and Cu content, which appears correlated to their hydroxyl radical generating properties measured by electron paramagnetic resonance. Particles were compared by their capacity to induce cytotoxicity, intracellular ROS production, and proinflammatory cytokine release (GM-CSF and TNF-alpha). At a concentration of 10 microg/cm2, all samples induced peroxide production and cytokine release to the similar extent in the absence of cytotoxicity. In conclusion, whereas the PM2.5 samples differ by their PAH and metal composition, they induce the same biological responses likely either due to components bioavailability and/ or interactions between PM components. 相似文献
442.
The addition of fiber to foods and beverages has been linked with greater satiety and reduced energy intakes at the next meal. However, measures of satiety can be influenced by the time interval between beverage consumption and the next meal. The objective of this study was to determine how the time interval between consumption and a subsequent test meal impacts the satiating power of a low-calorie beverage supplemented with low-viscosity pectin fiber. Forty-two participants (20 men, 22 women) each participated in 4 study sessions. Study preloads were 2 low-calorie beverages (355 mL, 8 kcal) containing either 0 g fiber (no fiber) or 8 g low-viscosity fiber (added fiber). These preloads were consumed either 90 min before lunch or 15 min before lunch. Every 15 min, participants rated hunger, desire to eat, fullness, and thirst using 100-mm visual analogue scales. A test lunch was served and plate waste was measured. Beverages with added fiber reduced energy intakes at lunch relative to those without fiber. A short delay (15 min) between beverage consumption and a subsequent meal was associated with higher satiety ratings and reduced energy intakes, regardless of fiber content. The addition of low-viscosity pectin to low-calorie beverages reduced energy intakes at the next meal, presenting a possible tool for intake regulation. A short time interval between consumption of a low-calorie beverage and a meal also increased satiety and decreased food intake, reflecting the short-lived effect of volume. 相似文献
443.
This paper presents the ability of electrostatic sprayed tin oxide (SnO2) and tin oxide doped with copper oxide (1, 2, and 4 at.% Cu) films to detect different pollutant gases, i.e., H2S, SO2, and NO2. The influence of a copper oxide dopant on the SnO2 morphology is studied using scanning electron microscopy (SEM) technique, which reveals a small decrease in the porosity and particle size when the amount of dopant is increased. The sensing properties of the SnO2 films are greatly improved by doping, i.e., the Cu-doped SnO2 films have large response to low concentration (10 ppm) of H2S at low operating temperature (100 °C). Furthermore, no cross-sensitivity to 1 ppm NO2 and 20 ppm SO2 is observed. Among the studied films, the 1 at.% Cu-doped SnO2 layer is the most sensitive in the detection of all the studied gases. 相似文献
444.
Martine Hours Laetitia Chossegros Pierrette Charnay Hélène Tardy Hoang-Thy Nhac-Vu Dominique Boisson Jacques Luauté Bernard Laumon 《Accident; analysis and prevention》2013