70 research outputs found

    Dual-function cellulose composites for fluorescence detection and removal of fluoride

    Get PDF
    A biodegradable and robust fluorogenic cellulose material for simultaneous fluoride recognition and adsorption at environmentally significant levels is presented. The fluorescent modified cellulose (FMC) containing a boronic acid-based anthracene group as a fluorescent signaling unit displays a selective fluorescence enhancement with F−. On the other hand, Cl−, Br−, SO42−, H2PO4−and ClO4− did not induce significant changes in fluorescence. Furthermore, FMC shows excellent F− adsorption over a wide range of pH with a low dosage. Equilibrium studies demonstrate that the adsorption of F− follows the Langmuir model in an aqueous solution. While, adsorption kinetics were found to follow the pseudo-second-order model. The simplicity of the method and the ability to detect and remove fluoride in waste water is noteworthy given the problems associated with fluoride pollution in drinking water.</p

    Effects of air pollution on neonatal prematurity in guangzhou of china: a time-series study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Over the last decade, a few studies have investigated the possible adverse effects of ambient air pollution on preterm birth. However, the correlation between them still remains unclear, due to insufficient evidences.</p> <p>Methods</p> <p>The correlation between air pollution and preterm birth in Guangzhou city was examined by using the Generalized Additive Model (GAM) extended Poisson regression model in which we controlled the confounding factors such as meteorological factors, time trends, weather and day of the week (DOW). We also adjusted the co linearity of air pollutants by using Principal Component Analysis. The meteorological data and air pollution data were obtained from the Meteorological Bureau and the Environmental Monitoring Centre, while the medical records of newborns were collected from the perinatal health database of all obstetric institutions in Guangzhou, China in 2007.</p> <p>Results</p> <p>In 2007, the average daily concentrations of NO<sub>2</sub>, PM<sub>10 </sub>and SO<sub>2 </sub>in Guangzhou, were 61.04, 82.51 and 51.67 Îźg/m<sup>3 </sup>respectively, where each day an average of 21.47 preterm babies were delivered. Pearson correlation analysis suggested a negative correlation between the concentrations of NO<sub>2</sub>, PM<sub>10</sub>, SO<sub>2, </sub>and temperature as well as relative humidity. As for the time-series GAM analysis, the results of single air pollutant model suggested that the cumulative effects of NO<sub>2</sub>, PM<sub>10 </sub>and SO<sub>2 </sub>reached its peak on day 3, day 4 and day 3 respectively. An increase of 100 Îźg/m<sup>3 </sup>of air pollutants corresponded to relative risks (RRs) of 1.0542 (95%CI: 1.0080 ~1.1003), 1.0688 (95%CI: 1.0074 ~1.1301) and 1.1298 (95%CI: 1.0480 ~1.2116) respectively. After adjusting co linearity by using the Principal Component Analysis, the GAM model of the three air pollutants suggested that an increase of 100 Îźg/m<sup>3 </sup>of air pollutants corresponded to RRs of 1.0185 (95%CI: 1.0056~1.0313), 1.0215 (95%CI: 1.0066 ~1.0365) and 1.0326 (95%CI: 1.0101 ~1.0552) on day 0; and RRs of the three air pollutants, at their strongest cumulative effects, were 1.0219 (95%CI: 1.0053~1.0386), 1.0274 (95%CI: 1.0066~1.0482) and 1.0388 (95%CI: 1.0096 ~1.0681) respectively.</p> <p>Conclusions</p> <p>This study indicates that the daily concentrations of air pollutants such as NO<sub>2</sub>, PM<sub>10 </sub>and SO<sub>2 </sub>have a positive correlation with the preterm births in Guangzhou, China.</p
    • …
    corecore