RESUMEN

This work measured the δ13C and δ15N signatures in PM2.5 and size-segregated particles emitted from incense stick and cigarette burning in different brands or nicotine contents for pollution source identification indoors. Three popular brands of incense stick and cigarette were selected for experiments. A personal environmental monitoring sampler and a Sioutas cascade impactor were used to collect PM2.5 and size-segregated particles, respectively, for isotopic signatures analyses. Our data showed that both δ13C and δ15N values were heavier from incense stick burning (δ13C: 27.3 ± 0.5; δ15N: 8.63 ± 1.35) than cigarette (δ13C: 28.5 ± 0.2; δ15N: 4.15 ± 0.69). The scatter plots of δ13C and TC/PM2.5 and of δ15N and TN/PM2.5 can be applied to distinguish particle pollution sources and assess the influence of cigarette burning to PM2.5 according to different nicotine contents. The δ13C values in size-segregated particles were similar to incense stick or cigarette burning; the δ13C values in PM2.5 were significantly higher than those in size-segregated particles. However, the nitrogen amount was too low in most of the size-segregated particles to analyze δ15N from incense stick and cigarette burning. These results suggest that the δ13C signatures on PM2.5 cannot represent the isotopic characteristics of size-segregated particles and δ15N has limitation for pollution source identification of different particle sizes.

Asunto(s)

Contaminantes Atmosféricos , Contaminación del Aire Interior , Productos de Tabaco , Contaminantes Atmosféricos/análisis , Contaminación del Aire Interior/análisis , Monitoreo del Ambiente , Isótopos , Nicotina , Tamaño de la Partícula , Material Particulado/análisis

RESUMEN

Uric acid stone is the most comment radiolucent renal stone with high recurrence rate, which would further cause acute upper urinary tract obstruction and kidney failure. Here we report two cases of renal uric acid stone from December 2012 to April 2013. One 43-year-old male patient suffered from chronic uric acid nephrolithiasis caused by the long-term indwelling of bilateral double-J stent. Another 69-year-old patient was also diagnosed with uric acid nephrolithiasis at the right kidney. Both patients were first treated with extracorporeal shock wave lithotripsy (ESWL), followed by 1.5% sodium bicarbonate dissolution therapy. After a week of the treatment, the uric acid stones in both patients were completely dissolved without retrograde infection. In summary, the use of ESWL and sodium bicarbonate dissolution therapy as a combined modality is a safe, effective, inexpensive treatment for uric acid nephrolithiasis.