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Background and Purpose: Nasopharyngeal carcinoma (NPC) is one of the most common cancers in southern China and the first-line treatment is radiotherapy. Intensity-modulated radiation therapy (IMRT) can deliver high dose to cancer and low dose to normal tissue, but xerostomia is still one of the complications after IMRT. However, how the concentration of saliva electrolytes be affected by IMRT and the effects on the quality of life are still unknown. In this prospective study, 76 NPC patients were recruited from hospitals in Hong Kong to identify the change of saliva electrolytes and xerostomia-related quality of life before and after IMRT., Methods and Materials: Saliva and questionnaire were collected before IMRT, 1 month, 3 months, 6 months and 12 months after IMRT. The concentration of saliva electrolytes was detected using inductively coupled plasma-optical emission spectroscopy (ICP-OES)., Results: Saliva flow rate significantly decreased after IMRT. Decrease in the mean value of pH was observed but the difference is not statistically significant. The concentrations of potassium, iodine, and calcium decreased and chloride concentration increased after IMRT, while the concentrations of sodium, magnesium, copper or zinc were kept at the same level before and after treatment. Xerostomia-related quality of life was adversely affected by IMRT, but partially recovered after 1 year., Conclusions: Our study revealed the change of saliva electrolytes and xerostomia-related quality of life in patients undergone IMRT for NPC., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Impacts of surface wind direction, surface wind speed, surface air temperature and sunshine hours on the CH4 concentration at Lin'an regional atmospheric background station were studied based on the results from Jan. 2009 to Dec. 2011. The results revealed that the diurnal variation of atmospheric CH4 concentration presented a single-peak curve at Lin'an regional background station. The diurnal amplitude varied from 19.0 x 10(-9) to 74.7 x 10(-9), with the lowest value observed in the afternoon and the highest at dawn. The monthly mean CH4 concentrations varied from 1955.7 x 10(-9) to 2036.2 x 10(-9), with the highest concentration observed in autumn and the lowest in spring. The wind directions NE-SSE could induce higher CH4 concentrations while SW-NNW wind directions had negative effects on the observed results. The CH4 concentration turned out to be lower with higher surface wind speed. With the increase of surface air temperature or sunshine hours, the CH4 concentration went up first till reaching a peak, and then decreased.

Characteristics of Atmospheric CO2 concentration obtained by Flask measurements were analyzed at Lin'an regional background station from August 2006 to July 2009. According to the simulation results of carbon tracking model, the impact of carbon sources and sinks on CO2 concentration was evaluated in Yangtze River Delta. The results revealed that atmospheric CO2 concentrations at Lin'an regional background station were between 368.3 x 10(-6) and 414.8 x 10(-6). The CO2 concentration varied as seasons change, with maximum in winter and minimum in summer; the annual difference was about 20.5 x 10(-6). The long-term trend of CO2 concentration showed rapid growth year by year; the average growth rate was about 3.2 x 10(-6)/a. CO2 flux of Yangtze River Delta was mainly contributed by fossil fuel burning, terrestrial biosphere exchange and ocean exchange, while the contribution of fire emission was small. CO2 flux from fossil fuel burning played an important role in carbon source; terrestrial biosphere and ocean were important carbon sinks in this area. Seasonal variations of CO2 concentration at Lin'an regional background station were consistent with CO2 fluxes from fossil fuel burning and terrestrial biosphere exchange.