Investigation and analysis of indoor radon concentration of urban residents in Shiyan, China / 中国辐射卫生

@#<b>Objective</b> To monitor the indoor radon concentration of urban residents in Shiyan, China, and to analyze the related influencing factors. <b>Methods</b> From April to July, 2019, RSKS standard detectors were used to measure the indoor radon concentration of 125 households in Shiyan, and the results were analyzed. <b>Results</b> The indoor radon concentration of residents in Shiyan showed a skewed distribution, ranging from 13.8 to 145 Bq/m³, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 38.3 (29.0,62.0) Bq/m³. The estimated annual effective dose of radon and radon daughters from inhalation was 0.52-5.50 mSv, and <i>M</i> (<i>P</i>₂₅,<i>P</i>₇₅) was 1.45 (1.10, 2.36) mSv, which was consistent with literature. Building structure (<i>H</i> = 14.10, <i>P</i> < 0.001), floor (<i>H</i> = 24.41, <i>P</i> < 0.001), and geographical region (<i>H</i> = 8.963, <i>P</i> < 0.05) were influencing factors of indoor radon concentration, and the differences were significant. <b>Conclusion</b> The indoor radon concentration of urban residents in Shiyan is lower than the national standard limit. However, in daily life, it is still necessary to take appropriate measures to reduce the concentration of indoor radon as much as possible.

Applications of different solvents and conditions for differential extraction of lipopolysaccharide in Gram-negative bacteria.

Lipopolysaccharide (LPS) is one of the major components in the outer membrane of Gram-negative bacteria. However, its heterogeneity and variability in different bacteria and differentiation conditions make it difficult to extract all of the structural variants. We designed a solution to improve quality and biological activity of LPS extracted from various bacteria with different types of LPS, as compared to conventional methods. We introduced a quality index as a simple measure of LPS purity in terms of a degree of polysaccharide content detected by absorbance at 204 nm. Further experiments using gel electrophoresis, endotoxin test, and macrophage activation test were performed to evaluate the performance and reliability of a proposed 'T-sol' method and the biological effectiveness and character of the LPS products. We presented that the T-sol method had differential effects on extraction of a RAW 264.7 cell-activating LPS, which was effective in the macrophage activation with similar effects in stimulating the production of TNF-alpha. In conclusion, the T-sol method provides a simple way to improve quality and biological activity of LPS with high yield.