This work is aimed to develop a stable Mg-based thermite with high iodine concentration and preliminarily set a method to test inactivation factor (IF) values of biocidal materials with proximity to the combat situation. First, Mg−I 2 composites were mechanochemically prepared and up to 10 wt% of iodine could be retained until the material heated to 265 °C. Then biocidal thermites were mechanochemically prepared using Mg−I 2 as a fuel and Ca(IO 3 ) 2 as an oxidizer. For Mg−I 2 −Ca(IO 3 ) 2 thermites, apparent aging was observed in the material with a stoichiometric fuel-to-oxidizer ratio. In heated filament ignition tests, thermites had ignition temperatures of ~760 °C and ~820 °C at heating rates of 1800 K/s and 13000 K/s, respectively, and were slightly lower than that of pure Mg. Particle combustion test showed that the thermite with more fuel fraction burned faster. A setup based on the constant volume explosion experiment was established to test the inactivation effect of biocidal materials. Results showed that pure Mg had the best inactivation effect, and IF value doesn't have a clear correlation with max pressure achieved by explosions of biocidal materials. For results within the same max pressure range, IF value is proportional to the iodine concentration within the materials. Interestingly, for Mg, IF value was exponentially changed with max pressurization rate, this leads to the unexpected high IF value of Mg. This study shows excessive iodine or oxidizer could deactivate the biocidal material, and the heat release rate may play a crucial role in biocidal performance.
This study aimed to explore the temporal associations between maternal serum iodine concentration (SIC) and common pregnancy outcomes in Chinese women. Eligible singleton pregnant women aged 20–34 years were selected, and their fasting blood samples were collected during early (T1, n = 1101) and mid-pregnancy (T2, n = 403) for SIC testing by inductively coupled plasma mass spectrometry. Multivariable linear regression indicated that log10SIC at T1 (β = −0.082), T2 (β = −0.198), and their % change (β = −0.131) were inversely associated with gestational weight gain (GWG, allp< 0.05). Maternal log10SIC at both T1 (β = 0.077) and T2 (β = 0.105) were positively associated with the Apgar score at 1 min (bothp< 0.05). Women in the third quartile (Q3) of SIC at T1 had a lower risk of small for gestational age (SGA, OR = 0.405, 95% CI: 0.198–0.829) compared with those in Q4. Restricted cubic spline regression suggested a U-shaped association between SIC and SGA risk, and SIC above 94 μg/L at T1 was the starting point for an increased risk of SGA. The risk of premature rupture of membrane (PROM) increased by 96% (OR = 1.960, 95% CI: 1.010–3.804) in Q4 compared to that in Q1. Our longitudinal data from an iodine-replete region of China indicated that high maternal SIC could restrict GWG and improve Apgar scores at delivery, but might increase the risk of SGA and PROM.Keywords:serum iodine;gestational diabetes mellitus;maternal thyroid function;gestational hypertension;birth weight;small and large for gestation age
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