HYDROPHOBICITY OF CONTAMINATED SILICONE RUBBER SURFACES

Silicone rubber (SIR) shows superior performance when used outdoors, but its surface can be transformed from inherently hydrophobic to hydrophilic by the adsorption of contaminants. Al(OH)(3), Al2O3, quartz powder and active carbon were selected as authentic contaminants. Hydrophobicity of the surface was determined using contact angle measurement. The results indicate that the adsorbability of the contaminants can strongly affect the hydrophobicity of contaminated SIR surface. The increasing rate of contact angle of specimens contaminated by Al(OH)(3) was much faster than that by Al2O3 and quartz due to the adsorption of migrated low molecular weight (LMW) polydimethylsiloxanes. Specimens contaminated by active carbon could achieve surface hydrophobicity within 15 min because active carbon has high adsorbability. Surfaces of contaminated ultrapure SIR, polytetrafluoroethylene (PTFE) and glass remain hydrophilic because they contain no mobile LMW components. The addition of oligomeric polydimethylsiloxanes has little effect on the hydrophobicity of contaminants covered on SIR surface.

SYNTHESIS AND CHARACTERIZATION OF SILAZANE OLIGOMER CONTAINING 1,1,3,3,5,5-HEXAMETHYLCYCLOTRISILAZANE

A new silazane oligomer containing cyclotrisilazane was synthesized by KH-catalyzed dehydro-coupling reactions between diphenylsilane and 1,1,3,3,5,5-hexamethylcyclotrisilazane (D-3(N)).

Out-of-pocket payments and economic consequences from tuberculosis care in eastern China:income inequality

Background:Despite the availability of free tuberculosis(TB)diagnosis and treatment,TB care still generates substantial costs that push people into poverty.We investigated out-of-pocket(OOP)payments for TB care and assessed the resulting economic burden and economic consequences for those with varying levels of household income in eastern China.Methods:A cross-sectional study was conducted among TB patients in the national TB programme networks in eastern China.TB-related direct OOP costs,time loss,and coping strategies were investigated across households in different economic strata.Analysis of Variance was used to examine the differences in various costs,and Kruskal-Wallis tests were used to compare the difference in total costs as a percentage of annual household income.Results:Among 435 patients,the mean OOP total costs of TB care were USD 2389.5.In the lower-income quartile,OOP payments were lower,but costs as a percentage of reported annual household income were higher.Medical costs and costs prior to treatment accounted for 66.4 and 48.9%of the total costs,respectively.The lower the household income was,the higher the proportion of medical costs to total costs before TB treatment,but the lower the proportion of medical costs patients spent in the intensive phase.TB care caused 25.8%of TB-affected households to fall below the poverty line and caused the poverty gap(PG)to increase by United States Dollar(USD)145.6.Patients in the poorest households had the highest poverty headcount ratio(70.2%)and PG(USD 236.1),but those in moderately poor households had the largest increase in the poverty headcount ratio(36.2%)and PG(USD 177.8)due to TB care.Patients from poor households were more likely to borrow money to cope with the costs of TB care;however,there were fewer social consequences,except for food insecurity,in poor households.Conclusions:Medical and pretreatment costs lead to high costs of TB care,especially among patients from the poorest households.It is necessary to train health system staff in general hospitals to promptly identify and refer TB patients.Pro-poor programmes are also needed to protect TB patients from the medical poverty trap.

Inequity in catastrophic costs among tuberculosis-affected households in China

Background:There are limited nationally representative studies globally in the post-2015 END tuberculosis(TB)era regarding wealth related inequity in the distribution of catastrophic costs due to TB care.Under the Chinese national tuberculosis programme setting,we aimed to assess extent of equity in distribution of total TB care costs(pre-treatment,treatment and overall)and costs as a proportion of annual household income(AHI),and describe and compare equity in distribution of catastrophic costs(pre-treatment,treatment and overall)across population sub-groups.Methods:Analytical cross-seaional study using data from national TB patient cost survey carried out in 22 counties from six provinces in China in 2017.Drug-susceptible pulmonary TB registered under programme,who had received at least 2 weeks of intensive phase therapy were included.Equity was depiaed using concentration curves and concentration indices were compared using dominance test.Results:Of 1147 patients,the median cost of pre-treatment,treatment and overall care,were USD 283.5,USD 413.1 and USD 965.5,respectively.Richer quintiles incurred significantly higher pre-treatment and treatment costs compared to poorer quintiles.The distribution of costs as a proportion of AHI and catastrophic costs were significantly pro-poor overall as well as during pre-treatment and treatment phase.All the concentration curves for catastrophic costs(due to pre-treatment,treatment and overall care)stratified by region(east,middle and west),area of residence(urban,rural)and type of insurance new rural co-operative medical system[NCMS],non-NCMSalso exhibited a pro-poor pattern with statistically significant(P<0.01)concentration indices.The pro-poor distribution of the catastrophic costs due to TB treatment was significantly more inequitable among rural,compared to urban patients,and NCMS compared to non-NCMS beneficiaries.Conclusions:There is inequity in the distribution of catastrophic costs due to TB care.Universal health coverage,social protection strategies complemented by quality TB care is vital to reduce inequitable distribution of catastrophic costs due to TB care in China.

Rapid Conversion of Perhydropolysilazane into Thin Silica Coating at Low Temperature

The conversion of perhydropolysilazane(PHPS)to silica at low temperature is beneficial for its application on thermally vulnerable substrates.In this work,it is demonstrated that(3-aminopropyl)triethoxysilane(APTES)has high catalytic efficiency for the low temperature conversion of PHPS and the catalytic mechanism of APTES was suggested.The influence of temperatu re and humidity on the catalytic conversion process was investigated,and it was found that PHPS can be rapidly converted to silica in 10 min at 80℃with relative humidity of 90%.The achieved silica is mainly composed of SiNO_(3)/SiO_(3)OH and SiO_(4)structure with O/Si of 1.74 and N content of 1%.As an approach to prepare inorganic coating,the low-temperature conversion method achieves a silica coating with low volume shrinkage of 0.86%,low roughness of R_(a)=0.293 nm,high nanoindentation hardness of 3.62 GPa and modulus of 30.06 GPa,which exhibits high potentials as protective coating for va rious materials even those vulnerable to high temperature.