Kesterite Cu2ZnSnSe4 (CZTSe) thin films prepared by the selenization of mechanochemically synthesized Cu2ZnSnS4 (CZTS) nanocrystal films are systematically investigated as a function of the annealing ...time in terms of the phase purity, microstructure, composition, and device characteristics. It is shown that selenization for an extended time does not cause a noticeable amount of Sn loss or segregation of Zn-rich layers. Thus, the prolonged annealing leads to improvements (reduction) in the shunt conductance, reverse saturation current, and diode ideality factor. However, it also leads to a deterioration of the series resistance, of which influence turned out to overwhelm all of the aforementioned positive effects on the device performance. As a consequence, the CZTSe solar cell exhibits its highest efficiency (5.43%) at the shortest annealing time (10 min). Impedance spectroscopy is demonstrated to be of good use in detecting the change in the back contact of CZTSe solar cells during annealing. The impedance spectra of the CZTSe solar cells are analyzed in association with the microstructures of the back-contact electrodes, demonstrating that the increase in the series resistance is attributed to the formation of the resistive MoSe2 layer.
The emission of volatile organic compounds (VOCs) resulting from outdoor air pollution can contribute to major public health problems. However, there has been limited research on the health effects ...in humans from the inhalation of VOCs. Therefore, this study conducted an in vivo analysis of the effects of toluene, one of the most commonly used chemicals in many industries, on gene expression and methylation over time using the high-throughput technique of microarray analysis. We separated participants into three groups (control, short-term exposure, and long-term exposure) to investigate the influence of toluene exposure time on gene expression. We then comprehensively analyzed and investigated the correlation between variations in gene expression and the occurrence of methylation. Twenty-six genes were upregulated and hypomethylated, while 32 genes were downregulated and hypermethylated. The pathways of these genes were confirmed to be associated with cell survival and the immune system. Based on our findings, these genes can help predict the effects of time-dependent exposure to toluene on human health. Thus, observations from our data may have implications for the identification of biomarkers of toluene exposure.
•We identified health risks of toluene exposure based on the exposure length.•We examined expression levels with methylation patterns in time-dependent manner.•Fifty-eight genes are discussed in this in vivo sample study.
Objective To examine the occurrence of ureteral stent failure in pediatric patients aged <10 years and to determine risk factors for failure. Methods We performed a retrospective cohort analysis of ...100 patients who underwent ureteral stent insertion between January 2006 and December 2013. All patients were aged <10 years and were followed up until ureteral stent removal. Information regarding patient demographics, reason for stent insertion, duration of stent maintenance, stent diameter and length, and postoperative results was collected. Risk factors for stent failure were analyzed. Results Ureteral stenting was performed in 114 ureter units. The median age at stenting was 34.1 months (interquartile range IQR, 8.1-71.2 months), and the median duration of stent maintenance was 35.0 days (IQR, 21.0-44.3 days). A 3-Fr stent was used in 39.5% of patients. Stent failure was observed in 11 ureter units (9.6%) at a median of 11.5 days (IQR, 7.8-24.5 days) after insertion, and the stent was subsequently removed. Use of a 3-Fr ureteral stent was the only risk factor for the development of stent failure; the failure rate was 20.0% with this stent diameter. Conclusion Ureteral stenting was a useful procedure with a high success rate, even in patients aged <10 years. A 3-Fr ureteral stent was the only risk factor for stent failure; its substantial failure rate should be considered when deciding whether to insert a stent. Also, short-term re-evaluation after ureteral stent insertion is mandatory, especially with 3-Fr ureteral stents.
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A simple method that uses magnetic field induction for the disentanglement of bundled multiwall carbon nanotubes (MWCNTs) that are massively aggregated in a single and intact form was ...investigated. MWCNTs exposed to a 1Tesla (T) field periodically switched on and off were separated into individual MWCNTs using 4,4′-azobis(4-cyanovaleric acid) as a radical initiator with iron oxide nanoparticles. The study results show that, in accordance with the dissipation working principle, MWCNT bundles under 40nN achieved complete disentanglement within a few hours, and these results were theoretically verified by an Opera 3D simulation. We anticipate that single CNTs obtained using our method will have applications in several CNT research areas ranging from electronic devices to biocomputers.
Hot Gas Desulfurizarion for IGCC is a new method to efficiently remove H2S in fuel gas with regenerable sorbents at high temperature and high-pressure conditions. The Korea Institute of Energy ...Research did operation of sulfidation in a desulfurizer and regeneration in a regenerator simultaneously at high pressure and high temperature conditions. The H2S concentration at exit was maintained continuously below 50ppmv at 11,000 ppmv of inlet H2S concentration. The sorbent had little effect on the reducing power in the inlet gas in the range from 11% to 33% of H2. As inlet H2S concentration was increased, H2S concentration in the product gas was also increased linearly. The sorbent was maintained at low sulfur level by the continuous regeneration and the continuous solid circulation at the rate of 1.58× 10−3 kg/s with little mean particle size change.
This study examined the relevance of impact factors using survey data, standardized mortality rates, and medical utilization rates of study subjects in the Namhae and Hadong regions. The study ...subjects were found to have lived in the area for more than 20 years, and in terms of lifestyle, they did not smoke, but the rate of drinking was high and showed little exercise. As a result of analysis through logistic regression analysis, it was found that angina pectoris, myocardial infarction and anemia were affected by exercise status, and allergic rhinitis disease showed significant results depending on the presence of smoking. The standardized mortality rate of men in chronic lower respiratory tract diseases in the Namhae and Hadong regions was higher than in the nation. In the case of allergic rhinitis, both men and women in Namhae were slightly lower than those in Nation, and in Hadong, both men and women were higher than in Nation. KCI Citation Count: 0
