140 research outputs found

    Photocatalytic Oxidation of Trichloroethylene in Water Using a Porous Ball of Nano-ZnO and Nanoclay Composite

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    The presence of nondegradable organic compounds and xenobiotic chemicals in water is a great concern for the general public because of their polar properties and toxicity. For instance, trichloroethylene (TCE) is a widely used solvent in the chemical industry, and it is also a contaminant of soil, surface water, and groundwater. Recent studies on new treatment technologies have shown that photocatalyst-based advanced oxidation processes are appropriate for removing these polar and toxic compounds from water. The objective of this study was to remove TCE from water using novel nano-ZnO-laponite porous balls prepared from photocatalyst ZnO with nanoscale laponite. These nano-ZnO-laponite porous balls have a porosity of approximately 20%. A lower initial concentration of TCE resulted in high removal efficiency. Moreover, the removal efficiency increased with increasing pH in the photocatalytic degradation experiments employing UVC light with nano-ZnO-laponite. The optimal dosage of nano-ZnO-laponite was 30 g and the use of UVC light resulted in a higher removal efficiency than that achieved with UVA light. In addition, the removal efficiency of TCE significantly increased with increasing light intensity. We think that TCE’s removal in water by using porous ball of nano-ZnO and nanoclay composite is a result of degradation from hydroxide by photons of nano-ZnO and physical absorption in nanoclay

    Occupational Factors Associated with Changes in the Body Mass Index of Korean Male Manual Workers

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    OBJECTIVES: This study was carried out to analyze and compare the occupational factors that could influence changes in body mass index (BMI) in male manual workers stratified into short-term and long-term work experience groups. METHODS: The subjects were 299 male manual workers (sampled systematically) from 27 workplaces, who had undergone travelling medical examinations at a university hospital between March 28 and May 10, 2013, and had also undergone medical examinations at the same hospital in 2012. Their general and occupational characteristics were investigated through a structured, self-administered questionnaire. The BMI at each point in time was calculated based on the anthropometric results of the medical examinations. Multiple regression analyses were conducted on outcomes of the BMI change and predictors composed of the general and occupational characteristics, with the subjects stratified into groups with 5 years or less (short-term) versus more than 5 years (long-term) of work experience at the present post. RESULTS: In the short-term work experience group, the BMI increases of 3-shift workers and groups reporting disagreement with feeling “insufficient job control” and “lack of reward” at work, two of the subscales of job stress, were significantly higher than those of daytime workers and high-stress groups, respectively. In the long-term work experience group, However, although the BMI increase for 3-shift workers was also significantly higher than that of daytime workers, none of the job stress factors were significantly associated with a BMI increase, whereas the social factors of education and marital status were significant, and some lifestyle factors (such as smoking and regular exercise) were also significant. CONCLUSION: This study showed that, except for 3-shift work, the factors associated with BMI increase could differ depending on the length of job experience. Consequently, different strategies may be needed for workers with short-term versus long-term job experience when designing interventions for preventing their obesity

    In-stent restenosis-prone coronary plaque composition: A retrospective virtual histology-intravascular ultrasound study

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      Background: The mechanism of in-stent restenosis (ISR) is multifactorial, which includes biological, mechanical and technical factors. This study hypothesized that increased inflammatory reaction, which is known to be an important atherosclerotic process, at a culprit lesion may lead to higher restenosis rates. Methods: The study population consisted of 241 patients who had undergone percutaneous coronary intervention with virtual histology-intravascular ultrasound (VH-IVUS) and a 9-month follow-up coronary angiography. Compared herein is the coronary plaque composition between patients with ISR and those without ISR. Results: Patients with ISR (n = 27) were likely to be older (66.2 ± 9.5 years vs. 58.7 ± 11.7 years, p = 0.002) and have higher levels of high-sensitivity C-reactive protein (hs-CRP, 1.60 ± 3.59 mg/dL vs. 0.31 ± 0.76 mg/dL, p < 0.001) than those without ISR (n = 214). VH-IVUS examination showed that percent necrotic core volume (14.3 ± 8.7% vs. 19.5 ± 9.1%, p = 0.005) was higher in those without ISR than those with ISR. Multivariate analysis revealed that hs-CRP (odds ratio [OR] 3.334, 95% con­fidence interval [CI] 1.158–9.596, p = 0.026) and age (OR 3.557, 95% CI 1.242–10.192, p = 0.018) were associated with ISR. Conclusions: This study suggests that ISR is not associated with baseline coronary plaque composition but is associated with old age and increased expression of the inflammatory marker of hs-CRP. (Cardiol J 2018; 25, 1: 7–13

    Determination of Fire Blight Susceptibility on Wild Rosaceae Plants in Korea by Artificial Inoculation

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    The fire blight caused by Erwinia amylovora (Ea) is a devastating disease of Rosaceae plants, including commercially important apple and pear trees. Since the first report in Korea in May 2015, it has been spreading to neighboring regions gradually. Host plants can be infected by pollinators like bees, rainfall accompanied by wind, and cultural practices such as pruning. Many studies have revealed that wild Rosaceae plants such as Cotoneaster spp., Crataegus spp., Pyracantha spp., Prunus spp., and Sorbus spp. can be reservoirs of Ea in nature. However, wild Rosaceae plants in Korea have not been examined yet whether they are susceptible to fire blight. Therefore, the susceptibility to fire blight was examined with 25 species in 10 genera of wild Rosaceae plants, which were collected during 2020–2022, by artificial inoculation. Bacterial suspension (108 cfu/ml) of Ea type strain TS3128 was inoculated artificially in flowers, leaves, stems, and fruits of each plant species, and development of disease symptoms were monitored. Moreover, the presence of Ea bacteria from inoculated samples were checked by conventional polymerase chain reaction. Total 14 species of wild Rosaceae plants showed disease symptoms of fire blight, and Ea bacteria were detected inside of inoculated plant parts. These results suggest that wild Rosaceae plants growing nearby commercial apple and pear orchards in Korea can be Ea reservoirs, and thus they should be monitored regularly to minimize the damage by Ea infection and spreading

    Outdoor-Useable, Wireless/Battery-Free Patch-Type Tissue Oximeter with Radiative Cooling

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    For wearable electronics/optoelectronics, thermal management should be provided for accurate signal acquisition as well as thermal comfort. However, outdoor solar energy gain has restricted the efficiency of some wearable devices like oximeters. Herein, wireless/battery-free and thermally regulated patch-type tissue oximeter (PTO) with radiative cooling structures are presented, which can measure tissue oxygenation under sunlight in reliable manner and will benefit athlete training. To maximize the radiative cooling performance, a nano/microvoids polymer (NMVP) is introduced by combining two perforated polymers to both reduce sunlight absorption and maximize thermal radiation. The optimized NMVP exhibits sub-ambient cooling of 6 °C in daytime under various conditions such as scattered/overcast clouds, high humidity, and clear weather. The NMVP-integrated PTO enables maintaining temperature within ≈1 °C on the skin under sunlight relative to indoor measurement, whereas the normally used, black encapsulated PTO shows over 40 °C owing to solar absorption. The heated PTO exhibits an inaccurate tissue oxygen saturation (StO2) value of ≈67% compared with StO2 in a normal state (i.e., ≈80%). However, the thermally protected PTO presents reliable StO2 of ≈80%. This successful demonstration provides a feasible strategy of thermal management in wearable devices for outdoor applications. © 2021 The Authors. Advanced Science published by Wiley-VCH GmbH1

    E2-25K/Hip-2 regulates caspase-12 in ER stress–mediated AÎČ neurotoxicity

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    Amyloid-ÎČ (AÎČ) neurotoxicity is believed to contribute to the pathogenesis of Alzheimer's disease (AD). Previously we found that E2-25K/Hip-2, an E2 ubiquitin-conjugating enzyme, mediates AÎČ neurotoxicity. Here, we report that E2-25K/Hip-2 modulates caspase-12 activity via the ubiquitin/proteasome system. Levels of endoplasmic reticulum (ER)–resident caspase-12 are strongly up-regulated in the brains of AD model mice, where the enzyme colocalizes with E2-25K/Hip-2. AÎČ increases expression of E2-25K/Hip-2, which then stabilizes caspase-12 protein by inhibiting proteasome activity. This increase in E2-25K/Hip-2 also induces proteolytic activation of caspase-12 through its ability to induce calpainlike activity. Knockdown of E2-25K/Hip-2 expression suppresses neuronal cell death triggered by ER stress, and thus caspase-12 is required for the E2-25K/Hip-2–mediated cell death. Finally, we find that E2-25K/Hip-2–deficient cortical neurons are resistant to AÎČ toxicity and to the induction of ER stress and caspase-12 expression by AÎČ. E2-25K/Hip-2 is thus an essential upstream regulator of the expression and activation of caspase-12 in ER stress–mediated AÎČ neurotoxicity
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