With its increasing value as a means of public transportation, the health effects of the air in subway stations have attracted public concern. In the current study, we investigated the pulmonary toxicity of dust collected from an air purifier installed on the platform of the busiest subway station in Seoul. We found that the dust contained various elements which are attributable to the facilities and equipment used to operate the subway system.
View Article and Find Full Text PDFChronic respiratory disease is among the most common non-communicable diseases, and particulate materials (PM) are a major risk factor. Meanwhile, evidence of the relationship between the physicochemical characteristics of PM and pulmonary toxicity mechanism is still limited. Here, we collected particles (CPM) from the air of a port city adjacent to a cement factory, and we found that the CPM contained various elements, including heavy metals (such as arsenic, thallium, barium, and zirconium) which are predicted to have originated from a cement plant adjacent to the sampling site.
View Article and Find Full Text PDFConsidering the hazardous effects of particulate matter (PM) exposure on students and teachers and the high PM concentration issue in South Korea, air purifiers have recently been installed in most classrooms to improve air quality. However, some on-site challenges, such as operational costs and noise, have been issues with the continuous operation of air purifiers. Therefore, a guideline is needed to dynamically predict the indoor PM concentration based on the changes in outdoor PM concentration and activate the air purifiers only when necessary.
View Article and Find Full Text PDFThe Korean government recommends intermittent operation of air purifiers (APs) as a measure to maintain indoor particulate matter (PM) concentrations below the mandatory standards and reduce exposure to indr PM (PM with a diameter smaller than ). However, there is no guideline to inform occupants of when and how long APs should be operated to comply with the standards. In this study, we developed a dynamic mass-balance model to predict indoor PM concentrations in an office considering penetration of outdoor particles, change in number of occupants, and operational status of the AP.
View Article and Find Full Text PDFThis study was conducted to investigate the effect of different fattening periods on the growth performance, carcass characteristics, and economic traits of Holstein steers. Sixty Holstein steers (8.0 ± 0.
View Article and Find Full Text PDFNanomaterials (Basel)
September 2021
The incorporation of metal oxide nanoparticles (NPs) in fiber filters is an effective approach to enhance the specific surface area and surface roughness of the fiber, hence improving their efficiency for fine dust capture and other gas treatment or biological applications. Nevertheless, uneven distribution of NPs limits their practical applications. In this study, a commercial silane coupling agent (3-methacryloxypropyltrimethoxysilane) was used to improve the dispersion of zinc oxide (ZnO) NPs in thin polyacrylonitrile fibers.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
August 2021
We investigated the influence of a copper loading strategy over a honeycomb structure on the catalytic performance during the decomposition of a hydroxylammonium nitrate (HAN) aqueous solution. Copper was supported on the honeycomb surface by means of a metal coating method (MC), i.e.
View Article and Find Full Text PDFTo evaluate the level of fine particulate matters in elementary schools located in a high traffic area of Seoul and verify the emission source, a field study on the classrooms was conducted under the uncontrolled condition. The indoor PM was lower than that of the outdoors as indicated by an I/O ratio of 0.52-0.
View Article and Find Full Text PDFDecomposition of two typical volatile organic compounds (VOCs): toluene and methyl ethyl ketone (MEK), was investigated by introducing the complete energy yield (i.e. amount of VOCs totally converted to CO and CO for every 1 kWh of electrical usage) and specific energy density (SED) for the non-thermal plasma technology.
View Article and Find Full Text PDFIn this study, we aimed to identify a toxic mechanism and the potential health effects of ambient dusts in an underground subway station. At 24 h exposure to human bronchial epithelial (BEAS-2B) cells (0, 2.5, 10, and 40 μg/mL), dusts located within autophagosome-like vacuoles, whereas a series of autophagic processes appeared to be blocked.
View Article and Find Full Text PDFExposure to particulate matter (PM) in school environments has been associated with respiratory illnesses among children. Although using air cleaners was reported to reduce PM exposure and improve residents' health in homes, their effects in classrooms are not well understood. We examined how the use of air cleaners in classrooms and school/classroom characteristics affect the levels of indoor PM.
View Article and Find Full Text PDFThe CO adsorption selectivity of plain activated carbon nanofibers (ANF) is generally low. For enhancement, nitrogen functionalities favorable for CO adsorption are usually tethered to the ANF. In the current study, we adopted chemical impregnation using 0.
View Article and Find Full Text PDFBackground: Massive intraluminal bleeding requires urgent intervention and management. However, the source of bleeding on the small intestine is difficult to determine. Intestinal tumor with intussusception is a rare and normally not an urgent condition.
View Article and Find Full Text PDFJ Nanosci Nanotechnol
December 2019
The aim of this study is to elucidate the influence of an iridium loading strategy over hexaaluminate on the catalytic performance during the decomposition of liquid monopropellants based on ammonium dinitramide (ADN). Powder-type and pellet-type Ir/hexaaluminate catalysts were prepared and their chemico-physical properties were characterized by N₂ adsorption, XRD, XRF, and SEM. There were considerable differences in the Ir amounts present on the surface according to the impregnation method employed.
View Article and Find Full Text PDFOrdered mesoporous Cu-Mn binary metal oxide (meso-CuMnOx) catalysts were successfully synthesized by a hard-templating method from a mesoporous silica template with a cubic Ia3d mesostructure (KIT-6) or hydrophobic KIT-6, exhibiting a well-developed crystalline framework, a regular pore size distribution and a high surface area. The copper and manganese elements in the mesoporous Cu-Mn binary metal oxides (meso-CuMnOx-N and meso-CuMnOx-HP), obtained from the KIT-6 and hydrophobic KIT-6, respectively, were homogeneously dispersed in the whole particles. The activities of meso-CuMnOx catalysts for the decomposition of a liquid monopropellant containing an energetic ionic liquid, ammonium dinitramide, were much higher than that over a CuMnOx catalyst prepared by a conventional precipitation method.
View Article and Find Full Text PDFMesoporous CuCe-based ternary metal oxides were synthesized using KIT-6 as a hard template through a nano-casting method. The mesoporous CuCe-based metal oxides were applied to the catalytic decomposition of the ammonium dinitramide-based liquid monopropellant. The decomposition onset temperature over the meso-CuCe ternary metal oxides was much lower than that over the CuCeOx catalyst prepared by conventional precipitation method.
View Article and Find Full Text PDFJ Pathol Transl Med
March 2016
Background: Aquaporins are water channel proteins that play a major role in the movement of water in various human tissues. Recently, it has been found that aquaporins have influence in the carcinogenesis of human malignancies. We analyzed the prognostic impact of aquaporin 5 (AQP5) in non-small lung cancer (NSCLC).
View Article and Find Full Text PDFNeuroendocrine carcinoma as a somatic-type malignancy (STM) arising in an extragonadal teratoma is extremely rare. The effect of chemotherapy has been poorly evaluated in such cases contrary to teratomas with other STMs. We herein demonstrate that systemic chemotherapy may be beneficial in a case of neuroendocrine carcinoma arising in a mediastinal teratoma with pulmonary metastasis.
View Article and Find Full Text PDFAngiogenesis is essential for invasive tumor growth and metastasis. Bevacizumab has been widely used for the treatment of non-small cell lung cancer (NSCLC). Various studies clearly demonstrate the relevance of Id-1 and VEGF in angiogenesis.
View Article and Find Full Text PDFJ Air Waste Manag Assoc
November 2012
A pleated filter bag is often used to treat exhaust gas in many industrial applications, due to its fairly high dust collection efficiency and relatively low pressure drop. This work deals with the optimum pleating geometries of a pleated filter made with a newly developed PTFE/glass composite filter. It was found that pleating geometries, including pleat height and pleat pitch, directly affect the cleaning efficiency The design index, alpha, which stands for the ratio of pleat height to pleat pitch, is 1.
View Article and Find Full Text PDFJ Air Waste Manag Assoc
August 2012
Capturing of odorous compounds such as toluene vapor by a particulate-activated carbon adsorbent was investigated in a gas-solid cyclone, which is one type of mobile beds. The test cyclone was early modified with the post cyclone (PoC) and a spiral flow guide to the vortex finder. The proposed process may contribute to the reduction of gases and dust from industrial exhausts, especially when dealing with a low concentration of odorous elements and a large volume ofdust flow.
View Article and Find Full Text PDFThe high costs of ceramic and Teflon filter media for hot gas cleaning has limited their industrial applications. This paper presents a foam coating technology that can be used to produce an inexpensive and highly efficient filter for industrial applications. A new apparatus was designed and built that coats porous glass mats with liquid-phase polytetrafluoroethylene (PTFE).
View Article and Find Full Text PDFA bed-type filter composed of thin metal alloy fiber was closely examined with dust capturing in cold and hot runs. The investigation of an individual mechanism across the filter bed indicated that the aerated dust could be initially collected by depth filtration, and after a while, surface filtration dominated the overall dust collection. The present metal fiber bed was comparable to the conventional ceramic filters because of its good collection efficiency with low pressure drop.
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