• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.413-424
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• 2020

Environmental policies and industry practices have recently seen a gradual paradigm shift from reactive management to proactive prevention of environmental impacts. Accordingly, preventive conservation policies are carried out to address the increasing value of protecting soils and soil functions as resources are limited. To propose a direction for future soil erosion research, we analyzed domestic and international research trends of soil erosion, based on journal papers retrieved from the Web of Science databases over the last decade, using VOSviewer for keyword co-occurrence analysis. The results showed that the number of publications on soil erosion per land area in Korea ranked high worldwide. In particular, studies on the soil erosion control were found to account for a more significant proportion than other countries. The active ongoing studies on soil erosion in Korea indicate that the country has recognized the severity of soil erosion resulting from climate, topography, and land use. However, the number of keywords found in the studies on the soil erosion control in Korea was relatively smaller than those found at the international level, indicating the need to diversify and expand the study subjects. In particular, studies on the soil erosion process and the related physical and chemical soil properties are necessary to find the fundamental solutions to soil erosion problems.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7295-7302
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• 2015

Background: Lung cancer has been a major health problem in developed countries for several decades, and has emerged recently as the leading cause of cancer death in many developing countries. The incidence of lung cancer appears to be increasing more rapidly in rural than in urban areas of China. This paper presents the trends of lung cancer incidence and survival derived from a 40-year population-based cancer monitoring program in a rural area, Qidong, China. Materials and Methods: The Qidong cancer registration data of 1972-2011 were used to calculate the crude rate, age-standardized rate by Chinese population (CASR) and by world population (WASR), birth cohort rates, and other descriptive features. Active and passive methods were used to construct the data set, with a deadline of the latest follow-up of April 30, 2012. Results: The total number of lung cancer cases was 15,340, accounting for 16.5% of all sites combined. The crude incidence rate, CASR and WASR of this cancer were 34.1, 15.7 and 25.4 per 100,000, respectively. Males had higher crude rates than females (49.7 vs 19.0). Rapidly increasing trends were found in annual percent change resulting in lung cancer being a number one cancer site after year 2010 in Qidong. Birth cohort analysis showed incidence rates have increased for all age groups over 24 years old. The 5 year observed survival rates were 3.55% in 1973-1977, 3.92 in 1983-1987, 3.69% in 1993-1997, and 6.32% in 2003-2007. Males experienced poorer survival than did females. Conclusions: Lung cancer has become a major cancer-related health problem in this rural area. The rapid increases in incidence likely result from an increased cigarette smoking rate and evolving environmental risk factors. Lung cancer survival, while showing some improvement in prognosis, still remains well below that observed in the developed areas of the world.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.287.1-287.1
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• 2016

Three-dimensional (3-D) semiconductor nanoarchitectures, including nano- and micro- rods, pyramids, and disks, are emerging as one of the most promising elements for future optoelectronic devices. Since these 3-D semiconductor nanoarchitectures have many interesting unconventional properties, including the use of large light-emitting surface area and semipolar/nonpolar nano- or micro-facets, numerous studies reported on novel device applications of these 3-D nanoarchitectures. In particular, 3-D nanoarchitecture devices can have noticeably different current spreading characteristics compared with conventional thin film devices, due to their elaborate 3-D geometry. Utilizing this feature in a highly controlled manner, color-tunable light-emitting diodes (LEDs) were demonstrated by controlling the spatial distribution of current density over the multifaceted GaN LEDs. Meanwhile, for the fabrication of high brightness, single color emitting LEDs or laser diodes, uniform and high density of electrical current must be injected into the entire active layers of the nanoarchitecture devices. Here, we report on a new device structure to inject uniform and high density of electrical current through the 3-D semiconductor nanoarchitecture LEDs using metal core inside microtube LEDs. In this work, we report the fabrications and characteristics of metal-cored coaxial $GaN/In_xGa_{1-x}N$ microtube LEDs. For the fabrication of metal-cored microtube LEDs, $GaN/In_xGa_{1-x}N/ZnO$ coaxial microtube LED arrays grown on an n-GaN/c-Al2O3 substrate were lifted-off from the substrate by wet chemical etching of sacrificial ZnO microtubes and $SiO_2$ layer. The chemically lifted-off layer of LEDs were then stamped upside down on another supporting substrates. Subsequently, Ti/Au and indium tin oxide were deposited on the inner shells of microtubes, forming n-type electrodes of the metal-cored LEDs. The device characteristics were investigated measuring electroluminescence and current-voltage characteristic curves and analyzed by computational modeling of current spreading characteristics.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.6
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• pp.252-256
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• 2015

Nitrogen oxides ($NO_X$) was emitted from flue gas of stationary sources and exhaust gas of mobile sources, can leads to various environments problems. Selective Catalysts Reduction (SCR) is the most effective $NO_X$ removal system. Commercial $V_2O_5-WO_3/TiO_2$ catalysts, usually containing $V_2O_5$ 0.5~3 wt%, $WO_3$ 5~10 wt%, and $V_2O_5$ is active in the reduction of $NO_X$ but also in the desired oxidation of $SO_2$ to $SO_3$. To reduce the amount of vanadium, using graphene matrix supported vanadium to synthesize nanocomposite. Then, we fabricated to 1 inch honeycomb type of SCR catalysts adding graphene-vanadium nanocomposite. The chemical-physical characteristics and the catalytic activity were performed by XRD, XRF, BET and Micro-Reactor (MR). As a result, the De-NOX performance was showed, similar to the commercial catalyst activity as 77.8 % and using nanocomposite catalyst as 77.1 % at $350^{\circ}C$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.13 no.3
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• pp.171-180
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• 2015

This study was performed on the removal of Cs, one of the main high- radioactive nuclides contained in the high-radioactive seawater waste (HSW), by adsorption with IE911 (crystalline silicotitanate type). For the effective removal of Cs and the minimization of secondary solid waste generation, adsorption of Cs by IE911 (hereafter denoted as IE911-Cs) was effective to carry out in the m/V (ratio of absorbent weight to solution volume) ratio of 2.5 g/L, and the adsorption time of 1 hour. In these conditions, Cs and Sr were adsorbed about 99% and less than 5%, respectively. IE911-Cs could be also expressed as a Langmuir isotherm and a pseudo-second order rate equation. The adsorption rate constants (k₂) were decreased with increasing initial Cs concentrations and particle sizes, and increased with increasing ratios of m/V, solution temperatures and agitation speeds. The activation energy of IE911-Cs was about 79.9 kJ/mol. It was suggested that IE911-Cs was dominated by a chemical adsorption having a strong bonding form. From the negative values of Gibbs free energy and enthalpy, it was indicated that the reaction of IE911-Cs was a forward, exothermic and relatively active at lower temperatures. Additionally, the negative entropy values were seen that the adsorbed Cs was evenly distributed on the IE911.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.140-146
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• 2009

Cyclosporin, an immunosuppressant, is a representative group of biologically active secondary metabolites produced by the fungus Tolypocladium inflatum. The amount and ratio of cyclosporin derivatives in the culture broth are an important factors for the production of cyclosporin A and the purification in the industrial process. Therefore, we studied the effect of amino acids and complex organic nitrogen sources using Tolypocladium inflatum mutants on the productivity of cyclosporin A and the ratio of cyclosporin derivatives. Overproducing mutant YHC-004 having seven times higher productivity than mother strain's could be obtained through the artificial mutation by UV irradiation. The concentration and kind of organic nitrogens and amino acids shows the profound effect on the productivity of cyclosporin A and ratio of cyclosporin derivatives. As a result, it was possible to raise the productivity and the ratio of cyclosporin A up to 3,430 mg/L and 93% respectively, but on the other hand the other cyclosporin derivatives decreased less than 2% in the culture broth.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.1
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• pp.1-8
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• 2017

Cu/Mn/Ce catalysts for water gas shift (WGS) reaction were synthesized by urea-nitrate combustion method with the fixed molar ratio of Cu/Mn as 1:4 and 1:1 with the doping concentration of Ce from 0.3 to 0.8 mol%. The prepared catalysts were characterized with SEM, BET, XRD, XPS, $H_2$-TPR, $CO_2$ TPD, $N_2O$ chemisorption analysis. The catalytic activity tests were carried out at a GHSV of $28,000h^{-1}$ and a temperature range of 200 to $400^{\circ}C$. The Cu/Mn(CM) catalysts formed Cu-Mn mixed oxide of spinel structure ($Cu_{1.5}Mn_{1.5}O_4$) and manganese oxides ($MnO_x$). However, when a small amount of Ce was doped, the growth of $Cu_{1.5}Mn_{1.5}O_4$ was inhibited and the degree of Cu dispersion were increased. Also, the doping of Ce on the CM catalyst reduced the reduction temperature and the base site to induce the active site of the catalyst to be exposed on the catalyst surface. From the XPS analysis, it was confirmed that maintaining the oxidation state of Cu appropriately was a main factor in the WGS reaction. Consequently, Ce as support and dopant in the water gas shift reaction catalysts exhibited the enhanced catalytic activities on CM catalysts. We found that proper amount of Ce by preparing catalysts with different Cu/Mn ratios.

• BMB Reports
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• v.40 no.2
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• pp.196-204
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• 2007

Our previous study has shown that sodium selenite can cause apoptosis in acute promyelocytic leukemia-derived NB4 cells in a caspase-dependent manner, but the detailed mechanism is unknown. Here we demonstrate a requirement for extracellular signal-regulated protein kinase (ERK) in mediating sodium selenite -induced apoptosis in NB4 cell. Though no apparent elevation of ERK activity was observed during the apoptosis in NB4 cells caused by 20 μM sodium selenite treatment, PD98059 and U0126, specific chemical inhibitors of the MEK/ERK signaling pathway, were shown to strongly prevent the apoptosis process, while ERK activator TPA enhanced the process. It is also known that p38 MAPK inhibitor SB203580 and JNK inhibitor SP600125 had slight effects on apoptosis. Further study indicated that ERK exerted its proapoptotic effect only at the early stage of apoptosis and played an antiapoptotic role at the later stages. Taken together, our findings suggest that ERK plays an active role in mediating sodium seleniteinduced apoptosis in NB4 cells .

• ALGAE
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• v.28 no.1
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• pp.111-119
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• 2013

Marine microalgae are a promising source of organisms that can be cultured and targeted to isolate the broad spectrum of functional metabolites. In this study, two species of cyanobacteria, Chlorella ovalis Butcher and Nannchloropsis oculata Droop, one species of bacillariophyta, Phaeoductylum tricornutum Bohlin, and one species of Dinophyceae, Amphidinium carterae (Hulburt) were cultured and biomasses used to evaluate the proximate comical compositions. Among the determined proximate chemical compositions of the cultured marine microalgae, the highest content of crude proteins and lipids were exhibited in P. tricornutum and A. carterae, respectively. Solvent-solvent partition chromatography was subjected to fractionate each of the cultured species and separated n-hexane, chloroform, ethyl acetate, and aqueous fractions. Nitric oxide production inhibitory level (%) and cytotoxicity effect on lipo-polysaccharide-induced RAW 264.7 macrophages were performed to determine the anti-inflammatory activity. N. oculata hexane and chloroform fractions showed significantly the strongest anti-inflammatory activity at $6.25{\mu}g\;mL^{-1}$ concentration. The cancer cell growth inhibition (%) was determined on three different cell lines including HL-60 (a human promyelocytic leukemia cell line), A549 (a human lung carcinoma cell line), and B16F10 (a mouse melanoma cell line), respectively. Among the extracts, C. ovalis ethyl acetate and A. carterae chloroform fractions suppressed the growth of HL-60 cells significantly at 25 and $50{\mu}g\;mL^{-1}$ concentrations. Thus, the cultured marine microalgae solvent extracts may have potentiality to isolate pharmacologically active metabolites further using advance chromatographic steps. Hence, the cultured marine microalgae can be described as a good candidate for the future therapeutic uses.

• Journal of Life Science
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• v.26 no.3
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• pp.346-352
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• 2016

Aroma inhalation therapy has traditionally been used not only in alternative medicinal treatment but also in psychotherapy. In the first stage of the study, the in silico molecular binding affinity of the major ingredients of Smart-Wave (SW) on the active site of the odorant-binding protein (OBP) was compared with that of citrate anions. The binding affinity of the chemical mixture formula of the major ingredients of SW on the OBP was relatively higher than that of citrate anions. In addition, nasal inhalation of SW had a positive effect upon changes in brain waves. Eighteen healthy volunteers participated in the experiment. The study consisted of measurements of the brain’s meditation level recordings in the pre- and post-SW inhalation periods as compared with negative (EV) and positive (HB) control groups. After SW inhalation, all the subjects stated that they felt “fresher” and that the SW trial group had significantly changed the brain’s meditation in a positive way. SW inhalation also converted EV-induced unstable brain meditation wave patterns into more stable patterns. Collectively, the results of this empirical study strongly suggest that the SW mixture activates the OBP and controls the mental state by regulating brain waves. The results provide scientific evidence that the SW formula has potential as an effective mental-stress controller.