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Search Results: 1 - 10 of 1368 matches for " Myung Chae "
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Heavy Metal Concentrations in Soils and Factors Affecting Metal Uptake by Plants in the Vicinity of a Korean Cu-W Mine
Myung Chae Jung
Sensors , 2008, DOI: 10.3390/s8042413
Abstract: Heavy metal concentrations were measured in soils and plants in and around a copper-tungsten mine in southeast Korea to investigate the influence of past base metal mining on the surface environment. The results of chemical analysis indicate that the heavy metals in soils decreased with distance from the source, controlled mainly by water movement and topography. The metal concentrations measured in plant species generally decreased in the order; spring onions > soybean leaves > perilla leaves ? red pepper > corn grains ? jujube grains, although this pattern varied moderately between different elements. The results agree with other reports that metal concentrations in leaves are usually much higher than those in grain. Factors influencing the bioavailability of metals and their occurrences in crops were found as soil pH, cation exchange capacity, organic matter content, soil texture, and interaction among the target elements. It is concluded that total metal concentrations in soils are the main controls on their contents in plants. Soil pH was also an important factor. A stepwise linear multiple regression analysis was also conducted to identify the dominant factors influencing metal uptake by plants. Metal concentrations in plants were also estimated by computer-aided statistical methods.
Heavy Metal Concentrations in Soils and Factors Affecting Metal Uptake by Plants in the Vicinity of a Korean Cu-W Mine
Myung Chae Jung
Sensors , 2008,
Abstract: Heavy metal concentrations were measured in soils and plants in and around a copper-tungsten mine in southeast Korea to investigate the influence of past base metal mining on the surface environment. The results of chemical analysis indicate that the heavy metals in soils decreased with distance from the source, controlled mainly by water movement and topography. The metal concentrations measured in plant species generally decreased in the order; spring onions > soybean leaves > perilla leaves red pepper > corn grains jujube grains, although this pattern varied moderately between different elements. The results agree with other reports that metal concentrations in leaves are usually much higher than those in grain. Factors influencing the bioavailability of metals and their occurrences in crops were found as soil pH, cation exchange capacity, organic matter content, soil texture, and interaction among the target elements. It is concluded that total metal concentrations in soils are the main controls on their contents in plants. Soil pH was also an important factor. A stepwise linear multiple regression analysis was also conducted to identify the dominant factors influencing metal uptake by plants. Metal concentrations in plants were also estimated by computer-aided statistical methods.
Physical and Metals Impact of Traditional Gold Mining on Soils in Kombo-Laka Area (Meiganga, Cameroon)  [PDF]
Ekengele Nga Léopold, Danala Danga Sabine, Zo’o Zame Philémon, Myung Chae Jung
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.79084
Abstract: Concentrations of metals (As, Cr, Cd, Fe, Ni, Pb, Sb, and Zn) in soil samples from Kombo-Laka were investigated. The area under study is subjected to traditional gold mining and receives various wastes from miners and mining activities. Direct observations on the field displayed the destruction of soils by this activity. An assessment of pollution was performed using an Enrichment Factor (EF) and geoaccumulation index (Igeo). Levels of As, Cr, Cd, Cu, Pb and Sb in soil samples were above average in the Upper Continental Crust (UCC). EF revealed anthropogenic sources for Cd, As and Sb in these soils. Igeo indicates that Kombo-Laka soils are moderately to extremely polluted with As and Sb. There are high to very high positive correlations among the metals suggesting their possible common sources. This study reveals that traditional gold mining activities in the area are harmful to the environment.
Instrumented ligamentotaxis and stabilization of compression and burst fractures of dorsolumbar and mid-lumbar spines
Moon Myung-Sang,Choi Won-Tae,Sun Doo-Hoon,Chae Jong-Woo
Indian Journal of Orthopaedics , 2007,
Abstract: Background : Controversy continues regarding the best treatment for compression and burst fractures. The axial distraction reduction utilizing the technique emplying the long straight rod or curved short rod without derotation to reduce fracture are practised together with short segment posterolateral fusion (PLF). Effects of the early postoperative mobilization without posterolateral fusion on reduction maintenance and fracture consolidation were not evaluated so far. The present prospective study is designed to assess the effectiveness of i) reduction and restoration of sagittal alignment, ii) no posterolateral fusion on the reduced, fractured vertebral body and injured disc, iii) fracture consolidation and iv) the fate of the unfused cephalad and caudal injured motion segments of the fractured vertebra. Materials and Methods : The study includes 15 Denis burst and two Denis type D compression fractures between T 12 and L 3 . The lordotic distraction technique was used for ligamentotaxis utilizing the contoured short rods and pedicle screw fixator. Three vertebrae including the fractured one were fixed. The patient′s after surgery were braced for ten weeks with activity restriction for 2-4 weeks. The patients were evaluated for change in body height, segittal curve, reduction of retropulsion, improvement in neural deficit. The unfused motion segments, residual postoperative pain and bone and metal failure were also evaluated. Results : The pre-operative and postreduction percentile vertebral heights at, zero (immediate post-operative), at three, six and 12 months followup were 62.4, 94.8, 94.6, 94.5 and 94.5%, respectively. The percentages of the intracanal fragment retropulsion at pre operative, and post operative at zero, 3, 6 and 12 months followup were 59.0, 36.2,, 36.0, 32.3, and 13.6% respectively. The pre-operative and postreduction percentile loss of the canal dimension and at zero, three, six and 12 months were 52.1, 45.0, 44.0, 41.0 and 29% respectively suggesting that the under-reduced fragment was being resorbed gradually by a remodeling process. The mean initial kyphosis of 33° became mean 2° immediately after reduction and mean 3° at the final follow-up. The fractured vertebral bodies consolidated in an average period of ten weeks (range 8-14 weeks). The restored disc heights were relatively well maintained throughout the observation period. All paraparetic patients recovered neurologically. There were no postoperative complications. Conclusion : Instrument-aided ligamentotaxis for compression and burst fractures utilizing the short cont
The Natural Anticancer Agent Plumbagin Induces Potent Cytotoxicity in MCF-7 Human Breast Cancer Cells by Inhibiting a PI-5 Kinase for ROS Generation
Ju-Hee Lee, Ji-Hyun Yeon, Hanna Kim, Whijae Roh, Jeiwook Chae, Han-Oh Park, Dong-Myung Kim
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0045023
Abstract: Drug-induced haploinsufficiency (DIH) in yeast has been considered a valuable tool for drug target identification. A plant metabolite, plumbagin, has potent anticancer activity via reactive oxygen species (ROS) generation. However, the detailed molecular targets of plumbagin for ROS generation are not understood. Here, using DIH and heterozygous deletion mutants of the fission yeast Schizosaccharomyces pombe, we identified 1, 4-phopshatidylinositol 5-kinase (PI5K) its3 as a new molecular target of plumbagin for ROS generation. Plumbagin showed potent anti-proliferative activity (GI50; 10 μM) and induced cell elongation and septum formation in wild-type S. pombe. Furthermore, plumbagin dramatically increased the intracellular ROS level, and pretreatment with the ROS scavenger, N-acetyl cysteine (NAC), protected against growth inhibition by plumbagin, suggesting that ROS play a crucial role in the anti-proliferative activity in S. pombe. Interestingly, significant DIH was observed in an its3-deleted heterozygous mutant, in which ROS generation by plumbagin was higher than that in wild-type cells, implying that its3 contributes to ROS generation by plumbagin in this yeast. In MCF7 human breast cancer cells, plumbagin significantly decreased the level of a human ortholog, 1, 4-phopshatidylinositol 5-kinase (PI5K)-1B, of yeast its3, and knockdown of PI5K-1B using siPI5K-1B increased the ROS level and decreased cell viability. Taken together, these results clearly show that PI5K-1B plays a crucial role in ROS generation as a new molecular target of plumbagin. Moreover, drug target screening using DIH in S. pombe deletion mutants is a valuable tool for identifying molecular targets of anticancer agents.
Relationship between cyclooxygenase 8473T>C polymorphism and the risk of lung cancer: a case-control study
Jung Park, Jin Choi, Myung Chae, Won Lee, Sung Cha, Ji-Woong Son, Chang Kim, Sin Kam, Young Kang, Tae Jung, Jae Park
BMC Cancer , 2006, DOI: 10.1186/1471-2407-6-70
Abstract: The COX-2 genotypes were determined using PCR-based primer-introduced restriction analysis in 582 lung cancer patients and in 582 healthy controls that were frequency-matched for age and gender.The distribution of the COX-2 8473T>C genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by the tumor histology, the combined 8473 TC + CC genotype was associated with a significantly decreased risk of adenocarcinoma as compared with the 8473 TT genotype (adjusted OR = 0.64; 95% CI = 0.46–0.90, P = 0.01). On the stratification analysis, the protective effect of the combined 8473 TC + CC genotype against adenocarcinoma was statistically significant in the males, older individuals and ever-smokers (adjusted OR = 0.59; 95% CI = 0.39–0.91, P = 0.02; adjusted OR = 0.55; 95% CI = 0.33–0.93, P = 0.03; and adjusted OR = 0.57; 95% CI = 0.37–0.87, P = 0.01, respectively).These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung.Although cigarette smoking is the major cause of lung cancer, only a fraction of smokers develop lung cancer during their lifetime, and this suggests that genetic factors are of importance in determining an individual's susceptibility to lung cancer [1].Cyclooxygenase (COX, also known as prostanglandin endoperoxide synthase) is the rate-limiting enzyme for the production of prostaglandins (PGs) from free arachidonic acid. Two isoforms of COX have been identified. COX-1 is constitutively expressed in most normal tissues and it is considered to be a housekeeping enzyme that is responsible for various physiologic functions. In contrast, COX-2 is rarely expressed in normal tissues, but it is rapidly induced in response to cytokines, growth factors and tumor promoters [2. 3]. Overexpression of COX-2 has been reported in a variety of human malignancies, including lung cancer [4-6]. Up-regulation
Ferroelectric switching dynamics of topological vortex domains in a hexagonal manganite
Myung-Geun Han,Yimei Zhu,Lijun Wu,Toshihiro Aoki,Vyacheslav Volkov,Xueyun Wang,Seung Chul Chae,Yoon Seok Oh,Sang-Wook Cheong
Physics , 2013,
Abstract: Field-induced switching of ferroelectric domains with a topological vortex configuration is studied by atomic imaging and electrical biasing in an electron microscope, revealing the role of topological defects on the topologically-guided change of domain-wall pairs in a hexagonal manganite.
The Aesthetic Turn in Everyday Life in Korea  [PDF]
Kwang Myung Kim
Open Journal of Philosophy (OJPP) , 2013, DOI: 10.4236/ojpp.2013.33054
Abstract: We are living in the transitional age from the rational, analytical, and scientific to the cultural, sensitive, and aesthetic. The aesthetics of everyday life lies at the center of this age. There is no boundary between art and life in contemporary art. Almost all the contents and objects of everyday life became a work of art in the condition of searching for the aesthetic. Since aesthetic theory was shifted from the artist-centered or a work of art-centered to the audience, spectator or beholder-centered, art and everyday life were more closely related to each other. So aesthetic attention or attitude is not specific to art, but pervasive broadly in everyday life. We can embrace the aesthetic concerns in everything we make and use every day. In the long tradition of Korean art, it can be seen that aesthetic consciousness is steeped in day-to-day life as well as the arts. I want to consider the problems of everydayness, Korean aesthetic consciousness in daily life, and contemplation in the aesthetic consciousness. Korean art was characterized by its “lack of refinement” and “nonchalance”. The characteristics of Korean art as the qualities of “technique without technique”, “Planning without plan”, “asymmetrical symmetry” have dominated the everyday consciousness of Korean people as well as Korean art. The extension of aesthetic emotion through experimentation shows us the change of aesthetic consciousness as a new possibility of interpretation. We stand in an urgent situation of the need for a new theory of art. It will be related to the future of aesthetics. For this reason, I think we have to consider the meaning of the aesthetic turn in everyday life.
Problems and Prospects of Geoaesthetics  [PDF]
Kwang Myung Kim
Open Journal of Philosophy (OJPP) , 2015, DOI: 10.4236/ojpp.2015.51001
Abstract: Geoaesthetics is the project of making aesthetic sense of nature through geological phenomena. The aesthetic appreciation of nature has recently become urgent because of the serious influence of the natural environment on human beings. The author’s geoaesthetical research is categorized into three problems: art in geology or geology in the arts as the close relationship between art and geology, geological cognition of nature and natural cognition in environmental aesthetics, and the geoaesthetical approach through works of art. Geologic forces and processes have become significant materials for aesthetic sensations. Based on the geoaesthetic perspective, the author explores the ultimate purpose of art as a return to natural order. It seems partly to be related to the ontological problem of art. Here we can feel earthly dynamics, universal calmness, and the contemplative atmosphere simultaneously.
Remarks on the relativistic self-dual Maxwell-Chern-Simons-Higgs system
Dongho Chae
Electronic Journal of Differential Equations , 2000,
Abstract: In this short note we announce some recent developements on the topological multi-vortex solutions of the self-dual Maxwell-Chern-Simons Higgs system. We find that all the topological solutions are admissible. We also discover that the convergence of the topological solution to the solutions of the self-dual Chern-Simons equations can be improved to be strong.
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