• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.523-532
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• 2017

A field survey studying intestinal parasites in humans and microbial pathogen contamination at environment was performed in a Laotian rural village to identify potential risks for disease outbreaks. A parasitological investigation was conducted in Ban Lak Sip village, Luang Prabang, Lao PDR involving fecal samples from 305 inhabitants as well as water samples taken from 3 sites of the local stream. Water analysis indicated the presence of several enteric pathogens, i.e., Aeromonas spp., Vibrio spp., E. coli H7, E. coli O157: H7, verocytotoxin-producing E. coli (VTEC), Shigella spp., and enteric adenovirus. The level of microbial pathogens contamination was associated with human activity, with greater levels of contamination found at the downstream site compared to the site at the village and upstream, respectively. Regarding intestinal parasites, the prevalence of helminth and protozoan infections were 68.9% and 27.2%, respectively. Eight helminth taxa were identified in fecal samples, i.e., 2 tapeworm species (Taenia sp. and Hymenolepis diminuta), 1 trematode (Opisthorchis sp.), and 5 nematodes (Ascaris lumbricoides, Trichuris trichiura, Strongyloides stercoralis, trichostrongylids, and hookworms). Six species of intestinal protists were identified, i.e., Blastocystis hominis, Cyclospora spp., Endolimax nana, Entamoeba histolytica/E. dispar, Entamoeba coli, and Giardia lamblia. Questionnaires and interviews were also conducted to determine risk factors of infection. These analyses together with a prevailing infection level suggested that most of villagers were exposed to parasites in a similar degree due to limited socio-economic differences and sharing of similar practices. Limited access to effective public health facilities is also a significant contributing factor.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.6
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• pp.633-641
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• 2015

Waterborne infectious disease is induced by several pathogenic microbes such as bacteria, viruses and protozoans, and the cases caused by viral infection is currently increasing. Water treatment process could reduce the number of virus in the water, but there were many difficulties to completely remove the virus particles from water. Therefore, the membrane separation technology which was reported to effectively remove pollutants from raw water has attracted increasing attention and demand. Since its efficiency has been introduced, demands for evaluation method toward the membrane filtration process are increasing. However, progression of the method development is slow due to the difficulties in cultivation of several waterborne viruses from animal models or cell culture system. To overcome the difficulties, we used adenovirus, one of the commonly isolated pathogenic waterborne viruses which can grow in cell culture system in vitro. The adenovirus used in this study was identified as human adenovirus C strain. The adenovirus was spiked in the raw water and passed through the microfiltration membrane produced by Econity, a Korean membrane company, and then the viral removal rate was evaluated by real-time PCR. In the results, the amount of virus in the filtered water was decreased approximately by 5 log scale. Because coagulant treatment has been known to reduce filtering function of the membrane by inducing fouling, we also investigated whether there was any interference of coagulant. In the results, we confirmed that coagulant treatment did not show significant interference on microfiltration membrane. In this study, we found that waterborne virus can be effectively removed by membrane filtration system. In particular, here we also suggest that real-time PCR method can rapidly, sensitively and quantitatively evaluate the removal rate of virus. These results may provide a standard method to qualifying membrane filtration processes.

• Journal of Chest Surgery
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• v.23 no.4
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• pp.617-621
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• 1990

A heart supplies blood of about 15, 000 liters to each human organ in a day. A normal function of heart valves is necessary to accomplish these enormous work of heart. The disease of heart valve develops to a narrowness of a closure, resulting in an abnormal circulation of blood. In an attempt to eliminate the affliction of heart valves, the operative method to replace with artificial heart valves has developed and saved numerous patients over past 30 years. This replacement operation has been performed since early 1960`s in Korea, but all the artificial heart valves used are imported from abroad with very high costs until recent years. New artificial heart valves have been developed in Korea Advanced Institute of Science and Technology since early 1980`s. The first developed valve was designed with a free-floating pyrolytic carbon disk that is suspended in a titanium cage. The design of the valve was tested in vitro, and in animals in 1987. The results from this study was that the eccentrically placed struts creates a major and minor orifice when the disc opens and stagnation of flow in the area of the minor orifice has led to valve thrombosis. In this work, the design of the valve was changed from a single - leaflet valve to double - leaflet one in order to resolve the problems observed in the first - year tests. Morphological and hemodynamic studies were made for the newly designed valves through the in vitro and in vivo tests. The design and partial materials of the artificial heart valve was improved comparing with first - year`s model. The disc in the valve was modified from single - leaflet to bi - leaflet, and the material of the cage was changed from titanium metal to silicon - alloyed pyrolytic carbon. A test was made for the valve in order to examine its mechanical performance and stability. Morphological and hemodynamic studies were made for the valve that had been implanted in tricuspid position of mongrel dogs. All the test animals were observed just before the deaths. A new artificial heart valve was designed and fabricated in order to resolve the problems observed in the old model. The new valve was verified to have good stability and high resistance to wear through the performance tests. The hemodynamic properties of the valve after implantation were also estimated to be good in animal tests. Therefore, the results suggest that the newly designed valve in this work has a good quality in view of the biocompatibility. However, valve thrombosis on valve leaflets and annulus were found. This morphological findings were in accordance with results of surface polishing status studies, indicating that a technique of fine polishing of the surface is necessary to develop a valve with higher quality and performance.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.3
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• pp.57-64
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• 2016

The purpose of this research is to study, through the Delphi method, using an expert panel of 14 persons, effective workforce plans for CCTV applications. The need for professional manpower for activities related to CCTV has emerged through technological development and increased utilization of the CCTV industry sectors. Efficient workforce improvement for the CCTV sector presented in this study are in regards to student education. This study proposes an appropriate description for curriculum and related promotional information. This study should create an environment for overcoming the lack of student involvement and commitment to the environment and ensure training after qualification status after the training provided, including measures to maintain. In order to prevent employee turnover, CCTV training is necessary to actively review government support measures. This study also proposes providing a proper educational environment and supply of replacement staff members brought on by training courses. In terms of education administration bodies, we propose that education and training in CCTV management provide a variety of benefits including participation in education, adequate publicity through cooperation with relevant institutions, and introduces new educational programs. We propose providing adequate training that meets the needs of consumer, as well as education, course selection and expanded curriculum in accordance with operating options and the costs of training. In addition, senior student-selected personnel are needed to address the shortage of operators starting work-experience or training.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.39-45
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• 2008

Titanium and its alloys are widely used as dental implants materials because of their excellent mechanical properties. However, the alumina and zirconia ceramics are preferred to use as the substitute of Ti implants because there is a problems in esthetics and biocompatibility in Ti implant. The the glass infiltrated alumina ceramics are studied to increase the toughness and biocompatibility. The 45S5 and soda-lime glass powder was mixed with ethanol at ratio of 1:1 and brushed on the surface of alumina. Then it was heat treated in the electric furnace at $1400^{\circ}C$ from 30 min. to 5 hours. The glass powder was controlled from 200 to $350{\mu}m$ using ball milling. After heat treatment, the glass infiltrated specimen was tested in universal testing machine to measure the bending strength. The surface microstructure of each specimen was observed with SEM. The biocompatibility of 45S5 and soda-lime glass coated alumina was investigated using PBS at $36.5^{\circ}C$ incubator. The specimen was immersed in PBS for 3, 5, 7, 10 days. After that, the surface morphology was investigated with SEM. As the results of experiment, the 45S5 bioglass infiltrated alumina show the increase of bending strength according to the increasing of heat treatment time from 30 min. to 5 hours at $1400^{\circ}C$ Finally the 1370N bending strength of alumina increased to 1958N at 5 hours heat treatment, which shows 1.4 times higher. In contrast to this, the soda lime glass infiltrated alumina ceramics shows the convex curve according to heat treatment time. Thus it shows maximum bending strength of 1820N at 1 hour heat treatment of $1400^{\circ}C$ It gives 1.3 times higher. However, the bending strength of soda lime glass infiltrated alumina is decreasing with increasing heat treatment time after 1 hour. The precipitation on the surface of 45S5 glass infiltrated alumina was revealed as a sodium phosphate ($Na_{6}P_{6}O_{24}6H_{2}O$) and the amount of precipitation is increasing with increasing of immersion time in PBS. In contrast to this, there is no precipitation are observed on the surface of soda lime glass infiltrated alumina. This implies that 45S5 glass infiltrated alumina brings more biocompatible when it is implanted in human body.

• Journal of Korean Home Economics Education Association
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• v.24 no.3
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• pp.1-34
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• 2012

The objectives of this study are to introduce a critical perspective of the multicultural education in home economics education, to develop teaching-learning materials and to apply them in classes for the purpose of enhancing students' multicultural competence for a validity test. For these purposes, family life culture sections from six high school technology and home economics textbooks were analyzed based on the contents and elements of multicultural competence. After recomposing the family life culture sections, this study developed 12-session teaching-learning materials with an emphasis on media literacy. Among them, 4-session plans were taught in classrooms for 247 students in the 10th grades. To test the validity of the plans, a questionnaires was given to the students as a pre- and post-test. The data were analyzed with paired t-tests. The results showed significant pre and post differences in all sections of multicultural competence except the section of 'general cultural understanding'. This implied that the developed teaching-learning materials were effective in helping students overcome ethnocentrism and enhance the understanding of cultural differences.

• The Korean Journal of Air & Space Law and Policy
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• no.spc
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• pp.59-86
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• 2007

The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

• 대한공업교육학회지
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• v.38 no.2
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• pp.1-26
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• 2013

This study inquired following research questions by a narrative research method : What was the job of an engineer in mechanical design field? How did he fulfill his job-related learning in his workplace? What were the context and the characteristic of the job-related learning in the workplace? And some implications of the job-related learning on engineering education were discussed. We identified that the research participant's career as a mechanical engineer has developed through three stages. At first, he engaged on conceptual design of a semi-conductor test machine through self-initiated learning from basic to whole system of the machine. At second stage, he leaded a design group for the concrete design of a ball type semi-conductor test machine. In this stage he learned the meaning of cooperation and cooperative learning. At third stage, he initiated to found an entrepreneur company that was specified to design a semi-conductor test machine. He became CEO of the company. He learned the R & D policy making through contacts with global company, visiting exhibition in abroad. Eventually his main task as a mechanical engineer was the problem solving in the process of machine design. He had experienced and learned through his works : project management, independent fulfilling of tasks, functional analysis and reverse engineering, conceptualizing and test, cohesive cooperation, dialogue and discussion, mediation of conflict, human relationship, leadership. The implication of the narrative analysis on engineering education is, proposed, to give the students more chances to experience and to learn such activities.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.638-645
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• 2013

Interferon-tau (IFNT) is thought to be the conceptus protein that signals maternal recognition of pregnancy in ruminants. We and others have observed that OCT4 expression persists in the trophectoderm of ruminants; thus, both CDX2 and OCT4 coexist during the early stages of conceptus development. The aim of this study was to examine the effect of CDX2 and OCT4 on IFNT gene transcription when evaluated with other transcription factors. Human choriocarcinoma JEG-3 cells were cotransfected with an ovine IFNT (-654-bp)-luciferase reporter (-654-IFNT-Luc) construct and several transcription factor expression plasmids. Cotransfection of the reporter construct with Cdx2, Ets2 and Jun increased transcription of -654-IFNT-Luc by about 12-fold compared with transfection of the construct alone. When cells were initially transfected with Oct4 (0 h) followed by transfection with Cdx2, Ets2 and/or Jun 24 h later, the expression of -654-IFNT-Luc was reduced to control levels. OCT4 also inhibited the stimulatory activity of CDX2 alone, but not when CDX2 was combined with JUN and/or ETS2. Thus, when combined with the other transcription factors, OCT4 exhibited little inhibitory activity towards CDX2. An inhibitor of the transcriptional coactivator CREB binding protein (CREBBP), 12S E1A, reduced CDX2/ETS2/JUN stimulated -654-IFNT-Luc expression by about 40%, indicating that the formation of an appropriate transcription factor complex is required for maximum expression. In conclusion, the presence of OCT4 may initially minimize IFNT expression; however, as elongation proceeds, the increasing expression of CDX2 and formation of the transcription complex leads to greatly increased IFNT expression, resulting in pregnancy establishment in ruminants.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5311-5316
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• 2014

Nuclear factor erythroid 2-related factor 2 (Nrf2) has been recognized as a transcription factor that controls mechanisms of cellular defense response by regulation of three classes of genes, including endogenous antioxidants, phase II detoxifying enzymes and transporters. Previous studies have revealed roles of Nrf2 in resistance to chemotherapeutic agents and high level expression of Nrf2 has been found in many types of cancer. At physiological concentrations, luteolin as a flavonoid compound can inhibit Nrf2 and sensitize cancer cells to chemotherapeutic agents. We reported luteolin loaded in phytosomes as an advanced nanoparticle carrier sensitized MDA-MB 231 cells to doxorubicin. In this study, we prepared nano phytosomes of luteolin to enhance the bioavailability of luteolin and improve passive targeting in breast cancer cells. Our results showed that cotreatment of cells with nano particles containing luteolin and doxorubicin resulted in the highest percentage cell death in MDA-MB 231cells (p<0.05). Furthermore, luteolin-loaded nanoparticles reduced Nrf2 gene expression at the mRNA level in cells to a greater extent than luteolin alone (p<0.05). Similarly, expression of downstream genes for Nrf2 including Ho1 and MDR1 were reduced significantly (p<0.05). Inhibition of Nrf-2 expression caused a marked increase in cancer cell death (p<0.05). Taken together, these results suggest that phytosome technology can improve the efficacy of chemotherapy by overcoming resistance and enhancing permeability of cancer cells to chemical agents and may thus be considered as a potential delivery system to improve therapeutic protocols for cancer patients.