• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.4
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• pp.881-895
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• 2012

Micro-robots are utilized as useful tools in diagnosis and treatment of various human diseases. At present, lots of countries are developing and making many micro-robots. Government of S. Korea are trying to push ahead with the plan as technology policy, for the same reason. So this study examined about micro-robot technology development and trend of S. Korea, by using the method of SWOT(Strength-Weakness-Opportunity-Threat) analysis. As a result, the future policy for micro-robot of S. Korea is to further spur the development of new micro-robot technology and more improvement of the technology level of micro-robots registered by patent as 'micro-robot of bacterium base for lesion treatment' and 'micro-robot moved by compressive fluid'. Finally, It was already confirmed as high level, technology of 'micro-robot of bacterium base for lesion treatment' and 'micro-robot moved by compressive fluid' invented at S. Korea.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.207-211
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• 2011

하천공사의 매립 및 준설 시 뿐만 아니라 최근에는 호우 시에도 발생하는 고농도 오탁수의 유출 확산으로 인하여 주변 수역의 수산자원 및 자연환경에 심각한 영향을 미치고 있다. 특히 유사는 하천과 호소에 유입되어 탁도를 증가시켜 수자원의 이용가치를 저하시키며, 박테리아나 각종 미생물의 이동 매개체가 되고 있다. 또한 퇴적된 유사는 유량이 증가하면 다시 침식되어 부유상태가 되며 이때에 영양염류나 독성물질이 재용출 되기도 하는 등 하천의 물리 및 토양환경의 장 단기적인 변화를 유발하는 원인이 된다. 결국 유사는 다양한 방식으로 하천과 호소의 생태환경에 큰 변화를 초래한다. 부유토사의 발생 가능한 피해의 범위와 정도는 유역의 부유토사 발생율과 하천, 호소 퇴적물의 성분종류와 입도분포, 그리고 유속에 따라 결정된다. 따라서 탁수의 영향범위를 예측하고, 악영향이 예측될 경우에는 탁도를 저하시킬 수 있는 오탁물질의 저하기법을 적용하여 그 대책을 수립하여야 한다. 현재 정부가 역점을 두고 있는 4대강 살리기 사업 중 하나인 하천 준설 사업 시 발생되는 고농도 오탁수는 주변 수역의 수자원 및 자연환경에 심각한 영향을 미치므로 자연환경의 보존, 해양자원을 보호하기 위하여 오탁물질의 제어가 반드시 필요한 실정이다. 기존의 오탁 저감시설이나 방법의 경우 오탁물질의 확산을 제어하는데 한계가 있고 오탁물질의 종류와 관계없이 일률적으로 시공함으로서 오탁제어 효과가 의문 시 되고 있다. 이러한 문제점을 개선하기 위하여 오탁물질의 확산 범위를 줄이고 침강효율을 높이는 방법을 찾아 오탁확산 제어 효율을 개선할 필요가 있다. 본 연구에서는 오탁물질 제어 시 2차 응집물로 인한 오염이 발생하는 않는 천연광물 제올라이트를 이용한 실내실험을 통하여 고농도 탁수의 탁도 저감효율을 파악하여 고농도 탁수의 탁도 저감에 대한 제올라이트의 적용 가능성을 살펴보았다. 4대강 살리기 사업 중인 OO강 OO공구의 OO보 현장에서 하천 준설 시 발생하는 고농도 탁수를 이온을 첨가한 제올라이트를 이용하여 확산제어에 관한 효과를 검토한 결과 2,000NTU 정도의 고농도로 유하하는 탁수에 대하여 제올라이트 혼합 후 20분이 경과한 시점에 제거효율이 90%이상으로 제올라이트의 탁수저감 효과가 대단히 크다는 것을 알 수 있었다.

• Food Science and Preservation
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• v.7 no.1
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• pp.12-18
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• 2000

As am economical and effective way of antimicrobial film fabrication , antimicrobial agents were coated on the LDPE film with a binder mediu. the fabricated films were then applied tomodified atmosphere packaging of fresh strawberries. A binder of polyamide was selected for the coating medium, based on the stability in water. 1% grapefruit seed extract-coated film showed the antimicrobial activity on the plate media against EScherichia coli, Staphylococcus aureus, bacillus subtilis , Bacillus cereus, Leuconostoc mesenteroides, Micrococcus flavus, Saccharomyces cerevisiae, while one with 10% Coptis chinesis extract inhibited only M. 림편 and one coated with 10% rheum palmatum extract did not inhibit any of 10 strains tested. The packages of fresh strawberries by using antimicrobial agents-coated films created the gas compositions of O2 1.4-5.5% and CO2 5.7-7.9%, and contributed to reduced growth of total aerobic bacteria and yeast/molds on the produced. However, their lower microbial count was not correlated directly with the reduced decay of the fruits.

• Journal of Environmental Science International
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• v.29 no.11
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• pp.1109-1123
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• 2020

In this study, the amount of harmful fungi and bacteria contained in the drainage and culture medium from the paprika hydroponic facility is identified. In addition, by proposing the necessity of effective purification of discharged drainage, this study attempted to confirm the possibility of drainage reuse. Finally, this study provides basic data on the basis for calculating the need for purification facilities in the future, as well as improvements in horticulture facility for sustainable agriculture. As a result of the analysis, a total of 12 types of fungi were detected in paprika medium and 10 types of fungi were detected in the drainage, and their densities were 130 and 68, respectively. Among the fungi detected in the media and drainage of the paprika hydroponic facility, the fungi with the highest detection frequency are Fusarium, Phytophthora, and Pythium. In the case of bacteria, a total of 2 types of bacteria were detected in the paprika facilities, and the density was 28 and 23, respectively. Therefore, in order to reuse the drainage and settle the circulating hydroponic cultivation system, a water treatment process capable of appropriate treatment is required.

• Journal of Life Science
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• v.17 no.6 s.86
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• pp.772-777
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• 2007

A rice OsLeuD gene for small subunit of 3-isopropylmalate isomerase (IPMI) (EC 4.2.1.33) has been isolated. OsLeuD gene is located on 109.3 cM of chromosome 2. OsLeuD gene was expressed abundantly in metabolically active organs including leaves and developing seeds, indicating that OsLeuD gene expression is developmentally regulated. The cDNA of OsLeuD gene was coded for 257 amino acids which showed 58% and 48% homology to small subunits of IPMI in OsLeuD genes of cyanobacteria and green sulfur bacteria, respectively. The molecular character of OsLeuD is closely related to those of photosynthetic bacteria rather than those of eukaryotes including fungi and yeast. This suggests that OsLeuD gene in chromosomal genome of plants may possibly be originated from chloroplast genome.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.10
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• pp.845-854
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• 2009

There has been increased concern regarding the release of antibiotics to different environmental compartments due to the possibility of the development of antibiotic resistant bacteria. However, limited information is available regarding the occurrence, fate, and transport of antibiotics in Korea in both the aqueous phase and in solid phases such as sediment and soil. Therefore, this study was conducted to monitor the concentration of released antibiotics in surface water, sediment, and soil adjacent to a cattle manure composting facility in Korea. Specifically, the following six antibiotics were monitored: tetracycline (TC), chlortetracycline (CTC), oxytetracycline (OTC), sulfamethazine (SMT), sulfamethoxazole (SMX), and sulfathiazole (STZ). To extract and quantify the antibiotics from different environmental compartments, solid phase extraction (SPE) and high performance liquid chromatography mass spectrometry (HPLC/MS) techniques were adopted. The concentration of the six antibiotics ranged from below the detection limit (BDL) to 0.71 ${\mu}g$/L in surface water, from BDL to 27.61 ${\mu}g$/L in sediment, and from 0.12 to 157.33 ${\mu}g$/L in soil. In addition, higher concentrations of antibiotics were observed in surface water and sediment at locations closer to the composting facility indicating that composting is the source of the antibiotics found in the environment. Furthermore, higher concentrations of antibiotics were observed in the solid phase (sediment and soil) than the aqueous phase. These findings indicate that the possibility of antibiotic resistant bacteria is increased because such bacteria are more stable in the solid phase. Overall, longterm monitoring of the aqueous phase and solid phase is necessary to gain a better understanding of the impact of antibiotics from source on the environment in Korea.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.303-317
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• 1994

This study was designed to measure the changes in the titer of tooth root antibodies accompanying root resorption associated with orthodontic tooth movement in dogs to explore a role of the specific immune response in root resorption during orthodontic tooth movement. Five adult mongrel dogs, 2 years of age, were used in the study. Six lower incisors were extracted as sources of homologous antigen in the dogs. Tooth root antigen preparations were made from a 6M Guanidine-HCl-10% EDTA(pH5.0) extract of these root dentins. Root resorption was elicited by intrusion of six maxillary incisors with 200-250gm intrusive force. In 9th week, resorbing six maxillary anterior teeth were extracted. Serum samples were taken from each dog prior to intrusion and weekly for 11 consecutive weeks. Serum autoantibody titers were determined with an enzyme-linked immunosorbent assay. As controls for antibody specificity, sera which were previously incubated with tooth root antigen as well as sera to an unrelated bacterial antigen (Porphyromonas gingivalis 33277) for 3 hours at 25 were measured in all runs. Root resorption was monitored monthly using occlusal radiographs. And then root resorption patterns were observed with a zoom stereo microscope (Model SZH-121, Olympus optical Co. Ltd.). Incisors did not show clear radiographic evidence of significant and progressive root resorption, but periodontal ligament space had widened. But root resorption was observed on the apical regions of the maxillary incisors with a zoom stereo microscope. Teeth showed the shallow depression generally accompanying deep resorption. These demonstrate a slight tendency for an immediate decrease followed by rebound to levels above the pre-treatment baseline. A peak titer of autoantibody to dentin antigen occurred on day 28, then steadily decreased during the 9th week period as the roots resorbed and then rapidly spiked in animals when the resorbing teeth were extracted. When sera is incubated with tooth root antigen, serum activity in the ELISA was almost absent. This is because serum activity in the ELISA could be removed by absorption of the serum with dog dentin antigen. Serum ELISA activity to the unrelated bacterial antigen remained essentially unchanged in all animals throughout the experimental period. When the time course of changes in autoantibody to homologous tooth root antigen prepatration and unrelated bacterial antigen was compared, no significant differences were found(${\alpha}=0.05$). In general, the overall pattern of changes in autoantibody was similar to the two antigens. These findings suggest the possibility that these immunologic changes precede a significant development of root resorption lesions rather than merely reflecting their presence. Therefore, this suggests that the changes of antibody levels may have some predictive value for root resorption.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.1-7
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• 2005

Tidal flats have been regarded to carry out transformation and removal of land-derived organic matter, and this purifying capability of organic matter by tidal flats is one of very important reasons for their conservation. However, integral biogeochemical studies on production and decomposition of organic matter by benthic microbes in tidal flats have been absent in Korea, although the information is indispensable to quantification of the purifying capability. Our major goals in this multidisciplinary research were to understand major biogeochemical processes and rates mediated by diverse groups of microbes dominating material cycles in the tidal flats, and to assess the contribution of benthic microbes to removal of organic matter and nutrients in the tidal flats. Our study sites were Ganghwa and Incheon north-port tidal flats that had been regarded as naturally well reserved and organically polluted, respectively. Our research group measured over 3 years primary production, biomass and community structure of primary producers, abundance and production of bacteria, enzyme activities, distribution of protozoa and protozoan grazing rates, rates of denitrification and sulfate reduction, early sediment diagenesis, primary production and respiration based on oxygen microelectrode. We analyzed major features of each biogeochemical process and their interactions. The results are compiled in the following articles in this special issue: An (2005), Hwang and Cho (2005), Mok et at. (2005), Na and Lee (2005), Yang et at. (2005), and Yoo and Choi (2005).

• Journal of Life Science
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• v.18 no.12
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• pp.1693-1699
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• 2008

Recent studies have suggested that inulin might be utilized as a prebiotics for the promotion of antimicrobial growth, but a major obstacle to the use of inulin has been its low bifidogenic effects, which were initially observed in the ceca of broiler chickens. Inulin has some problems with related to denaturation in air and lowering passage rate from upper digestive tract to caecum. To solve this problems, a newly developed compound derived by microencapsulation, inuloprebiotics, was hypothesized to enrich cecal bifidobacterial populations and reduce the colonization levels of Salmonella in the ceca of broiler chickens. The in vitro growth of intestinal beneficial bacteria including Bifidobacterium longum, Bifidobacterium bifidum, Lactobacillus acidophilus, and Lactobacillus casei grew effectively on the medium containing inulin, whereas the growth of Streptococcus aureus and Clostridium perfringens was not differences among the treatment groups. Broiler chickens consumed chow diets containing 0.5%, 0.7% or 1.0% inuloprebiotics, or a control diet without inuloprebiotics supplementation. The chickens on the inuloprebioticssupplemented diets evidenced significantly higher cecal levels of Bifidobacterium and Lactobacillus species as compared with the chickens on the control diet. The population of cecal E. coli and Salmonella was specifically reduced as the result of treatment with inuloprebiotics. However, we noted no significant differences in Bifidobacterium species, E. coli and Salmonella counts among the inuloprebiotics treatment groups. The inuloprebiotics-supplemented diets induced an increase in the serum IgG concentration. The thymus index was significantly increased in the broiler chickens that consumed diets containing 0.7% or 1.0% inuloprebiotics, with the exception of the chickens consuming the diet supplemented with 0.5% inuloprebiotics. These results indicate that the inuloprebiotic preparations exerted an immune system-promoting effect or selectively enriched the cecal Bifidobacterium species populations in the broiler chickens, and also suggest that inuloprebiotics may prove useful as a stable natural antimicrobial agent.

• Journal of Life Science
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• v.22 no.2
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• pp.259-265
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• 2012

A bacterial strain, CK214, exhibiting high motility on an LB agar (1.5%, w/v) surface was isolated from the environment. The formation of unusual agar shrinking around colonies on agar plates was observed. The strain grew on minimal media containing pure agar as a sole carbon source. The cell-free culture supernatant of CK214 generated a reduced form of sugar in the in vitro reaction with the use of pure agar as a substrate, suggesting the secretion of an agar-degrading enzyme. The CK214 strain showed swarming motility on the solid media containing a wide range of concentrations of agar (0.5, 1.0, 1.5, 2.0% w/v). Various tests, including Gram staining, API analysis, and phylogenetic analysis based on 16S rDNA sequences identified that the CK214 strain was a G(+) rod-shaped bacterium grouped in genus Paenibacillus. Electron microscopic analysis demonstrated that the P. CK214 strain is peritrichously flagellated. Through transposon random mutagenesis, several agar-degrading activity defective mutants (ADMs) were generated. These mutants will be used in the future experimentation for the study of the correlation between agar-degrading activity and motility.