• 한국균학회소식:학술대회논문집
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• 2015.11a
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• pp.16-16
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• 2015

Ectomycorrhizal (ECM) mushrooms play a major role in plant growth promotion through symbiotic association with roots of forest trees. They also provide an economically important food resource to us and therefore they have been studied for their artificial cultivation for decades in Korea. We have secured bio-resources of ECM mushrooms from Korean forests and performed their physiological studies. To investigate the cultural characteristics, the fungi were cultured under different conditions (medium, temperature, pH of the medium, inorganic nitrogen source). More than 90% of total 160 strains grew on three solid media (potato dextrose agar, PDA; sabouraud dextrose agar, SDA; modified Melin-Norkrans medium, MMN). The rate of mycelial growth on malt extract agar (MEA) was lower than those of three media (PDA, SDA, MMN). None of the Tricholomataceae strains grew on MEA. Many strains of ECM mushrooms were able to grow at the temperature range of $15{\sim}25^{\circ}C$ on PDA, while they showed poor growth at $10^{\circ}C$ or $30^{\circ}C$. In particular, the growth rates of both Gomphaceae and Tricholomataceae were significantly lower at $10^{\circ}C$ than at $30^{\circ}C$. The optimal pH of many strains was pH 5.0 when they cultured in potato dextrose broth (PDB). Fifty-seven percent of tested strains grew well on medium containing ammonium source than nitrate source. Many strains of Tricholomataceae showed a notable growth on ammonium medium than nitrate medium. Twenty-three percent of strains preferred nitrate source than ammonium source for their mycelial growth. The production and activity of two enzymes (cellulase and laccase) by ECM fungi were also assayed on the enzyme screening media containing CMC or ABTS. Each strains exhibited different levels of enzymatic activities as well as enzyme production. The number of laccase-producing strains was less than that of cellulase-producing strains. We found that 77% of tested strains produced both cellulase and laccase, whereas 2% of strains did not produce any enzymes. The morphological characteristics of mycelial colony were also examined on four different solid media. Yellow was a dominant color in mycelial colony and followed by white and brown on all culture media. ECM mushrooms formed mycelial colonies with a single or multiple colors within a culture medium depending on the strains and culture media. The most common shape of mycelial colony was a circular form on all media tested. Other families except for Amanitaceae formed an irregular colony on MMN than PDA. All strains of Tricholomataceae did not form a filamentous colony on all media. The pigmentation of culture media by mycelial colonies was observed in more than 50% of strains tested on both PDA and SDA. The degree of pigmentation on PDA or SDA was higher than MMN and brown color was dominant than yellow color. The production of exudates from mycelial colony was higher on PDA than MMN. Brown exudates were mainly produced by many strains on PDA or SDA, whereas transparent exudates were mainly produced by strains on MMN. We observed the mycelial colonies with a single or multiple textures in just one culture plate. Wrinkled or uneven colony surfaces were remarkably observed in many strains on PDA or SDA, while an even colony surface was observed in many strains on MMN. Sixty percent of Tricholomaceae strains formed wrinkled surface on PDA. However, they did not form any wrinkle on MMN plate. Cottony texture was observed in mycelia colonies of many strains. Velvety texture was often observed in the mycelial colonies on SDA than PDA and accounted for 60% of Suillaceae strains on SDA.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.157-169
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• 2020

The purpose of this study is to investigate the ecological characteristics and vegetation structures of Eurya japonica in Busan. As a result of the TWINSPAN and DCA analysis, 89 plots of 100㎡ each were divided into 3 communities: Quercus serrata-Pinus densiflora-E. japonica community, Pinus thunbergii-E. japonica community, and P. thunbergii-Camellia japonica community. Community I consisted of the Quercus serrata-Pinus densiflora-E. japonica which was mainly located in the high altitude inland. While Q. serrata and P. densiflora competed in the tree layer, the dominant species of the understory layer was E. japonica. Since Carpinus tschonoskii, one of the climax species, was distributed evenly from shrub to tree layers, it was likely that deciduous oak trees or Carpinus tschonoskii would become dominant species in community I. In community I, E. japonica was found in higher altitude than the other evergreen broad-leaved tree and was expected to maintain their tree vigor even if the vegetation structure is converted into the deciduous forest. Community II, the P. thunbergii-E. japonica community, was predicted to maintain its tree vigor unless there were unexpected disturbance factors. Community III, consisting of P. thunbergii-C. japonica and located in Dongbaek Island, was under artificial management. In community III, P. thunbergii was the only species in the tree layer, while C. japonica was predominant in the understory layer. E. japonica and various evergreen broad-leaved tree species were present in the understory layer and shrub layer, which were unmanaged areas. Therefore, it is expected that unless C. japonica is continuously managed, E. japonica is likely to become the dominant species. There were also various evergreen broad-leaved species, such as Machilus thunbergii and Pittosporum tobira, present in the shrub layer. If the temperature continues to rise, the habitat is expected to become evergreen broad-leaved forests in the future as P. thunbergii community declines. The result of Pearson's correlation coefficient analysis of E. japonica and species appearing in 89 plots showed that 9 species were had a statistically significant relationship (p<0.05). Four species, including P. tobira and Q. dentata, had a positive correlation. Five species had a negative correlation, and C. japonica, which had the same ecological position as E. japonica, showed the most negative correlation at -0.384.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.198-209
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• 1986

This study was conducted to find optimum heating temperature and time as milk was heated over a wide range of temperature and time combinations at $70{\sim}100^{\circ}C$ into $5^{\circ}C$ interval for 10, 15 and 20 second. The results obtained were summarized follows: 1. The effects of heat treatment on the bacteria by $75^{\circ}C/20s$, $80^{\circ}C/10s$ and $100^{\circ}C/20s$ were 99.56%, 99.52% and 99.92% respectively. 2. Sterilized rate of milk which was added Bacillus subtilis by $75^{\circ}C/20s$, $80^{\circ}C/10s$ and $100^{\circ}C/20s$ were 99.23%, 99.25% and 99.85% respectively. 3. The pH value fell in accordance with the increasing of heating temperature. 4. Content of protein, fat and lactose was not changed by heat treatment. 5. The content of total nitrogen was not changed. The content of casein nitrogen and non - protein nitrogen increased, but non - casein nitrogen reduced, according to heat trea ted of milk. 6. According to the increasing of heating and time, filter - passing nitrogen reduced. 7. The artificial digestibility was increased when milk was heated from $70^{\circ}C$ to $100^{\circ}C$ into $5^{\circ}C$ interval at 10, 15 and 20 second.

• Journal of Chest Surgery
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• v.29 no.2
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• pp.177-184
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• 1996

Between 1987 and 1994, 21 patients were treated surgically for aortic aneurysm involving the thoracoabdominal aorta. There were 11 males and 10 females, and their age ranged from 20 to 67 years old and mean age was 41.5 years. Many complained of back pain, chest pain or discomfort, and flank pain, but three patients were asymptomatic. 15 patients had chronic dissection (71.4%) and 6 had nondissecting fusiform or saccular aneurysm(28.5%), and of those 15 patients with chronic dissection, 6(28.5%) had atherosclerosis assniated with hypertension, 5 (23.8%) were Martian syndrome, and 2 (9.5%) were associated with pregnancy. The diameter of an aneurysm ranged from 6cm to 12cm, and their extent was classified as type I in 7(33.3%), type II in 8(38.1%), type III in 3(14.3%), and type IV in 3(14.3%) patients based on Crawford classification for TAA . Diseased aorta was replaced with artificial vascular graft in all but one patient. In whom the aortic tear site due to pseudoaneurysm was closed by primary suture. For the spinal cord protection during the operation, we used partial cardiopulmonary bypass (FV-FA or PA-FA bypass) in 12 patients (57.1%), Biopump (LA-FA bypass) in 4(19.0%), total circulartory arrest and CPB in 2 (9.5%), Gott's heparinized shunt in 1(4.7%), and simple aortic cross clamping in 2 (9.5%). The most common complication after the operation was hoarseness due to unilateral vocal cord palsy which onured in 5 patients (23.8%), and the next common complication was wound infection in 4 patients(19.0%), paraplegia in 2 patients (9.5%), chylothorax in 1 patient(4.7%). The hospital mortality rate was 9.5% (2deaths), and there was no late death. Our experience shows that the graft replacement of TAAA had reasonable rate of mortality, low rate of serious complication, and provided good post operative state of the pati nts, and since the thoracoabdominal aortic operation is not a high risky procedure anymore, we recommend a radical operation for the indicated patients.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.321-328
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• 2003

Background: The St. Jude Medical prosthesis is one of the popularly used artificial prosthesis, therefore the National Medical Center reports the long-term clinical results of patients who underwent prosthetic valve replacement with St. Jude medical valve for 18 years. Material and Method: Between January, 1984 and June, 2002, a series of 163 consecutive patients who had Implanted St. Jude prosthesis at the National Medical Center were reviewed. Mean age was 42.9$\pm$15.1 years and male to female ratio was 69:94. The operative procedure comprised of 87 MVR, 30 AVR, 45 DVR, and 1 TVR. The reoperative procedure comprised of 21 MVR, 2 AVR, and 14 DVR. Follow-up rate was 96.9%, and cumulative follow-up was 823.8 patient-years. Result: Early mortality rate was 7.9% (13 patients), late mortality rate was 8.7% (13 patients) and late mortality due to valve related complication was 47% (7 patients). Actual survival rate at 10 and 18 years were 91.7$\pm$2.1% and 91.0$\pm$1.9%. Linearized Incidence was as follows: thromboembolism, 1.09%/ patient-year; anticoagulant related hemorrhage, 0.36%/patient-year; valve thrombosis, 0.24%/patient-year; paravalvular leakage, 0.12%/patient-year; and prosthetic bacterial endocarditis, 0.12%/patient-year linearized incidence of over all valve related complication was 1.94%/patient-year. Freedom from valve related complication at 10 and 18 years were 89.1$\pm$3.3% and 88.4$\pm$3.9%. Freedom from valve related death at 10 and 18 years were 95.1$\pm$1.2% and 95.1$\pm$1.0%. Valve related complication was related the age of patient, especially anticoagulant related hemorrhage was more common in patients over 60 years of age. Valve related complication, death were higher in DVR than AVR or MVR, and valve related death was higher in reoperation. There was no relationship between valve related complication or death and implant valve of size. Conclusion: The long-term clinical results of patients implanted with St. Jude Mechanical prosthesis was quite satisfactory with a low incidence of valve related complication and mortality.

• Food Science and Preservation
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• v.24 no.5
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• pp.707-713
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• 2017

The objective of this study was to select yogurt starter from Korean traditional fermented foods. The 2 strains (KM24, KM32) among 50 strains of isolated lactic acid bacteria selected as starter based on milk clotting ability, antimicrobial activity against various pathogens, tolerance in artificial gastric and bile juice and growth in 10 % skimmed milk. The strains were identified as Lacobacillus plantarum (KM32) and Pediococcus pentosacesus (KM24) by 16S rRNA gene sequencing. Viable cell number of yogurt fermented with mixed strains (KM24 and KM32) was 9.66 log CFU/mL after fermentation for 48 h and maintained $10^9CFU/mL$ during fermentation for 72 h at $37^{\circ}C$. The pH and titratable acidity of mixed cultured yogurt were 4.25% and 0.83% after fermentation for 48 h at $37^{\circ}C$, respectively. The physico-chemical characteristics of mixed cultured yogurt after fermentation for 48 h were $38.45{\mu}g/mL$ (polyphenol content), 48.57% (DPPH radical scavenging activity) and 465.40 cp (viscosity), respectively. The mixed cultured yogurt maintained $10^9CFU/mL$ of lactic acid bacteria during storage 10 days at $4^{\circ}C$. The viable cell number of yogurt prepared with mixed culture(KM32+KM24) maintained higher and than that of control (L. casei) during storage. These results indicated the potential use of selected strains (KM32+KM24) isolated from kimchi as a yogurt starter with strong acid tolerance and probiotics properties.

• Journal of Life Science
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• v.20 no.3
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• pp.381-387
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• 2010

To find offspring of Jeju Black cattle (JBC) produced by embryo transfer (ET) and artificial insemination (AI), a molecular genetic study was carried out in candidate cattle populations collected from cattle farms in Jeju Island, Korea. The genetic marker set was composed of 11 ISAG microsatellite (MS) markers, 11 SAES MS markers selected by our preliminary analysis for population diversity of JBC and two major coat color related genes: MC1R and ASIP. The results showed a combined non-exclusion probability for first parent (NE-P1) that was higher than that recommended by ISAG (above 0.9995), and a combined non-exclusion probability for sib identity of $5.3{\times}10^{-10}$. Parentage analysis showed that the cases identified the candidate's father only (77.0%), mother only (54.0%), and both parents (40.5%) in the candidate offspring population. The ET and AI calves were identified as 14.7% in the in vitro fertilized eggs provided and 32.4% in total population, respectively. However, the result from ISAG marker analysis showed 3 identical allele-combinations in 7 calves, and that from ISAG/SAES MS marker combination also showed 1 identical allele-combination in 2 calves. Data from MS and coat-color gene analyses provided information for complete identification of all animals tested. Because the present JBC population was mostly bred using small nuclear founders through bioengineering techniques such as AI and ET, the genetic diversity levels obtained from MS analysis in the JBC population were relatively lower than those of other cattle populations, including Hanwoo. The results suggested that the more efficient marker combinations, including coat color related genotypes, should be studied and used for constructing a system for identification and molecular breeding of JBC as well.

• Journal of Wetlands Research
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• v.5 no.2
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• pp.15-32
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• 2003

The ecological study on seven wetlands of Haman area in Kyungsangnamdo, Korea, was carried out. In especial, the biological data of the sites were unknown. In this study, water quality including water temperature, pH, DO, COD, T-N, T-P, SS were tested. On the survey of plants and animals, vegetation and flora were investigated and the fauna of insects, fish, and amphibians were studied on each wetland. Water of wetland Oksu was heavily polluted and wetlands Pyungy and Dodulyangy were relatively clean. The water pollution was most severe in winter at all of the wetlands. Plant communities were classified into 9 natural communities and 1 artificial community. On the vegetation, wetland Sugok showed the highest plant taxa, and 41 families, 78 species and 16 varieties were classified. There was remarkable difference in number of plant taxa. The difference may be caused by the variances of wetland sizes, the influence from terrestrial environment. Wetland Sugok showed most rich insect fauna, and 10 orders, 76 families 224 species and 1082 individuals were identified. The species diversity was 2.05 and the species richness was 73.49. Wetland Ddun showed poor insect fauna, and 6 orders, 23 families, 29 species and 81 individuals were identified. Total collected fish were 4 orders, 7 families and 11 species. The fish fauna was most rich in wetlands Oksu and Pyungy, but poor in wetland Unan. Total collected amphibians were 2 orders, 3 families and 4 species.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.51-63
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• 2000

Dynamic traffic assignment(DTA) has been a topic of substantial research during the past decade. While DTA is gradually maturing, many aspects of DTA still need improvement, especially regarding its formulation and solution algerian Recently, with its promise for In(Intelligent Transportation System) and GIS(Geographic Information System) applications, DTA have received increasing attention. This potential also implies higher requirement for DTA modeling, especially regarding its solution efficiency for real-time implementation. But DTA have many mathematical difficulties in searching process due to the complexity of spatial and temporal variables. Although many solution algorithms have been studied, conventional methods cannot iud the solution in case that objective function or constraints is not convex. In this paper, the genetic algorithm to find the solution of DTA is applied and the Merchant-Nemhauser model is used as DTA model because it has a nonconvex constraint set. To handle the nonconvex constraint set the GENOCOP III system which is a kind of the genetic algorithm is used in this study. Results for the sample network have been compared with the results of conventional method.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.484-495
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• 2020

This study is a mixed surfactant (MimicLipid-MSM1000) that forms the same structure as that of the stratum corneum, sucrose distearate, polyglyceryl-2 dioleate, fermented squalane, ergosterol, 10-hydroxystearic acid, mixture consisting of was synthesized. When using 2~5 wt% of this mixed surfactant, it was possible to make an artificial skin mimetic that forms a multi-layer lamellar structure of 5~30 layers. An emulsion was prepared using this mixed surfactant, and a multi-layered lamellar phase was formed and analyzed mechanically. The appearance of this surfactant was a light brown hard wax, the hydrophilic lipophilic balance (HLB) was 12.53, the critical parameter value was 0.987, and the acid value was 0.13. Stability according to pH change was also stable in acidic (3.8), neutral (7.2) and alkaline (10.8). The particle size of the liquid crystal was found to be the most stable maltese cross lamellar crystalline droplet at 5~25mm. The size of the emulsified particles according to the change in the speed of the homo agitator is 2500 rpm (17.9mm±2.6mm), 3500rpm (12.5mm±2.1mm), 4500rpm (6.2mm±1.8mm) particles were formed. Liquid crystal forming particles were observed through a polarization microscope, and the formation structure of the liquid crystal was precisely analyzed with a scanning electron microscope (cryo-SEM). As an application field, it is expected that it will be widely applicable to the development of various prescriptions, such as various skin care cosmetics, makeup care cosmetics, and scalp protection cosmetics, by using a skin-mimicking surfactant.