• Journal of Microbiology and Biotechnology
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• v.23 no.4
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• pp.534-538
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• 2013

The effects of lights with different wavelengths on the growth and the yield of extracellular polysaccharides of Nostoc flagelliforme cells were investigated in a liquid cultivation. N. flagelliforme cells were cultured for 16 days in 500 ml conical flasks containing BG11 culture medium under $27{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ of light intensity and $25^{\circ}C$ on a rotary shaker (140 rpm). The chlorophyll a, phycocyanin, allophycocyanin, and phycoerythrin contents in N. flagelliforme cells under the lights of different wavelengths were also measured. It was found that the cell biomass and the yield of polysaccharide changed with different wavelengths of light. The biomass and the yield of extracellular polysaccharides under the red or violet light were higher than those under other light colors. Chlorophyll a, phycocyanin, and allophycocyanin are the main pigments in N. flagelliforme cells. The results showed that N. flagelliforme, like other cyanobacteria, has the ability of adjusting the contents and relative ratio of its pigments with the light quality. As a conclusion, N. flagelliforme cells favor red and violet lights and perform the complementary chromatic adaptation ability to acclimate to the changes of the light quality in the environment.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1205-1208
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• 2010

본 연구는 초등학교 5, 6학년 학생의 인터넷 중독과 학교생활 적응과의 관계를 파악하여 인터넷 사용에 대한 교육적 지도방안과 인터넷 중독 예방프로그램 개발의 기초 자료를 제공하고자 시도되었다. 자료는 2009년 7월 1일에서 7월 24일까지 제주특별자치도에 위치한 초등학교 6개교(동지역 4개교, 읍지역 2개교)를 무작위 추출하여 5, 6학년 학생 총 1195명을 대상으로 조사하였다. 자료 분석은 SPSSWIN(12.0 한글판) 프로그램을 이용하여 카이제곱검정, t-검정, 일원배치 분산분석, 상관분석, 다중회귀분석의 통계적 방법을 이용하였다. 본 연구의 주요 결과는 첫째, 대상자의 인터넷 중독 정도는 고위험군 55명(5.5%), 잠재적위험군 49명 (4.9%), 정상군 900명(89.6%)으로 나타났으며, 둘째, 대상자의 일반적 특성에 따른 인터넷 중독 정도를 분석한 결과 성별, 형제자매 유무, 학교성적에 따라 유의한 차이가 있었다. 셋째, 대상자의 컴퓨터 사용 특성에 따른 인터넷 중독 정도는 최초 인터넷 이용 시기, 인터넷 이용용도, 하루 인터넷 사용 시간, 부모컴퓨터 사용 여부에 따라 유의한 차이가 있었으며, 넷째, 인터넷 중독과 학교생활 적응과의 관계를 분석한 결과 학교생활 부적응인 경우는 '고위험군' 32명(58.2%), '잠재적위험군' 24명(50.0%), '정상군' 257명 (28.7%)으로 고위험군과 잠재적위험군이 정상군보다 학교생활 적응 정도가 낮은 것으로 조사되었다(p<0.01). 다섯째, 인터넷 중독에 유의한 영향을 주는 변수는 학교생활 적응 정도, 성별, 하루 인터넷 사용시간, 인터넷 이용용도, 인터넷 이용 상황, 어머니 직장 유무, 거주 지역, 부모 컴퓨터 사용여부, 최초 인터넷 이용시기이었다. 학교생활 적응 정도가 낮을 때, 남학생, 하루 인터넷 사용시간이 3시간 이상, 인터넷 이용 용도가 '게임', '스트레스가 쌓였을 때' 인터넷을 이용하는 경우, 어머니 직장이 있는 경우, 거주 지역이 동지역, 부모님이 컴퓨터를 사용할 줄 모르는 경우, 최초 인터넷 이용 시기가 취학 전인 경우가 인터넷 중독 점수가 높은 것으로 나타났다. 여섯째, 학교생활 적응에 유의한 영향을 주는 변수는 인터넷 중독 점수, 학교성적, 가정경제수준, 거주지역, 인터넷 이용용도, 학년이었다. 인터넷 중독 점수가 낮을수록, 학교성적이 높을수록, 가정경제수준이 잘 살수록, 거주지역이 동지역, 인터넷 이용용도가 '정보검색, 홈페이지관리/메신저', 5학년인 경우에 학교생활 적응을 더 잘하고 있는 것으로 나타났다. 이상의 결과를 종합해 보면, 학교생활 적응 정도가 낮을수록 인터넷 중독 점수가 높게 나타나고 있고, 인터넷 중독 경향이 높을수록 학교생활 적응 수준이 낮게 나타나고 있음을 알 수 있다. 아동들은 하루중 대부분의 시간을 학교에서 생활하고 있기 때문에 학교생활 적응은 아동들이 건전한 성인으로 성장하는데 중요한 요인이 된다. 또한, 인터넷사용률 증가와 최초 인터넷 이용 연령층이 점점 낮아지고 있음에 따라 인터넷 중독률이 자연스럽게 점점 높아질 것으로 예측되어진다. 따라서, 가정과 학교가 연계하여 아동들의 인터넷 사용에 대한 지속적인 관심과 지도가 필요하며, 인터넷 중독경향이 높은 아동들이 학교생활 적응을 잘할 수 있도록 인터넷 중독 치료 및 예방교육 프로그램 운영이 필요하다 하겠다.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.9
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• pp.1205-1215
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• 2012

This study was conducted to establish genetic criteria for phenotypic characteristics of Hanwoo cattle based on allele frequencies and genetic variance analysis using microsatellite markers. Analysis of the genetic diversity among 399 Hanwoo cattle classified according to nose pigmentation and coat color was carried out using 22 microsatellite markers. The results revealed that the INRA035 locus was associated with the highest $F_{is}$ (0.536). Given that the $F_{is}$ value for the Hanwoo INRA035 population ranged from 0.533 (white) to 1.000 (white spotted), this finding was consistent with the loci being fixed in Hanwoo cattle. Expected heterozygosities of the Hanwoo groups classified by coat colors and degree of nose pigmentation ranged from $0.689{\pm}0.023$ (Holstein) to $0.743{\pm}0.021$ (nose pigmentation level of d). Normal Hanwoo and animals with a mixed white coat showed the closest relationship because the lowest $D_A$ value was observed between these groups. However, a pair-wise differentiation test of $F_{st}$ showed no significant difference among the Hanwoo groups classified by coat color and degree of nose pigmentation (p<0.01). Moreover, results of the neighbor-joining tree based on a $D_A$ genetic distance matrix within 399 Hanwoo individuals and principal component analyses confirmed that different groups of cattle with mixed coat color and nose pigmentation formed other specific groups representing Hanwoo genetic and phenotypic characteristics. The results of this study support a relaxation of policies regulating bull selection or animal registration in an effort to minimize financial loss, and could provide basic information that can be used for establishing criteria to classify Hanwoo phenotypes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1200-1205
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• 2015

Medical foods are enteral nutrition for patients, but they cause maladaptation symptoms like diarrhea. Although the cause of diarrhea remains unknown, some studies have indicated that the cause of diarrhea is fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP). This is a consideration for medical foods since they are easily fermented by intestinal bacterial. In this study, we estimated the FODMAP contents of commercial medical foods and carbohydrate ingredients. We measured the concentrations of FODMAP in 13 types of different medical foods and five types of carbohydrate ingredients by using high performance liquid chromatography with an evaporative light scattering detector (HPLC-ELSD). The limits of detection of FODMAP were fructose, 0.002; lactose, 0.010; raffinose, 0.003; stachyose, 0.032; 1-kestose, 0.005; nystose, 0.012; and 1-fructofuranosylnystose, 0.003 mg/kg. Limits of quantitation of FODMAP were fructose, 0.008; lactose, 0.033; raffinose, 0.009; stachyose, 0.107; 1-kestose, 0.015; nystose, 0.042; and 1-fructofuranosylnystose, 0.011 mg/kg, respectively. Concentration of FODMAP ranged from 0.428~2.968 g/200 mL. Concentrations of carbohydrate ingredients in FODMAP were chicory fiber, 278.423; soy fiber, 27.467; indigestible maltodextrin, 52.384; maltodextrin (DE10~15), 32.973; and maltodextrin (DE15~20), 50.043 g/kg. Contents of carbohydrates were 19.0~41.0 g/200 mL in commercial medical foods. We expected a correlation between contents of carbohydrates and FODMAP, as carbohydrates included FODMAP. However, we detected a low correlation (r=0.55). Since most commercial medical foods have a similar carbohydrate ingredients and nutritional values, the difference between products was determined by FODMAP contents of carbohydrate ingredients. In this study, we analyzed FODMAP contents of commercial medical foods and carbohydrate ingredients. These results are expected to be utilized as basic data for product development and minimizing maladaptation of medical foods.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.83-91
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• 2012

Quorum sensing (QS) is a cell-to-cell communication system, which is used by many bacteria to regulate diverse gene expression in response to changes in population density. Bacteria recognize the differences in cell density by sensing the concentration of signal molecules such as N-acyl-homoserine lactones (AHL) and autoinducer-2 (AI-2). In particular, QS plays a key role in biofilm formation, which is a specific bacterial group behavior. Biofilms are dense aggregates of packed microbial communities that grow on surfaces, and are embedded in a self-produced matrix of extracellular polymeric substances (EPS). QS regulates biofilm dispersal as well as the production of EPS. In some bacteria, biofilm formations are regulated by c-di-GMP-mediated signaling as well as QS, thus the two signaling systems are mutually connected. Biofilms are one of the major virulence factors in pathogenic bacteria. In addition, they cause numerous problems in industrial fields, such as the biofouling of pipes, tanks and membrane bioreactors (MBR). Therefore, the interference of QS, referred to as quorum quenching (QQ) has received a great deal of attention. To inhibit biofilm formation, several strategies to disrupt bacterial QS have been reported, and many enzymes which can degrade or modify the signal molecule AHL have been studied. QQ enzymes, such as AHL-lactonase, AHL-acylase, and oxidoreductases may offer great potential for the effective control of biofilm formation and membrane biofouling in the future. This review describes the process of bacterial QS, biofilm formation, and the close relationship between them. Finally, QQ enzymes and their applications for the reduction of biofouling are also discussed.

• Clinical and Experimental Pediatrics
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• v.50 no.12
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• pp.1200-1205
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• 2007

Purpose : We performed this study to investigate the outcome of surfactant replacement therapy (SRT) in above nearterm neonates who were required mechanical ventilatory care due to meconium aspiration pneumonia (MAP), respiratory distress syndrome (RDS) or other severe pneumonia (PN). Methods : 48 patients, gestational period ${\geq}36weeks$, who were admitted in NICU of Dongsan Medical Center, Keimyung University between July 1999 and June 2004 were enrolled. They were divided into three groups, MAP group (15 cases), RDS group (27 cases) and PN group (6 cases). All patients were received SRT and evaluated several clinical data (gestational age, oxygen index, duration of ventilator care) and outcome (complications and mortality rate) between pre-SRT and post-SRT. The mean dose of surfactant (modified bovine surfactant, Newfacten, Yuhan Co., Seoul, Korea) was 120 mg/kg. Results : Among each groups, mean pre-SRT OI was higher in MAP group ($21{\pm}3.2$) than other groups, mean duration (days) of ventilatory care and oxygen therapy were similar distributions. Compared with pre-SRT values, significant improvements (P<0.05) in mean values for FiO2 and oxygenation index were documented at 12 hours after SRT. Early complications (persistent pulmonary hypertension of newborm, pneumothorax) and survival rate were lower in MAP group. Within RDS group, earlier SRT (given before 12 hours of life) revealed significantly lower early complication rate than later SRT (given after 12 hours of life) (13.3% vs 58.3%, P<0.05) Conclusion : Our study suggested that SRT seems to be an effective therapy in above nearterm neonates with severe pulmonary disease, and earlier SRT tends to reduce complications in RDS group than later therapy.