• 한국식물병리학회지
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• 제10권2호
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• pp.144-147
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• 1994

About 450 phytopathogenic fungal cultures were stored in sterile distilled water ar room temperature by the sterile water storage method, which has been known as a simple, convenient, and long-term storage method of microorganisms. After 12 months, viability and pathogenicity of the stored isolates were tested. Among 205 tested, 175 isolates (84.5%) survived. Of these, Rhizoctonia solani, Botrytis cinerea, Pyricularia oryzae, Phytophthora infestans, and Sclerotinia sclerotiorum showed relatively lower survival rate; 92%, 74.1%, 62.5%, 45.8%, and 30%, respectively. Twenty seven isolates belonging to seven important phytopathogenic fungi were tested for pathogenicity, and all isolates tested maintained pathogenicity until at least 12 months after storage.

• 한국균학회지
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• 제26권1호통권84호
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• pp.91-96
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• 1998

국내에서 채집, 분리한 12종 버섯류의 균사를 대상으로 하여 멸균 증류수를 이용한 최적 보존 방법을 탐색하였다. 온도, cryoprotectant의 종류 및 농도 등의 조건을 달리하여 12개월간 보존 후 생존을 및 생장속도를 측정한 결과, 보존 온도는 상온과 $5^{\circ}C$가 최적으로 대상 균주 거의 모두가 생존하여 91.7%의 생존율을 보였다. 균사의 생장속도는 저온인 $-75^{\circ}C$에 보존하였을 때 가장 높았으며, 이 온도에서 보존시 polyethylene glycol를 cryoprotectant로 첨가하였을 때 최대의 생존율이 관찰되었다. 향기갈색깔대기버섯(H. ferrugineum)을 대상으로 하여 계대배양으로 보존한 균주와 $5^{\circ}C$에서 보존한 균주의 세포내 laccase의 활성을 조사한 결과, 효소의 활성양상이 동일하게 나타났다.

• Journal of Microbiology
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• 제34권3호
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• pp.241-247
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• 1996

The stability of the genetically engineered microorganisms and their recombinant plasmids released in natural environments has been regarded as one of the molecular ecological topics. In this study, the recombinant plasmids pCU103 in which the pcbCD genes involved in biodegradation of biphenyl and 4-chlorobiphenyl were cloned in pBluescript SK(+) vector, were examined for their structural and functional stability in different waters at 15 $^{\circ}C$ by the methods of electrophoresis, Southern hybridization, quantification with fluorescent dye, and transformation. The recombinant plamids maintained their stabilities for about 30 days in sterilized distilled water (SDW), 15 days in autoclaved creek water (AW), 25 days in filtered and autoclaved non-sterile creek water (FAW), 4 days in Luria-Bertani (LB) broth, and less than one day in filtered non-sterile creek water (FW). The covalently closed circular (CCC) form of the plasmid was decreased and open circular (OC) form was increased as a function of incubation time, and then linear (L) form was produced to be ultimately degraded out. The degradation rates of the plasmid were proportionally correlated to trophic level of the water, and the biological factor such as DNases was found to be one of the most critical factors affecting structural and functional stability of the plasmid in non-sterile natural water.

• 구강회복응용과학지
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• 제32권4호
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• pp.274-279
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• 2016

목적: 치과 기공용 연마기 휠을 소독하기 위한 클로르헥시딘의 농도에 따른 캔디다균의 감염방지효과에 대해 알아보고자 하였다. 연구 재료 및 방법: 동일한 모형에서 제작된 상악 총의치를 캔디다균에 감염시키고, 서로 다른 농도의 클로르헥시딘 용액에 1시간 보관한 연마 휠과 멸균된 퍼미스와 증류수를 이용하여, 치과기공용 연마기로 연마하였다. 이후 멸균된 상악 총의치를 연이어 연마한 뒤 연마한 부위를 면봉으로 채취하여, 재배양후 칸디다균의 여부를 확인하였다. 결과: 클로르 헥시딘을 적용한 연마휠은 농도에 관계 없이 감염의 전파가 일어나지 않았으나, 증류수만을 사용한 연마휠에서는 감염의 전파가 나타났다. 결론: 의치 연마기 휠의 감염방지를 위해 클로르헥시딘 용액은 효과적이다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.43-43
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• 2017

During grain filling period, rice is affected by many environmental factors; including temperature, water, radiation and soil nutrition condition. In future climate, greater shading and heat tolerance will be required in rice. In this study, the effect of shading and high temperature on spikelet sterility was conducted on fourteen Vietnamese cultivars. Field experiments were studied in 2015 and 2016 to evaluate the response of Vietnamese cultivars under high temperature during grain filling stage. The high temperature and shading were applied by closing two sides of growth chamber and covered by a black cloth (50% reduced solar radiation) under the field condition after the first cultivar heading. The sterility increased significantly under high temperature and shading. The highest percentage sterile spiketlets was observed in 'Jasmine 85' (71.7%) under shading and in 'OM4900' (53.4%) under high temperature in 2015 and 2016, respectively. Among the treatments, the percentage of sterile spekelets in Vietnamese cultivars under shading was highest which was 54.9% and 41.8% in 2015 and 2016, respectively. Yield components reduced significantly in both of shading and high temperature. Corresponding with significantly decrease in yield components, the yield in high temperature and shading decreased strongly in both 2015 and 2016.

• Neonatal Medicine
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• 제25권2호
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• pp.72-77
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• 2018

Purpose: Glucose has been recommended as an analgesic for mild to moderately painful procedures in neonates. The goal of this study was to assess the optimal dextrose concentration for pain control in newborns. Methods: This prospective, randomized, blinded clinical trial included 116 healthy full-term newborns. The neonates were randomly assigned to the following four groups by drawing straws: groups receiving sterile water or a 10%, 20%, or 40% dextrose solution orally. Each group was treated with the assigned solution prior to hepatitis B vaccination. The Neonatal Facial Coding System (NFCS) and the Neonatal Infant Pain Scale (NIPS) scores were evaluated before, immediately after, and 2 minutes after the injection in all neonates. Premature Infant Pain Profile (PIPP) scores were evaluated during the injection. All procedures were video-recorded, and pain scores were assessed by two independent observers who were not involved in the care of the newborns studied. The pain scores were compared among the four groups. Results: The 40% dextrose solution significantly reduced the NFCS (P=0.002) and the PIPP scores (P=0.001) compared with sterile water. No hyperglycemic events were noted in the study subjects 2 hours after the injection. Conclusion: The 40% dextrose solution effectively relieved pain due to intramuscular injection in full-term newborns without causing hyperglycemic events. However, the 10% and 20% dextrose solutions did not affect neonatal pain scores.

• Mycobiology
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• 제33권2호
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• pp.69-76
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• 2005

Conidial development of Cordyceps militaris was observed from germinating ascospores and vegetative hyphae through light and scanning electron microscopy (SEM). Ascospores were discharged from fresh specimens of C. militaris in sterile water as well as Sabouraud Dextrose agar plus Yeast Extract (SDAY) plates. We observed ascospore germination and conidial formation periodically. Under submerged condition in sterile water, most part-spores germinated unidirectionally and conidia were developed directly from the tips of germinating hyphae of part-spores within 36 h after ascospore discharge, showing microcyclic conidiation. First-formed conidia were cylindrical or clavate followed by globose and ellipsoidal ones. Germination of ascospores and conidial development were observed on SDAY agar by SEM. Slimy heads of conidia on variously arranged phialides, from solitary to whorl, developed 5 days after ascospore discharge. Besides, two distinct types of conidia, elongated pyriform or cylindrical and globose, were observed in the same slimy heads by SEM. Conidia were shown to be uninucleate with 4,6-diamidino-2-phenylindole staining. Conidiogenous cells were more slender than vegetative hyphae, having attenuated tips. Microcyclic conidiation, undifferentiated conidiogenous hyphae (phialides), polymorphic conidia and solitary, opposite to whorled type of phialidic arrangement are reported here as the characteristic features of asexual stage of C. militaris, which can be distinguished from other Cordyceps species.

• The Korean Journal of Ecology
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• 제18권1호
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• pp.109-120
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• 1995

As the genetically modified microorganisms (GMMs) and their recombinant plasmid DNAs could be released into natural environments, their stabilities and impacts to indigenous microorganisls have become very importhant research subjects concerning with environmental and ecological aspects. In this study, the genetically modified E. coli CU103 and its recombinant pCU103 plasmid DNA, in which pcbCD genes involving in degradation of biphenyl and 4-chlorobiphenyl were cloned, were studied for their survival and stability in several different waters established under laboratory conditions. E. coli CU103 and its host E. coli XL1-Blue survived longer in sterile distilled water (SDW) and filtered autoclaved river water (FAW) than in filtered river water (FW). A lot of extracellular DNAs were released from E. coli CU103 by lytic action of phages in FW and the released DNAs were degraded by DNase dissolved in the water. Such effects of the factors in FW on stability of the recombinant pCU103 plasmid were also observed in the results of gel electrophoresis, quantitative analysis with bisbenzimide, and transformation assay. Therefore, the recombinant plasmids of pCU103 were found to be readily liberated from the genetically modified E. coli CU103 into waters by normal metabolic processes and lysis of cells. And the plasmid DNAs were quite stable in waters, but their stabilities could be affected by physicoKDICical and biological factors in non-sterile natural waters.

• 한국환경농학회지
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• 제14권1호
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• pp.28-44
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• 1995

밭토양중 myclobutanil의 분해성과 이 농약이 토양미생물상에 미치는 영향을 검토하기 위하여 살균 ${\cdot}$ 비살균토양과 수분함량, 토양 pH, 토양 온도, 약제처리농도, 토양종류 및 실내 ${\cdot}$ 포장토양등의 조건에 따라 myclobutanil을 처리한후 경시적으로 토양을 채취하여 농약잔류량과 토양미생물수를 조사하였는바 그 결과는 다음과 같다. 회귀식에서 구한 분해반감기로 본 myclobutanil의 분해속도는 살균토양에서보다 비살균토양에서, 실내실험에서보다 포장실험에서, 20ppm처리보다 10ppm처리에서, 그리고 미사질양토에서보다 식양토에서 각각 3.9배, 1.6배, 1.4배 그리고 1.2배 정도 빨랐다. 토양 pH의 차이에 따른 myclobutanil의 분해속도는 pH 9에서 가장 빨랐고 pH 5.5에서 가장 느렸으며, 토양온도의 차이에 따른 myclobutanil의 분해속도는 $27^{\circ}C$ > $37^{\circ}C$ > $17^{\circ}C$ 의 순으로 빨랐고, 토양수분함량별 실험에서 myclobutanil의 분해속도는 차이가 없었다. 살균토양에서의 미생물수는 매우 적었으나 비살균토양에서는 많이 발생되었다. 수분함량, pH, 온도, 처리농도 및 토성의 차이에 따른 myclobutanil의 처리구와 무처리구간의 미생물수를 T-검정한 결과 차이가 나지않았다. 포장실험토양에서 사상균 및 총균수는 myclobutanil 처리구가 무처리구보다 많았으나 실내실험토양에서는 차이가 나지 않았다. Myclobutanil 무처리구내에 있어서 pH, 처리농도, 토성 및 실내.포장조건의 차이에 따른 미생물수는 차이가 나지 않았으나, 포장용수량의 60% 수분함량에서는 40% 수분함량에서 보다 세균이 그리고 토양온도 $17^{\circ}C$에서는 $37^{\circ}C$에서보다 사상균이 각각 많이 발생되었다. Myclobutanil 처리구내에 있어서 pH 및 포장.실내조건의 차이에 따른 미생물수는 차이가 없었으나, 세균과 총균수가 포장용수량의 80%수분함량에서는 40%와 60%수분함량에서보다 많았으며, 방선균의 수는 $17^{\circ}C$에서보다 $27^{\circ}C$에서 그리고 미사질양토에서보다 식양토에서 각각 많았다.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.124-128
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• 1998

The procedures currently used for determining microbiological quality of natural mineral water recommend filtration through membrane filters. In this study, we evaluated the effect of vacuum pressure for the accurate detection of bacteria from water samples seeded with Escherichia coli. We observed that the number of E. coli detected increased with increasing vacuum pressure. In order to examine the retention rate of bacteria in the holes of the membranes under the different pressures, the membrane filters were removed after filtration, washed with sterile water by vortexing, and placed on m-Endo agar plates. With all the filters tested, the number of E. coli retained within the filters at negative 600 mmHg was approximately 10 to $20\%$ higher than that obtained with 100 mmHg. These results demonstrate that the vacuum pressure exerted during the filtration procedure may affect the fixation of bacteria into some portions of openings in the membrane filter.