• 한국육종학회지
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• 제51권3호
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• pp.222-233
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• 2019

'해품'은 농촌진흥청 국립식량과학원에서 우리나라 중만생종에 편중된 벼 농사의 문제점을 완화하여 수확기 노동력 분산, 수확 후 관리의 유연성 확보, 이모작 재배의 확대를 위해 품질, 수량, 재배안정성이 향상된 중생종 벼 품종을 개발하고자 육성되었다. 벼흰잎마름병 저항성 고품질 '익산493호'(품종명 '진백')를 모본으로 하고 복합내병충성 '익산495호'('다청')와 단간 내 도복 직파적응성 '익산496호'('중모1005')를 교배한 F₁을 부본으로 삼원교배한 F₁을 약배양하여 계통육성과정, 생산력 검정시험 및 지역적응성 검정시험을 거쳐 육성되었다. '해품'은 보통기보비재배에서 평균 출수기 8월 11일로 '남평'에 비해 3일 정도 빠른 중생종이다. '해품'은 간장이 73 cm로 '남평'보다 8 cm 작은 단간 품종으로 도복에 안정적인 특성을 나타내며, '남평'과 비슷한 내수발아성을 갖추고 있어 중생종 품종의 남부평야지 재배 시 수발아 피해를 경감시키는데 도움을 줄 것으로 생각된다. '해품'은 벼흰잎마름병 저항성 유전자 Xa3과 xa5 두 개가 집적되어 있어 병원성이 강한 벼흰잎마름병균 K3a균계까지 저항성이며 줄무늬잎마름병에 강하고 도열병에 중도저항성을 나타내는 복합 내병성 품종이다. '해품'은 중만생종에 비해 수확기가 빠른 중생종임에도 보통기 보비재배에서 '남평'과 비슷한 수량성을 나타냈으며, 이모작 재배시험에 적용 가능한 수량성을 나타냈다. '해품'은 쌀의 외관품위가 좋고 밥맛이 우수하여 최고품질 품종에 선정되는 등 중생종 품종 및 벼흰잎마름병 저항성 품종의 품질 향상에 기여하였다. '해품'은 최고품질에 적정수량성을 확보하고 있으며 내수발아성, 벼흰잎마름병 저항성 등 재배안정성이 향상된 중생종 품종으로 남부평야지 및 벼흰잎마름병 발병상습지 재배에 적합하다(품종보호권 등록번호: 제6068호, 2016. 5. 3.).

• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1478-1487
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• 2019

Ulcerative colitis (UC), a chronic inflammatory bowel disease, substantially impacts patients' health-related quality of life. In this study, an effective strategy for discovering high-efficiency probiotics has been developed. First, in order to survive in the conditions of the stomach and intestine, high bile salt-resistant and strong acid-resistant strains were screened out from the fecal flora of healthy adults. Next, the probiotic candidates were rescreened by examining the induction ability of IL-10 (anti-inflammatory factor) production in dextran sodium sulfate (DSS)-induced colitis mice, and Lactobacillus sakei 07 (L07) was identified and selected as probiotic P. In the end, fourteen bifidobacterium strains isolated from stools of healthy males were examined for their antimicrobial activity. Bifidobacterium bifidum B10 (73.75% inhibition rate) was selected as probiotic B. Moreover, the colonic IL-6 and $TNF-{\alpha}$ expression of the DSS-induced colitis mice treated with L. sakei 07 (L07) - B. bifidum B10 combination (PB) significantly decreased and the IL-10 expression was up-regulated by PB compared to the DSS group. Furthermore, Bacteroidetes and Actinobacteria decreased and Firmicutes increased in the DSS group mice, significantly. More interestingly, the intestinal flora biodiversity of DSS colitis mice was increased by PB. Of those, the level of B. bifidum increased significantly. The Bacteriodetes/Firmicutes (B/F) ratio increased, and the concentration of homocysteine and LPS in plasma was down-regulated by PB in the DSS-induced colitis mice. Upon administration of PB, the intestinal permeability of the the DSS-induced colitis mice was decreased by approximately 2.01-fold. This method is expected to be used in high-throughput screening of the probiotics against colitis. In addition, the L. sakei 07 - B. bifidum B10 combination holds potential in UC remission by immunomodulatory and gut microbiota modulation.

• Journal of Advanced Marine Engineering and Technology
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• 제19권4호
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• pp.51-60
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• 1995

Along with the rapid development of automobile industry in this country the necessity of high quality braking material is ever increased to maintain the comfortness as well as the safety the passengers. Asbestos-based friction materials are banned in the developed countries because of their cancer-inducing effect. This study focuses on the development of non-acbestos friction material with acceptable properties such as wear resistant high temperature endurant and low-noise enducing. We have all the intermediate test results indicating the contribution of each additives. These are qualitatively analyzed. Manufacturing processes such as opening of the kevlar and degasing at elevated temperature is equally important to attain proper level of friction quality.

• 한국주조공학회지
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• 제3권4호
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• pp.248-255
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• 1983

The effect of chromium, aluminium and copper contents on the structures and mechanical properties of cast iron was investigated. 1) Mechanical properties were improved with the formation of ledeburite by chromium addition. The primary carbides dispersed in martensitic matrix contributed to high strength and wear resistance. 2) Small addition of aluminium decreased hardness of the cast iron. 3) The impact values were decreased by the formation of the double carbides but improved by the heat treatment. 4) Small addition of copper up to a certain level increased the hardness. Also impact values were considerably increased.

• Advances in concrete construction
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• 제15권2호
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• pp.75-84
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• 2023

Currently, polymer matrix nanocomposites (PMCs) are a prominent area of research due to their outstanding mechanical, thermal, and durability properties. The increase in recent studies justifies the possibility of using PMCs in structural retrofitting and reconstruction of damaged infrastructure and serving as new structural material. Using nanotechnology, nanocomposite panels in flooring combine concrete and steel, providing a very high level of performance. In sports flooring, high-performance concrete has become a challenge for reducing sports injuries and refinement in rehabilitation. As a composite material, this type of resistant concrete is one of the most durable and complex multi-phase materials. This article uses polyvinyl alcohol polymer (PVC) and multi-walled carbon nanotubes as concrete matrix fillers. Solution methods have been used for dispersing PVC and carbon nanotubes in concrete. The water-cement ratio, carbon nanotube weight ratio, and heat treatment parameters influenced the concrete nanocomposite's tensile and compressive strength. The dispersion of carbon nanotubes in cement paste and the observation of nano-microcracks in concrete was evaluated by scanning electron microscope (SEM).

• 미생물학회지
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• 제46권2호
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• pp.148-151
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• 2010

동물성 식품 유래 장구균의 에리스로마이신 내성 유전자형 및 표현형을 분석하고자 하였다. 경기북부지역의 축산 농가 15곳으로부터 원유 시료 378개를 분양받아 본실험에 사용하였으며 에리스로마이신 내성 장구균 분리에 사용하였다. 총 110균주의 장구균이 분리 되었으며 이중 E. faecalis가 101균주, E. avium이 7균주, E durans가 2균주였다. 에리스로마이신에 대한 내성 비율은 65.45%였으며 $MIC_{50}$은 16 ${\mu}g$/ml, $MIC_{90}$은 64 ${\mu}g$/ml이었다. 분리된 장구균 110균주 모두 erm(B) 유전자를 소유하고 있었으며 75.45%인 83균주가 mef(A)를 소유하고 있음을 확인하였다. 표현형 분석에 따르면 지속성 내성($cMLS_B$)을 나타내는 균주는 95균주(86.36%)였으며 유도내성 ($iMLS_B$)을 보이는 균주는 15균주(13.34%)였다.

• 대한의생명과학회지
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• 제18권3호
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• pp.299-306
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• 2012

Recently, the prevalence of 16S rRNA methylase conferring high-level resistance to aminoglycosides has been increasing in Gram-negative bacilli globally. We determined the prevalence and genotype of these methylase-producing bacteria, and characterized the co-resistance to ${\beta}$-lactam antibiotics and quinolone in Gram-negative clinical isolates collected in 2010 at a hospital in Korea. Among 65 amikacin-resistant isolates screened from 864 Gram-negative bacilli (GNB), 16S rRNA methylase genes were detected from 49 isolates, including Acinetobacter baumannii (43), Klebsiella pneumoniae (2), Proteus mirabilis (2) and Serratia marcescens (1), Empedobacter brevis (1). All of the 16S rRNA methylase genotype was armA and no variant sequences of amplified PCR products for armA were noted. The 16S rRNA methylase producing bacteria showed much higher resistance to aminoglycoside for Enterobacteriaceae and glucose non-fermenting (NF)-GNB and to imipenem for glucose NF-GNB, than the non-producing isolates. All of the 16S rRNA methylase producing Enterobacteriaceae had the extended-spectrum-${\beta}$-lactamase. In addition, two K. pneumoniae concurrently produced both plasmid-mediated AmpC ${\beta}$-lactamase and qnrB gene. All of the amikacin-resistant A. baumannii (43) co-harbored armA 16S rRNA methylase and $bla_{OXA-23}$ carbapenemase. In conclusion, 16S rRNA methylase producing bacteria were very prevalent among GNB in South Korea, and were commonly associated with co-resistance, including carbapenem and quinolone.

• 한국생활과학회지
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• 제19권1호
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• pp.191-201
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• 2010

This study attempted to examine the application of retrograded starch (RS3) isolated from rice flour into Madeleine which is easy to make, supply enough energy and micro nutrients with adequate drinks, and prevent an adult disease. This could be a popular food to anyone regardless of age and gender who avoid rice and become high value-added, processed rice foods. For this, control Madeleine was made from wheat flour and an experimental one was made from 5 or 10% rice RS3 addition as well as wheat flour. Four different types of rice were produced from Premium Ho-Pyong Rice, that is, dry milled rice flour(RFD), soaked for 8 hours and milled, followed by air-dried rice flour(RFW), rice starch(RST), and retrograded rice starch or enzyme-resistant starch(RS3). The results found were as follows: Proximate compositions were decreased with soaking to make RFW, RST and RS3, compared to RFD. RS3 had the highest L, +a and ${\Delta}E$ with the lowest +b, changing it to a dark color, explaining the need for heat control during processing. At $80^{\circ}C$, the swelling power was shown in the order of RST>RFW>RFD>RS3 and the solubility of RS3 was the highest. There were significant differences in viscosities of peak, trough, cold, breakdown and total setback of all rice samples using RVA (p<0.001). Due to the pH of RS3, the Madeleine batter became acidic (p<.01) and expanded, resulting in more air cells and open texture. With an increasing RS3 level in Madeleine, several textural attributes among 'fresh' and 'stored at room temperature' Madeleine samples were significantly different by using Texture Analyzer. While the addition of RS3 in Madeleine did not significantly affect the sensory evaluation, indicating RS3 isolated from rice as a beneficial ingredient for processed rice products.

• 식물병연구
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• 제16권3호
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• pp.290-293
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• 2010

국내에서 Clavibacter michiganensis subsp. michiganensis에 의한 궤양병은 토마토 농가에 심각한 피해를 주고 있다. 이에 병 발생의 감소와 방제를 위해서는 저항성 품종이 최선의 해결책으로 제시되고 있다. 따라서 국내에서 시판되고 있는 완숙토마토 39품종, 방울토마토 20품종, 대목토마토 13품종에 대한 궤양병 저항성 품종을 선별하기 위해 저항성 검정을 실시하였다. 시판되는 72품종 중 선명, 스위트, 다다끼, 아기꼬, 매치, 마그네트, 프렌즈, 그린파워, 품종이 궤양병에 대해 저항성을 나타내었다.

• Applied Biological Chemistry
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• 제37권4호
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• pp.248-254
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• 1994

Bromoxynil은 쌍떡잎 특이적 제초제로써 폭 넓게 이용되고 있으며 반감기가 매우 짧다. Bromoxynil을 3,5-dibromo-4-hydroxybenzoic acid로 분해하는 nitrilase를 암호화한 bxn 유전자를 식물 벡터인 pGA482에 도입하고 Agrobacterium과의 동시배양을 통해 담배와 상추에 형질전환하였다. Kanamycin을 이용해 형질전환 식물체를 선별하고 완전한 식물체로 분화시켰다. Northern hybridization을 통해 bxn 유전자의 발현정도를 검정하고 liaf-disc와 pot assay를 통해 형질전환 식물체가 고농도의 bromoxynil에 저항성을 보임을 확인하였다.