• 한국재료학회지
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• 제29권12호
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• pp.735-740
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• 2019

The purpose of this study is to fabricate an ophthalmic lens by copolymerizing two types of carbon nanotubes and hydrophilic hydrogel lens materials, and to investigate its application as an ophthalmic lens material by analyzing its physical properties and antimicrobial effect. For polymerization, HEMA (2-hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate), a crosslinking agent, and AIBN (azobisisobutyronitrile), an initiator, are used as a basic combination, and a single-walled carbon nanotube and a single-walled, carboxylic-acid-functionalized carbon nanotube are used as additives. To analyze the physical properties, the water content, refractive index, breaking strength, and antimicrobial effect of the fabricated lenses are measured. The fabricated lenses satisfies all the basic properties of the basic hydrogel ophthalmic lens. The water content increases with increasing amount of additive and decreases with addition of 0.2 % ratio of nanoparticles. The refractive index is inversely proportional to the water content result. As a result of the antimicrobial test of the fabricated lens, the addition of carbon nanotubes shows an excellent antimicrobial effect. Therefore, it is considered that the fabricated lens can be applied as a functional material for basic ophthalmic hydrogel lenses.

• 한국염색가공학회지
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• 제12권1호
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• pp.61-67
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• 2000

This study was carried out to develope antimicrobial artificial suede by coating with water soluble polyurethane resin and the copolymer of N,N'-dialkyl-N,N'-dialkyl ammonium chloride (DADAAC) and acrylamide as a antimicrobial additve. The copolymer of DADAAC and acrylamide was synthesized by free radical initiation and intra-intermolecular propagation, and the prepared copolymers had sufficient compatibility with water soluble polyurethane resin. The MIC values of the prepared copolymers and antimicrobial characteristics of the artificial suede coated by polyurethane were evaluated. With the increase in the proportion of DADAAC, which is antimicrobially active part in the DADAAC/acrylamide copolymers, the MIC value becomes lower. The MIC value of DADAAC-AA (1 : 1) copolymer is below 30 ppm against S. aureus, and below 90 ppm against K pneumoniae. The artificial suede coated by water soluble polyurethane resin with 1.0% owl concentration of DADAAC/acrylamide copolymer has good antimicrobial fastness as to show colony reduction of above 90% and 80% against S. aureus and K. pneumoniae respectively in the shake flask test after 10 times of washing, and above 95% and 85% after 10 times of dry-cleaning. The elastic recovery of coated suede fabric is not affected up to 1.0% owf concentration of DADAAC-AA copolymer in the polyurethane coating.

• Fisheries and Aquatic Sciences
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• 제6권1호
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• pp.27-33
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• 2003

A lactic acid bacterium showing antimicrobial activity against fish pathogen was isolated from gastrointestinal tract of flounder for the purpose of use as an aquaculture probiotics. From the analysis of morphological and physiological characteristics, the isolated strain was named as Lactococcus sp. HM58. Antimicrobial substance (AMS) from Lactococcus sp. HM58 showed strong growth inhibitory activity against Streptococcus sp., which is a fish pathogenic bacterium. AMS was presumed a proteinaceous compound with stability in heat and wide pH range from 2 to 10. It was started to produce in exponential growth phase and was not produced any more in stationary phase. It showed comparatively broad antimicrobial spectrum against most of gram positive bacteria used for this study. About $84\%$ of Lactococcus sp. HM58 was able to survive in the artificial gastric juice though it was low to the extent in the artificial bile juice. In the sensitivity test for various antibiotics, this strain was highly sensitive for doxycycline, erythromycin, amoxicillin clavu1anic acid and ampicillin.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.221-227
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• 2013

In total, 131 Escherichia coli isolates from surface seawater of the Gomso Bay, of Korea, were analyzed for their susceptibility to 22 different antimicrobials and for genes associated with antimicrobial resistance and virulence. According to the disk diffusion susceptibility test, the resistance to tetracycline was most prevalent (33.6%), followed by that to ampicillin (22.1%), ticarcillin (22.1%), and trimethoprim (16.8%). More than 46.6% of the isolates were resistant to at least one antimicrobial, and 22.9% were resistant to three or more classes of antimicrobials; these were consequently defined as multidrug resistant. We further found that 29 ampicillin-resistant isolates possessed genes encoding TEM-type (93.1%) and SHV-type (6.9%) ${\beta}$-lactamases. Among the 44 tetracycline-resistant isolates, tetA and tetC were found in 35 (79.5%) and 19 (43.2%), respectively, whereas tetB was detected in only three isolates (6.8%). With regard to virulence genes, merely 0.8% (n = 1) and 2.3% (n = 3) of the isolates were positive for the enteroaggregative E. coli-associated plasmid (pCVD432) gene and the enteropathogenic E. coli-specific attaching and effacing (eae) gene, respectively. Overall, these results not only provide novel insight into the necessity for seawater sanitation in Gomso Bay, but they help reduce the risk of contamination of antimicrobial-resistant bacteria.

• 공업화학
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• 제20권6호
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• pp.696-699
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• 2009

본 연구에서는 은 나노 입자와 탄산은(Silver Carbonate)을 이용하여 제조된 은나노/셀라이트(SN/C)와 탄산은/셀라이트(SC/C) 복합체의 대장균에 대한 항균특성을 조사하였다. SN/C와 SC/C 복합체의 특성은 주사전자현미경, X-선 회절법, 그리고 원자흡수분광법에 의해 알아보았다. SN/C와 SC/C 복합체의 대장균에 대한 최소 억제농도는 0.541과 0.344 ppm이었고 완전 사멸농도는 1.427과 1.623 ppm으로 나타났다. 상기의 결과로 SN/C와 SC/C 복합체의 대장균에 대한 항균효과를 확인할 수 있었다.

• 한국임상수의학회지
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• 제34권3호
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• pp.161-164
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• 2017

Bovine respiratory disease (BRD) is one of the most important diseases in calves. It causes a huge economic loss in farms. BRD in calves is concentrated during winter because of the cold weather and lack of ventilation. However, BRD during summer in calves has continuously been a problem in farms. But there is no study about pathogens of summer pneumonia in calves and antimicrobial susceptibility in Korea. Therefore, aims of this study were to identify the pathogens and their antimicrobial susceptibility in calves with summer pneumonia. One hundred and one calves (2 weeks to 5 months after birth) with clinical sign of BRD from 5 farms were selected. After sampling by deep nasal swab, bacterial isolation and identification was conducted. Also, antimicrobial susceptibility test was performed. Pasteurella spp (49.4%), Staphylococcus spp (21.5%), Actinomyces spp (12.9%), E coli (10.7%), and Mannheimia haemolytica (5.3%) were isolated. The patterns of isolated pathogens from each farm were various. Also, the susceptibility of bacteria to antibiotics was showed a variety of patterns in each farm.

• 생명과학회지
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• 제18권3호
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• pp.369-373
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• 2008

Staphylococcus intermedius (S. intermedius) has been rarely isolated from horse. In this study, we investigated the antimicrobial susceptibility patterns of S. intermedius isolated from skin lesions of Thoroughbred horse in Daegu Equestrian Association. The skin lesions were showed with dehairing and slight purulent inflammation. Bacteria were isolated from skin lesions and identified as S. intermedius by biochemical tests and MicroLog (BIOLOG, California, USA). Antimicrobial susceptibility test of S. intemedius isolates was performed with 33 antimicrobial agents (BBL, Maryland, USA) by using the agar disk diffusion method. It showed a high sensibility in the amikacin, amoxycillin/clavuramic acid, ampicillin, cefoxitin, cephalothin, chloramphenicol, ciprofloxacin, enrofloxacin, florfenicol, kanamycin, neomycin, nitrofurantoin, norfloxacin, ofloxacin, oxacillin, penicillin G, tetracycline and vancomycin. The horse was treated with penicillin, and cured completely after two weeks. The present results showed valuable information for treatment and prevention of skin disease in horse.

• 한국미생물·생명공학회지
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• 제19권3호
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• pp.235-241
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• 1991

Streptomyces melanosporofaciens로 동정된 strain 88-GT-161 균주는, 그람양성세균 및 식물병원성 곰팡이에 각각 항균활성을 나타내는 phthalate 유도체 및 염기성 마크로라이드의 새로운 항생물질을 생산하는 것으로 밝혀졌다. 이들 활성물질들의 분리. 정제과정에서 in vitro 및 in vivo(포트 시험) 항균활성을 조사하였으며, phtahalate 유도체 항생물질은 IR, NMR, 질량분석 스펙트럼 조사를 통하여 bis(2-ethylexyl) phthalate(dioctyl phthalate)로 동정하였다. Dioctyl phthalate가 Streptomyces sp.에 의하여 생산되며 생합성된 이 화합물이 항균활성을 가진다는 사실이 보고된 것은 이것이 처음이다.

• Preventive Nutrition and Food Science
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• 제9권4호
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• pp.300-305
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• 2004

Antioxidative and antimicrobial activities of essential oils of cassia (Cinnamomum cassia) and dill (Anethum graveolens L.) were investigated. Essential oils used in this study were added to soybean oil and stored at $65^{\circ}C$ for 9 days to examine their antioxidant activities using peroxide value (POV). The results showed that dill essential oil possessed a higher antioxidant activity than cassia essential oil. Strong antimicrobial activity was observed in cassia essential oil, whereas low activity was observed in dill essential oil against the test microorganisms. Heat stability and cell growth inhibitions were investigated with different concentrations of cassia oil. Results showed that cassia oil had thermal stability in a wide range of $70-160^{\circ}C$. Cassia inhibited cell growth of Bacillus cereus KCTC 1022, Micrococcus luteus A TCC 9341 and Escherichia coli ATCC 25922, but not great on Salmonella typhimurium ATCC 14028 at level of 200 ppm. In conclusion, the results indicate that dill essential oil could be a potential candidate for an antioxidative agent, while cassia essential oil could be suitable for use as an antimicrobial agent in the food industry.

• 콘크리트학회논문집
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• 제19권1호
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• pp.113-120
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• 2007

본 연구에서는 황산화세균에 의한 하수시설 콘크리트의 생화학적 부식을 저감시키기 위해 항균제 및 항균콘크리트의 개발과 성능 평가에 관한 연구를 수행하였다. 먼저 수밀성, 항균성, 균질성, 시공성 및 무해성 등 하수시설용 항균 콘크리트의 요구 성능을 제시하였으며, 개발된 항균제 및 항균 콘크리트를 요구 성능을 기준으로 평가하였다. 그 결과 액상 항균제의 분산 성능 및 항균 성능은 유효하였으며, 항균 콘크리트의 경우 비색 시험에 의해 항균 성능을 검증할 수 있었고, 유해 성분 및 유효 성분의 용출도 극히 적은 것으로 나타났다. 시공성에 있어서는 응결시간이 다소 지연되는 현상이 나타났으며, 압축강도 및 탄산화저항성은 일반 콘크리트에 비해 다소 향상되는 것으로 나타났다. 또한 세공 측정에 의한 내부공극량도 일반 콘크리트에 비해 낮게 측정되었으며, 내부 조직도 치밀하게 관찰되는 등 항균제에 의한 콘크리트의 수밀성 향상을 검증할 수 있었다. 또한 황산화 세균에 의한 생화학적 부식을 실증적으로 평가할 수 있는 인공촉진시험을 개발한 후 시험을 실시하여 평가한 결과 황산화세균의 생장이 뚜렷하게 확인되었고 그 적용성을 검증할 수 있었다.