• 생명과학회지
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• 제19권6호
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• pp.793-798
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• 2009

본 연구는 제주마에서 빈번하게 관찰되는 전신성 백모색 발생의 유전 양상과 유전적 변이와의 상관을 구명하기 위해 수행하였다. 백모색은 표현형과 MC1R 유전자형 분석 자료의 조합을 근거로 결정한 가라, 유마, 적다 등 모든 기본 모색에서 관찰되었다. 제주마에서는 타 품종들에서 KIT 유전자의 이형 접합성에 의해 발생하는 선천성 백색에 대한 잠재적 돌연변이 들은 발견되지 않았다. STX17 유전자의 intron 6 에서 4.6-kb 중복을 보유한 개체들에서 특이적으로 탈색된 백모색이 관찰되었다. 관찰기록과 STX17 유전자형에 따라 제주마에서 관찰되는 탈색된 백화현상은 총마(점진적 백화증, Gray) 로 확인되었다. 가계도 분석에서 총마 형질은 상동염색체성 우성유전형 질로 나타났으며 상동염색체성 열성형질인 albinism과도 구분되었다. 제주마에서 총마 모색이 자마 시기에는 명확하게 발현되는 않으며, 종종 다른 표현형들과 혼동을 일으키기도 하기 때문에, 총마와 이와 유사한 표현형으로 출생 시부터 혼합 모색을 나타내는 조모색, 상처 치료 후 백화, 백반 유사피부 백색증 등에 대한 추가 연구가 요구된다고 하겠다. 그럼에도 불구하고 총마와 유전적 배경의 관계를 구명한 본 연구결과는 제주마에서 분자육종을 위한 유용한 정보를 제공할 것으로 사료된다.

• 해운
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• 2호통권13호
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• pp.10-17
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• 2005

• 한국수정란이식학회지
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• 제30권3호
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• pp.183-188
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• 2015

본 연구는 제주마 집단의 모색유전자 분포 특성 및 세대별 모색 유전자 변화 양상을 분석하기 위해 제주특별자치도에서 관리하는 제주마, 1,462두에 대한 모색 관련 유전자인 MC1R, ASIP, ECA3-inversion, STX17을 분석하였다. 흑모색과 관련된 MC1R 유전자의 $E^+/E^+$와 $E^+/E^e$ 유전자형 빈도는 각각 0.122와 0.447로 조사되었고, 적색(chestnut) 유전자형인 $E^e/E^e$ 유전자형 빈도는 0.429로 확인되었다. ASIP 유전자의 $A^A/A^A$, $A^A/A^a$ 및 $A^a/A^a$ 유전자형 빈도는 각각 0.46, 0.448, 0.091로 확인되어 $A^a/A^a$ 유전자형 빈도가 낮았다. 토비아노(Tobiano) 형태를 발현하는 To/To와 +/To 유전자형은 각각 0.001과 0.119로 토비아노 형태의 모색은 12%를 점유하고 있었다. 회색 모색과 관련된 STX17의 G/G와 G/g 유전자형의 빈도는 각각 0.002와 0.680로 나타나 제주마 집단에 회색마는 68.2%를 점유하였다. 세대별 모색 변화는 MC1R, ASIP 유전자에서는 큰 변화를 확인할 수 없었다. ECA3-inversion에서는 토비아노를 발현하는 To allele은 세대변화에 따라 유의적으로 감소하였고(p<0.05), 회색 모색과 관련된 STX17 G allele은 세대변화에 따라 유의적으로 증가하였다(p<0.05). 본 연구결과, 제주마 집단의 모색 다양성을 유지하기 위해서는 종마 선정 단계에 모색 유전자의 검토가 필요한 것으로 사료되었다.

• 한국미생물·생명공학회지
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• 제48권2호
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• pp.121-128
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• 2020

Diarrhea is a major public health concern associated with pathogenic Escherichia coli infections. Food-borne pathogenic E. coli can lead to large diarrheal outbreaks and hence, there is a need to estimate the frequency of pathogenic E. coli load in the various types of meat available in markets. In the present study, we classified and characterized diarrheagenic E. coli isolates collected from 399 raw meat samples from retail sources in Korea. Shiga toxin-producing E. coli (STEC) were detected in 11 (9.7%) samples, including nine strains (8.0%) in beef and two strains (1.8%) in chicken. The frequency of the detected virulence markers were as follows: astA, 28.3%; escV,18.6%; eaeA,17.7%; ent, 7.0%; EHEC-hly, 4.4%; stx1, 3.5%; and stx2, 3.5%. We did not observe any typical EPEC, EIEC, or ETEC virulence determinants in any of the samples. The STEC serotype O26 was detected in one sample, but no other serogroups (O91, O103, O128, O157, O145, O111, and O121) were found. Further research is needed to better understand the virulence mechanism of STEC serotypes, their ecology, and prevalence in animals, food, and the environment. These results will help improve risk assessment and predict the sources of food poisoning outbreaks.

• 한국식품위생안전성학회지
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• 제32권2호
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• pp.129-134
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• 2017

병원성 대장균군은 전세계적으로 식중독을 발생하는 중요한 병원균으로 알려져 있다. 국내 유통중인 생닭과 조리된 닭가공품 356시료에서 대장균 80균주(22.5%)를 분리하여 병원성 유전자 multiplex PCR를 이용하여 분석한 결과 astA 유전자가 26균주(32.5%)에서 검출되었으며, escV 유전자는 17균주(21.3%) eaeA 유전자는 16균주(20.0%) 검출되었다. 특히 식품에서 문제가 되는 장출혈성 대장균 유전자 stx 1는 3균주(3.8%)와 stx 2, EHEC-hly는 각 1균주(1.3%)에서 검출되었다. 병원성 유전자를 토대로 STEC, EPEC, EHEC, EIEC or EAEC의 병원성 대장균으로 분류한 결과 45균주(56.3%)가 검출되었으며 typical EPEC, EIEC and ETEC의 병원성 대장균은 검출되지 않았다. STEC 병원성 대장균은 O152, O1, O116, O26, O25, O119, O153 혈청형이 분리되었다. 특히 생닭에서 병원성 대장균에 대한 검출률이 높으므로 생닭을 가공 조리 시 교차 오염이 발생하기 않도록 조리 도구, 조리 환경에 대한 철저한 관리가 필요하다고 생각된다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2009년 추계학술발표대회
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• pp.97-97
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• 2009

The use of thin plate increases due to the need for light weight in large ship. Thin plate is easily distorted and has residual stress by welding heat. Therefore, the thin plate should be carefully joined to minimize the welding deformation which costs time and money for repair. For one effort to reduce welding deformation, it is very useful to predict welding deformation before welding execution. There are two methods to analyze welding deformation. One is simple linear analysis. The other is nonlinear analysis. The simple linear analysis is elastic analysis using the equivalent load method or inherent strain method from welding experiments. The nonlinear analysis is thermo-elastic analysis which gives consideration to the nonlinearity of material dependent on temperature and time, welding current, voltage, speed, sequence and constraint. In this study, the welding deformation is analyzed by using thermo-elastic method for PCTC(Pure Car and Truck Carrier) which carries cars and trucks. PCTC uses thin plates of 6mm thickness which is susceptible to welding heat. The analysis dimension is 19,200mm(length) * 13,825mm(width) * 376mm(height). MARC and MENTAT are used as pre and post processor and solver. The boundary conditions are based on the real situation in shipyard. The simulations contain convection and gravity. The material of the thin block is mild steel with $235N/mm^2$ yield strength. Its nonlinearity of conductivity, specific heat, Young's modulus and yield strength is applied in simulations. Welding is done in two pass. First pass lasts 2,100 second, then it rests for 900 second, then second pass lasts 2,100 second and then it rests for 20,000 second. The displacement at 0 sec is caused by its own weight. It is maximum 19mm at the free side. The welding line expands, shrinks during welding and finally experiences shrinkage. It results in angular distortion of thin block. Final maximum displacement, 17mm occurs around welding line. The maximum residual stress happens at the welding line, where the stress is above the yield strength. Also, the maximum equivalent plastic strain occurs at the welding line. The plastic strain of first pass is more than that of second pass. The flatness of plate in longitudinal direction is calculated in parallel with the direction of girder and compared with deformation standard of ${\pm}15mm$. Calculated value is within the standard range. The flatness of plate in transverse direction is calculated in perpendicular to the direction of girder and compared with deformation standard of ${\pm}6mm$. It satisfies the standard. Buckle of plate is calculated between each longitudinal and compared with the deformation standard. All buckle value is within the standard range of ${\pm}6mm$.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.128-128
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• 2003

The annually outbreak of paralytic shellfish poisoning (PSP) were caused by toxic dinolagellate A. tamarense and A. catenella in Korea. The purpose of this study were to investigate the distribution of PSP-causative organisms, A. tamarense and A. catenella and their species classification. Sediment (Saemangeum, the south open sea) and water samples (southeastern coast) were sampled to establish clonal isolates in 2003. After isolation and purification, strains were cultured under $17^{\circ}C$, f/2 media, 14:10=L:D cycle. PST analysis and species identification were performed by HPLC-FD method and specific DNA probe, respectively. Thirty-ons strains were isolated from the Saemangeum reclamation, southeastern coast including Jinhae Bay and south open sea. PSTs were detected in all cultured strains. In eight strains from south offshore, major toxin components are GTX5, C1/2 and minors are GTX3/4, dcGTX3, neoSTX. Sixteen strains from south coastal area have GTX1/4, neoSTX, C1/2 as major toxin components and GTX2/3 as minors. Seven strains from the Saemangeum reclamation have GTX5, C1/2 as major toxin components and GTX1/2/3/4 as minors. Thus, among eight south offshore isolates, four A. tamarense have more toxic (38.31~l19.16 fmol.$cell^{-1}$) than A. catenella (3.78~13.13 fmol.$cell^{-1}$). With the previous results of different toxin composition, toxin components and toxin contents, .it is toxin profile that could used to diagnosis of regional toxic population and geographical distribution of both A. tamarense and A. catenella and their toxigenic strains.

• 한국동물위생학회지
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• 제28권1호
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• pp.71-79
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• 2005

In this study, a total of 2,119 samples was taken from bovine feces and carcass from March 2002 to December 2003. And those were examined for the presence of enterohemorrhagic E coli O157:H7. The properties of the isolates were characterized for biochemical features, serotypes, virulence genes and antimicrobial susceptibility. Forty five strains($3.7\%$) of E coli O157:H7 were isolated from 1,208 fecal samples and were not detected in carcass using immunomagnetic separation technique and selective media. In multiplex PCR using stx1, stx2, eaeA and hlyA primers, the amplified bands at 180 bp, 255bp, 384bp and 534bp were observed, respectively. In antimicrobial susceptibility test, all isolates were susceptible to amoxicillin/clavulanic acid and cefazolin. The isolates were most resistant to sulfisoxazole($24.4\%$), followed by streptomycin($22.2\%$), tetracycline($20.0\%$). Eight strains($17.8\%$) of 45 isolates showed the multi-resistant patterns with over 3 drugs.

• 한국동물위생학회지
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• 제42권2호
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.

• 한국방사선학회논문지
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• 제17권3호
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• pp.481-487
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• 2023

본 연구에서는 15 MV를 이용한 전립샘암의 세기조절방사선치료 시 빔의 개수에 따른 광중성자선량의 부작용 발생률을 분석하고자 한다. 전립샘암 세기조절방사선치료의 방사선치료계획설계는 1회 처방선량 220 cGy, 전체 치료 횟수는 33회로 총 7260 cGy로 수립하였다. 실험에 사용된 선형가속기는 Varian의 True Beam STx(Varian, USA)이며, 계획용 표적체적(Planning target volume; PTV)에 15 MV로 광중성자 선량이 발생되도록 하였다. 치료계획의 설계는 Eclipse System (Varian Ver 10.0, USA)을 사용하여 세기조절방사선치료 5, 7, 9 portals로 하였다. 광중성자 선량 측정을 위해 광자극발광선량계 (Optically stimulated luminescence albedo neutron dosimeter, Landauer Inc., USA)를 사용하였다. 세기조절방사선치료 5 portals 시 1,000명당 1.7명, 7 portals 시 1,000명당 1.8명, 9 portals 시 1,000명당 2.0명이 광중성자 선량으로 인하여, 갑상샘에 부작용을 나타낼 확률임을 산출하였다. 본 연구는 세기조절방사선치료 시 2차 피폭선량의 위험성을 연구하여, 향후 방사선의 확률적 영향과 관련된 의미 있는 자료로 활용될 수 있기를 기대한다.