• 한국축산식품학회지
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• 제40권5호
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• pp.746-757
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• 2020

Enterotoxigenic Escherichia coli (ETEC) is the major pathogenic E. coli that causes diarrhea and edema in post-weaning piglets. In this study, we describe the morphology and characteristics of ØCJ19, a bacteriophage that infects ETEC, and performed genetic analysis. Phage ØCJ19 belongs to the family Myoviridae. One-step growth curve showed a latent phase of 5 min and burst size of approximately 20 phage particles/infected cell. Phage infectivity was stable for 2 h between 4℃ and 55℃, and the phage was stable between pH 3 and 11. Genetic analysis revealed that phage ØCJ19 has a total of 49,567 bases and 79 open reading frames (ORFs). The full genomic sequence of phage ØCJ19 showed the most similarity to an Escherichia phage, vB_EcoS_ESCO41. There were no genes encoding lysogeny, toxins, virulence factors, or antibiotic resistance in this phage, suggesting that this phage can be used safely as a biological agent to control ETEC. Comparative genomic analysis in terms of the tail fiber proteins could provide genetic insight into host recognition and the relationship with other coliphages. These results showed the possibility to improve food safety by applying phage ØCJ19 to foods of animal origin contaminated with ETEC and suggests that it could be the basis for establishing a safety management system in the animal husbandry.

• 대한본초학회지
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• 제21권1호
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• pp.1-7
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• 2006

Objectives: To find out the effects GGT1, an antiobestic drug widely used clinics, has on the amount of feed intake, the amount of change in the body weight and the food efficiency ratio using the data from the hGHTg obese male rats. Also, to evaluate in terms of antiobestic effects, the difference between GGT1 and reductil (sibutramine), which has been approved by the FDA of the United States. Methods: We measured the change in body weight and the amount of feed intake for 8 weeks by categorizing the hGHTg obese male rats into three groups: the control group, the GGT1 group, and the reductil (RD) group. We also evaluated the antiobestic effect by calculating the food efficiency ratio, which is the increase of bodyweight divided by the amount of feed intake. Results: In case of body weight, moderate slope of the curve in the graph of GGT1 group could mean that the weight is decreasing as time flows. In case of food efficiency ratio, the p-value was 0.745 in a test for determining if an interaction exists between the group and the point of measurement, meaning that it does not exist; also, the p-value in a test for the effect of level of repetition in food efficiency ratio according to the point of measurement equaled 0.002. Conclusion: The drug-treated groups had a greater inhibitory effect in feed intake than the control group. The results showed the food efficiency ratio had a tendency to decrease. The GGT1 group in particular was under a greater effect than the RD group.

• 급식외식위생학회지
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• 제1권1호
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• pp.27-35
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• 2020

Salt is a common seasoning agent used in various processed foods, especially in kimchi and salted seafood (jeotgal). This study was conducted to investigate the efficacy of salt with antimicrobial substances (acetic acid, garlic extract, carvacrol, nisin, thymol, and their combination (acetic acid+nisin+thymol)) on improvement of antibacterial effects of salt against foodborne pathogens. Salt (10%) was prepared using six different types of 0.2% natural antimicrobial substances. The antibacterial effect of salt combined with natural antimicrobial substances was evaluated against foodborne pathogens using the broth micro-dilution method and growth curve plotted using absorbance measurements. For the five foodborne pathogens, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of salt without antimicrobial substances as control were in the range of 24~>50,000 ㎍/mL and >50,000 ㎍/mL, respectively. Salt with nisin, thymol, or garlic extract showed strong inhibitory effects and their MIC against L. monocytogenes were 49, 12,500, and 24 ㎍/mL, respectively. In particular, salt with nisin showed inhibitory activities against Gram-positive bacteria. However, all the antimicrobial substances were less effective against Gram-negative bacteria such as E. coli O157:H7 and S. Typhimurium than Gram-positive bacteria. These results could be used for the development of salt with natural antimicrobial substances especially targeted against L. monocytogenes. This would enable the lowering of saline concentration while improving the storability of food.

• Korean Journal of Radiology
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• 제20권5호
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• pp.781-790
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• 2019

Objective: To assess the relationship between contrast-enhanced ultrasound (CEUS) parameters and perfusion CT (PCT) parameters of gastric cancers and their correlation with histologic features. Materials and Methods: This prospective study was approved by our Institutional Review Board. We included 43 patients with pathologically-proven gastric cancers undergoing CEUS using SonoVue^® (Bracco) and PCT on the same day. Correlation between the CEUS parameters (peak intensity [PI], area under the curve [AUC], rise time [RT] from 10% to 90% of PI, time to peak [TTP_US], and mean transit time [MTT_US]) and PCT parameters (blood flow, blood volume, TTP_CT, MTT_CT, and permeability surface product) of gastric cancers were analyzed using Spearman's rank correlation test. In cases of surgical resection, the CEUS and PCT parameters were compared according to histologic features using Mann-Whitney test. Results: CEUS studies were of diagnostic quality in 88.4% (38/43) of patients. Among the CEUS parameters of gastric cancers, RT and TTP_US showed significant positive correlations with TTP_CT (rho = 0.327 and 0.374, p = 0.045 and 0.021, respectively); PI and AUC were significantly higher in well-differentiated or moderately-differentiated tumors (n = 4) than poorly-differentiated tumors (n = 18) (p = 0.026 and 0.033, respectively), whereas MTT_CT showed significant differences according to histologic types (poorly cohesive carcinoma [PCC] vs. non-PCC), T-staging (≤ T2 vs. ≥ T3), N-staging (N0 vs. N-positive), and epidermal growth factor receptor expression (≤ faint vs. ≥ moderate staining) (p values < 0.05). Conclusion: In patients with gastric cancers, CEUS is technically feasible for the quantification of tumor perfusion and may provide correlative and complementary information to that of PCT, which may allow prediction of histologic features.

• 기술혁신연구
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• 제11권1호
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• pp.147-176
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• 2003

This Paper Presents a new measurement technique to derive the level of BSRC (Basic Science and Research Capacity) index by use of the factor analysis which is extended with the assumption of the standard normal probability distribution of the selected explanatory variables. The new measurement method is used to forecast the gap of Korea's BSRC level compared with those of major OECD countries in terms of time lag and to make their international comparison during the time period of 1981∼1999, based on the assumption that the BSRC progress function of each country takes the form of the logistic curve. The US BSRC index is estimated to be 0.9878 in 1981, 0.9996 in 1990 and 0.99991 in 1999, taking the 1st place. The US BSRC level has been consistently the top among the 16 selected variables, followed by Japan, Germany, France and the United Kingdom, in order. Korea's BSRC is estimated to be 0.2293 in 1981, taking the lowest place among the 16 OECD countries. However, Korea's BSRC indices are estimated to have been increased to 0.3216 (in 1990) and 0.44652 (in 1999) respectively, taking 10th place. Meanwhile, Korea's BSRC level in 1999 (0.44652) is estimated to reach those of the US and Japan in 2233 and 2101, respectively. This means that Korea falls 234 years behind USA and 102 years behind Japan, respectively. Korea is also estimated to lag 34 years behind Germany, 16 years behind France and the UK, 15 years behind Sweden, 11 years behind Canada, 7 years behind Finland, and 5 years behind the Netherlands. For the period of 1981∼1999, the BSRC development speed of the US is estimated to be 0.29700. Its rank is the top among the selected OECD countries, followed by Japan (0.12800), Korea (0.04443), and Germany (0.04029). the US BSRC development speed (0.2970) is estimated to be 2.3 times higher than that of Japan (0.1280), and 6.7 times higher than that of Korea. German BSRC development speed (0.04029) is estimated to be fastest in Europe, but it is 7.4 times slower than that of the US. The estimated BSRC development speeds of Belgium, Finland, Italy, Denmark and the UK stand between 0.01 and 0.02, which are very slow. Particularly, the BSRC development speed of Spain is estimated to be minus 0.0065, staying at the almost same level of BSRC over time (1981 ∼ 1999). Since Korea shows BSRC development speed much slower than those of the US and Japan but relative]y faster than those of other countries, the gaps in BSRC level between Korea and the other countries may get considerably narrower or even Korea will surpass possibly several countries in BSRC level, as time goes by. Korea's BSRC level had taken 10th place till 1993. However, it is estimated to be 6th place in 2010 by catching up the UK, Sweden, Finland and Holland, and 4th place in 2020 by catching up France and Canada. The empirical results are consistent with OECD (2001a)'s computation that Korea had the highest R&D expenditures growth during 1991∼1999 among all OECD countries ; and the value-added of ICT industries in total business sectors value added is 12% in Korea, but only 8% in Japan. And OECD (2001b) observed that Korea, together with the US, Sweden, and Finland, are already the four most knowledge-based countries. Hence, the rank of the knowledge-based country was measured by investment in knowledge which is defined as public and private spending on higher education, expenditures on R&D and investment in software.

• 한국잡초학회지
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• 제18권2호
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• pp.128-135
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• 1998

뚝새풀의 초생재배(草生栽培)에 의한 사과원 잡초(雜草) 방제(防除)의 실용화(實用化) 가능성(可能性)을 검토(檢討)하고자 뚝새풀 발생(發生) 생태(生態)에 관한 몇 가지 시험(試驗) 결과(結果)를 요약(要約)하면 다음과 같다. 1 뚝새풀 종자(種子)의 파종(播種) 시기별(時期別)출아(出芽) 소요일수(所要日數)는 9월(月) 20일(日) 파종(播種)이 일(日)로 가장 짧았고, 11월(月) 25일(日) 파종(播種)에서 111일(日)이 소요(所要)되어 가장 길었으며, 출아(出芽) 소요(所要) 적산온도(積算溫度)는 3월(月) 15일(日) 파종(播種)이 $139^{\circ}C$로 가장 적었고, 8월(月) 10일(日) 파종(播種)에서는 $988^{\circ}C$로 가장 많이 소요(所要)되었다. 2 사과원에서의 뚝새풀 생육양상(生育樣相)은 3월(月)부터 8월(月) 사이에 S자형(字型)의 생장곡선(生長曲線)을 나타내었고, 초장(長草)과 건물중(乾物重)이 3월(月) 중순(中旬)에서 4월(月) 중순(中旬)사이에 가장 많이 증가(增加)하였으며 5월(月) 중순(中旬) 이후(以後)로는 증가율(增加率)이 거의 정체(停滯)되었다. 3. 뚝새풀을 초생재배(草生栽培)한 사과원에서 뚝새풀을 제외(除外)한 초종(草種)으로는 발생량(發生量)이 망초>왕고들빼기>냉이>꽃다지 순(順)이었고, 뚝새풀의 발생(發生)이 거의 없는 포장(圃場)에서는 냉이가 가장 많이 발생(發生)하였고 왕고들빼기>망초>꽃다지 순(順)으로 발생(發生)되었다. 4. 뚝새풀의 생육(生育) 재생기(再生期)인 3월(月) 중순(中旬)에 뚝새풀의 우점도(優點度)가 90%정도(程度)가 되면 생육(生育) 후기(後期)까지 문제(問題) 잡초(草種)인 망초 왕고들빼기 냉이 등(等)을 효과적(效果的)으로 방제(防除)할 수 있었으나 생육(生育) 재생기(再生期)에 우점도(優點度)가 20%미만(未滿)이면 뚝새풀의 생육(生育) 성기(盛期)인 5월(月) 까지는 다른 잡초(雜草)의 발생(發生)이 경감(輕減)되었으나 이후(以後) 점차(漸次) 증가(增加)하였다. 5. 이상(以上)의 결과(結果)에서 사과원에서의 뚝새풀 초생재배(草生栽培)는 다른 잡초(雜草)들의 발생(發生)을 억제(抑制)시켜 잡초방제(雜草防除)의 성력화(省力化)와 하절기(夏節期)의 과다(過多)한 지온상승(地溫上昇)을 방지(防止)하여 과수(果樹)의 생육(生育)을 양호(良好)하게 할 것으로 기대(期待)된다.

• 한국식품위생안전성학회지
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• 제26권1호
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• pp.25-30
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• 2011

본 연구에서는 식중독 예방과 식품의 안전성 확보 및 정량적 미생물 위해평가에 활용하기위하여, Gompertz model과 Baranyi model을 이용하여 샐러드용 신선채소에서 L. monocytogenes의 SGR에 관한 성징예측모델(SGR by Gompertz equation=-0.1606+$0.0574^*Temp$+$0.0009^*Temp^*Temp$, SGR by Baranyi equation=0.3502-$0.0496^*Temp$+$0.0022^*Temp^*Temp$)을 개발하였다. 개발된 모델의 적합성 평가를 위해 MSE, Bf, 및 Af factor를 산출하였다. 샐러드용 신선 채소의 MSE, Bf, Af는 Gompertz model식을 적용한 경우 0.002718, 1.050084, 1.160767, Baranyi model 식을 적용한 경우 0.055186, 1.931472, 2.137181으로 나타나 Gompertz model식을 적용하여 개발한 예측모델이 Baranyi model 식을 이용하여 개발한 예측모델에 비해 적합성이 높은 것으로 나타났다. Gompertz model식을 활용하여 본 연구에서 개발된 샐러드용 신선 채소에서의 L. monocytogenes 성장 예측모델은 신선 채소류를 생산, 가공, 보관 및 판매하는 산업체에서 널리 활용 가능할 것으로 판단되며, 더욱 정확한 예측모델 개발을 위해서는 pH 및 수분활성도 등 다양한 변수에 따른 미생물의 성장패턴 변화 등에 관한 연구가 추가적으로 시행되어야 할 것으로 생각되어 진다.

• Journal of Animal Science and Technology
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• 제62권5호
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• pp.668-681
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• 2020

The purpose of this study was aimed to isolate a Salmonella Typhimurium-specific phage (KFS-ST) from washing water in a poultry processing facility and to investigate the feasibility of the KFS-ST as a novel bio-receptor for the magnetoelastic (ME) biosensor method. KFS-ST against S. Typhimurium was isolated, propagated, and purified using a CsCl-gradient ultracentrifugation. Morphological characteristics of KFS-ST were analyzed using transmission electron microscopy (TEM). Its specificity and efficiency of plating analysis were conducted against 39 foodborne pathogens. The temperature and pH stabilities of KFS-ST were investigated by the exposure of the phage to various temperatures (-70℃-70℃) and pHs (1-12) for 1 h. A one-step growth curve analysis was performed to determine the eclipse time, latent time and burst size of phage. The storage stability of KFS-ST was studied by exposing KFS-ST to various storage temperatures (-70℃, -20℃, 4℃, and 22℃) for 12 weeks. KFS-ST was isolated and purified with a high concentration of (11.47 ± 0.25) Log PFU/mL. It had an icosahedral head (56.91 ± 2.90 nm) and a non-contractile tail (225.49 ± 2.67 nm), which was classified into the family of Siphoviridae in the order of Caudovirales. KFS-ST exhibited an excellent specificity against only S. Typhimurium and S. Enteritidis, which are considered two of the most problematic Salmonella strains in the meat and poultry. However, KFS-ST did not exhibit any specificity against six other Salmonella and 27 non-Salmonella strains. KFS-ST was stable at temperature of 4℃ to 50℃ and at pH of 4 to 12. The eclipse time, latent time, and burst size of KFS-ST were determined to be 10 min, 25 min and 26 PFU/ infected cell, respectively. KFS-ST was relatively stable during the 12-week storage period at all tested temperatures. Therefore, this study demonstrated the feasibility of KFS-ST as a novel bio-receptor for the detection of S. Typhimurium and S. Enteritidis in meat and poultry products using the ME biosensor method.

• 한국버섯학회지
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• 제15권4호
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• pp.249-253
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• 2017

Cellulase와 xylanase 분비능이 우수한 세균을 분리하기 위하여 부여군 석성면 지역의 양송이 재배농장으로부터 수확후배지를 수집하였다. 양송이 수확후배지로부터 12종의 균주를 분리하였으며 이 중 cellulase와 xylanase 활성이 가장 우수한 균주 NO12를 최종 선발하였다. 분리균 NO12의 생리적 생화학적 특성은 Bacillus ID kit와 MicroLog system을 이용하여 조사하였으며 분리균 NO12는 Bacillus subtilis와 유사한 특징을 나타내었다. 분리균 NO12의 16S rDNA 염기서열도 B. subtilis와 99.2%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 NO12는 B. subtilis NO12로 동정되었다. 분리균이 분비하는 cellulase와 xylanase 활성은 분리균이 증식함에 따라 대수증식기 중반부터 급격히 증가하였고 정지기에 진입하면 효소활성이 더 이상 증가하지 않는 것으로 나타났으며 xylanase 활성은 대수증식기 초기부터 지속적으로 증가하여 대수증식기 중반에 최대활성을 나타내었다.

• 한국버섯학회지
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• 제13권4호
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• pp.305-309
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• 2015

Cellulase와 xylanase 분비능이 우수한 부숙촉진 세균을 분리하기 위하여 진주시 집현면 소재의 느타리버섯 재배농장으로부터 느타리버섯 수확후배지를 수집하였다. 느타리버섯 수확후배지로부터 19종의 균주를 분리하였으며 이 중 cellulase와 xylanase을 동시에 분비하는 균주를 최종 선발하여 CA105로 명명하였다. Bacillus ID kit와 VITEK 2 system를 이용하여 분리균 CA105의 생화학적 특성을 조사한 결과에서도 분리균 CA105은 B. subtilis와 유사한 특징을 나타내었으며 16S rRNA 염기서열 분석 결과에서는 B. subtilis와 98.9%의 상동성을 나타내었다. 이와 같은 결과를 종합하여 분리균 CA105은 Bacillus subtilis CA105로 동정되었다. 분리균이 분비하는 cellulase와 xylanase 활성은 분리균이 증식함에 따라 대수증식기 중반부터 급격히 증가하였고 정지기에 진입하면 효소활성이 더 이상 증가하지 않는 것으로 나타났다.