• 한국식품위생안전성학회지
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• 제11권4호
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• pp.243-259
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• 1996

This study was performed to investigate the induction of experimental atherosclerosis in rats and inhibitory effects of aloe vera on progression of atherosclerosis in rats. Adose range finding study of cholesterol and vitamin D2 for the induction of atherosclerosis and studies on the subchronic effect of aloe vera and on the chronic effect of aloe vera were carried out. A total of 3-week old 125 male rats of Sprague-Dawley were divided into 25 groups and fed with the diet containing cholesterol (0.1, 0.2, 0.3, 0.5, 1.0 and 2.0%) and vitamin D2 (500, 5000, 50000 and 500, 000 IU/100 g) for 4 weeks. 35 male rats were divided into 7 groups and fed with the diet containing aloe vera with 1.0% of cholesterol and 50, 000 IU/100 g of vitamin D2 for 4 weeks. 200 male rats were divided into 5 groups and fed with cholesterol and vitamin D2 for 6 and 12 months. Growth, clinical and pathological changes of rats in the three experiments were observed. The results were as follows: 1. In the dose-range finding study, feed intake, feed efficiency ratio and weight to body weight were increased in all of the feed groups containing 500, 000 IU/100 g of vitamin D2. Serum biochemical values of total cholesterol, high-density lipiprotein cholesterol (HDL-cholesterol), triglyceride, calcium, inorganic phosphorous and chloride of male rats in treated groups. The aorta and coronary artery of rats in all of the diet group containing 500, 000 IU/100 g of vitamin D2 showed typical atherosclerotic lesions. 2. Male rats fed with the diet containing aloe vera with 1.0% cholesterol and 50, 000 IU/100 g of vitamin D2 for 6 and 12 months did not show significant difference of diet intake and weight gain, and relative organ weight. The level of serum HDL-cholesterol and triglyceride recovered to the normal range by the aloe vera ingestation. 3. The aorta showed irregular appearence in the tunica intima with swelling, necrosis and calcification. The aorta of rat fed aloe vera diet showed no pathological lesions such as atherosclerosis of aorta. Aloe vera could have a helpful effect of vitamin D2 and cholesterol induced atherosclerosis in rats. Long-term supplementation of aloe vera may slow down the process of experimental atherosclerosis in rats have effects on the development of atherosclerosis.

• 한국식품저장유통학회지
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• 제18권5호
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• pp.746-754
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• 2011

배합사료를 공급한 양식 넙치와 생사료를 공급한 양식넙치의 핵산 관련 물질 및 유리아미노산 측정을 통한 품질의 차이를 비교하였다. 넙치 등근육의 핵산관련물질은 모든 실험사료구에서 공통적으로 AMP 함량이 가장 높았고 그 다음으로 IMP의 함량이 높았다. 공급한 사료에 따라서 HxR의 성분에는 유의적인 차이(p<0.05)를 보였으나, 핵산 관련물질 조성의 분포양상은 비슷한 경향을 나타내었다. 또한, 넙치 지느러미살의 핵산 관련 물질 조성 중 공급한 사료의 종류에 상관없이 IMP 함량이 공통적으로 가장 높게 나타났으나 함량에는 유의적인 차이를 보이지 않았다. 한편, 어육의 초기 변화 정도를 측정하는 K value는 넙치 등근육에서 MP, CEP 및 FEP의 공급구가 각각 9.63%, 9.83% 및 5.84%를 나타내었고, 넙치 지느러미 살에서는 각각 15.71%, 11.22% 및 17.60%를 나타내었다. 넙치를 사육하는 동안 공급하는 사료의 종류에 따라 등 근육 및 지느러미살의 특정 유리아미노산 함량에는 유의적인 차이가 있으나, 전반전인 유리아미노산의 조성에는 큰 차이가 없었다. 유리아미노산 중에서 taurine 함량이 모든 실험사료구에서 공통적으로 가장 높았고, CEP 및 FEP 공급구는 asparagine과 citrulline의 함량이 MP 공급구보다 높았다. 이처럼, 넙치를 사육하는 동안 공급하는 사료의 종류에 따라 등근육 및 지느러미살의 특정 유리아미노산의 함량에 차이가 나는 것으로 볼 때, 맛과 풍미에 큰 영향을 미치는 유리아미노산 조성의 규명은 기호도를 예측할 수 있는 효과적인 방법이라 생각된다.

• 한국식품위생안전성학회지
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• 제21권4호
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• pp.244-249
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• 2006

Amoxicillin을 넙치, 조피볼락 그리고 참돔에 각각 400 mg/kg bw/day의 용량으로 7일 동안 사료와 혼합하여 경구 투여한 다음, 휴약기간 동안 근육조직 내 잔류 분포를 조사하였다. 실험어는 해수 중에서 일정한 크기의 케이지에 일반 상업용 사료를 주어 사육하였고, 실험에 사용하기에 앞서 15일 동안 환경에 적응시켰다. 약제 투여 후, 근육시료는 1, 2, 3, 4, 그리고 5일에 각각의 실험어를 대상으로 채취하였다. Amoxicillin의 잔류분석은 형광검출기를 부착한 고속액체크로마토그래피를 이용하여 분석하였다. Amoxicillin의 회수율은, 0.05mg/kg의 농도에서 84.3-101.3%, 0.1mg/kg의 농도에서는 75.0-91.5%를 보였다. 투약 후 1일에는, 참돔의 근육 중 amoxicillin의 잔류농도가 넙치와 조피볼락의 근육 중 잔류농도에 비하여 높았으나 통계적 유의성은 없었으며, 투약 후 4일에는, 모든 근육 시료에서 amoxicillin이 검출되지 않았다. 이상의 결과로부터, amoxicillin의 사료혼합을 통한 경구 투여는 넙치, 조피볼락 그리고 참돔의 근육 중에서 안전휴약기간(7일) 보다도 체래 소실이 빨리 일어나는 것으로 추정되는 바, 안전휴약기간을 준수한다면 amoxicillin의 어류 근육 조직 내 잔류로부터 안전할 것으로 사료된다.

• 한국식품위생안전성학회지
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• 제29권2호
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• pp.85-91
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• 2014

Deoxynivalenol (DON) and related trichothecene mycotoxins are extensively distributed in the cereal-based food and feed stuffs worldwide. Recent climate changes and global grain trade increased chance of exposure to more DON and related toxic metabolites in poorly managed production systems. Monitoring the biological and environmental exposures to the toxins are crucial in protecting human and animals from toxicities of the hazardous contaminants in food or feeds. Exposure biomarkers including urine DON itself are prone to shift to less harmful metabolites by intestinal microbiota and liver metabolic enzymes. De-epoxyfication of DON by gut microbes such as Eubacterium strain BBSH 797 and Eubacterium sp. DSM 11798 leads to more fecal secretion of DOM-1. By contrast, most of plant-derived DON-glucoside is also easily catabolized to free DON by gut microbes, which produces more burden to body. Phase 2 hepatic metabolism also contributes to the glucuronidation of DON, which can be useful urine biomarkers. However, chemical modification could be very typical depending on the anthropologic or genetic background, luminal bacteria, and hepatic metabolic enzyme susceptibility to the toxins in the diet. After toxin exposure, effect biomarkers are also important in estimating the linkage and mechanisms of foodborne diseases in human and animal population. Most prominent adverse effects are demonstrated in the DON-induced immunological and behavioral disorders. For instance, acutely elevated interleukin-8 from insulted gut exposed to dietaty DON is a dominant clinical biomarker in human and animals. Moreover, subchronic exposure to the toxins is associated with high levels of serum IgA, a biological mediator of IgA nephritis. In particular, anorexia monitoring using mouse models are recently developed to monitor the biological activities of DON-induced feed refusal. It is also mechanistically linked to alteration of serotoin and peptide YY, which are promising biomarkers of neurological disorders by the toxins. As animal-alternative biomonitoring, huamn enterocyte-based assay has been developed and more realistic gut mimetic models would be useful in monitoring the effect biomarkers in resposne to toxic contaminants in the future investigations.

• Toxicological Research
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• 제16권4호
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• pp.302-309
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• 2000

The purpose of this study is to investigate toxic effects of iso-butylalcohol (iBA) in Sprague-Dawley (SD) rats under the exposure of 6 hours a day, 5 days a week for 13 weeks by inhalation, and to evaluate the occupational safety of iBA in comparison with the permissible exposure level (PEL) stipulated by the Occupational Safety and Health Administration (OSHA). iBA did not induce any abnormal changes from the aspects of clinical signs, feed consumption, ophthalmic test, urinalysis, hematology and blood chemistry during and at the terminal of the inhalation toxicity tests. We did not find any abnormal findings in the gross and microscopic observations due to the inhalation of iBA. There was no alteration in relative organ weights by the inhalation of iBA. No observed adverse effect level (NOAEL) of iBA was considered to be more than 3,000 ppm in rats under the inhalation of 6 hours a day, 5 days a week for 13 weeks. Fifty ppm of iBA, the PEL regulated by OSHA, is too conservative for working places. As iBA showed no abnormal observations in all the experimental parameters at any concentration under this experimental condition, we suggest that 150 ppm is safe enough for the PEL of iBA in the working areas, even taking into onsideration that OSHA lowered the PEL to 50 ppm for fear of the probable risk of its skin irritation.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.36-48
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• 2022

As a valid numerical method to obtain a high-resolution result of a flow field, computational fluid dynamics (CFD) have been widely used to study coolant flow and heat transfer characteristics in fuel rod bundles. However, the time-consuming, iterative calculation of Navier-Stokes equations makes CFD unsuitable for the scenarios that require efficient simulation such as sensitivity analysis and uncertainty quantification. To solve this problem, a reduced-order model (ROM) based on proper orthogonal decomposition (POD) and machine learning (ML) is proposed to simulate the flow field efficiently. Firstly, a validated CFD model to output the flow field data set of the rod bundle is established. Secondly, based on the POD method, the modes and corresponding coefficients of the flow field were extracted. Then, an deep feed-forward neural network, due to its efficiency in approximating arbitrary functions and its ability to handle high-dimensional and strong nonlinear problems, is selected to build a model that maps the non-linear relationship between the mode coefficients and the boundary conditions. A trained surrogate model for modes coefficients prediction is obtained after a certain number of training iterations. Finally, the flow field is reconstructed by combining the product of the POD basis and coefficients. Based on the test dataset, an evaluation of the ROM is carried out. The evaluation results show that the proposed POD-ROM accurately describe the flow status of the fluid field in rod bundles with high resolution in only a few milliseconds.

• 한국식품위생안전성학회지
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• 제31권6호
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• pp.432-438
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• 2016

본 연구는 수산물 중 에톡시퀸 정량시험법을 확립하여 국내 생산 및 수입 양식 수산물에 대한 잔류할 수 있는 동물용의약품인 에톡시퀸에 대한 안전관리 강화기반을 위해 마련되었다. LC-MS/MS를 이용하여 신속하고 효과적으로 정량성 및 정밀성을 확보하였으며, 확립된 시험법의 선택성, 정량한계 및 회수율에 대한 검증을 통하여 에톡시퀸 시험법으로서의 유효성을 확인하였다. 표준용액을 정량한계를 포함한 농도에 따라 검량선을 작성한 결과 $r^2$> 0.99 이상의 직선성을 확인하였으며, 산성용매로 추출 후 MCX 카트리지를 이용해 정제하였다. 본 실험에서의 검출한계는 0.001 mg/kg, 정량한계는 0.01 mg/kg 수준이었고, 평균 회수율은 81.3~107%이었다. 또한, 분석오차는 10% 이하로 정확성 및 재현성이 우수하였으며, CODEX 가이드라인 규정에 만족하는 수준이었다. 따라서, 개발된 시험법은 안전한 국내유통 수산물과 국민보건을 위해 지속적인 잔류실태조사에 활용되고, 수산물 중 잔류동물용의약품의 안전관리에 기여할 것으로 판단된다.

• 농약과학회지
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• 제7권4호
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• pp.271-279
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• 2003

IAP-3006 원제(지베렐린산)의 SD계 랫드에 대한 아급성 경구 독성시험을 위하여 랫드에 1,000, 10,000과 15,000 ppm의 시험물질을 분말사료에 혼입하는 방법으로 주 5일, 90일간 경구 투여하여 그 독성과 안전성을 조사하였다. 전 시험기간 동안 모든 시험군의 동물에서 어떠한 임상 증상과 사망동물은 관찰되지 않았으며, 또한 체중변화, 사료 음수섭취량, 안과학적 검사, 뇨 검사 및 부검소견에서도 유의성 있는 변화는 보이지 않았다. 비록 혈액학적 검사, 혈액생화학적 검사 및 장기중량에서 유의성 있는 변화를 보였으나 모두 정상 범위에서의 변화이고 용량 의존적으로 나타나지 않았으며, 병리학적 소견에 있어서도 대조군과 비교하여 특이하게 다른 병변은 관찰되지 않았다. 이상의 결과로부터 IAP-3006 원제는 최고 투여용량인 15,000 ppm 에서도 유의할 만한 독성이 유발되지 않았으므로 안전한 것으로 판단되었으며, 무해용량은 15,000 ppm 이상으로 추정되었다.

• 한국산업보건학회지
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• 제16권3호
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• pp.233-244
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• 2006

Of many volatile organic detergents for metals, benzine(CAS No. 8030-30-6), of which the toxicity has not yet been proven, has been used as an alternative of the halide compounds in the consideration of toxic effects, global warming and the destruction of ozone layer. In order to evaluate the effects of the benzine on human body by investigating the subchronic inhalation toxicity, to obtain the basic data for establishing the criteria of exposure in working environments and to classify the hazardousness in compliance with the Industrial Safety and Health Act by evaluating the hazardousness, repeated inhalation exposure test was carried with SD rats. The rats were grouped by 10 females and males each. The repetitive inhalation exposures were carried out at 4 levels of concentration of 0 ppm, 60 ppm, 300 ppm, and 1,500 ppm, for 6 hours a day, 5 days a week, for 13 weeks. The results are described hereunder. 1. No death of the animals of the exposed and controlled groups in the test period. Not any specific clinical symptoms, change in feed intake quantity, abnormality in eye test, or change in activity were observed. 2. In the 300 ppm and 1,500 ppm groups, weight reduction in the female groups and weight increase of liver and kidney in the male groups compared with control group were observed with statistical significance(p<0.05). 3. In the blood test, the HCT increased in the male 300 ppm group and the number of hematocyte increased, MCV and MCH decreased in the male 1,500 ppm group. In the female 1,500 ppm group, the HB decreased and the distribution width of the hematocyte particle size increased. In the blood biochemistry test, the TP in the male 1,500 ppm group and the LDH in the female 1,500 ppm group were increased with statistical significance(p<0.05). 4. Under the test conditions of the present study with SD rats, the NOEL was evaluated to be from 60 ppm to 300 ppm for both male and female groups. By extrapolation, the NOEL for human who work 8 hours a day was evaluated to be from 128 ppm to 640 ppm 5. Since the NOEL evaluated in this study do not exceed 60ppm(0.184 mg/L) the test material does not belong to the classification of the hazardous substance "NOEL${\leq}$0.5mg/L/6hr/90day(rat), for continuous inhalation of 6hours a day for 90 days" nor to the basic hazardous chemical substance class 1(0.2 mg/L/6hr/90day(rat) defined by the GHS which is a criteria of classification and identification of chemical compounds. However, considering the boiling point($30-204^{\circ}C$), flashing point($-40^{\circ}C$), vapor pressure(40 mmHg), and the inflammable range(1.0 - 6.0 %), sufficient care should be taken for handling in the safety aspects including fire or explosion.

• 한국산업보건학회지
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• 제17권3호
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• pp.224-234
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• 2007

This study aimed to examine the harmful effects of Mn and Fe, which may be generated as dust or fume in the industrial sites, on the body and genital organs by their inhalation. It is intended to find the characteristics and differences of the hazardousness by inhaling a single and the mixed materials of Mn and Fe. Male F344 rats were divided into the control group and 3 exposed groups on the basis of the test material compound (Mn $1.5mg/m^3$, Mn 1.5 and Fe $3.0mg/m^3$, Fe $3.0mg/m^3$). The 4 groups were divided into 4 subgroups again on the basis of the exposure period (4 and 13 weeks) and the recovery period (4 and 13 weeks). The exposure condition was 6 hours a day, 5 days a week for the whole body. Clinical tests including changes in weight and feed rate, blood biochemical test, motility change, changes in the number and the amount of spermatozoon (sperm count), daily sperm production (DSP), deformity test of spermatozoon and changes in the accumulation of Mn and Fe in blood and internal organs were performed. Motility was reduced by Mn exposure. Especially, the effect of Mn was exposure period responsible. By mixing with Fe, no significant change in motility Mn and Fe accumulation in organs was observed. Sperm count and daily sperm production (DSP) were decreased by Mn. Additional effect like the reduction of sperm count and DSP, and delayed restoration of sperm count and DSP during the recovery period were observed in the mixed exposure group. These results indicate that Mn and Fe may affect the motility reduced and has male reproductive toxicity. Mixed exposure of Mn and Fe lead to synergic effects on the male reproductive toxicity.