• Fisheries and Aquatic Sciences
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• 제20권3호
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• pp.4.1-4.6
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• 2017

Juvenile Anoplopoma fimbria (mean length $16.8{\pm}2.2cm$, and mean weight $72.8{\pm}5.4g$) were exposed for 2 months with different levels of ammonia (0, 0.25, 0.50, 0.75, 1.00, and 1.25 mg/L). Growth performances such as daily length gain, daily weight gain, condition factor, and hepatosomatic index were significantly decreased by ammonia exposure. Hematological parameters such as red blood cell (RBC) count, hematocrit, and hemoglobin were also significantly decreased. In plasma inorganic components, calcium and magnesium were significantly decreased by ammonia exposure. In plasma organic components, there was no alteration in cholesterol and total protein. In enzyme plasma components, glutamic oxalate transaminase (GOT) and glutamic pyruvate transaminase (GPT) were significantly increased. The results of this study indicated that ammonia exposure can induce significant growth reduction and blood biochemistry alterations of A. fimbria.

• 공업화학
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• 제1권2호
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• pp.161-167
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• 1990

Methylphenyldichlorosilane을 중합시켜 poly(methylphenyl)silane(PMPS)을 합성하고 이를 photoresist로 이용하는데 있어서 화상형상특성을 설명하기 위하여 노광에 의한 광학계수 X, Y, Z를 측정하였다. 광학계수 X, Y, Z는 PMPS 필름에 광조사를 시킨 다음 투과도를 측정하여 구하였으며, 계수 Z는 광조사 시간에 따른 투과도의 초기 기울기로 부터 구하였다. 이들 계수로 부터 PMPS에 각종 증감제를 첨가하여 제조한 필름에 광조사를 시켜 광조사특성을 이론적으로 구하고 이를 잔막수득율을 측정한 결과 Z치와 잔막수득율은 parallel한 관계가 있었다.

• 한국정밀공학회지
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• 제24권9호
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• pp.37-43
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• 2007

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.52-57
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• 2004

해체부지 선량평가 모델의 주요 핵종에 대한 key parameter를 분석하기 위하여 민감도 분석을 수행하였다. 본 연구에서 민감도 분석을 수행하기 위한 주요 가정 사항으로서 피폭시나리오는 가장 보수적인 resident farmer를 그리고 방사성핵종의 오염 정도는 0.037 Bq/g로 하였다. 분석결과, 감마 방출 핵종인 Cs-137과 Co-60의 경우에는 오염지역의 면적과 거주관련 변수(외부감마차폐인자와 실내 거주시간분율), C-14 핵종의 경우에는 환경변수와 불포화층의 수문학적 변수가, Sr-90 핵종의 경우에는 오염지역의 토양 밀도가 선량에 미치는 영향이 큰 parameter로 확인되었다.

• Archives of Pharmacal Research
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• 제9권3호
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• pp.175-181
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• 1986

Four technical grade organophosphate pesticides (Fenitrothion, Fenthion, Dizninon and EPN) were investigated for their effects on the murine immune function. Among the immunotoxicological assay parameters of NIEHS, humoral immune parameter and pathotoxicological indicators were examined in this study. Subchronic exposure of rodents to these pesticides resulted in marked suppression of humoral immune function and moderate histological changes of lymphoid organ any significant alterations of clinical status.

• 한국식품영양과학회지
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• 제28권6호
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• pp.1349-1354
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• 1999

This study was carried out to investigate the protective effect of Korean red ginseng water extract (KRG WE) on clinical chemical parameters in male guinea pigs acutely exposed to 2,3,7,8 tetrachlorodibenzo p dioxin(TCDD). Forty male guinea pigs(200 $\pm$20g) were divided into 4 groups. Normal controls(group 1) received vehicle and saline; group 2(single TCDD treated) received TCDD(5 g/kg, single dose) intraperitoneally; group 3 received KRG WE(200mg/kg, i.p.) for 2 weeks from 1 week before TCDD exposure; group 4 received KRG WE for 1 week since the day of TCDD exposure. Increase in body weight was retarded greatly by TCDD exposure. Body weight of animals in group 2 was significantly decreased starting 2 days after TCDD exposure. However, body weight of animals in group 3 increased throughout the experimental period, although the increasing rate was slower than that of group 1. Decrease in body weight was not observed during the experimental period in group 4. Increases in blood glucose, amylase, lipase, total cholesterol, triglyceride, GOT, GPT, and LDH levels by TCDD intoxication were significantly attenuated by the KRG WE treatment(p<0.05). These results provide a strong evidence that Korean red ginseng might be a useful protective agent against TCDD, an endocrine disruptor.

• Imaging Science in Dentistry
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• 제35권2호
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• pp.87-90
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• 2005

Purpose : The purpose of this study was to investigate variability of doses with same exposure parameters and evaluate radiographic density according to the variability of doses. Materials and methods Twenty-eight MAX-GLS (Shinhung Co, Seoul, Korea), twenty-one D-60-5 (DongSeo Med, Seoul, Korea), and eleven REX-601 (Yoshida Dental MFG, Tokyo, Japan) dental x-ray machines were selected for this study Surface doses were measured under selected combinations of tube voltage, tube current, exposure time, and constant distance 42 cm from the focal spot to the surface of the Multi-O-meter (Unfors Instruments, Billdal, Sweden). Radiographic densities were measured on the films at maximum, minimum and mean surface doses of each brand of x-ray units. Results With MAX-GLS, the maximum surface doses were thirteen to fourteen times as much as the minimum surface doses. With D-60-S, the maximum surface doses were three to eight times as much as the minimum surface doses. With REX-601, the maximum surface doses were six to ten times as much as the minimum surface doses. The differences in radiographic densities among maximum, mean, and minimum doses were significant (p<0.01). Conclusion : The surface exposure doses of each x-ray machine at the same exposure parameters were different within the same manufacturer's machines.

• The Korean Journal of Physiology and Pharmacology
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• 제23권6호
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• pp.467-474
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• 2019

Exposure to lead during pregnancy is a risk factor for the development of psychiatric disorders in the offspring. In this study, we investigated whether exposure to low levels of lead acetate (0.2%) in drinking water during pregnancy and lactation causes behavioral impairment and affects the expression of proteins associated with neurodevelopment. Lead exposure altered several parameters in rat offspring compared with those unexposed in open-field, social interaction, and pre-pulse inhibition tests. These parameters were restored to normal levels after clozapine treatment. Western blot and immunohistochemical analyses of the hippocampus revealed that several neurodevelopmental proteins were downregulated in lead-exposed rats. The expression was normalized after clozapine treatment (5 mg/kg/day, postnatal day 35-56). These findings demonstrate that downregulation of several proteins in lead-exposed rats affected subsequent behavioral changes. Our results suggest that lead exposure in early life may induce psychiatric disorders and treatment with antipsychotics such as clozapine may reduce their incidence.

• 한국의학물리학회지:의학물리
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• 제9권4호
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• pp.217-225
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• 1998

본 연구에서는 A청감보정 소음레벨과 폭로기간에 대한 소음유발 청력손실과 소음폭로 사이의 관계를 해석하였다. 연령과 소음폭로등 다양한 변수에 대하여 청력손실과 청감민감도 변화를 조사하였다. 연구결과 전체 청력손실은 음압의 시간적분에 의한 소음폭로 레벨에 비례하였다. 만약 소음폭로가 노인성 난청보다 크면 연령과 소음에 의해 발생하는 청력손실은 주된 원인이 소음에 의한 것임을 확인하였다. 과도한 소음은 일시적 청력손실의 원인이며, 폭로가 길어지거나 강력하면 영구적 청력손실의 원인이 될 수 있다. 소음유발 청력손실을 겪는 사람의 청력도는 4kHz 영역에서 청감민감도의 급격한 손실을 보여주며, 이 영역은 여러 형태의 산업소음으로 인해 가장 손상받기 쉬운 전형적인 주파수영역임을 확인하였다.

• Imaging Science in Dentistry
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• 제52권3호
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• pp.283-288
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• 2022

Purpose: This study was conducted to measure the radiation exposure and image quality of various cone-beam computed tomography (CBCT) machines under common clinical conditions and to analyze the correlation between them. Materials and Methods: Seven CBCT machines used frequently in clinical practice were selected. Because each machine has various sizes of fields of view (FOVs), 1 large FOV and 1 small FOV were selected for each machine. Radiation exposure was measured using a dose-area product (DAP) meter. The quality of the CBCT images was analyzed using 8 image quality parameters obtained using a dental volume tomography phantom. For statistical analysis, regression analysis using a generalized linear model was used. Results: Polymethyl-methacrylate (PMMA) noise and modulation transfer function (MTF) 10% showed statistically significant correlations with DAP values, presenting positive and negative correlations, respectively (P<0.05). Image quality parameters other than PMMA noise and MTF 10% did not demonstrate statistically significant correlations with DAP values. Conclusion: As radiation exposure and image quality are not proportionally related in clinically used equipment, it is necessary to evaluate and monitor radiation exposure and image quality separately.