• Title/Summary/Keyword: repeated exposure

검색결과 251건 처리시간 0.024초

양식 어류와 이들 난에 대한 항곰팡이성 약물들의 효과 비교 (Comparative Efficacy of Antifungal Agents for Aquaculture Fish and their Eggs)

  • 지보영;이덕찬
    • 한국수산과학회지
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    • 제42권1호
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    • pp.34-40
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    • 2009
  • In fresh water fish hatcheries and farms, Saprolegniales often cause serious mortality to the fish and their eggs. Malachite green is an effective antifungal agent, but is carcinogenic to fish and humans. Alternative antifungal agents are needed. Presently, we tested various concentrations of MBT-01108 (Opuntia ficus-indica extracts) alone and in combination with bronopol, formalin and sodium chloride (MBT-01108 mixture) on in vitro mycelial growth and in vivo remediation of adult eel, Anguilla japonica, infected with Saprolegnia sp. and fertilized eggs of chum salmon, Oncorhynchus keta, to evaluate the compounds' antifungal efficacy on eyed-egg and hatching rates. MBT-Oll08 mixtures incorporating bronopol and formalin at respective concentrations of 50 and 30 parts per million (ppm), and 100 and 20 ppm were most effective in controlling Saprolegnia in vitro and in vivo (P<0.05). Repeated daily exposures to 50 ppm and 100 ppm MBT-01108 were more effective than exposure every 2-3 days post-fertilization for the inhibition of Saprolegnia infection of rainbow trout, Oncorhynchus mykiss eggs as compared with control (0 ppm).

국내소음지도 표준화를 위한 현황 평가 (Evaluation of Present Status for the Korean Noise Map Standardization)

  • 박인선;박상규
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.517-520
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    • 2005
  • Noise mapping covers the whole mapping process from the collection of raw data, storage and retrieval of the data for computation/modeling, to the presentation of information related to outdoor sound levels, sound exposure, noise effects or numbers of affected person. This presentation can be in either a graphical or numerical form. In Europe, the Directive 2002/49/EC of the European Parliament and of the Council relating to the assessment and management of environmental noise is now being implemented in the EU Member States. Here, The first maps for major areas are required by mid 2007, and action plans required one year later. These activities are repeated at five yearly intervals and all defined areas are incorporated in the following round of deadlines starting in 2012. The above are minimum requirements and some countries are expected to go further and faster. In this study, present status of domestic and international noise maps has been introduced to implemente the Korean noise map standard. This will help to get more convenient and, more fair result, and produce correct map at domestic level.

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1,1-Dichloro-1-fluoroethane Induces Micronuclei in Bone Marrow Cells by Repeated Inhalation Exposure but not by the Single Peritoneal Injection

  • Maeng, Seung-Hee;Kim, Hyun-Young;Lim, Cheol-Hong;Lee, Jong-Yoon;Lee, Yong-Mook;Chung, Ho-Keun;Chung, Hai-Won;Yu, Il-Je
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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    • pp.150-150
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    • 2001
  • To investigate the genotoxic effect of 1, 1-dichloro-1-fluoroethane, which was widely used as a cleaning solvent at the electronic part industry, the micronucleus frequencies were recorded by examining polychromatic erythrocytes in bone marrows of the rodents exposed to it with different routes.(omitted)

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An Experimental Model for Induction of Lung Cancer in Rats by Chlamydia Pneumoniae

  • Chu, De-Jie;Guo, Shui-Gen;Pan, Chun-Feng;Wang, Jing;Du, Yong;Lu, Xu-Feng;Yu, Zhu-Yuan
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2819-2822
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    • 2012
  • Objective: To assess induction effects of Chlamydia pneumoniae (Cpn) on lung cancer in rats. Methods: A lung cancer animal model was developed through repeated intratracheal injection of Cpn (TW-183) into the lungs of rats, with or without exposure to benzo(a)pyrene (Bp). Cpn antibodies (Cpn-IgA, -IgG, and -IgM) in serum were measured by microimmunofluorescence. Cpn-DNA or Cpn-Ag of rat lung cancer was detected through polymerase chain reaction or enzyme-linked immunosorbent assay. Results: The prevalence of Cpn infection was 72.9% (35/48) in the Cpn group and 76.7% (33/43) in the Cpn plus benzo(a)pyrene (Bp) group, with incidences of lung carcinomas in the two groups of 14.6% (7/48) and 44.2% (19/43), respectively (P-values 0.001 and <0.000 compared with normal controls). Conclusions: A rat model of lung carcinoma induced by Cpn infection was successfully established in the laboratory for future studies on the treatment, prevention, and mechanisms of the disease.

자동차 페인트 도장공에서 발생한 과민성 폐렴 1예 (A Case of Hypersensitivity Pneumonitis in an Automobile Paint Sprayer)

  • 오미나;조명진;백훈기;조기성;강지훈;김영;곽진영
    • Tuberculosis and Respiratory Diseases
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    • 제65권6호
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    • pp.541-545
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    • 2008
  • 페인트, 가구 도장제 등에 포함된 Isocyanate는 직업성 천식의 흔한 원인물질로 알려져 있고, 과민성 폐렴을 일으키기도 한다. 저자들은 6개월간 자동차 공장 페인트 도장공으로 일한 중국인 노동자에서 isocyanate에 의한 것으로 추정되는 과민성 폐렴 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

Prenatal Stress Induces Skeletal Malformations in Mouse Embryos

  • Kim, Jongsoo;Yun, Hyo Jung;Lee, Ji-Yeon;Kim, Myoung Hee
    • 대한의생명과학회지
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    • 제21권1호
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    • pp.15-22
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    • 2015
  • Dexamethasone, a synthetic glucocorticoid (GC), is clinically administered to woman at risk for premature labor to induce fetal lung maturation. However, exposure to repeated or excess GCs leads to intrauterine growth restriction (IUGR) and subsequently increases risk of psychiatric and cardio-metabolic diseases in later life through fetal programming mechanisms. GCs are key mediators of stress responses, therefore, maternal nutrient restriction or psychological stress during pregnancy also causes negative impacts on birth and neurodevelopment outcome of fetuses, and other congenital defects, such as craniofacial and skeletal abnormalities. In this study, to examine the effect of prenatal stress on fetal skeletal development, dexamethasone (1 mg/kg [DEX1] or 10 mg/kg [DEX10] maternal body weight per day) was administered intraperitoneally at gestational day 7.5~9.5 and the skeletons were prepared from embryos at day 18.5. Seven out of eighteen (39%) embryos treated with DEX10 showed axial skeletal abnormalities in either the T13 or L1 vertebrae. In addition, examination of the sternum revealed that xiphoid process, the protrusive triangular part of the lower end of the sternum, was bent more outward or inward in DEX group embryos. In conclusion, our findings suggest a possible link to the understanding of the effect of uterine environment to the fetal skeletal features.

Evidence for adverse effect of perinatal glucocorticoid use on the developing brain

  • Chang, Young Pyo
    • Clinical and Experimental Pediatrics
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    • 제57권3호
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    • pp.101-109
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    • 2014
  • The use of glucocorticoids (GCs) in the perinatal period is suspected of being associated with adverse effects on long-term neurodevelopmental outcomes for preterm infants. Repeated administration of antenatal GCs to mothers at risk of preterm birth may adversely affect fetal growth and head circumference. Fetal exposure to excess GCs during critical periods of brain development may profoundly modify the limbic system (primarily the hippocampus), resulting in long-term effects on cognition, behavior, memory, co-ordination of the autonomic nervous system, and regulation of the endocrine system later in adult life. Postnatal GC treatment for chronic lung disease in premature infants, particularly involving the use of dexamethasone, has been shown to induce neurodevelopmental impairment and increases the risk of cerebral palsy. In contrast to studies involving postnatal dexamethasone, long-term follow-up studies for hydrocortisone therapy have not revealed adverse effects on neurodevelopmental outcomes. In experimental studies on animals, GCs has been shown to impair neurogenesis, and induce neuronal apoptosis in the immature brains of newborn animals. A recent study has demonstrated that dexamethasone-induced hypomyelination may result from the apoptotic degeneration of oligodendrocyte progenitors in the immature brain. Thus, based on clinical and experimental studies, there is enough evidence to advice caution regarding the use of GCs in the perinatal period; and moreover, the potential long-term effects of GCs on brain development need to be determined.

골절 수술용 엑스레이 투과 원격조종 스튜어트 플랫폼의 설계 및 제어 (Design and Control of X-ray Permeable Teleoperated Stewart Platform for Fracture Surgery)

  • 유병준;김혜미;이성학;임순호;박태곤;이치범
    • 한국생산제조학회지
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    • 제24권6호
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    • pp.660-666
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    • 2015
  • To avoid radiation exposure from repeated x-rays taken during orthopedic surgery, an x-ray permeable teleoperated Stewart platform for orthopedic fracture surgery was developed. This system is composed of a user interface device and a teleoperated operational robot, both of which use a Stewart platform mechanism. The links of the operational robot are made from an x-ray permeable material, polycarbonate, to minimize the interference. The forward and inverse kinematics algorithm applied and the structural reliability were both verified through an analysis using commercial engineering software. To monitor the operating status in real time and stop the device during an emergency, a monitoring software was developed. The performance of the x-ray permeable teleoperated Steward platform was validated experimentally.

MICRONUCLEI INDUCTION BY REPEATED INHALATION EXPOSURE TO THE 1,1-DICHLORO-1-FLUOROETHANE BUT NOT BY THE SINGLE PERITONEAL INJECTION

  • Maeng, Seung-Hee;Chung, Hai-Won;Kim, Hyun-Young;Lim, Cheol-Hong;Lee, Jong-Yoon;Chung, Yong-Hyun;Lee, Yong-Mook;Chung, Ho-Keun;Yu, Il-Je
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2001년도 International Symposium on Dietary and Medicinal Antimutgens and Anticarcinogens
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    • pp.179-179
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    • 2001
  • To investigate the genotoxic effect of 1, 1-dichloro-1-fluoroethane which was widely used as a cleaning solvent at the electronic part industry, the micronucleus frequencies were recorded by examining polychromatic erythrocytes in bone marrows of single i.p. injected mice at high doses and of the repeatedly inhaled rats for 13 weeks at relatively low concentrations.(omitted)

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일부 주택에서 집먼지 진드기 알러젠 조사 (A Survey of House Dust Mite Allergen Contamination in House)

  • 손종렬;윤승욱;권보연
    • 한국대기환경학회지
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    • 제22권5호
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    • pp.719-723
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    • 2006
  • House dust mite was the most important cause of allergic asthma and rhinitis. More than 70% of Korean children and about 50% of adult with respiratory allergy were sensitive to house dust mite. This experiment was indoor environment in house and house dust mite existence inquiry. From 23rd December 2005 to 28th February 2006, dust samples were collected from the bedclothes by a vacuum cleaner and air sampler And the levels of Der f1 and Der p1 were determined by ELISA((Enzyme-Linked Immunosorbent Assay). The results were as follows : 1 The dust mites allergy contaminations of bedclothes in house were higher than international standards(2000 ng/g). 2. In type of dust mite, the Korean house the almost have the D. farinae other than D. pteronyeeinus of mite. 3. The Der f1 and Der p1 levels per gram of dust from the bedclothes were 2074.99 ng on average, but they did not exist in air. The concentrations of house dust mite were significantly high in the bedclothes. This results suggest that the bedclothes have enough concentrations of dust mites to develop the sensitization. The control of indoor environment should be emphasized to prevent the sensitization by the repeated exposure to dust mite.