• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.710-714
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• 1999

In veterinary medicine amitraz has been used as an insecticide to eliminate mites, lice, and ticks in dogs, cats, goats, swine and cattle. We performed the experiment on bradycardiac effect of arnitraz in rabbits. Under anesthetized with urethane (1g/kg, 25% w/v, SC), the femoral artery was cannulated by a polyvinyl tube which was connected with pressure transducer for continuous measurement of heart rate. Amitraz (0.5-2.5mg/kg, IV) reduced the heart rate in a dose-dependent manner. Pretreatment of yohimbine (2.0mg/kg) or atropine (2.0mg/kg and 4.0mg/kg) affected the response of amitraz but pretreatment of prazosin (0.5mg/kg) or propranolol (1.0mg/kg) did not. Moreover, the effect of amitraz was blocked by vagotomy. The result of our experiment suggest that amitraz may reduce the heart rate by increasing acetylcholine through activating vagal nerves and ${\alpha}_2$-adrenoceptors could be involved in activating vagal nerves.

• 한국항공운항학회:학술대회논문집
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• 2015.11a
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• pp.224-230
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• 2015

항공기 엔진 체계의 신뢰성과 안전성을 분석하는 것은 RAM 분석이라고 한다. RAM은 제작자가 개발한 시스템의 지속가능성 혹은 그 체계의 수명주기비용(Lice Cycle Cost)에 중대한 영향을 줄 수 있는 시스템 설계특성을 의미한다. 또한 RAM은 시스템이 개발될 당시에 의도된 임무를 수행할 수 있는 능력 혹은 임수수행을 성공할 수 있도록 담보하는 중요한 역할을 한다. RAM은 1970년대 이후 미국 군수분야에서는 군수지원성분석(LSA, Logistic Support Analysis) 과 밀접히 연계되어 활용되어 왔으며, RAM과 LSA를 통합하여 종합군수지원체계(ILS, Integrated Logistics Support)라고 부른다. 본 연구에서는 항공기 엔진에 대한 신뢰성 분석에 Weibull 분포를 활용하였다. Weibull 분포는 2개의 변수 적용에서 다음과 같이 정의된다. 변수가 그 계의 어떤 값을 나타내느냐에 따라 분포도 곡선의 특성 의미는 변수에 의존된다. 예를 들어 시험성적, 사회적 특성을 표현하는 인지도, 산업 제품의 고장이나 결함을 나타내는 고장관련 모수(변수) 등에 따라 그 특징을 나타내게 된다. 항공기 엔진의 신뢰성 분석을 통해 항공기 엔진의 수명 판단이 가능해졌으며 임무 불가능 수준의 In-Flight Shut-Down 비율이 현격히 감소됨을 확인할 수 있었다.

• The Korean Journal of Ecology
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• v.11 no.1
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• pp.17-28
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• 1988

Five hundrad and eight rats were caught in Shiheung-dong and Mt. Kwan-ak from 1986 to 1987 in this survey. Ectoparasites were got from these rats and classified. The results were as follows: 9,191 mites (16 genera, 30 species), 408 fleas (4 genera, 4 species), and 521 lice (3 genera, 5 species) were observed in this survey. In the residential area, Rattus norvesicus(71.74%) was dominant species and in Mt. Kwan-ak Apodemus agrarius(93.62%). In these areas, the mites belonging to suborder Mesostigmata were dominant (Laelaps nuttli, 52.61%; Ornithonyssus bacoti, 36.05%). In Mt. Kwan-ak, family Frombiculidae belonging to suborder Prostigmata were dominant (Leptotromibidium orientalis, 31.04%; Leptotrombidium palpalis, 30.00%). In this way, it was discovered that the difference between the two regions in dominant species was noticeable. As for the hosts parasitized by mites, L. nuttalli in R. norvegicus (54.85%), L. nuttalli in R. rattus (32.90%), and L. orientalis in A. agrarius (31.27%) were dominant species, respectively. In the mites parasitizing on A. agrarius in each altitude, the species were more varied as the region was lower and the dominant species were more concentrated as it was higher.

• Animal cells and systems
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• v.1 no.2
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• pp.323-328
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• 1997

We have previously shown that chick muscle extracts contained at least 10 different ubiquitin C-terminal hydrolases (UCHs). In the present studies, one of the enzymes, called UCH-9, was purified by conventional chromatographic procedures using $^{125}l$-labeled ubiquitin-${\alpha}$NH-MHISPPEPESEEEEE HYC (Ub-PESTc) as a substrate. The purified enzyme behaved as a 27-kDa protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. It was maximally active at pHs between 7 and 8.5, but showed little or no activity at pH below 6 and above 10. Lice other UCHs, its activity was strongly inhibited by sulfhydryl blocking reagents, such as iodoacetamide, and by Ub-aldehyde. In addition to Ub-PESTc, UCH-9 hydrolyzed Ub-aNH-protein extensions, including Ub-${\alpha}NH$-carboxyl extension protein of 80 amino acids and Ubo-${\alpha}NH$-dihydrofolate reductase. However, this enzyme was not capable of generating free Ub from mono-Ub-${\varepsilon}NH$-protein conjugates and from branched poly-Ub chains that are ligated to proteins through ${\varepsilon}NH$-isopeptide bonds. This enzyme neither could hydrolyze poly-His-tagged di-Ub. These results suggest that UCH-9 may play an important role in production of free Ub and ribosomal proteins from their conjugates.

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.409-416
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• 2017

The high prevalence of pediculosis capitis, commonly known as head lice (Pediculus humanus capitis) infestation, has led to the preparation of a community-based pediculicidal ointment, which is made of common household items and the extract of Tinospora crispa stem. The present study aimed to evaluate the safety, efficacy, and physicochemical characteristics of the T. crispa pediculicidal ointment. The physicochemical properties of the ointment were characterized, and safety was determined using acute dermal irritation test (OECD 404), while the efficacy was assessed using an in vitro pediculicidal assay. Furthermore, the chemical compounds present in T. crispa were identified using liquid-liquid extraction followed by ultra-performance liquid chromatography quadruple time-of-flight mass spectrometric (UPLC-qTOF/MS) analysis. The community-based ointment formulation was light yellow in color, homogeneous, smooth, with distinct aromatic odor and pH of $6.92{\pm}0.09$. It has spreadability value of $15.04{\pm}0.98g{\cdot}cm/sec$ and has thixotropic behavior. It was also found to be non-irritant, with a primary irritation index value of 0.15. Moreover, it was comparable to the pediculicidal activity of the positive control $Kwell^{(R)}$, a commercially available 1% permethrin shampoo (P>0.05), and was significantly different to the activity of the negative control ointment, a mixture of palm oil and candle wax (P<0.05). These findings suggested that the community-based T. crispa pediculicidal ointment is safe and effective, having acceptable physicochemical characteristics. Its activity can be attributed to the presence of compounds moupinamide and physalin I.

• Journal of fish pathology
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• v.32 no.2
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• pp.91-96
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• 2019

Rainbow trout (Oncorhynchus mykiss) were treated with ultrasonic (40kHz) and microbubble. The organic serum components, glucose were decreased compared to control at microbubble single treatment (M) and ultrasonic treatment (UL), but glucose concentrations in fish serum of all experimental groups analyzed in this study were also within the normal range. The organic serum components, cholesterol and total protein were no significant change by ultrasonic and microbubble treatment. There were no significant changes in the lysozyme activity on ultrasonic and microbubble treatment. Serum bactericidal activity decreased on ultrasonic single treatment (UL) compared to the control (P<0.05), but the numbers of bacterial colonies were significantly lower than those in the negative (PBS). The results of this study indicate that ultrasonic and microbubble treatment did not have a critical effect on the serum composition and innate immunity of O. mykiss, and that it is a way to do not significant stress on the fish body as a countermeasure against sea lice.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.271-276
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• 1989

The prevalence of head louse (Pediculus hamanus var. capitis) infestation in preschool and school children in 9 urban and 8 rural areas of Korea, was investigated. Of 11,865 children who were examined for head lice and nits, 2,900 (24.4%) pere found infested. The over-all infestation rate of rural children, 58.9%, was higher than that of urban children, 14.4%. There also existed significant differences in the infestation rate among various regions of urban as well as rural areas. Females were more infested than males. But there was no difference in infestation rate in either sex of Preschool alee. The infestation rate increased gradually from the age of 6, reached a plateau between 9∼12 years of age and thereafter slowly decreased. The infestation rate of an orphanage children was higher than that of general childhood population. Health education and mass-delousing attempt are urgently required to lower such a high prevalence of head louse infestation in Korea.

• YAKHAK HOEJI
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• v.45 no.6
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• pp.694-700
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• 2001

Synthetic pyrethroids are analysis of a natural chemical moiety, pyrethrin derived from the pyrethrum plant Chrysanthemum. The natural pyrethrin structure has been modified to be highly lipophilic and photostable, creating an effective pesticide and resulting in an increased presence in the environment. Worldwide, they are commonly used insecticides against ticks, mites, mosquitoes, and as treatment for human head lice and scabies. Therefore, human exposure to their compounds in extensive. Several studies on the effects of pyrethroids on thyroid hormone regulation, estrogen and androgen function have been reported and yet little has been done try assess their potential hormonal activities. Among humans, a pyrethroid compound was suggested to be the causal agent for gynecomastia in a group of Haitian men. The reports suggest that some pyrethroid compounds are capable of disrupting endocrine function. Therefore, we examined estrogenic/antiestrogenic potential of three pyrethroid insecticides, that is permethrin, allethrin and fenvalerate in human breast cancer cell and action mechanism mediated by the estrogen receptor. Fenvalerate showed weak estrogenic activity but aallethrin and permethrin showed no effect. In combination with high levels (10$^{-10}$ M, 10$^{-11}$ M) of 17$\beta$-estradiol and three synthetic pyrethroids inhibited cert proliferations in MCF7-BUS cell by 17$\beta$-estradiol. Whereas, fenvalerate increased cell proliferative activity at lower level of estradiol (10$^{-12}$ M, 10$^{-13}$ M). The relative affinities to the estrogen receptor were observed by allethrin and permethrin treatment, but not by fenvalerate. These results indicated that some of pyrethroid insecticides may modulate estrogen functions in human breast cancer cell. The action mechanisms of estrogen receptor mediated antiestrogenicity by allethrin and permethrin were postulated.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.53-59
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• 2023

Head louse infestation is a significant public health problem across the world, particularly among preschool and primary schoolchildren. This study investigated the trends of head louse infestation in the Republic of Korea over a 9-year period (2011-2019), targeting primary schoolchildren in 3 areas of Seoul, 4 other large cities, and 9 provinces. A survey was administered annually by the health staff of each regional office (n= 16) of the Korea Association of Health Promotion (KAHP). The branch offices of KAHP examined a total of 51,508 primary schoolchildren, comprising 26,532 boys and 24,976 girls. Over the 9-year survey, a total of 1,107 (2.1%) schoolchildren tested positive for adults and/or nits of Pediculus humanus capitis. The prevalence was 2.8% (133/4,727) in 2011-2012 and gradually decreased to 0.8% (49/6,461) in 2019 (P< 0.05). Head lice were found more frequently in girls (3.0%; 746/24,976) than in boys (1.4%; 361/26,532) (P< 0.05). In terms of geographic localities, the highest infestation rate, 4.7% (average prevalence over 9 years), was observed in southern Seoul (Gangnam branch of KAHP), whereas the lowest infestation rate, 0.7%, was seen in Gyeongsang (north and south provinces) and western Seoul. Although the prevalence decreased significantly during the 9-year period, head louse infestation remains a health and hygiene issue among primary schoolchildren in the Republic of Korea. Regular surveys along with health education are needed to further improve children's hair hygiene.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.6
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• pp.17-27
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• 2014

Wild boars are one of the major wild life animals of which the number has increased a lot because there has been any predator and/or competitor in the Korean ecosystem. The increase of their number was a cause damaging crops in farm lands during the growing season in South Korea. This study was done to recognize the spatial pattern of farm lands damaged by wild boars. Totally 2,342 farms were known damaged by wild boars in 2012, and used to statistically analyze the perspectives of the farm land damages by wild boars in ArcMap v. 9.3. Damages by wild boars frequently happened in the western part of Gyeongnam Province including Jinju city, Tongyoung city and Namhae county. Most farm lands damaged were located nearby large mountains in this area. It might cause the number of wild boars increased in this area, which could finally stimulate the increase of farm land damaged by the species. Farm land damages by wild boars were also coincident with the preference of wild boars on their food. They preferred crops (e.g., sweet potato and corn) in uplands and rice paddies and orchards. The reason of their preference on rice, upland crops and fruits was related to the efficiency of their getting much more energy in a unit area. Another reason for the species to come into a rice paddy would be that they enjoy mud bath in there for scraping off parasites such as ticks and lice. Wild boars were seemed much overcrowded during the period from July to October when most of crops and fruits get ripen. About three-quarters of total farm land damages happened in this period. This analysis also said that 1,915 fields (81.8% of total targets) appeared within the 100-meter buffer from boundaries of mountain areas. This meant that wild boars were more sensitive to the anthropogenic land uses than we expected. They seemed to conservatively try their feeding activities in farm lands with paying attention to the human activity.