• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.361-374
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• 2015

Endocirne disruptors (EDs) can cause fertility decrease, developmental disorder, and even cancer in animals. Until 90's, EDs were used in various synthetic products including paints, coatings, detergents, plastics, and plasticizers. Currently, in several countries, the production, trade and use of EDs or EDs-suspected chemicals have been regulated while activity to screen the alternatives for EDs including bisphenol-A, phthalate and nonylphenol is active. Although various toxicity test method was developed and applied for screening of alternatives, however, the safety of alternatives has been not fully demonstrated. Some alternatives have high structural similarity with existing EDs, raising the possible risk of endocrine disruption by alternatives. In an effort to develop the safe alternatives, we reviewed the effects of EDs such as bisphenol-A, phthalates, nonylphenol and their substituents. In addition, in-silico analysis for endocrine disrupting activities of some alternatives was presented.

• Development and Reproduction
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• v.6 no.1
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• pp.25-30
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• 2002

Endocrine disruptors have been reported to adversely affect reproduction and embryonic development in wild animals. One of the major abnormalities observed during early embryonic development is cellular fragmentation. In this study, we exposed mouse preimplantation embryos to PCB, BPA and DDT in vivo or in vitro. Embryos exposed to endocrine disrupter showed a variety of morphological abnormalities such as fragmentation, irregular blastomeres and cracked empty zonae pellucidae. To investigate the levels of gene expression related which genes contribute to apoptosis in preimplantation mouse embryos, we carried out the reverse transcription polymerase chain reaction to assess mRNA levels far apoptotic gene. Bcl-2, bad and bax expression levels were compared between control group and endocrine disrupter treated group. Expression level of bcl-2 gene tended to be lower in the treated group than control while expression levels of bad and bax genes were higher in the treated group. Results of this study may provide a useful tool for rapidly screening developmental toxicants in preimplantation embryos exposed to endocrine disruptors in vivo or in vitro.

• International journal of thyroidology
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• v.11 no.2
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• pp.88-91
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• 2018

After introducing tyrosine kinase inhibitors (TKIs) as promising treatments for radioactive iodine refractory advanced thyroid cancer patients, we more often meet patients with TKI-related hormone and electrolyte imbalances in clinics. Hypocalcemia associated with TKI is associated with an imbalance in calcium-vitamin D metabolism. TKI-related hypothyroidism is related to the metabolic rate of thyroid hormones. The two side effects usually occur in the early stages of TKI treatment, and if the imbalance is corrected appropriately, the effects are minor, but in severe cases, the TKI should be discontinued. The authors reported a case of severe hypocalcemia and thyroid dysfunction after TKI treatment. A 56-year-old man suffered from symptomatic hypocalcemia during TKI treatment, which was resolved after he stopped taking the TKI medication. Although calcium and vitamin D replacement have increased, hypocalcemia was recurred and TKI treatments have been permanently stopped due to serious weight loss in grade 3. After the interruption, his calcium levels normalized.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.3
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• pp.60-65
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• 2008

A typical louvered-fin oil cooler can be easily contaminated under dusty environment hence resulting in poor performance of a heat exchanger. Thus, in this study, a dust-proof oil cooler has been studied with a unique shape of a 3-dimensional wavy fin since non-louvered fins could have better performance under dusty environment compared to louvered fins. Recently, they have been introduced to commercial and constructional vehicles in Japan. At first numerical analysis has been done to optimize the angle of the wavy fin so that the oil cooler developed can satisfy the target performance. The wavy fin has been then made with roll-forming and roll-pitch stands, and a prototype of an oil cooler with the wavy fin has been finally built with brazing. The performance test showed that the heat release rate of the oil cooler was well beyond the target, 4.94kW and the air-side pressure drop was below the criterion, 0.19kPa. In addition, the results showed that the numerical prediction was effective enough to design the dust-proof oil cooler that satisfies the performance criteria.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.1-10
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• 2011

Amphibian population declines globally. Aquatic contamination by organic pollutants including endocrine disrupters has been suspected to the one of the reason for distinction of amphibia which has obligate aquatic life style during larval period. Amphibians have been widely accepted as animal model for the study of endocrine disruption in aquatic ecosystem at molecular as well as individual levels. There are increasing need for toxicological data in amphibians at multiple endpoints for management of contamination and development of safety guideline for important EDs in aquatic media. Alkylphenols have been widely used in agricultural, industrial, and housekeeping activities, contaminating the aquatic media and evoking endocrine disruption in aquatic animals. In this review, we summarized data concerning the endocrine disruption by alkylphenol organic pollutants on amphibians according to route, concentration, terms, and developmental stage of exposure together with mechanism of endocrine disruption.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.4
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• pp.126-132
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• 2009

Automotive heat exchangers use louver fins for their high efficiency. However, the efficiency can significantly drop for constructional vehicles or heavy equipments due to dust deposited on the louver fins with narrow slits. Thus it is necessary to develop new fins that lead to less fouling, so that a better performance can be achieved after exposure to a dusty environment over long period of time. New wavy fins were considered in the study and numerically analysed to compare with louver fins in the areas of air-side pressure drop, heat release rate, and particulate deposition. In addition, an experiment was done on the pressure drop and the particulate deposition. The results showed that the wavy fins would be a better choice for long-term use due to the excellent dust-proof performance in comparison to louver fins, in spite of the initial inferior performance of heat release.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.363-364
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• 2008

Localization algorithms are required for indoor sensor network applications. In this paper, we introduce an efficient algorithm for low complexity and high accuracy, termed multi-internal division localization(MID), which emphasizes simple refinement and low system-load for low-cost and low-rate wireless sensors. We inspect MID algorithm through MATLAB simulation.

• Journal of the Korean Orthopaedic Association
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• v.54 no.6
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• pp.567-573
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• 2019

Slipped capital femoral epiphysis (SCFE) is a rare disorder of the proximal femur in adolescents. The pathogenesis of SCFE is unclear, but it is believed to be the result of a mechanical insufficiency of the proximal femur physis. SCFE appears to caused by mechanical, endocrinal, and immunological abnormalities. Few cases have reported the SCFE associated with endocrine disorder in the domestic literature, particularly in patients over 20 years old. This paper reports two cases of SCFE associated with hypopituitarism in adults over 20 years old.

• Korean Journal of Ecology and Environment
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• v.44 no.2
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• pp.103-112
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• 2011

Aquatic contamination by organic pollutants has been a suspected reason for rapid decrease of amphibian populations whose embryonic and larval stages are in an aquatic environment. Amphibian embryos can be a useful model to study the ecoctoxicologial impacts of aquatic pollutants. The obtained toxicological data are useful references for the management of aquatic pollutants in public health because amphibia share many developmental events with terrestrial vertebrates including humans. Safety guidelines for the toxicological effects of aquatic contaminants of chemicals identified as hazardous should be addressed at multiple endpoints. Alkylphenols have been widely-used in agricultural, industrial, and household activities; they contaminate and can persist in aquatic environments. Exposure to alkylphenols results in endocrine disruption in aquatic animals. In this review, we summarize the developmental toxicities of alkylphenols in amphibian embryos and larva according to the exposure route, chemical concentration, duration of exposure, and affected developmental stage together with mechanisms of toxicity and typical patterns of developmental abnormality. The merits of amphibian embryos as a toxicity test model for mid- to long-term exposure to aquatic pollutants are discussed proposed.

• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.477-486
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• 2016

This study was to evaluate of the reliability and validity of the Risk Perception Survey - Diabetes Mellitus (RPS-DM) with Korean diabetes patients. A total of 183 patients participated in this study from December 4, 2014 to January 1, 2015 with self-reported questionnaires. The data was analyzed using exploratory factor analysis, cronbach's alpha, and item to total correlation. The factor structure of the instrument showed the cumulative variance of 45.1% in the factor analysis and a four-factor structure was found to be appropriate. The comparative site risk score matched with the RPS-DM in English except item 7, 8, and 12. The RPS-DM in Korean version has been found to be reliable and valid.