• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.45-45
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• 2017

The Indian meal moth, Plodia interpunctella, is one of the most important pests of stored food in the food processing industry worldwide. To control the Indian meal moth, methyl bromide, phosphine, high carbon dioxide, sulfuryl fluoride and plant essential oil fumigation have been considered. However, these treatments have disadvantages. For example, depleting the ozone layer, showing resistance in insect, low control efficacy or need high cost for treatment. Chlorine dioxide ($ClO_2$) is strong disinfectant and insecticide. The gas caused a malfunction in enzymes. The oxidative stress induced by $ClO_2$ gas treatment damaged to a physiological system and all life stages of P. interpunctella. The gaseous $ClO_2$ is a convincing alternative to methyl bromide for controlling P. interpunctella. The gaseous $ClO_2$ was generated by a chlorine dioxide generator (PurgoFarm Co., Ltd., Hwasung, Korea). It generated highly pure $ClO_2$ gas and the gas blown out through a vent into a test chamber. Gas entry to the chamber was automatically controlled and monitored by a PortaSene II gas leak detector (Analytical Technology, Collegeville, PA, USA). The properly prepared eggs, larvae, pupae, and adults of P. interpunctella were used in this experiment. Data were analyzed using SAS 9.4. Percentage data were statistically analyzed after arcsine-root transformation. Analysis of variance was performed using general linear model, and means were separated by the least significant difference test at P < 0.05. Fumigation is an effective management technique for controlling all stages of P. interpunctella. We found that $ClO_2$ gas treatment directly effects on egg, larvae, pupae and adults of P. interpunctella. The gas treatment with proper concentration for over a day achieved 100 % mortality in all stages of P. interpunctella and short time treatment or low concentration gas treatment results showed that the egg hatchability, pupation rate, and adult emergency rate were lowered compare with untreated control. Also, abnormal pupae or adult rate were increased. Gaseous $ClO_2$ treatment induced insecticidal reactive oxygen species (ROS), and it resulted in fatal oxidative stress in P. interpunctella. Taken together, these results showed that exposure proper concentration and time of the gas control all stages of P. interpunctella by inducing fatal oxidative stress. Further studies will be required to apply the gas treatment under real-world condition and to understanding physiological reaction in P. interpunctella caused by oxidative stress.

• Advances in nano research
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• v.16 no.2
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• pp.127-140
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• 2024

Upon direct/indirect exposure to flame or heat, composite structures may burn or thermally buckle. This issue becomes more important in the natural fiber-based composite structures with higher flammability and lower mechanical properties. The main goal of the present study was to obtain an optimal eco-friendly composite system with low flammability and high thermal buckling resistance. The studied composite consisted of polypropylene (PP) and short abaca fiber (AF) with eggshell powder (ESP) and halloysite clay nanotubes (HNTs) additives. An optimal base composite, consisting of 30 wt.% AF and 70 wt.% PP, abbreviated as OAP, was initially introduced based on burning rate (BR) and the Young's modulus determined by horizontal burning test (HBT) and tensile test, respectively. The effects of adding ESP to the base composite were then investigated with the same experimental tests. The results indicated that though the BR significantly decreased with the increase of ESP content up to 6 wt.%, it had a very destructive influence on the stiffness of the composite. To compensate for the damaging effect of ESP, small amount of HNT was used. The performance of OAP composite with 6 wt.% ESP and 3 wt.% HNT (OAPEH) was explored by conducting HBT, cone calorimeter test (CCT) and tensile test. The experimental results indicated a 9~23 % reduction in almost all flammability parameters such as heat release rate (HRR), total heat released (THR), maximum average rate of heat emission (MARHE), total smoke released (TSR), total smoke production (TSP), and mass loss (ML) during combustion. Furthermore, the combination of 6 wt.% ESP and 3 wt.% HNT reduced the stiffness of OAP to an insignificant amount by maximum 3%. Moreover, the char residue analysis revealed the distinct differences in the formation of char between AF/PP and AF/PP/ESP/HNT composites. Afterward, dilatometry test was carried out to examine the coefficient of thermal expansion (CTE) of OAP and OAPEH samples. The obtained results showed that the CTE of OAPEH composite was about 18% less than that of OAP. Finally, a theoretical model was used based on first-order shear deformation theory (FSDT) to predict the critical bucking temperatures of the OAP and OAPEH composite plates. It was shown that in the absence of mechanical load, the critical buckling temperatures of OAPEH composite plates were higher than those of OAP composites, such that the difference between the buckling temperatures increased with the increase of thickness. On the contrary, the positive effect of CTE reduction on the buckling temperature decreased by raising the axial compressive mechanical load on the composite plates which can be assigned to the reduction of stiffness after the incorporation of ESP. The results of present study generally stated that a suitable combination of AF, PP, ESP, and HNT can result in a relatively optimal and environmentally friendly composite with proper flame and thermal buckling resistance with no significant decline in the stiffness.

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.67-72
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• 2005

In a flour milling facility, control ability of superheating effect on Indian meal moth population was teated. Thirty adults, thirty larvae and 100 eggs were placed in a paper bag ($10{\times}20cm$) containing 100 g flour and were exposed to the temperature higher than $60^{\circ}C$ for longer than 3 hours. Mortality of the Indian meal moth (${\pm}standard error$) varied with the developmental stage; mortality (${\pm}standard error$) of egg, larvae and adult were in the range of $91.40{\pm}0.93{\sim}98.80{\pm}0.20\%,\;96.00{\pm}0.67{\sim}100\%$) and $100\%$, respectively. The position of paper bag caused differences in temperature and its exposure time to the moth during the experiment, consequently. The mortality of moth was significantly different among the bag position. Exposure of the paper bag to the temperature of higher than $60^{\circ}C$ for longer than 11 hours was not sufficient to kill all the eggs.

• Analytical Science and Technology
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• v.23 no.6
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• pp.595-606
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• 2010

A total 221 samples of the retailed foods collected from 2004 to 2007 was examined to estimate the level of dioxins(29 congeners) by the isotopic dilution method, and the exposure of population of Korean to dietary of dioxins was performed. Dioxins levels were calculated using TEF values established in 1998 and 2005, respectively. The average levels (pg TEQ/g) were less than 0.01 for polished rice, 0.04 (poultry)-0.13 (beef) for meats, 0.04 (milk)-0.05(cheese) for milk and dairy products, 0.13 for egg (york, only) and 0.11 (alaska pollack)-1.35 (pacific mackerel) for fishes. The estimated daily intake of Korean through foods was 0.47 pg TEQ/kg bw/day, and it was estimated as about 11% to tolerable daily intake (TDI; 4 pg TEQ/kg bw/day) of Korea and Japan. Consequently, it was concluded that there was no health risk.

• Journal of Chest Surgery
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• v.22 no.4
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• pp.525-547
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• 1989

Hemorrhagic tendency observed in open heart surgery patients has been attributed, among other causes, to increased fibrinolytic activity during extracorporeal circulation. But the exact mechanism of enhanced fibrinolytic activity which occurs during extracorporeal circulation is still unknown. So, we studied and compared the changes of parameters of fibrinolytic and protein C system according to time obtained from the plasma of 31 adult open heart surgery patients[EGG group] and 10 adult general thoracic surgery patients[control group], in order to confirm the hypothesis that the activated protein C system might affect the fibrinolytic system during extracorporeal circulation. In ECC group, the nature of the enhanced fibrinolytic activity that evolved during extracorporeal circulation was characterized by significant increase in fibrin degradation products[P < 0.01] and significant decrease in plasminogen and alpha2-antiplasmin[P < 0.05, P < 0.01] in spite of adequate amount of heparin administration. These changes were most pronounced in the early phase of extracorporeal circulation and normalized after termination of extracorporeal circulation. The results of these observations were the same after volume correction with the value of hematocrit. The change of volume corrected protein C ratio during extracorporeal circulation revealed similar pattern to those of plasminogen and alpha2-antiplasmin [P < 0.01], but volume corrected ratio of free protein S showed significant increase after the commencement of extracorporeal circulation then decreased after extracorporeal circulation. Although the above mentioned changes occur similarly in both bubble type oxygenator-used and membrane oxygenator-used patients groups, but the degree of decrease was more severe in membrane oxygenator-used patients group [P < 0.01] and showed much slower recovery to reach to the preextracorporeal circulation level. These results confirm the hypothesis that the enhanced fibrinolysis during extracorporeal circulation might be caused by the activation of protein C system and the activation is possibly linked to the appearance of thrombin from contact activation of blood after wide exposure to the synthetic surfaces of extracorporeal circuit. Key words: Extracorporeal circulation, Enhanced fibrinolysis, Protein C system.

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.118-125
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• 1985

To establish an evaluation system of aquatic toxicity of chemicals at no-effect level, flow through and early life stage toxicity test were performed on a freshwater fish, the medaka (Oryzias latipes). The characteristics of medaka as a bioassay organism for the chronic toxicity test were discussed. Maximum acceptable toxicant concentration(MATC) of butachlor for the madaka in soft water was estimated using survival, growth, and reproduction as indicators of toxic effects. During a 3-month period, the fry of medaka were exposed to butachor concentrations ranging from 0.16 to 0.0l mg/liter and the DO concentration, temperature, and pH in the exposure chamber were measured to check the test condition. The highest concentration showed slight decrease of growth rate in medaka and reduced hatchability of spawning egg. Survival, growth, and reproductive success of adults in butachlor concentration of 0.04 and 0.01 mg/liter were not different from those of the control. The MATC was estimated to be between 0.04 and 0.16 mg/liter for medaka.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.418-423
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• 2015

Effects of 9 acaricides to the predatory mite, Neoseiulus californicus were evaluated. Seven of the acaricides tested, cyenopyrafen. spirodiclofen, spiromesifen, acequinocyl, bifenazate, flufenoxuron and cyflumetofen exhibited low toxicity to adult females and nymphs of N. californicus and had little effect on the reproduction and eclosion of eggs deposited by treated predators. Moreover, hatch percentage of N. californicus eggs was unaffected by exposure to these seven acaricides. Etoxazole did not significantly affect the survival and reproduction of adult female predators but caused very low eclosion in eggs laid by treated females and high egg mortality. Pyraclofos was extremely toxic to adult female predators and caused 100% mortality. Adult female predators survived on a diet of spider mites treated with cyenopyrafen. spirodiclofen, spiromesifen, acequinocyl, bifenazate, flufenoxuron and cyflumetofen and their fecundity was not substantially affected. Based on the results, cyenopyrafen. spirodiclofen, spiromesifen, acequinocyl, bifenazate, flufenoxuron and cyflumetofen are appeared to be promising candidates for use in integrated mite management program where N. californicus is the major natural enemy.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.179-186
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• 2015

The Pacific oyster Crassostrea gigas oocytes were exposed to 4 cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), methanol, or polyethylene glycol (PEG), each with 4 four concentrations (5, 10, 15, and 20%) and for 10, 20, 30 or 40 minutes for permeation. The oocytes were then fertilized, using normal sperm of the species. Fertilization and hatching rates were clearly influenced by cryoprotectant species and their concentration and permeation time. Overall, they decreased as concentrations and permeation time of cryoprotectants increased with optimum results at concentrations of 5-10% and a permeation time of 10 minutes. Larval abnormalities, a sign of the chemical damage, were a representative phenotype which was higher at a higher concentration and longer duration of the chemicals. In conclusion, best result was from 5% DMSO exposure for 10-20 minute permeation.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1702-1707
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• 2002

The effects of dark-control (D) and continuous green light (GL) exposure of incubated meat-type breeder eggs (Hybro) on embryonic growth from 5 to 15 days of age, hatching time, hatchability per cent and chick hatching weight were investigated in three consecutive experiments at 33, 38, and 41 weeks of age. A total of 798 eggs were used in this study. Eggs were set in an incubator on trays either in the D or under two tubes of 20-watt green fluorescent light during the first 18 days of incubation. Eggs from both treatments were transferred to the dark hatching compartment at 19 days of incubation. The light intensity was in the range of 1,340 to 1,730 lux at the surface of the eggs. GL incubation of eggs significantly (p<0.01) increased weight (expressed as an absolute value) and daily weight gain of embryos at 11 and continued to 15 days of age, hatchability per cent by 4.8%, reduced dead embryos per cent and chick weight at hatch by 37 and 2%, respectively and accelerated hatching time by about 24 h when compared with the D-control incubation. Chicks hatched at 504 h of incubation had significantly (p<0.01) higher body weight, expressed as an absolute value or as a percentage of egg weight, than those hatched earlier at 456 h of incubation. It was concluded that the GL incubation of meat breeder eggs reduced incubation period and chick weight at hatch and increased embryonic growth and hatchability per cent.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3413-3418
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• 2015

Background: Liver fluke infection caused by the parasite Opisthorchis viverrini (O. viverrini), a human carcinogen, is endemic in north-eastern Thailand and remains a major health problem. Objectives: The objectives of the study were to (1) resurvey the prevalence of O. viverrini infection in a field site from the Khon Kaen Cohort Study (in newly recruited subjects as well as previous cohort subjects surveyed in 1992); (2) investigate how subjects' lifestyle habits and their exposure to health promotion initiatives influence changes in prevalence of O. viverrini infection. Materials and Methods: The prevalence of O. viverrini infection in the cohort subjects (as well as new subjects) was investigated using faecal egg counts. Information on demographic factors, lifestyle and awareness of health promotion initiatives were obtained through questionnaires. Results: O. viverrini infection rates in the same individuals of the cohort were lower in 2006 than in 1992. Also, by studying the period effect, the current 35-44 year olds had a 12.4% (95% CI 3.9% to 20.9%) lower prevalence of O. viverrini infection than the 35-44 year olds in 1992 (24.2% versus 11.8%). Lifestyle choices showed that smoking and alcohol consumption were associated with an increased chance of acquiring O. viverrini infection with adjusted odds ratios of 10.1 (95%CI 2.4-41.6) and 5.3 (95%CI 1.2-23.0), respectively. Conclusions: Our study has demonstrated that although the prevalence of O. viverrini infection over a 14-year period has decreased, unhealthy lifestyle was common with smoking and alcohol consumption being associated with increased chances of infection, emphasising the double burden of disease which developing countries are facing.