• Journal of Environmental Science International
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• v.12 no.6
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• pp.593-598
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• 2003

The effects of bisphenol A on the catalase activities in the development stage of zebrafish were investigated. In this study, the catalase activities for zebrafish fries exposed to bisphenol A of 1${\times}$10$\^$-10 g/$\ell$ during 1 week, 2 week, and 4 week post-hatching were examined. Also, the changes of organs weight and the catalase activities for adult zebrafishes exposed to bisphenol A during 3 weeks were investigated. Catalase activities for zebrafish fries exposed to bisphenol A of 1${\times}$10$\^$-10/ g/$\ell$ during 1 week post-hatching were significantly lower, compared to the control. Somewhat, for zebrafish fries exposed to bisphenol A during 4 week post-hatching, catalase activities were significantly increased. For adult zebrafishes, the effects of bisphenol A were higher for female than male. Specially, catalase activities were significantly increased in the ovary of zebrafishes exposed to bisphenol A during 3 weeks. The ovary weight were increased for zebrafishes exposed to bisphenol A during 3 weeks. Catalase activities were increased in the intestine of female exposed to bisphenol A during 3 weeks. Catalase activities were increased in testis exposed to bisphenol A during 3 weeks but there was no significance. In conclusion, the damages of an endocrine disrupter were higher in the earlier development stage compared with adult. The damages were higher for female exposed to an endocrine disrupter compared with male.

• Korean Journal of Veterinary Research
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• v.29 no.3
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• pp.343-359
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• 1989

To study the effects of ibaraki virus on preimplantation mouse embryos collected from prepubertal ICR and BALB/cByJ mice (30~40days old) by superovulation, zona pellucidaintact(ZPI) or free(ZPF) embryos(n=774) of 4- to 8-cell and morulae were exposed to $10^{5.8}$ $TCID_{50}$ of the virus up to 96 hours. The embryos were examined morphologically by observing the degeneration and hatching rates, and virologically and immunologically by determining the presence of infection with the virus, in addition, the effect of washing the embryos to remove virus possibly attached to was also investigated. The ZPI 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rate than those not exposed, for 96, and for 72 to 96 hours, respectively(p<0.01). The ZPF 4- to 8-cell embryos and morulae exposed to the virus showed considerably higher degeneration rates than those not exposed, throughout the whole culture hours in vitro (p<0.01). The ZPI 4- to 8-cell embryos and morulae not exposed to the virus showed considerably higher rates of hatched blastocyst than those exposed (p<0.01). The virus infection rates of the ZPF 4- to 8-cell embryos and morulae were significantly higher than those of the ZPI embryos according to cell culture system. The viral antigen was detected exclusively on the zona pellucida of ZPI embryos, while the antigen was evenly distributed in the blastomeres of ZPF embryos by the immunofluorescent assay. In the ZPI embryos exposed to ibaraki virus, the virus was detected in the two times-washing groups, but not in the ten times-washing groups. The results indicated that zona pellucida of murine embryos would provide an effective protection and that ten times-washing of the ZPI embryos previously exposed to the virus was effective to remove virus from the embryos.

• Journal of information and communication convergence engineering
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• v.10 no.2
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• pp.135-140
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• 2012

Massive numbers of users of social networks share various types of information such as opinions, news, and ideas in real time. As a new form of social network, Twitter is a particularly useful information source. Studying influence can help us better understand the role of social networks. The popularity of social networks like Twitter is primarily measured by the number of followers. The number of followers in Twitter and the number of users exposed to news media are important factors in measuring influence. We chose Twitter and the New York Times as representative media to analyze the influence and present an empirical analysis of these datasets. When the correlation between the number of followers in Twitter and the number of users exposed to the New York Times is computed, the result is moderately high. The correlation between the number of users exposed to the New York Times and the number of sections including the users on it, was found to be very high. We measure the normalized influence score using our proposed expression based on the two correlation coefficients.

• Journal of Life Science
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• v.9 no.2
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• pp.136-145
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• 1999

The purpose of this study was to evaluate the effect of organic slovents and noise on hearing loss. We selected organic solvents exposed group of 32 cases, noise exposed group of 31 cases, both noise and solvent exposed group of 31 cases, and control group of 53 cases and studied the relation between exposure level of noise and organic solvents and degree of hearing loss. The results were as follows. The subjects under investigation were exposed to noise and organic solvents under threshold limit values and the amount of urinary hippuric acid excretion were also under biological exposure indices. In case of noise, both noise and organic solvents exposed group and noise exposed group were more exposed than organic solvents exposed group(p<0.05). When urinary hippuric acid excretion were concerned, both noise iud organic solvents exposed group and organic solvents exposed group showed higher values than noise exposed group(p<0.05). In comparison of mean auditory threshold values by frequency, on the air conduction test, both noise and organic solvents exposed group showed significantly higher hearing loss than noise exposed group in 500Hz of right ear, 500 and 2000Hz of left ear(p<0.05). Forty-three cases among 147 subjects were regarded as hearing loss group and average age(42.6years) of hearing loss group was higher than normal groups average age of 38.0 years. Urinary hippuric acid excretions of hearing loss group were significantly higher than normal group(p<0.05). Thirty-eight percent(12cases) of noise exposed group, 40.6 $\%$(13cases) of organic solvents exposed group, 51.6 $\%$(16cases) of both noise and organic solvents exposed group, and 3.8 $\%$(2cases) of unexposed group were regarded as hearing losers. Exposed groups showed higher incidence of hearing loss than unexposed group but there were no significant differences among the exposed groups. The variables showing significant correlation with hearing loss were age and the amount of hippuric acid in urinary excretion. When age were adjusted for the purpose of seeing the effects of hearing losses due to organic solvent, urinary excretion of hippuric acids was the only variable with significant correlation with hearing loss (p<0.05). When odds ratio to hearing loss between control and exposed groups was considered, noise exposed group showed 6.1 times (95 $\%$ CI: 3.3-8.7), organic solvents exposed group showed 7.4 times (95 $\%$ CI: 3.5-14.6) and both noise and organic solvents exposed group showed 17.2 times(95% CI: 5.6-31.8) higher values than unexposed group(p<0.01). Above results suggest that health screening test of hearing loss is also needed in organic solvents exposed workers.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.76-86
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• 1979

This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

• Journal of Biosystems Engineering
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• v.4 no.1
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• pp.75-75
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• 1979

This study was conducted to find out the effects of rainfall occurring during the paddy sun-during process of traditional paddy harvesting operations on the quality of milld rice. Rice varieties used for the experiment were MINEHIJARI variety a japonica and SUWEON 264 vareity , a sister-line of TONG-IL . Sun-drying days after the paddy cutting, times of storm occurrance during sun-drying period, and storm duration were treated as variables. The results is summarised as follows : 1. Brown rice recovery exposed to rainfall during the sun-druing period were ranged 81.6-82.1% and 79.4-80.2% for MINEHIKARI and SUWEON 264 varieties, respectively. which showed negligible effect by rainfall. 2. Milling recovery of MINEHIKARI variety was not affected by storm duration but by the by the sun-drying days after cutting as the sun-drying days increased to eight and four days when the variety met the rainfall one and two times, respectively. The range of milling recoveries of MINEHIKARI variety were 75.18-74.07% and 75.24-73.46% as the variety met the rainfall one and two times, respectively, and it were estimated that up to 0.9% and 1.5% of milling recovery would be reduced by one and two times of rainfall during sun-drying period. 3. The milling recovery of SUWEON 264 variety was affected only by the increase of drying days after cutting when it met one time of rainfall during the sun-drying period, while it was begun to reduce by the storm duration more than 11hours as the drying paddy met two times of rainfall. The milling reveries of the paddy met one and two times of rainfall were ranged 74.24-73.21% and 74.02-72.36% which were estimated to be reduced up to 0.9 % and 1.8% by the increase of the drying days after cutting and storm duration , respectively. 4. The head rice recovery of MINEHIKARI rice variety showed notable decrease as the drying days after cutting increased, and also it was greatly reduced even by the five hours of storm duration when one time of rainfall occurred but it was not affected by storm duration when the rainfall occurred two times. Head rice recoveries of MINEHIKARI met one and two times of rainfall during the sun-drying period were 65. 15 -40.85% and 61.86 - 30.03 %, which showed terrible reduction as much as up to 25% and 35% compared to that which did not met rainfall during the sun-drying process. 5. Head rice recovery or SUWEON 264 variety was very much reduced as the sum-drying days after cutting increased. Storm duration less than five hours during the sun-drying process did not affect on the decrease of head rice recovery when the variety was exposed to one time of rainfall, while storm duration affected considerably on the reduction of head rice recovery of SUWEON 264 variety exposed to two times of rainfall. The range of head rice recovery, 56.43 - 33.94% and 51.28 - 21.03% , for the paddy exposed to rainfall one and two times were evaluated that up to 24% and 37% of reduction in head rice recovery would be brought about compared to the head rice recovery of the sundriedpaddy that did not met the rainfall.

• Transactions on Electrical and Electronic Materials
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• v.8 no.3
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• pp.115-120
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• 2007

Reliability between passivated and unpassivated process with the base-exposed InGaP/GaAs HBTs was studied. A passivation of HBT was attempted by $SiO_2$ thin film deposition at $300^{\circ}C$ by means of PECVD. Base-exposed InGaP/GaAs HBTs before and after passivation were investigated and compared in terms of DC and RF performance. Over a total period of 30 days, passivated HBTs show only 2% degradation of DC current gain for the high current density of $40KA/cm^2$. The measured thermal resistance of $2{\times}30{\mu}m^2$ single emitter InGaP/GaAs HBT passivated with PECVD $SiO_2$ devices can be extracted and was founded to be 1430 K/W. The estimated MTTF was $2{\times}10^7hr\;at\;T_j=125^{\circ}C$ with an activation energy $(E_a)$ of 1.37 eV.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.13 no.3
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• pp.368-375
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• 2006

Purpose: The purpose of this study was to investigate the risk factors of exposure to blood and body fluid by clinical nurses. Method: The participants in this descriptive study were 276 clinical nurses involved in nursing care in a general hospital located in Seoul. The collected data were analyzed using a logistic regression model. Results: The annual exposure rate to blood and body fluid by clinical nurses was 66.3%, and the ratio was higher in the exposed group than in the non-exposed group for nurses under the age of 25, nurses who were unmarried, nurses with low clinical experience, and nurses who work night shifts more than six days a week. Clinical nurses who were unmarried were 1.9 times more likely to have been exposed compared to married nurses. Nurses whose work experience was less than 18 months were 2.7 times more at risk than nurses with more than 18 months of experience. Also, nurses whose fatigue scores were high had an increased chance of exposure (1.9 times). Conclusion: It is necessary to provide intensive training programs for clinical nurses who are in the early months of their career and are likely to be young and unmarried, in order to prevent exposure to blood and body fluid. Administrative supports to self-control and hospital ward operation measures to relieve nurses' fatigue should be provided.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.216-219
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• 2006

After long exposure to low-density $SO_2$ the five tree species showed different changes in their visible damage: Ailanthus altissima showed no visible damage; Acanthopanax sessiliflorus, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed typical damage of yellow spots on their leaves; and Liriodendron tulipifera showed serious damage on the end of leaf tip. The photosynthesis rate of Liriodendron tulipifera and Acanthopanax sessiliflorus was usually lower than the control group: Ailanthus altissima, Populus alba ${\times}$ Populus glandulosa, and Platanus orientalis showed no difference from the control group, while Acanthopanax sessiliflorus and Liriodendron tulipifera showed large changes. In regard to the light compensation points, Ailanthus altissima showed similar values, Populus alba ${\times}$ Populus glandulosa and Platanus orientalis exposed to $SO_2$, showed 3 to $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ higher values than the control group, and Acanthopanax sessiliflorus and Liriodendron tulipifera exposed to $SO_2$ showed approximately twice higher light compensation points.

• Journal of Embryo Transfer
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• v.19 no.1
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• pp.35-42
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• 2004

The purpose of this study was to evaluate the effects of Cytochalasin B treatment on the survivability The different concentration and exposed times of CB of porcine embryos frozen by vitrification were observed. The results were summarized as follows ; 1. The survivability rates of the porcine embryos treated CB(60.5%) were significantly higher than non-treated(32.8%)(p＜0.1). However the recovered with normal morphology rates(84.2%) were no significantly different than non-treated(81.9%). 2. We observed by different concentration of CB treatment, the group of CB treated with 7.5 $\mu\textrm{g}$/$m\ell$ were significantly showed a higher of normal morphology(44/45; 98%) and viability rate(33/45;73%) than other groups(morphology: 65∼70%, viability: 15∼74%)(p<0.05). While the control was lower as 70% of morphology and 38% of viability. 3. We examined exposed time of in-vitro CB treated embryos, the group of more than 20 minutes exposed were significantly were observed a higher rates of normal morphology and viability(p<0.05). And the group of 13 minutes, 14,000 rpm centrifuged(64%) were significantly higher than non-centrifuged(36%). Survivability of porcine embryos were improved in CB treated group. It suggested that 7.5 $\mu\textrm{g}$/$m\ell$ concentration of CB treatment, 20 minutes exposed times and 13 minutes, 14000 rpm centrifuged prior to vitrification improve normal morphology and survivability rates.