• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.1
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• pp.76-87
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• 1998

The concentration of welding fume was measured by 221 welders themselves in chassis frame workplace of the manufactory from February, 1, 1996 to May, 31, 1997. Welding parameters were the welding current and the distance between helmet and arc. Those two optimum conditions were proposed by excess probability analysis using logistic regression, so the best position in the workplace was proposed considering two factors to control the welding fume. The results are as followings; 1) The excess proability of welding fume TLV was over 99% in above 260 Amperes of welding current and also in below 30cm of distanced between helmet and arc. 2) The equation from logistic regression analysis using SPSS/PC+5.02 had the welding current as a independent variable and the excess of welding fume TLV as a dependent variable (p<0.05). Logit(welding fume TLV) = 0.1296 ${\times}$ wlding currnet - 28.8750 3) The equation from logistic regression analysis using SPSS/PC+5.02 had the distance between helmet and arc as a independent variable and the excess of welding fume threshold limit value a, a dependent variable (p<0.05). Logit (welding fume TLV) = -0.6809 ${\times}$ distance between helmet and arc +25.1665 4) Considering both cases or 2) and 3). the result equation is following. (p<0.05). Logit (welding fume TLV) = 0.1346 ${\times}$ welding current -0.3859 ${\times}$ distance between helmet and arc -15.7382 5) The excess probability of welding fume threshold limit value was 100% in above 240 Ampere of welding current. Thus, below 220 Ampere can be suggested to reduce the 40% number of welders who have a excess welding fume threshold limit value. 6) The excess probability of welding fume TLV was 100% in below 34cm of distance between helmet and arc. Thus, over 38cm can be suggested to reduce the 33% number of welders who have a excess welding fume TLV. 7) Considering both 5) and 6) cases, first of all, the best welding current can be 200 Ampere to have a below 15% of welding fume excess probability for the welders who works in distance of 34-37cm. Secondly, to have a below 30% excess probability of welding fume TLV, the working distance must be over 38cm in 220 Ampere and 32cm in 200 Ampere. 8) To reduce the average exposure concentration of welding fume ($8.21{\pm}5.83mg/m^3$), the movable local exhaust system equipped with flexible hoods can be used.

• Macromolecular Research
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• v.13 no.3
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• pp.167-175
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• 2005

This review explores recent works involving the use of the self-assembled nanoparticles of bile acid-modified glycol chitosans (BGCs) as a new drug carrier for cancer therapy. BGC nanoparticles were produced by chemically grafting different bile acids through the use of l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The precise control of the size, structure, and hydrophobicity of the various BGC nanoparticles could be achieved by grafting different amounts of bile acids. The BGC nanoparticles so produced formed nanoparticles ranging in size from 210 to 850 nm in phosphate-buffered saline (PBS, pH=7.4), which exhibited substantially lower critical aggregation concentrations (0.038-0.260 mg/mL) than those of other low-molecular-weight surfactants, indicating that they possess high thermodynamic stability. The SOC nanoparticles could encapsulate small molecular peptides and hydrophobic anticancer drugs with a high loading efficiency and release them in a sustained manner. This review also highlights the biodistribution of the BGC nanoparticles, in order to demonstrate their accumulation in the tumor tissue, by utilizing the enhanced permeability and retention (EPR) effect. The different approaches used to optimize the delivery of drugs to treat cancer are also described in the last section.

• Journal of Community Nutrition
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• v.6 no.3
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• pp.146-154
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• 2004

This study compared intake of vitamins and antioxidant nutritional status of smokers and nonsmokers, and the effect of supplementation of vitamin C and vitamin E on antioxidant system of smokers and nonsmokers. Subjects were 30 smokers and 30 non-smokers of male university students. They were divided into groups of 10 subjects each one with supplementation for 4 weeks, to investigate the effects of supplementation. Smokers were divided into vitamin C supplement group, vitamin E supplement group and vitamin C and vitamin E combination supplement group, and so were nonsmokers. The supplementation of vitamin C was 500mg and vitamin E was 400IU. There was no significant difference of antioxidant vitamin intakes between smokers and non-smokers, and plasma concentration of vitamin C in smokers was lower than non-smokers (p<0.05). Blood pressure was higher in smokers (p<0.05), with no difference in blood glucose levels, methemoglobin and TBARS, but SOD activity was significantly higher in non-smokers (p<0.001). Vitamin C supplementation resulted in a significant decrease of diastolic blood pressure (p<0.01), systolic blood pressure (p<0.001) and methemoglobin (p<0.001) in smokers. Also a significant decrease of diastolic blood pressure (p<0.05), systolic blood pressure (p<0.05), blood glucose (p<0.05), methemoglobin (p<0.001) and TBARS (p<0.05), with significant increase of SOD activity (p<0.001) were found in vitamin E supplement group. In vitamin C and vitamin E combination supplement group, there was a significant decrease of diastolic blood pressure (p<0.05), methemoglobin (p<0.01) and TBARS (p<0.05). In non-smokers, methemoglobins (p<0.001) of vitamin C supplement group and vitamin E supplement group decreased, and diastolic pressure (p<0.05), methemoglobin (p<0.01) and TBARS (p<0.05) significantly decreased in vitamin C and vitamin E combination supplement group. These results indicated better efficacy of antioxidant supplementation in smokers than in nonsmokers, suggesting that the supplementation of vitamin C and vitamin E might decrease the oxidative stress and various risk factors of smoking-related diseases.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.6
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• pp.59-68
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• 2005

This study was carried out to investigate soil properties, ordination, and vegetation of the coastal sand dune in Sinduri, Taean-Gun. 1. The Orobanche coerulescens and Ixeris repens that are a peculiar species were found in Sinduri coastal sand dune and the Salix purpurea var. japonica that is an endemic species of korea was found in that place. The plant communities was categorized into seven groups, such as Rosa rugosa community, Vitex rotundifolia communit, Carex kobomugi community, Imperata cylndrica var. koenigii community, Carex pumila community, Artemisia capillaris community, and Calamagrostis epigeios community. 2. The soil organic matter, total nitrogen, available phosphorous concentrations, and cation exchange capacity were lower in the study sites than in forest soil of seashore. There was little difference in soil exchangeable Ca, Mg, and K concentrations between in the study site and in the forest soil of seashore. The soil pH was ranged from 5.69 to 7.63. The soil texture in the study site was sand or loamy sand. 3. The results of the correlation between Sinduri coastal sand dune community and environmental factor are as follows; the soil pH was the most effect to the community distribution, and CEC, total nitrogen, soil organic matter, and the amount of silt in soil have some correlation with community distribution. 4. The results of the correlation between Sinduri coastal sand dune community and soil characteristics are as follows; the Calamagrostis epigeios community was found in area that have high soil moisture content; the Rosa rugosa community was found in area that have high soil CEC, organic matter concentration, and total nitrogen concentration, and low soil pH; the Vitex rotundifolia community, Carex kobomugi community, and Artemisia capillaris community were found in area that have low soil CEC, organic matter concentration, and total nitrogen concentration, and high soil pH; the Imperata cylndrica var. koenigii community and Carex pumila community were found in area that have medium soil CEC, organic matter concentration, total nitrogen concentration, and soil pH.

• The Journal of Korean Medicine
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• v.20 no.3 s.39
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• pp.45-53
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• 1999

Since Radix Stemonae was recorded hypothennal and a little toxic in the 'Myngyubelrok (名醫別錄)', it has been recorded as having the same nature in many herbal books. However, the security of Radix Stemonae when used to treat respiratory disease over a long term has not been studied until now. Therefore, the objective of this study is to determine the effects of Radix Stemonae on the main organs if Radix Stemonae is administrated over a long term. In order to investigate the histological changes of the liver and kidneys of rats after oral administration of Radix Stemonae extract, the experimental rats were subdivided into control, 1, 3, 5, 7, 21, 28 and 35 days after administration groups, and 10 rats per group were used in this study. The control group was sufficiently supplied with water and solid forage. The other groups were administrated the reagent at 5mg/kg once a day by oral injection. Several times each day, the experimental groups were carefully observed for any changes of general condition, toxic symptoms, activity, appearance and the number of dead rats. The experimental groups were weighed and narcotized. For the histological observation, the tissues of liver and kidneys of the experimental groups were collected, stained by hematoxylin-eosin stain, and evaluated by observing the changes of gross appearance and by observing microscopic findings. 1. This drug, during the experimental term, did not induce any toxicological effect in mortality, abnormal symptoms or changes of body weight except for the 1 day after administration groups whose body weights were decreased, compared to the control group. 2. No gross changes of the liver and kidneys were observed in this study. 3. No histological changes of the liver were detected in 1 day after administration groups. However, dilation of the central vein was observed in 3, 5 and 7 days after administration groups and chronic passive congestion of the liver was demonstrated in the 21 days after administration groups. In the 28 and 35 days after administration groups, a centrolobular disposition of fatty tissue (adipose cell) was observed. 4. No histological changes of the kidneys were observed in this study. It is evaluated that if Radix Stemonae is administrated for a long term, it induces toxicity in the liver. So, to examine the toxicity of Radix Stemonae on the liver and kidney, it is necessary that the studies of biochemistry and electron microscopic findings about Radix Stemonae be systematically performed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1063-1072
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• 2011

This study analyzed the functional components and antioxidant activities of pomegranate juice and pomegranate husk, endocarp and seed extracts by comparing Korean and Iranian pomegranates. Korean pomegranate husk (KPH) had the highest total polyphenol content among the pomegranate extracts, and total phytoestrogen content was highest in Korean pomegranate endocarp (KPE). Iranian pomegranate endocarp (IPE) and Iranian pomegranate husk (IPH) showed the highest flavonoid levels. Overall, Korean pomegranate had more functional components than those in Iranian pomegranate. KPE had the highest DPPH radical scavenging activity and superoxide dismutase like-activity among all of the extracts, and KPH had the highest nitrite scavenging activity. IPE showed the highest superoxide anion scavenging activity. The ABTS$^+$ assay also indicated that IPH had the highest antioxidant activities. This study also showed that the more total polyphenols, flavonols, and phytoestrogens the pomegranate contained, the higher antioxidant activities. A positive correlation was observed between total polyphenol, flavonol and phytoestrogen levels and antioxidant activities. Korean pomegranates contained more functional components and had higher antioxidant activity than those of Iranian pomegranates. Additionally, pomegranate endocarp and seed extracts were better than pomegranate juice in terms of functional components and antioxidant activity. These results suggest that pomegranate husk, endocarp and seed extracts as well as pomegranate juice may have value as natural antioxidants with their high quality functional components and antioxidant activity.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.819-824
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• 2016

The accelerated thermal aging of CSPE (chlorosulfonated polyethylene) was carried out for 33.64 and 67.27 days at 110[$^{\circ}C$], equivalent to 40 and 80 years of aging at 50[$^{\circ}C$], respectively. These samples were referred to as CSPE-0y, CSPE-40y and CSPE-80y, respectively. As the accelerated thermally aged years of the CSPE increase, the insulation resistance[$\Omega$] at 20[Hz], 500[Hz], and 2[KHz], and the percent elongation [%EL] of the CSPE decrease. However, the dissipation factor($tan{\delta}$) at 20[Hz], 500[Hz], and 2[KHz], the apparent density[$g/cm^3$], the glass transition temperature and the melting temperature of the CSPE were increased. The period of time that the voltage has to be applied until electric breakdown of the CSPE-0y is longer than that of the CSPE-40y, and the CSPE-80y, but the dielectric strength of the CSPE-80y is lower than that of the CSPE-0y and the CSPE-40y. The differential temperatures after the AC and DC voltages are applied to CSPE-0y, CSPE-40y and CSPE-80y are 0.026~0.028[$^{\circ}C$], 0.030~0.042[$^{\circ}C$], 0.018~0.045[$^{\circ}C$], respectively. The variations of temperature for the AC voltage are higher than those for the DC voltage when an AC voltage is applied to CSPE-0y, CSPE-40y and CSPE-80y. It is found that the dielectric loss owing to the dissipation factor[$tan{\delta}$] is related to the electric dipole conduction current. It is ascertained that the ionic (electron or hole) leakage current is increased by the separation of the branch chain of CSPE polymer from the main chain of the polyethylene as a result of thermal stress due to accelerated thermal aging as well as by conducting ions such as $Na^+$, $Cl^-$, $Mg^{2+}$, $SO_4^{2-}$, $Ca^{2+}$ and $K^+$ after seawater soaking.

• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.183-191
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• 2008

In order to make a functional jam containing garlic, sugar, acid and pectin were mixed with garlic and concentrated by heating the mixture under atmosphere or vacuum conditions. And changes of some physico-chemical properties of the garlic jam(i.e., color, textural properties, vitamin C) were investigated during storage at $30^{\circ}C$. It was found that lightness(L) was higher in sample of vacuum concentration than that in atmosphere concentration and redness(a) and yellowness(b) were higher in sample of atmosphere concentration. During the storage lightness was found to decrease for all samples with more drastic decrease in sample of atmosphere concentration where browning was more severely observed after 8 weeks of storage. In terms of textural properties, hardness, chewiness and gumminess were higher in sample of atmosphere concentration than that in vacuum concentration. And springiness and cohesiveness were higher in sample of vacuum concentration. Although sensory score for garlic jam found to be lower than that for the existing strawberry jam, the present garlic jam might have high marketability if considering its physiological value.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1115-1123
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• 2016

_L-Asparaginase (E.C. 3.5.1.1) is an enzyme involved in asparagine hydrolysis and has the potential to effect leukemic cells and various other cancer cells. We identified the _L-asparaginase gene (_L-ASPG86) in the genus Mesoflavibacter, which consists of a 1,035 bp open reading frame encoding 344 amino acids. Following phylogenetic analysis, the deduced amino acid sequence of _L-ASPG86 (_L-ASPG86) was grouped as a type I asparaginase with respective homologs in Escherichia coli and Yersinia pseudotuberculosis. The _L-ASPG86 gene was cloned into the pET-16b vector to express the respective protein in E. coli BL21 (DE3) cells. Recombinant _L-asparaginase (r-_L-ASPG86) showed optimum conditions at 37-40℃, pH 9. Moreover, r-_L-ASPG86 did not exhibit glutaminase activity. In the metal ions test, its enzymatic activity was highly improved upon addition of 5 mM manganese (3.97-fold) and magnesium (3.35-fold) compared with the untreated control. The specific activity of r-_L-ASPG86 was 687.1 units/mg under optimum conditions (37℃, pH 9, and 5 mM MnSO₄).

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.88-95
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• 1986

Clinically, subhypnotic doses of barbiturates have been known to elicit hyperalgesia. In this experiment, effect of acute or chronic phenobarital treatment on the response to pain in rat was reevaluated by hot-plate method. To elucidate its mechanism, changes of ${\beta}-endorphin$ contents and [3H]-morphine binding of the rat midbrain as well as functional opiate receptor in vas deferens were also measured. Intraperitoneal injection of sub anesthetic dose phenobarbital induced initial hyperalgesia followed by successive analgesia, while chronic phenobarbital-treatment decreased reactivity to pain. Naloxone (10mg/kg, i.p.) markedly shortened hot plate latency period, and significantly inhibited the analgesic action of phenobarbital. Single dose of phenobarbital did not affect ${\beta}-endorphin$ contents and [3H]-morphine binding in rat mid brain, but in the chronic phenobarbital-treated groups, ${\beta}-endorphin$ contents was increased, while Bmax of opiate receptor binding was decreased. Moreover, very significant correlations among responses to pain, changes of ${\beta}-endorphin$ contents and opiate receptor binding were observed. However, Kd values of opiate receptor bindings were not changed in all preparations. In the chronic phenobarbital-treated vas deferens preparations, ID50 of morphine was increased witb concomittant decrease of maximum effect. But $pA_2 $, value for naloxone was not changed. From these results, it is suggested that phenobarbital can produce analgesia due to changes of ${\beta}-endorphin$ contents as well as functional opiate receptors by receptor regulation.