• Analytical Science and Technology
• /
• v.24 no.4
• /
• pp.243-248
• /
• 2011

A selective determination method of mercury (II) ion in aqueous solution by luminol-based chemiluminescence system (luminol CL system) has been developed. Determination of metal ions such as copper (II), iron (III), chromium (III) ion in solution by the luminol CL system using its catalytic role in the reaction of luminol and hydrogen peroxide has been reported by several groups. In this study, the catalytic activity of mercury (II) ion in the reaction of luminol and hydrogen peroxide was observed by the enhanced CL intensity of the luminol CL system. Based on this phenomenon, experimental conditions of the luminol CL system were investigated and optimized to determine mercury (II) ion in aqueous solution. While mercury (II) ion in mixed sample solution containing mercury (I) and (II) ions highly enhanced the CL intensity of the luminol CL system, the mercury (I) ion could not enhanced the CL intensity. Thus selective determination of the mercury (II) ions in a mixture containing mercury (I) and (II) ions could be achieved. Each concentration of mercury (I) and (II) ions in aqueous solution can be obtained from the results of the CL method that give the concentration of only mercury (II) ion and the inductively coupled plasma (ICP) method that give the total concentration of mercury ions. On the optimized conditions, the calibration curve of mercury (II) ion was linear over the range from $1.25{\times}10^{-5}$ to $2.50{\times}10^{-3}M$ with correlation coefficient of 0.991. The detection limit of mercury (II) ion in aqueous solution was calculated to be $1.25{\times}10^{-7}M$.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.6
• /
• pp.570-581
• /
• 2013

To improve productivity of aquaculture animals with management of culturing grounds, survey of mariculture management area in Ongjin-gun about water quality and sedimentary environment had been conducted on June, August and November in 2011. Water temperature in surface and bottom waters ranged from 9.49 to $24.14^{\circ}C$. Salinity and dissolved oxygen concentrations were in the range of 23.19~31.49 and 5.48~9.36 mg/L, respectively, depending on the variation of water temperature. The average concentration of COD was 1.57 mg/L and the concentrations of DIN and DIP showed entirely low level. As the result of grain size analysis, sand(56.66 %) and silt(34.60 %) were predominated. The Mz of sediment showed a variation of 2.59 to $6.62{\O}$ and sorting appeared to be poorly sorted. The concentrations of COD and IL in surface sediment ranged from 1.00 to $11.03mg/g{\cdot}dry$ and 0.72 to 5.29 %, respectively, which showed relatively good positive correlations. On the environmental assessment of trace metals in surface sediment, geoaccumulation index ($I_{geo}$) class indicated that sediments were not contaminated by most of metallic elements except Cr and As. Our result implies that this study area showed good water quality and sediments were not polluted by organic matters and metallic elements.

• Clinical and Experimental Pediatrics
• /
• v.48 no.10
• /
• pp.1061-1067
• /
• 2005

Purpose : We studied a clinical analysis of pediatric patients who visited the emergency medical center of Yeungnam University Hospital to compare the characteristics of pediatric emergency patients after year 2000 with the previous studies. Methods : We reviewed 7,034 children under the age of 15 years who visited the emergency medical center of Yeungnam University Hospital during the 2 year period from January 2001 to December 2002, and then we performed a clinical and statistical analysis. We analyzed the pediatric patients according to gender, age, season, day of the week, time of the visit, the disease classification and the final disposition of the patients. Results : Among the patients who visited the emergency room, 15.6% of the total emergency patients were under the age of 15. The male to female ratio was 1.6 : 1. Among the 7,034 pediatric patients, the most common age group was between 1 year and under 3 years of age(26.9%). The peak seasonal incidence was early summer and spring, especially during June(11.2%) and May(10.6 %). The peak incidence day of the week was Sunday(24.8%) and the peak time when the emergency pediatric patients visited the emergency room was between 20 and 24 o'clock(28.8%). The distribution of diseases, according to ICD-10 system, were injury and poisoning(30.4%), diseases of the respiratory system(22.8%), and diseases of the digestive system(14.6%). 30% of total pediatric patients were admitted to the hospital. Conclusion : After year 2000, as compared with the previous studies, the proportions of emergency pediatric patients has decreased. The distribution of diseases was not much different from the previous studies and the proportions of non-urgent diseases, such as acute nasopharyngitis or acute gastroenteritis, were still high. These result have come about due to the declining birth rate and changes of the medical system in Korea.

• The Korean Journal of Pharmacology
• /
• v.27 no.2
• /
• pp.155-166
• /
• 1991

In order to evaluate a potential role of mitochondria in the mediation of toxicity of paraquat (PQ), submitochondrial particle and microsome of mouse liver were compared by oxygen radical generation and lipid peroxidation. With NADH in submitochondrial particle and NADPH in microsome as electron donors, PQ stimulated production of superoxide anion and $H_2O_2$ in both fractions. Under the same conditions, PQ enhanced the generation of ethylene from methional suggestiong stimulation of OH production by PQ. But these effects by PQ were somewhat lower in submitochondrial particle than in microsome. In addition, lipid peroxidation(measured as MDA production) was stimulated by PQ in both fractions. The stimulation of lipid peroxidation in both fractions seemed to occur by the same mechanism probably through perferryl ion. This was supported by the following findings: i) The lipid peroxidation in both fractions was partially inhibited by SOD and completely inhibited by DETAPAC(an iron chelator) but not by catalase or OH scavenger. ii) Addition of $ADP-Fe^{3+}$ further increased PQ-induced lipid peroxidation but decreased ethylene production from methional suggesting no correlation between OH production and lipid peroxidation. The redox-cycling of PQ in mitochondria appeared to be linked to NADH dehydrogenase, not to CoQ since all of the observed stimulations by PQ in submitochondrial particle were inhibited by p-hydroxymercuribenzoate(a NADH dehydrogenase inhibitor) but not affected by other respiratory chain blockers. The above results demonstrate that redox-cycling properties of PQ leading to oxygen radical generation and lipid peroxidation can also occur in mitochondria in the same manner as in microsome. Therefore, the observed actions of PQ in mitochondria suggest that mitochondria may also contribute to toxicity of this drug in vivo.

• The Journal of Korean Society for Radiation Therapy
• /
• v.19 no.1
• /
• pp.1-5
• /
• 2007

Purpose: The accuracy and advantages of OBI(On Board Imager) against the conventional method like film and EPID for the setup error correction were evaluated with the analysis of the accumulated data which were produced in the process of setup error correction using OBI. Materials and Methods: The results of setup error correction using OBI system were analyzed for the 130 patients who had been planned for 3 dimensional conformal radiation therapy during March 2006 and May 2006. Two kilo voltage images acquired in the orthogonal direction were fused and compared with reference setup images. The setup errors in the direction of vertical, lateral, longitudinal axis were recorded and calculated the distance from the isocenter. The corrected setup error were analyzed according to the lesion and the degree of shift variations. Results: There was no setup error in the 41.5% of total analyzed patients and setup errors between 1mm and 5mm were found in the 52.3%. 6.1% patients showed the more than 5mm shift and this error were verified as a difference of setup position and the movement of patient in a treatment room. Conclusion: The setup error analysis using OBI in this study verified that the conventional setup process in accordance with the laser and field light was not enough to get rid of the setup error. The KV images acquired using OBI provided good image quality for comparing with simulation images and much lower patients' exposure dose compared with conventional method of using EPID. These advantages of OBI system which were confirmed in this study proved the accuracy and priority of OBI system in the process of IGRT(Image Guided Radiation Therapy).

• Journal of Nutrition and Health
• /
• v.44 no.2
• /
• pp.131-139
• /
• 2011

The purpose of this study was to obtain information related to life style characteristics, school achievement and snacking behaviors among underweight and overweight adolescents in Ulsan area. The survey was carried out by self-questionnaires with 464 adolescents (333 underweight and 131 overweight). The results were as follows: Average BMI of the subjects was $19.81{\pm}3.10\;kg/m^2$ which was normal range, but average BMI of underweight and overweight were $16.90{\pm}1.19\;kg/m^2$ and $25.38{\pm}2.16\;kg/m^2$ respectively. The 49.5% of underweight and 94.7% of overweight students have correct perception about their body image. In the sleeping time, 58.9% of underweight and 66.4% of overweight students go to bed after PM 12 o'clock. In the regularity of eating breakfast, 68.5% of underweight and 67.9% of overweight students skipping breakfast at least 5 times per week. 32.6% of the subjects had snack once or more a day. Underweight students had more frequently ate snack than overweight students. The criteria of choosing snack were taste (77.4%), nutrition (9.3%), and price (6.3%). Food as snack they frequently had fruits, milk & milk products, cookies in order. Underweight students had more dodkboki & sundae, candy & chocolate and cake & bread than overweight students, although overweight students had more milk & yogurt than underweight students. The group who had a higher school record, they significantly had more fruits, milk & milk products (p < 0.01) and had not less nutritious foods (p < 0.001). This study may provide basic information on weight status, sleeping and snacking behaviors of adolescents. Therefore they should have nutrition education program to improve their life style and snacking patterns for underweight and overweight adolescents toward healthy weight.

• Restorative Dentistry and Endodontics
• /
• v.33 no.2
• /
• pp.133-140
• /
• 2008

The purpose of this study was to compare the apical micro leakage in root canal filled with Resilon by several self-etching primers and methacrylate-based root canal sealer. Seventy single-rooted human teeth were used in this study. The canals were instrumented by a crown-down manner with Gate-Glidden drills and .04 Taper Profile to ISO #40. The teeth were randomly divided into four experimental groups of 15 teeth each according to root canal filling material and self-etching primers and two control groups (positive and negative) of 5 teeth each as follows: group 1 - gutta percha and $AH26^{(R)}$ sealer: group 2 - Resilon, $RealSeal^{TM}$ primer and $RealSeal^{TM}$ sealer: group 3-Resilon, Clearfil SE $Bond^{(R)}$ primer and $RealSeal^{TM}$ sealer group 4-Resilon, $AdheSe^{(R)}$ primer and $RealSeal^{TM}$ sealer. Apical leakage was measured by a maximum length of linear dye penetration of roots sectioned longitudinally by diamond disk. Statistical analysis was performed using the One-way ANOVA followed by Scheffe's test. There were no statistical differences in the mean apical dye penetration among the groups 2, 3 and 4 of self-etching primers. And group 1, 2 and 3 had also no statistical difference in apical dye penetration. But, there was statistical difference between group 1 and 4 (p < 0.05). The group 1 showed the least dye penetration. According to the results of this study, Resilon with self-etching primer was not sealed root canal better than gutta precha with $AH26^{(R)}$ at sealing root canals. And there was no significant difference in apical leakage among the three self-etching primers.

• The Korean Journal of Pharmacology
• /
• v.30 no.3
• /
• pp.321-330
• /
• 1994

The protective effect of 'ischemic preconditioning (PC)' on ischemia-reperfusion injury of heart has been reported in various animal species, but without known mechanisms in detail. In an attempt to investigate the cardioprotective mechanism of PC, we examined the effects of PC on the myocardial oxidative injuries and the oxygen free radical production in the ischemia-reperfusion model of isolated Langendorff preparations of rat hearts. PC was performed with three episodes of 5 min ischemia and 5 min reperfusion before the induction of prolonged ischemia (30 min)-reperfusion(20 min). PC prevented the depression of cardiac function (left ventricular pressure x heart rate) observed in the ischemic-reperfused heart, and reduced the release of lactate dehydrogenase during the reperfusion period. On electron microscopic pictures, myocardial ultrastructures were relatively well preserved in PC hearts as compared with non-PC ischemic-reperfused hearts. In PC hearts, lipid peroxidation of myocardial tissue as estimated from malondialdehyde production was markedly reduced. PC did not affect the activity of xanthine oxidase which is a major source of oxygen radicals in the ischemic rat hearts, but the myocardial content of hypoxanthine (a substrate for xanthine oxidase) was much lower in PC hearts. It is suggested from these results that PC brings about significant myocardial protection in ischemic-reperfused heart and this effect may be related to the suppression of oxygen free radical reactions.

• The Journal of Natural Sciences
• /
• v.5 no.2
• /
• pp.49-62
• /
• 1992

This study was carried out to investigate the emergence, growth and yield components in rice inassoccation with Several cultivation methods direct sowing flooded paddy field(DSF), direct sowing by airplane(DSA), direct sowing in dry paddy field(DSD), 8days seedling planting(8DS), and 35days seedlingplanting(35DS). Also this study was attempeted to know the effects of calcium peroxide on germinationand early growth of rice under different soil conditions, seeding depth, application of organic matter,indirect sowing flooded paddy field.1. Rate of emergence was 73% in DSF, 70% in DSA, 62% in DSD, respectively, under the different cultivation method of rice in reclaimed paddy field.2. Degree of lodging in relation to cultivation was 5 at both DSF and DSA, 3 at DSD, 2 at both 8DS and 35DS respectively.3. Maximum tiller number was 568 per m2 at DSF and 527 at DSA. Heating was delayed for 4 days at DSF, 8 days at DSD and 2 days at 8DS as comparison with that at 35DS.4. Yield was higher 1% to 3% at DSF than that at DSA and DSD while decreased by 12% as compared with that of seedling planting.5. Total dry weight of seedling was decreased by 57% at 8DS, 60% at DSF 63% at DSD, respectively, under 0.3% of salinity. Ratio of decreasing in dry weight was higher with high salinity.6. The amount of O2 released was recorded highest to 2 to 3days after irrigatition, thereafter remaining constant to 10 days after irrigatition.7. The optimum coating amount of calcium peroxide for germination was a half of rice seed weight with 1 cm sowing depth and one-fold with 2-cm sowing depth when rice straw was not applied. With rice straw applied, on the other hand, the amount of peroxide was one-fold with 1-cm sowing depth. It was found that, under the condition of applied 600kg/10a, of 2-cm soil depth with rice straw calcium peroxide coating had no effect on emergence of rice seedling.8. In reclaimed paddy field, lodging degree was 7 with direct sowing by machine and 9 with direct sowing by hand.9. Yield was increased by 5% by applying rice straw with direct sowing by machine.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.33 no.4
• /
• pp.263-267
• /
• 2007

Parabens are used in nearly all types of cosmetics and toiletries because they are formulated well and have broad spectrum of activity, interness, low costs and excellent chemical stability in relation to pH. 2-phenoxyethanol and chlorphenesin are common preservatives which are usually used in combination with parabens in cosmetics. Toxicity of parabens is generally low but application of parabens to damaged or broken skin has resulted in sensitization. Moreover, the possibility of their estrogenic potential, anesthetic effects and reproductive toxicity has been reported. Consequently there are some regulations in use of parabens. And the maximum permitted concentrations of chlorphenesin and 2-phenoxyethanol in cosmetic products are authorized by the same reasons. So it is important to control and estimate the amount of parabens in products. In this article, we proposed a valid method for the simultaneous determination of 8 preservatives including parabens in a short time using ultra performance liquid $chromatography^{TM}\;(UPLC^{TM})$. Separation of eight components was achieved in less than 10 min and resolutions were reasonable (USP resolution ${\geqq}\;2$). And limit of detection and quantification were evaluated. The method was suitably validated for specificity, linearity, precision (repeatability, intermediate precision) and accuracy for assay (recovery) based on International conference on harmonisation (ICH) guideline. The method was applicable to analysis of preservatives in cosmetic products.