• Journal of Soil and Groundwater Environment
• /
• v.14 no.6
• /
• pp.35-44
• /
• 2009

Naphthalene and TNT (2,4,6-trinitrotoluene) are defined by U.S. EPA as possible carcinogenic compounds known to have detrimental effects on the aquatic ecosystem and human body. There are, however, few researches on methods of analyzing micro-levels of naphthalene and TNT dissolved in groundwater. This study introduces and evaluates the newly developed analytical methods of measuring naphthalene and TNT in groundwater by using HPLC-FLD (Fluorescence detector) and MSD (Mass detector). The MDL, LOQ and salt effect of these methods, respectively, are compared with those of conventional methods which use HPLC-UV. For the analysis of naphthalene, HPLC-FLD was set in the maxima wavelength (Ex: 270 nM, Em: 330 nM) obtained from 3D-Fluorescence to be compared with HPLC-UV in 266 nM wavelength. The MDL ($0.3\;{\mu}g/L$) and LOQ ($2.0\;{\mu}g/L$) of naphthalene by using HPLC-FLD were approximately 80 times lower than those analyzed by HPLC-UV (MDL: $23.3\;{\mu}g/L$, LOQ: $163.1\;{\mu}g/L$). HPLC-MSD were used in comparison with HPLC-UV in 230 and 254 nM wavelength for the analysis of TNT. The MDL ($0.13\;{\mu}g/L$) and LOQ ($0.88\;{\mu}g/L$) of TNT analyzed by using HPLC-MSD were approximately 130 times lower than those obtained by using HPLC-UV in 230 nM (MDL: $16.8\;{\mu}g/L$, LOQ: $117.5\;{\mu}g/L$). The chromatogram of TNT analyzed by using HPLC-UV in 230 nM displayed elevated baseline as the concentration of ${NO_3}^-$ increases beyond 21 mg/L, while the analysis using HPLC-MSD did not demonstrate any change in baseline in presence of ${NO_3}^-$ of 63.7 mg/L which is 3.5 times higher than average concentration in groundwater. In conclusion, HPLC-FLD and HPLC-MSD may be used as suitable methods for the analysis of naphthalene and TNT in groundwater and drinking water. These methods can be applied to the monitoring of naphthalene and TNT concentration in groundwater or drinking water.

• Korean journal of food and cookery science
• /
• v.30 no.4
• /
• pp.402-411
• /
• 2014

This study investigated the quality characteristics of tea leaf pickle with different pickling solutions. Blanched tea leaf at $100^{\circ}C$ for 3 min was pickled using pickling solutions (mixture of water, soy sauce, sugar and vinegar) with different vinegar contents (10, 20, 30 and 40%, v/v). and stored for 30 days at $4^{\circ}C$. The color values, hardness, pH, total acidity, sensory evaluation, antioxidant compound contents, DPPH radical scavenging and ABTS radical scavenging of the pickled tea leaf during storage were determined. The pH of tea leaf pickles decreased consistently and total acidity was increased during storage. The L-value of tea leaf pickles was decreased and the a-value was increased significantly during storage; however, the b-value had no significant changes (p<0.05). The hardness of the tea leaf pickles decreased consistently during storage. On the sensory evaluation, the highest score of overall acceptance was presented to the tea leaf pickle using a 20% vinegar pickling solution stored for 20 days. The antioxidant compound contents and antioxidant activity consistently decreased during storage; further, the experimental group of vinegar with 20% content tea leaf pickle displayed the lowest antioxidant compound content and antioxidant activity.

• The Journal of the Korean bone and joint tumor society
• /
• v.19 no.1
• /
• pp.9-13
• /
• 2013

Purpose: We evaluated oncologic outcomes of chondrosarcomas and analyzed the disease-free survival rate of chondrosarcomas according to the various factors. Materials and Methods: We performed a retrospective study for the disease-free survival rate of 48 chondrosarcomas, 44 of which underwent surgical treatment and followed up more than 18 months since 1993, and in the remaining 4 cases, the patients died before 18 months after surgery. The vsariables were location, tumor volume, histologic grade, stage, age at presentation and treatment performed. The mean follow up period was 43.8 months (1-196 months). Results: The overall disease-free survival rate was 77.1% at mean 43.8 month follow up. The 5 year- and 10 year disease-free survival rates were 64% and 58% respectively. The histologic grade, stage, age at presentation revealed statistical significance on disease-free survival. All 9 patients treated with extended curettage for grade 1 central chondrosarcomas revealed disease-free survival with excellent functional outcome. Conclusion: The disease-free survival rate of chondrosarcomas mainly depended on histologic grade, stage and age at presentation. Local recurrence and distant metastasis also revealed statistically significant differences of disease-free survival rate. Comparing to wide resection, extended curettage for low-grade central chondrosarcomas in extremities were efficient methods with similar survival rate and less functional losses and complications.

• Journal of Korean Society of Forest Science
• /
• v.104 no.3
• /
• pp.360-367
• /
• 2015

The present study investigated the habitats of Korean fir trees (Abies koreana E. H. Wilson) on Mt. Baekwun (Baekwun-san), determined the current distribution, quantified the contribution of biological and non-biological environmental factors affecting the distribution, derived actual and potential habitats, presented a plan for the establishment of protected areas, applied RCP 8.5 climate change scenario to analyze the effects of climate change on the future distribution of Korean fir trees, and predicted future potential habitats. According to the results of the study, 3,325 Korean fir trees (DBH >= 2.5 cm) inhabited Mt. Baekwun, and their distribution area was approximately 150 ha. Populations of Korean fir trees were confirmed to exist at an altitude of 900 m above sea level and were distributed up to 1,200 m. Based on potential distribution, areas appropriate for habitation by Korean fir trees were analyzed to be 450 ha, three times the current distribution area, with a focus on Sang Peak (Sang-bong), Eokbul Peak (Eokbul-bong), Ddari Peak (Ddari-bong), and Dosol Peak (Dosol-bong). The forest stands near Sang Peak, the main peak, were evaluated as those with the most appropriate potential for the habitation of Korean fir trees, and populations of the trees tended to prefer the northern slope rather than the southern slope. When climate change scenario RCP 8.5 was applied and future potential distribution was analyzed, the habitats were expected to decrease in area to 20 ha by 2050, with a focus on Sang Peak, and areas appropriate for habitation were predicted not to exist by 2080. Judging from such results, as global warming accelerates, the habitats of Korean fir trees are clearly expected to move from lowlands to highlands.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.6
• /
• pp.955-961
• /
• 2014

This study was carried out to investigate the amounts of vitamin C in 22 sweet potato cultivars cultivated in Korea as well as evaluate the effects of cooking methods on vitamin C contents. Methods for determining vitamin C was validated by determining linearity, specificity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using HPLC. Results showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The LOD and LOQ values for ascorbic acid (AA) were 0.03 and $0.10{\mu}g/mL$, respectively. The relative standard deviations (RSDs) for intra- and inter-day precision of AA were less than 5%. The recovery rates of AA and dehydroascorbic acid (DHA) were in the range from 98.21~98.64 and 98.28~100.68%, respectively. Depending on cultivar, contents of AA, DHA, and total ascorbic acid (TA) in sweet potatoes varied in the range from 37.76 (Sinyulmi)~89.25 (Juhwangmin), 23.37 (Sinjami)~63.94 (Sinyulmi), and 68.52 (Sinjami)~115.95 (Juhwangmin) mg/100 g, respectively, and their average levels were $56.98{\pm}12.53$, $36.46{\pm}9.03$, and $93.44{\pm}12.00mg/100g$, respectively. The average TA levels were also dependent on flesh color, whish was significantly higher in general sweet potato and orange sweet potato than in purple sweet potato. Steaming, baking, and frying processes significantly reduced AA (10.61~58.41%), DHA (2.57~52.81%), and TA (14.54~49.92%) contents in sweet potatoes. The highest reduction of AA, DHA, and TA contents was observed after baking, followed by steaming and frying. We expect that the basic information provided by this study will be useful to plant breeders and food scientists.

• The korean journal of orthodontics
• /
• v.26 no.5 s.58
• /
• pp.497-507
• /
• 1996

The aim of present study in vitro was to evaluate and compare the effects of different washing times of enamels etched with low phosphoric acid solution which makes unsoluble salts and etched but contaminated with saliva on shear bond strength of an orthodontic adhesive to enamel, and to observe the washing effect on the etched enamel surface by scanning electron microscope. All brackets were bonded with Mono-$Lok2^{TM)}$) on the labial surface of extracted human bicuspids after etching with $20w/w\%\;and\;37w/w$ and phosphoric acid solution for 60seconds and then washing for 0,5,10 and 20seconds respectedly. After etching with $37w/w\%$ phosphoric acid solution and contaminating with saliva for 30seconds and then washing for 0,5,20 and 30seconds and re-etching for 10seconds. After 24hours passed in the $37^{\circ}C$ water bath, the shear bond strengths were measured on Universal Test Machine. The data were evaluated and tested by ANOVA and Duncan's multiple range test, and those results were as follows. 1. There was no significant differences between (p>0.05) shear bond strength of bonded brackets with 5, 10, 20seconds washing etched enamel using $37{\%}w/w{\%}$ phosphoric acid solution. 2. The shear bond strength of bonded brackets with $20w/w\%$ phosphoric acid and then washing for 5seconds showed bonded strength durable to occlusal force but its coefficiency score was high and etched surface was not cleaned completely and therefore it was assumed that its clinical application is not applicable. 3. There was no significant differences between (p>0.05) shear bond strengths of bonded brckets with washing for 5seconds etched enamel using $37w/w\%$ phosphoric acid solution and 10,20 seconds washing etched enamel using $20w/w\%$ phosphoric acid solution. 4. The shear bond strength of washing for 5seconds etched enamel which was contaminated with saliva showed sufficient bonded strength durable to occlusal force but its coefficiency score was high and therefore its clinical application was not applicable. 5. After etching, the sample contaminated with saliva showed the sufficient shear bond strength even washing 20seconds without re-etching.

• The korean journal of orthodontics
• /
• v.33 no.4 s.99
• /
• pp.279-291
• /
• 2003

Electric current is a highly probable way as a clinical tool for tooth movement. The purposes of this study were to determine the usefulness of exogenous electric currents in accelerating orthodontic tooth movement and to investigate the effects of electric-orthodontic treatment on the remodeling of the periodontal tissue histologically The study was performed with six male cats weighing around 3kg. The electric device wich is providing the direct electric current of $20{\mu}A$ was inserted to the removable appliance. The right and left maxillary canines were assigned as control and experimental sides respectively. The control canine was Provided with orthodontic force (75gm) oかy and the experimental side was given the same amount of force and electricity. The lingual buttons were bonded to the maxillary canines and both sides of canines were retracted with NiTi coil spring. The electric device was adjusted to provide 20uh direct current to the experimental canines S hours a day The amount of the canine movement was measured with electronic caliper every week. After 4 weeks of tooth movement, the animals were sacrificed and the histologic study was performed. The results of this study were as follows. 1. The application of a direct current to the experimental tooth significantly increased the final amount of orthodontic tooth movement. The amount of tooth movement after 28-day was 37% more in the experimental side. 2. The electrically stimulated tooth showed histologic evidence of significant increases in the amount of bones and matrix deposition in the area of tension. 3. In the compression side, the electric-orthodontic treatment stimulated bone resorption more extensively in the experimental canines. 4. After 28 days of electricity exposure and orthodontic force, the experimental side demonstrated significantly more osteoblasts, osteoclasts, capillaries and osteoid tissues, reflectinr an increase in the local tissue's cellular activity. 5. Intermittent electrical stimulation (five hours a day) had effects to enhance orthodontic tooth movement and tissue remodeling. These results suggested that the low-intensity exogenous electric current by the miniature electric device might accelerate orthodontic tooth movement and bone remodeling in vivo and have the possibility to reduce the orthodontic treatment duration.

• Progress in Medical Physics
• /
• v.21 no.2
• /
• pp.145-152
• /
• 2010

Inveon PET is a recently developed preclinical PET system for small animal. This study was conducted to measure the performance of Inveon PET as recommended by the NEMA NU 4-2008. We measured the spatial resolution, the sensitivity, the scatter fraction and the NECR using a F-18 source. A 3.432 ns coincidence window was used. A $1\;mm^3$ sized F-18 point source was used for the measurement of spatial resolution within an energy window of 350~625 keV. PET acquisition was performed to obtain the spatial resolution from the center to the 5 cm offset toward the edge of the transverse FOV. Sensitivity, scatter fraction, and NECR were measured within an energy window of 350~750 keV. For measuring the sensitivity, a F-18 line source (length: 12.7 cm) was used with concentric 5 aluminum tubes. For the acquisition of the scatter fraction and the NECR, two NEMA scatter phantoms (rat: 50 mm in diameter, 150 mm in length; mouse: 25 mm in diameter, 70 mm in length) were used and the data for 14 half-lives (25.6 hr) was obtained using the F-18 line source (rat: 316 MBq, mouse: 206 MBq). The spatial resolution of the F-18 point source was 1.53, 1.50 and 2.33 mm in the radial, tangential and axial directions, respectively. The volumetric resolution was $5.43\;mm^3$ in the center. The absolute sensitivity was 6.61%. The peak NECR was 486 kcps @121 MBq (rat phantom), and 1056 kcps @128 MBq (mouse phantom). The values of the scatter fraction were 20.59% and 7.93% in the rat and mouse phantoms, respectively. The performances of the Inveon animal PET scanner were measured in this study. This scanner will be useful for animal imaging.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.3
• /
• pp.339-344
• /
• 2012

This study was performed to investigate the effect of germinated Ilpum rough rice extract on blood glucose in C57BL/KsJ-db/db mice. The mice were divided into several groups: normal control (NC), diabetic control (DC), those fed with 0.25% germinated Ilpum rough rice extract (DM-0.25%GIRRE), those fed with 0.5% germinated Ilpum roughrice extract (DM-0.5%GIRRE) and those fed with 1% germinated Ilpum rough rice extract (DM-1%GIRRE). After 8 weeks of treatment, body weight, water intake, and diet intake of the DM-1%GIRRE group were significantly lower than the other DM groups. Blood glucose levels of the DM-1%GIRRE group were significantly lower compared to the DC group. Fasting blood glucose HbA1c level and total glucose tolerance test were significantly lower in the DM-1%GIRRE groups compared to the DC group. There was no significant difference in serum insulin level among each group. Therefore, the results of this study demonstrate that germinated Ilpum rough rice extract alleviates many of the symptoms of diabetes in genetically obese mice and may offer a possibility as a therapeutic supplement for the normalization of blood glucose levels in humans with hyperglycemia. It may also have beneficial effects in patients with non-insulin-dependent diabetes mellitus.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.3
• /
• pp.333-338
• /
• 2012

The effects of ethanol extract from leaves of Eleutherococcus senticosu were evaluated on hyperlipidemic rats. Male SD rats were divided into a normal group, control (AIN-76 diet) group, Garcinia cambogia extract group, and AIN-76 diet group supplemented with ethanol extract from Eleutherococcus senticosu (EEES). The body weight of the AIN-76 group increased, whereas those of the Garcinia and EEES groups decreased. The serum total cholesterol of the AIN-76 group increased by 28.36% compared to the normal group, but decreased by only 27.15% in the Garcinia group and 25.47% in the EEES group. The serum triglyceride level of the AIN-76 group increased by 35.04% compared to the normal group, but decreased by only 26.76% in the Garcinia group and 37.54% in the EEES group. The serum HDL-cholesterol levels of the Garcinia and EEES groups increased compared to that of the AIN-76 group. The liver and epididymal adipose tissue weights of the EEES group decreased compared to those of the AIN-76 group. In measuring the concentration of triglycerides and total cholesterol level in the liver extracts, the AIN-76 group showed significant increases compared to the normal group, whereas the Garcinia and EEES groups showed a significant decrease compared to the AIN-76 group. These results indicate that the EEES group may improve lipid metabolism and reduce fat accumulation and body weight.