• Journal of Photoscience
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• v.12 no.1
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• pp.17-23
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• 2005

Application of a new photocatalyst has been attempted to improve the efficiency and rates of photocatalytic degradation of azo dyes by using a model dye such as Methyl Orange. As a new photocatalyst, $TiO_2$ encapsulated EFAL-removed zeolite Y ($TiO_2$ /EFAL-removed zeolite Y) has been synthesized by ion-exchange in the mixture of EFAL-removed zeolite Y with 0.05 M aqueous [$(NH_4)_2 TiO(C_2O_4)_2.H_2O$] [$TiO(C_2O_4)_2.H_2O$]. This new photocatalyst has been characterized by measuring XRD, IR and reflectance absorption spectra as well as ICP analysis, and it was found that the framework structure of $TiO_2$ /EFAL-removed zeolite Y is not changed by removing the extra-framework aluminum (EFAL) from the normal zeolite Y and the $TiO_2$ inside the photocatalyst exists in the form of $(TiO^{2+})_n$ nanoclusters. Based on the ICP analysis, the Si/Al ratio of the $TiO_2$ /EFAL-removed zeolite Y and the weight of $TiO_2$ were determined to be 23 and 0.061g in 1.0g photocatalyst, respectively. It was also found that adsorption of the azo dye in the $TiO_2$ /EFAL-removed zeolite is very effective (about 80 % of the substrate used). This efficient adsorption contributes to the synergistic photocatalytic activities of the $TiO_2$ /EFAL-removed zeolite by minimizing the required flux diffusion of the substrate. Thus, the photocatalytic reduction of methyl orange (MO) was found to be 8 times more effective in the presence of $TiO_2$ /EFAL-removed zeolite Y than in the presence of $TiO_2$ /normal zeolite Y. Furthermore, the photocatalytic reduction of MO by using 1.0 g of the $TiO_2$ /EFAL-removed zeolite Y containing 0.061g of $TiO_2$ is much faster than that carried out by using 1.0 g of Degussa P-25.

• Journal of Preventive Medicine and Public Health
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• v.39 no.4
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• pp.317-324
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• 2006

Objectives: This study was conducted to estimate the unbiased smoking prevalence and its standard errors among adolescents in a large city in Korea, by design-based analysis. Methods: All the students in Daegu city were stratified by grade, gender and region, and then schools as primary sampling units (PSU) were selected by probability proportional to size (PPS) sampling. One or two classes were sampled randomly from each grade, from 5th grade in elementary schools to the 3rd grade in high schools. The students anonymously completed a standardized self-administered questionnaire from October to December 2004. The total number of respondents was 8,480 in the final analysis, excluding the third graders in the general high schools because of incomplete sampling. The sampling weight was calculated for each student after post-stratification adjustment, with adjustment being made for the missing cases. The data were analyzed with Stata 8.0 with consideration of PSU, weighting and the strata variables. Results: The smoking prevalence (%) and standard errors for male students from the fifth grade in elementary schools to the second grade in high schools were $0.93{\pm}0.47,\;1.83{\pm}0.74,\;3.16{\pm}1.00,\;5.12{\pm}1.02,\;10.86{\pm}1.13,\;15.63{\pm}2.44\;and\;17.96{\pm}2.67$, and those for the female students were $0.28{\pm}0.28,\;1.17{\pm}0.73,\;3.13{\pm}0.60,\;1.45{\pm}0.58,\;3.94{\pm}0.92,\;8.75{\pm}1.86\;and\;10.04{\pm}1.70$, sequentially. Conclusions: The smoking prevalence from this study was much higher than those from the other conventional studies conducted in Korea. The point estimates and standard errors from the design-based analysis were different from those of the model-based analysis. These findings suggest the importance of design-based analysis to estimate unbiased prevalence and standard errors in complex survey data and this method is recommended to apply to future surveys for determining the smoking prevalence for specific population.

• Korean Journal of Pharmacognosy
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• v.28 no.4
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• pp.215-224
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• 1997

Gamijiyu-tang (GJT) described originally in the Dong Eui Bo Gam, a traditional reference for oriental medicine in the Korea, has been clinically used for treatment of chronic liver disease. In order to evaluate scientifcally a hepatoprotective effect of GJT in the liver fibrotic disease, the present study investigated how GJT improves a hepatic function in the dimethylnitrosamine (DMN)-treated rat. DMN treatment caused a significant increase of relative liver weight to the body at 28 days after DMN induction. Administration of with a clinical dose decreased significantly the sAST level $(158.8{\pm}7.76\;IU/L)$ elevated by DMN in jection (p<0.01). A similar phenomenon was also observed at change of both Salt and Salt level in the GJT and/or DMN-treated animal (p<0.01, p<0.05, respectively). A remarkable increase of hydroxyproline was observed by treatment of DMN with comparing to the normal rat $(361.9{\pm}7.35\;vs.\;1278.1{\pm}52.9\;{\mu}g/g\;tissue,\;p<0.01)$. This was significantly reduced by a simultaneous treatment of GJT with DMN for 21 days (p<0.05), but not recovered completely to its normal value. In addition. GJT administration ameliorated conspicuously the DMN-induces histopathological changes of liver such as hemorrhage. Cell necrosis and fibrosis. Tak'en together, results described here demonstrated scientifically in first the medicinal efficacy of GJT by using in vivo animal model, indicating that GJT improves the DMN-induced hepatic injury through reducing an excessive accumulation of collagen and histopathological changes. The decreased collagen content may be a pivotal process for GJT to improve hepatic function in the DMN-induced liver fibrosis. The present study suggests that GJT may be useful for and applicable to the treatment of hepatic fibrosis in chronic liver disease.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.742-748
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• 1998

Experiments have been conducted to investigate synergistic effects and mechanisms of the Alaskan subbituminous coal/polypropylene (PP). Coliquefaction of coal/PP gave the synergistic effect in yields by 17% compared to independent liquefactions of coal or PP at $430^{\circ}C$. To analyse coliquefaction mechanisms, the second and zeroth order kinetic models were developed for coal and PP conversions respectively. When the models were simulated to fit coliquefaction results, those represented results successfully with the correlation coefficient of 0.99. The amount of tetralin needed to liquefy unit mass of coa 1(${\beta}$) was also calculated using the developed model. According to the calculated results, $\beta$ increased from 0.4 to 1.0 as the coliquefaction temperature increased from $410^{\circ}C$ to $470^{\circ}C$. This indicated that tetralin lowered the molecular weight of oil produced, and this phenomenon was recognized by the GPC analyses. Furthermore, it was found that tetralin prohibited the liquefaction of PP when coal was not added. On the other hand, tetralin was believed to act as a hydrogen-donor solvent to coal rather than prohibit PP liquefaction during coliquefaction. Therefore, the liquefaction rate of PP increases and synergistic effects in oil yields are mainly due to the increase in PP liquefaction during coal/PP coliquefaction.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.53-58
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• 2013

The effect of baking on the physicochemical and sensory properties was investigated using a model system of sponge cakes incorporated with pine leaf powder (PLP) as a value-added food ingredient. PLP was incorporated into cake batter at 5 levels (0, 2, 4, 6, and 8%, w/w) by adding an equivalent amount based on the weight of wheat flour. After appropriate mixing, sponge cakes were baked at $170^{\circ}C$ for 30 min in an oven. The baked cakes were cooled to room temperature for 1 h prior to all measurements. The pH, moisture content, specific volume, height, volume index, and symmetry index decreased significantly with the increase in PLP content (p<0.05). On the contrary, specific gravity of the batter and baking loss increased (p<0.05). The lightness of the cakes decreased, whereas redness increased significantly with the higher amount of PLP in the formulation (p<0.05). Hardness also increased significantly (p<0.05). Both total polyphenol content and DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity increased significantly by the addition of PLP (p<0.05). The consumer acceptance test indicated that the addition of PLP up to 4% did not cause a significant unfavorable effect on the consumer acceptances in all attributes. The sponge cakes with 2-4% PLP would be recommended with respect to the overall acceptance score while taking advantage of the functional properties of PLP without sacrificing the consumer acceptability.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.147-151
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• 2006

Effects of wild plant extract (Lak) based on Korea traditional prescription on maximal exercise performance and endurance were evaluated using calorie-restriction animal model. In acute forced swimming test with 10% body weight attached to tail, dietary Lak supplementation increased exercise performance endurance by increasing concentrations of ATP and insulin-like growth factor-1 (IGF-1) under calorie-restriction condition, and decrement of blood lactic acid concentration and increment of muscle ATP content were observed. These results suggest Lak is very effective for decreasing side-effects of obesity therapy using very low calorie diet.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.692-698
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• 2001

This study has been carried out to estimate aboveground biomass and net primary production(NPP) in an average 41-years-old Quercus variabilis stand of Gongju area, 45-years-old Quercus variabilis stand of Pohang area, and 54-years-old Quercus variabilis stand of Yangyang area. Ten sample trees were cut in each forest and soil samples were collected in July to August, 2000. Estimation for aboveground biomass and net primary production were made by the equation model $Wt=aD^b$ where Wt is oven dry weight in kg and D is DBH in cm. Total aboveground biomass was 91.31ton/ha in Gongju area, 207.6ton/ha in Pohang area, and 71.39ton/ha in Yangyang area. The aboveground biomass 207.6ton/ha in Pohang area is the highest biomass production among the amount of biomass in Quercus variabils stands reported in Korea. The proportion of each tree component to total aboveground biomass was high in order of bolewood, bolebark, branches and leaves in the three forests. Aboveground total net primary production was estimated at 7.8ton/ha in Gongju area, 11.5ton/ha in Pohang area, and 6.40ton/ha in Yangyang area. There were at least 2 times higher total aboveground biomass in Pohang area than in the Gongju and Yangyang areas because of climate difference among the study areas.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.98-105
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• 2015

We investigated the effects of a mutan (water-insoluble ${\alpha}$-glucans) isolated from Streptococcus mutans on the healing of bone defect in rat. Sprague-Dawley rats were divided into control (saline-treated), lipopolysaccharide (LPS)-treated, and mutan-treated groups (n=6 per group). Experimental bone defects were surgically created with round fissure bur at the buccal surface of the left mandibular. The control groups was administered with saline solution (0.1 ml/100 g), while the LPS and mutan group was given LPS and mutan (1 mg/kg body weight) three times weekly. After 4 weeks the rats were sacrificed, the healing of bone defect was assessed by bone mineral density (BMD) and micro-computed tomography (${\mu}CT$) examination. Percent bone volume (bone volume/tissue volume [BV/TV]), trabecular thickness (Tb.Th), and trabecular number (Tb.N) parameters of ${\mu}CT$ showed higher values in control group than LPS and mutan group. Bone surface/volume ratio (BS/BV), trabecular bone pattern factor (Tb.Pf), and structure model index parameters of ${\mu}CT$ showed higher values in LPS group than mutan group. BMD values of mutan treated-alveolar bones were significantly lower for than that of the LPS group. Therefore, we suggest that mutan, water-insoluble ${\alpha}$-glucans from S. mutans may be induce the induction of periodontal diseases.