• Imaging Science in Dentistry
• /
• v.39 no.3
• /
• pp.121-132
• /
• 2009

Purpose : To investigate the effects of 2-deoxy-D-glucose (2-DG) and quercetin (QCT) on gene expression of bone sialoprotein (BSP) and osteocalcin (OC) during the differentiation in irradiated MC3T3-E1 osteoblastic cells. Materials and Methods : When MC3T3-E1 osteoblastic cells had reached 70-80% confluence, cultures were transferred to a differentiating medium supplemented with 5 mM 2-DG or $10{\mu}M$ QCT, and then irradiated with 2, 4, 6, and 8 Gy. At various times after irradiation, the cells were analyzed for the synthesis of type I collagen, and expression of BSP and OC. Results : The synthesis of type I collagen in cells exposed to 2 Gy of radiation in the presence of 2-DG or QCT showed no significant difference compared with the control group within 15 days post-irradiation. When the cells were irradiated with 8 Gy, 2-DG facilitated the irradiation mediated decrease of type I collagen synthesis, whereas such decrease was inhibited by treating with QCT. During MC3T3-E1 osteoblastic cell differentiation, the mRNA expression of BSP and OC showed the peak value at 14 days and 21 days, respectively. 2-DG or QCT treatment alone decreased the level of BSP mRNA, but increased the OC mRNA level only at early time of differentiation (day 7). In the cells irradiated with 2, 4, 8 Gy, the mRNA expression of BSP and OC decreased at 7 days after the irradiation. The cells were treated with various dose of radiation in the presence of 2-DG or QCT, the mRNA level of both BSP and OC increased although this increase was observed at low dose of radiation (2 Gy) and at the early stage of differentiation. However, when the cells were exposed to 4, 6, or 8 Gy, the increase of BSP and OC mRNAs was detected only in cells co-incubated with QCT. Conclusion : This study demonstrates that 2-DG and QCT affect differently the expression of bone formation related factors, type I collagen, BSP, and OC in the irradiated MC3T3-E1 osteoblasic cells, according to the dose of radiation and the times of differentiation. Overall, the present findings suggest that 2-DG and QCT could have the regulatory roles as radiation-sensitizer and -protector, respectively.

• Culinary science and hospitality research
• /
• v.19 no.3
• /
• pp.142-155
• /
• 2013

This study investigates perilla seed powder substituted for wheat flour in bread recipes with the amounts of 0%(control), 5%, 10%, 15%, and 20%. Perilla seed powder consists of 9.41% of moisture content, 9.14% of crude protein, 1.12% of crude fat, and 2.97% of crude ash. Sedimentation value and pelshenke value have decreased as the perilla content increased. The farinograph measurement result of the bread made with perilla seed powder showed that consistency, water absorption and tolerance index have increased as the perilla content increased. The amylograph measurement result of the bread made with perilla seed powder showed that T, P, H, F, P-H and F-H have decreased as the perilla content increased. Baking loss and specific loaf volume have decreased as the perilla content increased. The chromatic 'L' and 'b' values were reduced as more perilla was added to more pan bread, while the chromatic 'a' value increased. The texture measurement result showed that the hardness of bread have increased as the ingredient contents increased. Their cohesiveness, spinginess, and chewiness have decreased as the ingredient contents increased. Overall preference scores showed a high preference for the bread made with 15% perilla seed powder.

• Carbon letters
• /
• v.23
• /
• pp.38-47
• /
• 2017

In this study, magnetite ($Fe_3O_4$) nanoparticles were electrochemically synthesized in an aqueous electrolyte at a given potential of -1.3 V for 180 s. Scanning electron microscopy revealed that dendrite-like $Fe_3O_4$ nanoparticles with a mean size of < 80 nm were electrodeposited on a glassy carbon electrode (GCE). The $Fe_3O_4/GCE$ was utilized for sensing chloramphenicol (CAP) by cyclic voltammetry and square wave voltammetry. A reduction peak of CAP at the $Fe_3O_4/GCE$ was observed at 0.62 V, whereas the uncoated GCE exhibited a very small response compared to that of the $Fe_3O_4/GCE$. The electrocatalytic ability of $Fe_3O_4$ was mainly attributed to the formation of Fe(VI) during the anodic scan, and its reduction to Fe(III) on the cathodic scan facilitated the sensing of CAP. The effects of pH and scan rate were measured to determine the optimum conditions at which the $Fe_3O_4/GCE$ exhibited the highest sensitivity with a lower detection limit. The reduction current for CAP was proportional to its concentration under optimized conditions in a range of $0.09-47{\mu}M$ with a correlation coefficient of 0.9919 and a limit of detection of $0.09{\mu}M$ (S/N=3). Moreover, the fabricated sensor exhibited anti-interference ability towards 4-nitrophenol, thiamphenicol, and 4-nitrobenzamide. The developed electrochemical sensor is a cost effective, reliable, and straightforward approach for the electrochemical determination of CAP in real time applications.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.7
• /
• pp.1035-1040
• /
• 2005

This study was conducted to investigate the surface spraying effect of materials on the rheological properties of frozen starch with microwave heating. Microwave helps reduce cooking time by high temperature, but swiftly snatches moisture from foods such as frozen starches (buns and noodles etc) and makes surface of foods harder. Four types of maltodextrin materials have been prepared for different concentration solutions and sprayed on surface doughs of sheet type. Sprayed dough samples were Quickly frozen at $-70^{\circ}C$ and wrapped with polypropylene film. All the treated samples were kept at 0, -20 and $-50^{\circ}C$, and then taken out periodically for measurement of the quality during storage. The quality attributes evaluated after heating with microwave energy include sensory quality retrogradation, texture, surface color and microstructure. The quality of frozen starches deteriorated with long term storage even at low temperatures of -20 and $-50^{\circ}C$, and the spray materials were found to improve the textural and physical properties of frozen starches in the microwave heating. Particularly, maltodextrin with D.E value of $9\~12$ had the most desirable effects of quality improvement.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.4
• /
• pp.533-538
• /
• 2012

The retrogradation properties of a Korean rice cake ($Karedduk$) added with oligosaccharides after 0~30 hr of storage at $5^{\circ}C$ were examined by texture profile analysis and the Avrami equation using textural characteristics. Oligosaccharides, such as galactooligosaccharide (50%) and maltooligosaccharide, were added to dry rice flour at levels of 10%. In the amylogram, the breakdown (P-H) and consistency (C-H) of the Korean rice cake (Karedduk) added with oligosaccharides were lower than those of the control. Texture profile analysis using a Texture Analyzer revealed that the hardness of the Korean rice cake ($Karedduk$) added with oligosaccharides was lower than the control. The Avrami exponent ($n$) for the control, galactooligosaccharide (50%) 10% and maltooligosaccharide 10% addition was 2.415, 2.771 and 2.683, respectively. The time constant (1/$k$) for galactooligosaccharide (50%) 10% or maltooligosaccharide 10% addition was higher than the control. Overall, adding galactooligosaccharide (50%) 10% or maltooligosaccharide 10% to a Korean rice cake ($Karedduk$) is effective in retarding retrogradation.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.15 no.3
• /
• pp.93-98
• /
• 2005

The crystal growth of calcite at a low temperature range was carried out by the hydrothermal method using amorphous calcium carbonate which has excellent solubility in water. Amorphous calcium carbonate was prepared by the wet chemical reaction of a stoichiometric mixture of $CaCl_2\;and\;Na_2CO_3$. An important factor was the reaction temperature and time taken in preparation of the amorphous calcium carbonate. From the solubility results calculated by the weight loss method, $NH_4NO_3$ solutions were found to be the most promising solvents to grow calcite single crystals. The hydrothermal conditions for high growth rates of calcite single crystals were as follows: starting material: amorphous calcium carbonate, solvent: 0.01 m $NH_4NO_3$, temperature: $180^{\circ}C$, duration: 30 days. And properties of calcite single crystals were follows: dislocation density: $10^6{\sim}10cm^{-2}$, UV-visible transmittance: about 80% from 190 to 400 nm and birefringence: $0.17{\sim}0.18$. Also, it can be known from the FT-IR results that the absorption peak by injection of $HCO_3^-\;and\;OH^-$ ions was not shown.

• Journal of the Korean Society of Safety
• /
• v.24 no.6
• /
• pp.63-71
• /
• 2009

In order to improve flame retardancy, the halogen free organic melamine phosphate(M-P) flame retardant was synthesized from melamine and phosphoric acid by the reaction of precipitation. The ignition test was carried out preparing hybrid flame retardant compound($H_bFRC$) consisting of organic M-P and inorganic Mg$(OH)_2$ as a flame retardant in the polyolefin resins. The flame retardancy and mechanical properties of flame retardant aluminum composite panel($H_bFRC$-ACP) were performed to investigate the possibility of the composite material, which was contained M-P, as a inner core for $H_bFRC$-ACP. For this study, the results of ignition test indicate that a char formation and drip suppressing effect, and combustion time reduced as the content of M-P increased. The limited oxygen index(LOI) values were measured 17.4vol% and 31.5vol% for LDPE only and $H_bFRC$-3(M-P content: 15wt%), respectively. And it was verified that the $H_bFRC$-3 was needed more oxygen quantity with the increase of M-P content when it combustion. Also, the results from thermogravimetric analysis were observed endothermic peak at $350^{\circ}C$ and $550^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by the mixture of M-P and Mg$(OH)_2$. The LDPE-ACP (using only LDPE as a inner core), $35.13kW/m^2$ of heat release rate(HRR) and 13.43MJ/m2 of total heat release(THR) were measured while the $H_bFRC$-ACP, $10.44kW/m^2$ of HRR and 1.84MJ/m2 of THR were measured by results of cone calorimeter test. In case of $H_bFRC$-ACP, the average gas emission amount of CO and $CO_2$ could be decreased down to 25% and 20%, respectively, in comparison with LDPE-ACP. The mechanical properties such as tensile strength, bending strength and adhesion strength of $H_bFRC$-ACP were revealed slightly high values $54N/mm^2$, $152N/mm^2$ and 120N/25mm, respectively, compared with LDPE-ACP. It was confirmed that flame retardancy was improved with the synergy effect because of char formation by M-P and hydrolysis by Mg$(OH)_2$. The result of this study suggest that $H_bFRC$ can be applied for an adequate halogen free flame retardant composite material as a inner core for ACP.

• Korean Chemical Engineering Research
• /
• v.49 no.6
• /
• pp.775-780
• /
• 2011

5-cell DMFC stack was fabricated and operated with the load of 4 A for 4000 hrs. After 4000 hrs operation peak power density of the stack reduced by 27.3%. Two of the five cells did now show performance degradation, the performance of other two was reduced by 40% and the performance of the other decreased by 60%. The amount of performance degradation of each cell by long-term operation did not correlate with the position in the stack. Platinum particle size in the anode catalyst layer of the MEA with the strongest degradation increased and the increase was severer on the position of methanol inlet than on the position of methanol outlet. However, platinum particle size in the cathode catalyst layers did not changed for all the MEA'. Ruthenium crossover from the anode catalyst layer to the cathode catalyst layer through the membrane was observed after 4,000 hrs operation by SEM-EDX and it occurred for all MEA' regardless of the degree of performance degradation. Atomic ratio of ruthenium to platinum in the cathode catalyst layer was the highest in the MEA with the strongest performance degradation.

• Korean journal of applied entomology
• /
• v.17 no.1 s.34
• /
• pp.41-47
• /
• 1978

Pheromones of several insect species were evaluated in a screening program in terms of their usefulness in pest forecasting and control in Korea. Species included striped rite borer (Chilo suppressalis) and tortricid moths, which attack deciduous fruit, and colding moth. The pheromone of striped rice borer was supplied through the courtesy of the Tropical Products Institute, London. Pheromones of other species were obtained from Cornell University and the Zoecon Corporation of Palo Alto, California. 'rho results of this experiment were as follows: 1. Live traps containing virgin striped rice borer female moths were more effective in attracting male moths than were the pheromone traps. 2. Since the effectiveness of the striped rice borer pheromone decreased dramatically with time, it was difficult to estimate the peak tine of the borer emergence. 3. The primary species trapped in deciduous fruit orchards was the oriental fruit moth, Grapholitha molesta. The traps were baited with the phermones, OFM and LAW. 4. Several moth species were trapped with OBLR. RBLR. SPAR and ArcM phermones but few were trapped with the remaining eight tortricid pheromones. 5. The following tortricid pheromones might be useful for forecasting the species given: OFM, LAW : Grapholitha molesta OBLR : Archips breviprecanus OBLH, RBLR, ArcM : Archippus coreensis Archips fuscocupreanus Hoshinoa longicellana SPAR, TBM ; Phyroderces sp.

• Korean journal of applied entomology
• /
• v.56 no.4
• /
• pp.365-370
• /
• 2017

The flowering season of jujube (Zizyphus jujuba var. inermis (Bunge) Rehder) is overlaps with the rainy season and the abnormal weather conditions in Korea, thereby affecting pollination, fertilization, and fruit setting. We studied the pollinating activities of Apis mellifera L. and Bombus terrestris L. in rain shelter houses and their effects on fruit setting, with the ultimate aim of stabilizing fruit setting in Z. jujuba. A. mellifera and B. terrestirs were used for pollination in jujube orchard in the rain shelter house for approximately 55 days from June 1, 2016, to July 25, 2016. The peak time of the rate of outgoing and incoming A. mellifera was recorded in the afternoon. However, the diurnal activity of B. terrestris was constant between 09:30 and 17:30 h. The rate of jujube fruit set on current shoots by A. mellifera and B. terrestirs was 10.2 and 8.9%, whereas that in plots with no pollinators was 5.5%. Therefore, using pollinator in the rain shelter house in jujube orchard is effective in promoting jujube fruit setting.