• Childhood Kidney Diseases
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• v.12 no.1
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• pp.88-92
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• 2008

Infection of Epstein-Barr virus(EBV) gives rise to a broad spectrum of clinical manifestations in children. Although renal involvement is rare, diverse renal manifestations are known from hematuria to acute renal failure. Secondary membranous nephropathy(MN) associated with systemic EBV infection is an uncommon renal pathology and only two cases have been reported. We are adding another case of MN associated with EBV infection in a child. An 8-year-old girl was admitted for renal biopsy. She had been followed up for microscopic hematuria and intermittent proteinuria for 5 months. There had been no specific findings in serology and radiology. Tonsil biopsy had been done due to exudative tonsillar hypertrophy and enlarged multiple cervical lymph nodes. And it showed EBV-associated lymphoproliferative findings. Serologic tests for EBV showed positive evidence of recent infection; viral capsid antigen(VCA) IgM was borderline positive, VCA IgG and early antigen IgG were positive, and EB nuclear antigen IgG was negative. In Situ Hybridization of tonsil for EBV mRNA was positive. Because her proteinuria and hematuria were aggravated at that time(protein 3 +, RBC >60/HPF), renal biopsy was done. Renal biopsy showed the findings of MN, characterized by thickened capillary walls with epimembranous spikes on light microscopy and subepithelial, mesangial and subendothelial electron dense deposits on electron microscopy. On immunofluorescence microscopy, IgG, C1q, kappa and lambda chains were positive. After steroid administration, proteinuria and hematuria resolved gradually within 6 months.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.183-187
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• 1973

Soong-Neung is a Korean traditional beverage served after meals and is made from Soong-Neung producing rice (Noo-Roon-Bap) which is cooked and toasted rice produced on the bottom of the container during the rice cooking process. In order to study the chemical changes occurring in Soong-Neung producing rice with temperature$(20{\sim}220^{\circ}C)$ during the cooking process, thermal analysis, total sugars, total nitrogen, reducing sugars, water soluble nitrogen, total acid, carbonyl content, phenolic compounds were determined. Thermal analysis showed that decrease of weight and endothermic reaction caused by evaporation of water in the sample appeared at $95{\sim}130^{\circ}C.$ The production of volatile compounds increased gradually beginning at $130^{\circ}C$, however, those compounds increased markedly at $160^{\circ}C$ and above. Maximum absorption of ultraviolet spectra of an aqueous distillate occurred at about $273m{\mu}$. Organoleptic analysis showed that an acceptable flavor was produced in the temperature range of $125{\sim}155^{\circ}C.$

• Korean Journal of Materials Research
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• v.13 no.6
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• pp.347-351
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• 2003

II-Ⅵ ZnO compound semiconductor thin films were grown on $\alpha$-Al$_2$O$_3$(0001) single crystal substrate by radical beam assisted molecular beam epitaxy and the optical properties were investigated. Zn(6N) was evaporated using Knudsen cell and O radical was assisted at the partial pressure of 1$\times$10$^{4}$ Torr and radical beam source of 250-450 W RF power. In $\theta$-2$\theta$ x-ray diffraction analysis, ZnO thin film with 500 nm thickness showed only ZnO(0002)and ZnO(0004) peaks is believed to be well grown along c-axis orientation. Photoluminescence (PL) measurement using He-Cd ($\lambda$=325 nm) laser is obtained in the temperature range of 9 K-300 K. At 9 K and 300 K, only near band edge (NBE) is observed and the FWHM's of PL peak of the ZnO deposited at 450 RF power are 45 meV and 145 meV respectively. From no observation of any weak deep level peak even at room temperature PL, the ZnO grains are regarded to contain very low defect density and impurity to cause the deep-level defects. The peak position of free exciton showed slightly red-shift as temperature was increased, and from this result the binding energy of free exciton can be experimentally determined as much as $58\pm$0.5 meV, which is very closed to that of ZnO bulk. By van der Pauw 4-point probe measurement, the grown ZnO is proved to be n-type with the electron concentration($n_{e}$ ) $1.69$\times$10^{18}$$cm^3$, mobility($\mu$) $-12.3\textrm{cm}^2$/Vㆍs, and resistivity($\rho$) 0.30 $\Omega$$\cdot$cm.

• Applied Biological Chemistry
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• v.39 no.4
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• pp.304-308
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• 1996

The major color component of a Korean pigmented rice (Oeyza sativa var. Suwon 415) was purified with Amberlite XAD-7 column and preparative paper chromatography. The purified pigment was determined as anthocyanin by paper chromatography, UV/Vis and NMR spectroscopy. The $\lambda_{max}$ of the Purified anthocyanin on UV/Vis spectrum were 529 nm and 281 nm. The $A_{440}/A_{529}$ value of the purified anthocyanin was 23% suggesting the presence of 3-glycosidic structure. The aglycone from acid hydrolysis showed bathochromic shift (18 nm) in the presence of $AlCl_3$ indicating that the anthocyanidin contained free adjacent hydroxyl groups such as cyanidin, delphinidin, petunidin or luteolinidin. The sugar moiety obtained from acid hydrolysis was determined as glucose by paper chromatography. The NMR spectra showed that the aglycone was cyanidin and the sugar was ${\beta}-D-glucopyranose$. Thus, the chemical structure of the purified anthocyanin was identified as cyanidin $3-O-{\beta}-D-glucopyranoside$.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.7
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• pp.552-561
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• 2016

In this experimental study, the dynamic stability derivatives of a tailless lambda-shape UAV are estimated from time history data of aerodynamic moments measured from the internal balance while the test model is forced to oscillate at given frequencies and amplitudes. A 3-axis forced oscillation apparatus is designed to induce decoupled roll, yaw, pitch oscillations respectively. The results show that the roll damping derivatives remain stable at the entire range of angle of attack tested, whereas the pitch damping derivatives become unstable beyond $15^{\circ}$ angle of attack. The amplitude and frequency have little impact on roll damping derivatives while the smaller amplitude and frequency of oscillation improves the pitch stability. The yaw damping derivative values are fairly small as expected for a tailless configuration. The results indicate that the proposed methodology and test apparatus area valid for estimating the dynamic stability derivatives of a tailless UAV.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.105-111
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• 1995

The relationship betwwen the molecular structure of amylopectin and the texture of cooked rice was investigated using Korean rice [3 varieties of Japonica type and 3 varieties of Tongil type(Japonica-Indica breeding type)]. The molecular structure of rice amylopectin was polymodal and distributed A chain of $\overline{DP}$ 12.4, short B chain of $\overline{DP}$ 20.6, B chain of $\overline{DP}$ 26.3, long B chain of $\overline{DP}$ 45 and super long chain of above $\overline{DP}$ 55. The super long chain of amylopectin was composed of long linear chain with poorly branched chain. Also, the super long chain of amylopectin showed positive correlated with average chain length, inherent viscosity and ${\beta}-amyloysis$ limit$({\%})$, but negative correlated with ${\lambda}max$ of iodine reaction of amylopectin. The structural properties of amylopectin in Japonica type were different from those of amylopectin in Tongil type. In relationship between molecular structure of amylopectin and texture of cooked rice, the average chain length, inherent viscosity, ${\beta}-amyloysis$ limit and super long chain of amylopectin was showed a positive correlation with hardness, but a negative correlation with adhesiveness of cooked rice. The long chain of rice amylopectin is the less, the eating quality of cooled rice was the better. These results suggest that the molecular structure of rice amylopectin could be responsible for the texture of cooked rice.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.503-509
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• 2003

For the development of the anti-obesity natural drug, the inhibitor of adipocyte differentiation was screened from Korean traditional medicinal plants. Phellodendri Cortex was selected as a candidate of adipocyte differentiation inhibitor. An inhibitory compound PC-4 was purified from the methanol (MeOH) extract of Phellodendri Cortex using silica gel and ODS RP-18 column chromatography and HPLC. PC-4 was obtained as yellow powder; UV ${\lambda}_{max}$ (MeOH): 230, 260, 340 and 430 nm. The chemical structure of PC-4 was determined as an isoquionoline alkaloid, berberine, on the basis of various NMR experiments including $^1H-\;and\;^{13}C-NMR$. The PC-4 inhibited the differentiation of preadipocyte NIH-3T3 L1 cells at a concentration of $1\;{\mu}g/mL$.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.603-610
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• 1990

The structural properties of cold water extractable ${\alpha}-D-glucan$ in rice flours obtained by various milling methods were investigated. The blue value, ${\lambda}_{max}$ values of the iodine complex and ${\beta}-amylolysis$ limit of the cold water extractable ${\alpha}-D-glucan$ were in the range of $0.026{\sim}0.030,\;518{\sim}522\;nm$ and $52.7{\sim}59.6%$, respectively, indicating these materials were composed mainly of amylopectin-like polymer. The gel chromatography on Sepharose CL-2B indicated that the cold water extractable ${\alpha}-D-glucan$ had lower molecular weight but wider molecular weight distribution than that of the original rice amylopectin. The Sephadex G-50 gel chromatography showed that the unit chain distribution of cold water extratable ${\alpha}-D-glucan$ after debranching with pullulanase was similar to that of rice amylopectin. And the ion chromatography of the distribution pattern of the chain length below D.P.30 in the debranched ${\alpha}-D-glucan$ indicated only blade-milled flour was similar to the amylopectin, but in the amount of unit chain below D.P.10, all the ${\alpha}-D-glucan$ in rice flours was higher than that of amylopectin.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.504-510
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• 1988

The physicochemical properties of rice flours which were obtained by dry milling(blade, hammer, test and micro mill) and wet & dry milling (roller & micro mill) were investigated. The resulting flour particle sizes were reduced in the order that of blade, hammer, test, micro and roller & micro mill. Scanning electron microscopic examination showed that the starch granules were freed from the imbedding matrix as the particles became finer. The test-milled flour had the hightest levels of starch damage, maltose value and hot-water soluble amylose content, and the blade-milled flour showed the lowest levels. Amylograph viscosity and gelatinization temperature of the flours decreased as the particles became finer, and the addition of $Hg^{+2}$ increased the peak viscosity of the dry-milled flour pastes, whereas the wet & dry-milled flour did not show any changes. The blue values and ${\lambda}$max values of the iodine complex of the cold-water extractable ${\alpha}-D-glucan$ from flours were in the range of 0.023-0.029 and 518-522nm, respectively, indicating these materials were shown to be mainly composed of amylopectin-like polymer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.3 s.106
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• pp.249-258
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• 2006

In this letter, we propose a novel printed helix antenna for RFID reader in UHF band. The printed strip line of the antenna is first wound up outside a polygonal shaped layer and then the winding continues on an inner layer to control the overall gain and the radiation pattern. In addition, the winding pitch angles on each layer have either negative or positive values resulting in the broad CP bandwidth. The detail structure of the antenna was optimized using Pareto genetic algorithm(GA), so as to obtain excellent performances for RFID reader antennas. The optimized two-layered polygonal helix was fabricated on the cardboard of a flexible substrate and the performances were measured and compared with the simulations. The fabricated antenna was made up of copper tape which can adhere to a flexible cardboard and had 21.4 % matching bandwidth, 31.9 % CP bandwidth, readable range of $5.5m^2$ with kr=3.2. Also based on the current distribution of the strip line of the antenna and sensitivity of the antenna bents points, we confirmed that the antenna has the quarter-wave transformer near the feed for the broad matching bandwidth and radiates the traveling wave for the broad CP bandwidth using the bent strip line.