• Journal of Environmental Science International
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• v.8 no.6
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• pp.699-704
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• 1999

The Photodegradation efficient of total organic compounds in the drinking water has been studied using the methods of photocatalytic reaction and laser beam irradation. The results are summarized as follows; 1. The photodegradation efficiency of total organic compounds shows as $50\%\;to\;80\%$ as within one hour and after this the efficiency is decreased slowly. 2. The photodegradation efficiency of total organic compounds shows as 65 to $90\%$ within 3.3min. when Nd : YAG beam is irradiated to the water layer. 3. An excellent observation of the organic compound removal efficiency gives revealed in that case of the longest wavelength of 532nm is irradiated among the three kinds of laser beam sources of 532nm, 355nm and 266nm. 4. The organic compound removal efficiency shows high in the case of UV beam irradiation in the thin layer of water. However the efficiency is not depended on the thickness of water layer severely. 5. The removal efficiency of the organic compounds in the direct irradiation shows higher than the indirect irradiation in the case of UV beam, but the efficiency is not depended on the direction of irradiation in the case of Nd : YAG beam irradiation.

• The Korean Journal of Zoology
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• v.10 no.1
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• pp.17-20
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• 1967

The present experiment was perform to investigate the frequencies of chromosome aberration with special regard to the chromosome groups and the various time intervals after X-irradiation (60 r) in ormal human foetus cells grown in culture. The cytological preparations were prepared at every 5 through 30 hours after X-irradiation by the air-drying method. 1. The frequencies of chormosome aberration are on the whole decreased as tie elapses after irradiation and this is thought to be due to gradual recovery with time . However, a slight increase in frequencies is observed at 25 and 30 hours after irradiation respectively. This shows that the cells at the these periods are more sensitivity to X-irradation , and those cells are thought to be at G$_2$ and late S stage at the time of irradiation respectively, so t is evident that G$_2$ and late S stages a the time of irradiation respectively , so it is evident that G$_2$ and late S stages are more sensitive to X-irradiation than any other stages. 2. The frequencies of chormosome aberration are decreased in descending order of chormosome group number. The differences among these frequencies are highly significant statistically . Therefore it can be concluded that there is a highly significant difference in radiosensitivity among chromosome groups. that is, the chromosomes of the group A are the most radiosensitive , followed by B, C, D ,E and G in descending order.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.325-336
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• 1997

The purpose of this study was to evaluate the compensation effect of exposure duration increase to decreased light intensity of visible-light curing unit. The specimen with 2mm thickness was made of Restorative $Z-100^{TM}$ (A2 shade, 3M Dental Products, U.S.A.) and cured with $Optilux^{TM}$ (Demetron Research Co. U.S.A.). The light intensity was controlled to 420 $mW/cm^2$, 540 $mW/cm^2$, 630 $mW/cm^2$ and curing time, also, controlled to 40, 60, 80 seconds. Cured specimen was stored in a light-proof container for 24 hours to post-irradation was completed. Microhardness of top and bottom surface of specimen were measured to evaluate the depth of cure. The obtained results were as follows: 1. The microhardness of top and bottom surface of the composite resin specimen was increased significantly as light intensity and exposure time was increased (P<0.01). 2. Light intensity was more correlated with bottom microhardness(${\gamma}{\geq}$0.438) than top microhardness(${\gamma}{\geq}$0.213), and exposure time was more correlated with top microhardness (${\gamma}{\geq}$0.424) than bottom microhardness(${\gamma}{\geq}$0.335). 3. The regressive equation was obtained in this study as follows : $H=0.07{\times}D+0.012{\times}I+76$ (H : Microhardness(KHN), D : Exposure time, I : Light intensity)

• Korean Journal of Pharmacognosy
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• v.41 no.4
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• pp.255-263
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• 2010

Kojongsi persimmon (Diospyros kaki) is the major cultivar of astringent persimmon in southern of Korea. Kojongsi persimmon leaf has been traditionally used for acute and chronic diseases in Oriental countries. The purpose of this study was undertaken to investigate the antioxidative activities of the extract of Kojongsi persimmon leaf during growth. We investigated the antioxidant effects of the persimmon leaf extracts during growth on total polyphenol, total flavonoid, electronic donating ability (DPPH), nitrite (NO) scavenging and superoxide dismutase (SOD)-like activity. The next, we investigated the possible cell protective effects of the persimmon extract treatment against ultraviolet B (UVB)-induced injury in HaCaT keratinocytes. The contents of total polyphenol and flavonoid in leaf extract of Kojongsi persimmon were increased in time-dependent manner. In Jun, DPPH and NO radical scavenging and SOD-like activities in the leaf extract of Kojongsi persimmon was increased to the highest. However, the antioxidant activities in persimmon varieties were not any difference. The cell cytotoxicity by UVB irradation in HaCaT keratinocytes was significantly increased with the compared to the control group. However, the treatment of leaf extract of Kojongsi persimmon in HaCaT keratinocytes was shown to protective effect against UVB-induced cell cytotoxicity. These results suggest that the leaf extract of Kojongsi persimmon has potent antioxidant activity, and protective effect against UVB-induced keratinocyte injury. Thus, these properties may be contributed in the care of acute and chronic diseases.

• Journal of radiological science and technology
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• v.12 no.1
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• pp.3-16
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• 1989

In order to investigate the in vivo effect of $^{60}Co$ radiation on rabbit liver, the uptake ratio and regional excretory value in hepatocytes and Kupffer cells were estimated during acute and chronic hepatic injuries. The left lobe of liver was irradiated at 15 Gy or 30 Gy with a single dose and subsequent changes were analysed with a seial nuclear medicine imaging by using $^{99m}Tc-phytate,\;^{99m}Tc-DISIDA\;and\;^{99m}Tc-HSA$ and resulting data were computerized. The degree of hepatic damage, duration of the injury, and recovery pattern after the irradation were in agreement with the findings of other investigations. However, out values were more quantitative evacuation than those of other publications. Recovery of decreased uptake of $^{99m}Tc-phytate$ was delayed approximately $2{\sim}3$ days later than that of $^{99m}Tc-DISIDA$. In acute radiation induced injury, the results demonstrated that the recovery of Kupffer cells was delayed more than that of hepatocytes. This discrepancy was considered due to the differences in repair activities between these cell types. The decreased of regional excretory value in irradiated area was found to be dose-dependent but had no corelation with regional uptakes of DISIDA and phytate. The decreased of regional excretory value observed in non-irradiated region suggested that irradiated liver might induce an indirect effect.

• Applied Chemistry
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• v.15 no.1
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• pp.17-20
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• 2011

A disposable light exposure detector kit has been developed by UV curing of a hydrogel material. The devised light exposure detector kit consisted of light sensitive structures, bottom plate, character sheet and sticky back plate. A light exposure detector kit has a serial light sensitive structures that contain various light sensitive dyes such as rhodamine and fluorescein. The light sensitive structure composed of UV curable hydrogel polymer material as a supporing material and photosensitive dye in a certain concentration. The fabrication procedure of the ligh exposure detector kit is very simple and fast due to UV curing procedure of a photopolymerizable hydrogel material such as poly(ethylene glycol) methyl ether acrylate (PEGMEA) and poly(ethylene glycol) diacrylate (PEGDA) with a photosensitive dye. By the proposed fabrication method, various size and shape of a light exposure detector kit could be fabricated using a flexible elastomer mold. Due to a fast and inexpensive fabrication method, the light exposure detector kit could be use a single use for various industrial applications. According to light irradation, the light sensitive structure on a light exposure detector kit could be lose its color by decomposition of a photosensitive dye chemical in the structure. Thus the amount of the exposed light on a substrate could easily be recognised by changing color or transparency of the structure.

• Applied Biological Chemistry
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• v.25 no.2
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• pp.105-109
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• 1982

The effect the physiochemical properties of red and white ginseng powder after $^{60}Co-{\gamma}$ ray irra diationduring the storage for 4 months at $25^{\circ}C$ was investigated. The storage periods and the treatment of irradation at various doses on ginseng powders has no significant effect on the proximate composition and color density of ginseng extract with 50% ethanol. No changes in the contents of saponin and its HPLC patterns were found during the storage. However, a little increase was found in the yield of 50% ethanol extract and Hunter's color value of powder. But generally it was found to be stable in the physicochemical properties of red and white ginseng powder by irradiation of the intensity during the storage.

• Korean Chemical Engineering Research
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• v.51 no.1
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• pp.116-120
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• 2013

Characteristics of photocatalytic CO removal process conducting CO conversion by using Pt loaded $TiO_2$ photocatalyst were investigated in a photocatalytic tubular reactor. Effects of Pt loading method onto $TiO_2$, linear velocity of gas stream containing CO gas, CO concentration and moisture content in the gas stream on the conversion of CO to $CO_2$ were examined. It was found that the CO gas could be removed almost 100% by using photocatalytic tubular reactor internally coated with Pt/$TiO_2$ photocatalyst under UV irradiation, when the linear velocity of gas stream was in the range of 0.01~0.25 m/s and CO concentration in the gas stream was ranged from 20 to 100 ppm and the relative humidity of the gas stream was in the range of 20~40%. The conversion of CO gas decreased gradually with increasing linear velocity of gas stream and CO concentration in the gas stream. The moisture in the gas stream could promote the removal of CO gas by means of the generation of OHradicals.

• Korean Journal of Environmental Biology
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• v.17 no.3
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• pp.263-270
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• 1999

In order to identify the morphological changes of tissues in mouse after irradiation. We have observed the redistribution of LDH isozymes and the morphological changes of skeletal muscle, heart, kidney, liver and testis in mouse according to variation amount with the time after the 1 Gray and 3 Gray irradiation each. As a result of H-E (hematoxylin-eosin) stain, the apoptotic bodies were more easily observed in the liver than the other tissues and the quantity of the apoptotic bodies was proportionated to radiation amount. The number of apoptotic bodies was shown the highest at 1 day in most tissues and at 7 day in testis after irradiation. TUNEL (terminal deoxyribonucleodtidyl transferase-mediated dUTP-digoxigenin nick end labeling) staining was shown the same results as H-E staining. After the irradiation, the protein content was reduced in tissues except kidney. And protein content was reduced in all tissues at the initial period of 2 hours after 3 Gy irradiation. But it increased at 7 days after irradiation. LDH (EC 1.1.1.27, lactate dehydrogenase) activity was increased mostly in tissues at the early stage after 1 Gy irradiation. The maximum activity was detected earlier stage after 1 Gy irradiation than 3 Gy irradiation. The activity of LDH $A_4$ isozyme was decreased in the skeletal muscle, heart, kidney, and testis. The activity of $B_4$ and $A_2$$B_2$ sozyme was increased in the skeletal muscle and heart, and the activity of heterotetramer isozyme was increased in kidney The activity of $A_4$ isozyme in liver was detected high level and the activity of isozyme including subunit C elevated in testis. Therefore, LDH isozyme seems to play a role of lactate oxidase in most tissues except liver after irradiation. These data support that LDH isozyme is predomintly involved in the aerobic metabolism.

• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.628-632
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• 2013

Arthrospira platensis (A. platensis) is an economically important microalgae because it has carbohydrates, lipids, proteins and a number of phytochemicals. It is also a valuable source used in the production of biodiesel and functional foods. In this study, A. platensis was exposed to electron beam irradation (240 kGy) and induced random mutagenesis for strain improvement. Several mutants were obtained, and the resulting mutant was designated as EB29. The growth rate and chlorophyll content of EB29 was similar to those of wild type. However, the lipid content of EB29 was increased seven-fold compared to that of wild type when comparing the nile red fluorescent intensity. Semi-quantitative analysis of EB29 using the calibration plot of standard lipid, triolein, represented $78.6{\mu}g/mL$, which increased 2 times compared to wild type ($41.4{\mu}g/mL$). When analyzing the fatty acid profile of EB29, polyunsaturated fatty acids (PUFAs), such as gamma-linolenic acid (GLA) in EB29 increased about six-fold. Moreover, fatty acids affecting the quality of biodiesel increased compared to that of wild type. Thus, electron beam could be used for the strain improvement of microalgae in order to accumulate PUFAs and alteration of fatty acid profile for biodiesel.