• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.66-70
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• 1995

The soil humic acid was subdivided into four subfractions by molecular weight (F1: >100.000 dalton; F2: >100.000 dalton; F3: >10.000 dalton; F4: >2.000 dalton) using MP-dual hollow fiber ultrafiltration system. The characterization using IR, 1H and 13C NMR spectroscopy, showed similar spectroscopic features of HA, demonstrating that the bulk properties of HA subfractions are very similar to one another. IR spectral data showed a decrease in polysaccharide contents and increase in carboxylate functionality as molecular weight become smaller.functions. The structure of (NO) can be described by two interactions (N${\cdot}{\cdot}{\cdot}$N, N${\cdot}{\cdot}{\cdot}$O). One is the ONNO structure with an (N${\cdot}{\cdot}{\cdot}$N) interaction. In this structure, acyclic cis-ONNO with $C_{2v}$-symmetry, acyclic trans-ONNO with $C_{2h}$, and cyclic ONNO with trapezoidal structure ($C_{2v}$) are optimized at the MP2 level. The other structure is the ONON structure with an (N${\cdot}{\cdot}{\cdot}$O) interaction. In the structure, acyclic cis-ONON with Cs$^{-symmetry}$ and cyclic ONON of the rectangular ($C_{2h}$), square $(D_{2h})$, rhombic $(D_{2h})$, and parallelogramic $(D_{2h})$ geometries are also optimized. It is found that acyclic cis-ONNO $(^1A_1$) is the most stable structure and cyclic ONNO ($^3A_1$) is the least stable. Acyclic trans-ONNO ($^3A_1$) with an (N${\cdot}{\cdot}{\cdot}$N) interaction, acyclic trans-ONON and bicyclic ONON $(C_{2v})$ with (N${\cdot}{\cdot}{\cdot}$O) interaction, and acyclic cis- and trans-NOON with an (O${\cdot}{\cdot}{\cdot}$O) interaction can not be optimized at the MP2 level. Particularly, acyclic trans-ONNO with $C_{2h}$-symmetry can not be optimized at the CCSD(T) level. Meanwhile, acyclic NNOO ($^1A_1$, $C_s)$ and trianglic NNOO ($^1A_1$,$C_{2v})$ formed by the (O${\cdot}{\cdot}{\cdot}$N) interaction between $O_2$and $N_2$are optimized at the MP2 level. The binding energies and the relative energy gaps among the isomers are found to be relatively small./sec. Spiral CT scans during the arterial phase were obtained 35 seconds after the injection of contrast medium. CT findings of 78 lesions less than 4cm in diameter were correlated with angiographic findings. Results : The attenuation of lesions was high(n = 69), iso(n = 5), and low(n = 4) compared with liver parenchyma during the arterial phase of spiral CT. In lesions with high-, iso-, and low-attenuation during the arterial phase of spiral CT, hypervascularity on angiograms was found in 63 of 69(91.3%), three of five(60%), and three of four lesions(75%), respectively. Six lesions with high-attenuation on the arterial phase of spiral CT were not seen on angiography. Two iso-attenuated and one low-attenuated lesion were hypovascular on angiograms. Conclusion : The results of this study suggest that with some exceptions there was good correlation between the arterial phase of spiral CT and angiography.

• Food Science and Preservation
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• v.24 no.5
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• pp.565-575
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• 2017

This study was carried out to investigate shelf-life and quality of fresh-cut Dungkunma (Dioscorea bulbifera) in order to elevate utilization of Dungkunma a fresh food. Before vacuum-packaging (in polyethylene/polypropylene film ($100{\mu}m$, $15{\times}20cm$, $75{\pm}2cmHg$) and storaging at $2^{\circ}C$, Dungkunma was peeled out and cut to dice type ($2.0{\pm}0.5cm^3$), and then washed and blanched using hot water (at $90{\pm}2^{\circ}C$ with 2% NaCl solution for 30 sec). Blanched Dungkunma was pre-dried at room temperature, $40^{\circ}C$ and $50^{\circ}C$ for removing surface water. Each peeled dice Dungkunma was packed 50 g in polyethylene/polypropylene film ($100{\mu}m$, $15{\times}20cm$) with vacuum treatment ($75{\pm}2cmHg$) and stored at $2^{\circ}C$ for 90 days. Hardness and adhesiveness of Dungkunma blanched by 2% NaCl and pre-dried at $50^{\circ}C$ (SB50) were the highest, but changes were the least during storage. Lightness and yellowness of stored Dungkunma in all treatments decreased slightly while redness increased during storage. Changes of color of SB50 was the least. Total concentration of aerobic bacteria in SB50 was $1.88{\pm}0.18log\;CFU/g$ during 90 days and E. coli was detected in all treatments during whole storage periods. Dioscin and allantoin contents of SB50 were virtually unchanged during the storage. Consequently, the results of this study suggest that vacuum packaged Dungkunma after blanching using 2% NaCl solution could be effective to prolong the quality of fresh-cut Dungkunma.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.427-430
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• 2001

We prepared 10cm-diameter Si(100)/500 $\AA$-Si$_3$N$_4$/Si(100) wafer Pairs adopting 500 $\AA$ -thick Si$_3$N$_4$layer as insulating layer between single crystal Si wafers. Si3N, is superior to conventional SiO$_2$ in insulating. We premated a p-type(100) Si wafer and 500 $\AA$ -thick LPCVD Si$_3$N$_4$∥Si (100) wafer in a class 100 clean room. The cremated wafers are separated in two groups. One group is treated to have hydrophobic surface and the other to have hydrophilic. We employed a FLA(fast linear annealing) bonder to enhance the bond strength of cremated wafers at the scan velocity of 0.1mm/sec with varying the heat input at the range of 400~1125W. We measured bonded area using a infrared camera and bonding strength by the razor blade crack opening method. We used high resolution transmission electron microscopy(HRTEM) to probe cross sectional view of bonded wafers. The bonded area of two groups was about 75%. The bonding strength of samples which have hydrophobic surface increased with heat input up to 1577mJ/$m^2$ However, bonding strength of samples which have hydrophilic surface was above 2000mJ/$m^2$regardless of heat input. The HRTEM results showed that the hydrophilic samples have about 25 $\AA$ -thick SiO layer between Si and Si$_3$N$_4$/Si and that maybe lead to increase of bonding strength.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.242-251
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• 1989

The salted-dried mullet(Mugil japonicus) roe is a kind of traditional food particulary in the area of Young-am gun, Chunnam province. This study was conducted to conform the scientific processing conditions and to evaluate the nutritional quality and changes of major components during storage times. The manufacturing method was that the fresh roe was salted for about 20 hours for the preparation of salted-dried roe, washed by clean waters, drained, shaped a flat piece with 1.2cm thickness by pressing, and spreaded sesame oils on the surface of the salted roe periodically during wind drying for 20 days. The dried roe was blanched in heated water$(80^{\circ}C/3min)$ and packaged the dried product for storages. The fractional compositions of free lipid of wind dried roe were 40% of neutral lipids, 12% of glycolipids and 9% of phospholipids and those of bound lipids were 13% of neutral lipids. 10% of glycolipids and 13% of phospholipids respectively. The major fatty acids of the roe were $C_{16:0}$, $C_{18:0}$, $C_{18:1}$, $C_{18:2}$ and $C_{20:0}$ which was consisted of free and bound lipids in wind drying method during processing and storages. Total amino acids were 99.87g/100g and major amino acids were Glu, Pro, Leu, Lys and CySH and the protein score was average 155% and the chemical score was average 109%. Free amino acids was 1,376mg% that had 50.61% of Pro and the major kinds of those were Tyr and CySH.

• Sleep Medicine and Psychophysiology
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• v.6 no.1
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• pp.52-60
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• 1999

Objectives: With the object of finding the appropriate conditions and algorithms for dimensional analysis of human EEG, we calculated correlation dimensions in the various condition of sampling rate and data aquisition time and improved the computation algorithm by taking advantage of bit operation instead of log operation. Methods: EEG signals from 13 scalp lead of a man were digitized with A-D converter under the condition of 12 bit resolution and 1000 Hertz of sampling rate during 32 seconds. From the original data, we made 15 time series data which have different sampling rate of 62.5, 125, 250, 500, 1000 hertz and data acqusition time of 10, 20, 30 second, respectively. New algorithm to shorten the calculation time using bit operation and the Least Trimmed Squares(LTS) estimator to get the optimal slope was applied to these data. Results: The values of the correlation dimension showed the increasing pattern as the data acquisition time becomes longer. The data with sampling rate of 62.5 Hz showed the highest value of correlation dimension regardless of sampling time but the correlation dimension at other sampling rates revealed similar values. The computation with bit operation instead of log operation had a statistically significant effect of shortening of calculation time and LTS method estimated more stably the slope of correlation dimension than the Least Squares estimator. Conclusion: The bit operation and LTS methods were successfully utilized to time-saving and efficient calculation of correlation dimension. In addition, time series of 20-sec length with sampling rate of 125 Hz was adequate to estimate the dimensional complexity of human EEG.

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.387-397
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• 2000

Background : Intravascular Laser Irrardiation of Blood(ILIB) is used in disorder of cerebral and peripheral blood circulation, dysfunction of brain, atherosclerosis etc., but there are little study about ILIB in oriental medicine. We wished to assess the efficacy of ILIB for the treatment of cerebral infarction. Method : The study group comprised 40 patients who arrived at hospital during 48 hours after attack. All patient were divided into two group. The control group was treated with Uhuangcheongsimhuan(牛黃淸心丸), Seonghyangjeonggisan(星香正氣散), acupuncture therapy only, while the ILIB group was treated with above therapy plus 5 days of irradiation of He-Ne Laser(1.8~2.5mW, 50min. per day). In rat model of middle cerebral artery(MCA) occlusion, the control group was not treated, while the ILIB group was treated with irradiation of He-Ne Laser(1.8~2.5mW, 24sec.). Result : 1. Symptom improve scores did not showed significant difference between control and ILIB group. 2. Vasoreactivity of carotid siphon did not showed significant difference between control and ILIB group. 3. Vasoreactivity of radial artery did not showed significant difference between control and ILIB group. 4. PT a-PTT did not showed significant changes between before and after treatment in both group. Fibrinogen significantly increased after treatment in ILIB group(p<0.05)), but it was in normal degree. 5. ILIB showed a significant decrease of brain ischemic area and edema in rat model of middle cerebral artery(MCA) occlusion. Conclusion : These findings suggest that additional treatment of ILIB is not more useful than traditional therapy only in acute cerebral infarction. But ILIB showed potential effect in rat model of MCA occlusion. So further investigation will be necessary.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.4
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• pp.324-332
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• 2011

Purpose: The purpose of this study was to compare the stress distribution of teeth and jaw on load by differentiating property of materials according to each layer of widely used mouthguard. Materials and methods: A Korean adult having normal cranium and mandible was selected to examine. A customized mouthguard was constructed by use of DRUFOMAT plate and DRUFOMAT-TE/-SQ of Dreve Co. according to Signature Mouthguard system. The cranium was scanned by means of computed tomography with 1mm interval. It was modeled with CANTIBio BIONIX/Body Builder program and simulated and interpreted using Alter HyperMesh program. The mouthguard was classified as follows according to the layers. (1) soft guard (Bioplast)(SG) (2) hard guard (Duran)(HG) (3) medium guard (Drufomat)(MG) (4) soft layer + hard layer (SG + HG) (5) hard layer + soft layer (HG + SG) (6) soft layer + hard layer + soft layer (SG + HG + SG) (7) hard layer + soft layer + hard layer (HG + SG + HG) The impact locations on mandible were gnathion, the center of inferior border, and the anterior edge of gonial angle. And the impact directions were oblique ($45^{\circ}$). The impact load was 800 N for 0.1 sec. The stress distribution was measured at maxillary teeth, TMJ and maxilla. The statistics were conducted using Repeated ANOVA and in case of difference, Duncan test was used as post analysis. Results: In teeth and maxilla, the mouthguard contacting soft layer of mandibular teeth presented lowest stress measure and, in contrast, in condyle, the mouthguard contacting hard layer of mandibular teeth presented lowest stress measure. Conclusion: For all impact directions, soft layer + hard layer + soft layer, the mouthguard with three layers which the hard layer is sandwiched between two soft layers, showed relatively even distribution of stress in impact.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.528-537
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• 2008

60 nm and 20 nm thick hydrogenated amorphous silicon(a-Si:H) layers were deposited on 200 nm $SiO_2$/single-Si substrates by inductively coupled plasma chemical vapor deposition(ICP-CVD). Subsequently, 30 nm-Ni layers were deposited by an e-beam evaporator. Finally, 30 nm-Ni/(60 nm and 20 nm) a-Si:H/200 nm-$SiO_2$/single-Si structures were prepared. The prepared samples were annealed by rapid thermal annealing(RTA) from $200^{\circ}C$ to $500^{\circ}C$ in $50^{\circ}C$ increments for 40 sec. A four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), and scanning probe microscopy(SPM) were used to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure, and surface roughness, respectively. The nickel silicide from the 60 nm a-Si:H substrate showed low sheet resistance from $400^{\circ}C$ which is compatible for low temperature processing. The nickel silicide from 20 nm a-Si:H substrate showed low resistance from $300^{\circ}C$. Through HRXRD analysis, the phase transformation occurred with silicidation temperature without a-Si:H layer thickness dependence. With the result of FE-SEM and TEM, the nickel silicides from 60 nm a-Si:H substrate showed the microstructure of 60 nm-thick silicide layers with the residual silicon regime, while the ones from 20 nm a-Si:H formed 20 nm-thick uniform silicide layers. In case of SPM, the RMS value of nickel silicide layers increased as the silicidation temperature increased. Especially, the nickel silicide from 20 nm a-Si:H substrate showed the lowest RMS value of 0.75 at $300^{\circ}C$.

• Journal of Life Science
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• v.22 no.10
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• pp.1407-1414
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• 2012

Hormone replacement therapy (HRT) is an effective regimen that has been found to prevent these diseases in postmenopausal women. However, HRT is accompanied by an increased risk of unfavorable outcomes. This study was conducted to evaluate the effects of Eisenia Bicyclis extract on lipids in ovariectomized rats. Fifty 7-week-old female Sprague-Dawley rats were randomly assigned to four groups: sham-operated rats (SHAM), ovariectomized rats (OVX-CON), and ovariectomized rats that were treated with Eisenia bicyclis extracts. The extract-treated diets were fed to the rats for 6 weeks after operation. Antioxidant effects were measured by DPPH free radical scavenging activity. Antioxidant activity of the ethanol extract increased in a dose-dependent manner and was about 55.9% in a concentration of 100 ${\mu}g/ml$. We measured the total cholesterol content, triglyceride content, HDL-cholesterol content, LDL-cholesterol content, atherosclerotic index, cardiac risk factor in serum, and anti-platelet aggregation and blood rheology. The total cholesterol and triglyceride concentration in serum increased for the OVX-control group, but supplementation with the E. bicyclis extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the OVX-EB200 group was significantly lower than the OVX-CON group. In addition, the blood passage times in rats that received the E. bicyclis extract were more rapid than the times in the untreated group (OVX-CON). Microscopic evaluation revealed that whole blood passed more smoothly through the microchannels in rats in the E. bicyclis extract supplement groups. Our results clarified the effects of E. bicyclis extract on serum lipid content in ovariectomized rats, and consequently we expect positive effects from providing E. bicyclis extract to postmenopausal women with cardiovascular disease.

• Journal of Life Science
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• v.23 no.12
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• pp.1501-1508
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• 2013

This study investigated antioxidant activity and the lipid content of serum for the possible outcome of improving the activity of Ishige okamurae extracts in ovariectomized rats. The antioxidant effects of an Ishige okamurae water extract and an Ishige okamurae ethanol extract were measured by evaluating DPPH free radical scavenging activity and SOD-like activity. Fifty, seven-week old female Sprague Dawley rats were randomly assigned to five groups as follows: sham-operated rats (SHAM), ovariectomized rats (OVX-CON), ovariectomized rats that were treated with 17-beta-estradiol (200 ${\mu}g/kg/day$), and ovariectomized rats that were treated with Ishige okamurae extracts (50 mg/kg/day and 200 mg/kg/day, respectively). The diets were fed to the rats for seven weeks after ovariectomy. The antioxidant activities of the water and ethanol extracts of Ishige okamurae increased in a dose-dependent manner, and the ethanol extract was found to be higher than the water extract. Therefore, we examined the effect of an Ishige okamurae ethanol extract on total serum cholesterol, triglycerides, HDL-cholesterol, and LDL-cholesterol levels, and anti-platelet aggregation. The total-cholesterol and triglyceride content of the serum increased in the OVX-CON group compared to the SHAM group, but supplementation with the Ishige okamurae ethanol extract caused these factors to decrease. Notably, the serum LDL-cholesterol concentration in the supplemented 200 mg/kg/day Ishige okamurae ethanol extract group was significantly more reduced than it was in the OVX-CON group. In addition, the platelet aggregation ability was lower in the groups treated with Ishige okamurae than it was in the OVX-CON group. According to these results, the effects of Ishige okamurae extract on serum lipid content in ovariectomized rats were illuminated.