• Journal of Ginseng Research
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• v.39 no.3
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• pp.221-229
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• 2015

Background: Minor ginsenosides, those having low content in ginseng, have higher pharmacological activities. To obtain minor ginsenosides, the biotransformation of American ginseng protopanaxadiol (PPD)-ginsenoside was studied using special ginsenosidase type-I from Aspergillus niger g.848. Methods: DEAE (diethylaminoethyl)-cellulose and polyacrylamide gel electrophoresis were used in enzyme purification, thin-layer chromatography and high performance liquid chromatography (HPLC) were used in enzyme hydrolysis and kinetics; crude enzyme was used in minor ginsenoside preparation from PPD-ginsenoside; the products were separated with silica-gel-column, and recognized by HPLC and NMR (Nuclear Magnetic Resonance). Results: The enzyme molecular weight was 75 kDa; the enzyme firstly hydrolyzed the C-20 position 20-O-${\beta}$-D-Glc of ginsenoside Rb1, then the C-3 position 3-O-${\beta}$-D-Glc with the pathway $Rb1{\rightarrow}Rd{\rightarrow}F2{\rightarrow}C-K$. However, the enzyme firstly hydrolyzed C-3 position 3-O-${\beta}$-D-Glc of ginsenoside Rb2 and Rc, finally hydrolyzed 20-O-L-Ara with the pathway $Rb2{\rightarrow}C-O{\rightarrow}C-Y{\rightarrow}C-K$, and $Rc{\rightarrow}C-Mc1{\rightarrow}C-Mc{\rightarrow}C-K$. According to enzyme kinetics, $K_m$ and $V_{max}$ of Michaelis-Menten equation, the enzyme reaction velocities on ginsenosides were Rb1 > Rb2 > Rc > Rd. However, the pure enzyme yield was only 3.1%, so crude enzyme was used for minor ginsenoside preparation. When the crude enzyme was reacted in 3% American ginseng PPD-ginsenoside (containing Rb1, Rb2, Rc, and Rd) at $45^{\circ}C$ and pH 5.0 for 18 h, the main products were minor ginsenosides C-Mc, C-Y, F2, and C-K; average molar yields were 43.7% for C-Mc from Rc, 42.4% for C-Y from Rb2, and 69.5% for F2 and C-K from Rb1 and Rd. Conclusion: Four monomer minor ginsenosides were successfully produced (at low-cost) from the PPD-ginsenosides using crude enzyme.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.5
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• pp.704-723
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• 2000

This study was undertaken to evaluate the tensile bond strength of In-Ceram alumina core treat-ed by ion assisted reaction(IAR). Ion assisted reaction is a prospective surface modification technique without damage by a keV low energy ion beam irradiation in reactive gas environments or reactive ion itself. 120 In-Ceram specimens were fabricated according to manufacturer's directions and divided into six groups by surface treatment methods of In-Ceram alumina core. SD group(control group): sandblasting SL group: sandblasting + silane treatment SC group: sandblasting + Siloc treatment IAR I group: sandblasting + Ion assisted reaction with argon ion and oxygen gas IAR II group: sandblasting + Ion assisted reaction with oxygen ion and oxygen gas IAR III group: sandblasting + Ion assisted reaction with oxygen ion only For measuring of tensile bond strength, pairs of specimens within a group were bonded with Panavia 21 resin cement using special device secured that the film thickness was $80{\mu}m$. The results of tensile strength were statistically analyzed with the SPSS release version 8.0 programs. Physical change like surface roughness of In-Ceram alumina core treated by ion assistad reaction was evaluated by Contact Angle Measurement, Scanning Electron Microscopy, Atomic Force Microscopy; chemical surface change was evaluated by X-ray Photoelectron Spectroscopy. The results as follows: 1. In tensile bond strength, there were no statistically significant differences with SC group, IAR groups and SL group except control group(P<0.05). 2. Contact angle measurement showed that wettability of In-Ceram alumina core was enhanced after IAR treatment. 3. SEM and AFM showed that surface roughness of In-Ceram alumina core was not changed after IAR treatment. 4. XPS showed that IAR treatment of In-Ceram alumina core was enabled to create a new functional layer. A keV IAR treatment of In-Ceram alumina core could enhanced tensile bond strength with resin cement. In the future, this ion assisted reaction may be used effectively in various dental materials as well as in In-Ceram to promote the bond strength to natural tooth structure.

• The Korean Journal of Petroleum Geology
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• v.11 no.1 s.12
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• pp.9-17
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• 2005

In the main target area of the block II, Targe-scale faults occur below the unconformity developed around 1 km in depth. The contrast of seismic velocity around the unconformity is generally so large that the strong multiples and the radical velocity variation would deteriorate the quality of migrated section due to serious distortion. More than 15 kinds of data processing techniques have been applied to improve the image resolution for the structures farmed from this active crustal activity. The bad and noisy traces were edited on the common shot gathers in the first step to get rid of acquisition problems which could take place from unfavorable conditions such as climatic change during data acquisition. Correction of amplitude attenuation caused from spherical divergence and inelastic attenuation has been also applied. Mild F/K filter was used to attenuate coherent noise such as guided waves and side scatters. Predictive deconvolution has been applied before stacking to remove peg-leg multiples and water reverberations. The velocity analysis process was conducted at every 2 km interval to analyze migration velocity, and it was iterated to get the high fidelity image. The strum noise caused from streamer was completely removed by applying predictive deconvolution in time space and ${\tau}-P$ domain. Residual multiples caused from thin layer or water bottom were eliminated through parabolic radon transform demultiple process. The migration using curved ray Kirchhoff-style algorithm has been applied to stack data. The velocity obtained after several iteration approach for MVA (migration velocity analysis) was used instead or DMO for the migration velocity. Using various testing methods, optimum seismic processing parameter can be obtained for structural and stratigraphic interpretation in the Block II, Yellow Sea Basin.

• Journal of Nutrition and Health
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• v.35 no.1
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• pp.60-68
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• 2002

Purpose of this study was to compare serum phospholipid fatty acid composition of obese children with that of normal weight children reside in Kangnung area. Subjects were consisted of 56(41 boys and 15 girls) moderately or severely obese elementary school children, and age and sex-matched normal weight children as a control group. Level of serum phospholipid fatty acids was measured by thin layer chromatography(TLC) followed by gas chromatography(GLC). for male subjects, serum triglyceride(121 $\pm$ 4.7mg/dl) and total cholesterol(180 $\pm$ 37.1mg/dl) concentrations were significantly(p < 0.05) higher in obese group than those for control group(81.5 $\pm$ 2.5mg/dl and 161 $\pm$ 32.0mg/dl, respectively). Obese group showed significantly higher percentage of serum phospholipid myristic acid(C14:0) than the value for control group in both male and female subjects. Obese male subjects had significantly higher percentages of palmitoleic acid(16 : 1), oleic acid(18 : 1), dihomo-${\gamma}$-linoleic acid(20 : 3, $\omega$6) and docosatetraenoic acid(22 : 4, $\omega$6), and lower percentages of eicosenoic acid(20 : 1, $\omega$6), docosapentaenoic acid(22 : 5, $\omega$6), EPA(22 : 5, $\omega$3) and DHA (22 : 6, $\omega$3) compared to values for control male subjects. For male subjects, obese group showed significantly higher ratios of 16 : 1($\omega$9)/16 : 0 and 18 : 1($\omega$9)/18 : 0, and significantly lower ratios of 22 : 5($\omega$6)/22 4($\omega$6), and 22 : 6($\omega$3)/22 : 5($\omega$3) compacted to values for the control group. But there was not significant differences in elongation and desaturation indices of serum phospholipids fatty acid metabolism between obese and control group in female subjects. Most of anthropometric measurements related to obesity were negatively correlated with the percentages of PUFA, $\omega$3 fatty acids or DHA(22 : 6, $\omega$3), and positively correlated with the percentage of myristic acid(14 : 0) or $\omega$6/$\omega$3 ratio in serum phospholipids. Serum triglyceride concentration was negatively correlated with the percentage of PUFA or $\omega$3 fatty acids, and positively correlated with $\omega$6/$\omega$3 ratio in serum phospholipids. These results indicate that obesity related changes in blood lipid levels and metabolism are more significant in male subjects than in female subjects. Also changes in serum phospholipid fatty acid composition observed in obese children appear to demonstrate the increased susceptibility of these children to cardiovascular disease and other related chronic diseases.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.77-83
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• 1971

In order to find out the decomposing factors of Sumithion in mineral diluents, the physical and chemical properties of the diluents such as talcs, bentonites, diatomaceous earth and other clay minerals was studied in relation to the decomposition rate of Sumithion in dust formulations. The total base, moisture adsorption capacity, pH, specific surface, water contents, active $Fe^{++}$, ignition loss and cation exchange capacity were analysed as the properties of mineral diluents, and these properties were correlated with the stability of Sumithion in dust formulations. And in hope of finding out the main factors among those properties of diluents, the decomposed products of Sumithion in dust formulations prepared with standard Sumithion were separated by the methods of column chromatography and investigated by thin layer chromatography. The following results were otbained; 1. The total base, moisture adsorption capacity, specific surface, water contents, active $Fe^{++}$ and cation exchange capacity of mineral diluents were found to be highly effective on the rate of decomposition of Sumithion in dust formulations. 2. Decomposed products of Sumithion in dust formulations were found to be dimethylphosphorothionate, 3-methyl-4-nitro phenol and its derivatives. And one fraction was not dissolved in n-hexane and ethylether, but was soluble in methylalcohol and ethylalcohol. 3. The moat highly correlated properties of diluents with the decomposition rate of Sumithion in dust were found to be the total base and water contents. 4. In regard to the kind of diluents, it was found that the rate of decomposition of Sumithion in dust formulations was higher in order of bentonite, diatomaceous earth, kaolin and talc.

• Journal of the Korean Vacuum Society
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• v.7 no.4
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• pp.368-373
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• 1998

As device dimensions approach submicrometer size in ULSI, the demand for interlayer dielectric materials with very low dielectric constant is increased to solve problems of RC delay caused by increase in parasitic resistance and capacitance in multilevel interconnectins. Fluorinated amorphous carbon in one of the promising materials in ULSI for the interlayer dielectric films with low dielectric constant. However, poor thermal stability and adhesion with Si substrates have inhibited its use. Recently, amorphous hydrogenated carbon (a-C:H) film as a buffer layer between the Si substrate and a-C:F has been introduced because it improves the adhesion with Si substrate. In this study, therfore, a-C:F/a-C:H films were deposited on p-type Si(100) by ECRCVD from $C_2F_6, CH_4$and $H_2$gas source and investigated the effect of forward power and composition on the thickness, chemical bonding state, dielectric constant, surface morphology and roughness of a-C:F films as an interlayer dielectric for ULSI. SEM, FT-IR, XPS, C-V meter and AFM were used for determination of each properties. The dielectric constant in the a-C:F/a-C:H films were found to decrease with increasing fluorine content. However, the dielectric constant increased after furnace annealing in $N_2$atomosphere at $400^{\circ}C$ for 1hour due to decreasing of flurorine content. However, the dielectric constant increased after furnace annealing in $N_2$atmosphere at $400^{\circ}C$ for 1hour due to decreasing of fluorine concentration.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.9-18
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• 1996

Streptococcus mutans has been implicated as primary causative agents of dental caries by insoluble glucan (IG) in human and experimental animals. An attempt was made to search for the ${\alpha}$-1,3 glucanase that degrades IG produced by S. mutans. ${\alpha}$-1,3 glucanase was detected in the culture supernatant of microorganisms, which are isolated from soils on agar medium containing IG as a sole carbon source. This Streptomyces sp. hydrolysed IG produced by immobilized S. mutans and was named as Y9373. This enzyme required ${\alpha}$-1,3 glucan (IG) as an inducer. The optimum conditions for enzyme production were studied. The enzyme was purified by 30~70% $(NH_4)_2SO_4$ precipitation, anion exchange chroma tography on DEAE-cellulose and gel filtration on Sepadex G-75. The purified enzyme has a specific activity of 7840.0 U/mg protein giving 32.1-fold purification and final yield of 0.53%. The molecular weight was estimated to be about 22.5 kDa by SDS-PAGE. The optimum pH and temperature for enzyme reaction were 6.5 and 37$^{\circ}C$, respectively and the enzyme was relatively stable at the temperature below 60$^{\circ}C$. The activity of purified enzyme was enhanced by adding $Co^{2+},\;Mn^{2+}\;and\;Mg^{2+}$ into the medium, whereas inhibited by adding $Hg^{2+},\;Zn^{2+}$ and SDS. The $K_m\;and\;V_{max}$ value of ${\alpha}$-1,3 glucanase for IG were estimated to be 2.50 mM and 0.0431 mM/min, respectively. The thin layer chromatographic analysis of hydrolysates from IG with ${\alpha}$-1,3 glucanase showed that glucose was the main product of reaction. This enzyme activity was about 14 times higher than marketing dextranase as preventive agent against artificial dental caries by S. mutans in TH medium including 5% sucrose after 30 minutes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.293-299
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• 1987

At various times and places all over the world men have become ill and some have died after eating shellfish that were intoxicated with paralytic shellfish poison(PSP) caused by Protogonyaulax spp. In late March, 1986, two persons were dead by ingesting wild sea mussels, Mytilur edulis, grown at bottom of an anchored waste ship to be dismantled at Gamchun Bay, Pusan, Korea. The samples were collected from the bottom of the ship during April $1\~April$ 8 of the year to find the cause of the food poisoning accident. The toxicity was estimated by bioassay with ICR male mouse, while the toxins were extracted and characterized. The toxins were extracted with acidified $80\%$ ethanol. The extract was defatted three times with dichloromethane, treated with activated charcoal, and then purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxic fractions obtained were analysed by cellulose acetate membrane electrophoresis, thin layer chromatography and high performance liquid chromatogaphy. The range and the average of PSP-toxicity of the samples were $132\~295\;MU/g$, 203 MU/g respectively. The amount of PSP was $26.4\~58.9{\mu}g/g$ of whole meat in range and $40.6{\mu}g/g$ in average. The toxicity of the digestive gland of the samples was 9 times higher than that of edible meat (except digestive gland) as $439\~979MU/g$, and it was about $70\%$ in total toxin. The compositional analytical results of the paralytic shellfish toxin, Gonyautoxin $1\~4$ were the major part of the PSP and Saxitoxin and neosaxitoxin were detected as the minor component. It was concluded that the food poisoning accident was caused not by Saxitoxins but by Gonyautoxins.

• The Korean Journal of Mycology
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• v.43 no.4
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• pp.247-252
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• 2015

Aronia (Black chokeberry, Aronia melanocarpa) belonging to the Rosaceae family, is native to eastern North America. Aronia contain high levels of flavonoids, mostly anthocyanins and proanthocyanidins, which are known as condensed tannins. The dominant proanthocyanidins in aronia are (-)-epicatechin and (+)-catechin. The concentration of proanthocyanidins in aronia is higher than in other berries, however due to the astringent taste it is not desirable for consumption. Therefore, the purpose of this study is to evaluate the effect of aronia on the reduction in tannins by yeast isolated from regional Jeotgal. We isolated strains of yeast with high ${\beta}$-glucosidase activity from Jeotgal, with the MTY2 strains exhibiting a reduction in final tannin concentration according to thin layer chromatography (TLC) analysis. MTY2 was confirmed as Kazachstania servazzii using an 18S rDNA sequence and named as K. servazzii MTY2. K. servazzii MTY2 showed most significant growth when K. servazzii MTY2 was cultured in a solution of 10% (w/v) glucose, 3% (w/v) tryptone and 0.1% (w/v) sodium chloride. According to the high performance liquid chromatography (HPLC) analysis, the (+) - catechin peak is present, but (-) - epicatechin peak was reduced at culture condition added with 10% glucose in medium.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.187-203
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• 2000

The precipitation of calcium phosphate on implant surface has been known to accelerate osseointegration and to enhance osseous adaptation. The present study was performed to examine whether the precipitation of calcium phosphate on Ti-6Al-4V alloy could be affected by the immersion in NaOH solution and heat treatment. Ti-6Al-4V alloy plates of $15{\times}3.5{\times}1mm$ in dimension were polished sequentially from #240 to #2,000 emery paper and one surface of each specimen was additionally polished with $0.1{\mu}m$ alumina paste. Polished specimens were soaked in various concentrations of NaOH solution(0.1, 1.0, 3.0, 5.0, 7.0, 10.0 M) at $60^{\circ}C$ for 24 hours for alkali treatment, and 5.0 M NaOH treated specimens were heated for 1 hour at each temperature of 400, 500, 600, 700, $800^{\circ}C$. After the alkali and heat treatments, specimens were soaked in the Hank's solution with pH 7.4 at $36.5^{\circ}C$ for 30days.The surface ingredient change of Ti-6Al-4V alloy was evaluated by thin-film X-ray diffractometer(TF-XRD) and the surface microstructure was observed by scanning electron microscope(SEM), and the elements of surface were analyzed by X-ray photoelectron spectroscopy(XPS). The results were obtained as follows ; 1. The precipitation of calcium phosphate on Ti-6Al-4V alloy was accelerated by the immersion in NaOH solution and heat treatment. 2. In Alkali treatment for the precipitation of calcium phosphate on Ti-6Al-4V alloy, the optimal concentration of NaOH solution was 5.0 M. 3. In heat treatment after alkali treatment in 5.0 M NaOH solution, the crystal formation on alloy surface was enhanced by increasing temperature. In heat treated alloys at $600^{\circ}C$, latticed structure and prominences of calcium phosphate layer were most dense. On heat treated alloy surface at the higher temperature(${\geq}700^{\circ}C$), main crystal form was titanium oxide rather than apatite. The above results suggested that the precipitation of calcium phosphate on the surface of Ti-6Al-4V alloy could be induced by alkali treatment in 5.0 M-NaOH solution and by heat treatment at $600^{\circ}C$.