• Journal of Mushroom
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• v.10 no.2
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• pp.74-82
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• 2012

Sixty strains of Pleurotus ostreatus, white-rot fungi, were screened for production ability of their lignocellulolytic enzymes to selectively wood degradation. That results were shown that all of screened strains were produced lignocellulolytic enzymes on 2nd screening liquid culture medium. However, cellulase activity of selected six strains of P. ostreatus was low in avicel-yeast-peptone liquid culture medium. In the case of xylan degrading enzyme, No. 6 and No. 38 strains produced a xylanase(above 1.0U/ml) and a 1,4-${\beta}$-xylosidase (above 0.15 U/ml). Examination of the ligninolytic enzyme profiles of selected thirteen strains of the P. ostreatus, in the presence of Remazol Brilliant Blue R(RBBR), were observed that laccase(Lac) activity were earlier reached maximum level(0.8-2.0 U/ml) and then Mn-dependent peroxidase (MnP) were reached maximum level(0.5-1.5 U/ml) in glucose-yeast-peptone(GYP) medium. On the other hand, activity of lignin peroxidase(LiP) was not detected in this medium. I selected the No. 42 strain of P. ostreatus produced high levels of Mn-dependent peroxidase and laccase based on the screening method.

• Journal of the Korean Mathematical Society
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• v.53 no.4
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• pp.929-967
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• 2016

Let p(t, x) be the fundamental solution to the problem $${\partial}^{\alpha}_tu=-(-{\Delta})^{\beta}u,\;{\alpha}{\in}(0,2),\;{\beta}{\in}(0,{\infty})$$. If ${\alpha},{\beta}{\in}(0,1)$, then the kernel p(t, x) becomes the transition density of a Levy process delayed by an inverse subordinator. In this paper we provide the asymptotic behaviors and sharp upper bounds of p(t, x) and its space and time fractional derivatives $$D^n_x(-{\Delta}_x)^{\gamma}D^{\sigma}_tI^{\delta}_tp(t,x),\;{\forall}n{\in}{\mathbb{Z}}_+,\;{\gamma}{\in}[0,{\beta}],\;{\sigma},{\delta}{\in}[0,{\infty})$$, where $D^n_x$ x is a partial derivative of order n with respect to x, $(-{\Delta}_x)^{\gamma}$ is a fractional Laplace operator and $D^{\sigma}_t$ and $I^{\delta}_t$ are Riemann-Liouville fractional derivative and integral respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.2
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• pp.185-192
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• 2016

Ampicillin, a ${\beta}$-lactam antibiotic, dose-dependently protects neurons against ischemic brain injury. The present study was performed to investigate the neuroprotective mechanism of ampicillin in a mouse model of transient global forebrain ischemia. Male C57BL/6 mice were anesthetized with halothane and subjected to bilateral common carotid artery occlusion for 40 min. Before transient forebrain ischemia, ampicillin (200 mg/kg, intraperitoneally [i.p.]) or penicillin G (6,000 U/kg or 20,000 U/kg, i.p.) was administered daily for 5 days. The pretreatment with ampicillin but not with penicillin G significantly attenuated neuronal damage in the hippocampal CA1 subfield. Mechanistically, the increased activity of matrix metalloproteinases (MMPs) following forebrain ischemia was also attenuated by ampicillin treatment. In addition, the ampicillin treatment reversed increased immunoreactivities to glial fibrillary acidic protein and isolectin B4, markers of astrocytes and microglia, respectively. Furthermore, the ampicillin treatment significantly increased the level of glutamate transporter-1, and dihydrokainic acid (DHK, 10 mg/kg, i.p.), an inhibitor of glutamate transporter-1 (GLT-1), reversed the neuroprotective effect of ampicillin. Taken together, these data indicate that ampicillin provides neuroprotection against ischemia-reperfusion brain injury, possibly through inducing the GLT-1 protein and inhibiting the activity of MMP in the mouse hippocampus.

• The Korean Journal of Nuclear Medicine Technology
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• v.17 no.1
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• pp.62-66
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• 2013

Purpose: I-131 is a radioisotope widely used for thyroid gland treatments. The physical half life is 8.01 and characterized by emitting beta and gamma rays which is used in clinical practice for the purpose of acquiring treatment and images. In order to reduce the recurrence rate after surgery in high-risk thyroid cancer patients, the remaining thyroid tissue is either removed or the I-131 is used for treatment during relapse. In cases of using a high dosage of radioactive iodine requiring hospitalization, the patient is administered dosage in the hospital isolation ward over a certain period of time preventing I-131 exposure to others. By checking the radiation amount emitted from patients before discharge, the patients are discharged after checking whether they meet the legal standards (50 uSv/h). After patients are discharged from the hospital, the contamination level is checked in many parts of the ward before the next patients are hospitalized and when necessary, decontamination operations are performed. It is expected that there is exposure to radiation when measuring the ward contamination level and dose check emitted from patients at the time of discharge whereby the radiation exposure by health workers that come from the patients in this process is the main factor. This study analyzed the correlation between discharge dose of patients and ward contamination level through a variety of factors such as renal functions, gender, age, dosage, etc.). Materials and Method: The study was conducted on 151 patients who received high-dosage radioactive iodine treatment at Soon Chun Hyang University Hospital during the period between 8/1/2011~5/31/2012 (Male: Female: 31:120, $47.5{\pm}11.9$, average dosage of $138{\pm}22.4$ mCi). As various factors expected to influence the patient discharge dose & ward contamination such as the beds, floors, bathroom floors, and washbasins, the patient renal function (GFR), age, gender, dosage, and the correlation between the expected Tg & Tg-Tb expected to reflect the remaining tissue in patients were analyzed. Results: In terms of the discharge dose and GFR, a low correlation was shown in the patient discharge dose as the GFR was higher (p < 0.0001). When comparing the group with a dosage of over 150mCi and the group with a lower dosage, the lower dosage group showed a significantly lower discharge dose ($24{\pm}10.4uSv/h$ vs $28.7{\pm}11.8uSv/h$, p<0.05). Age, gender, Tg, Tg-Tb did not show a significant relationship with discharge dose (p> 0.05). The contamination level in each spot of the treatment ward showed no significant relationship with GFR, Tg, Tg-Tb, age, gender, and dosage (p>0.05 ). Conclusion: This study says that discharge of the dose in the patient's body is low in GFR higher and Dosage 150mCi under lower. There was no case of contamination of the treatment ward, depending on the dose and renal association. This suggests that patients' lifestyles or be affected by a variety of other factors.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.604-607
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• 1989

In this paper, the commutating devices of the forced commutating circuit and the relation between load current and source voltage are theoretically analyzed, by this approach commutating condition is considered. As a result some basic design methodes of commutating circuit are presented, whitch commutating loss becomes low and commutating failure is not occured.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.336-341
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• 1982

The histochemical examination of Undaria pinnatifida Laver were conducted with light microscope and electron microscope. The results obtained were as follow: 1. Undaria pinnatifida frond were composed with epidermis, cortex and medulla. But the cutting section of Undaria pinnatifida Laver showed that only the epidermal cell were bound to each other. The cortex and medulla of the frond were destroyed during U.P. Laver process. 2. To identification of bind material of U.P. Laver, which were treated with sodium carbonate solution for extraction of alginic acid and reacted with Periodic Acid Schiff(PAS) reagent. And the PAS reaction result was negative by light microscope observation. On this result, we found out that the alginic acid has the binder role of U.P. Laver. 3. Also, the bind structure of U.P. Laver were observed by electron microscope and could well find out the epidermal cell wall and bind position of alginic acid, which were could not observed by light microscope.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2410-2412
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• 2005

In this study, two types of PS substrate were fabricated for sensing of chemical and biological substances. For sensing of the humidity and chemical analyzes such as $CH_3OH$ or $C_2H_5OH$, PS layers are prepared by photoelectrochemical etching of silicon wafer in aqueous hydrofluoric acid solution. To evaluate their sensitivity, we measured the resistance variation of the PS diaphragm. As the amplitude of applied voltage increases from 2 to 6Vpp at constant frequency of 5kHz, the resistance variation for humidity sensor rises from 376.3 to $784.8{\Omega}$/%RH. And the sensitivities for $CH_3OH$ and $C_2H_5OH$ were 0.068 uA/% and 0.212 uA/%, respectively. For biological sensing application, amperometric urea sensors were fabricated based on porous silicon(PS), and planar silicon(PLS) electrode substrates by the electrochemical methods. Pt thin film was sputtered on these substrates which were previously formed by electrochemical anodization. Poly (3-methylthiophene) (P3MT) were used for electron transfer matrix between urease(Urs) and the electrode phase, and Urs also was by electrochemically immobilized. Effective working area of these electrodes was determined for the first time by using $Fe(CN)_6^{3-}/Fe(CN)_6^{4-}$ redox couple in which nearly reversible cyclic voltammograms were obtained. The $i_p$ vs $v^{1/2}$ plots show that effective working electrode area of the PS-based Pt thin film electrode was 1.6 times larger than the PLS-based one and we can readily expect the enlarged surface area of PS electrode would result in increased sensitivity by ca. 1.6 times. Actually, amperometric sensitivity of the Urs/P3MT/Pt/PS electrode was ca 0.91uA/$mM{\cdot}cm^2$, and that of the Urs/P3MT/Pt/PLS electrode was ca. 0.91uA/$mM{\cdot}cm^2$ in a linear range of 1mmol/L to 100mmol/L urea concentrations

• Applied Biological Chemistry
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• v.42 no.3
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• pp.252-255
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• 1999

Inhibition activities$(pI_{50})$ of chalcone derivatives as substrate with farnesyl protein transferase(FPTase) were determined in vitro. The structure activity relationships(SAR) between the activity and physicochemical parameters of X & Y-substituents on the phenyl groups were analyzed by Free-Wilson and Hansch method. X-substituents on the benzoyl group have the more important role to inhibition activity than Y-substituents on the styryl group. Among them, none substituent, 8 showed the highest FPTase inhibition activity$(pI_{50}=4.30)$. Particularly, the SAR equation could be formulated, showing a parabolic relationship between the activity and hydrophobicity(logP) where the optimal value$({\Sigma}logP)_{opt}$ was 3.915. And also the activity depends on the steric effect(Es > 0) with X-substituent and the resonance effect(R < 0) with electron donating Y-substituents. Based on the results of SAR analyses, the interactions between substrates and receptor, FPTase, could be assumed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.4
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• pp.348-357
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• 1988

The present work was undertaken to investigated the purification and characterization of polyphenol oxidase (PPO ; EC 1.10.3.1) in sweet potato, particularly the number of PPO isozymes, and PPO properties such as pH optimum, heat stability, substrate specificity, kinetics, and inhibitor studies. The purification achieved was 23.1 fold from crude extract with a yield of 41.5%. Eight PPO isozymes and twelve PPO isozymes were detected by disc polyacrylamide gel electrophoresis and isoelectric focusing, respectively. The specific activity of each isozyme separated by isoelectric focusing was in the range of $6,000{\sim}46,700U/mg$. This enzyme was sweet below $65^{\circ}C$ and the pH optimum of PPO occurred at 6.0-6.5. The substrate specificity of sweet potato PPO showed the high affinity toward the odiphenolic compounds. Km and Vmax for catechol were found to be 6.7 mM and $20{\triangle}A/min$, me protein, respectively. Inhibitor studies indicated that dithiothreitol was the most potent among the inhibitors used in the present work.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1248-1254
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• 1997

To measure antioxidative activities, the various extracts from RVS (Rhus Verniciflua Stokes) were tried out with either DPPH or thiocyanate method. Also we used the GO (Glucose Oxidase) 20 mU/mL hydroxyl radical system in mouse whole brain cell culture. Chloroform, n-hexane or ethanol were used as extract solutions which had different polarity respectively. In DPPH and thiocyanate method, the antioxidative activities of the crude ethanol extracts were stronger than other extracts. The crude ethanol extracts were fractionated 5 peaks by glass column. Among of them, antioxidative activity of peak II $(P_{II})$ was shown stronger than other fractions, a little for peak III $(P_{III})$ and peak IV $(P_{IV})$, and none for peak I $(P_I)$ and Peak V $(P_V)$. In the antioxidative effects of crude ethanol extracts (30 mg/mL), cell viabilities were evaluated $1\;{\mu}L\;(297\;{\mu}g/mL)$, $2\;{\mu}L\;(588\;{\mu}g/mL)$ of crude ethanol extracts 59%, 68% respectively. $10\;{\mu}L\;(2,727\;{\mu}g/mL)$ addition of crude ethanol extracts had 95% cell viabilities, 0.01% significant, comparing control. In addition, the compounds related to antioxidative effect of crude ethanol extract might be glycoproteins by means of SDS-PAGE. Comparison to antioxidative effects between several antioxidants (ascorbic acid, ${\alpha}-tocopherol$, catalase) $273\;{\mu}L/mL$ addition of crude ethanol extracts corresponds to $1\;{\mu}g/mL$ catalase in antioxidative effects.