• The Journal of Internal Korean Medicine
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• v.31 no.1
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• pp.11-24
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• 2010

Objectives : This study was carried out to investigate the hepatoprotective effects of mixture with Hovenia dulcis Thunb (HDT) and Acer tegmentosum Maxim(ATM) on D-galactosamine-induced liver failure in rats. Methods : The animals were divided into 4 groups: control, with liver failure and no treatment; H1A1, with liver failure and oral treatment with HDT 1 and ATM 1; H1A2, with liver failure and oral treatment with HDT 1 and ATM 2; H1A4, with liver failure and oral treatment with HDT 1 and ATM 4. The animals were treated for 3 weeks and then examinations of change of body weight, aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transpeptidase ($\gamma$-GTP), total cholesterol, triglyceride, total bilirubin, superoxide dismutase (SOD), catalase, histopathologic change, and complete blood count (CBC) were performed. Results : All experimental groups had significantly decreased AST in serum and markedly increased activity of SOD as compared with the control group. H1A1, and H1A4 significantly decreased ALT in serum and H1A4 at 2 weeks was significantly higher on the change of body weight as compared with the control group. In histopathologic change of liver tissue by light microscopy, all experimental groups showed recovery effects of liver cells which were damaged by D-galactosamine. Conclusions : Based upon these results, it could be assumed that a mixture of HDT and ATM has hepatoprotective and antioxidative effects on D-galactosamine-induced liver failure. Therefore, a mixture of HDT and ATM might be utilized as a protective agent in therapy for liver diseases.

• Journal of Veterinary Clinics
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• v.28 no.1
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• pp.20-27
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• 2011

Hovenia dulcis Thunb (HDT) has been known folk medicine and has been used as therapeutic drug in the treatment of liver disease. Also it has been used as a detoxifying agents for alcoholic poisoning and promoting diuresis. However, there has not been any study on therapeutic effect of Hovenia dulcis extract on $CCl_4$ induced liver and kidney damage in rats. In this study, we report on therapeutic effects of Hovenia dulcis extract on $CCl_4$ induced liver and kidney damage in rats. Rats were divided into four groups of eighteen animals. Control group (DW) was administrated with distilled water 2.5 mL/kg per peritonial administration and then $CCl_4$ group (CCl) was administrated $CCl_4$ 2.5 mL/kg per peritonial administration, $CCl_4$+HDT extract group ($CCl_4$+HDT) was administrated HDT extrat (100 mg/kg) after $CCl_4$ 2.5 mL/kg administration, $CCl_4$+Silymarin group ($CCl_4$+Sily) was administrated Silymarin (50 mg/kg) after $CCl_4$ 2.5 mL/kg administration. The complete blood cell (CBC) count of RBC, WBC, PCV, Hb, MCH, MCV, MCHC and blood chemistry profile of AST, ALT, GGT, ALP, Total choloesterol, Tryglyceride, Total bilirubin, Amylase, Glucose, BUN, Creatinine, Lipase and pathologic changes were observed for 7 days after administration of D.W., $CCl_4$, $CCl_4$+HDT extract, $CCl_4$+Silymarin. The results are as follows : 1. RBC and PCV were significantly (p < 0.01) increased in all groups compared to D.W. but hemoglobin, MCH, MCV and MCHC were not showed significant difference during experimental periods. 2. AST, ALT, T-cholesterol, T-bilirubin, TG were significantly (p < 0.05) increased in all groups on day 3 compared to D.W. and were normal on day 7. 3. ALP was significantly (p < 0.05) decreased in $CCl_4$+HDT group on day 3 but Amylase was not showed significant difference during experimental periods. 4. BUN was significantly (p < 0.05) increased in $CCl_4$ group on day 7, but $CCl_4$+HDT group and $CCl_4$+Sily group were normal. Creatninie was significantly (p < 0.05) increased in $CCl_4$ group on day 3 and normal on day 7 but $CCl_4$+HDT group and $CCl_4$+Sily group were not showed significant difference during experimental periods.

• Journal of Sensor Science and Technology
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• v.21 no.3
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• pp.186-191
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• 2012

In this paper, we present a pH measurement method that uses a microcantilever-array-based biosensor system. It is composed of microcantilever array, liquid cell, micro syringe pump, laser diode array, position sensitive detector, data acquisition device, and data processing software. Four microcantilevers are functionalized with pH-sensitive MHA(mercaptohexadecanoic acid) as a probe, while three microcantilevers are functionalized with HDT(hexadecane thiol) as reference. We prepare PBS(phosphate buffered saline) solutions of different pH and inject them into the liquid cell with a predefined volumetric speed at regular time intervals. The functionalized mircocantilevers in the liquid cell deflect as a self-assembled monolayer on the microcantilever binds with probe molecules in the solution. The difference in deflection between the MHA-covered probe microcantilever and the HDT-covered reference microcantilever was used to compensate for thermal drift. The deflection difference clearly increases with increasing pH in the solution. It was shown that when the pH values of the PBS solutions are high, there were large variations in the deflection of microcantilevers, whereas there were small variations for low pH value. The experimental results show that the microcantilever array functionalized with MHA and HDT can detect pH value with good repeatability.

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1309-1312
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• 2009

Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

• Journal of the Korean Chemical Society
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• v.66 no.5
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• pp.349-361
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• 2022

Because hydrotreating (HDT) of FCC gasoline is one of the important processes used to prepare such gasoline for blending, the development of a catalyst for this process is of great interest. Currently, the industrial HDT of FCC gasoline consists of two stages and the creation of a new catalyst for one-stage HDT will make this process more efficient. Recently, our group has developed the CoMo/Al₂O₃-ASA catalyst and studied the influence of Si/Al ratio on the target reactions of HDT process. Despite the high selectivity and activity, the catalyst with ASA is not applicable in industry because of its low strength. The present work moves forward to study the influence of the ASA content in the catalyst support and clarify the possibility to develop the catalyst that combines high activity and selectivity in HDT reactions with successful performance. Here we show that the CoMo catalyst with ASA/Al₂O₃ molar ratio 1/1 in the support is the best combination for FCC gasoline hydrotreatment due to exceptional properties of the catalyst composition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.919-925
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• 2012

We tried to blend PLLA and PDLA at overall compositions to form PLA stereocomplexes (SC). The presence of the SC crystalline phase in the PLLA matrix was verified by differential scanning calorimetry (DSC). As a result, a various PDLA composition of the PLA SC blends can influence PLA SC formation. And the largest amount of PLA SC crystallites was formed when PLLA/PDLA ratio is 50/50. In addition, we have tried to do PLA SC toughening with two impact modifiers in 92/8, 85/15 ratio of PLLA/PDLA to enhance the mechanical properties such as impact strength. Thermal and mechanical properties of PLA SC were investigated by DSC, HDT, Izod impact tester and UTM. PLA SC formation decreased when 10-20 wt% of Strong120 (impact modifier) was added. On the other hand, there is no effect on PLA SC formation when 10-20% of Elvaloy (impact modifier) was added. HDT values dramatically increased over $100^{\circ}C$ with the addition of PDLA. However, HDT decreased as Strong120 and Elvaloy content increased. Finally, we could find well balanced composition of toughened PLA SC with 10wt% of impact modifier in flexural modulus and impact strength.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.409-411
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• 2014

Based on the first-principles computations, the nature of the microscopic geometry of the molecule-electrode contacts was addressed. The single-molecule junction was prepared by connecting hexanediothiolate (HDT) to Au(111) electrodes via one, two, and three Au adatoms having coordination number of one (CN1), two (CN2), and, three (CN3), respectively. The contact atomic structure and energy of the stretched Au-HDT-Au junction was observed. The analysis revealed that the contact geometry with lowest coordination number (CN1) is energetically more stable than CN2 and CN3.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.211-223
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• 1987

Head-down tilt (HDT) at $-6^{\circ}$ has been commonly used as the experimental model in both man and animals to induce the blood shift toward the head or central protion of the body, demonstrating similar physiological effect encountered in the weightlessness in the orbital flight. There are few reports about the physiological response upon the cardiovascular regulatory system or the tolerance to the $(-6^{\circ})$ HDT within a relatively short period less than 1 hour. Therefore, the purpose of this study way to observe the effects of $-6^{\circ}$ HDT on cardiovascular system within 30 minutes and to evaluate early regulatory mechanism for simulated hypogravity. Ten mongrel dogs weighing 8-12 kg were anesthetized with the infusion of 1% ${\alpha}-chloralose$ (100 mg/kg) intravenously, and the postural changes were performed from the supine to the $-6^{\circ}$ head-down Position, then from the head-down to the supine (SUP), and each posture was maintained for 30 minutes. Blood flow $({\dot{Q}})$ through common carotid and femoral arteries were determined by the electromagnetic flowmeter. Mean arterial pressure (MAP), heart rate (HR), respiratory rate , and pH, $P_{O_2}$, $P_{CO_2}$ and hematocrit (Hct) of arterial and venous blood were also measured. The peripheral vascular resistance was calculated by dividing respective MAP values by ${\dot{Q}}$ through both sides of common carotid or femoral arteries. The concentration of plasma epinephrine and norepinephrine was determined by Peuler & Johnson's radioenzymatic method. The results are summarized as follows: In the initial 5 minutes in $-6^{\circ}$ HDT, HR was significantly (p<0.05) increased and MAP slightly decreased. Although ${\dot{Q}}$ and carotid peripheral artery resistance were not significantly changed, ${\dot{Q}}$ through femoral artery was diminished and femoral peripheral artery resistance was elevated. In the SUP, the initial changes of MAP and HR were increased (p<0.05), but those of ${\dot{Q}}$ and peripheral vascular resistance through both common carotid and femoral arteries were not significant. After 10 minutes of each postural change in both HDT and SUP, MAP was maintained almost equal to that of the level of pretilting control. During 60 minutes of both postural changes of HDT and SUP, $P_{O_2}$ and Hct were not changed significantly. However pH tended to increase slowly and $P_{CO_2}$ was gradually decreased. The pH and $P_{CO_2}$ seemed to be related to the increased respiratory rate. Plasma epinephrine concentration was not changed significantly and plasma norepinephrine concentration was slightly decreased in the course of HDT and also at 10 minutes of SUP. However these concentration changes were statistically insignificant. From these results, it may be concluded that the effect of $-6^{\circ}$ HDT for 30 minutes on the cardiovascular system and plasma catecholamine levels of the dog is minimum and it is suggestive that the cardiovascular regulatory mechanism, possibly mediated by so called gravity receptors including baroreceptor and volume receptor, has been properly and adequately operated.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.238-238
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• 2006

Through ultra-violet photoemission spectroscopy in-situ experiment, 0.67 eV energy barrier between 1-hexadecanethiol (HDT)-modified gold and pentacene was observed, which was 0.03 eV smaller than the energy barrier between bare gold and pentacene despite HDT modified gold had 0.8 eV lower work function than that of bare gold. This result is opposed to the idea that increasing the work function a metal decreases the energy barrier. This can be explained by two factors. One is the absence of interface dipole, which is observed in pentacene deposited on gold. The other is reduced ionization energy which can be explained through polarization energy or electronic splitting of molecular orbital with more crystalline structure observed through X-ray diffraction patterns.

• Journal of Veterinary Clinics
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• v.27 no.4
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• pp.366-373
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• 2010

Diabetes mellitus (DM) is one of the highest morbidity and mortality diseases and is a state of increased oxidative stress. This study was carried out to evaluate anti-oxidant activities of Hovenia dulcis Thunberg in streptozotocin (STZ)-induced diabetic rats. Eighty Sprague-Dawley rats, 6 week-old, were divided into 3 groups at 12hours after STZ induction; Diabetic control group (DW per os DC group), Glibencliamide group (5 mg/kg glibenclimide per os, GLI group) and Hovenia dulcis group (100 mg/kg Hovenia dulcis Thunberg water extract per os HDT group). Normal control group (NC group) was just injected with DW instead of STZ. On day 5, superoxide dismutase (SOD) and catalase activities of HDT group were significantly (P < 0.05) increased compared with DC group and glutathione peroxidase activities of HDT group was more increased than DC group but there was no significant difference.