• The Korea Journal of Herbology
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• v.27 no.2
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• pp.85-91
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• 2012

Objective : Myeongganbo (MGB) composited with Hovenia Semen, Puerariae Radix and Dioscoreae Rhizoma is the prescription for protection of liver function. The purpose of this study was to investigate the effects of MGB extract against acetaminophen (APAP)-induced liver injury in mice. Methods : MGB extract was prepared by extracting with hot distilled water. The extract was freeze-dried following filtration through vacuum distillation system. Mice fasted for overnight were orally administrated with or without MGB extract of different doses (25-200 mg/kg/day). After 30 min, APAP was orally applied with a single dose (400 mg/kg). The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured in plasmas of mice. Glutathione (GSH), glutathione peroxidase GSH-px), cyclooxygenase-2 (COX-2) activity and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) level were investigated in liver homogenates. Liver sections were stained with haematoxylin & eosin, anti-TNF-${\alpha}$ and anti-mouse COX-2 antibodies. Results : APAP treatment remarkably increased AST and ALT activities in plasma but inhibited GSH and GSH-px levels in liver homogenates. Also, liver injury was significantly accelerated by APAP treatment. Furthermore, APAP remarkably elevated COX-2 activity and TNF-${\alpha}$ levels in liver homogenates. However, administration of MGB extract was able to counteract these effects. Histological studies provided supportive evidence for biochemical and molecular analysis Conclusions : These results suggest that MGB extract has potent hepatoprotective effect against APAP-induced liver injury, these properties may contribute to liver disease care.

• Korean Journal of Optics and Photonics
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• v.21 no.1
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• pp.33-37
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• 2010

We performed time-domain terahertz (THz) spectroscopy to determine optical constants of highly conductive carbon nanotube (CNT) films. The CNT films have been fabricated on a flexible plastic substrate by using spin-coating or vacuum filtration. We found that the transmission of THz waves can be controlled by manipulating the thickness of the films and by post-treatments. From amplitude and phase information of the transmitted THz waves, we obtain optical constants such as refractive indices and dielectric constants of the CNT films. The frequency dependent dielectric constants show good metallic behaviors, relevant to the Drude free electron models with high plasma frequencies. It is also found that the dielectric constants are higher for the acid-treated films. Finally, the frequency dependent dielectric constants which are free from substrate effects have been demonstrated by using CNT films deposited on cellulose membranes.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.197-205
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• 2011

Cellulose nanofibrils (CNF) with 50~100 nm diameter were manufactured from micro-size cellulose by an application of a high-pressure homogenizer at 1,400 bar. High strength nanopapers were prepared over a filter paper by a vacuum filtration from CNF suspension. After reinforcing and dispersing CNF suspension, hydroxypropyl cellulose (HPC) and polyvinyl alcohol (PVA)-based composites were tailored by solvent- and film-casting methods, respectively. After 2, 4, 6 and 8 passes through high-pressure homogenizer, the tensile strength of the nanopapers were extremely high and increased linearly depending upon the pass number. Chemical modification of 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) on the nanopapers significantly increased the mechanical strength and water repellency. The reinforcement of 1, 3, and 5 wt% CNF to HPC and PVA resins also improved the mechanical properties of the both composites.

• Herbal Formula Science
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• v.19 no.1
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• pp.207-217
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• 2011

Objectives : In a previous study, we have shown that Gagam-Gongjin-Dan(GGD) has an inhibitory effect on the ovalbumin-induced immune responses and a hepatoprotective effect on actaminophen-induced liver injury in Balb/c Mice. However, the possible anti-inflammatory effect of GGD extract for inflammatory mediators was not reported. Therefore, the purpose of this study was to investigate an inhibitory effects of GGD extract against lipopolysaccharides(LPS) induced inflammatory mediators in mouse peritoneal macrophages. Methods : GGD extract was prepared by extracting with methanol for 7 days. The extract was freeze-dried following filtration through vacuum distillation system. Accumulated nitrite, an oxidative product of nitric oxide(NO), was measured in the culture medium by the Griess reaction. The levels of prostaglandin $E_2(PGE_2)$, interleukin-$1{\beta}$(IL-$1{\beta}$), tumor necrosis factor-${\alpha}$(TNF-${\alpha}$) were measured by enzyme-linked immunosorbent assay. The expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2(COX-2) were measured by Western blot analysis. Results : GGD extract (50-$400\;{\mu}g$/ml) per se had no cytotoxic effect in LPS-stimulated peritoneal macrophages. GGD extract dose-dependently reduced NO, $PGE_2$, IL-$1{\beta}$ and TNF-${\alpha}$ production and COX-2 activity caused by stimulation of LPS. The levels of iNOS and COX-2 protein expressions were markedly suppressed by the treatment with GGD extract in a dose dependent manner. Conclusions : These results suggest that GGD extract has an anti-inflammatory effect against LPS-induced inflammatory mediators in peritoneal macrophages, these properties may contribute to inflammation disease care.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.25-31
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• 2017

Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.31.1-31.1
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• 2009

Carbon nanotubes (CNTs) are attractive material because of their superior electrical, mechanical, and chemical properties. Furthermore, their geometric features such as a large aspect ratio and a small radius of curvature at tip make them ideal for low-voltage field emission devices including backlight units of liquid crystal display, lighting lamps, X-ray source, microwave amplifiers, electron microscopes, etc. In field emission devices for display applications, the phosphor anode is positioned against the CNT emitters. In most case, light generated from the phosphor by electron bombardment passes through the anode front plate to reach observers. However, light is produced in a narrow depth of the surface of the phosphor layer because phosphor particles are big as much as several micrometers, which means that it is necessary to transmit through the phosphor layer. Hence, a drop of light intensity is unavoidable during this process. In this study, we fabricated a transparent cathode back plate by depositing an ultra-thin film of single walled CNTs (SWCNTs) on an indium tin oxide (ITO)-coated glass substrate. Two types of phosphor anode plates were employed to our transparent cathode back plate: One is an ITO glass substrate with a phosphor layer and the other is a Cr-coated glass substrate with phosphor layer. For the former case, light was radiated from both the front and the back sides, where luminance on the back was ~30% higher than that on the front in our experiments. For the other case, however, light was emitted only from the cathode back side as the Cr layer on the anode glass rolled as a reflecting mirror, improving the light luminance as much as ~60% compared with that on the front of one. This study seems to be discussed about the morphologies and field emission characteristics of CNT emitters according to the experimental parameters in fabricating the lamps emitting light on the both sides or only on the cathode back side. The experimental procedures are as follows. First, a CNT aqueous solution was prepared by ultrasonically dispersing purified SWCNTs in deionized water with sodium dodecyl sulfate (SDS). A milliliter or even several tens of micro-liters of CNT solution was deposited onto a porous alumina membrane through vacuum filtration. Thereafter, the alumina membrane was solvated with the 3 M NaOH solution and the floating CNT film was easily transferred to an ITO glass substrate. It is required for CNT film to make standing CNTs up to serve as electron emitter through an adhesive roller activation.

• Resources Recycling
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• v.28 no.4
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• pp.30-36
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• 2019

In this study, Li powder was recovered from the by-product of LNO ($Li_2NiO_2$) process, which is the positive electrode active material of waste lithium ion battery, through the $CO_2$ thermal reaction process. In the process of recovering Li powder, the $CO_2$ injection amount is 300 cc/min. The $Li_2NiO_2$ award was phase-separated into the $Li_2CO_3$ phase and the NiO phase by holding at $600^{\circ}C$ for 1 min. After this, the collected sample:distilled water = 1:50 weight ratio, and after leaching, the solution was subjected to vacuum filtration to recover $Li_2CO_3$ from the solution, and the NiO powder was recovered. In order to increase the purity of Ni, it was maintained in $H_2$ atmosphere for 3 hours to reduce NiO to Ni. Through the above-mentioned steps, the purity of Li was 2290 ppm and the recovery was 92.74% from the solution, and Ni was finally produced 90.1% purity, 92.6% recovery.

• The Korea Journal of Herbology
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• v.24 no.4
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• pp.127-135
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• 2009

Objectives : Gagam-Gongjin-dan (GGD) composited with Cervi parvum Cornu, Corni Fructus, Angelica gigantis Radix, Lycii Fructus, Dioscoreae Rhizoma, Citri Pericarpium, Gastrodiae Rihzoma, Agastachis Herba, Cassiae cortkex, Scutellariae Radix, Schisandrae Fructus has been traditionally used for chronic diseases or weakness after illness in oriental countries. However, little is known about the effects of methanol extract of GGD on immune responses to ovalbumin (OVA) plus alum. Therefore, the purpose of this study was to investigate the effects of GGD on immune responses to ovalbumin plus alum in Balb/c mice. Methods : In this study, the extract of GGD was prepared by extracting with methanol for 7 days. The extract was freeze-dried following filtration through vacuum distillation system. Mice were orally administrated with or without GGD extract of different doses (50-200 mg/kg/day) for 30 days. We examined the effects of GGD extract on the serum levels of total IgE, OVA-specific IgE, IgG1, IgG2a, and CTACK/CCL27 production and CCR10 expression in lymph node cells and body weight change and foot pad swelling responses in ovalbumin treated Balb/c. Results : The oral administration of GGD dose-dependently reduced the serum levels of total IgE, OVA-specific immunoglobulin (IgE, IgG1 and IgG2b) and CTACK/CCL27 production in ovalbumin treated BALB/c mice. The levels of CCR10 expression from lymph node cells of OVA treated mice were markedly suppressed by treatment with GGD in a concentration dependent manner. Furthermore, foot pad swelling responses were also markedly suppressed by GGD. However, body weight were significantly increased dose dependently by GGD treatment. Conclusions : These results suggest that GGD treatment suppresses immune responses to ovalbumin, and these properties may contribute to allergic disease care.

• Clean Technology
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• v.29 no.1
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• pp.46-52
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• 2023

Oxalic acid has been traditionally obtained via the oxidation of carbohydrates using nitric acid and catalysts. However, this process produces a variety of nitrogen oxides during oxidation and requires a separation process due to its various intermediates. These products and additional steps increase the harmfulness and complexity of the process. Recently, the electrochemical reduction of carbon dioxide into oxalic acid has been suggested as an environmentally friendly and efficient technology for the production of oxalic acid. In this electrochemical conversion system, zinc oxalate (ZnC₂O₄) is obtained by the reaction of Zn²⁺ ions produced by Zn oxidation and oxalate ions produced by CO₂ reduction. ZnC₂O₄ can then be converted to form oxalic acid, but this requires the use of a strong acid and heat. In this study, a system was proposed that can easily convert ZnC₂O₄ to oxalic acid without the use of a strong acid while also allowing for easy separation. In addition, this proposed system can also further convert the products into glycolic acid which is a high-value-added chemical. ZnC₂O₄ was effectively separated into Zn(OH)₂ powder and oxalate solution through a chemical treatment and a vacuum filtration process. Then the Zn(OH)₂ and oxalate were electrochemically converted to zinc and glycolic acid, respectively.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.111-118
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• 2023

MXene, a two-dimensional transition metal carbide or nitride, has recently attracted much attention as a lightweight and flexible electromagnetic shielding material due to its high electrical conductivity, good mechanical strength and thermal stability. In particular, the Ti-based MXene, Ti₃C₂T_x and Ti₂CT_x are reported to have the best electrical conductivity and electromagnetic shielding properties in the vast MXene family. Therefore, in this study, Ti₃C₂T_x and Ti₂CT_x films were prepared by vacuum filtration using Ti₃C₂T_x and Ti₂CT_x dispersions synthesized by interlayer metal etching and centrifugation of Ti₃AlC₂ and Ti₂AlC. The electrical conductivity and electromagnetic shielding efficiency of the films were measured after heat treatment at high temperature. Then, X-ray diffraction and photoelectron spectroscopy were performed to analyze the structural changes of Ti₃C₂T_x and Ti₂CT_x films after heat treatment and their effects on electromagnetic shielding. Based on the results of this study, we propose an optimal structure for an ultra-thin, lightweight, and high performance MXene-based electromagnetic shielding film for future applications in small and wearable electronics.