• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.381-381
• /
• 2011

In this study, a TiO2 colloidal sol was synthesized by sol-gel process, which was used as a "glue" agent to enhance interconnection of TiO2 particles in low temperature process for plastic dye sensitized solar cell. The crystalline phase of this TiO2 glue is pure anatase with average particles size of 5 nm, which was characterized by powder X-ray diffraction and high revolution-TEM. The viscous alcoholic paste without any organic binder was prepared from the mixture of commercial P25 powder and glue. Paste composition and sintering process parameters were optimized for high photovoltaic performance based on low temperature process. The electrochemical impedance spectroscopy and photocurrent-photovoltage transient spectroscopy were also employed to investigate the mechanism of electron transport in this binder free TiO2 film system.

• Food Science and Biotechnology
• /
• v.18 no.1
• /
• pp.172-178
• /
• 2009

Fermented ginseng (FG) is an ethanol extract of ginseng radix processed with $\beta$-galactosidase. It was hypothesized that FG may exert anti-hyperlipidemic and anti-diabetic activities through modulating AMP-activated protein kinase (AMPK) in HepG2 human hepatoma cells. In this study, we showed that AMPK phosphorylation was stimulated by FG. These effects were abolished by pretreatment with an AMPK inhibitor, compound C. In addition, FG regulated the expression of genes associated with lipogenesis and lipolysis, thus causing suppression of hepatic triglyceride accumulation. In vivo study using db/db mice, FG reduced fasting plasma glucose, HbAlc, and insulin resistance index, when compared to diabetic control. FG also increased the phospho-AMPK and glucose transporter 4 (GLUT4) expressions in liver and skeletal muscle, respectively. In liver, expressions of lipogenic gene were decreased whereas expressions of lipolytic genes were induced, when compared to diabetic control. Taken together, we may suggest that FG ameliorates hyperglycemia and hyperlipidemia through activation of AMPK and could be developed as a health functional food or therapeutic agent for type 2 diabetic patients.

• Journal of Ginseng Research
• /
• v.36 no.1
• /
• pp.61-67
• /
• 2012

In the present study, effects of sun ginseng (SG) on the collagen synthesis and the proliferation of dermal fibroblast were investigated. Collagen synthesis was measured by assaying procollagen type I C-peptide production. In addition, the level of matrix metalloproteinase (MMP)-1 was assessed by western blot analysis. SG suppressed the MMP-1 protein level in a dose-dependent manner. In contrast, SG dose-dependently increased tissue inhibitors of MMP (TIMP)-1 production in fibroblasts. SG increased type I collagen production directly and/or indirectly by reducing MMP-1 and stimulating TIMP-1 production in human dermal fibroblasts. SG dose-dependently induced fibroblast proliferation and this, in turn, can trigger more collagen production. These results suggest that SG may be a potential pharmacological agent with anti-aging properties in cultured human skin fibroblast.

• Resources Recycling
• /
• v.13 no.2
• /
• pp.47-53
• /
• 2004

Waste aluminum dross is a major waste in the aluminum scrap smelters, and some metallic aluminum remains in the waste dross. In the previous study, waste aluminum dross was leached with sodium hydroxide solution to extract the remained aluminum into the solution, and aluminum hydroxide precipitate was recovered from the leached solution. A pilot plant was constructed and tested to demonstrate the developed technology. One thousand tons of waste aluminum dross could be processed, and about five hundred tons of aluminum hydroxide could be produced in the pilot plant. From the test run of the pilot plant, it was confirmed that the developed technology could be employed as a commercial scale and the produced aluminum hydroxide could be used for water treatment agent.

• Journal of Chest Surgery
• /
• v.23 no.3
• /
• pp.465-473
• /
• 1990

Glutaraldehyde have been used as the most effective cross-linking agent for stabilizing collagen fibers and preventing biodegradation. We processed bovine pericardium in a solution containing 0.625% glutaraldehyde,0.05M HEPES buffer and 0.26% magnesium chloride in saline. The glutaraldehyde-preserved bovine pericardium was implanted in 36 patients at Seoul National University Hospital during a 11-month period between May 1989 and March 1990. 24 were males and 12 females, with ages ranging from 6 months to 168 months [mean age of 43 months]. In 12 patients, the glutaraldehyde-preserved bovine pericardium was used for orthotopic reconstruction of the pericardial sac. In 24 patients. the glutaraldehyde-preserved bovine pericardium was heterotopically implanted.; pulmonary monocusp implant and RVQT [right ventricular outflow tract] patch widening were performed in 10 patients, pulmonary monocusp implant in 6, RVOT patch widening in 4, valved conduit in 2, conduit and pulmonary angioplasty in 1, and ventricular septation in l. With vascular suture techniques, the anastomoses were immediately tight. There was no bleeding from the needle holes and no oozing through bovine pericardium itself. During the follow-up period of up to 10 months, no infections of the glutaraldehyde-preserved bovine pericardium occurred and no bovine pericardium-related complications were observed in this series.

• Applied Chemistry for Engineering
• /
• v.30 no.5
• /
• pp.562-568
• /
• 2019

Cylindrical shape extrudates of calcium silicate hydrate (CSH) were prepared using different percentages of polyvinyl alcohol (PVA) / sodium alginate (SA) mixtures as binders and an aqueous solution containing 6% $H_3BO_3$ and 3% $CaCl_2$ was used as a cross linking agent. As the quantity of alginate increases, the phosphate removal efficiency and capacity were decreased. Among four different extrudate samples, the sample prepared by 8% PVA + 2% SA showed the highest phosphate removal efficiency (59.59%) and capacity (29.97 mg/g) at an initial phosphate concentration of 100 ppm and 2.0 g/L adsorbent dosage. Effects of the adsorbent dosage, contact time and initial phosphate concentration on the sample were further studied. The removal efficiency and capacity obtained by a 4.0 g/L adsorbent dose at an initial phosphate concentration of 100 ppm in 3 h were 79.38% and 19.96 mg/g, respectively. The experimental data of kinetic and isotherm measurements followed the pseudo-second-order kinetic equation and Langmuir isotherm model, respectively. These results suggested that the phosphate removal was processed via a chemisorption and a monolayer coverage of phosphate anions was on the CSH surface. The maximum adsorption capacity ($q_{max}$) was calculated as 23.87 mg/g from Langmuir isotherm model.

• Bulletin of the Korean Chemical Society
• /
• v.20 no.3
• /
• pp.301-306
• /
• 1999

Hepatitis C virus (HCV) has been known to be an enveloped virus with a positive strand RNA genome and the major agent of the vast majority of transfusion associated cases of hepatitis. For viral replication, HCV structural proteins are first processed by host cell signal peptidases and NS2/NS3 site of the nonstructural protein is cleaved by a zinc-dependent protease NS2 with N-terminal NS3. The four remaining junctions are cleaved by a separate NS3 protease. The solution conformations of NS4B/5A, NS5A/5B substrates and NS5A/5B inhibitor have been determined by two-dimensional nuclear magnetic resonance (NMR) spectroscopy. NMR data suggested that the both NS5A/5B substrate and inhibitor appeared to have a folded tum-like conformation not only between P1 and P6 position but also C-terminal region, whereas the NS4B/5A substrate exhibited mostly extended conformation. In addition, we have found that the conformation of the NS5A/5B inhibitor slightly differs from that of NS5A/5B substrate peptide, suggesting different binding mode for NS3 protease. These findings will be of importance for designing efficient inhibitor to suppress HCV processing.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.3
• /
• pp.111-117
• /
• 2021

The delivery problem on a graph is that of minimizing the object delivery time from one vertex to another vertex on a graph with m vertices using n various speed robot agents. In this paper, we propose two optimal solution algorithms for the delivery problem on a graph with time complexity of O(㎥n) and O(㎥). After preprocessing to obtain the shortest path for all pairs of the graph, our algorithm processed by obtaining the shortest delivery path in the order of the vertices with the least delivery time. Assuming that the graph reflects the terrain on which to solve the problem, our O(㎥) algorithm actually has a time complexity of O(㎡n) as only one preprocessing is required for the various deployment of n robot agents.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.64 no.3
• /
• pp.1-8
• /
• 2022

In this study, a farm map utilization strategy for sustainable agricultural environmental resource management was derived. In addition, it is intended to present an efficient method of providing farm map-related services. As a result of the demand survey, the additional information required for the farm map includes 29% of information on crops grown on farmland, 21% of management-related information such as the owner or business entity, 17% of topographical information including slope, 15% of agricultural water information, 17% of land status information, and the addition of functions. 2% was investigated. As a result of intensive interview survey, it was found that it can be used for information on crops cultivated by agricultural businesses, actual cultivated area by township, arable land consolidation division boundary, and management of agricultural promotion zones. The farm map can be used as basic data to efficiently manage agricultural environmental resources. Since the status of support for individual farms or lots, such as soil improvement agent support and organic fertilizer support, may belong to personal information, it can be processed and provided in units required by administration or policies, such as administrative boundaries, subwatersheds, and watersheds. It can serve as a basis for executing the direct payment currently supported only by individual farms, even in a community unit that manages environmental direct payments.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.1
• /
• pp.84-88
• /
• 2011

Some thermally processed foods have higher biological activities due to their various chemical changes during heat treatment. Especially, 5-hydroxymethylfurfural (HMF) is derived from dehydration of sugars and has been identified in processed garlic. The biological function of HMF have revealed as antisickling agent and thyrosinase inhibitor. This study was carried out to examine the formation of HMF and free sugars from the aged garlics when it is treated at 60 and $75^{\circ}C$ and different incubation periods from 7 to 35 days. HMF and free sugars from the hot-water extracts of aged garlics were analyzed with GC/MS, LC/MS, and HPLC. The amount of HMF was higher than at $75^{\circ}C$ and increasing incubation period. Among free sugars, the only fructose except glucose and sucrose was formed and converted to HMF at high temperature and long incubation period. However, fructose formed in low temperature during making of aged garlic was rarely converted to HMF. This result indicates that formation of HMF can be dependent on the temperature and incubation period for making aged garlic.