• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2009.04a
• /
• pp.470-471
• /
• 2009

• Journal of KSNVE
• /
• v.8 no.4
• /
• pp.596-602
• /
• 1998

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.5
• /
• pp.955-959
• /
• 2002

To test the protective effect of herbal medicine on myocardial damage against oxygen free radical-induced myocardiotoxicity, cytotoxicity was examined using MTT, Beating rate and TSARS assay in the presence of water extract of Rhizoma Coptidis. Myocardial toxicity was evaluated in neonatal rat myocardiocytes in cultures. The results of these experiments were obtained as follows: Xanthine oxydase/hypoxanthine resulted in a decrease in viability, beating rate and in a increase in lipid peroxidation in Cultured myocardial cells. Rhizoma Coptidis water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as increases in beating rate. Rhizoma Coptidis water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as decreases in lipid peroxidation. These results show that xanthine oxydase/hypoxanthine elicits toxic effects. in cultured myocardial cells derived from neonatal rat, and suggest that water extract of Rhizoma Coptidis is very effective in the prevention of xanthine oxydase/hypoxanthine-induced cardiotoxicity.

• Journal of the Korean Society of Costume
• /
• v.17
• /
• pp.137-148
• /
• 1991

The use of bark cloth, made of the inner bark of certain trees, was widespread along tropical zones from the Africa to the Hawaii encompassing the globe. They include Malaysia, Indonesia, New Guinea, Polynesian Islands and South America. Among them the Hawaiian bark cloth, named Kapa(pronounced as tapa) was rated as the best quality and most admired. It has variety in designs and colors as well as the most sophistcated production methods. The distinct processes of kapa making are composed of two stages. The first is called first beating and it is a preparatory stage to beat the sea-water soaked bast. It was done with a round beater on a stone anvil. The second beating process was carried out with the squared beater and wooden anvil. The strips from the first beating was soaked again in the water and then beaten lightly to break up fibers. The craftmen laid a bundle of strips over the anvil and beat it into pieces of kapa. The second beater of Hawaii was the most characteristic one among bark cloth producing countries. On their surfaces were the engraved patterns, which were creation of theirs. These distinguished designs enabled them to produce the kapa with the thinner and finer texture and an elaboration of impressed designs known as "watermaks". The Hawaiian culture was self-sufficient one : Everything they used was of their own creation until 19th century. Among their inventions of printing designs on kapa are three most important and distinguished processes. They are the overlaying, the cord snapping and the block printing techniques. Their inventiveness as well as self sufficient environment made it possible to develop their fine art of the kapa making. It is said that the mass producing and cheap western technology of loom forced them to gradually abandon their traditional art and as a result this fine and valuable legacy of Hawaiian traditional kapa making technique is all but disappeared. However it is encouraging and heart warming to find that some of the people as well as specialized researchers pined together to form a group to try to reproduce the old kapa and study the traditional art. They consider the kapa as an expression of the ethnic identity with Hawaii's heritage as well as valuable art of human history.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.1
• /
• pp.59-65
• /
• 2015

In this study, we evaluated optimum condition of enzyme with pH and temperature for preparation of microfibillated cellulose(MFC). Well-known endo-glucanase, three enzymes were used and CMC was used for substrate. Enzyme activity was evaluated using DNS method and absorbance with UV/VIS spectrophotometer. The enzyme shown the greatest activity was reacted with pulps at optimum condition for 1 hour and treated pulps beated until 100 mL CSF. Enzyme B and Enzyme L was the higher enzyme activity below 0.1% concentration and Enzyme N was the lowest enzyme activity. At various pH and temperature conditions, enzyme activity of Enzyme B was higher than the others at the same concentration. Especially enzyme activity at $50^{\circ}C$ of Enzyme B was almost not changed over pH 6.0. Optimum condition of three enzyme was pH 6 or pH 7 and $50^{\circ}C$ or $60^{\circ}C$. Also beating efficiency of enzyme treated pulps with Enzyme B is 55.6%.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.6
• /
• pp.1117-1121
• /
• 2002

To test the protective effect of herbal medicine on myocardial damage against oxygen free radical-induced myocardiotoxicity, cytotoxicity was examined using MTT, Beating rate and DNA synthesis assay in the presence of water extract of three kinds of Radix Rehmanniae. Myocardial toxicity was evaluated in neonatal rat myocardiocytes in cultures. The results of these experiments were obtained as follows : Xanthine oxydase/hypoxanthine resulted in a decrease in viability, beating rate and DNA synthesis in cultured myocardial cells. Radix Rehmanniae Recens(生地黃, RRR) water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as increases in beating rate. Radix Rehmanniae Preparat(熟地黃, RRP) water extract shows effects of protection from the cardiocyte toxicity induced by xanthine oxydase/hypoxanthine treatment such as increases in DNA synthesis. These results show that xanthine oxydase/hypoxanthine elicits toxic effects in cultured myocardial cells derived from neonatal rat, and suggest that water extract of three kinds of Radix Rehmanniae is very effective in the prevention of xanthine oxydase/hypoxanthine-induced cardiotoxicity.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.2
• /
• pp.77-82
• /
• 2011

The changes in the wet pressing response of old corrugated container(OCC) stock depending on the beating treatment and the addition of polymer aids were investigated with laboratory roll press instrument. Two types of polymer aids, such as high molecular weight polymer with low charge density and low molecular weight polymer with high charge density, were applied in this study. The more beaten OCC stock showed the lower dryness after wet pressing. The addition of polymer aids had great influences on the wet pressing efficiency and paper properties. The dryness after wet pressing was increased by the addition of polymer aids, but the pattern of changes in dryness were different depending on the type of polymer and the properties of stock. The higher molecular weight polymer aids showed the greater increase in the dryness. The properties of paper such as air permeability, bulk, formation, tensile strength were also greatly affected by the addition of polymer aids.

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.4
• /
• pp.103-110
• /
• 2001

Bio-kraft pulping of Populus alba${\times}$glandulosa pretreated with white-rot fungus, Phanerochaete chrysosporium KCCM 34740, was investigated The biopulping efficiency was evalued based on fungal pretreatment time and properties of bio-kraft pulp (pulp yield, freeness, WRY, kappa number and brightness) in comparison to the controls. Pretreatment of poplar wood chips with Phanerochaete chrysosporium KCCM 34740 for 10days resulted in a some increase in screened yield (by 2%). According to increase of fungal incubation time, decrease in freeness (CSF) and increase in WRY were observed And bio-kraft pulping also led to improvement of physical properties of handsheet. As a result of bio-beating effect, we expect the saving of chemicals in kraft cooking process and energy consumption in beating process.

• Journal of Korean Association for Spatial Structures
• /
• v.20 no.4
• /
• pp.149-158
• /
• 2020

The governing equation for a dome-type shallow spatial truss subjected to a transverse load is expressed in the form of the Duffing equation, and it can be derived by considering geometrical non-linearity. When this model under constant load exceeds the critical level, unstable behavior is appeared. This phenomenon changes sensitively as the number of free-nodes increases or depends on the imperfection of the system. When the load is a periodic function, more complex behavior and low critical levels can be expected. Thus, the dynamic unstable behavior and the change in the critical point of the 3-free-nodes space truss system were analyzed in this work. The 4-th order Runge-Kutta method was used in the system analysis, while the change in the frequency domain was analyzed through FFT. The sinusoidal wave and the beating wave were utilized as the periodic load function. This unstable situation was observed by the case when all nodes had same load vector as well as by the case that the load vector had slight difference. The results showed the critical buckling level of the periodic load was lower than that of the constant load. The value is greatly influenced by the period of the load, while a lower critical point was observed when it was closer to the natural frequency in the case of a linear system. The beating wave, which is attributed to the interference of the two frequencies, exhibits slightly more behavior than the sinusoidal wave. And the changing of critical level could be observed even with slight changes in the load vector.

• The Korean Journal of Physiology and Pharmacology
• /
• v.25 no.2
• /
• pp.159-166
• /
• 2021

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.