• ETRI Journal
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• v.24 no.5
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• pp.398-400
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• 2002

Using $Cr_2O_3$ thin film, we developed a novel etch-stop technique for the protection of silicon surface morphology during deep ion coupled plasma etching of silica layers. With this technique we were able to etch a silica trench with a depth of over 20 ${\mu}m$ without any damage to the exposed silicon terrace surface. This technique should be well applicable to fabricating silica planar lightwave circuit platforms for opto-electronic hybrid integration.

• Proceedings of the KIEE Conference
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• 2007.11a
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• pp.188-189
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• 2007

Axial magnetic field was applied into the hollow anode of plasma torch for the purpose of extension of electrode lifetime. The average arc voltage increased because the arc column became longer, the arc voltage ripple frequency became low. The steady state of arc voltage was removed by applied magnetic filed. The lifetime of electrode was over 1000 hours which is 100 times longer than operation without magnetic field.

• The Korean Journal of Physiology
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• v.22 no.2
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• pp.273-280
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• 1988

This study was undertaken to investigate the effect of the medial amygdaloid nucleus on the pancreatic exocrine secretion and plasma secretin concentration in 44 male albino rats. Twenty-three rats in which the medial amygdaloid nucleus was damaged bilaterally by radio frequency a.c. through stereotaxically inserted electrodes (medical amygdaloid group, MA) and twenty-one rats which received the same operation without damage (operated control, OC), were prepared. Under urethan anesthesia, 0.01 N hydrochloric acid (HCl) or physiological saline (0.9% NaCl) was infused at a rate of 0.18 ml/min into the duodenum for 20 minutes. Pancreatic jucie was collected for the 20 min infusion period. After collection of pancreatic juice, blood was sampled from the abdominal aorta for the radioimmunoassay of plasma secretin concentration. In the MA group, the exocrine pancreatic secretory response to 0.01 N HCI as well as saline infusion was significantly inhibited compared with that in the OC group. The pancreatic protein output of the MA group significantly decreased after the saline infusion and tended to decrease after the 0.01 N HCI infusion, compared with that of the OC group. However, there was no significant difference in plasma secretin concentration between the two groups. Therefore it is strongly suggested that the rat medial amygdaloid nucleus has a facilitatory influence on both basal and acid-stimulated pancreatic exocrine secretion, but the releasing mechanism of secretin appears not to be involved in the influence.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.181-189
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• 2011

Cryopreservation protocols induce partially irreversible damage to mammalian sperm plasma membranes. Previous studies have indicated that adding cholesterol to the plasma membrane, as cholesterol-loaded-cyclodextrins, improves cryosurvival of sperm. Therefore, the purpose of this study was to determine if treating sperm of Markhoz bucks with cholesterol-loaded-cyclodextrins (CLC) (0, 0.75, 1.5, 2.25 and 3 mg/ml diluted $240{\times}10^6$ sperm/ml) in Tris-citric acid-glucose diluents with and without egg yolk (containing 5% glycerol) would improve the post-thaw sperm quality. The motion characteristics were evaluated with a Computer Assisted System Analyzer (CASA); acrosome integrity and vitality were measured with the triple-stain technique. Samples were recovered before and after freezing by means of putting straws into $37^{\circ}C$ water for 30 sec and then parameters were assessed. The results showed that the treatments significantly affected motility, progressive motility, recovery rate, curvilinear velocity, beat cross frequency, live sperm with reacted acrosome, live sperm with unreacted acrosome, dead sperm with reacted acrosorne, and dead sperm with unreacted acrosome during freezing (p<0.05). However; no significant differences were found for average path velocity, straight line velocity, amplitude of lateral head displacement, straightness and linearity (p>0.05). The best results were observed for extender containing 2.25 mg/ml ($240{\times}10^6$ sperm/ml) CLC supplemented with 2.6% egg yolk. In conclusion, the findings of this study indicate improved Markhoz sperm viability and motility following treatment in the presence of egg yolk.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.346-351
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• 2004

This study was carried out to examine the antioxidant effects of a mixture of mulberry leaves and silkworm powder in plasma and liver of streptozotocin-induced diabetic rats. Sprague-Dawley male rats weighing 100$\pm$10 g were used and their diets were supplemented with $0.4\%$ (4 g/kg) of the mixtures. Experimental groups were diabetic rats without supplements (DM group) or with a combination of the supplements: $100\%$ mulberry leaves (M group), $25\%$ silkworm powder mixed with mulberry leaves (25SM group), $50\%$ silkworm powder mixed with mulberry leaves (50SM group), $75\%$ silkworm powder mixed with mulberry leaves (75SM group) or $100\%$ silkworm powder (100S group). The rats were fed experimental diets and water ad libitum. All animals were injected with streptozotocin at the $3^{rd}$ week for inducing diabetes and were sacrificed on $9^{th}$ day thereafter. Hepatic xanthine oxidase (XOD) activity significantly decreased in the mixture supplemented groups compared to the DM group. Hepatic superoxide dismutase (SOD) activity was not significantly different among any of the experimental groups, but glutathione peroxidase (GSH-px) activity increased in the mixture supplemented groups compared to the DM group. In particular, it was the highest in the 50SM group. The hepatic TBARS values were lower in all the mixture supplemented groups than in the DM group, and it was as lowest when ratio of mulberry leaves to silkworm powder was highest. Hepatic lipofuscin contents were similar with the TBARS value. In conclusion, the mixtures containing silkworm powder reduced oxidative damage by strengtbening the antioxidative system and suppressing oxidative stress in the STZ-induced diabetic rat. The 1:1 blend of silkworm powder and mulberry leaves was the most effective combination for antioxidant activity.

• Development and Reproduction
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• v.23 no.1
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• pp.11-19
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• 2019

The study was conducted to investigate the effects of alpha-linolenic acid (ALA) combined with bovine serum albumin (BSA) or methyl-beta-cyclodextrin (MBCD) on plasma and acrosomal membrane damages, mitochondrial activity, morphological abnormality, motility, and oxidative stress in frozen-thawed boar sperm. In previous our study, 3 ng/mL ALA had been shown protective effect during freezing process of boar sperm. Therefore, we used 3 ng/mL ALA in present study and ALA was combined with same molar ratio of BSA or MBCD (ALA+BSA and ALA+MBCD, respectively). To confirm the effect of two carrier proteins, same volume of BSA and MBCD without ALA were added during cryopreservation. Membrane damage, mitochondrial activity, reactive oxygen species (ROS) and lipid peroxidation (LPO) levels were measured using flow cytometry, and movement of sperm tail as motility parameter and morphological abnormality were observed under light microscope. In results, all of sperm parameters were enhanced by ALA combined with BSA or MBCD compared to control groups (p<0.05). Mitochondrial activity, morphological abnormality, ROS and LPO levels in ALA+BSA or MBCD groups were no significant difference compared with ALA, BSA and MBCD treatment groups. On the other hand, plasma and acrosomal membrane intact, and sperm motility in ALA+MBCD group were higher than single treatment groups (p<0.05), whereas ALA+BSA did not differ. Our findings indicate that carrier proteins such as BSA and MBCD could improve the effect of ALA during cryopreservation of boar sperm, and treatment of ALA with carrier proteins enhance membrane integrity, mitochondrial activity through reduction of ROS-induced LPO.

• Preventive Nutrition and Food Science
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• v.21 no.4
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• pp.378-383
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• 2016

Diabetic kidney disease is the most common and severe chronic complication of diabetes. The leaf of Diospyros kaki Thumb (persimmon) has been commonly used for herbal tea and medicinal purposes to treat a variety of conditions, including hypertension and atherosclerosis. However, the effect of persimmon leaf on kidney failure has not been investigated. This study aimed to examine the role of persimmon leaf in protecting the diabetes-associated kidney damage in a mouse model of type 2 diabetes. Mice were fed either a normal chow diet with or without powered persimmon leaf (5%, w/w) for 5 weeks. In addition to kidney morphology and blood markers of kidney function, we assessed levels of oxidative stress markers as well as antioxidant enzymes activities and mRNA expression in the kidney. Supplementation of the diet with powered persimmon leaf not only decreased the concentration of blood urea nitrogen in the plasma but also improved glomerular hypertrophy. Furthermore, the persimmon leaf significantly decreased the levels of hydrogen peroxide and lipid peroxide in the kidney. The activities of superoxide dismutase, catalase, and glutathione peroxidase and the mRNA expression of their respective genes were also increased in the kidney of persimmon leaf-supplemented db/db mice. Taken together, these results suggest that supplementation with the persimmon leaf may have protective effects against type 2 diabetes-induced kidney dysfunction and oxidative stress.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1849-1851
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• 1999

The PDP(Plasma Display Panel) barrier rib was fabricated by focused $Ar^+$ laser ($\lambda$=514nm) and Nd:YAG($\lambda$=532, 266 nm) laser irradiation. The depth of the etched groove increases with increasing a laser fluence. and decreasing a scan speed. Using the second harmonic of the Nd:YAG laser, the threshold laser fluence was $6.5mJ/cm^2$ for the sample of PDP barrier rib dried at $120^{\circ}C$. The thickness of $150{\mu}m$ of the sample on the glass was etched without any damage on the glass substrate by fluence of $19.5J/cm^2$. The barrier rib sample on hot plate was etched by Nd:YAG laser(532 nm) as increasing a temperature of the sample. In this case, the etch rate was $95{\mu}m/s$, $190{\mu}m/s$ at room temperature, $175^{\circ}C$ respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.394-396
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• 2008

기존의 PECVD에서 문제시 되고 있는 플라즈마에 의한 박막손상과 $300^{\circ}C$ 이상의 증착온도 등의 단점을 보완한 증착 기술로 중성입자 빔 (Hyper-thermal neutral beam ; HNB)을 이용한 저온 증착방법에 대한 연구를 진행하였다. 중성빔을 이용하여 HNB sputtering 방법과 $SiH_4$와 Ar, $H_2$ 가스를 이용한 HNB CVD 방법으로 a-Si 박막 제작에 대한 연구를 진행하였고, HIT(heterojunction with Intrinsic Thin layer) cell 태양전지를 만들고자 기본적인 박막 증착과 박막 특성 및 계면특성 등의 분석을 실시하였다. 유리기판과 p-type Si 기판 위에 a-Si 및 nc-Si 박막을 증착하였으며, TEM, FTIR, Raman, IV 측정 등을 통해 그 특성을 분석하여 HNB의 특성 및 효과를 규명하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.2
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• pp.20-27
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• 2022

Hypergolic propellant ignited spontaneously when fuel and oxidizer contact without ignition system. Due to this characteristic, the risk of accidents is high when new propellants are evaluated. Prevention of accidents is very important because the damage can be large when the accident occur. In this work, we proposed non-ignition evaluation method which can replace conventional ignition evaluation method by using microreactor. The reactor was fabricated by MEMS. The heat of reaction as according to fuel and NaBH₄ was estimated. At the condition of highest heat of reaction ignition was observed by drop test.