• Restorative Dentistry and Endodontics
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• v.20 no.1
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• pp.316-327
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• 1995

The purpose of this study was to evaluate canal shaping ability and canal angulation change of K-file, straight endosonic K-file and pre curved endosonic K-file. Twenty staight canals and thirty curved canals were selected and divided into five groups according to canals curvature and canal instrumentation method. VI group was prepared by straight endosonic K-file and H1 group by K-file in straigt canals. V2 group was instrumented by straight endosonic K-file, V3 group by pre curved endosonic K-file and H2 group by precurved K-file in curved canals. Radiographs of canals were obtained before and after canal shaping. And postoperative radiographs were compared with preoperative radiographs using superimposition method. The results obtained were as follows ; l. In straight canals, K-file group demonstrated lager percentage of canal enlargement than endosonic K-file group on facial view, but reverse results exhibit on mesial view. 2. In curved canals, precurved K-file group showed largest percentage of canal enlargement, followed by precurved endosonic K-fine group and straight endosonic K-file group was smallest. 3. Percantage of canal enlargement at convex side was greater than at concave side in apical portion of each group. Especially in straight endosonic K-file group, percantage of canal enlargement at convex side and concave side showed sharply difference. 4. In angulation change, the straight endosonic K-file group exhibited the greatest its change, followed by precurved endosonic K-file group and precurved K-file group was the least. Above results suggest that K-file is more effective endodontic instrument than endosonic K-file, and that precurved file is effective for canal shaping in curved canal.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.313-316
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• 2004

Ultrasonographic studies were conducted on eight Murrah buffaloes daily from day 6 postpartum (pp) onwards till day 77 pp to monitor changes in the cervix, uterine horn and ovarian follicular growth and development. The mean size of horn and cervix on day six ($9.07{\pm}0.74$ and $8.58{\pm}0.00cm$) decreased significantly to $4.09{\pm}0.09$ and $3.56{\pm}0.08cm$ by day 27 pp, respectively. Follicles in 50% of the buffaloes ovulated within 24 to 54 days pp and the size of the largest follicle on different days increased to more than 5 mm. The remaining 50 percent of animals ovulated after 65 days postpartum. Large size follicles (>8.5 mm) appeared in six out of eight buffaloes between 10 to 30 days pp and five animals had ovulated during early postpartum period. Waves pattern of follicular growth was observed during early postpartum period. Ovulatory follicles growth rate was more than the anovulatory follicles and increase in size was more as compared to the subordinate follicle. Anovulatory follicles persisted for longer period. Mean size of large follicle was more from day 6 to 41 pp and again from 50 to 65 pp in cyclic animals. Second large follicle were large during early postpartum (18days), thereafter, its size was more in acyclic animals. Small follicles population was less in cyclic animals upto day 50 postpartum. Mean medium size follicle growth pattern did not differ in cyclic and acyclic groups. Large size follicle number was more in cyclic group (5/8) during 14 to 20 days postpartum. Presence of large follicles (>8.5 mm) showed initiation of ovarian activity.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.307-316
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• 2016

Objectives: In general, NIOSH method 5506 is most widely used for the occupational exposure measurement of PAHs, but 2-4 ring PAHs have poor desorption efficiency, especially for a filter. The purpose of this study was to determine a method to increase the desorption efficiency of 16-PAHs using an ultrasonic extraction procedure. Methods: Test samples prepared spiked XAD-2 tubes and PTFE filters in the range of $0.01-1.0{\mu}g/mL$ for desorption efficiency study. Four different extraction solvents, acetonitrile, acetone, tetrahydrofuran and dichloromethane, were tested in order to select the most suitable solvent for the extraction of the 16 PAHs. The addition of dimethyl sulfoxide and sonication time were considered in order to determine the method with the highest extraction efficiency. All samples were made in three sets and analysis was replicated seven times by HPLC. Results: Acetonitrile and acetone were the optimized as an extraction solvent and desorption efficiency of 2-ring PAHs such as naphthalene, acenaphthylene were increased 3~19% with dimethyl sulfoxide for XAD-2. Acetone was the best extraction solvent for PTFE filter and the desorption efficiency was increased 3~13% for 2- to 4-ring PAHs. The optimum sonication time was 60 minutes and desorption efficiency increased with extraction time. Conclusions: As a result, the best extraction solvent was acetone with dimethyl sulfoxide for ultrasonic extraction procedure and the desorption efficiency of this method was better than NIOSH 5506's. This study could be applied as a method for occupational exposure measurement of PAHs.

• Journal of Biomedical Engineering Research
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• v.26 no.3
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• pp.139-144
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• 2005

An implantable microphone that can be utilized as part of a totally implantable hearing aid is designed and implemented. The proposed microphone is implanted in the center of the pinna, and designed to ensure the speech frequency range and the appropriate sensitivity. The characteristics of the proposed microphone are evaluated using a finite element analysis (FEA). The microphone is composed of a small electric condenser microphone, titanium case 6.2mm in diameter and 3mm high, and $10{\mu}m$ SUS316L vibrating membrane in contact with hypodermic tissue to maintain the sensitivity of the microphone. The microphone components are all made of biocompatible materials, then the assembled microphone is hermetically sealed using a polymer and ceramic. Experiments with the fabricated microphone confirm an operational bandwidth of up to 5kHz without any decline of sensitivity in 6mm of hypodermic tissue.

• Korean journal of food and cookery science
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• v.30 no.3
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• pp.307-316
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• 2014

This study was carried out in order to investigate the quality characteristics of baguette with different amounts of yeast and fermented rice bran sourdough(Control: Yeast 30 g + Fermented rice bran sourdough 0 g, A sample: Yeast 20 g + Fermented rice bran sourdough 150 g, B sample: Yeast 10 g + Fermented rice bran sourdough 300 g, C sample: Yeast 0 g + Fermented rice bran sourdough 450 g). The pH of fermented rice bran sourdough by fermentation time was decreased as the fermentation time was longer. The pH of baguette dough was decreased as the fermented rice bran sourdough increased; the volume was the highest in control at the 1st fermentation, and in the B sample at the 2nd fermentation. The weight of baguette was the highest in the C sample, and the volume and specific volume were the highest in the B sample. The microstructure of the cross section analysis indicated that the air cell of baguette crumb was large and regular in the B sample. The moisture content and water binding capacity were the highest in the B sample, although significantly different. The L value was decreased as there was an increasing addition ratio of fermented rice bran sourdough; further, the a and b values were decreased with an increase in baguette volume. Hardness, gumminess and chewiness were decreased as volume and specific volume were increased; yet, springiness was increased. According to the result of the sensory evaluation, the flavor, taste, appearance and texture were the highest in the B sample.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.310-316
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• 2020

In this study, the stability and EMP shielding performance of metal-based industrial by-products aggregates with excellent conductivity and easy procurement to be used as concrete aggregates for EMP shielding are evaluated. The industrial by-products are electronic-arc-furnace oxidizing slag, copper smelting slag, and ferro-moldibdenum. The composition analysis of aggregates and aggregate stability are evaluated. As a result of the experiment, ferro-moldibdenum is shown to have l ow stability as an aggregate due to its high Free-CaO. The remaining aggregates are evaluated to be safe to use as aggregates for concrete. In addition, industrial by-products aggreagate-specimens excluding ferro-moldibdenum are shown higher compressive strength than the plain specimen. The recycle aggregates, electronic-arc-furnace oxidizing slag and copper smelting slag, are shown excellent EMP shielding performance, the EMP shielding performance is expected to increase if the average particle diameter of the aggregate is small or evenly distributed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.3
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• pp.309-316
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• 2010

In this study, a digital particle holographic system and its application to channel-flow measurements were investigated. A double-exposure hologram recording system that is capable of recording digital holograms in a short time interval was developed. A correlation coefficient method was used to determine the focal plane of particles. The Wiener filter was used to remove noises and improve image quality. Two-threshold and image segmentation methods were used for binary image transformation. The cross-correlation method was used for particle pairing. The developed system was employed to study channel flow fields, and the axial velocities of channel flow were measured. The measurement errors are acceptable, and this proves the feasibility of using the digital particle holographic system as a good tool for flow-field measurements.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.308-316
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• 2006

Objectives Despite considerable advances in technique, experience and skill, the precise place of surgery in the treatment of facial nerve injury remains uncertain. We designed a facial nerve crush injury model in rats and evaluated the recovery of crushed nerve which is the most common injury type of facial nerve using adenovirus vector mediated in vivo gene transfer of Brain derived neurotrophic factor(BDNF). Materials and methods In 48 Sprague Dawley rats, we made a facial nerve crush injury model to main trunk before the furcation, and injected a $10^{11}$pfu adenoviral BDNF in experimental group(BDNF adenoviral injection group; ad-BDNF) and $3{\mu}l$ saline in control group(Saline injection group; saline). After a period of regeneration from 10 to 40 days, nerve regeneration was evaluated with functioinal test (vibrissae and ocular movement), electrophysiologic study(threshold, peak voltage, conduction velocity) and histomorphometric study of axon density. Results Vibrissae and ocular movement, threshold and conduction velocity improved as time elapse in both group, however axon density was increased significantly only in experimental group. Functional test in 10 days and 20 days showed no difference between experimental group and control group. Vibrissae movement, threshold, conduction velocity and axon density in 30 days revealed that the regeneration in quality of experimental group was significantly superior to that of control group. Conclusion In general, there is tendency for nerve regeneration in experimental group (BDNF-adenovirus injection group) during 40 days, functional recovery was detected successfully after facial nerve crush in 30 days postoperatively.

• Corrosion Science and Technology
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• v.9 no.6
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• pp.331-337
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• 2010

This study compared the macro and micro electrochemical characteristics at the local area of welding metal on dissimilar welding parts for type 304 stainless steel (SS) and type 316L SS. The materials are used for double wall gas pipe of duel fuel engine for a ship. The various potentiodynamic experiments were performed several times in 10% ${H_2C_2O_2}{\cdot}{H_2O}$ solution using macro and micro methods, respectively. The micro electrochemical experiments conducted to resolve at local area on cross-section of dissimilar welding materials by micro-droplet cell device. The micro-droplet cell techniques can be used almost electrochemical experiments to resolve corrosion characteristics of the limited electrode area of the metallic surface between wetted spot of working electrode and tip of sharpened capillary tube. The results of macro electrochemical experiments show that resistance of active dissolution reaction at welding zone was high due to low current density by formation of passivation protection film at passive region. According to the micro electrochemical experiment, the corrosion current density of welding zone and bond zone were relatively high.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.316-325
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• 2017

Background: Ginseng essence (GE) is a formulation comprising four medicinal and edible herbs including ginseng (Panax ginseng), American ginseng (Panax quinquefolius), lotus seed (Nelumbo nucifera), and lily bulb (Lilium longiflorum). This study was aimed at investigating the hepatoprotective effect of GE against carbon tetrachloride ($CCl_4$)-induced liver injury in rats. Methods: We treated Wistar rats daily with low, medium, and high [0.625 g/kg body weight (bw), 1.25 g/kg bw, and 3.125 g/kg bw, respectively] doses of GE for 9 wk. After the 1st wk of treatment, rats were administered 20% $CCl_4$ (1.5 mL/kg bw) two times a week to induce liver damage until the treatment ended. Results: Serum biochemical analysis indicated that GE ameliorated the elevation of aspartate aminotransferase and alanine aminotransferase and albumin decline in $CCl_4$-treated rats. Moreover, $CCl_4$-induced accumulation of hepatic total cholesterol and triglyceride was inhibited. The hepatoprotective effects of GE involved enhancing the hepatic antioxidant defense system including glutathione, glutathione peroxidase, glutathione reductase, glutathione S-transferase, superoxide dismutase, and catalase. In addition, histological analysis using hematoxylin and eosin and Masson's trichrome staining showed that GE inhibited $CCl_4$-induced hepatic inflammation and fibrosis. Furthermore, immunohistochemical staining of alpha-smooth muscle actin indicated that $CCl_4$-triggered activation of hepatic stellate cells was reduced. Conclusion: These findings demonstrate that GE improves $CCl_4$-induced liver inflammation and fibrosis by attenuating oxidative stress. Therefore, GE could be a promising hepatoprotective herbal formulation for future development of phytotherapy.