• Journal of Pharmaceutical Investigation
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• v.21 no.2
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• pp.67-71
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• 1991

A simple and sensitive method was developed for the quantification of free and conjugated bile acids in bezoar without prior hydrolysis. $3{\alpha}-Hydroxy$ bile acids are first oxidized to 3-keto bile acids in the reaction catalyzed by $3{\alpha}-hydroxysteroid$ $dehydrogenase(3{\alpha}-HSD)$. During this oxidative reaction, an equimolar quantity of nicotinamide adenine dinucleotide(NAD) is reduced to NADH and subsequently oxidized to NAD with concomitant reduction of nitrotetrazolium blue(NTB) to diformazan by the catalytic action of diaphorase. The diformazan has an absorbance maximum at 540 nm. The intensity of the color produced is directly proportional to bile acids concentration in the bezoar extracts. The optimum conditions for the enzymatic reaction such as effects of reaction time, reaction temperature and pH, and stability were investigated. Calibration plots for the sodium chelate observed to be linear and intra-, inter-assay analytical recovery of bile acids averaged $97.65{\pm}3.4%(S.D.)$. Therefore, it is considered that the quality control of total bile acids from bezoar or bezoar-containing liquid preparation using this simple and sensitive assay system will be acceptable. Also current bezoars and bezoar-containing liauid preparations were examined their total bile acids from this method.

• Restorative Dentistry and Endodontics
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• v.38 no.3
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• pp.167-171
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• 2013

Biomechanical preparation of root canals with accentuated curvature is challenging. New rotatory systems, such as Reciproc, require a shorter period of time to prepare curved canals, and became a viable alternative for endodontic treatment of teeth with root dilaceration. Thus, this study aimed to report a clinical case of endodontic therapy of root with accentuated dilaceration using Reciproc single-file system. Mandibular right second molar was diagnosed as asymptomatic irreversible pulpitis. Pulp chamber access was performed, and glide path was created with #10 K-file (Dentsply Maillefer) and PathFile #13, #16 and #19 (Dentsply Maillefer) up to the temporary working length. The working length measured corresponded to 20 mm in the mesio-buccal and mesio-lingual canals, and 22 mm in the distal canal. The R25 file (VDW GmbH) was used in all the canals for instrumentation and final preparation, followed by filling with Reciproc gutta-percha cones (VDW GmbH) and AH Plus sealer (Dentsply Maillefer), using thermal compaction technique. The case has been receiving follow-up for 6 mon and no painful symptomatology or periapical lesions have been found. Despite the difficulties, the treatment could be performed in a shorter period of time than the conventional methods.

• Journal of the Korean Ceramic Society
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• v.45 no.9
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• pp.518-523
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• 2008

The mechanical properties of silicon carbide deposited by chemical vapor deposition process onto a graphite substrate are studied using nanoindentation techniques. The silicon carbide coating was fabricated in a chemical vapor deposition process with different microstructures and thicknesses. A nanoindentation technique is preferred because it provides a reliable means to measure the mechanical properties with continuous load-displacement recording. Thus, a detailed nanoindentation study of silicon carbide coatings on graphite structures was conducted using a specialized specimen preparation technique. The mechanical properties of the modulus, hardness and toughness were characterized. Silicon carbide deposited at $1300^{\circ}C$ has the following values: E=316 GPa, H=29 GPa, and $K_c$=9.8 MPa $m^{1/2}$; additionally, silicon carbide deposited at $1350^{\circ}C$ shows E=283 GPa, H=23 GPa, and $K_c$=6.1 MPa $m^{1/2}$. The mechanical properties of two grades of SiC coating with different microstructures and thicknesses are discussed.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2008.03a
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• pp.178-178
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• 2008

In order to improve static stability and healing of reattached labrum, we combined the advantages of suture bridge and transosseous technique. Using the conventional 3 portal for anterior instability, check stability of bony Bankart and preparation of glenoid bed in 3 way including removal, reshaping or mobilization of bony fragment. Two anchors were inserted to the superior and inferior portion and medial edge of bony Bankart lesion. It usually corresponded to the area of IGHL. Medial mattress sutures were applied around IGHL complex to get enough depth of glenoid coverage using suture hook. Make 3.5mm pushlock anchor hole to the articular edge of glenoid cartilage. Proximal suture bridge was applied at first and then distal suture bridge was inserted to mobilize the labrum in proximal direction. These construction can provide more stable labral repair with wide contact and compression in case of deficient bony stability. It not only avoids technical disadvantage of point contact with anchor fixation, but also decreasing gap formation through cross compression of labrum that couldn't gain even with the transosseous fixation which affords linear compression effect. Additional bony stability could be gained if the the bony fragment was mobilized to the glenoid margin with potential healing bed or reshaped for the good contact with reattached labrum.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.3
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• pp.153-157
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• 2007

Mockeoseuk(China fossil) contains the various kinds of minerals and radiates far infrared light. In order to apply mockeoseuk to the cosmetic formulation, hybridization technique was adapted and modified by selecting a spherical silicone powder as substrate. The resultant composite improved the physical properties such as skin feeling and apparent color and still sustained the efficacy of mockeoseuk. In a clinical test, the cosmetic formulation with 10 wt% mockeoseuk composite raised the temperature of facial skin through enhancement of skin blood flow.

• 한국컴퓨터산업교육학회:학술대회논문집
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• 2003.11a
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• pp.105-110
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• 2003

Number of information users of industry, school and research institute with arrival of knowledge information society are in trend that increase gradually the 21th century. Manufacture user number of database been circulating is examined to fourteen million, six hundred and twenty-four thousand people in internal until end of 2002 if follow to Korea data base promotion center, this shows increase more than yearly mean $70\%$ every year by increasing provision $70.3\%$ past years. That collect rapidly and analyze connection importance information of scientific technique field in this hard fact and offer efficiently timely to investigator processing can say as indispensable indispensability a element in country science technique elevation. Wish to illuminate Specialized Information Center of scientific technique field's role and significance in this hard fact in this research, and examine the role and significance. Together, wish to present way for research direction and Specialized Information Center development by introducing phase thesis and synthetic middle, effort of Korea Institute of Science and Technology Information(KISTI) for special skill development way preparation and study finding for each Specialized Information Center.

• Journal of the Korean Ceramic Society
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• v.56 no.5
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• pp.443-452
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• 2019

In this study, TiO₂-polyvinyl alcohol (PVA) composite granules were prepared via spray drying technique. To investigate the effects of solid content and binder/powder ratio in the slurry on the granulation behavior of TiO₂ powders, the feed compositions were designed to vary over a wide range. The morphology, actual densities, and average granule size and size distribution of the TiO₂-PVA composite granules were characterized by using scanning electron microscopy technique, a gas pycnometer, and an image analyzing program (Image-J), respectively. The results indicate that solid content and the amount of PVA in the feedstock slurry are the dominant factors determining the granule morphology, size, and size distribution of TiO₂-PVA composite. Moreover, it was observed that increasing the solid content and the amount of PVA in the slurry improved the granulation process and reduced the granule defects. For the preparation of spherical TiO₂-PVA composite granules with the minimum amount of non-granulated powders, the optimized composition of the feedstock slurry was found to be 35 wt.% solid and 3 wt.% PVA.

• Restorative Dentistry and Endodontics
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• v.45 no.3
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• pp.27.1-27.9
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• 2020

Apical surgery for a mandibular molar is still challenging for many reasons. This report describes the applications of computer-guided cortical 'bone-window technique' using piezoelectric saws that prevented any nerve damage in performing endodontic microsurgery of a mandibular molar. A 49-year-old woman presented with gumboil on tooth #36 (previously endodontically treated tooth) and was diagnosed with chronic apical abscess. Periapical lesions were confirmed using cone-beam computed tomography (CBCT). Endodontic microsurgery for the mesial and distal roots of tooth #36 was planned. Following the transfer of data of the CBCT images and the scanned cast to an implant surgical planning program, data from both devices were merged. A surgical stent was designed, on the superimposed three-dimensional model, to guide the preparation of a cortical window on the buccal side of tooth #36. Endodontic microsurgery was performed with a printed surgical template. Minimal osteotomy was required and preservation of the buccal cortical plate rendered this endodontic surgery less traumatic. No postoperative complications such as mental nerve damage were reported. Window technique guided by a computer-aided design/computer-aided manufacture based surgical template can be considerably useful in endodontic microsurgery in complicated cases.

• Membrane and Water Treatment
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• v.13 no.4
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• pp.201-208
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• 2022

Emulsion Liquid Membrane (ELM) is a prominent technique for the separation of heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of the components (Surfactant and Carrier) of ELM is a very significant step for its preparation. In the ELM technique, the primary water- in-oil (W/O) emulsion is emulsified in water to produce water-in-oil-in-water (W/O/W) emulsion. The water in oil emulsion was prepared by mixing the membrane phase and internal phase. To prepare the membrane phase, the extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2- ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II). Emulsion Liquid Membrane (ELM) is a well-known technique for separating heavy metal ions from wastewater due to the fast extraction and is a single-stage operation of stripping-extraction. The selection of ELM components (Surfactant and Carrier) is a very significant step in its preparation. In the ELM technique, the primary water-in-oil (W/O) emulsion is emulsified to produce water-in-oil-in-water (W/O/W) emulsion. The water in the oil emulsion was prepared by mixing the membrane and internal phases. The extractant D2EHPA (di-2-ethylhexylphosphoric acid) was used as a mobile carrier, Span-80 as a surfactant, and Paraffin as a diluent. Moreover, the internal (receiving) phase was prepared by dissolving sulphuric acid in water. Di-(2-ethylhexyl) phosphoric acid such as surfactant concentration, carrier concentration, sulphuric acid concentration in the receiving (internal) phase, agitation time (emulsion phase and feed phase), the volume ratio of the membrane phase to the receiving phase, the volume ratio of the external feed phase to the primary water-in-oil emulsion and pH of feed were studied on the percentage extraction of metal ions at 20℃. The results show that it is possible to remove 78% for As(V), 98% for Cd(II), and 99% for Pb(II).

• Journal of the Korean Chemical Society
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• v.28 no.1
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• pp.41-46
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• 1984

To preconcentrate trace elements, microgram amounts of 5 heavy metals (Cu, Co, Ni, Zn and Cd) were precipitated with 8-hydroxyquinoline (oxine) and metal oxinates were extracted with stearic acid. And then each of the molten stearic acid extract with stearic acid. And then each of the molten stearic acid extract was poured into a glass ring and cooled for specimen preparation. The obtained specimens were analyzed by X-ray fluorescene spectrometry. And then conditions of precipitation formation and extraction, reproducibility, sensitivity and detection limit were observed. The relative standard deviation of specimen preparation was 1.0~5.7% and the detection limit was 5~$50{\mu}g$/100ml. The proposed preconcentration procedure exhibited a considerable inhancement and simplicity in preparing specimens.