• 분석과학
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• 제8권4호
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• pp.535-538
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• 1995

This study employs the variety of mixtures of XAD resin and active carbons as concentration base for solid phase extraction (SPE) which has been widely used to preconcentrate and purify phenol and chlorophenols in determination of environmental water samples. In this study, we employed variety of mixtures of copolymer based XAD-4 resin with active carbons. This cartridges shows advantages of both materials, such as better affinity to phenol by active carbon and better mechanical stabilities from XAD resin. The better enrichment factor, pretreatment time, recoveries and limit of detection (LOD) were achieved by the attempts to pack precolumns with both meterials for preconcentration.

• Journal of Pharmaceutical Investigation
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• 제8권2호
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• pp.1-10
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• 1978

During the course of studies on the production of glutathione from yeast, process development and optimization was carried out. The optimal pH for the extraction of glutathione was found to be 2.5 to 4.0 and the maximum yield for glutathione was obtained when the extraction temperature was 25 to $45^{\circ}C$. The cuprous salt of glutathione was recovered maximally at the range of 2 to 4g of cuprous oxide per 10 Kg of compressed yeast. Further purification was needed for the removal of impurities from glutathione. Cation exchange resin, anion exchange resin and Sephadex G-25 were employed for this purpose. 13 to 15 g of glutathione was obtained from 10 Kg of compressed yeast and the purity was above 99.3%.

• Elastomers and Composites
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• 제55권4호
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• pp.289-299
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• 2020

Highly aromatic (HA) oils are common processing aids used in tire tread compounds. However, they often bleed and evaporate from the vulcanizates during tire use. Thus, the mechanical and dynamical properties of the tire decrease. To overcome this problem, we investigated nonfunctionalized liquid butadiene rubber (LBR-305, Kuraray) and center-functionalized liquid butadiene rubber (C-LqBR), polymerized by anionic polymerization. In addition to the liquid butadiene rubbers, p-tert-octylphenol (P-Resin) and C5 hydrocarbon (H-Resin) tackifier resins, which can induce entanglement of rubber compounds, were researched as a processing aid to solve the bleeding problem. Liquid butadiene rubbers have significantly reduced extraction loss by crosslinking with the main rubber chain. They have also increased the abrasion resistance and showed similar or better mechanical and dynamical properties against HA oils. However, resin compounds did not show differences in extraction loss compared to HA oil compounds; instead, they showed increased wet traction.

• Journal of Radiation Protection and Research
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• 제26권1호
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• pp.1-6
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• 2001

방사성 동위원소에 오염된 토양시료에 대하여 정확하고 신속한 U 등위원소 분석법을 개발하였고 IAEA 표준시료에 적용하여 분석법의 타당성을 검증하였다. TBP 용매추출법의 단점을 보완하기 위해서 토양시료를 질산 및 불산을 사용하여 메트릭스 성분으로부터 우라늄을 완벽하게 추출하였고 이온교환수지와 TRU Spec 수지를 이용하여 우라늄 등위원소를 악티나이드 원소로부터 순수분리하였다. 크로마토 그래피 추출법을 사용하여 토양시료에서 우라늄 등위원소 화학수율은 TBP 용매추출법의 경우보다 10% 정도 증가하였다. 크로마토 그래피 추출법을 사용한 IAEA 토양시료에 분석결과는 IAEA에서 보고된 수치와 일치하였다.

• 한국임상수의학회지
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• 제36권2호
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• pp.106-108
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• 2019

This clinical report describes hemisection and endodontic treatment of first molar tooth and mandible fracture repair in a dog. A 10 years old spayed female shih-tzu was diagnosed as left mandibular fracture by oral examination and dental radiography. First, partial odontectomy of mesial root of mandibular first molar placed in fracture line was performed, and then endodontic treatment of distal root and bone graft in extraction site was performed. Thereafter the fracture region was fixed with interdental wiring and acryl resin splint. Mandibular fracture site was healed without any complications, observed for 19 weeks follow-up period. Upon this result, this case is proving that fractured mandible can be treated successfully with hemisection followed by bone graft, interdental wiring and acryl resin splint to preserve the remaining tooth for mastication rather than tooth extraction.

• 방사성폐기물학회지
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• 제13권2호
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• pp.123-130
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• 2015

순수 베타 핵종인 ⁹⁰Sr 분석은 화학적 거동이 유사한 알칼리 토금속(Ca, Ba, Ra)등 방해 원소를 제거할 분리 공정이 필요하다. 본 연구는 Sr을 추출/정제하기 위해 추출크로마토그래피법을 이용한 최적의 절차를 마련하는 것을 목적으로 한다. Sr resin 1.5 mL BV(Bed Volume)의 최대 Sr 흡착량은 6 mg이었다. 유량 1 mL min^-1과 Ca 200 mg 이하에서는 Sr resin 1.5 mL(BV)의 Sr 회수는 정량적이었으나, 유량을 5 mL min^-1으로 중가 시키면 Sr 회수율이 감소하였다. 같은 양(BV)의 Sr resin을 사용할 경우, 컬럼의 단면적이 작을수록 Sr resin의 분리능이 향상되었다.

• 대한장애인치과학회지
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• 제8권2호
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• pp.134-138
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• 2012

In treatment of dentigerous cyst, complete enucleation, histopathologic examination and postoperative care are important to prevent the potential complications (mural ameloblastoma, squamous cell carcinoma). On the other hand, a maxillary impacted supernumerary anterior tooth are removed surgically, owing to the possibility of the cyst formation in future. After the cyst enucleation and extraction of the involved tooth, the wound area sutured and removable resin plate is then applied. In this operation, the postoperative bleeding and infection is likely to occur owing to postoperative accumulation of hematoma & seroma, psychologic stress and other contaminated factor. So, the authors established the immediate rubber & iodoform gauze drainage into the sutured wound of cyst enucleation & tooth extraction for the prevention of postoperative bleeding and infection. The removable resin splint are not used because of the poor cooperation and economic factor. The results were more favorable without the postoperative bleeding & wound infection in a cerebral palsy patient.

• 대한치과의사협회지
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• 제55권12호
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• pp.850-860
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• 2017

Orthodontic treatment with premolar extraction is usually performed to correct bialveolar protrusion. These methods require the use of stiff rectangular working archwire which requires lengthy alignment and leveling before insertion. In this case report, interproximal reproximation was performed instead of extraction. To establish clearance between the archwire and resin domes fixing the archwire, an archwire was inserted into a water-soluble tube before fabricating resin domes. This tube is solved away by the saliva. During fabrication of resin domes, the archwire was deflected intentionally reflecting the displacement of teeth from their ideal position. This can be called as deflection-based bonding (DBB) technique. DBB is different from conventional method of positioning the brackets on its ideal position and then inserting an archwire to align the brackets. Because the orthodontic force of the archwire comes from its deflection from passive configuration, deflecting an archwire as needed can move the teeth more predictably than just bonding brackets on its ideal position. Also, areas with good alignment before orthodontic treatment can be maintained simply by not deflecting the archwire during bonding in these areas. After initial alignment, interproximal reproximation was performed to create 4.8 mm space in the maxillary arch and 4.2 mm space in the mandibular arch. These spaces were closed using orthodontic mini-implant anchorage thus retracting the maxillary incisors 4 mm posteriorly accompanied with 0.7 mm and 0.3 mm distal movement of right and left molars. By using interproximal reproximation and water-soluble tube with DBB, mild bialveolar protrusion was successfully treated without extraction.

• 산업식품공학
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• 제15권3호
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• pp.276-281
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• 2011

탈지미강으로부터 피틴산을 추출 및 정제하기 위한 최적조건을 설정하였다. 탈지미강을 10배수의 0.5% HCl 용액으로 1시간 처리하였을 때 피틴산의 추출효율이 가장 좋았으며 중화제로는 0.5% NaOH 용액이 적합하였다. 피틴산의 정제를 위하여 Diaion HP20 흡착 컬럼을 이용하여 불순물을 제거한 후 여러 가지 이온교환수지를 이용하여 피틴산을 정제하였을 때 Amberlite IRA-416 이온교환수지의 회수율이 가장 높았다. Amberlite IRA-416 이온교환수지를 이용하여 피틴산을 수지에 흡착시킨 다음 0.5% NaOH 용액으로 용출시켰을 경우 89%의 회수율을 나타내었다. 정제된 피틴산의 총단백질 함량은 0.14%(w/w)로 대부분의 단백질이 제거됨을 확인하였다.

• The Journal of Advanced Prosthodontics
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• 제9권6호
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• pp.453-462
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• 2017

PURPOSE. The purpose of this study was to investigate the in vitro cytotoxicity of thermoplastic denture base resins and to identify the possible adverse effects of these resins on oral keratinocytes in response to hot water/ food intake. MATERIALS AND METHODS. Six dental thermoplastic resin materials were evaluated: three polyamide materials (Smile tone, ST; Valplast, VP; and Luciton FRS, LF), two acrylic materials (Acrytone, AT; and Acryshot, AS), and one polypropylene resin material (Unigum, UG). One heat-polymerized acrylic resin (Vertex RS, RS) was chosen for comparison. After obtaining extracts from specimens of the denture resin materials (${\phi}=10$ mm and d=2 mm) under different extraction conditions ($37^{\circ}C$ for 24 hours, $70^{\circ}C$ for 24 hours, and $121^{\circ}C$ for 1 hour), the extracts (50%) or serial dilutions (25%, 12.5%, and 6.25%) in distilled water were co-cultured for 24 hours with immortalized human oral keratinocytes (IHOKs) or mouse fibroblasts (L929s) for the cytotoxicity assay described in ISO 10993. RESULTS. Greater than 70% viability was detected under all test conditions. Significantly lower IHOK and L929 viability was detected in the 50% extract from the VP ($70^{\circ}C$) and AT ($121^{\circ}C$) samples (P<.05), but only L929 showed reduced viability in the 50% and 25% extract from LF ($37^{\circ}C$) (P<.05). CONCLUSION. Extracts obtained from six materials under different extraction conditions ($37^{\circ}C$, $70^{\circ}C$, and $121^{\circ}C$) did not exhibit severe cytotoxicity (less than 70% viability), although their potential risk to oral mucosa at high temperatures should not be ignored.