Improvement of Thermoplastic Forming Ability of Ti–Zr–Ni–Cu Metallic Glass by Addition of Sn

Yeong‑Seong Kim,Woo‑Chul Kim,Won‑Tae Kim,Do‑Hyang Kim 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

Ti–Zr–Ni–Cu metallic glass attracts an attention as a precursor of superelastic alloy that can be deformed into nm scalecomplex shapes. However, since the thermal stability of Ti–Zr–Ni–Cu metallic glass in the supercooled liquid region is quitelow, application of thermoplastic forming is limited. Therefore, in the present study, the effect of Sn addition on thermoplasticforming ability of Ti–Zr–Ni–Cu metallic glass has been investigated. Sn containing (Ti35Zr15Ni35Cu15)99Sn1 metallic glassexhibits longer incubation time before onset of crystallization than Ti35Zr15Ni35Cu15metallic glass, resulting in significantimprovement of thermoplastic forming ability. The crystallization behavior changes from three-dimensional growth of saturatednuclei to three-dimensional growth with constant nucleation rate with the addition of Sn. The overall activation energyfor crystallization of (Ti35Zr15Ni35Cu15)99Sn1 metallic glass is higher than that of Ti35Zr15Ni35Cu15metallic glass, indicatingthat the thermal stability of metallic glass is improved by addition of Sn. Because nuclei are continuously generated duringthe crystallization in (Ti35Zr15Ni35Cu15)99Sn1, the average grain size is much smaller than that in Ti35Zr15Ni35Cu15.

하악 소구치에 발생한 치외치의 치근단유도술

이지민,최영철,김광철,최성철 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.2

치외치(Dens Evaginatus)란 교합면에 법랑질이 원추형으로 돌출되어 결절을 형성한 치아로 치아발육중 법랑기의 내측법랑상피가 외부로 과증식되거나 치수 간엽조직이 국소적으로 과증식되어 나타난다. 결절은 교합력이나 저작에 의해 파절 또는 마모되기 쉬우며 따라서 이로 인하여 치수노출에 의한 감염이 야기될 수 있다. 치외치는 예방목적으로 결절을 주기적으로 조금씩 갈아주어 2차 상아질을 유도하거나 전색제등으로 결절주위를 보강하여 자연마모를 유도할 수 있다. 반면 이미 증상을 보인 치아에 대해서는 근관치료를 시행하거나, 미완성치근인 경우 치근단유도술(Apexogenesis)이나 치근단형성술(Apexification)을 시행한다. 치근단유도술이란 생활력을 가진 미성숙 영구치의 손상, 또는 치아우식에 의한 치수노출 시 치수절단술을 시행하여 치수의 생활력을 유지시켜 정상적인 치근으로 발육하도록 유도하는 술식을 말한다. 주로 수산화칼슘을 이용한 통상의 치수절단술이 이용되고 이후 계속적인 치근형성 확인을 위해 주기적 방사선검사가 요구된다. 본 증례는 하악 좌측 제2소구치 부위의 동통을 주소로 내원한 환자에 대한 것으로, 임상검사결과 양측 소구치 부위에 치외치를 확인하게 되었다. 이에 수산화칼슘을 통한 치근단유도술을 시도하였고, 3년간 주기적 내원을 통해 치료한 결과 치근의 근심면의 비정형적 발달을 보였다. 현재 이 치아는 임상증상과 방사선 사진을 통해 확인한 결과 특이한 염증소견 없는 예후를 보이고 있기에 보고하는 바이다. Dens evaginatus is a dental anomaly most commonly seen in premolar teeth in which a tubercle or protuberance projects from either the center of the occlusal surface or the buccal triangular ridge. These tubercles are easily fractured from mastication as the tooth erupts and frequently leads to pulp necrosis as a common complication. To prevent these sequelae, prophylactic treatment soon after the tooth starts erupting is essential. These preventive treatments include, selective grinding and protection of the tubercle by pit and fissure sealant. When the tooth does shows signs of pulp necrosis and apical periodontitis, endodontic procedures are needed. Apexification and apexogenesis are usually the treatment of choice for the affected teeth which have immature apices. Apexogenesis is a vital pulp therapy procedure performed to encourage continued physiological development and formation of the root end. It involves removal of the inflamed pulp and the placement of calcium hydroxide on the remaining healthy pulp tissue. This case report describes an atypical apexogenesis of a mandibular premolar which showed to be a dens evaginatus. The tooth which was treated with calcium hydroxide shows good results and is planned for permanent root canal filling.

전치부의 경미한 공간부조화 개선을 위한 가철성 장치의 적용 예

곽아람,최영철,박재홍,최성철,김광철 大韓小兒齒科學會 2007 大韓小兒齒科學會誌 Vol.34 No.4

골격성 부조화가 없는 I급 부정교합은 치아-악궁 간의 크기 차이에 의한 총생(crowding)이나 공극(spacing)이 주된 문제점이다. 이와 같은 경미한 공간 부조화를 개선시키고자 할 때,치열의 종류,치아-악궁크기 부조화의 양,환자의 협조도,또는 환자의 요구 등에 따라 치료 방법은 다양할 수 있다. 본 증례보고에서는 I급 구치부 관계를 지니면서 전치부의 치아-악궁크기 부조화의 양이 크지 않은 영구치열에서 상하 악 전치부의 경미한 총생이나 공극이 관찰되는 경우에 사용할 수 있는 clear aligner와 spring aligner 장치의 이용에 관하여 보고하고자 한다. 이와 같은 장치들의 임상 적용에는 몇 가지 제한적인 조건이 있기는 하지만,잘 선택된 증례에서는 매우 유용하며 편리하게 이용될 수 있다. 특히 총생이 존재하는 경우에는 이를 해소시킬 공간이 치열 내에서 확보되어야 하므로,확실한 분석과 진단으로 치아 인접면 삭제의 양을 정확히 결정하여 각 치아들의 근심면과 원심면에서의 삭제의 양이 균등히 이루어질 수 있도록 하는 것이 바람직하다. 또한 치간에 공극이 존재하는 경우에는 배열 후 치열궁 둘레의 감소와 함께 상하악 전치부 간의 over-jet 문제가 생길 수 있어 대합치열과의 교합관계에 신중을 기하여야 한다. Class I malocclusion without skeletal problem results from tooth size/arch-size discrepancies, either evidenced by crowding, or spacing problems. Treatment method can be chosen according to dentition, the amount of arch discrepancy, patient compliance, or patient demands. We report of clear aligner and spring aligner that can be applicated in cases of permanent dentition with minimal arch discrepancy in anterior segment. There are some limits of application, but these are very useful appliances in the selective case. When crowding exists, definitive analysis and diagnosis should be made before starting treatment because certain amount of space must be obtained somewhere in the dentition to resolve the crowding. Therefore, appliance should be applied when lacking space is small. Also, in cases with spacing arch circumference is reduced after alignment so no problem in intermaxilla occlusal relationship must be confirmed. In case with crowding, judicious removal of interproximal enamel is indicated.

수종의 불소방출 수복재의 탈회억제 효과 및 불소침투에 관한 연구

김송이,최성철,최영철,김광철,박재홍 大韓小兒齒科學會 2010 大韓小兒齒科學會誌 Vol.37 No.3

자이오머(Giomer)는 레진강화형글라스아이오노머에 견줄 만큼 불소방출량이 많다고 하나, 우식예방 효과에 관한 연구들이 많지 않아 임상적용에 대한 근거가 부족한 실정이다. 본 연구는 자이오머(BF 군)를 포함하여 레진강화형글라스아이오노머(FF 군), 콤포머(DA 군)와 대조군인 콤포짓(FZ 군)의 우식억제 효과와 주변 치질로의 불소침투 양상을 비교하기 위하여, 공초점레이저주사현미경과 전자탐침미세분석기를 이용하여 각 수복재의 우식예방 효과를 비교하였으며, 다음과 같은 결과를 얻었다. 1. 수복물 주위 이차 인공우식에서 법랑질 외측병변의 깊이는 FZ 군에서 가장 깊었으며, BF 군이 가장 작게 나타났다(p<0.05). 2. 수복물과 법랑질 계면에 나타난 탈회억제층의 두께를 관찰한 결과 FZ 군이 가장 작게 나타났으며, FF, DA, BF 간에는 유의성 있는 차이를 보이지 않았다(p<0.05). 3. 법랑질에 침투된 불소농도는 BF, FF, DA의 순으로 높게 나타났다. 4. 상아질에 침투된 불소농도는 DA, BF, FF의 순으로 높게 나타났으며, 이는 상아질-수복물의 접착 계면에 영향 받는 것으로 보인다. The purpose of this study was to evaluate the effect of light cured fluoride-releasing materials on the inhibition of demineralization. In addition, the pattern of fluoride uptake of adjacent tooth structure was analyzed with EPMA. Eighty intact premolars were restored with Filtek Z250(control group, composite), Fuji Filling LC(RMGI), Dyract AP (compomer) and Beautifil II(giomer). Restored teeth were stored in distilled water for 30 days. Thensixty teeth(n=15) were exposed to demineralizing solution(pH 4.3). Demineralized teeth were bisected and polished. The specimens were observed with confocal laser scanning microscope. The depth of outer lesion and the thickness of inhibition zone were measured. Remained twenty teeth(n=5) were bisected for fluoride uptake analysis. The fluoride analysis were taken at enamel-restoration interface and dentin-restoration interface by electron probe micro-analyzer. The results are as follows: 1. The depth of outer lesion of Fuji Filling LC, Dyract AP, Beautifil II was shallower than that of Filtek Z250 at the margin of restoration(p<0.05). 2. The thickness of caries inhibition zone of Fuji Filling LC, Dyract AP, Beautifil II was greater than that of Filtek Z250 at the margin of restoration(p<0.05). 3. Fuji Filling LC, Dyract AP, Beautifil II groups showed the greater fluoride uptake into enamel and dentine around restoration than Filtek Z250 group. 4. In dentin the difference of fluoride concentration were greater than in enamel, and Dyract AP showed the greatest fluoride concentration in dentin.

구순구개열 환아에서의 치조골이식

조해성,박재홍,김광철,최성철,이긍호,최영철 대한소아치과학회 2007 大韓小兒齒科學會誌 Vol.34 No.1

치조파열 및 구개열과 같은 선천성 기형은 이환된 환자에게 기능적, 심미적으로 많은 문제점을 야기하므로 정상으로 회복시켜 주는 것은 중요한 문제이다. 장기간 방치될 경우 영양장애, 구강위생 불량, 호흡기 간염, 언어 장애, 악안면 변형, 그리고 정신적인 문제 등이 복합적으로 발생할 수 있다. 따라서 구순구개열 환자의 치료는 여러 전문 치료 분야의 복합적인 접근이 필요하다. 골이식은 구순구개열 환자에 있어 중요한 치과치료 단계이다. 치아의 맹출과 치열의 안정화를 위해 치열궁은 골격손이 없이 완전해져야 한다. 또한 치열궁의 파열이 있는 부위로는 정상적인 교정적 치아이동이 곤란하다. 따라서 구순구개열 환자에 있어 골이식은 광범위하게 적용되고 있는 외과적 술식이다. 치조골을 이식함으로써 치조열은 안정화되고, 견치 또는 절치가 이식부위로 이동할 수 있게 된다. 그리고 골 이식 후, 교정을 통해 치조열 부위의 공간을 폐쇄함으로써 보철 치료 없이 치열을 재형성할 수 있다. 골이식술에는 다양한 이식재료가 사용되었다. 자가골을 이식할 경우 장골이 가장 선호되며, 그 밖에 경골, 늑골, 두개골, 하악골을 이용하기도 한다. 그리고 골이식은 골이식 시기에 따라 일차골이식, 조기 이차골이식, 이차골이식, 만기 이차골이식으로 구분할 수 있다. 이차골이식은 혼합치열기 말경에 시행되는 것을 말하며 가장 좋은 것으로 받아들여지고 있다. 영구 견치가 맹출되기 전에 이차골이식을 시행하면 인접치아의 맹출과 보존에 도움이 된다. 본 증례에서는 치조구개파열 환자의 장골에서 골을 채취하여 골 이식을 시행한 후, 골이 채워진 이식 부위에 인접 치아가 성공적으로 이동하거나 치축이 개선되고 교정치료를 통해 치열궁 배열의 만족스러운 결과를 얻었기에 이를 보고하는 바이다 Cleft lip and palate are congenital craniofacial malformation. Reconstruction of dental arch in patient with alveolo-palatal clefts is very important, because they have many problems in functions and esthetics. Malnutrition, poor oral hygiene, respiratory infections, speech malfunctions, maxillofacial deformity, and psychological problems may be occured without proper treatment during the long period of management of the cleft lip and palate. So the treatment should be managed with a multidisciplinary approach. Bone grafting is a consequential step in the dental rehabilitation of the cleft lip and palate patient. A complete alveolar arch should be achieved of the teeth to erupt in and to form a stable dentition. And the presence of the cleft complicate the orthodontic treatment. Therefore bone grafting in patients with cleft lip and palate is a widely adopted surgical procedure. Grafted bone stabilizes the alveolar process and allows the canine or incisor to move into the graft site. After the bone grafting, orthodontic closure of the maxillary arch has become a common practice for achieving dental reconstruction without any prosthodontic treatment. Various grafting materials have been used in alveolar clefts. Iliac bone is most widely fovoured, but tibia, rib, cranial bone, mandible have also been used. And according to its time of occurrence, the bone graft may be divided into primary, early secondary, secondary, late secondary. Bone grafting is called secondary when performed later, at the end of the mixed dentition. It is the most accepted procedure and has become part of treatment of protocol. A secondary bone graft is performed preferably before the eruption of the permanent canine in order to provide adequate periodontal support for the eruption and preservation of the teeth adjacent to the cleft. In this report, we report here on a patient with unilateral cleft lip and palate, who underwent iliac bone graft. The cleft was fully obliterated by grafted bone in the region of the alveolar process. The presence of bone permitted physiologic tooth movement and the orthodontic movement of adjacent tooth into the former cleft area. Satisfactory arch alignment could be achieved in by subsequent orthodontic treatment.

콩에서 발생하는 강낭콩일반모자이크바이러스(BCMV)와 땅콩위축바이러스(PSV)의 저항성 평가

이영훈, 윤영남, 강범규, 김현영, 최만수, 구성철, 김현태, 윤홍태, 이수헌, 백인열 忠北大學校 農業科學硏究所 2014 農業科學硏究 Vol.30 No.2

It has been reported several viral diseases in soybean. The occurrence of Bean common mosaic virus and Peanut stunt virus are able to induce severe problem because the main breeding target for viral disease was focused on Soybean mosaic virus. BCMV is a spcies of the genus Potyvirus of the family Potyviridae. BCMV reduces yield by as much as 80% and also adversely affects seed quality in common bean. BCMV has a worldwide distribution because of its high rates 35% of transmission via seeds produced by plants systemically infected prior to bloom. PSV is a species of the genus Cucumovirus of the family Bromoviridae. PSV has been reported to be economically damaging on beans worldwide. Although the virus is reportedly seed transmissible at very low rates, infected plants rarely produce pods with normal viable seeds. The most satisfactory management method of viral diseases such as BCMV and PSV is the use of resistant cultivars and healthy seed. For the overcome of genetic resistance by new virus such as BCMV and PSV, virus diseases monitoring and researches need to study deeply and continually. In this study, we conducted the resistance screen on BCMV and PSV for selection of resistance cultivars. We inoculated on 128 cultivars with PSV and BCMV respectively. These cultivars were classified through pathogenic response such as resistance, necrosis and susceptibility. In addition, 99 and 66 resistant cultivars were confirmed against PSV and BCMV respectively.

개나리 형질전환에 관한 연구

추갑철,김우룡,이용섭,권영한 진주산업대학교 1999 산업과학기술연구소보 Vol.- No.6

본 연구는 우리 나라 전역에 널리 식재 되고 있는 개나리를 이용하여 목본식물의 형질전환방법을 확립하고 형질전환용 시료의 다양화를 위하여 실시하였다. 기내에서 식물체를 증식하기 위하여 배지의 조성 및 식물생장조절제의 농도와 조합을 조사하였다. 줄기의 증식에 미치는 싸이토키닌의 종류별 효과는 BAP, kinetin과 zeatin을 4가지 농도별로 처리하였고, 절편배양 후 7일부터 기부가 부풀어오르고 액아로 부터 줄기의 생장을 육안으로 관찰할 수 있었다. 배양초기의 줄기생장은 생장호르몬의 종류나 농도에 따라 큰 차이를 보이지 않았다. 세 가지의 싸이토키닌 중 kinetin의 첨가는 BAP나 zeatin의 처리보다 줄기유도는 저조하나 부정근의 형성은 뚜렷하게 촉진되었다. BAP는 0.5㎎/ ℓ농도 이상에서 줄기유도에 다소양호하였다. 캘러스를 유도는 MS배지에 0.1㎎/l BAP^+ 0.5, 1.0㎎/l 2,4-D등에서 갈변되지 않고 성장이 왕성한 킬러스를 얻을 수 있었다. 식물형질전환을 위하여 식물형질전환 벡터 pBI12l을 Agrobacterium tumefaciens LBA 4404에 삽입하여 함께 공조배양 하였다. 공조배양 후 CIM배지에 배양한 후 SIM에 이식하여 부정아를 유도하였다. 유도된 캘러스로부터 식물체를 유도하여 증식하였다. 증식된 식물체의 형질전환을 검정하기 위하여 NPT11 ELISA 검정을 실시, 대조구와 비교하여 형질 전환체에서 보다 높은 측정치를 얻을 수 있었다. Transformation system of Forsythia koreana was developed. For shoot formation various cytokinins such as BAP, kinetin and zeatin were tested. Among them, BAP was the most suitable cytokines and it`s optimal concentration was found to be 0.5㎎/ℓ. As for the test finding the callus resistance on medium supplemented with antibiotic, kanamycin, the optimal concentration was 20㎎/ℓ kanamycin. After coculture with Agrobacterium tumefaciens LBA 4404, explants were positioned on CIM(callus inducing medium) and induced callus. Several weeks later, transgenic callus were tested NPTⅡ to confirm transformation and the transgenic callus had higher values than controls. This results seem that Forsythia koreana is a useful plant to develop transformation system in woody plants.

지방산, 지방 알코올 및 프로필렌글리콜이 클렌부테롤의 경피투과에 미치는 영향

이영대,권기철,정시영,이종달,용철순 영남대학교 약품개발연구소 2000 영남대학교 약품개발연구소 연구업적집 Vol.10 No.-

Clenbuterol, a selective β_(2)-adrenergic receptor stimulant, has been introduced as a potent bronchodilator for patients with bronchial asthma, chronic bronchitis and pulmonary emphysema. For the purpose of developing a transdermal preparation for clenbuterol, we attempted to select an optimal solvent system and permeation enhancer among fatty acids and fatty alcohols which are known to accelerate the penetration of various drugs in permeation experiments using hairless mouse skin and Franz diffusion cell. Apparent partition coefficient of clenbuterol was increased as pH of buffer solution was increased and solubility of clenbuterol was increased as the percent of propylene glycol(PG) in buffer solution(pH10) was increased. Permeability of clenbuterol from different buffer(pH 10)/PG solvent mixtures was decreased as the percent of PG in pH 10 buffer solution was increased and among the various enhancers studied, lauryl alcohol was found to be the most effective enhancer, increasing the permeability of clenbuterol approximately 76-fold compared with control. Lauryl alcobol(0-2%) enhanced the permeability of clenbuterol concentration-dependently. In this study, the optimal solvent system for the penetration of clenbuterol was found to be 50/50 buffer(pH 10)/PG solvent mixture containing 2% lauryl alcohol.

황 첨착 활성탄에 의한 구리제거

김영환,박정훈,김정섭,유현철,이봉섭,곽명화,우성훈,박승조 東亞大學校 環境問題硏究所 2005 硏究報告 Vol.27 No.1

This study was carried out to remove copper ion in case of activated carbon impregnated sulphur(ACS) dose and different pH using activated carbon impregnated sulphur that prepared from activated carbon at sulphur dioxide atmosphere. Removal copper ion concentration was increased as increasing the ACS dose when copper ion concentration was 10 mg/L. Optimum dose of ACS 13.3 g ACS/L and maximum removal efficiency was 93%. The results obtained from adsorption experiment in the condition of ACS optimum dose when the pH was 3, 4, 5 respectively was pH 5 was excellent.

완전탈구된 치아의 재식에 관한 치험례

최영철,권오연,김광철,이긍호 大韓小兒齒科學會 1993 大韓小兒齒科學會誌 Vol.20 No.2

Exarticulation includes all cases in which the tooth has been totally displaced out of its socket. The main etilogies in the permanent dentition are direct blows and traffic accident, while in the primary dentition are fall-downs. The prognosis of tooth which has been recieved endodontic treatment after replantation is better than received endodontic treatment before replantation. Ca(OH)₂as a initial canal filling material diminishes undesirable replacement root resorption, so in the cases of compelted and uncompleted root formation, the pulp is extirpated and then a Ca(OH)₂dressing is placed until optimal stage for final canal filling with gutta percha cones. Storage media and storage period of avulsed tooth is very important things for prognosis after replantation. A strong relationship has been found between dry storage or storage in non physiologic media (c.g tapwater) and root resorption. Physiologic saline and/or fresh milk is one of the best storage media.