• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.16.1-16.9
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• 2018

Objectives: Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods: This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results: Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions: Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

• 대한장애인치과학회지
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• 제10권2호
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• pp.84-88
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• 2014

1. 순측접근법은 치수치료를 순측으로 시행한 후 변색된 순측의 치질을 확대하여 삭제하고 레진으로 순면전체를 수복함으로써 치수치료와 동시에 심미성을 회복할 수 있다. 2. 순측으로 치수치료를 시행하므로 시야가 확보에 유리하고 기구조작이 용이해 행동조절이 잘 되지 않는 어린이에게 추천된다.

• 한국산림과학회지
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• 제99권2호
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• pp.226-234
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• 2010

This study was conducted to examine the effects of pruning season on the compartmentalization of pruning wounds in Acer palmatum and Pinus strobus. A total of eighty five field-grown trees for each species were allocated to five different seasons, early- and late-winter, mid-spring, mid- and late-summer, for pruning treatments. Wound closure rate (WCR) of the two species for one year after treatment, area of discolored stem tissue on the medial longitudinal surface and cambial dieback length under the pruning wound of A. palmatum were measured. Changes of total phenols and variations of extractives, holocellulose and lignin at the treated branch unions were examined. In WCR of A. palmatum, late-winter (March, 39.8%) and mid-spring (May, 39.7%) were higher than any other seasons, while early-winter (November, 28.4%) was significantly lower than late-winter and mid-spring. P. strobus showed similar results with A. palmatum. The WCR of early-winter (57.2%) was the lowest significantly among the five seasons, and mid-spring (73.5%) and late-winter (71.4%) showed higher a WCR than other seasons. In the discolored/wound area ratio of A. palmatum, early-winter (73.2%) was the highest by far, and mid- (July) and latesummer (September, 36.7%, respectively) were the lowest among the five seasons. In the length of cambial dieback, two dormant seasons, early- and late-winter were longer than any other seasons. Phenol contents at the treated branch union were changed in line with the seasonal fluctuation of the tree. Total phenols in the below core of the treated union were higher than those of the branch union with living branch, while little differences were seen in the above core. At the branch core of the treated union, phenols of A. palmatum decreased one month after the treatments, but P. strobus maintained similar to or a little higher than those at the controls. The major changes in chemical composition at pruning wounds were extractives and lignin increased by less than 20% in A. palmatum, while extractives in P. strobus remarkably increased by 70%.

• 한국산림과학회지
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• 제99권2호
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• pp.220-225
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• 2010

This study was conducted to examine the effects of wound dressing with thiophanate-methyl paste on the compartmentalization of pruning wounds in Acer palmatum. A total of thirty field-grown trees were used for three different treatments, such as no dressing, dressing once right after pruning cut, and dressing twice, one more dressing treatment one year after initial dressing. Wound closure rate (WCR) and discolored/wound area ratio (D/W ratio) two years after treatment were measured. Variations of extractives, holocellulose and lignin at the treated branch unions were also examined. The WCR of no dressing treatment of 70.9% was significantly lower than those of the two dressing treatments (85.4% and 82.7%, respectively), while the difference between dressing once and twice was not significant. The D/W ratio of no dressing treatment (39.3%) was significantly higher than those of the two dressing treatments (around 30%). Generally, at the branch core of the treated union, contents of extractives and lignin were higher and holocellulose contents were lower than the branch core of the union with living branch. Among the branch core of treated union, no dressing treatment showed a relatively lower holocellulose (63.5%), and relatively higher extractives (2.8%) and lignin (26.6%) than dressing once (66.2%, 1.7%, 26.1%, respectively).

• 식물병연구
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• 제20권4호
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• pp.270-274
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• 2014

본 연구의 목적은 신갈나무에서 참나무시들음병 병원균인 Raffaelea quercus-mongolicae의 지역별 균주와 기타 Raffaelea 속 근연종의 병원성을 평가하는 것이다. 이 연구에서는 신갈나무에 다양한 균주를 접종한 후, 변재부 내 변색정도로 각 균주의 병원성을 판단하였다. 그 결과 변색부의 평균 측면 확산 정도는 국내에서 분리한 Raffaelea quercus-mongolicae 병원균(8.69 cm)이 일본 병원균(7.51 cm)이나 기타 Raffaelea 속 근연종(3.35 cm)의 평균보다 높았고, 국내 지역별 Raffaelea quercusmongolicae 균주간에는 변색부 측면 확산정도가 4.71-14.90 cm로 병원성의 차이를 보였다. 균주간의 변색부 면적 확산정도는 $1.57-8.42cm^2$로 서로 다른 병원성의 차이를 보였으며, 가장 높은 병원성은 강원도에서 분리한 YY와 전라북도에서 분리한 wj43에서 나타났다.

• 한국음향학회지
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• 제39권6호
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• pp.576-584
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• 2020

폴리비닐알코올(polyvinyl alcohol, PVA)젤을 온도가시화용 생체모의매질로 사용하기 위한 기초적인 정보를 얻기 위하여, PVA의 농도를 바꾸어가며 집속초음파에 의한 온도변화 특성을 조사하였다. 기본적인 음향 특성을 조사하기 위하여 PVA농도에 따른 음속, 감쇠계수, 밀도 등이 측정되었고 열역학적 특성인 열전도도, 열용량이 측정되었다. 30 ℃ 이상에서 변색되는 시온필름을 사용하여 집속초음파에 의해 상승되는 초점부근의 온도 변화의 범위를 관찰하였으며 기록된 이미지의 화상처리를 통하여 변색범위의 면적을 도출하였다. PVA의 농도가 2 wt%~16 wt%의 범위에서 증가할수록 젤 내부에서 30 ℃ 이상으로 상승하는 영역은 선형적으로 증가함을 보였고 집속초음파 트랜스 듀서에 인가하는 파워가 증가할수록 변색영역이 증가함을 확인하였다. 이들 결과는 유한요소법을 사용한 시뮬레이션 결과와도 좋은 일치를 보였다.

• Korean Chemical Engineering Research
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• 제58권2호
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• pp.286-292
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• 2020

본 연구에서는 별도의 이미지 분석 장비를 사용하지 않고 정량적으로 알부민의 농도를 측정할 수 있는 회전각도를 이용한 3차원 종이 칩(3D-PADs)를 제시한다. 변색된 구간의 회전각도를 측정하는 간단한 방법으로 검출을 시연하였다. 3D-PADs는 왁스 프린터를 이용한 인쇄와 라미네이팅 과정을 거쳐 빠르게 제작할 수 있다. 3D-PADs는 샘플의 알부민을 검출하기 위하여 citrate buffer와 tetrabromophenol blue를 흡수시켰다. 3D-PAD의 흡수패드에 샘플 용액을 흡수시키면, 샘플 용액은 형성된 유로를 통하여 수직 및 수평 흐름을 통해 분석 구간으로 흐른다. 변색된 구간의 회전각도는 특정한 알부민의 농도를 나타내며, 알부민 측정의 신뢰할 수 있는 값임을 확인할 수 있었다.

• 한국산림과학회지
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• 제98권5호
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• pp.618-629
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• 2009

The objective of this study was to examine the impact of pruning (P treatment) and transplanting (T treatment) of Acer palmatum on cambial growth and compartmentalization of pruning wounds for one year after treatments. Changes of cambial electrical resistance (CER), sizes of pruning wounds, cambial growth of trunks and stems near the wounds, and total phenols at branch unions during the period were examined using a total of 49 trees. After harvesting, areas of discolored wood behind the wounds, relative proportions of extractives, holocellulose and lignin at branch unions were also determined. CER and the cambial growth of trunk at 30 cm above the ground (TGR) were inversely correlated, and differences of CER and TGR among three treatments were significant. TGRs of control, P treatment and P+T treatment after the treatments were 112.2%, 72.4% and 52.5% of the annual growth for the year before the treatments, respectively. The cambial growth rate of stem (SGR) at 1.5 cm above the branch bark ridge and the closure rate of pruning wound (WCR) for one year after treatments were positively correlated, and WCR of P treatment of 39.8% was significantly higher than that of P+T treatment of 31.8%. Wounds of P+T treatment formed greater discolored area per unit area of pruning wound (D/W Ratio) than those of P treatment significantly. Lower WCR and higher D/W Ratio of P+T treatment suggested less ability of compartmentalizing the wounds than P treatment. Total phenols at branch core of pruning wound for both treatments heightened a month after treatment, and then lowered. The contents at below core of the wound were higher than those at control ones continuously, while they became similar each other at above core. Relatively high phenol contents of the extractives at P+T treatment implied that trees with P+T treatment allocated more energy to compartmentalize their wounds. Holocellulose and lignin contents at the branch core of treated branch unions of both treatments were lower and higher, respectively, than at the same part of the union with living branch, as results of the tree reaction to protection from wounding and microbial invasion.

• 대한심미치과학회지
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• 제8권1호
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• pp.18-27
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• 1999

A tooth solely can not be an exclusive factor to attain our goal, esthetics. Other consideration, such a proportion of individual tooth, harmonized arrangement of the dentition and surrounding tissues including gingiva, lip and face should be taken into account. Esthetic gingival pattern and incisal level in the anterior area are the very important factors for esthetic restoration of the smile. We often propose adequate periodontal and prosthodontic approaches in order to improve the esthetics of the anterior area. Here, I would like to share some cases which include soft tissue management for ovate pontic placement, osteoplasty, resin filling for severe cervical caries, and bleaching approach to discolored root caused by endodontic treatment, and so on.

• 한국음향학회지
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• 제33권1호
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• pp.21-30
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• 2014

음향감쇠매질 내에서 집속 초음파에 의한 온도 분포 변화를 파악하는 것은 다양한 분야에 매우 중요한 정보를 제공할 수 있다. 본 연구는 음향감쇠매질 내에 임계온도 $30^{\circ}C$인 시온안료를 사용한 감온 필름을 삽입하여 비침습적으로 온도 상승 효과를 조사하였다. 음향감쇠매질은 한천과 설탕을 섞어 제작하였으며 매질내 음향특성을 제어하기위해 사용한 설탕 농도는 25 %에서 40 %까지 변화시켰다. 집속 초음파에 의한 온도상승 효과를 감온 필름의 변색영역의 변화로 관찰한 결과 초음파 방사 후 2~5 s 사이에 급격한 변색 영역의 증가를 보이다가 그 이 후 완만한 변화를 보였다. 시뮬레이션에서는 실험 결과와는 달리 초음파 방사후 10 s까지 선형적으로 변색영역이 증가하는 경향을 보였다. 이는 매질의 열전도도 및 열용량은 온도에 따라 변하는 값을 가지는데, 시뮬레이션에는 이를 고려하지 못했기 때문으로 사료된다.