• 한국소음진동공학회논문집
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• 제15권5호
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• pp.527-535
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• 2005

This paper explains a general coupling system in terms of the system parameters. impedance of a cavity or mobility of a structure. To easily access the mechanism of the structural-acoustic coupled system, a simple expression is derived. A general coupled equation is also derived of a general coupled problem constituted a flexible structure and an opening boundary in terms of vector and matrix notation, and is analyzed the coupling phenomena using the understanding acquired simple coupled system. The paper shows that the general coupled equation is expanded version of the simple coupled equation by some limiting checks. The paper also shows that the degree of coupling is proportioned to a stiffness of the acoustic system and a modal coupling coefficient, but is in inverse proportion to a mass of the structural system and the difference of the excitation frequency and resonant frequency of the acoustic or structural system.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.377-386
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• 1993

The purpose of this study was to evaluate the disinfection efficacy of root canal irrigation method and irrigation solution in infected root canals. Access cavity were prepared in single-rooted extracted human teeth and each canals were prepared with step-back method and sterilized with ethylene oxide gas. Prepared teeth were experimentally inoculated in the canals for 30 minutes with four aerobes(Streptococcus mutans, Stapylococcus aures, Streptococcus sanguis, and E. coli) and two anaerobes(Streptoccus intermedius, and Clostrium perfringens). Normal saline, 3% $H_2O_2$, and 3% NaOCl were used as irrgation solutions. And root canals were irrigated with each irrigation solutions manually with disposible syringe or ultrasonic instument. (Apoza Uitrasonc, Taiwan). The irrigation effect on the eradication of S. aures and S. intermedius with normal saline was not similar between manual method and ultrasonic method. No significant differences were observed in the eradication of E. coli and C. perfringens among the irrigation solution and irrespective of the irrigation methods. In S. aurues and S. mutans, there was somewhat different eradication effect according to irrigation solutions, but there was no significant difference between manual method and ultrasonic methods. These results suggest that ultrasonic irrigation method with saline is more effective in some strains than manual irrigation.

• 대한두경부종양학회지
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• 제35권2호
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• pp.1-10
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• 2019

The 2019 American Society of Clinical Oncology (ASCO) Annual Meeting, which took place May 31-June 4 in Chicago, drew more than 32,000 oncology specialists from around the world. The theme of 2019 ASCO conference was "Caring for Every Patient, Learning from Every Patient". Among the topics of interest covered were new approaches to surmount limited access to cancer care and the latest advances in targeted therapies for pancreatic, prostate cancers and soft tissue sarcomas. In the field of head and neck cancer, 8 oral abstracts and 75 poster abstracts were presented at this meeting. In this review, we are going to summarize the eight studies that have been presented orally. The topics are recurrent and/or metastatic head and neck squamous cell carcinoma for two abstracts (#6000, #6002), salivary duct carcinoma for one abstract (#6001), locally advanced nasopharyngeal carcinoma for two abstracts (#6003, #6004), oropharyngeal carcinoma for two abstracts (#6006, #6008), and oral cavity cancer for one abstract (#6007).

• Maxillofacial Plastic and Reconstructive Surgery
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• 제21권2호
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• pp.225-230
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• 1999

The labiomandibulotomy approch to the oral cavity and oropharygeal region was first described by Roux in 1836 and become popular for oral and oropharyngeal tumors in cases where there are no clinical and radiological signs of mandible invasion. Anterior labiomandibulotomy and swing procedure provides excellent access and facilitate a mandibular resection and subsequent repair. In last two years, 8 cases of oral and oropharyngeal tumors were treated by this approach at the Dept. of Oral & Maxillofacial Surgery, Holy Family Hospital, Catholic University of Korea. And we analyzed postoperative complications as well as functional evaluations, and the results were as follows; In 4 cases, marginal mandibulectomy were combined with labiomandibulotomy and in case of malignancies, neck dissection was performed simultaneously. In almost case, plate and miniscrew fixation was used for osteotomy sites. Histologic evaluation of the resection margins of the specimens revealed tumor free in all cases. The postoperative complications were occured in 3 cases, one case of nonunion, one case of orocutaneous fistula, and one case of wound dehisence. Occlusal stability, jaw movement and swallowing function were acceptable postoperatively in 3 months. From above results, we concluded that, this approach not only provides wide exposure, permitting radical removal of benign and malignant lesions but also preserves function with minimal complications.

• ETRI Journal
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• 제38권1호
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• pp.9-17
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• 2016

We demonstrate a time- and wavelength-division multiplexed passive optical network system employing a vertical-cavity surface-emitting laser array-based optical line terminal transceiver and a tunable bidirectional optical subassembly-based optical network terminal transceiver. A packet error-free operation is achieved after a 40 km single-mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal-oxide-semiconductor photonics technologies, and low-cost key devices for deployment in access networks.

• Restorative Dentistry and Endodontics
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• 제24권1호
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• pp.166-179
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• 1999

외과적 근관치료에서 근단부의 폐쇄성은 성공에 필수적이다. 그리고 외과적 근관치료시 근단부 역충전와동은 습기나 혈액에 의해 오염되기 쉬우며 와동을 이상적으로 건조하기가 항상 용이하지는 않다. 본 연구의 목적은 미세 치근단 수술법에서 치근단 역충전와동의 건조 방법이 폐쇄성에 미치는 영향을 연구하고자 함이다. 치근단 폐쇄성은 근단 누출 및 충전물-와벽 적합성으로 평가하였다. 치근단 역충전와동 건조방법에 따른 치근단 누출을 평가하기 위해서는 최근에 발거된 상악 대구치 구개측치근 125개를 와동건조 방법 및 혈액오염에 따라 4개의 군으로 분류하여 실험하였다. 각 시편치아에서 근관을 형성하고 측방가압법으로 충전한 후 각 군에 따라 저속 다이아몬드 절단기를 이용하여 치근단 3 mm를 절제하였으며 초음파 스테인레스 스틸 기구를 이용하여 깊이 3mm의 역충전 와동을 형성하고 IRM, Super EBA 또는 복합레진으로 역충전하였다. 시편을 2% methylene blue 용액에 7일간 침잠시킨 후 35% 질산 용액에서 용해시킨 다음, 원심분리한 상층액을 비색계를 이용하여 누출 색소의 흡광도를 측정하였다. 결과치는 이원변량분석법과 Duncan's Multiple Range Test를 이용하여 분석하였다. 역충전 와동 건조방법에 따른 충전물-와벽 적합성을 평가하기 위해서는 상악 제 1대구치의 구개측 치근 12개를 상기와 같이 4개 군으로 분류하여 근관충전, 역충전와동 형성, 와동 건조 및 역충전을 실험하였으며, 다음과 같은 결과를 얻었다. 1. 압축공기나 paper point로 와동을 건조한 군이, 역충전 와동을 IRM 간이충전재, Super EBA 시멘트 및 복합레진으로 충전한 경우 공히, cottton pellet 만으로 와동을 건조한 군에 비해 적은 치큰단 누출을 나타내었는데 이는 Super EBA 시멘트 충전군에서만 유의한 차이를 나타내었다(p<0.05). 그러나 충전재료에 관계없이 paper point로 와동을 건조한 군과 압축공기로 건조한 군 사이에는 유의한 누출의 차이가 나타나지 않았다. 2. 압축공기로 와동을 건조한 경우에는, 복합레진으로 충전한 군이 IRM이나 Super EBA로 충전한 군에 비해 유의하게 적은 치근단 누출을 나타내었다(p<0.05). 3. 와동을 혈액으로 오염시킨 경우에는, 역충전 와동을 IRM, Super EBA 및 복합레진으로 충전한 군 공히, 압축공기로 와동내부를 건조한 경우에 비해 유의하게 많은 치큰단 누출을 나타내었다(p<0.05). 4. IRM 간이충전재나 Super EBA 시멘트로 역충전와동을 충전한 경우, 와동측벽의 외측 1/2이 내측 1/2에 비해 넓은 충전물-치질 사이 틈을 나타내었다. 5. IRM 간이충전재, Super EBA 시멘트 및 복합레진으로 역충전와동을 충전한 경우 공히, 와동이 혈액에 의해 오염되었거나 와동을 cotton pellet으로만 건조한 경우가 paper point나 압축공기로 와동을 건조한 경우에 비해 와동기저부에 큰 틈을 나타내는 양상을 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4769-4774
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• 2013

This paper is the first to present the incidence and overall survival of patients with squamous cell carcinoma of the head and neck (SCCHN) from the extreme northern part of the Philippines. We retrospectively retrieved the records of patients with histologically-confirmed squamous cell carcinoma of the oral cavity, oropharynx, hypopharynx and larynx at the Mariano Marcos Memorial Hospital and Medical Center, Ilocos Norte, Philippines, from 2003 to 2012 and analysed prognostic factors associated with survival. Of the 150 cases, only 80 (53.3%) were still living when the study was terminated. Median age at initial diagnosis was 61.5 years and the male to female ratio was 7:3. The majority of the cases had tumours in the oral cavity (50.7%), followed by the larynx (36.7%). Sex (log rank=1.94, p value/${\alpha}$=0.16), tumor site (log rank=0.02, p value/${\alpha}$=0.90), tumor grade (log rank=1.74, p value/${\alpha}$=0.42), and node stage (log rank=0.07, p value/${\alpha}$=0.80) were not shown to be associated with the survival of our cases. Only 45 (30.0%) had no regional lymph node involvement (N0) at presentation and 12 (8.0%) had already developed distant metastases. Among the 150 patients, 71 (47.3%) were not able to receive treatment of any kind. Oddly, treatment (log rank=1.65, p value/${\alpha}$=0.20) was also shown to be not associated with survival. The survival rate of those who underwent surgery, radiotherapy, or both was not statistically different from those who did not receive any treatment. Only the tumor stage (log rank=4.51, p value/${\alpha}$=0.03) was associated with patient survival. The overall mean survival was 49.3 months, with survival rate diminishing from 88.3% during the 1st year to 1.80% by end of the study. This relatively low survival rate of our cases only reflects their poor access to quality diagnostic and treatment facilities.

• 한국의학물리학회지:의학물리
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• 제12권1호
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• pp.9-17
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• 2001

본 논문의 목적은 조직(Tissue)에서의 광학적 특성(Optical Properties)을 이용한 광학적 생검(Optical Biopsy)방법을 소개하고, 방사선 치료에서 치료 반응 결과를 확인하는데 적당한 도구인가를 확인하고자 한다 본 연구는 구강(Oral Cavity) 내부조직을 샘플로, 건강한 사람 4명과 구강 암환자 4명의 자원을 받았다. 연구실에서 제작한 FastEEM(Excitation Emission Matrix) 장비를 이용하여 생체 내(in vivo)상태에서 측정하였다. 건강한 구강의 정상조직(Normal Tissue)과 병이 있는 구강의 비정상조직에서 기존의 생검과 동시에 새로운 광학적 생검을 하였다. 광학적 생검 결과와 기존의 생검 결과를 비교 확인하고, 암 조직으로 진단 받은 환자들에게 2차 광학적 생검을 실시하였다. 암 조직에 대한 1차 광학적 생검과 2차 측정 결과에 대한 형광스펙트럼을 비교 분석하였고, 자료분석은 Gillenwater가 개발한 337nm에 근거한 진단 알고리즘을 이용하였다. 광학적 생검 방법은 암 조직을 정상조직과 확실하게 구분시키는 장비임을 확인하였다. 건강한 구강조직과 악성 종양 조직의 측정 형광세기를 비교하면 정상조직인 경우 암 조직의 형광세기보다 모든 환자에 대해서 크게 나타났다. 암 조직의 구성이 시간에 따라 변하였을 때(7일) 광학적 생검을 하면 측정된 4명의 환자의 형광의 세기에 변화가 있었다. 7일간 시간이 지난 암 조직이 형광세기가 더 작은 값을 갖는다. 광학적 생검은 조직을 인체에서 분리하지 않는 생체 내, 실시간, 비침습성(noninvasive)생검 방법이다. 본 연구에서는 구강의 정상조직과, 암 조직, 그리고 암 조직의 진화에 따른 구성의 변화를 형광스펙트럼으로 확인하였다. 형광분광법을 이용한 FastEEM장치는 암 조직의 변화를 확인함으로 방사선 치료 후 발생하는 암 조직 구성의 화학적, 생물학적, 형태학적 변화를 실시간으로 정확하게 측정이 가능한 장치임을 확인하였다.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.247-251
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• 2001

;A dental developmental anomaly is defined as an isolated aberration in tooth form, caused by a disturbance or abnormality which occurred during tooth development. There are numerous types of dental anomalies, and a considerable variation in the extent of the defects occurs with each type. Teeth with these anomalies pose unique challenges. Since the defects are not always apparent clinically, they can confuse diagnosticians investigating the etiology of pulpal pathosis. When endodontic treatment is required, the defects often hinder access cavity preparation and canal instrumentation. Treatment planning also becomes more challenging, since the defects can create complicated periodontal problems, and the malformed teeth can be difficult to restore, particularly those weakened by endodontic therapy. Fusion is defined as the joining of two developing tooth germs resulting in a single large tooth structure. The incidence of fusion is < 1% in the Caucasian population, and it is believed that physical force or pressure produces contact of the developing teeth. Clinically and radiographically, a fused tooth usually appears as one large crown with at least partially separated roots and root canals. There may be a vertical groove in the tooth crown delineating the originally separate crowns. Dens invaginatus is a deep surface invagination of the crown or root that is lined by enamel. Teeth in both maxillary and mandibular arches may be affected, but the permanent maxillary lateral incisor is the tooth most commonly involved. Studies have revealed an incidence ranging from 0.25% to as high as 10%. The invagination ranges from a slight pitting to an anomaly occupying most of the crown and root. The invagination frequently communicates with the oral cavity, allowing the entry of irritants and microorganism either directly into pulpal tissues or into an area that is deparated from pulpal tissues by only a thin layer of enamel and dentin. This continuous ingress of irritants and the subsequent inflammation usually lead to necrosis of the adjacent pulp tissue and then to periapical or periodontal abscesses. If the invagination extends from the crown to the periradicular tissue and has no communication with the root canal system, the pulp may remain vital. Recommended treatment of fused tooth and dens invaginatus has been reported in the endodontic literature. This case report describes the endodontic treatment of a maxillary laterl incisors having fused crown and dens invaginatus.natus.

• 한국광학회지
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• 제16권1호
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• pp.13-20
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• 2005

광섬유 브라그 격자를 외부 공진기로 사용하는 레이저 다이오드(이하 FGL : fiber grating laser 이라 약칭함)를 제작한 후 그 성능을 실험적으로 측정하고 분석하였다. FGL을 WDM기반의 수동형 광 가입자망 시스템에 적용하기 위해서는 저가 구현이 필수적이며, 이를 위해, TO-CAN 형태의 모듈로 패키징하였다. 제작된 FGL의 동작 전류 대 광 출력 특성을 측정한 결과, $25^{\circ}C$에서 60 mA일때 약 3.6 mW를 얻을 수 있었고 주입 전류 변화에 따른 발진 파장의 변화율은 5.2 pm/mA이었다. 또한, FGL의 온도 변화에 따른 발진 파장의 변화율은 30 pm/$^{\circ}C$로 주변 온도 변화에 대한 발진 파장의 안정도가 매우 우수함을 확인하였다. 문턱 전류 이상의 동작전류 영역에서 각각 30 dB 이상의 양호한 주변 모드 억압비(SMSR)를 얻을 수 있었고, 단일 종 모드 발진 특성을 유지함을 확인하였다. 제작된 FGL의 전송 성능을 분석하기 위하여 155 Mb/s의 NRZ 신호로 직접 변조 실험을 수행하였다. BER 성능을 측정한 결과. 단일 모드 광섬유 20 km를 통과하더라도 광경로 파워 페널티가 발생하지 않았고 수신파워가 -37.5 dBm 이상에서 BER<$10^{-9}$ 을 얻을 수 있었다.