Er:YAG 레이저의 상아질 삭제효과 및 이에 따른 온도변화

임광호,이창섭,이상호 대한소아치과학회 2001 大韓小兒齒科學會誌 Vol.28 No.1

Er:YAG 레이저의 상아질 삭제효과와 이에 따른 온도변화를 평가하고자 발거된 소구치와 대구치로 상아세관내 조직액과 치수내압을 유지할 수 있는 상아질 시편을 제작하고 2.94㎛의 pulsed Er : YAG 레이저 (SDL-300EN, 삼성전자, 한국)를 handpiece형의 전달계를 이용한 비접촉식 방법으로 조사세기, pulse repetition rate, 조사시간, 물 분사여부 등의 조사조건을 달리하여 상아질 면에 조사하고 이때의 삭제량과 상아질 두께에 따른 온도변화, 그리고 삭제형태를 조사, 분석하여 다음과 같은 결과를 얻었다. 1.레이저 조사세기와 pulse repetition rate가 클수록, 그리고 조사시간이 길수록 삭제량이 증가되었다(P〈0.05). 그러나 5Hz의 pulse repetition rate에서는 조사시간에 따른 삭제 량의 차이가 크지 않았다. 2.삭제된 와동은 비교적 변연부가 명확하고 깨끗하였으며 와동의 바닥은 원추형이였으며 부드러웠다. 조사세기와 pulse repetition rate가 클수록, 그리고 조사시간이 길수록 와동의 상부 직경이 넓었으며 150mJ, 5Hz, 5sec에서는 와동변 연부에 약간의 crack이 관찰되었다. 3. 레이저 조사세기와 pulse repetition rate가 클수록, 그리고 조사시간이 길수록 상아질의 온도가 더 많이 상승하였으며 시편의 두께가 두꺼울수록 온도상승이 적었다(P〈0.05). 4.물을 분사하며 레이저를 조사할 경우 물을 분사하지 않은 경우에 비해 온도상승이 매우 감소되었다(P(0.05). 이상의 결과를 종합해 볼 때 Er : YAG레이저를 상아질에 조사할 경우 와동의 형태가 명확하고 물을 분사할 경우 온도상승이 많이 유발되지 않으므로써 삭제력이 좋고 치수에 유해작용이 없는 것으로 생각된다. 향후 임상에서 치질을 제거하는데 효율적으로 이용되기 위해서는 삭제력이 더욱 크고 이에 따른 온도상승을 최소로 할 수 있는 조사 시스템 및 방법에 대한 연구가 계속적으로 이루어져야 할 것으로 사료된다. The purpose of this study was to investigate the effects of Er : YAG laser on cutting efficacy and temperature changes of dentin. We used the dentin specimens of human premolars and molars which contain the physiologic saline and maintain the pulpal pressure in dentinal tubules. Each specimen was exposed to Er : YAG laser with non-contact handpiece type delivery system under different treatment condition of irradiation energy, pulse repetition rate, and exposure time. Two procedures were conducted by the presence of water flow during lasing. The specimens were grouped by thickness of dentin. We investigated the cavity pattern, volume, and temperature change of dentin specimen to determine the cutting efficacy and temperature rise of Er : YAG laser, and obtained following results. 1.Cutting volume of dentin was increased by increasing the irradiation energy, pulse repetition rate, and exposure time(P〈0.05). 2. Margins of abulated cavities were sharp and clean and floors of cavities were conical in shape and showing smooth surfaces. Upper diameter of abulated cavities were increasing as laser parameter of irradiation energy, pulse repetition rate, and exposure time were increased. A few cracks were observed on abulated surfaces under treatment condition of laser parameter with 150mJ, 5Hz, and 5sec. 3.Temperature was increased as laser parameter of irradiation energy, pulse repetition rate, and exposure time were increased, and temperature rise was decreased as dentin thickness was increased(P〈0.05). 4.Temperature rise was decreased under water flow compared with no water flow during laser exposure(P〈0.05). From these results, we think that the method of using a Er : YAG laser would be effective and safe in cutting dentin for clinical application.

전치의 후방견인에 따른 입술과 주위 연조직의 수직적 변화

강창수,김경호,최광철 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.2

입술의 돌출을 해소하고자 하는 환자들은 자신의 안모 개선을 안모의 측면보다는 거울로 볼 수 있는 정면을 통하여 느끼는 것이 보편적이다. 안모의 정면에서 평가가 이루어질 때에는 입술이 후방으로 들어간 정도와 함께 입술과 그 주위 조직의 수직적 변화에 의해서도 큰 영향을 받을 수 있으므로 교정치료 진단이나 치료 후 평가를 위한 측모두부방사선 사진 분석 시 전통적으로 중요시되고 있는 입술의 시상적 이동뿐만 아니라 흔히 간과하기 쉬운 수직적인 변화에 관해서도 평가가 이루어져야 한다. 따라서 본 연구에서는 입술 돌출을 주소로 내원한, 성장이 완료된 성인 여성 61명을 대상으로 측모두부 방사선 사진을 촬영하여 전치의 후방견인시 나타나는 입술과 주위 연조직의 수직적 변화를 계단식 다중 회귀 분석법을 이용하여 조사한 결과 다음과 같은 결론을 얻었다. 1.상, 하순의 philtrum길이 (SnLs, LiB') 는 전치의 후방견인 후 증가하였고, 상, 하순의 vermilion height (LsStms, StmiLi) 와 vermilion length (LsLi) 는 감소하였다. 2.상, 하순의 길이 (SnStms, StmiB')와 연조직의 하안면 고경 (SnMe')은 치료 후 유의성 있는 변화를 보이지 않았다. 3.상순의 philtrum길이 증가에 상악 전치의 정출 △UIV 이 가장 큰 영향을 주었으며 하순의 philtnlm길이 증가에는 치료 전 overjet이 가장 큰 영향을 주었다. 4.상, 하순의 vermilion height감소에 상순의 두께 감소가 가장 큰 영향을 주었다. Patients who want to reduce their lip protrusion usually estimate the severity of the lip protrusion on the frontal aspect. Most orthodontists have a perplexed experience of a reduced thin line of vermilion border on the frontal aspect as incisors are retracted, even though the lip protrusion is thought to be reduced favorably on the sagittal aspect. Some patients also look older after orthodontic treatment because of severe lip thinning. This unaesthetic reduction of vermilion border urges us to study the vertical lip change during orthodontic procedure. The purpose of this study was to evaluate the vertical lip and perioral soft tissue changes in respect to incisor retraction in an effort to analyze which factors might be responsible for their vertical changes, using the multiple regression analysis. The results were as follows. 1.Upper and lower lip philtrum length(SnLs, LiB') were increased after retraction of anterior teeth, where as upper and lower vermilion height(LsStms, StmiLi), and vermilion length(LsLi) were decreased. 2.Upper and lower lip length(SnStms, StmiB'), and soft tissue lower anterior facial height(SnMe') did not show any significant difference after treatment. 3.The increase of the upper lip philtrum length was mainly influenced by the extrusion of upper anterior teeth(△UIV), and the increase of the lower lip philtrum length was mainly influenced by the initial overjet before treatment. 4.The decrease of the upper and lower lip vermilion height was mainly influenced by the decrease of upper lip thickness.

의료정책에 따른 종합병원의 로비공간 변화

한광호,함욱,박창근,이낙운 江原大學校 産業技術硏究所 2004 産業技術硏究 Vol.24 No.B

The purpose of this study are observing changing direction of lobby space that happen by change of medical environment investigating lobby space of General Hospital by our country's medical policy change time and supply pabulum that need in forward Hospital Architecture planning. Results of this study are as follows ; Since Whole National Insurance enforcement from 1993 to 1995, form of general hospital lobby is form that outpatient entrance and inpatient entrance are detached. And lobby function divided to waiting space for medication, requisition space and also that is appearing being detached with rest space for user. ntil 1999 since 1996 that is since Medical Treatment Information System construction, the biggest characteristic of General Hospital lobby form is making Hospital Street itself do improving efficiency of flow planning being included in lobby

전국 응급의학과 수련병원의 응급실 병력지에 대한 분석

임태호,임훈,이종호,강형구,장문준,조광현,장석준,김승호,정상원 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: This study was designed to analyze the current emergency department(ED) medical records of teaching hospitals in Korea. Methods: The five-item questionnaires were mailed to the EDs of 40 hospitals. Among them, 27 questionnaires and 35 ED medical records were returned for reply rates of 67.5% and 87.5%, respectively. Results: 1) The actual number of data elements in the ED medical records used by each hospital varies widely. It ranges from 1 to 15 data elements with an average of 7.5 data elements. 2) Thirteen data elements, signature of nurse, checklist style in review of systems, checklist style in physical examination, neurologic examination, figure of face, Glasgow coma scale, trauma scale, treatment plan, mode of transfer, condition on transfer, documents sent with patient, condition on discharge or discharge instruction, use of pediatric chart and vaccination history are used by less than 50% of the medical records examined. 3) There was no difference in the total number of data elements or in redesign and computerization of ED medical record based on the location of the hospital, the type of hospital administration, or the number of years since the start of EM residency program. 4) There was a statistically increased number of data elements in redesigned medical records. 5) In the survey, 89% of the residents replied that medical records needed to be redesigned. With respect to uniformity, 58% of the residents disagreed. A well-designed checklist chart rather than a descriptive chart was preferred by 89% of the residents. Conclusion: The currently used ED medical records have much room for improvement. The age of the ED had little impact on the quality of ED medical records. More attention and effort in this field are needed. In addition, The Korean Society of Emergency Medicine should provide guidelines for ED medical records.

또래학습을 통한 또래교사와 또래학습자의 인지구조 변화 -초등 도형영역에 대하여-

김미정 ( Mi Jung Kim ),이광호 ( Kwang Ho Lee ),이미진 ( Mi Jin Lee ),성창근 ( Chang Geun Sung ) 한국수학교육학회 2013 初等 數學敎育 Vol.16 No.2

본 연구는 또래교수 활동을 통하여 변화된 도형의 개념 및 성질, 도형간의 관계에서 인지구조를 관찰하고 어떻게 정교화 해 가는지에 대해 또래교사와 또래학습자의 인지 구조의 차이를 알아보았다. 연구 문제를 해결하기 위해 보은의 S초등학교 5학년 학생 6명을 대상으로 또래교수와 학습자 3팀을 선정하고 도형영역에 대한 사전·사후검사를 실시하고 자료를 분석하였으며 심층면담을 실시하여 인지구조를 분석하였다. 또래교사와 또래학습자 모두 도형영역에서 인지구조가 변화되었으며 특히 또래교사의 인지구조의 변화가 더욱 뚜렷이 나타났다. 따라서 또래교수활동은 체계적인 계획하에 일관성 있는 교수활동 뿐만이 아니라 학습활동에 더욱더 많은 교사의 지속적인 노력과 지원이 필요하다. The purpose of the study is finding the effective teaching and learning methods on the concepts of figures through exploring the change of students` cognitive structures before and after the peer teaching activities. The difference of the peer teacher`s and student`s cognitive structures was investigated for the activities. Three teams, six students of 5th grade, were selected from the S elementary school in Boyeon. To figure out the students` cognitive structures, pre and post in-depth interviews were conducted and analyzed. Both peer teachers` and learners` cognitive structures were changed. Peer teachers` cognitive structures were changed more positively than peer learners. A consistent systematic planation and continuous teacher support and effort are needed for the activities.

소의 대동맥 내피세포에서 산화저밀도 지단백에 의한 아포프토시스에 백일해 독소 및 콜레라 독소가 미치는 영향

손호영(Ho Young Son),강성구(Sung Ku Kang),강무일(Moo Il Kang),차봉연(Bong Youn Cha),이광우(Kwang Woo Lee),장상아(Sang Ah Chang),최윤희(Yoon Hee Choi),문성대(Sung Dae Moon),안유배(Yoo Bae Ahn),손현식(Hyun Sik Son),윤건호(Kun Ho Yoon) 대한내과학회 1999 대한내과학회지 Vol.56 No.5

N/A Objectives : Oxidized LDL is thought to play a key role in atherogenesis. Among their wide variety of biological properties, oxidized LDL injures the endothelium as an early event of atherogenesis. However, the mechanisms by which oxidized LDL injures endothelial cells are not definitely known. In order to evaluate the involvement of GTP-binding protein on the mechanism of apoptosis, we studied the effects of pertussis and cholera toxin on oxidized LDL-induced apoptosis in bovine aortic endothelial cells(BAECs). Methods : Oxidized LDL elicited apoptosis in cultured BAECs as shown by characteristic morphological and biochemical changes. Chromatin condensation and nucleus fragmentation were visualized by using fluorescence microscopy of intact cells staining by acridine orange/ ethidium bromide. DNA fragmentation was quantified by an ELISA with specific antibody for bromodeoxyuridine- labelled DNA fragments and confirmed with DNA ladder formation. Results : Studies using a combination of bacterial toxins which change the function of GTP-binding protein suggest that oxidized LDL-induced apoptosis was regulated by GTP-binding protein. Oxidized LDL-induced apoptosis was not changed by pretreatment of BAECs with pertussis toxin. In contrast, pretreatment with cholera toxin completely prevented the oxidized LDL- induced apoptosis. Conclusion : These results show that oxidized LDL induces apoptosis of BAECs and suggest that cholera toxin-sensitive G-proteins are involved in signal transduction of oxidized LDL-induced apoptosis of BAEC.

광조사 강도가 복합레진의 중합반응속도에 미치는 영향에 관한 실시간 체적측정법을 이용한 연구

라성호,이인복,김창근,조병훈,이광원,손호현 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.2

Objectives The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system (the experimental equipment designed by DR. IB Lee) by which real-time volumetric change of composite can be measured. Methods Three commercial composite resins [Z100(Z!), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450mW^2) during 20 sec. Polymerization shrinkage of samples was detected continuously by IB system during 110 sec and the rate of polymerization shrinkage was obtained by its shrinkage data. Peak time(P.T.) showing the maximum rate of polymerization shrinkage was used to compare the polymerization rate. Results Peak time decreased with increasing light intensity(p<0.05). Maximum rate of polymerization shrinkage increased with increasing light intensity(p<0.05). Statistical analysis revealed a significant positive correlation between peak time and inverse square root of the light intensity (AF:R=0.965, Z1:R=0.974, SF:R=0.927). Statistical analysis revealed a significant negative correlation between the maximum rate of polymerization shrinkage and peak time(AF:R=-0.933, Z1:R=-0.892, SF:R=-0.883), and a significant positive correlation between the maximum rate of polymerization shrinkage and square root of the light intensity(AF:R=0.988, Z1:R=0.974, SF:R=0.946). Discussion and Conclusions The polymerization rate of composite resins used in this study was proportional to the square root of light intensity. Maximum rate of polymerization shrinkage as well as peak time can be used to compare the polymerization rate. Real-time volume method using IB system can be a simple, alternative method to obtain the polymerization rate of composite resins.

연구논문 : 친자연형 녹색방재 정책제안

장준호 ( Chun Ho Chang ),장광석 ( Kwang Seok Jang ),이영석 ( Young Seok Lee ) 한국환경정책학회 2010 環境政策 Vol.18 No.1

The term "Green Growth" was first used at The Fifth Ministerial Conference on Environment and Development in Asia and Pacific which was held in Seoul by UN Economic and Social Commission for Asia and Pacific, ESCAP. The Green Growth which breaks down the stereotype that green was not compatible with growth a paradigm to create a incredible synergy effect by the combination between green and growth. The most important concept of Green Growth is its win-win structure based on harmony between economic growth and environment management. But, nobody tell a defence system about new growth system, i. e green disaster prevention system for new generation. That`s why we are going to declare that green disaster prevention policies will be focused on the governmental rules, green IT, and ubiquitous. The details are as follows. At first, we reorganize the disaster prevention rules for climate change. Second, research fund should be increased for high tech green disaster prevention techniques. Third, we have to develop disaster prevention techniques by using the green Information technique(IT) tools. Fourth, Green Disaster Prevention system which use Ubiquitous should be constructed. It should be realized in the range that risk factors caused by economic activity do not go against nature. It makes people coexist with environment.

첨가제를 첨가한 TMA-포접화합물의 상변화에 관한 실험적 연구

김진흥,정낙규,김창오,박호진,강승현,김광일 朝鮮大學校 機械技術硏究所 2002 機械技術硏究 Vol.5 No.2

The purpose of this study is to investigate the propriety of TMA clathrate as a cold storage medium. Particularly, this is to examine the extent of subcooling improvement when the surfactants are added to the TMA clathrate, because water used cold storage material has low phase change temperature and subcooling. this study has been analysed and compared with TMA 30wt% clathrate how phase change temperature, subcooling and specific heat in the various concentrations are changed. This results view to be improved phase change temperature and subcooling of TMA30wt% as a cold storage medium, when it had some surfactant. Additionally, it is that surfactant must be controlled under available solution limit and study for new additive must be lasted to know its effect.

Usefulness of Skin Explants for Histologic Analysis after Fractional Photothermolysis

( Gyeong Hun Park ),( Sung Eun Chang ),( Seunghyun Bang ),( Kwang Hee Won ),( Chong Hyun Won ),( Mi Woo Lee ),( Jee Ho Choi ),( Kee Chan Moon ) 대한피부과학회 2015 Annals of Dermatology Vol.27 No.3

Background: Fractional laser resurfacing treatment has been extensively investigated and is widely used. However, the mechanism underlying its effects is poorly understood because of the ethical and cosmetic problems of obtaining skin biopsies required to study the changes after laser treatment. Objective: To evaluate the usefulness of human skin explants for the investigation of fractional photothermolysis. Methods: Full-thickness discarded skin was treated in 4 ways: no treatment (control), fractional carbon dioxide laser, fractional Er:YAG laser, and fractional 1,550-nm erbium- doped fiber laser. Both treated and non-treated skin samples were cultured ex vivo at the air-medium interface for 7 days. Frozen tissue was sectioned and stained with hematoxylin & eosin for histologic examination and nitro blue tetrazolium chloride for viability testing. Results: Skin explants cultured for up to 3 days exhibited histologic changes similar to those observed in in vivo studies, including microscopic treatment zones surrounded by a thermal coagulation zone, re-epithelialization, and formation of microscopic epidermal necrotic debris. However, the explant structure lost its original form within 7 days of culture. The viability of skin explants was maintained for 3 days of culture but was also lost within 7 days. Conclusion: The skin explant model may be a useful tool for investigating the immediate or early changes following fractional photothermolysis, but further improvements are required to evaluate the long-term and dermal changes. (Ann Dermatol 27(3) 283∼290, 2015)