산업자재용 폴리에스터 섬유의 강도 향상에 관한 연구

박영신,남영식,정상영,최재호,장기혁,박원호,Park, Young-Shin,Nam, Young-Sik,Jung, Sang-Young,Choi, Jae-Ho,Jang, Ki-Hyuk,Park, Won-Ho 한국섬유공학회 2012 한국섬유공학회지 Vol.49 No.1

In this work, effects of total draw ratio change on the mechanical properties of polyester fibers were studied. The process parameter was a total draw ratio and the draw ratios that were used ranged from 6.6 to 7.0. Tensile properties are determined from the tensile tester, and crystallite parameters from the density measurement and X-ray diffraction were discussed with the different total draw ratios. The tenacity, young's modulus and crystallinity were increased to 10.6 g/d, 123.2 g/d and 42.1%, respectively, with increase in the total draw ratio. The relations between total draw ratio and mechanical properties of high tenacity polyester fiber were discussed.

Trichophyton verrucosum infection in Korea: Analysis on 224 patients from 1976 to 2015

( Dong Hyuk Eun ),( Jun Hong Park ),( Sun Young Moon ),( Yong Hyun Jang ),( Seok-jong Lee ),( Do Won Kim ),( Yong Jun Bang ),( Jae Bok Jun ),( Weon Ju Lee ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.2

Background: Trichophyton (T.) verrucosum is a dermatophyte causing ringworm in cattle, distributed worldwide. It can be responsible for various inflammatory lesions of skin and scalp. In Korea, kerion celsi caused by T. verrucosum was first reported at 1986 in the southeast province of Korea. Since then, many patients infected with T. verrucosum have been reported in Young-nam province. There are few long-term studies about epidemiological characteristics of T. verrucosum. Objectives: To investigate the clinical and epidemiological characteristics of T. verrucosum infections in Korea. Methods: A total of 224 patients were diagnosed as T. verrucosum infection by fungal culture from 1976 to 2015. The data were based on a retrospective survey of medical records. Results: The annual incidence of patients with T. verrucosum infection had been increasing since the report in 1986. The number of patients showed a peak in 1988. After 2000, the number of patients had been decreasing. Female to male ratio showed a 1.2-fold predominance of female infection. And more than 15-year-old group was 59.4% of total patients. T. verrucosum infection was most commonly seen in spring and was found predominantly in patients living in rural areas. Face was most frequently involved, followed by arms. Conclusion: These findings provide useful information for understanding of T. verrucosum infection and future dermatophytosis prospects.

APF Gel이 심미 수복재료의 표면에 미치는 영향

최원혁,김은정,김현정,김영진,남순현 大韓小兒齒科學會 2006 大韓小兒齒科學會誌 Vol.33 No.2

현재 소아치과 영역에서 소아의 치아 우식증을 예방하기 위해 다양한 불소 도포법이 시행되고 있다. 이들은 법랑질 내 불소함량을 증가시키고 보다 안정된 결정 구조를 형성하게 하여 치아 우식증을 예방한다는데 근거하고 있다. 하지만 최근에 불소 도포제재가 심미 수복재료의 표면에 부작용을 일으킬 수 있다는 문제가 제기되고 있다. 이에 본 연구는 수종의 심미 수복재료의 표면에 APF gel이 미칠 수 있는 영향을 주사 전자 현미경을 통해 관찰하고 표면 조도를 측정한 후 비교 분석하여 다음과 같은 결과를 얻었다. 1. glass ionomer cement와 compomer를 이용한 실험에서 APF gel 4분 침적군과 pH 순환군은 인공타액 침적군에 비해 표면 조도가 증가하였다(p<0.01). 2. composite resin 인 Charisma와 Z250을 이용한 실험에서는 모든 군간의 표면 조도의 차이는 없었다(p>0.05). 3. 주사 전자 현미경으로 관찰한 결과 glass ionomer cement, compomer, composite resin의 순으로 filler의 소실이 많았으며 군별로는 pH 순환군, APF gel 4분 침적군, 인공타액 침적군의 순으로 filler의 소실이 많았다. Topical fluoride application for children is a widely performed procedure in the field of Pediatric Dentistry for its dental caries prevention effects. However, it is recently recognized as having some unwanted effects on several esthetic restorative materials, the author immersed glass ionomer cement, compomer and composite resin specimens in APF gel and measured the surface roughness and also, examined the specimens under the scanning eletron microscope. The followings are the results: 1. In the specimens of glass ionomer cement and compomer, APF gel 4 minute immersion group and pH cycling group show statistically significant increased surface roughness than artificial saliva immersion group(p<0.01). 2. There was no statistically significant surface roughness for composite resin in all group(p>0.05). 3. When the specimens were examined under scanning electron microscope, the surface change were in the order of glass ionomer cement, compomer, composite resin and also in the order of pH cycling group, APF gel 4 minutes immersion group, artificial saliva immersion group.

상악 정중이개 치료시 rubber band의 부적절한 사용 : A CASE REPORT

최원혁,김은정,김현정,김영진,남순현 大韓小兒齒科學會 2005 大韓小兒齒科學會誌 Vol.32 No.3

정중이개란 상악 중절치 사이의 치간이개를 말한다. 이는 혼합 치열기에서 ugly ducking stage에 흔히 관찰할 수 있으며 일반적으로 견치가 맹출하면서 자연적으로 소실되므로 꼭 치료가 필요한 것은 아니다. 그러나 견치 맹출 후에도 정중이개가 2mm이하로 계속 존재하거나 견치 맹출 전이라도 3mm이상의 정중이개가 존재하는 경우에서는 치료의 적응증이 될 수 있다. 특히 후자의 경우 심미적인 면에서 뿐만 아니라, 이로 인해 측절치와 견치의 맹출공간이 부족해지는 문제가 발생하므로 교정치료가 권장된다. 정중이개 치료시 사용되는 장치물은 finger spring 등을 이용한 가철성 장치물과, 교정용 band, tube, bracket 등을 부착시켜 rubber elastics이나 coil spring 등을 사용하는 고정성 장치물로 나뉘어진다. 그러나 정중이개의 치료를 위해 rubber band를 band, tube, bracket 등과 같은 적절한 부가장치 없이 사용하면 rubber band가 치근은 따라 치은 하방으로 이동하게 되고 치주 인대를 파괴하며 치근단 부위에 이르러 치아동요, 치아정출 및 탈락 등 치아에 치명적인 손상을 입힐 수 있다. 본 증례는 정중이개의 치료를 위해 부적절하게 rubber band를 사용하여 외상을 받은 치아를 관찰하여 다소의 지견을 얻었기에 이를 보고하는 바이다. Maxillary median diastema is the term used when there is spacing between maxillary central incisors. The space between maxillary central incisors are often observed during ugly duckling stage. In most of the cases, as maxillary permanent canines erupt, it gradually disappears. Maxillary median diastema needs to be treated when there is up to 2mm of space between the incisors even after eruption of permanent canines or when there is 3mm of space, at least, before the eruption of the canines. Particulary, for the latter case, orthodontic treatment is recommended because not only the esthetic point of view but also to regain the eruption space for maxillary lateral incisors and canines. The appliance used for orthodontic treatment are removable appliances, using finger spring and etc, and fixed appliances, using rubber elastics and coil spring. If rubber band alone was used to treat median diastema without any other appliance such as band, tube or bracket, it will gradually move downward along the root surface. Then it will destroy the peridontal ligament and causes tooth mobility, extrusion, and avulsion. This report presents cases of damaged tooth due to improper use of rubber band when treating maxillary median diastema.

클로르헥시딘 바니쉬의 적용이 교정용 브라켓의 전단접착강도에 미치는 영향

임동혁,김태우,장영일,남동석,양원식,백승학 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.2

본 연구의 목적은 클로르헥시딘 처리가 교정용 브라켓의 전단접착강도와 탈락 양상에 미치는 영향을 비교하는 것이다. 실험군으로 4주간 4회의 클로르헥시딘 바니쉬를 도포한 22개의 사람 소구치를 선택하였고, 대조군으로 아무 처리도 하지 않은 22개의 사람 소구치를 선택하였다. 모든 치아는 37%의 phosphoric acid gel로 부식시키고 교정용 브라켓을 같은 조건으로 부착시켰다. 전단접착강도의 측정을 위해 Instron universal testing machine(model 4466)을 이용하였고, 법랑질과 브라켓 표면은 SEM으로 관찰하였다. 결과의 분석은 t-test를 이용하였으며 결과는 다음과 같다. 1.클로르헥시딘의 법랑질 처리는 전단접착강도에 영향을 미치지 않았다. 2.클로르헥시딘으로 법랑질을 처리한 경우와 그렇지 않는 경우에 브라켓 탈락 양상에 차이가 없었다. 따라서, 클로르헥시딘으로 법랑질을 처리하여도 브라켓 접착에 유해한 작용이 없었고, 따라서 임상사용에 적합하다고 생각된다. The purpose of this study was to determine whether the application of chlorhexidine varnish affects the shear bond strength and failure pattern of orthodontic brackets or not. The experimental group consisted of 22 human premolars which extracted after chlorhexidine vanish application(4 times for 1 week interval) in vivo, and the control group consisted of 22 human premolars which extracted without any pre-treatment. After all teeth were etched with 37% phosphoric acid gel, metal orthodontic brackets (Q-3002, RMO, USA) were bonded to each tooth using auto-polymerizing orthodontic resin (Ortho-One, Bisco, USA) with the same bonding procedure. The shear bond strength was measured with Instron universal testing machine (model 4466, Instron Ltd., England), and the failure pattern of each bracket was examined with Scanning Electron Microscope (SM 840A, JEOL, Japan). The data were analysed statistically with t-test. The results were as follows : 1.Application of chlorhexidine varnish had no significant effect on the shear bond strength of the orthodontic bracket. 2.There was no significant difference in the failure pattern of orthodontic bracket between the experimental group and the control group.

GMS-5 가시영역 자료를 이용한 해면 일사량 추정

박경원,권병혁,김영섭 한국지리정보학회 2003 한국지리정보학회지 Vol.6 No.2

해상에서 1997년 1월부터 12월까지 맑은 날과 구름이 많은 대기상태에서 GMS-5에 장착된 VISSR(visible and infrared spin radiometer) 자료를 이용하여 5㎞×5㎞ 격자의 공간 분해능에서 태양복사를 추정하였다. 섬에 설치되어 있는 기상청의 pyranometer 자료로 추정 일사량을 검증하였다. 추정된 시간별 일사량의 RMSE(root mean square error)는 104W/㎡이고, 상관계수는 0.91이었다. 한반도 부근의 해상에서 조사된 시간별 태양복사의 최대값은 황해와 동해에서 6월에 나타나고, 남해에서는 8월에 나타나는데, 이는 6월에 저기압과 전선에 의한 기상 악화에 기인한다. Surface solar radiation over the sea is esitimated using the visible and infrared spin scan radiometer (VISSR) data onboard Geostationary Meteorological Satellite (GMS)-5 from January 1997 to December 1997 in clear and cloudy conditions. The hourly insolation is estimated with a spatial resolution of 5km×5km grid. The island pyranometer operated by the Japan Meteorological Agency(JMA) is used to validate the estimated insolation. The root mean square error of the hourly estimated insolation is 104W/㎡ with 0.91 of the correlation coefficient. In the variability of the hourly solar radiation investigated around the Korean Peninsula, the maximum value of solar radiation is hound in June at the Yellow Sea and the East Sea, while in August at the South Sea because of low pressure conditions and front in June.

A case of self-healing juvenile cutaneous mucinosis

( In Hyuk Kwon ),( Dae Yeon Kim ),( Dong Won Lee ),( Tae Hyung Ryu ),( Jae Eun Choi ),( Soo Hong Seo ),( Young Chul Kye ),( Hyo Hyun Ahn ) 대한피부과학회 2016 대한피부과학회 학술발표대회집 Vol.68 No.1

Self-healing juvenile cutaneous mucinosis is a very rare, self-limiting disease characterized by transient cutaneous lesions that affects the young. This disorder is characterized by rapid onset of asymptomatic papules and nodules on the face, periarticular regions, abdomen, and thigh. As implied by the name, the lesions spontaneously resolve over weeks to months. In contrast to mucinoses affecting adults, Self-healing juvenile cutaneous mucinosis has not been associated with systemic disorders such as paraproteinemia, bone marrow plasmacytosis, or thyroid diseases. A 7-year-old male presented with erythematous papules, multiple subcutaneous nodules on trunk and both arms that began 6 days before. Aside from pruritus of lesions no other symptoms were manifested. Histopathology showed microabscess in epidermis, superficial perivascular lymphocytic infiltration, and mucin deposition in dermis On follow up visit, although new lesions were present, previous lesions were subsiding. In consideration of the clinicopathological features, the diagnosis of self-healing juvenile cutaneous mucinosis was made. The patient is under close observation with no specific treatment. Herein, we report a rare case of self-healing juvenile cutaneous mucinosis. Knowledge of this entity may prevent unnecessary diagnostic testing and aggressive treatment in the pediatric population with this self-limited disease.

삼출성 중이염 환자에서의 혈중 및 아데노이드 면역글로불린 E의 면역혈청학적 연구

장혁순,강성호,유창수,김성현,이병돈,박영진,윤세동,안희영,강주원 순천향의학연구소 1997 Journal of Soonchunhyang Medical Science Vol.3 No.1

Otitis media with effusion (OME) is one of the most common disease in children but its pathogenesis is not clear. In particular the role of allergy has revealed conflicting support with widely varing opinions as to its importance. Within recent years, striking biochemical and immunochemical analytic techniques have opened a new approach the study of otitis media with effusion. So we focused on distributions of IgE in adenoid tissue and serum IgE levels. Authors compared the serum IgE and the distribution of IgE in adenoid tissue between the 20 patients underwent tonsillectomy, adenoidectomy and ventilating tube insertion and control group of 11 patients underwent tonsillectomy and adenoidectomy. The results were as follows; 1. In the distribution of IgE in adenoid tissue, there was a significant increase in the group of patients with OME compared to the control group (P<0.01). 2. In the analysis of serum IgE levels, the levels of IgE in the OME patients an control group were higher than normal level, although the level of IgE in the OME patients were less than that of control group, there was no significance P>0.05).

관상동맥 내 빛간섭단층촬영술을 활용한 관상동맥 내 석회화 병변의 중재시술 후 경과 예측: 전향적 관찰 연구

장지홍,강시혁,조영석,신은석,서정원 순천향대학교 순천향의학연구소 2021 Journal of Soonchunhyang Medical Science Vol.27 No.1

Objective Imaging modalities such as intravascular ultrasonography or computed tomography or angiography have shown limitations in assessing coronary calcification. In this study, we investigated whether quantitative indices of optical coherence tomography (OCT) in calcified lesions are correlated with the late outcome of a coronary stent. Methods We consecutively enrolled patients who had more than grade 2 coronary calcification on fluoroscopy. OCT was performed at baseline, immediately after stenting, and at 9 months after stenting. We analyzed qualitative and quantitative characteristics of plaque, calcification, and stent-related indices. Results All images of 3-time points were available in a total of 10 patients. Calcified lesions were frequently associated with thin cap fibroatheroma (100%), plaque erosion (20%), or rupture (20%) before the procedure. Thrombus was found in 100% of cases in the OCT immediately after stenting. Maximal calcium area before stenting was strongly correlated with late luminal loss assessed by 9-month follow-up OCT (r= 0.766, P= 0.01). Conclusion Preprocedural OCT assessment on calcified coronary lesion may predict high-risk procedure and late stent outcome. Further studies are warranted to confirm these findings.

선인장 양심실 보조장치의 설계 및 임상적용을 위한 평가

민병구,박찬영,최재순,이혁수,황창모,김삼성,윤걸중,김종원,선경,이경갑,정종태,김원곤 제주대학교 인공심장이식연구소 2001 인공심장 연구 Vol.2 No.1

현재 개발되고 있는 맥동형 이식형 인공심장은 완전이식형 인공심장과 좌심실보조장치 뿐이다. 좌심실보조장치를 장착한 환자의 10~15%가 우심실의 보조를 필요로하고 완전이식형 인공심장의 장착을 위해서는 자연심장을 제거해야하는 상황에서 이식형 양심실보조장치에 대한 필요성이 대두되고 있다. 본 연구진은 완전이식형 인공심장으로 개발된 한국형 인공심장을 개선하여 양심 실 보조장치를 개발하였다. 양심실보조장치는 이동형 작동기식 미케니즘을 이용하고 있으며 에너지 변환장치와 감속기로 구성된 작동기와 혈액주머니, 그리고 내장형 제어기로 구성되어 있다. 선인장 펌프로 명명된 KAH350은 캐뉼라의 연결을 위한 커넥터를 포함하여 길이 177mm, 폭 164mm, 높이 67 이고 무게 780g이며 최대 심박출량은 5L/min 이다. 양심실보조장치로 개발된 선인장펌프는 좌심실보조장치로도 응용이 가능하다. 이식적합성과 생체적합성을 평가하기 위하여 좌심실보조장치로 5회, 양싱실보조장치로 6회의 동물실험을 수행하였다. 각각 최장 28일간 생존하였으며 11회의 동물실험중 장치의 결함에 의한 것이 3회 있었는데 이들은 모두 전자장치의 결함과 방수처리문제였다. 현재 이식적합성과 일박출량을 향상시킨 KAH400모델이 개발중이다. The types of pulsatile implantable artificial hearts that are on the way of development and have been developed are totally implantable artificial heart and implantable left ventricular assist device (LVAD). Approximately 10% to 15% of all patients Implanted with wearable VADs have required right heart support with another device. And it is reluctant to patient who should remove his or her own heart to be implanted with total artificial heart. These situations drive the development of implantable bi-ventricular assist device (BVAD). The Korean BVAD was develophed by modifying the moving actuator type Korean artificial heart. This electro-mechanical BVAD comprises actuator including energy converter and reduction gear train, blood sacs, and internal motor and energy controllers. The KAH350 which is named as 'Cactus Pump' is 177mm in length, 164mm in width, and 67mm in thickness including connectors and nuts. The weight and maximum cardiac output of Cactus Pump is 780g and 5L/min, respectively. The Cactus Pump that was developed as BVAD could be used as LVAD by attaching compliance caps on the 2 ports of one ventricle. The animal experiments were undergone 5 times for LVAD, and 6 times for BVAD. The best records were 28 days survival in both applications. There were 3 times of device failure and they were all associated with electrical connection and hermetic sealing. The KAH400 that has improved anatomical fitting characterisitcs and stroke volume is on development.