상악 영구 중절치의 외상성 치근파절 : 증례보고

최형준,곽지윤,이종갑,최병재,Choi, Hyung-Jun,Kwak, Ji-Youn,Lee, Jong-Gap,Choi, Byung-Jai 대한소아치과학회 2003 大韓小兒齒科學會誌 Vol.30 No.3

청소년기에는 두개악안면부위의 외상성 손상이 흔하다. 그러나 상아질, 백악질, 치수를 포함하는 치아파절로 정의되는 치근파절은 비교적 드물다. 치근파절에 대하여 취 할 수 있는 적절한 조치는 파절편의 치관부위를 재위치시키고, $2{\sim}3$달간 레진강선 고정술을 시행하는 것이다. 치수괴사나 치근흡수의 징후가 나타날때까지 근관치료를 보류해야 하는데 대부분의 증례에서 파절편의 치근부위는 그 생활력을 유지하기 때문이다. 본 증례의 10세 4개월된 남아는 상악영구중절치의 치근파절을 주소로 연세대학교 치과병원에 내원하였으며, 그후 7년동안 동일부위에 2번의 반복적인 외상이 있었으나 파절편 치관부의 재위치, 레진 강선 고정술, 근관치료 시행 후 임상적으로 방사선학적으로 비교적 양호한 치료결과를 얻었기에 보고하는 바이다. Traumatic injuries in the young permanent dentition are common, but root fractures, defined as fractures involving dentin, cementum and pulp, are relatively uncommon. Appropriate management of root fracture involves repositioning the coronal portion of the tooth fragment and firm immobilization with a splint for 2 to 3 month. Root canal treatment should not be initiated until the sign of necrosis or resorption are apparent because in most cases, the apical fragments maintain their vitality. The following case report describes a patient with root fractures injured three times over the period of 7 years. The results, clinically and radiographically, were acceptable, but long term periodic evaluation is required.

다양한 마취하 용량에서 케타민에 의해 유발된 청소년기 및 성체 마우스의 행동학적 변화

최형준,임수정,박해리,이성미,김철응,류승형,Choi, Hyung Jun,Im, Soo Jung,Park, Hae Ri,Lee, Seong Mi,Kim, Chul-Eung,Ryu, Seunghyong 대한생물정신의학회 2020 생물정신의학 Vol.27 No.1

Objectives Ketamine has been reported to have antidepressant effects or psychotomimetic effects. The aim of this study was to investigate the behavioral effects of ketamine treatment at various sub-anesthetic doses in adolescent and adult naïve mice. Methods In each experiment for adolescent and adult mice, a total of 60 male Institute of Cancer Research mice were randomly divided into 6 groups, which were intraperitoneally treated with physiological saline, 10, 20, 30, 40, and 50 mg/kg ketamine for consecutive 3 days. At 1 day after last injection, the locomotor and depressive-like behaviors were evaluated in mice, using open field test (OFT) and forced swim test (FST), respectively. Results In case of adolescent mice, ketamine dose was negatively correlated with total distance traveled in the OFT (Spearman's rho = -0.27, p = 0.039). In case of adult mice, we found significant positive correlation between ketamine dose and duration of immobility in the FST (Spearman's rho = 0.45, p < 0.001). Immobility time in the 50 mg/kg ketamine-treated mice was significantly higher compared to the saline-treated mice (Dunnett's post-hoc test, p = 0.012). Conclusions We found that the repeated treatment with ketamine could decrease the locomotor or prolong the duration of immobility in mice as the dose of ketamine increased. Our findings suggest that sub-anesthetic doses of ketamine might induce schizophrenia-like negative symptoms but not antidepressant effects in naïve laboratory animals.

THE EFFECT OF HUMAN ADIPOSE TISSUE-DERIVED MESENCHYMAL STEM CELLS ON AVASCULAR NECROSIS OF THE FEMORAL HEAD IN BEAGLE DOGS

Hyung Jun CHOI(최형준),Euna KWON,Ka Hee CHO,Jong Min KIM,Sang Young PARK,Min Kyong Hyon,Jeong Hwan CHE,Jeong Chan RA,Byeong Cheol KANG 한국실험동물학회 2011 한국실험동물학회 학술발표대회 논문집 Vol.2011 No.2

성역할 정체감이 체육교사와의 커뮤니케이션 인식에 미치는 영향

최형준(Choi, Hyung-Jun),한광령(Han, Kwang-Leong),임강영(Lim, Kang-Young) 한국체육과학회 2015 한국체육과학회지 Vol.24 No.6

The purpose of this study is to identify that the influence of the communication perception with PE teachers according to the sex role identity to the definition characteristics and to use it as a basic material which is helpful in the school PE site. With 400 students from two mixed middle schools in Seoul, it performed a questionnaire, analyzed 367 questionnaires among them, and used them in this study. The factor analysis and reliability analysis were performed for the collected questionnaires using SPSS 21.0 Version Program which is a statistic program. It also performed correlation analysis and multiple regression analysis and the induced results are as follows. There was a meaningful influence in the affect to the communication perception according to the sex role identity to clarity, consistency, distribution · validity, and interest · acceptance. In detail, the manhood of the sex role identity affected clarity, consistency, and interest · acceptance and the womanhood affected distribution · validity.

국소면적 근전도 신호 측정을 위한 PEDOT:PSS 기반 유연 마이크로전극 어레이

최형준(Hyung Jun Choi),김경민(Kyung Min Kim),양우진(Woo Jin Yang),박제원(Je Won Park),박동욱(Dong-Wook Park) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.11

In this work, we propose a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) based flexible branched electromyography (EMG) sensor for detecting small-area EMG signal from curved skin. By using semiconductor fabrication process, we fabricated a miniaturized 16-channel multielectrode sensor that can record small-area EMG. In general, platinum (Pt) and other metals were used as the electrode material of the EMG sensor. However, by substituting Pt with solution-processible PEDOT:PSS, the sensor arrays could be made cost-effectively while maintaining the impedance of the electrode. We also applied aluminum (Al) hard mask process instead of photoresist (PR) when etching the Parylene C encapsulation layers. This approach also makes the fabrication process simple by reducing the number of photomasks and increasing the process window of polymer dry etching. The sensor was fabricated on flexible and biocompatible Parylene C substrate so that it can detect the surface electromyography(sEMG) from curved skin surface. The recorded EMG signals were analyzed through fast fourier transform(FFT) and power spectral density (PSD) verifying that the flexible branched EMG sensor can record the multi-channel signals in small-area.

효율적인 원격 프로세스 검사점/재시작 프레임워크

최형준 ( Hyung Jun Choi ),김은성 ( Eunsung Kim ),정임영 ( Im Y. Jung ),염헌영 ( Heon Young Yeom ) 한국정보처리학회 2007 한국정보처리학회 학술대회논문집 Vol.14 No.2

병렬/분산 시스템의 신뢰도를 높이기 위해서는 결함 내성 기능을 갖추는 것이 필수적이다. 본 논문에서는 원격으로 프로세스에 대해 주기적으로 검사점을 만들고 예기치 않은 장애가 발생했을 경우 이를 신속히 가장 최근의 상태로 복원시켜 시스템의 안정성을 높일 수 있는 프레임워크에 대해서 연구한다.

Establishment of experimental avascular necrosis of the femoral head (AVN) in dogs

Hyung Jun Choi(최형준),Euna Kwon,Ka Hee Cho,Jong Min Kim,Sang Young Park,Min Kyong Hyon,Jeong Hwan Che,Byeong Cheol Kang 한국실험동물학회 2011 한국실험동물학회 학술발표대회 논문집 Vol.2011 No.2

DIAMETER base protocol을 위한 TLS over SCTP 구현

최형준(Choi hyung-jun),송주석(Song Joo-seok) 한국통신학회 2002 한국통신학회 학술대회논문집 Vol.2002 No.7

토양 내 미세플라스틱의 축적경로 및 분석기법 연구 동향

최형준 ( Hyung-jun Choi ),안진성 ( Jinsung An ),최석순 ( Suk Soon Choi ) 한국공업화학회 2020 공업화학 Vol.31 No.4

본 연구에서는 미세플라스틱의 토양 내 축적경로와 분포현황에 대해 살펴보고, 토양시료 내 미세플라스틱 분석기법을 요약 제시하였다. 토양으로부터 미세플라스틱을 분리해내는 밀도차 선별 및 방해물질 제거과정과 정성/정량분석 기법으로써 pyrolysis gas chromatography mass spectrometry, μ-Raman spectrometry, fourier transform infrared spectrometry와 microscope 방법의 기본원리 및 분석의 한계점에 대해 살펴보았다. 미세플라스틱 매개 유해물질(첨가제 및 흡착물질)의 분석을 위한 화학적 추출방법을 인체 경구 섭취경로에 대한 in vitro 생물학적접근성 평가법을 중심으로 조사하였다. 본 연구에서 제시한 토양 중 미세플라스틱 분석기법의 원리를 바탕으로 매질상태, 오염수준 및 시료수량 등을 고려한 합리적인 분석기법의 선정이 가능하리라 기대된다. In this study, the accumulation and distribution routes of microplastics in soil environment were examined, and their analytical methodologies were summarized. Density separation and removal process of inhibition materials were introduced for the separation of microplastics in soil and the basic principles and limitations of quantitative and qualitative analyses including pyrolysis gas chromatography mass spectrometry, μ-Raman spectrometry, fourier transform infrared spectrometry, and microscopes were investigated. Chemical extraction methods for the analysis of mediated hazardous substance (additives and sorbed matters) in microplastics were also discussed with focusing on in vitro bioaccessibility assay for the human oral exposure route. Based on the described methodologies for the analysis of microplastics in soil, it is expected that these methods enable to select appropriate analysis techniques in consideration of medium state, contamination level and sample quantity.

제1형 신경섬유종증 환자들에서 관찰된 망막미세혈관이상 소견

최형준(Hyung Jun Choi),윤정현(Jung Hyun Yoon),손병재(Byeong Jae Son),황수경(Su Kyeong Hwang),전보영(Bo Young Chun) 대한안과학회 2021 대한안과학회지 Vol.62 No.2

목적: 제1형 신경섬유종증 환자에서 관찰되는 망막미세혈관이상의 양상과 빈도를 알아보고자 하였다. 대상과 방법: 제1형 신경섬유종증 환자 61명과 전신질환 및 안과적 이상이 없는 대조군 61명의 안저촬영사진을 후향적으로 비교 분석하였다. 단순혈관굴곡, 나선상의 망막혈관, 모야모야형 패턴 양상으로 나타나는 망막미세혈관이상 유무를 확인하였고, 제1형 신경섬유종증에 대한 진단민감도, 진단특이도, 양성예측도, 음성예측도 및 진단정확도를 분석하였다. 결과: 환자군 중 19.7% (12명)에서 망막미세혈관이상이 있었으며, 대조군에서는 해당되는 경우가 없어서, 환자군과 대조군 간 망막미세혈관이상 유무는 의미있는 차이를 보였다(p=0.0003). 망막미세혈관이상을 보이는 환자 12명 중 11명은 단순혈관굴곡 양상이, 1명은 나선상의 망막혈관 양상이 관찰되었으며 1명은 2가지 소견 모두 나타내었다. 제1형 신경섬유종증에 대한 망막미세혈관이상의 진단민감도는 23.53%, 진단특이도는 100%, 양성예측도는 100%, 음성예측도는 61%였다. 진단정확도는 65.18%로, 리쉬결절의 진단정확도인 79.5%보다 다소 낮았으나, 신경섬유종의 진단정확도인 68.03%와 필적하는 진단정확도를 보였다. 결론: 제1형 신경섬유종증 환자군의 19.7%에서 망막미세혈관이상이 관찰되었으며 이 중 단순혈관굴곡 양상이 가장 많았다. 망막미세혈관이상이 대조군에서는 전혀 없었고, 진단정확도가 65.18%임을 고려하면 이는 제1형 신경섬유종증의 새로운 안과적 임상양상에 포함될 수 있을 것이다 Purpose: To evaluate the findings and frequencies of retinal microvascular abnormalities observed in patients with type 1 neurofibromatosis. Methods: Fundus photographs of 61 patients with type 1 neurofibromatosis and 61 controls without systemic disease or ophthalmic abnormalities were retrospectively compared and analyzed. The presence or absence of retinal microvascular abnormalities in the form of simple vascular tortuosity, corkscrew retinal vessels, and moyamoya-like patterns was confirmed, and the diagnostic sensitivity, diagnostic specificity, positive predictive value, negative predictive value, and diagnostic accuracy for type 1 neurofibromatosis were analyzed. Results: Retinal microvascular abnormalities were found in 19.7% (12 patients) of the patient group, There was no cases in the control group, thus. The difference between the patient group and the control group was significant (p = 0.0003). Of the 12 patients with abnormalities, 10 exhibited simple vascular tortuosity, one had corkscrew retinal vessels, and one exhibited both findings. The diagnostic sensitivity of retinal microvascular abnormalities for type 1 neurofibromatosis was 23.53%, the diagnostic specificity was 100%, the positive predictive value was 100%, and the negative predictive value was 61%. The diagnostic accuracy was 65.18%, which was slightly lower than the 79.5% diagnostic accuracy for the Lisch nodule, but the diagnostic accuracy was comparable to that of neurofibroma (68.03%). Conclusion: Retinal microvascular abnormalities were observed in 19.7% of type 1 neurofibromatosis patients, of which simple vascular tortuosity was the most common. Considering that retinal microvascular abnormalities were not observed at all in the control group, and the diagnostic accuracy was 65.18%, this type of abnormality could be included as a new ophthalmic clinical feature of type 1 neurofibromatosis.