일측성 광대뼈골절 환자에서 수평계와 자를 이용한 변위 교정의 간단한 파악법

이형석,이경석,김준식,김남균,Yi, Hyung-Suk,Lee, Kyung-Suk,Kim, Jun-Sik,Kim, Nam-Gyun 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.2

Purpose: The zygoma is a key element which composes the facial contour. Zygomatic fracture induces facial asymmetry. We use radiologic evaluation or inspections mainly for identification of symmetry after reduction depressed zygomatic fracture. But the disadvantages of such methods are time-consuming and complicated process. So we tried to develop a new testing method with a ruler and a level. Methods: In unilateral depressed zygomatic fracture patient, parallel to the patient's head to make sure lay horizontaly. Put the leg of a ruler on the malar eminence so that it is at the same distance from the facial midline. Then take the level of malar eminence as put the level above the ruler. This process was performed before and after the reduction. Results: We were able to fix with plate and screw after checking the results of reduction fast and easily. Good results were obtained at post-operative radiologic evaluation. Conclusion: We can easily get the ruler and level around life. This method is not only simple but also shorttime process compared with other method-radiologic evaluation or inspection. And the operator can explain the results to the patients easily and objectively. Authors obtained the good results with this new method, and would introduce it for another method of identifying the result of reduction in depressed zygomatic fractures.

귀밑샘에 생긴 다형선종의 수술적 치료로써의 제한적 국소절제술

이형석,김준식,김남균,이경석,이윤정,Yi, Hyung-Suk,Kim, Jun-Sik,Kim, Nam-Gyun,Lee, Kyung-Suk,Lee, Yoon-Jung 대한성형외과학회 2010 Archives of Plastic Surgery Vol.37 No.4

Purpose: Pleomorphic adenoma is the most common benign neoplasm in parotid gland. Superficial parotidectomy was usually used to remove the pleomorphic adenoma. But, this method has to remove tumor with normal parotid tissue. Authors did lumpectomy to remove pleomorphic adenoma in parotid gland, because pleomorphic adenoma is wrapped in a capsule as it grows. The purpose of this study is to evaluate the efficacy of lumpectomy as a treatment of pleomorphic adenoma in parotid gland. Method: From 2002 to 2008, 8 patients underwent the lumpectomy of the pleomorphic adenoma in parotid gland. Occurrence of the complications and recurrance were evaluated. Result: Patients were followed-up for a mean 45 months. There were no recurrance or no complication after lumpectomy. Conclusion: Authors suggest that the lumpectomy lead to decrese complications, recurrane and can be used as a procedure for the resection of pleomorphic adenoma in parotid gland.

전기차 응용을 위한 수직형 GaN 전력반도체 기술 동향

이형석,배성범,H.S. Lee,S.B. Bae 한국전자통신연구원 2023 전자통신동향분석 Vol.38 No.1

The increasing demand for ultra-high efficiency of compact power conversion systems for electric vehicle applications has brought GaN power semiconductors to the fore due to their low conduction losses and fast switching speed. In particular, the development of materials and core device processes contributed to remarkable results regarding the publication of vertical GaN power devices with high breakdown voltage. This paper reviews recent advances on GaN material technology and vertical GaN power device technology. The GaN material technology covers the latest technological trends and GaN epitaxial growth technology, while the vertical GaN power device technology examines diodes, Trench FETs, JFETs, and FinFETs and reviews the vertical GaN PiN diode technology developed by ETRI.

Sulfur Dioxide 가스 흡입 후 흰쥐 기관 점막에서 Laminin의 발현에 대한 연구

이형석,유연희,조석현,김경래,정호삼,Lee, Hyung-Seok,Yu, Yean-Hee,Cho, Seok-Hyun,Kim, Kyung-Rae,Chung, Ho-Sam 대한기관식도과학회 2000 大韓氣管食道科學會誌 Vol.6 No.1

Background and Objectives : The concentration of sulfur dioxide($SO_2$) gas in the ambient air appears increasing in the industry and urban area day by day. It was known that $SO_2$ is noxious gas. $SO_2$ can be irritating to the eyes, nose, throat, upper respiratory tract and skin. It produces sulfurous acid on contact with water and is extremely irritating to the nasopharynx and respiratory tract. Laminin is a family of extracellular matrix glycoproteins localized in the basement membrane that separates epithelial cells from the underlying stroma. The biological activities of laminin are to promote cell migration, wound healing, growth and differentiation. Meterials and Methods : The histologic changes and the expression of laminin in tracheal mucosa sacrificed at every weeks (to 7 weeks) after continued $SO_2$ exposure of 250ppm for 30 minutes a day were studied in rats. Results : Pathologic tissue was formed at the tracheal mucosa and the underlying tissue by the infiltration of monocytes and epithelium was transformed to the single cell layered epithelium above 5 weeks after exposure. At the 6 weeks after exposure, epithelial cells were partially lost and epithelial cell layer was transformed to be leaf-shaped. Submucosal tissue was transformed to be lymphatic tissue. An intense positive staining for laminin was found in apical cytoplasm and lateral surface of the normal epithelial cells and basement membrane but at the 5 and 6 weeks after exposure, laminin activity was decreased to the moderate activity. At the 7 weeks after exposure, laminin activity was decreased to the weak activity. Conclusion : Our finding suggests that $SO_2$ makes histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin. Longer duration of the exposure of $SO_2$ makes more histologic damage on the tracheal mucosa and decreases immunoreactivity for laminin.

Analysis of the Oxidative Stress-Related Transcriptome from Capsicum annuum L.

이형석,이상호,김호방,Nam Houn Lee,안정선 한국식물생명공학회 2010 식물생명공학회지 Vol.37 No.4

For the massive screening of the genes related to oxidative stress, a cDNA library was constructed from hot pepper (Capsicum annuum L. cv. Nockkwang) leaves treated with methyl viologen. From this library, 1,589 cDNA clones were sequenced from their 5' ends. The sequences were clustered into 1,252 unigenes comprised of 152 contigs and 1,100 singletons. Similarity search against NCBI protein database identified 1,005 ESTs (80.3%) as Known, 197 ESTs (15.7%) as Unknown, and 50 ESTs (3.99%) as No hit. In the ESTs, oxidative stress-related genes such as ascorbate peroxidase, catalase, and osmotin precursor were highly expressed. The cDNA microarray containing 1,252 unigenes was constructed and used to analyze their expression upon methyl viologen treatment. Analyses of the hybridization revealed that various stress-related genes such as peroxidase, tyrosine aminotransferase, and omega-6 fatty acid desaturase, were induced and some metabolism related genes such as aldolase and ketol-acid reductoisomerase, were repressed by methyl viologen treatment, respectively. The information from this study will be used for further study on the functional roles of oxidative stress-related genes and signaling network of oxidative stress in hot pepper.

다중 복호화 키들을 이용한 영상 워터마크 방법

이형석,서동환,조규보,Lee, Hyung-Seok,Seo, Dong-Hoan,Cho, Kyu-Bo 한국광학회 2008 한국광학회지 Vol.19 No.4

본 논문에서는 다중 복호화 키들을 이용한 영상 워터마크 방법을 제안하였다. 하나의 워터마크 영상에서 다중 복호화 키들을 이용하여 여러 개의 원 영상을 복원 할 수 있고 왈시 코드를 이용하여 복호화 과정에서 간단하게 사이드 로브를 제거한 복원 영상을 얻을 수 있는 장점을 갖고 있다. 삽입 과정에서 제로 패딩(zero-padding)된 원 영상들을 무작위 위상 영상들과 곱하여 푸리에 변환후 실수부를 취하여 부호화된 영상을 생성한다. 삽입 영상들은 확장된 부호화 위상 영상들을 새롭게 생성된 무작위 위상영상들과 곱한 후 이 영상들의 개수만큼 독립적으로 생성한 왈시 코드 영상들을 곱하여 생성하고 이 때 사용된 무작위 위상영상들에 동일한 왈시 코드 영상들을 곱하여 복호화 키 영상들로 사용한다. 스테고(stego) 영상은 삽입 영상들과 새로운 왈시 코드 영상이 곱하여진 커버(cover) 영상의 중첩에 의해 생성한다. 원 영상은 스테고 영상과 다중 복호화 키를 곱하여 비확산을 취한 후 역-푸리에 변환하여 복원할 수 있다. 컴퓨터 모의실험을 통하여 제안한 워터마크 방법의 적합성과 다중 복호화 키로 복원이 가능하고 영상에 잡음이 발생하더라도 원 영상의 복원이 가능함을 확인하였다. In this paper, we propose an image watermark method using multiple decoding keys. The advantages of this method are that the multiple original images are reconstructed by using multiple decoding keys in the same watermark image, and that the quality of reconstructed images is clearly enhanced based on the idea of Walsh code without any side lobe components in the decoding process. The zero-padded original images, multiplied with random-phase pattern to each other, are Fourier transformed. Encoded images are then obtained by taking the real-valued data from these Fourier transformed images. The embedding images are obtained by the product of independent Walsh codes, and these spreaded phase-encoded images which are multiplied with new random-phase images. Also we obtain the decoding keys by multiplying these random-phase images with the same Walsh code images used in the embedding images. A watermark image is then made from the linear superposition of the weighted embedding images and a cover image, which is multiplied with a new independent Walsh code. The original image is simply reconstructed by the inverse-Fourier transform of the despreaded image of the multiplication between the watermark image and the decoding key. Computer simulations demonstrate the efficiency of the proposed watermark method with multiple decoding keys and a good robustness to the external attacks such as cropping and compression.

악성 골 종양으로 오인된 급속 파괴형 고관절증 - 증례 보고 -

이형석,김정렬,Lee, Hyung-Seok,Kim, Jung-Ryul 대한근골격종양학회 2008 대한골관절종양학회지 Vol.14 No.2

급속 파괴형 고관절증(Rapidly destructive coxarthrosis)은 고관절에 발생하여 급속한 골파괴를 일으키며 현재까지 확실한 원인이 밝혀지지 않은 드문 질환이다. 임상적으로 극심한 고관절 통증과 파행을 나타내며, 방사선학적으로 수개월 내에 급속한 대퇴골두의 파괴를 일으키므로 류마토이드 관절염, 세균성 관절염, 신경병성 관절증 및 골종양과 감별을 요한다. 저자들은 우측 대퇴골두에 발생하여 4개월만에 급속한 골파괴성 병변을 보여 악성 골종양으로 오인되어 타 병원으로부터 전원 되었던 80세 여자 환자의 급속 파괴형 고관절증을 보인 증례를 경험하였기에 이를 문헌 고찰과 함께 보고하는 바이다. Rapid destructive hip osteoarthritis is a rare subset of osteoarthritis with rapid destruction of the hip joint within months of the onset of symptoms. The entity simulates rheumatoid arthritis, septic arthritis, neuropathy or malignant bone tumor. We report a case of rapidly destructive coxarthrosis of the right hip joint initially misdiagnosed as a malignant bone tumor at outside hospital in a 80-year-old woman.

기관피부누공에 대한 임상적 고찰

이형석,김현수,심봉택,태경,박철원,Lee, Hyung-Seok,Kim, Hyun-Soo,Shim, Bong-Taek,Tae, Kyung,Park, Chul-Won 대한기관식도과학회 1995 大韓氣管食道科學會誌 Vol.1 No.1

The tracheocutaneous fistula(TCF) may develop infrequently as a complication after tracheostomy. Prolonged tracheostomy tube dependence increases the risk of TCF developing, and in growth of stratified squamous epithelium lines the furrow connecting the tracheal mucosa and the skin, accounting for persistence of the fistulous tract. Such fistulas are a nuisance and create nursing and social problems including poor hygiene, aspiration, difficulty with speech, and depletion of pulmonary reserve. Surgical closure has generally been successful by primary closure, fistulectomy with primary closure, and closure by secondary intention following excision of the tracheocutaneous fistula. No large series compares the efficacy of these techniques and each has its own merits. Recent literature has purposed to minimizing complications. For ten years, from January 1985 to December 1994, the authors experienced 25 cases of TCF which were analyzed in respect to incidence and interval of cannulation, duration between decanulation and fistular closure, precedent disease, closure methods, and complications of TCF repair.

Dr. Speech Science를 이용한 정상 및 후두질환 환자의 음향분석

이형석,태경,장경진,김경우,김경래,박철원,Lee, Hyung-Seok,Tae, Kyung,Jang, Kyung-Jin,Kim, Kyung-Woo,Kim, Kyung-Rae,Park, Chul-Won 대한후두음성언어의학회 1997 대한후두음성언어의학회지 Vol.8 No.2

Background : For example, aerodynamic study, vibratory study, acoustic study, neuro-muscular test and psychoacoustic evaluation, a number of objective methods are now available for assessing pathologic voice change. They help to differentiate pathologic condition from normal condition and to monitor pathologic and aging change. These laboratory analyses are used commonly to monitor speech therapy and to follow a patient's recovery after surgery. Objectives : We investigated the values of jitter, shimmer and NNE of normal person and hoarseness patients in Korea. The values of Jitter and shimmer might be meaningful parameters distinguishing pathologic vibration from normal and recovery after surgery. Materials and Methods : Statistical significance between normal control and 48 subjects taken microlaryngeal surgery were compared with Dr. speech science program that is computerized system for acoustic analysis of voice production employed to determine vocal characteristics of pitch perturbation(jitter) and amplitude perturbation(shimmer). Results : The mean normal values of jitter and shimmer were 0.226${\pm}$0.110(%), 2.200${\pm}$0.421(%) in male and 0.164${\pm}$0.060(%), 2.063 ${\pm}$0.575(%) in female. In patients with vocal nodule, the preoperative and postoperative values of jitter and shimmer were valueless. In patients with vocal polyps, the preoperative and postoperative values of jitter and shimmer were valuable. Conclusion : Dr. speech science program was effective to monitor laryngeal disease and aging changes.

백서 기관 점막의$SO_2$ 노출 후 회복과정의 조직학적 관찰 및 laminin의 발현에 관한 연구

이형석,태경,조석현,한장희,정진석,Lee, Hyung-Seok,Tae, Kyung,Cho, Seok-Hyun,Han, Jang-Hee,Jeong, Jin-Suck 대한기관식도과학회 2002 大韓氣管食道科學會誌 Vol.8 No.1

Background and Objectives : Sulfur dioxide gas is one of the major airborne Pollutants noxious to human in industrialized countries. The most vulnerable areas in the human respiratory system were the trachea and main bronchi and a gradient of decreasing damage was observed in the peripheral tracheobronchial tree. Induced functional alteration was increased mucosal permeability, and morphological changes were epithelial sloughing, intracellular edema, mitochondrial swelling, widened intercellular spaces, and ciliary cytoplamic extrusions. The laminins are a family of extracellular matrix glycoproteins localized in the basement membrane. Their primary role is cell-matrix attachment, but many additional biologic activities, including Promoting cell growth and migration, tumor growth and metastasis, wound repair, and graft survival, have been demonstrated. Materials and Methods : Histologic changes and expression of laminin in tracheal mucosa sacrificed at 1 day, 2 day, 3 day, 1 week, 2 weeks, and 3 weeks after continued SO2 exposure of 250 ppm for 30 minutes a day(to 7week) were studied in rats. In this study, mild immune reaction for laminin was noted at the apical cytoplasm of epithelial cells and basement membrane one day after a 7 week $SO_2$ exposure. The cilia and nucleoi of epithelial cells were normal and no immune reaction was noted in Goblet cells. The lamina propria of the tracheal tissue was infiltrated by monocytes and lymphocytes. Results : At 24 hours after exposure, all tracheal cells except Goblet cells revealed a mild immune reaction for laminin. No immune reactions were noted in the basement membrane. At 72 hours after exposure, mild or moderate immune reactions for laminin was seen in the tracheal cell cytoplasm. Irregular faint immune reaction for laminin was noted in the basement membrane. At 1 week after exposure, strong immune reaction for laminin was detected over all tracheal cells, and the basement membrane was seen clearly. At 2~3 weeks after exposure, strong immune reaction for laminin was seen in all tracheal epithelial cells except Goblet cells and a mild immune reaction was partly revealed in the basement membrane. Conclusion : Our study suggests that 502 produces histologic damage on the tracheal mucosa. Longer duration after exposure of $SO_2$ makes more progressive healing on the tracheal mucosa and increased immunoreactivity for laminin.