Emission of SiOx Nanowires Resulting from Pressure Changes in a Closed System Comparable to a Tungsten Electron Gun at a High Voltage

정택균,류민,이지운,현승균,나한길,최경환,진창현 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.7

SiOx nanowire emission with changes in the vapor pressure of Sn metal results in a screw motion of SiOx nanowires in a closed system consisting of Sn and SiOx. A convoluted flouncing-off process is elucidated here, in which the elementary particles are not electrons, but nanowires. In order to understand the unprecedented synthetic phenomena, the system that emits SiOx nanowires is compared with tungsten electron gun by comparing the component, functionalization, and theoretical background of both the techniques. The results so obtained, which are the first of its kind, open the way not only to produce three-dimensional micro- and nano-structures from one dimensional nanostructures without requiring any additional artificial manipulation process but also to focus them onto a desired small region for elaborate deposition.

하악 제1, 2대구치 단일 임플란트의 생존율에 관한 연구

정택균,팽준영,조진현,이상한,Jung, Taek-Gyun,Paeng, Joon-Young,Cho, Jin-Hyun,Lee, Sang-Han 대한치과보철학회 2013 대한치과보철학회지 Vol.51 No.4

연구 목적: 치과 임플란트가 소개된 이후로 단일 치아 상실에 따른 임플란트 수복에 관한 성공적인 연구 결과들이 보고되고 임상적으로도 널리 사용되고 있다. 구강내의 다양한 부위에 따른 연구들이 있어 왔으나, 교합력이 강한 구치부 특히 하악 구치부에서 단일 임플란트에 관한 연구가 필요할 것이다. 본 연구는 하악의 제1대구치와 제2대 구치 부위에 식립된 단일 임플란트의 생존율에 관해 연구, 분석하였다. 연구 대상 및 방법: 2002년부터 2009년까지 대구광역시 소재의 7개 치과의원에서, 하악 제1, 2대구치에 단일 임플란트 치료를 받은 환자 284명에게 식립된 308개의 임플란트를 대상으로 하였다. 하악 제1대구치에 168개의 임플란트가 식립되었고, 하악 제2대구치에 140개의 임플란트가 식립되었다. 이들 임플란트는 식립위치, 환자의 성별, 연령, 임플란트의 직경 및 길이에 따라 분석하였다. 결과:하악 제1대구치에서는 4개의 임플란트가, 하악 제2대구치에서는 10개의 임플란트가 실패하였다. 하악 제1대구치에서는 97.6%, 하악 제2대구치에서는 92.9%의 성공률을 나타내었다. 환자의 연령, 성별, 식립방법, 임플란트의 직경 등에 따른 차이는 관찰할 수 없었다. 결론: 하악 제1대구치 단일 임플란트의 생존율은 하악 제2대구치 단일 임플란트의 생존율보다 높게 나타났다. 이는 하악 제2대구치 부위의 골질이 좋지 않고, 하악의 해부학적인 구조로 인해 하악 제2대구치 부위에 과도한 교합력이 가해질 우려가 있기 때문이라 생각된다. Purpose: After the introduction of concept of osteointegration, dental implantology have been successful procedure in the dental field. Recently, it has shown successful results when used to restore single tooth missing. Considering the difference in bone quality of the mandible and maxilla, and the increased occlusal force in the posterior region, the success rates in each region may be different. In this study, success rates of single implants placed in the mandibular first and second molar areas were analyzed. Materials and methods: The subjects were patients (284 patients, 308 implants) who had been operated with single implant installation from 2002 to 2009 in seven dental clinics in Daegu city. One hundred sixty eight implants were placed in the mandibular 1st molar and 140 implants were placed in the mandibular 2nd molar. They were analyzed according to implant site, age, sex, length and diameter. Results: The survival rates of single implant of this study were 97.6% in the mandibular 1st molar and 92.9% in the mandibular 2nd molar. In the mandibular 1st molar, 4 implants were failed. In the mandibular, 2nd molar, 10 implants were failed. Conclusion: The restoration of the mandibular 1st molar using single implant was found to be clinically acceptable treatment and showed higher survival rate than mandibular 2nd molar single implant. Single implant in mandibular 2nd molar needs careful consideration of poor bone quality, risk of overloading and anatomical structure of the mandible.

당뇨병성 신증 환자에서 저분자량 헤파린 Dalteparin Sodium 사용 중 발생한 후복막강 혈종 1예

정택균,정균호,박병석,마성권,김수완,김남호,최기철 대한내과학회 2003 대한내과학회지 Vol.64 No.3

신대체 요법의 유무에 관계없이 신기능 장애가 있는 환자에서 항응고 치료로 저분자량 헤파린 (dateparin, enoxaparin 등)을 사용할 경우에는 제제에 관계없이 심한 출혈의 위험성이 높아질 수 있기 때문에 세심한 주의를 요한다. 6~8일 이상 투여하는 것은 삼가고 심각한 출혈을 일으킬 수 있음을 항상 주지하여야 하며 , 특히 항응고 치료 과정 중에 치료 전 없었던 옆구리, 서혜부, 하요부 및 하지의 통증 , 빈혈, 저혈압 등이발생하였을 때 후복막강 혈종의 가능성을 항상 고려하여야 할 것이다. Retroperitoneal Hematoma is a rare intraabdominal bleeding occurring in patients with low-molecular weight heparin anti-coagulant therapy. we report a case of dalteparin sodium-associated retroperitoneal hematoma in a 70-year-old man with diabetic nephropathy with review of this condition in the literature. He had been suffered from type 2 diabetes mellitus and hypertension for 15 years. In July 2002, he was admitted to our hospital because of unstable angina and left pleural effusion. He was treated with dalteparin sodium and aspirin for unstable angina. On the second hospital day, he was referred to division of nephrology for diabetic nephropathy. Laboratory data on admission included white blood cell count of 4,500/㎣, hemoglobin 9.6 g/dL, platelet count 294,000/㎣, BUN 58.1 mg/dL, serum creatinine 4.1 mg/dL, blood glucose 178 mg/dL, hemoglobin A1c5.9T, PT 13.9 sec (INR: 1.09), and aPTT 50 sec, On days 6 through 8, he had lower back pain, lower extremity pain and neuropathy, anemia and hypotension. Abdominal ultrasound showed 6×6 cm-sized well marginated mixed echogenic lesion in psoas muscle and fluid collection in retroperitoneal cavity. Magnetic resonance imaging (MRI) showed increased signal intensity and thickening of the right psoas muscle including 4.7×2.3×21 cm-sized cytic lesion and 6.2×5.3×3.7 cm-sized cystic lesion on the lateral portion of right psoas muscle in T2-weighted images. Percutaneous drainage of cystic lesion was performed by right lateral approach. Hemodialysis was begun without heparinization. Abdominal CT showed 5.5×5 cm-sized high attenuated lesion in right psoas muscle and 5×3 cm, 3×2 cm, 4.5×2.5 cm, 4×2.5 cm-sized heterogeneous, slightly high attenuated lesions in the right lower abdomen and cul-de-sac in the scans with no enhancement. He was treated by conservative therapy. He recovered gradually. Patients with kidney diseases receiving low molecular weight heparin (dalteparin, enoxaparin, etc) should be closely monitored to prevent serious bleeding complications. The possibility of retroperitoneal hematoma should be considered, whenever symptoms including lower back pain, inguinal pain, leg pain, anemia, or hypotension occurred during the lower molecular weight heparin anticoagulant therapy. To our knowledge, this is the first reported case of retroperitoneal hematoma in a patient during dalteparin sodium (Fragmin^??) anticoagulant therapy. (Korean J Med 64:322-327, 2003)

당뇨병성 신증 환자에서 저분자량 헤파린 Dalteparin Sodium 사용 중 발생한 후복막강 혈종 1예

정택균,정균호,박병석,마성권,김수완,김남호,최기철 대한내과학회 2003 대한내과학회지 Vol.65 No.2

Comparison of Structural and Optical Properties of TeO2 Nanostructures Synthesized Using Various Substrate Conditions

정택균,류민,이지운,현승균,나한길,진창현 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.6

Several TeO2 low-dimensional nanostructures were prepared by thermal evaporation using four substrate conditions:(1) a bare substrate, (2) a scratched substrate, (3) a Au-catalyst-assisted substrate, and (4) a multi-walled carbonnanotube (MWCNT)-assisted substrate. Scanning electron microscopy and transmission electron microscopyanalysis reveals that the morphologies of the nanostructures synthesized using these methods gradually changedfrom nanoparticles to ultra-thin nanowires with single tetragonal-type TeO2. Photoluminescence (PL) spectrareveal that the PL intensities of the TeO2 nanomaterials obtained using methods (1) and (2) are slightly increased,whereas the intensities of the TeO2 nanostructures obtained using methods (3) and (4) differ significantly dependingon the initial substrate conditions. The emission peak is also blue-shifted from ~440 nm to ~430 nm for thescratched surface condition due to an excitonic transition. The increase in the blue emission for the MWCNTassistedcondition is attributed to the degree and type of excitons and defects in the TeO2 nanostructures.

Metastable TiNbSn 합금을 이용한 Advanced Hip Joint Stem의 개발 (초)

정택균,( Tadasu Abumiya ),( Noya Masahashi ),( Shuji Hanada ),김목순 대한금속ㆍ재료학회 2009 대한금속재료학회 학술대회 개요집 Vol.2009 No.1

Tensile Properties of Copper-Nickel Fine Clad Prepared by Surface Activation Bonding and Subsequent Heat Treatment

정택균,김경훈,Dong-Woo Joh,Kyu-Young Heo,이효수,Sung-Chul Lim,권혁천 대한금속·재료학회 2013 ELECTRONIC MATERIALS LETTERS Vol.9 No.6

The tensile properties of a Cu/Ni fine clad prepared by surface activation bonding were investigated as a function of the heat-treatment temperature and the diffusion layer thickness. A negligibly thin diffusion layer, less than 5 nm in thickness, was formed in the as-bonded Cu/Ni fine clad, but the thickness increased significantly after subsequent heat treatments. As the temperature increased, the yield strength and tensile strength increased; this was attributable to the microstructural features of the raw materials. The yield strength values calculated using a rule-of-mixture model were lower than those determined experimentally. We attributed this difference in the values to the diffusion layer and friction at the interfaces between the various phases. The friction strength of the copper/nickel foils was higher than those of the copper foil/diffusion layer and the nickel foil/diffusion layer. The results of the study suggested that the tensile properties of the Cu/Ni fine clad were affected by the following: (1)the volume fraction of the raw materials and their individual strengths, (2) the volume fraction of the diffusion layer and its strength, and (3) the friction strength at the interfaces of the various phases.

지속성 외래 복막투석 환자에서 발생한 당뇨병성 근육 경색증

정택균 ( Taek Kyun Jeong ),이연경 ( Youn Kyoung Lee ),정균호 ( Gyun Ho Jeong ),박병석 ( Byong Seok Park ),마성권 ( Seong Kwon Ma ),김수완 ( Soo Wan Kim ),김남호 ( Nam Ho Kim ),최기철 ( Ki Chul Choi ) 대한신장학회 2003 Kidney Research and Clinical Practice Vol.22 No.1

Diabetic muscle infarction (DMI) is a rare condition occurring in subjects with long-standing complicated diabetes mellitus. We report DMI in a 65-vear-old man with type 2 diabetes mellitus undergoing continous ambulatory peritoneal dialysis (CAPD) with review of this condition in the literature. He had been suffered from type 2 diabetes mellitus for 21 years. In 1997, he reached end-stage renal disease and had received on renal replacement therapy with CAPD since then. In June 2002, he presented with sudden and spontaneous onset of severe pain in the right thigh region. He was afebrile, and the right thigh was swollen and tender but not erythematous. Laboratory data on admission included white blood cell count of 15,800/㎣, hemoglobin 9.0g/dL, platelet count 264,000/㎣, BUN 102.3mg/dL, serum creatinine 9.9 mg/dL, fasting blood glucose 85 mg/dL, postprandial 2 hours blood glucose 162 mg/dL, hemoglobin AIC 5.84%, ESR 125 mm/h (it was 52 mm/h one month earilier), CRP 18.9 mg/dL, and normal levels of creatinine kinase. Magnetic resonance imaging (MRI) showed asymmetry of the muscle in T1-weighted images and increased signal intensity involving the medial portion of right thigh (adductor longus, adductor magnus, vastus intermedius muscle, etc) in T2-weighted images with no contrast enhancement. Radioistope venography of the ileo-femoral veins was was normal, excluding deep venous thrombosis as a cause. The right thigh was explored surgically and a biopsy taken from the vastus intermedius muscle was consistent with chronically inflammed scar tissue with no evidence of malignancy. A biopsy taken from the vastus intermedius muscle showed hemorrhagic necrosis of skeletal muscle, with lymphcytic infiltration. Most of the blood vessels appeared normal. The swelling resolved spontaneously following a few weeks of bedrest and analgesia. To our knowledge, this is the first reported case of DMI in patients undergoing renal replacement therapy in Korea.

FCAW를 이용한 이종금속재료 용접시 보호가스 혼합량에 따른 용접부 기계적 특성

엄민혁,정택균,현승균 대한용접·접합학회 2019 대한용접학회 특별강연 및 학술발표대회 개요집 Vol.2019 No.5

포스터 전시 발표 : 신장 ; Stop Dialysate Flow Method을 이용한 투석 적절도 평가의 유용성

정균호,정택균,박병석,마성권,김수완,김남호,최기철 대한내과학회 2002 대한내과학회 추계학술대회 Vol.63 No.-