Endovascular Treatment to Stop Life-threatening Bleeding from Branches of the External Carotid Artery in Patients with Traumatic Maxillofacial Fracture

OBJECTIVE: The purpose of this study was to report our preliminary experience with endovascular treatment (EVT) for life-threatening bleeding from branches of the external carotid artery (ECA) in patients with traumatic maxillofacial fractures. MATERIALS AND METHODS: A total of 12 patients seen between March 2010 and December 2014 were included in this study. All subjects met the following criteria: 1) presence of maxillofacial fracture; 2) continuous blood loss from oronasal bleeding; and 3) EVT to stop bleeding. Various clinical factors were recorded for each patient and the correlations between those factors and clinical outcome (Glasgow Outcome Scale, GOS) were evaluated. RESULTS: Four patients were injured in traffic accidents, five in falls, and three by assaults. Mean initial Glasgow Coma Scale (GCS) was 6.9 ± 2.1 and the lowest hemoglobin measured was mean 6.3 ± 0.9 g/dL. GOS at discharge was 4 in five patients, 3 in three patients, and 1 (death) in four patients. GOS on follow-up (mean 13.7 months) was 5 in two patients, 4 in three patients, and 3 in three patients. Initial GCS (p = 0.016), lowest systolic blood pressure (p = 0.011), and lowest body temperature (p = 0.012) showed a significant positive correlation with good clinical outcomes. The number of units of red blood cells transfused (p = 0.030), the number of units of fresh frozen plasma transfused (p = 0.013), and the time from arrival to groin puncture (p < 0.001) showed significant negative correlation with good clinical outcomes. CONCLUSION: It might be suggested that rapid transition to EVT could be preferable to struggling with other rescue strategies to stop life-threatening bleeding from branches of the ECA in patients with traumatic maxillofacial fractures.ope

Neurological Deterioration after Decompressive Suboccipital Craniectomy in a Patient with a Brainstem-compressing Thrombosed Giant Aneurysm of the Vertebral Artery

We experienced a case of neurological deterioration after decompressive suboccipital craniectomy (DSC) in a patient with a brainstem-compressing thrombosed giant aneurysm of the vertebral artery (VA). A 60-year-old male harboring a thrombosed giant aneurysm (about 4 cm) of the right vertebral artery presented with quadriparesis. We treated the aneurysm by endovascular coil trapping of the right VA and expected the aneurysm to shrink slowly. After 7 days, however, he suffered aggravated symptoms as his aneurysm increased in size due to internal thrombosis. The medulla compression was aggravated, and so we performed DSC with C1 laminectomy. After the third post-operative day, unfortunately, his neurologic symptoms were more aggravated than in the pre-DSC state. Despite of conservative treatment, neurological symptoms did not improve, and microsurgical aneurysmectomy was performed for the medulla decompression. Unfortunately, the post-operative recovery was not as good as anticipated. DSC should not be used to release the brainstem when treating a brainstem-compressing thrombosed giant aneurysm of the VA.ope

Preliminary Experience with Vascular Plugs for Parent Artery Occlusion of the Carotid or Vertebral Arteries

OBJECTIVE: The purpose of this study was to report the authors' preliminary experience using the Amplatzer Vascular Plug (AVP) (St. Jude Medical, Plymouth, MN, USA) for parent artery occlusion of the internal carotid artery (ICA) or vertebral artery (VA). MATERIALS AND METHODS: Between September 2008 and December 2015, we performed 52 therapeutic parent artery occlusions (PAOs) by an endovascular technique. Among them, 10 patients underwent PAO of the carotid or vertebral arteries using AVPs. Clinical and radiographic data of these patients were retrospectively reviewed. RESULTS: The devices were used for VA dissection that presented with subarachnoid hemorrhage (SAH) in five patients, traumatic arteriovenous fistula (AVF) in two patients, spontaneous AVF in one patient, recurrence of carotid-cavernous fistula (CCF) in one patient, and symptomatic unruptured giant ICA aneurysm in one patient. The devices were used in conjunction with detachable and/or pushable coils and in the extracranial segments of the ICA or VA. Complete occlusion of the parent artery was achieved in all patients. There was one intra-procedural rupture of the VA dissection during coiling prior to using the device. CONCLUSION: Results from the current series suggest that the AVP might be used for therapeutic PAO in the extracranial segments of the ICA or VA.ope

Delays in Intracerebral Hemorrhage Management Is Associated with Hematoma Expansion and Worse Outcomes: Changes in COVID-19 Era

Purpose: The coronavirus disease 2019 (COVID-19) pandemic disrupted the emergency medical care system worldwide. We analyzed the changes in the management of intracerebral hemorrhage (ICH) and compared the pre-COVID-19 and COVID-19 eras. Materials and methods: From March to October of the COVID-19 era (2020), 83 consecutive patients with ICH were admitted to four comprehensive stroke centers. We retrospectively reviewed the data of patients and compared the treatment workflow metrics, treatment modalities, and clinical outcomes with the patients admitted during the same period of pre-COVID-19 era (2017-2019). Results: Three hundred thirty-eight patients (83 in COVID-19 era and 255 in pre-COVID-19 era) were included in this study. Symptom onset/detection-to-door time [COVID-19; 56.0 min (34.0-106.0), pre-COVID-19; 40.0 min (27.0-98.0), p=0.016] and median door to-intensive treatment time differed between the two groups [COVID-19; 349.0 min (177.0-560.0), pre-COVID-19; 184.0 min (134.0-271.0), p<0.001]. Hematoma expansion was detected more significantly in the COVID-19 era (39.8% vs. 22.1%, p=0.002). At 3-month follow-up, clinical outcomes of patients were worse in the COVID-19 era (Good modified Rankin Scale; 33.7% in COVID19, 46.7% in pre-COVID-19, p=0.039). Conclusion: During the COVID-19 era, delays in management of ICH was associated with hematoma expansion and worse outcomes.ope

파라메트릭 모델링을 이용한 구두골의 설계와 그 방법

학위논문(석사)--서울대학교 대학원 :기계항공공학부,2001.Maste

특성화고등학교 졸업예정자의 취업능력과 개인특성, 가정특성 및 학교만족 변인과의 관계

학위논문 (석사)-- 서울대학교 대학원 : 농산업교육과, 2016. 2. 나승일.이 연구의 목적은 특성화고등학교 졸업예정자의 취업능력과 개인특성, 가정특성 및 학교만족 변인과의 관계를 구명하는데 있었다. 이를 위한 구체적인 연구목표는 특성화고등학교 졸업예정자의 취업능력 수준을 구명하고, 취업능력 수준과 개인특성, 가정특성 및 학교만족 변인 간의 관계를 구명하는데 있었다. 이 연구의 모집단은 2015년 7월 1일을 기준으로 특성화고등학교에 재학 중인 졸업예정자인 3학년 학생들로서, 총 459개교 111,773명이었다. 표본은 유층화비율표집을 통해 1,021명을 선정하였다. 자료분석은 SPSS for window 22.0을 이용하여 빈도와 백분율, 평균과 표준편차 등의 기술통계와 t검증, 중다회귀분석 및 AMOS를 활용하여 확인적요인분석을 실시하였다. 통계적 유의수준은 0.05 이였다. 자료수집을 위한 조사도구는 질문지를 사용하였으며, 질문지는 취업능력 측정도구, 개인특성 측정도구, 가정특성 측정도구, 학교만족 측정도구로 구성되었다. 취업능력 측정도구는 취업능력을 구성하는 직업 및 구직능력 8문항, 직업 및 구직능력 6문항, 직업 및 구직자신감 4문항, 노동시장 수요인식 3문항으로 총 21개 문항으로 Likert 5점 척도로 구성되었다. 자료수집은 2015년 8월 24일부터 9월 16일까지 우편조사를 통해 이루어졌으며, 총 1,120부를 배부하여 1,085부가 회수되었다(회수율 96.8%). 이 중 무응답하거나 불성실하게 응답한 설문지를 제외한 972부의 자료를 최종 분석에 사용하였다. 이 연구의 결과는 첫째, 개인특성, 가정특성, 학교만족 변인 수준은 학교성적이 4.03등급 수준으로 나타났고, 진로결정자기효능감은 보통 수준으로 나타났다. 가정특성 변인은 가구소득이 중간 수준으로 나타났고, 가정의 진로지지는 보통수준으로 나타났다. 학교만족 변인의 경우 수준이 대부분 보통 수준이었고, 학교 생활만족, 학교 진로지도 참여 만족, 학교 취업지원프로그램 만족 순으로 나타났다. 둘째, 특성화고등학교 졸업예정자의 취업능력 수준은 보통 수준으로 나타났다. 취업능력의 하위요인 중 직업 및 구직능력 수준이 가장 높게 나타났다. 또한, 노동시장 수요인식이 가장 낮게 나타났다. 또한, 취업능력의 수준차이는 성별에 따라, 학교성적, 자격증 수, 진로결정자기효능감, 희망전공 일치여부, 가구소득 수준, 가정의 진로지지, 학교생활만족, 학교 진로지도 참여 만족, 학교 취업지원프로그램 만족에 따라 나타났다. 하지만, 아르바이트를 경험 한 학생은 하지 않은 학생에 비해 취업능력에 있어 유의미한 차이가 나타나지 않았다. 셋째, 특성화고등학교 졸업예정자의 취업능력과 각 변인들과의 상관관계를 살펴보면 진로결정자기효능감은 높은 정적상관이(r=0.725), 학교생활만족은 중간 정적상관이(r=0.492), 학교진로지도 참여만족은 중간정적상관이(r=0.487), 가족의 진로지지는 중간 정적상관이(r=0.462), 학교 취업지원프로그램 만족은 중간 정적상관(r=0.425), 학교성적은 낮은 정적상관이(r=0.287), 가구소득 수준은 매우낮은 정적상관이(r=0.172), 자격증 수는 매우낮은 정적상관(r=0.165)이 나타났다. 넷째, 특성화고등학교 졸업예정자의 취업능력에 통계적으로 유의미한 영향력을 미치는 변인들은 진로결정자기효능감(β=0.541), 학교생활만족(β=0.112), 학교성적(β=0.093),가족의 진로지지(β=0.078), 희망직업 전공일치여부(β=0.071), 학교진로지도 참여만족(β=0.069), 성별(β=0.050)이였다. 이 연구의 결론은 첫째, 특성화고등학교 졸업예정자의 학교성적, 진로결정자기효능감은 보통수준이다. 또한, 가족 구성원이 학생들의 진로결정 및 직업탐색에 미치는 영향은 보통수준이이며, 학교생활에 만족하는 정도, 학교의 진로지도 활동에 대한 만족정도, 학교에서 학생들의 취업지원을 위해 구성한 프로그램 만족정도 모두 보통수준이다. 둘째, 취업능력 수준에 있어 개인의 특성, 가정의 특성, 학교생활 및 학교의 취업관련 다양한 프로그램에 따라 차이가 있다고 할 수 있다. 셋째, 취업능력은 개인특성, 가정특성 및 학교만족에 해당하는 변인들 중 아르바이트 경험을 제외하고 모두 정적 관계가 있다. 특히, 진로결정자기효능감이 정적 관계가 높게 나타났고, 이는 학생이 취업능력 향상에 있어 주요한 변인이 됨을 확인할 수 있다. 넷째, 취업능력을 설명하기 위하여 설정한 변인들은 비교적 취업능력을 잘 설명하고 있다. 이 연구의 제언은 다음과 같다. 첫째, 특성화고등학교 졸업예정자들에게 재학 중 다양한 직업과 관련된 경험을 할 수 있도록 많은 기회를 제공해야 한다. 둘째, 특성화고등학교 졸업예정자들이 전공과 관련된 희망하는 직업을 파악할 수 있도록 학부모 및 학교의 관심과 지도가 필요하다. 셋째, 학교 생활 만족 수준이 취업에 대한 기대수준에 영향을 미치기 때문에, 학생들이 취업에 대한 기대수준을 적절히 조절할 수 있도록 방안을 모색해야 한다. 넷째, 졸업예정자의 취업능력에 영향을 미치는 관련변인 중 진로결정자기효능감이 가장 높게 영향을 미치는 것으로 나타남에 따라 학생들이 직업을 탐색하고 진로를 결정하기 위한 준비, 계획, 실행 등의 신념을 가질 수 있도록 가정과 학교에서의 관심과 지도가 필요하다. 다섯째, 가족이 학생들의 취업처를 선택해주는 결정권자의 역할만을 하는 것이 아닌, 취업능력 개발 및 향상과 관련하여 일에 대한 경험을 함께하거나 직업에 대한 다양한 취업정보 제공 및 진로에 대한 상담자 역할을 해야 한다. 여섯째, 교사들의 올바르고 정확한 취업처 정보를 학생들에게 제공할 필요가 있다. 또한, 또래집단 간 서로 도움이 될 수 있는 취업 정보를 주고 받을 수 있도록 학교차원의 환경조성이 필요하다.I. 서론 1 1. 연구의 필요성 1 2. 연구의 목적 3 3. 연구 문제 4 4. 용어의 정의 5 II. 이론적 배경 8 1. 특성화고등학교의 발달과 취업지도 8 2. 취업능력의 개념과 선행연구 14 3. 취업능력과 개인특성, 가정특성 및 학교만족 변인과의 관계 38 III. 연구방법 57 1. 연구모형 57 2. 연구대상 58 3. 조사도구 60 4. 자료수집 65 5. 자료분석 65 Ⅳ. 연구결과 68 1. 특성화고등학교 졸업예정자의 특성 68 2. 특성화고등학교 졸업예정자의 취업능력 수준과 차이 71 3. 취업능력과 개인특성, 가정특성 및 학교만족 변인과의 관계 78 4. 취업능력에 대한 개인특성, 가정특성 및 학교만족 변인의 설명력 80 5. 연구결과에 대한 논의 91 Ⅴ. 요약, 결론 및 제언 97 1. 요약 97 2. 결론 99 3. 제언 100 참고문헌 102 부록 116 Abstract 135Maste

Present and future of guided tissue regeneration

학위논문 (석사)-- 서울대학교 대학원 : 치의학과, 2011.2. 김태일.Maste

액정 디스플레이 블랙 매트릭스 용 프탈로시아닌 염료 및

학위논문 (박사)-- 서울대학교 대학원 : 재료공학부, 2014. 2. 김재필.The most frequently used material for black matrix is carbon black, which has advantages of high thermal stability and high light absorption. However, black matrices fabricated with carbon black have high dielectric constants, causing electrical signal transduction errors on thin film transistors. To avoid this problem, organic pigment BMs with a low dielectric constant can be used, but their low spectral properties due to the lower molar extinction coefficient of organic pigments have limited their applications. In general, dyes have much lower dielectric constants compared with carbon black, and show much higher light absorption properties than organic pigments. Thus, if dyes are used for the manufacture of the black matrix, the high dielectric constant and low light absorption of conventional black matrices can be overcome. On the other hand, dyes generally have low thermal stability compared to carbon black and organic pigments. Therefore, the dyes for black matrix need to be structurally stable. They also should have good solubility in industrial solvents, such as propylene glycol methyl ether acetate and cyclohexanone. In addition, as dyes generally have sharp absorption ranges, dye-based black matrices need to be fabricated by mixing red, green and blue dyes, or cyan, magenta and yellow dyes, as well as by mixing dyes and carbon black.. In this study, green metal-free phthalocyanine dyes with high thermal stability and high solubility were designed. Three phthalocyanine dyes were synthesized by introducing substituents including alkyl or alkoxy groups to the peripheral position of the phthalocyanine rings, and their spectral properties, solubilities and thermal stabilities were measured. In addition, dye-based black matrices were fabricated and their optical and dielectric properties were examined. The metal-free phthalocyanine dyes showed the increase in solubility due to bulky functional substituents at the peripheral positions of them. In addition, the dyes including terminal alkoxy groups showed suitable thermal stability for commercial use due to terminal alkoxy groups are stable at postbaking temperature. Since all dyes had high molar extinction coefficients, dye-based black matrices absorbed light in the visible region with the small amounts of the dyes. The dielectric constants of the black matrices containing more than 30wt% of dyes were significantly lower than that of the black matrix prepared with carbon black only. Furthermore, greenish zinc phthalocyanine dyes and reddish perylene dyes were synthesized and employed to fabricate black matrices with low dielectric constant and light absorption in the whole visible region. The spectral and thermal properties and solubility of the prepared dyes were investigated, and optical, thermal and dielectric properties of the dye-based black matrices were examined. For further investigation of surface morphology of the black matrix films, dye-based black matrices were probed by field emission scanning electron microscopy and atomic force microscopy. The dye-based black matrix showed the high thermal stability due to the rigid molecular structures of the dyes. In addition, due to the low dielectric characteristics of the dye, the dielectric constants of the dye-based black matrices were significantly lower than that of the black matrix prepared with carbon black only. However, the low solubility of the dyes in industrial solvents and dye aggregations in the baking process limited the input of the dye in the black matrix resist, resulting in low light absorption of the dye-based black matrix. Dye-sensitized solar cells have attracted considerable attention as promising solar devices and the Ru complex dyes typical used as sensitizers in dye-sensitized solar cells have shown high electronic conversion efficiencies of over 11% with good stability. However, high production cost and difficulties in purification of Ru complex dyes have limited their development for large-scale applications. Recently, more attention has been paid to sensitizers without Ru (metal-free organic dyes and organometallic dyes) due to their lower cost, easier modification and purification, high molar extinction coefficient, and environmental friendliness. Phenoxazine-based sensitizers have exhibited higher conversion efficiencies than triphenylamine and phenothiazine-based sensitizers, which are structurally similar. This is because phenoxazine-based sensitizers, with electron-rich nitrogen and oxygen heteroatoms, have stronger electron-donating ability than triphenylamine and phenothiazine-based sensitizers. phenoxazine-based sensitizers also show sufficient electrochemical properties for use in dye-sensitized solar cells. However, despite their potential for application to dye-sensitized solar cells, phenoxazine-based sensitizers have not been studied extensively. In this research, to study effects of conjugated bridges with a phenoxazine moiety on photovoltaic performance, five-membered heterocyclic rings were introduced as a conjugated bridge unit to phenoxazine molecules. Furthermore, to improve the donating power and molar extinction coefficient, an ethoxy phenyl ring was substituted in the 7 position of the phenoxazine -furan dye as an additional donor. Based on these strategies, three organic dyes were synthesized and the photophysical, electrochemical, and photovoltaic properties of the solar cells based on these dyes were investigated. The introduced heterocyclic bridge units furan and thiophene improved the short-circuit current due to the red-shifted absorption spectra of the dyes. The ethoxyphenyl ring introduced to the phenoxazine moiety as an additional donor broadened the spectrum of the dye, while the reduced adsorption of the dye caused by its non-planar structure limited the enhancement of the short-circuit current. As a result, among the synthesized dyes, the one with furan as a bridge unit showed the best overall conversion efficiency of 5.26%. In addition, to study the effects of the number of anchoring groups and N-substitution on the performance of phenoxazine dyes in dye-sensitized solar cells, cyanoacrylic acid as an additional anchoring group was introduced to the phenoxazine for efficient electron extraction from the donor part, and an N-methoxyphenyl unit was added to suppress dye aggregation. Based on these strategies, four phenoxazine derivatives were synthesized and the photophysical, electrochemical and photovoltaic properties of the solar cells based on these dyes were investigated. The additional cyanoacrylic acid acceptor improved the short-circuit current because it widened the absorption ranges of the dyes, although it also increased the recombination rate. The N-methoxyphenyl unit decrease charge recombinations, resulting in higher open-circuit voltage. However, the bulky substituent decreased the amount of dye absorbed on the TiO2. As a result, the fabricated cells with the four dyes exhibited similar overall conversion efficiencies and, of these cells, the solar cell based on the N-4-methoxyphenyl mono-cyanoacrylate substituted dye showed the highest conversion efficiency of 5.09%.Contents Abstract Contents List of Tables List of Schemes List of Figures Chapter 1. Introduction 1.1 An overview of LCDs (Liquid Crystal Displays) 1.2 Structures and requirements of LCD black matrix 1.3 Fabrication of black matrix pattern using black matrix photo-resist 1.4 An overview of DSSCs (Dye-sensitized Solar Cells) 1.5 Operating principle and fabrication of DSSCs 1.6 Requirements of organic sensitizers 1.7 References Chapter 2. Synthesis and characterization of solubility enhanced metal-free phthalocyanines for liquid crystal display black matrix of low dielectric constant 2.1 Introduction 2.2 Experimental 2.2.1 General 2.2.2 Synthesis 2.2.3 Preparation of dye-based black matrix 2.2.4 Measurement of spectral and chromatic properties 2.2.5 Measurement of solubility 2.2.6 Measurement of thermal stability 2.2.7 Geometry optimization of the synthesized dyes 2.3 Results and Discussion 2.3.1 Synthesis of dyes 2.3.2 Solubility 2.3.3 UV-vis absorption spectra 2.3.4 Thermal properties 2.3.5 Dielectric properties 2.4 Conclusions 2.5 References Chapter 3. Analysis and characterization of dye-based black matrix film of low dielectric constant containing phthalocyanine and perylene dyes 3.1 Introduction 3.2 Experimetal 3.2.1 General 3.2.2 Synthesis 3.2.3 Preparation of dye-based black matrix 3.2.4. Measurement of spectral and optical properties 3.2.5 Investigation of solubility 3.2.6 Measurement of thermal stability 3.2.7 Field emission scanning electron microscopy and Atomic force microscopy 3.3 Results and Discussion 3.3.1 Properties of dyes 3.3.2 Spectral and optical properties of dye-based black matrix 3.3.3 Thermal properties of dye-based black matrix 3.3.4 Dielectric properties of dye-based black matrix 3.3.5 Surface investigation of BM film by FE-SEM and AFM 3.4 Conclusion 3.5 References Chapter 4. The effect of five-membered heterocyclic bridges and ethoxyphenyl substitution on the performance of phenoxazine-based dye-sensitized solar cells 4.1 Introduction 4.2 Experimental 4.2.1 Materials and reagents 4.2.2 Analytical instruments and measurements 4.2.3 Fabrication of dye-sensitized solar cells and measurements 4.2.4 Synthesis of dyes 4.3 Results and Discussion 4.3.1. Synthesis 4.3.2 Photophysical properties 4.3.3 Electrochemical properties 4.3.4 Photovoltaic properties 4.4 Conclusion 4.5 Reference Chapter 5. The effects of the number of anchoring groups and N-substitution on the performance of phenoxazine dyes in dye-sensitized solar cells 5.1 Introduction 5.2 Experimental 5.2.1 Materials and reagents 5.2.2 Analytical instruments and measurements 5.2.3 Fabrication of dye-sensitized solar cells and measurements 5.2.4 Synthesis of dyes 5.3 Results and Discussion 5.3.1 Synthesis of dyes 5.3.2 Density functional theory (DFT) calculations 5.3.3 Photophysical properties of the dyes in solution and on TiO2 film 5.3.4 Electrochemical properties 5.3.5 Photovoltaic properties 5.3.6 Electrochemical impedance spectroscopy 5.4 Conclusion 5.5 References Summary Korean Abstract List of Publications List of PresentationsDocto