Clinical Significance of Marshmallow Esophagography in Patients with Nutcracker Esophagus and Ineffective Esophageal Motility

Background/Aims: Ineffective esophageal motility (IEM) and a nutcracker esophagus can lead to hypocontractile dysmotility and hypercontractile dysmotility, respectively. We evaluated patients for the abnormalities of marshmallow esophagography and we compared the esophageal symptoms with the esophageal manometric findings in the patients. Methods: We included total 96 patients; there were 23 patients with IEM, 36 patients with nucracker esophagus, 37 individuals with esophageal symptoms who remained in the the normal esophageal manometric group, and 9 asymptomatic healthy controls. The distal esophageal body pressure and the lower esophageal sphincter pressure were examined with respect to the grade of marshmallow esophagography. Results: The nine healthy volunteers displayed no abnormal marshmallow transit. However, 43.5% of the patients with IEM and 36% of the patients with nutcracker esophagus displayed abnormal marshmallow transit. There was a statistical difference between the healthy volunteer group and those patients with nutcracker esophagus or IEM (p<0.05). Abnormal marshmallow esophagography occurred more frequently for the non-transmitted contraction and the combined type of IEM (non-transmitted contraction and low-amplitude contraction) (p<0.05). However, there was no difference between the distal esophageal pressure and the grade of the marshmallow esophagography. Furthermore, nutcracker esophagus did not display any significant relationship with the distal esophageal pressure and the lower esophageal sphincter pressure with respect to the grade of the marshmallow esophagography. Conclusions: Although the measurement of the distal esophageal pressure and the lower esophageal sphincter pressure did not provide statistically significance for the marshmallow transit in IEM and the nutcracker esophagus, the non-transmitted contraction and the combined type provided a statistically significant result for IEM.ope

페브리 페로 구조 기반 웨어러블 컬러 가스센서

학위논문(박사) -- 서울대학교대학원 : 공과대학 기계항공공학부, 2022.2. 안성훈.나노 마이크로 기술을 이용하여 고감도 가스 감지 물질이 개발되었으며, 이를 이용한 웨어러블 장치 형태의 가스 센서 개발은 유망한 연구 주제이다. 그러나 센서의 높은 전류 소비와 작동 온도를 극복하는 것은 많은 가스 감지 영역에서 여전히 과제로 남아 있다. 이를 개선하기 위해 센서 기술에 나노 패턴 구조의 구조적 착색을 이용한 컬러 가스 센서가 새로운 대안으로 떠오르고 있다. 그러나, 리소그래피 기반의 나노 패터닝 공정은 환경 친화적이지 않으며 이러한 접근 방식과 관련된 제한으로 인해 넓은 색상 영역을 제작하기가 어렵다. 또한 색 변화 측정, 데이터 정량화, 각도 의존성 등의 문제로 적용 확대에 어려움을 겪고 있으며, 컬러 센서에 대한 많은 연구에서 이 부분을 간과하고 있다. 본 연구에서는 나노 패터닝 공정이 필요하지 않은 Fabry-Perot 캐비티를 기반으로 상온에서 반응할 수 있는 컬러 가스 센서를 개발하였다. FDTD를 이용하여 특정 파장에서 선형 변화 주기를 갖는 컬러 센서 소자를 설계하였다. 이러한 특성을 가진 컬러 센서와 간단한 측정 장치인 PPG 센서를 결합하여 저전력으로 신호를 정량화하는 메커니즘을 개발하였다. 센서 교체가 가능한 구조를 도입하여 다중 가스 감지 및 비가역 센서도 지속적으로 사용이 가능하게 하는 와치형 웨어러블 감지 장치를 제작하고, 그 결과 상온에서 NO2 (0.1~500ppm)의 넓은 농도범위를 갖는 가스센서를 구현하였다. 최종적으로 상온에서 다층 컬러 필름을 이용하여 유해 가스를 감지하고, 저전력의 단색 LED를 이용하여 신호를 정량화하고 무선으로 통신할 수 있는 웨어러블 가스 센서의 가장 단순화된 설계를 제시하였다.Highly sensitive gas-sensing materials have been developed using nano/microtechnology, and the development of gas sensors in the form of wearable devices is a promising research topic. However, overcoming the sensor’s high current consumption and operating temperature remains a challenge in many gas-sensing areas. For resolving these issues, a colorimetric gas sensor that uses the structural coloration of the nano-patterned structure for sensing is emerging as a new alternative. However, lithographic nanopatterning processes are not ecofriendly, and the limitations associated with these approaches make it difficult to fabricate large gamuts of colors. Furthermore, extending the range of applications is difficult owing to problems such as measurement of color changes, data quantification, and angular dependence, and many studies on colorimetric sensors overlook these aspects. In this study, we developed a colorimetric gas sensor that can respond at room temperature. It is based on a Fabry–Perot cavity and does not require a nanopatterning process. A colorimetric sensor element having a linear change period at a specific wavelength was designed using the finite-difference time-domain method. A mechanism for quantifying signals with low power was developed by combining a colorimetric sensor having the aforementioned characteristics with a photoplethysmogram sensor, i.e., a simple measuring device. We designed a structure that allows sensor replacement and manufactured a watch-type wearable sensing device that has irreversible sensors and is capable of multi-gas sensing. A gas sensor with a wide concentration range for NO2 (0.1–500 ppm) at room temperature was obtained, and reliability of >95% was realized in a 5-ppm NO2 environment using artificial intelligence. Finally, we presented the simplified design of a wearable gas sensor that detects harmful gases using a multilayer color film at room temperature and quantifies color changes using a monochromatic light-emitting diode.ABSTRACT i LIST OF FIGURES v LIST OF TABLES viii Chapter 1. Introduction 1 Chapter 2. Fabry-Perot Color 10 Chapter 3. NO2 gas sensor 25 Chapter 4. Measument & data processing 57 Chapter 5. Application 74 Chapter 6. Conclusion 90 Bibliography 94 Abstract in Korean 100박

A Study on the Methodology for Undertaking the Port Facility Security Assessment of the ISPS Code

It has been identified through this study that a security assessment which is undertaken in advance of establishing a port facility security system should be performed correctly in order to ensure that the system is set up in accordance with the ISPS Code. Also it was found that an appropriate methodology is required to undertake the port facility security assessment in a correct manner. The risk assessment methodology applied in the safety fields has been adopted as the methodology for the security assessment for this study. This study looks at seven stages of risk assessment. At first stage, the identification and evaluation of important assets and infrastructure requiring protection is carried out. Such undertakings are needed to clearly identify the function of the assets and infrastructure within the port facility, ascertain ones that are to be protected from security threats or security incidents, decide on their relative importance, and determine which ones are to be subjected to the security assessment. All identified assets and infrastructure should be included in the evaluation. Three parts should be considered in the evaluation. First, the role or objective of the assets and infrastructure in the operation of the port facility should be considered. The next consideration should be the effect of destruction. Finally, the ability to recover from destruction of the assets and infrastructure should be considered. At second stage, an on-site security survey is carried out. An on-site security survey is a process through which the present security conditions of the port facility and of the important assets and infrastructure within port facility can be identified. When conducting such on-site security survey, security procedures, security organizations, security equipments and systems, and the security ability of the port facility personnel having specific security duty should be considered. At third stage, the identification of the possible threat scenarios and security incidents to the important assets and infrastructure is carried out. The security incidents that had occurred in the past and the security rule or regulations for the security in force should be considered at the time of identifying the security threats and incidents. And the consultation with the security expert authority should also be carried out. At fourth stage, the assessment of consequence and vulnerability is carried out. The consequence and vulnerability should be evaluated to confirm the effect of identified security incident and the probability of the target to the attack. Five elements are included in the consequence assessment: death and injury, economic impact, environmental impact, national defense impact, and symbolic effect. And the vulnerability assessment should be evaluated in two parts: accessibility and organic security. The results of the on-site security survey carried out at the second stage should be considered in the vulnerability assessment. At fifth stage, the security risk level is determined. The security risk level should be determined based on the level of consequences and vulnerability. The security risk is classified into three levels: mitigate, consider and document. "Mitigate" means that mitigation strategies should be developed to reduce risk for that threat scenario. "Consider" means that the threat scenario should be considered and mitigation strategies should be developed on a case-by-case basis. "Document" means that the threat scenario does not need a mitigation measure at this time and therefore need only to be documented. At sixth stage, the mitigation targets and implementation methods is determined. The mitigation targets should be identified based on the security risk level. And the mitigation methods to be implemented for that target should be decided based on the effectiveness and possibility of the methods. Generally, it is required to consider the mitigation strategies in lowering vulnerabilities in advance than the mitigation strategies in lowering consequences. At seventh stage, the security risk reassessment is carried out. And the confirmation of mitigation measures is carried out based on the result of the reassessment. A security risk reassessment to the mitigation measures determined at the sixth stage should be practiced to confirm whether the measures can actually reduce the security risk level. The reassessment should be started from the fourth stage. If the security risk level is not reduced as the result of the reassessment, another mitigation measures should be considered for implementation. If the security risk is reduced as the result of the reassessment, the mitigation measures should be adopted and planned to be put into action in the port facility security system.Abstract VI 제1장 서론 1 제1절 연구의 배경 1 제2절 연구의 목적 4 제3절 연구의 방법 및 구성 5 제2장 ISPS Code의 제정 및 내용에 대한 분석 6 제1절 ISPS Code 제정 배경 6 제2절 ISPS Code 채택 및 SOLAS 협약에 반영된 과정 6 제3절 ISPS Code의 신속한 채택 및 발효가 가지는 의미 7 제4절 SOLAS 제11-2장의 구성 및 내용 8 1. SOLAS 제11-2장의 구성 8 2. SOLAS 제11-2장 각 규칙의 내용 요약 9 제5절 ISPS Code 구성 및 내용 18 1. ISPS Code의 종류 및 성격 18 2. ISPS Code의 구성 19 3. ISPS Code A편의 내용 20 4. ISPS Code B편의 내용 37 제3장 항만시설 보안평가 모델의 구축 49 제1절 위험성 평가 분야의 선정 49 제2절 위험성 평가에 연관된 개념들에 대한 정의 50 제3절 사고와 손실의 인과 관계에 대한 이론적 전개 54 제4절 위험성 평가 58 1. 위험성 평가의 이론적 전개 58 2. 위험성 평가 방법의 종류 60 제5절 위험성 평가 시행 방법 62 1. 운영중인 시스템이나 수행중인 작업에 대한 전개 62 2. 위험파악 62 3. 발생결과 평가 63 4. 빈도/가능성 평가 63 5. 위험성 산정 및 등급 결정 63 6. 개선대책 수립 65 7. 개선대책에 대한 위험성 재평가 66 제6절 ISPS Code에서 요구하는 항만시설 보안평가 67 1. ISPS Code에 규정된 항만시설 보안평가 요건 67 2. 항만시설 보안평가의 목적 및 의의 70 제7절 항만시설 보안평가 70 1. 항만시설 보안평가의 구성 요소 70 2. 항만시설 보안평가와 연관된 개념들에 대한 정의 71 3. 항만시설 보안평가 모델 구축 72 제4장 항만시설 보안평가 모델의 적용 75 제1절 보호해야 할 주요대상 식별 및 우선순위 평가 75 1. 목적 75 2. 식별 및 평가 기준 75 3. 우선순위 평가 방법 76 4. 우선순위 평가결과에 대한 관리 79 제2절 현장보안상태 확인 79 1. 목적 79 2. 현장보안상태 확인방법 79 제3절 위협 시나리오 및 보안사건 식별 80 1. 목적 80 2. 식별 방법 81 제4절 심각성 및 취약성 평가 84 1. 목적 84 2. 평가 방법 84 제5절 보안위험성 등급 평가 87 1. 목적 87 2. 평가 방법 87 제6절 완화조치 대상 선정 및 완화조치 방법 결정 88 1. 목적 88 2. 시행 방법 88 제7절 보안위험성 재평가 및 완화조치 확정 89 1. 목적 89 2. 재평가 시행 방법 89 제8절 항만시설 보안평가 실제 적용 사례 90 1. 대상 항만시설 90 2. 항만시설 보안평가 90 제5장 결론 114 제1절 연구 결과의 요약 114 제2절 연구 결과의 시사점 117 제3절 연구의 한계와 향후 과제 118 참고문헌 12

Chronic Idiopathic Intestinal Pseudo-obstruction in Adult: A Case Report with a Clinical Analysis of Other Reported Cases in Korean Literature

Chronic intestinal pseudo-obstruction syndrome is a rare, severe and disabling disorder characterized by repetitive episodes or continuous symptoms and signs of a bowel obstruction, including radiographic documentation of a dilated bowel with an air-fluid level, in the absence of a fixed lumen-occluding lesion. This term is used in acute cases as well as repetitive chronic intestinal pseudo-obstruction cases. Chronic intestinal pseudo-obstruction can be classified as idiopathic and secondary according to systemic disease. Histologically, idiopathic pseudo-obstruction can be divided into visceral myopathic and neuropathic subtypes. We report a case of chronic idiopathic intestinal pseudo-obstruction in a 31-year old woman recently admitted with repetitive postprandial abdominal distension and diarrheaope

Serotonin Transporter Gene Polymorphism and its Relationship to Plasma Serotonin in Irritable Bowel Syndrome

Background/Aims: Serotonin is an important mediator of intestinal peristalsis and it undergoes reuptake by a transporter protein (SERT). It has been reported that polymorphisms in the promoter for synthesis of SERT (SERT-P) influence the response to a serotonin reuptake inhibitor and a serotonin receptor antagonist. The aim of this study was to investigate gene polymorphism in the SERT-P in healthy adults and patients with irritable bowel syndrome (IBS) and a plasma serotonin level according to genetic polymorphism. Methods: SERT gene polymorphism was assessed by polymerase chain reaction on DNA chains in serum samples from 53 patients with IBS and 56 healthy adults. The platelet-depleted plasma serotonin level of a fasting state was quantitatively measured by ELISA. Results: There was no significant difference in the allele frequency between the IBS and the control group, and according to the subtypes of IBS patients. The platelet-depleted plasma serotonin level was significantly higher in IBS patients than in controls (P<0.05). However, there was no significant difference in the plasma serotonin level according to the subtypes of IBS or genetic polymorphism of SERT-P. Conclusions: SERT-P is not a key factor in determining the development of IBS in Korea. Patients with IBS have significantly higher fasting plasma serotonin levels than controls, irrespective of genetic polymorphism at SERT-P.ope

Fasting and Postprandial Analysis of Bowel Sounds and Plasma 5-hydroxytryptamine Level

Background/Aims: Auscultation of bowel sounds is a traditional technique for evaluating patients with abdominal symptoms. It is, however, subjective and qualitative method in general. Recently, analysis of bowel sounds becomes possible. We analyzed bowel sounds in healthy volunteers and measured platelet depleted plasma 5-hydroxytryptamine (5-HT) that may be associated with postprandial symptoms in irritable bowel syndrome. Methods: We recorded both fasting and postprandial bowel sounds for 30 minutes in 16 healthy volunteers with a sensitive electronic stethoscope attached to a digital recorder. The files were saved in computer as wav files and analyzed with a specialized program. Blood samples were also taken before and 1 hour after meal for 5-HT analysis. Results: Meal challenge made no statistically significant changes in the 5-HT concentrations and all the sound parameters including sound to sound interval, sounds/minute, average of sound amplitudes, sound length, percentage of bowel sounds representing sound clustering and dominant frequency of sounds. Conclusions:Postprandial changes in bowel sounds and plasma 5-HT were insignificant in healthy Korean volunteers.ope

A Case of Primary Pericardial Malignant Mesothelioma

Primary pericardial malignant mesothelioma is a lethal and rare cardiac neoplasm of mesodermal origin. Most cases are associated with history of pericarditis with constriction and/or tamponade. Authors experienced a case of primary pericardial malignant mesothelioma in a 55-year old female who had suffered from dyspnea and chest pain. Pericardial nodules revealed intense uptake by FDG-PET scan and confirmed as primary pericardial malignant mesothelioma by thoracoscopic biopsy. Here we report this case with a brief review of the relevant literatures12.ope

CFD Analyses on Cactus PSE(Problem Solving Environment)

'The Grid' means the collaboration of computing and experimental resources in dispersed organizations by high-speed network. It has been paid much attention for an unlimited number of potential resources available and the easiness to build collaborative environments among multiple disciplines. However, the difficulty in establishing the environments and accessing and utilizing the resources has prevented application scientists from conducting Grid computing. Thus, the present study focuses on building PSE(Problem Solving Environment) which assists application researchers to easily access and utilize the Grid. The Cactus toolkit, originally developed by astrophysicists, is used as a base frame for Grid PSE. Some modules are newly developed and modified for CFD(Computational Fluid Dynamics) analysis. Simultaneously, a web portal, Grid-One portal, is built for remote monitoring/control and job migration. Cactus frame through the web portal service has been applied to various CFD problems, demonstrating that the developed PSE is valuable for large-scaled applications on the Grid.OAIID:oai:osos.snu.ac.kr:snu2005-01/104/0000004648/32SEQ:32PERF_CD:SNU2005-01EVAL_ITEM_CD:104USER_ID:0000004648ADJUST_YN:NEMP_ID:A001138DEPT_CD:446CITE_RATE:0FILENAME:Cactus_PSE의_활용을_통한_전산유체역학_문제_해석.pdfDEPT_NM:기계항공공학부EMAIL:[email protected]:

Usefulness of Urinary Trypsinogen-2 Dipstick Test for Diagnosis of Acute Pancreatitis

Background/Aims: The clinical usefulness of urinary trypsinogen-2 dipstick test is still in controversy. We evaluated the usefulness of urinary trypsinogen-2 dipstick test in patients with acute pancreatitis. Methods: Urinary trypsinogen-2 dipstick test was prospectively performed in 50 patients with acute pancreatitis, 50 patients with non-pancreatic abdominal pain, and 50 healthy controls. Results: On admission, urinary trypsinogen-2 dipstick test was positive in 36 of 50 patients with acute pancreatitis (sensitivity, 72%) and in 4 of 50 patients with non-pancreatic abdominal pain (specificity, 92%). On the other hand, it was all negative in controls. The sensitivity and specificity of serum lipase were 78% and 94%, respectively. At 24 hours after admission, the positive rate of urinary trypsinogen-2 dipstick test rose from 72% to 94% (p＝0.02). The results of urinary trypsinogen-2 dipstick test was positive in 14 of 15 patients with severe pancreatitis and 22 of 35 patients with mild pancreatitis according to the criteria by Atlanta International Symposium, 1992. Conclusions: Urinary trypsinogen-2 dipstick test is comparable to serum lipase in diagnosing acute pancreatitis. Delayed measurement and severe pancreatitis are more likely to yield positive results with urinary trypsinogen-2 dipstick test. Thus, we suggest that the cut-off value of urinary trypsinogen-2 dipstick test should be lowered to increase its sensitivity.ope

Expression of cell cycle regulators during smooth muscle cell proliferation after ballon catheter injury of rat artery

학위논문(박사)--서울대학교 대학원 :의학과 외과학전공,1999.Docto