Trinitrobenzene sulfonic acid로 유도한 대장염에서 대장통과시간 변화 및 장벽내 nitric oxide synthase의 분포

의학과/석사[한글] Nitric oxide (NO)는 대장에서 연동 반사시 미측 윤상근의 이완에 관여하는 물질로서, 정상적인 생리조건에서는 endothelial nitric oxide synthase (eNOS) 및 neuronal NOS (nNOS)에 의해 주로 생성되며, 대장염시에는 다양한 염증세포로부터 합성된 inducible NOS (iNOS)에 의해 생성되는 것으로 알려져 있다. 최근 박 등은 trinitrobenzene sulfonic acid (TNBS) 유도 기니 픽 대장염 모델에서 대장통과 시간은 약제 주입 후 3일째부터 유의하게 지연되지만 염증의 정도와 상관 관계를 보이지 않으며, 무스카린성 수용체를 통한 평활근 세포의 수축 반응에는 이상이 없음을 보고하였다. 본 연구에서는 기니 픽에게 TNBS로 유도한 실험적 대장염 모델에서 대장통과시간의 변화 여부를 관찰하고, TNBS 노출 기간에 따른 nNOS와 iNOS의 장벽내 분포를 조사하여 대장통과시간 변화와 니트레직(nitrergic) 신경분포와의 상관 관계를 알아보고자 하였다. 실험 결과, 대장통과시간은 TNBS 투여군에서 3, 7, 14일 째에 대조군에 비하여 유의하게 지연되는 것을 관찰하였다. nNOS 양성 세포는 대조군에서 점막, 점막하층, 고유근층, 점막하 신경총, 그리고 장근 신경총에서 골고루 관찰되었다. TNBS 주입군에서는 주로 염증이 유발된 점막 및 점막하층에서 nNOS 양성 세포의 감소가 관찰되었으나, 각 군에서 장근 신경총의 nNOS 양성 신경세포의 수는 유의한 차이를 보이지 않았다. iNOS 양성 세포는 대조군에서 주로 점막하 신경총 및 장근 신경총에서 관찰되었다. TNBS 주입군에서는 주로 염증이 유발된 점막 및 점막하층에서 iNOS 양성 세포의 증가가 관찰되었으나 TNBS 노출기간에 따른 변화는 관찰되지 않았으며, 각 군에서 장근 신경총 내 iNOS 양성 세포의 수는 유의한 차이를 보이지 않았다. 결론적으로 TNBS 유도 기니 픽 대장염에서 대장통과시간이 유의하게 지연되었으며, 장근 신경총내 nNOS와 iNOS 양성 세포의 분포변화는 대장통과시간 변화에 주 역할을 하지 않는 것으로 생각된다. [영문]Inflammation-induced alterations in smooth muscle contractility may be due to effects on smooth muscle itself, or its response to neurotransmitters or to effects on enteric nerves. Colonic transit in trinitrobenzene sulfonic acid (TNBS)-induced colitis of guinea pigs is delayed significantly, but it is not related to the muscarinic receptor-mediated contractions. In dextran sulfate sodium-induced colitic rat, the delay in colon-ic transit was caused by decreased activity and production of neuronal nitric oxide synthase (nNOS) in the myenteric plexus in the distal colon. In this study, we investigated the distribution of inducible NOS/(iNOS) and nNOS immunoreactive cells in the myenteric plexus and colonic wall to explain the involvement of NOS in delayed colonic transit in TNBS-induced colitic guinea pig. Colonic transit was delayed significantly at 3, 7 and 14 days after administration of TNBS compared to control. In control, nNOS immunoreactivity was present in the mucosa, submucosa, lamina propria, muscularis mucosa, and in ganglion cells within the myenteric plexus, while after TNBS, reduced nNOS cells were found. However, the number of nNOS immunoreactive ganglion cells in the myenteric plexus was similar to that seen in controls. After administration of TNBS, iNOS immunoreactivity was increased in the mucosa and submucosa compared to that in control, but the number of distribution of iNOS immunoreactive ganglion cells in the myenteric plexus was not changed compared to that in control. In conclusion, it is suggested that in TNBS-induced guinea pig colitis, delayed colonic transit is not associated with the expression of nNOS or iNOS in the myenteric plexus.ope

Correlation between Clinical Symptoms and Radiologic Findings before and after Pneumatic Balloon Dilatation for Achalasia

Background/Aims: We investigated the risk factors for short-term recurrence and analyzed the correlation between subjective clinical symtoms and objective radiological findings in patients with achalasia undergoing pneumatic balloon dilatation. Methods: Twenty patients who were treated by pneumatic balloon dilatation were enrolled. We compared prospectively various indices before and after the treatment as follows: 1) Eckardt symptom score and dysphagia grade, 2) The ratio of the maximal width in mid-esophageal lumen to the minimal width in distal esophagus around lower esophageal sphincter, and 3) the percentage of maximum activity retained in the esophagus at 30 seconds and T½ in esophageal scan two days after the treatment. Results: 1) Clinical indices and radiologic indices significantly improved after pneumatic dilatation. 2) There was no significant correlation between the clinical indices and the radiologic indices before and after the treatment. 3) The difference percentage of clinical indices did not show significant correlation with the difference percentage of the radiologic indices. 4) Compared to the group above 20% in the difference percentage of 30 second residual fraction, the one below 20% had a four-fold risk in short-term recurrence. Conclusions: Clinical symptoms and radiologic indices significantly improve after pneumatic dilatation but have no significant correlation to each other. The group below 20% in the difference percentage of 30 second residual fraction has a high risk of recurrence and may need careful examination and early repeated pneumatic dilationope

A Case of the Main Pancreatic Duct Injury Due to Blunt Abdominal Trauma Cured by Conservative Management Including Octreotide Admonistration

ope

마그네토스트릭션 효과를 이용한 비접촉 모달 테스팅 기법

Thesis (master`s)--서울대학교 대학원 :기계항공공학부,2001.Maste

극저주파에 의한 가돌리늄의 세포유전독성 증진효과

Gadolinium (Gd) is widely used for various industrial and medical purposes, particularly in magnetic resonance imaging (MRI) contrast agent. As there has been a large volume of studies about cyto- and geno- toxicity of Gd, it has been utilized as derivatives by chelation with various ligands. Human exposure to Gd and its derivatives is significantly increasing, posing a high risk of accumulation and retention. It is important to investigate the effect of extremely low-frequency electromagnetic fields (ELF-EMF) on the cyto- and geno-toxicity of Gd, since patients are co-exposed to Gd and ELF-EMF generated by MRI scanner. The aim of this study is to investigate the cyto- and geno-toixcity of Gd and the possible enhancing effect of ELF-EMF on the toxicity of Gd in cultured human peripheral blood lymphocytes by performing micronuclei (MN) assay, single cell gel electrophoresis (Comet) assay, trypan blue dye-exclusion assay, apoptosis analysis using flow cytometry and intracellular reactive oxygen species measurement. MN frequencies were 13.0, 14.0, 15.3 and 17.7 per 1000 cells in Gd treatment cells at concentrations of 0, 0.4, 0.8 and 1.2 mM. ELF-EMF exposure (0.8 mT) increased the frequencies of MN induced by Gd treatment alone; 13.3, 17.0, 20.3 and 25.0 per 1000 cells at each Gd concentrations. ELF-EMF exposure also increased cell death, olive tail moment (OTM), apoptosis and ROS level induced by Gd treatment alone. These results suggest that Gd induces DNA damage, apoptotic cell death and ROS generation in human lymphocytes and ELF-EMF can enhance the cyto- and geno-toxicity of Gd.1. Introduction 1 2. Materials & Methods 4 2. 1. Isolation, culturing and stimulation of peripheral blood lymphocytes 5 2. 2. Gd treatment and ELF-EMF exposure condition 5 2. 3. Measurement of cell death 6 2. 4. Cytokinesis-block micronuclei (CBMN) assay 6 2. 5. Single-cell gel electrophoresis (comet) assay 7 2. 6. Detection and quantification of apoptosis 8 2. 7. Measurement of intracellular ROS 9 2. 8. Statistical analysis 10 3. Results 10 3. 1. ELF-EMF enhances Gd-induced cell death in peripheral blood lymphocytes 11 3. 2. ELF-EMF enhances Gd-induced micronuclei in peripheral blood lymphocytes 13 3. 3. ELF-EMF enhances Gd-induced DNA damage in peripheral blood lymphocytes 15 3. 4. ELF-EMF enhances Gd-induced apoptosis in peripheral blood lymphocytes 17 3. 5. ELF-EMF enhances the generation of ROS induced by Gd 19 4. Discussion 23 5. Conclusion 30 6. Reference 31Maste

자기변형을 이용한 유도초음파 및 진동 트랜스듀서의 설계

Thesis(doctoral)--서울대학교 대학원 :기계항공공학부,2006.Docto

대화형 유전 알고리즘을 이용한 이미지 색 양자화

학위논문 (석사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2015. 2. 문병로.Color image quantization is the problem of converting the given image to the image with limited number of colors used, maximizing the similarity. Previous studies measured the similarity as the smaller color difference by pixels, which is hard to evaluate the context of the image. In this thesis, a novel approach of considering the context is shown. Interactive genetic algorithm is applied to reflect the human knowledge in generating the quantized images. The experiment of the system has been done with 12 subjects and four test images, and the result shows that the quantized images generated with the interactive system are evaluated to be more suitable than those with the traditional optimization methods.Abstract i Contents ii List of Figures iv List of Tables v Chapter 1 Introduction 1 Chapter 2 Preliminaries 4 2.1 Color Image Quantization Problem 4 2.2 Genetic Algorithm 5 2.3 Hybrid Genetic Algorithm 8 2.4 Interactive Genetic Algorithm 9 Chapter 3 The Proposed System 11 3.1 Formulation of the Problem 11 3.2 The Framework of the System 11 3.3 The Structure of Chromosomes 14 3.4 Interactive Step and Evolutionary Step 15 3.5 Measurement of Fitness 17 3.6 Local Optimization 17 Chapter 4 Experiment 19 4.1 Experimental Setup 19 4.2 Generated Image 20 4.3 Comparison of Results 21 Chapter 5 Conclusion 24 요약 28Maste

NudH에 의한 대장균 질소인산전달계의 인산화 및 ?S 의 활성 억제

Thesis(doctors) --서울대학교 대학원 :생명과학부, 2009.2.Docto

종방향 스트립을 이용한 낮은 레이놀즈 수 익형 주변 유동 제어

학위논문 (박사)-- 서울대학교 대학원 : 공과대학 기계항공공학부, 2019. 2. 최해천.본 연구에서 종방향 스트립을 익형의 표면에 설치하여 실속을 제어하였다. 종방향 스트립에 의한 실속 지연과 유동 제어 메커니즘을 실험적으로 규명하였다. 익형은 SD7003이며, 자유류 속도와 익형 코드 길이를 기준으로 하는 레이놀즈 수는 60,000과 180,000이다. 스트립이 있는 경우와 없는 경우 각각에 대해 받음각을 0°에서 16° 까지 변화시키며 양력과 항력을 직접 측정하였다. 스트립의 최적 형상은 반응표면법(Response surface method)에 의해 얻어졌다. 스트립이 없는 경우에, 레이놀즈 60,000과 180,000에서 급격한 실속이 각각 11°와 13°에서 일어났다. 반면, 최적 형상을 갖는 strip이 설치되었을 때 이러한 급격한 실속이 발생되지 않는다. 이러한 스트립에 의해 실속 이후 양력 계수는 현저히 증가되었으며, 항력 계수는 감소되었다. 코너 볼텍스가 익형의 선단 부근의 strip의 양 코너에서 발생함을 확인하였다. 시계방향 및 반시계 방향의 유선형 볼텍스가 각각 스트립의 왼쪽 및 오른쪽 코너에서 발생하였으며, 이는 하류로 이동함에 따라 점차 모서리에서 멀어지게 된다. 이러한 볼텍스들은 익형의 흡입면에 추가적인 모멘텀을 공급하여 결과적으로 스트립에서의 부착유동을 유지하게 함과 동시에 익형 위에서의 선단 유동 박리를 재부착시키게 된다. 이러한 종방향 스트립은 이전의 낮은 레이놀즈 수 조건에서 실속을 제어하기 위한 제어장치인 와류 발생기나, 트립 와이어, 버스트 제어판(Burst control plate) 등과 차별점을 갖는다. 즉, 스트립은 상대적으로 매우 작은 높이 (경계층 높이보다 작은)를 가짐과 동시에 전체 익형 표면에 설치됨으로써 효과적인 실속 제어 효과를 가짐에도 실속 이전의 낮은 받음각에서의 공력 성능 에 크게 영향을 주지 않게 된다. 종방향 스트립의 실제 적용 가능성을 확인하기 위해 스트립을 수직축 풍력 발전기(VAWT) 모델에 적용하여 실험적으로 발전 성능의 향상을 확인하였다. 이 때, 수직축 풍력 발전기에서 익형은 주기적인 받음각의 변동을 겪기에 일반적으로 대칭 익형을 사용하게 된다. NACA0018 익형이 널리 쓰이며, 이에따라 실제 수직축 풍력 발전기에 스트립을 적용하기 전에 NACA0018 익형에 스트립을 적용하여 양력 및 항력을 측정함으로써 실속 제어 효과를 조사하였다. SD7003에서와 동일하게 급격한 실속 현상이 스트립에 의해 사라지며 그 결과 실속 이후의 높은 받음각에서 매우 향상된 양항비를 가짐을 확인하였다. VAWT 모델에 스트립을 적용하여 발전 성능을 측정한 결과, 스트립에 의해 성능 계수가 상승함을 확인하였으며, 이는 스트립의 실속 제어 장치로서의 실제적 가능성을 보여준다 할 수 있다.We suggest longitudinal strips attached to an airfoil surface as a new stall control device. Their effects on the stall delay and flow modifications are experimentally investigated. The airfoil considered is SD7003 and the Reynolds numbers are Re = 60,000 and 180,000 based on the chord length and freestream velocity. The drag and lift forces on the airfoil are measured by varying the angle of attack from α = 0° to 16° with and without strips. The optimal strip configuration is determined using a response surface method. Without strip, an abrupt stall occurs at α = 11° and 13° for Re = 60,000 and 180,000, respectively, whereas the abrupt stall disappears with optimal strips. The lift and drag coefficients are significantly increased and decreased by the strips, respectively, at post-stall angles of attack. A corner vortex is generated at each corner of strip near the leading edge. Clockwise and counter-clockwise streamwise vortices are generated at the left- and right-facing corners, respectively, and they slowly move away from the corners while travelling downstream. These vortices provide additional momentum to the airfoil suction surface, resulting in fully attached flow above the strips and reattachment of flow above grooved surface. The longitudinal strips presented here are different from other devices such as the vortex generator, trip wire and burst control plate used for the stall control of low Reynolds number airfoil, in that the strips are installed nearly on the whole airfoil surface but with their heights lower than the boundary layer thickness, and produce positive control effects at post-stall angles of attack but little affect the aerodynamic performance at pre-stall angles of attack. To examine the applicability of the strips, we installed the strips to the vertical axis wind turbine (VAWT) model. For VAWTs a symmetric airfoil is commonly used because of the periodic change of angle of attack (minus to plus). NACA0018 airfoil is widely used, then we investigate the stall control effect of the strips by directly measuring drag and lift forces. The abrupt stall is modified to a broad stall and the lift-to-drag ratio in a post-stall region is significantly enhanced with the strips. In a VAWT models, the strips also increasing the performance of the wind turbine model showing that the applicability of the strips as a stall control devices.1. Introduction 1.1 Low Reynolds number airfoils and the effect of the laminar separation bubble (LSB) 1.2 Separation control devices 1.3 Objectives 2. Experimental setup 2.1 Two-dimensional experimental setup for direct force measurements 2.2 Parameters for a strip and shape optimization using a response surface method 2.3 Surface-oil visualization 2.4 Digital particle image velocimetry 2.5 Surface pressure measurements 3. Results and discussion 3.1 Shape optimizations using a response surface method and aerodynamic performance enhancements 3.2 The mechanisms responsible for the stall control 3.3 Effect of the strip length 4. Summary 5. Introduction 5.1 Wind power generation methods 5.2 The aerodynamic characteristics of VAWT 5.3 Objectives 6. Experimental setup 6.1 Two-dimensional experiment setup for a direct force measurement 6.2 Shape parameters for a VAWT model and direct torque measurements 7. Results and discussion 7.1 The aerodynamic performance of NACA0018 airfoil with and without the strips 7.2 The performance of VAWT model with and without strips 8. Summary and concluding remarksDocto