Survival and Recurrence Pattern after Curative Resection of Pancreatic Cancer

Background/Aims: The only hope for the cure of pancreatic adenocarcinoma is curative resection. However, the rate of recurrence after curative resection is higher than 50%. The aim, of this study were to analyze survival and the factors influencing survival and to evaluate the recurrence rate and pattern after curative resection of pancreatic adenocarcinoma. Methods: The records of 250 patients who were diagnosed as pancreatic cancer were reviewed retrospectively. We classified the patients into 3 groups (curative resection, non-curative resection, and conservative treatment) and analyzed the factors influencing survival, recurrence rate, and recurrence pattern after curative resection. Results: Curative resection were performed in 31 (12.4%) of 250 cases. The patients with curative resection was significantly prolonged median survival time than those without non-curative resection or with conservative treatment. The factors influencing survival rate after curative resection were age, lymph node involvement, and disease status. Twenty-five of the 31 cases with curative resection had recurrences after 10 months. Local retroperitoneal recurrence was 69%. Liver metastasis and lymph node metastasis were occurred in 61% and 54%, respectively. Conclusions: The survival time of the patients with pancreatic adenocarcinoma was prolonged in the cases of curative resection compared with the cases of non-curative resection or conservative treatment. However, most cases after curative resection showed recurrence. Thus, early diagnosis and early treatment should be needed to prolong the survival time of the patients with pancreatic adenocarcinoma.ope

비틀림파 자기변형 패치 트랜스듀서의 등가 회로 모델 연구

학위논문(박사)--서울대학교 대학원 :공과대학 기계항공공학부(멀티스케일 기계설계전공),2019. 8. 김윤영.The research in this dissertation aims at developing a fully coupled circuit model of a magnetostrictive patch transducer designed for generating and receiving the lowest torsional (T(0,1)) guided wave. Despite various types of magnetostrictive patch transducers have been developed, there appears no fully coupled circuit model to accurately account for the mechanism of wave actuation and sensing of the transducers. In addition, a circuit model to be useful for both wave actuation and sensing has not been proposed yet. Unlike piezoelectric transducers for which various circuit models for field variable quantification and their application are studied, however, the related research on the magnetostrictive patch transducers is very limited. The lack of such models makes it difficult for the magnetostrictive patch transducers to be further used in industrial applications. Motivated by this need, we aim to develop a fully coupled circuit model of a magnetostrictive patch transducer used to generate and measure the lowest torsional (T(0,1)) guided wave. Prior to construct the quantitative circuit model, we compared the field variables from the existing simplified constitutive equations of the magnetostriction with those of strain gauge to confirm the possibility of quantification. After that, in order to achieve the aim, structural impedances considering both a specimen and the transducer are obtained. Nonlinear magnetostriction phenomenon in a magnetostrictive patch which requiring magnetic material properties is expressed in the designed equivalent circuit. In particular, the static magnetic field caused by the magnet, which greatly influences the magnetostriction phenomenon, is also considered in the equivalent circuit. These processes form a single model that converts a voltage output from the transducer to the actual strain in the specimen and vice versa. The validity of the developed model was confirmed by comparing the values of the predicted field variables and those by experiments.본 논문에서는 최저차 비틀림 모드인 T(0,1) 탄성파를 가진, 그리고 측정하도록 설계된 자기변형 패치 트랜스듀서에 대한 완전 결합 회로 모델을 구축하고자 한다. 다양한 타입의 자기변형 패치 트랜스듀서가 개발되어 왔지만 트랜스듀서의 가진과 측정 메커니즘을 정확하게 고려하고 이를 표현한 회로 모델에 대한 연구는 제한적이었다. 특히, 정교하면서도 가진과 측정에서 동시에 사용할 수 있는 회로 모델의 경우는 아직까지 제시된 바가 없다. 모델을 통한 정량화 연구와 이에 따른 응용이 상당히 진행된 압전 트랜스듀서와 달리 자기변형 패치 트랜스듀서의 경우는 이러한 모델의 부재로 인해 정량화와 응용 측면에서 한계를 가졌다. 따라서 본 연구에서는 자기변형 패치 트랜스듀서의 정량화를 목표로 완전 결합 회로 모델을 설계하고 이에 대한 검증을 수행하였다. 정량적 회로 모델을 설계하기에 앞서, 기존의 단순화된 자기변형 구성 방정식을 통해 얻은 결과값을 스트레인 게이지와 상대적 비교를 하였으며 해당 결과는 자기변형 패치 트랜스듀서의 정량화 가능성을 확인해준다. 실제 회로 모델 설계에 있어서, 구조적 임피던스를 통해 시편과 트랜스듀서의 물리적 구조를 동시에 고려하였으며 자기변형 패치 내의 비선형성 자기변형 현상을 물성치와 함께 고려하여 등가 회로로 표현하였다. 특히, 자기변형 현상에 큰 영향을 주는 자석에 의한 정자기장도 회로 안에 함께 고려하여 가진과 측정, 두 방향성을 가질 수 있도록 설계하였다. 구조적 임피던스와 등가 회로를 하나로 모은 모델은 트랜스듀서에서 얻은 전압을 실제 변형률값으로 전환해주며 반대의 작용 또한 가능케 한다. 개발된 완전 결합 회로 모델은 검증된 스트레인 게이지와의 비교 실험들을 통해서 다양한 변수에 대한 유효성을 입증하였다.CONTENTS ABSTRACT CONTENTS LIST OF TABLES LIST OF FIGURES CHAPTER 1. INTRODUCTION ---1 1.1 Motivation ---1 1.2 Research Objectives ---2 1.3 Outline of thesis ---5 CHAPTER 2. THEORETICAL BACKGROUND ---8 2.1 Magnetostriction ---8 2.1.1 Overview of magnetostriction phenomenon ---9 2.1.2 Nonlinear properties of magnetostrictive material ---10 2.2 Guided waves in a hollow cylinder ---13 2.2.1 Wave equation in a hollow cylinder ---13 2.2.2 Torsional mode in a hollow cylinder ---16 2.3 Circumferential Shear-Horizontal (SH) mode in a hollow cylinder ---24 CHAPTER 3. MAGNETOSTRICTIVE PATCH TRANSDUCER FOR TORSIONAL ELASTIC WAVES ---43 3.1 Configuration of the magnetostrictive patch transducer ---44 3.2 Simplified analysis of magnetoelastic effect using magnetostriction equation ---45 3.2.1 Linear magnetostriction equation ---45 3.2.2 Effect of static magnetic field on the performance of magnetostrictive patch transducer ---52 3.3 Relative quantification with qualified strain gauge ---56 3.3.1 Experimental setup ---56 3.3.2 Experimental validation ---58 CHAPTER 4. STRUCTURAL IMPEDANCE MODEL OF SPECIMEN AND MAGNETOSTRICTIVE PATCH TRANSDUCER ---80 4.1 Structural impedance model ---81 4.1.1 Structural impedance configuration of specimen and magnetostrictive patch transducer ---81 4.1.2 Input impedance by transmission line theory ---83 4.2 Effective patch width by the shear lag phenomenon ---87 CHAPTER 5. FULLY COUPLED CIRCUIT MODEL FOR MAGNETOSTRICTION IN MAGNETOSTRICTIVE PATCH TRANSDUCER ---96 5.1 Fully coupled magnetostriction equation ---97 5.1.1 Approximate expressions for nonlinear properties of magnetostrictive material (HiperCo 50A) ---97 5.1.2 Improvement of magnetostriction equation with consideration of nonlinear properties ---99 5.2 Circuit model of torsional magnetostrictive patch transducer ---105 5.2.1 Circuit equations converted from the mechanical equations ---105 5.2.2 Equivalent circuit model based on torsional magnetostrictive patch transducer ---109 CHAPTER 6. EXPERIMENTAL VERIFICATION FOR QUALIFICATION OF MAGNETOSTRICTIVE PATCH TRANSDUCER WITH FULLY COUPLED CIRCUIT MODEL ---118 6.1 Experimental setup ---119 6.2 Comparison of field variables from the circuit model and those of the experimental results ---120 6.3 Database on measurement performance based on various variables ---122 6.3.1 Changes in measurement performance due to the structural variables ---122 6.3.2 Influence of static magnetic field by the permanent magnet ---124 CHAPTER 7. CONCLUSIONS ---139 APPENDIX A. MAGNETIC INTERFERENCES IN ULTRASONIC MAGNETOSTRICTIVE PATCH TRANSDUCERS ---141 A.1 Overview ---141 A.2 Analysis of the dynamic magnetic interference in a receiver ---142 A.3 Analysis of the static magnetic interference between adjacent transmitters ---146 REFERENCES ---161 ABSTRACT (KOREAN) ---176 ACKNOWLEDGEMENTS ---178Docto

(The) relationship of the lewis antigen expression between Helicobacter pylori and gastric mucosal tisses in gas

의학과/석사[한글] H. pylori 감염률이 높은 우리 나라에서 H. pylori감염이 확인된 환자의 위점막에서 배양한 H. pylori의 Lewis 항원 표현형과 위점막 조직의 Lewis 항원 표현형 및 Lewis 혈액형간의 연관성을 알아보고자 하였다. 1998년 9월부터 1999년 1월까지 연세대학교 의과대학 세브란스병원에서 상부 소화관 내시경검사를 시행하여 H. pylori 감염이 확인된 소화성 궤양 40예와 위암 18예, 비궤양성 위증 13예를 대상으로 생검한 위점막 조직과 생검된 조직에서 동정한 H. pylori, 그리고 환자의 Lewis 혈액형을 면역조직화학염색법, 효소면역 검사법, 혈구응집반응검사를 이용하여 각각 확인하였고 다음과 같은 결과를 얻었다. 1. Lewis 항원은 생검된 위점막 조직의 98.4%에서 발현하였으나, 위점막 조직의 Lewis 항원의 표현형과 위 십이지장 질환에 따른 연관성은 관찰되지 않았다. 2. 위점막 조직에서 동정한 H. pylori 균주의 33.9%인 20개에서 Le**x와 Le**y를 발현하였으며, 10개(16.9%)의 균주에서는 Le**x만을 발현하였고 16개(27.1%)의 균주에서는 Le**y만 발현하였다. 그리고 Le**x와 Le**y를 모두 발현하지 않은 균주는 13개(22.1%)였다. 질환에 따른 H. pylori 균주의 Le**y나 Le**x에 대한 흡광도의 차이는 없었지만, H. pylori 균주의 Le**x에 대한 Le**y의 흡광도의 비(Le**y/Le**x)를 보면 소화성 궤양군은 0.68±1.16, 위암군은 0.70±0.68로 비궤양성 위중군의 0.98± 1.57에 비해 각각 낮게 나타 났다. 3. 위 십이지장 질환 환자 20명에서 시행한 Lewis 혈액형의 표현형 빈도는Le(a-/b+)형이 50.0%, Le(a+/b-)형이 10.0%, 그리고 Le(a-/b-)형이 40.0%이었다. 4. Lewis혈액형과 동정된 H. pylori의 lewis 항원 표현형간의 상관관계를 보았을 때, H.pylori에서 Le**y가 Le**x보다 우세하게 표현된 경우는 Lewis 혈액형이 Le(a-/b+)형인 경우에 80.0%로 Le(a-/b+)형에서의 10.0%보다 의의있게 많았다. 이상의 결과를 종합하면, 위점막 조직과 위점막 조직에서 동정된 H. pylori 균주의 대부분에서 Lewis 항원이 발현되었으며, 숙주의 루이스 혈액형이 Le(a-/b+)형인 경우에서 Le(a-/b+)형보다 Le**y가 Le**x보다 우세하게 표현되었다. H. pylori와 관련된 위 십이지장 질환에서 Lewis 항원은 발병기전에 관여하는 병독인자의 하나로 생각되며, Lewis 항원이 위 십이지장 질환의 발병기전에 관여하는 과정은 H. pylori와 숙주의 상호관계라는 측면에서 연구되어야 할 것이다. [영문] Helicobacter pylori is regarded as a causative organism for chronic gastritis, peptic ulcer disease, and gastric cancer. The incidence and prevalence of H. pylori infection and gastric cancer is higher in Korea compared with those of western countries. I tried to determine the relationship between the expression of Lewis antigen of gastric mucosal tissues and that of clinically isolated H. pylori aquired from the patients with peptic ulcer disease, gastric cancer, and nonulcer dyspepsia. The gastric mucosal tissues and H. pylori strains were obtained from endoscopic biopsy specimens whitch were taken from 40 patients with peptic ulcer dosease, 18 patients with gastric cancer, and 13 patients with nonulcer dyspepsia. They visited the Severance Hospital, Yonsei University College of Medicine from September 1, 1998 to January 31, 1999. The Lewis antigen expression of gastric mucosal tissues was tested by immunohistochemical stain method, and that of H. pylori was tested by ELISA test 30 using monoclonal antibody for Le**x and Le**y, and Lewis phenotype of host RBC was by hemagglutinin test using monoclonal antibody for Le**a and Le**b. The results are as follows 1. Almost all the gastric mucosal tissues(98.4%) showed positive Le**x, Le**y or both antigenic expression. But there was no significant difference in Lewis antigen expression between each gstroduodenal diseases. 2. 20(33.9%) of 59 H. pylori isolates expressed both Le**x and Le**y, 10(16.9%) isolates produced only Le**x, 16(27.1%) isolates produced only Le**y, and 13(22.1%) isolates expressed none of Le**x and Le**y. The 0.D. value of bacterial Le**x and Le**y was not significantly different in relation to peptic ulcer disease, gastric cancer, and nonulcer dyspepsia. When the ratio of Le**y to Le**x(Le**y/Le**x) was compared according to the disease subtypes, patients with peptic ulcer disease and gastric cancer had lower OD value compared to the patients with nonulcer dyspepsia. 3. Twenty patients took blood tests at the time of endoscopic biopsy. 50.0% of the patients expressed Le(a-/b+) phenotype, 10.0% expressed Le(a+/b-) phenotype, and 40.0% expressed Le(a-/b-) phenotype. 4. The dominant expression of Le**y rather than Le**x by H. pylori as significantly more frequent in 80.0% of Le(a-/b+) phenotype than in 10.0% of Le(a+/b-) phenotype. In summary, Lewis antigen expression was significantly associated with both gastric mucosal tissues and H. pylori isolates from the patients with gastroduodenal diseases and dominant expression of Le**y H. pylori was significantly higher in Le(a-/b+)phenotype than in Le(a+/b-) phenotype. Lewis antigen is regarded as one of virulent factor of H. pylori in pathogenesis of gastroduodenal diseases. The possible mechanisms of pathogenesis in gastroduodenal diseases by Lewis antigen regarding the aspects of bacteria-host interaction should be farther investigated.ope

Cerulein 유발 급성 췌장염에 대한 Nafamostat mesilate의 예방 효과

학위논문(석사)--서울대학교 대학원 :협동과정 임상약리학전공,2006.학위논문(석사)-

(The)anti-cancer effect and its mechanism of combination of suberoylanilide hydroxamic acid (SAHA) and bortezomib with gemcitabine in pancreatic cancer cell lines

학위논문(박사) --서울대학교 대학원 :협동과정(임상약리학전공),2008. 8.Docto

한국어 비대격 동사의 어휘 의미론적 특징

학위논문(석사)--서울대학교 대학원 :언어학과,1998.Maste

A study on factors affecting intensity of newspaper article concerning to water environmental policy.

보건학과/박사ope

A Family of Molecular Sieves Containing Framework-Bound Organic Structure-Directing Agents

DoctorZeolites and related molecular sieves, with crystallographically well-defined channels and cavities of molecular dimensions, are not only extending their commercial uses as catalysts and separation media, but also finding new applications. To further improve their functional properties for expanded use, considerable efforts have been devoted over more than a decade to the synthesis of inorganic-organic hybrid materials with organic moieties incorporated into the inorganic framework. Indeed, if successful, new organic functionalities with tunable geometrical features can be introduced as catalytic and/or adsorption sites into the void spaces of this important class of crystalline, microporous materials. The strategies developed to date, in the search for such hybrid solids, involve either the direct synthesis using organosilanes containing organic functional groups as a (partial) silica source and alkylammonium-bound organosilanes as structure-directing agents, or the post-synthetic treatment using similar organosilane species as pillaring or silylating agents. Thus, they rely on the use of organic species which already contain an atom susceptible of incorporation as a tetrahedral atom in the zeolitic framework. In this study, we have reported the discovery of framework-bound organic structure-directing agent-containing molecular sieves (FOMSs) and a plausible formation pathway for this novel class of inorganic-organic hybrid crystals. Based on the study of FOMS, in addition, the first solid-solution of a zeolite and a FOMS has been demonstrated and their crystallization mechanism have been investigated. These studies can provide invaluable opportunities not only for extending our knowledge of many important aspects of the synthesis, structures, and modification of ordered microporous materials, but also for creating new applications. In the fourth part of this thesis, we demonstrate that ECR-40A, currently regarded as a typical silicoaluminophosphate (SAPO) molecular sieve synthesized using tris(2-hydroxyethyl)methylammonium ions with three OH groups, is a new family of inorganic-organic hybrid networks in which the organic structure-directing agent (OSDA) molecules employed in their synthesis are covalently bonded to the inorganic framework. In fact, OSDAs, such as quaternary ammonium cations and amines, used in the synthesis of zeolites and related crystalline microporous oxides usually end up entrapped inside the void spaces of the crystallized inorganic host lattice. But none of them is known to form direct chemical bonds to the framework of these industrially important catalysts and adsorbents. ECR-40A crystallization begins with the formation of an Al-OSDA complex in the liquid phase in which the Al is octahedrally coordinated. This unit is incorporated in the crystallizing ECR-40A. Subsequent removal of frameworkbound OSDAs generates Al-O-Al linkages in a fully tetrahedrally coordinated framework. In the fifth part of this thesis, we show that several members of the ECR-40 family are solid solutions of a zeolite and a FOMS than pure FOMSs. we have also analyzed a series of mother liquors and solid products separated as a function of time during the crystallization of ECR-40C, which has the largest zeolite portion (~ 60%) among the members of the ECR-40 family, using various characterization methods in order to understand the crystallization mechanism of zeolite-FOMS solid solutions. The structure of the as-made, hydrated form of ECR-40C, synthesized in the presence of (2-hydroxyethyl)trimethylammonium (HTMA+) ions as an OSDA and 2 wt% (of the alumina in the synthesis mixture) of aluminosilicate zeolite UZM-22 with the MEI topology as seeds, has been determined using synchrotron powder X-ray diffraction and Rietveld analyses. Two different types of organic species were suggested to exist in ECR-40C: the encapsulated HTMA+ ions with one intramolecular C–H•••O hydrogen bond, typical of OSDA molecules in as-made UZM-22, and the framework-bound cations. A combination of elemental and thermal analyses, Na+ ion exchange, and multinuclear MAS NMR and IR spectroscopies clearly shows the coexistence of the zeolite and FOMS domains with a proportion of approximately 3:2 in ECR-40C crystals. Na TEM elemental mapping reveals that the Na+ ions exchanged with the HTMA+ ions into as-made ECR-40C are uniformly distributed throughout the ECR-40C crystals. Therefore, ECR-40C is not a pure FOMS but a solid solution of a zeolite and a FOMS (i.e., UZM-22 and ECR-40-type FOMS), which has never been recognized or addressed before. The overall characterization results of this work demonstrate that the proportion of the zeolite domain in such solid-solutions varies notably with the number of OH groups in OSDAs