최소 S-보편성 판정 집합

학위논문(박사)--서울대학교 대학원 :자연과학대학 수리과학부,2020. 2. 오병권.For any set S of positive definite and integral quadratic forms with bounded rank, there is a finite subset S_{0} of S such that any S_{0}-universal quadratic form is also S-universal. Such a set S_{0} is called an S-universality criterion set. In this thesis, we introduce various properties on minimal S-universality criterion sets. When S is a subset of positive integers, we show that a minimal S-universality criterion set is unique. For higher rank cases, we prove that a minimal S-universality criterion set is not unique when S is the set of all quadratic forms of rank n with n≥9. We say a quadratic form f is recoverable if there is a minimal S_{f}-universality criterion set other than {f}, where S_{f} is the set of all subforms of f with same rank. We provide some necessary conditions, and some sufficient conditions for quadratic forms to be recoverable.변수의 개수가 유계인, 양의 정부호이고 정수 계수인 이차형식의 집합 S에 대하여, 모든 S_{0}-보편형식이 S-보편형식이 되는 S의 부분집합 S_{0}를 S-보편성 판정 집합이라 한다. 이 논문에서는 최소 S-보편성 판정 집합에 관한 다양한 성질에 관하여 연구한다. 먼저 집합 S가 자연수의 부분집합인 경우, 최소 S-보편성 판정 집합이 유일함을 증명한다. 또한, 9 이상의 정수 n에 대하여 모든 n차 이차형식의 집합을 S라 할 때, 최소 S-보편성 판정 집합은 항상 유일하지 않음을 증명한다. 이차형식 f의 모든 부분이차형식들의 집합 S_{f}에 대하여, {f} 이외의 최소 S_{f}-보편성 판정 집합이 존재할 때, f를 복구 가능한 이차형식이라 한다. 이 논문에서는 복구 가능한 이차형식이 되기 위한 몇 가지 충분조건과 몇 가지 필요조건을 증명한다.1. Introduction 1 2. Preliminaries 4 2.1 Quadratic spaces and lattices 4 2.2 Minkowski-reduced forms 8 2.3 Gluing theory 11 2.4 S-universality criterion sets 13 3. Uniqueness of minimal S-universality criterion sets 16 3.1 Rank 1 case 16 3.2 Higher rank cases 28 4 Recoverable -lattices 30 4.1 Some properties of recoverable -lattices 30 4.2 Recoverable binary -lattices 36 4.3 Recoverable numbers 41 Abstract (in Korean) 58Docto

Correlation Analysis and Prognostic Impact of (18)F-FDG PET and Excision Repair Cross-Complementation Group 1 (ERCC-1) Expression in Non-Small Cell Lung Cancer

PURPOSE: The aim of this study was to determine the relationship between [(18)]-2-fluoro-2-deoxy-D-glucose (FDG) uptake and excision repair cross-complementation group 1 (ERCC-1) expression and to evaluate the prognostic effect of these two factors in resectable non-small cell lung cancer (NSCLC) patients. METHODS: We retrospectively reviewed 212 patients with resectable NSCLC who underwent FDG positron emission tomography/computed tomography (PET/CT) scan for cancer staging and ERCC-1 expression analysis between January 2008 to December 2011. All patients were then followed-up for survival analysis. Semiquantitative evaluation of ERCC-1 was performed with the H-scoring system and was correlated with maximum standardized uptake value (SUVmax) of NSCLC. Univariate and multivariate analyses were performed to evaluate for FDG uptake and ERCC-1 expression predicting overall survival. RESULTS: In 212 patients (139 male, median age 68 ± 9.11), 112 patients had ERCC-positive tumors and 100 patients had ERCC-negative tumors. There was no significant difference in SUVmax between ERCC-1-positive tumors (8.02 ± 5.40) and ERCC-1-negative tumors (7.57 ± 6.56, p = 0.584). All patients were followed-up for a median of 40.5 months (95 % confidence interval [CI], 38.5-42.2 months). Univariate analysis and multivariate analysis for all patients showed that both ERCC-1 expression (hazard ratio [HR], 2.78; 95 % CI, 1.20-6.47) and FDG uptake (HR, 4.50; 95 % CI, 2.07-9.77) independently predicted overall survival. CONCLUSIONS: We have found no statistical correlation between FDG uptake and ERCC-1 expression in NSCLC. However, both higher FDG uptake and positive ERCC-1 expression are independent predictive markers of prognosis, suggesting that both should be obtained during patient workup.ope

A Study on Radio Propagation Environment for Digital Broadcasting in Busan Area

Recently, the trends of broadcasting technology are transformed analog broadcasting to digital broadcasting. This is the why digital broadcasting technology offers multimedia services such as home shopping or home banking, internet searching, telecommunication, VOD etc. Therefore, it is necessary to analyze radio propagation environment of digital broadcasting service area. However, it is very difficult to apply the conventional propagation models for Busan urban area where are a lot of mountain and hill. Among the conventional propagation models, ETRI propagation model is very optimal for analyzing the radio propagation environment in Busan area. This thesis is analyzed geographical propagation characteristics with ETRI propagation model and is measured the field strength for digital broadcasting at UHF band. Finally, this thesis is compares simulation values based on ETRI propagation model with measured values, and analyzes radio propagation environment. This thesis suggests suitable radio propagation model in Busan urban area.제 1 장 서 론 1 제 2 장 전계강도 이론 3 제 3 장 여러 가지 전파모델 5 3.1 Okumura-hata 모델 6 3.2 Lee 모델 8 3.3 Bertoni - Walfisch(COST-231) 모델 10 3.4 Ibrahim-Parsons 모델 12 3.5 Carey 모델 14 3.6 Egli 모델 15 3.7 Longley-Rice 모델 16 제 4 장 적용전파모델과 실측치 비교 17 4.1 적용전파 모델 17 4.2 기본전계강도 18 4.3 지역별 수신안테나 높이 보정항 19 4.4 회절손실 20 4.5 전파환경 분석을 위한 파라미터 22 제 5 장 전계강도 측정 및 분석 24 5.1 전계강도 측정환경 24 5.2 전계강도 분석 26 5.3 시뮬레이션을 통한 전계강도 분석 31 제 6 장 결론 38 참고문헌 3

Signal Transduction by Cell Adhesion Receptors, Integrins

Interactions of cells with basement membranes and the extracellular matrices are crucial for various biological processes, including the maintenance of tissue integrity, embryogenesis, wound healing, and the metastasis of tumor cells. These processes involve cell adhesion and migration. Adhesive and migratory events require certain biochemical entities, formation of multiprotein complex between these entities, and their functional communication one another. Cell adhesion is mediated through cell adhesion receptors or transmembrane glycoproteins binding to extracellular matrix (ECM) or counterreceptors on neighbor cells. Cell adhesion receptor families include cadherins, selectins, syndecans, and the immunoglobulin superfamily of cell adhesion molecules (IgCAMs). In this review, integrin-mediated cellular processes such as cell proliferation and apoptosis and their molecular basis will be discussed based on recent observations, although other cell adhesion receptors can play important roles or be involved in the processes and recent outstanding reviews are also availableOAIID:oai:osos.snu.ac.kr:snu2003-01/102/0000003910/2SEQ:2PERF_CD:SNU2003-01EVAL_ITEM_CD:102USER_ID:0000003910ADJUST_YN:NEMP_ID:A078142DEPT_CD:375CITE_RATE:0FILENAME:논단_review.pdfDEPT_NM:약학과EMAIL:[email protected]:

Prognostic Significance of Volume-Based FDG PET/CT Parameters in Patients with Locally Advanced Pancreatic Cancer Treated with Chemoradiation Therapy

PURPOSE: We investigated the prognostic role of volume-based parameters measured on 18F-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) scans in patients with locally advanced pancreatic cancer (LAPC) treated with chemoradiation therapy (CRT). MATERIALS AND METHODS: We enrolled 60 patients with LAPC who underwent FDG PET/CT before CRT. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary pancreatic cancers were measured on FDG PET/CT scans. Treatment response was evaluated according to the Response Evaluation Criteria in Solid Tumors. Survival analysis was performed using the Kaplan-Meier method, and Cox proportional hazard models were used to determine independent prognostic factors. RESULTS: The progression-free survival (PFS), locoregional progression-free survival (LRFPS), and overall survival (OS) for this population were 6.2, 10.9, and 13.2 months, respectively. The overall treatment response rate was 16.7% at 4 weeks after CRT, and the disease control rate (DCR) was 80.0%. DCR was significantly higher in patients with low SUVmax, MTV, or TLG, and showed strong correlation with longer survival times. On univariate analysis, MTV and TLG were significant prognostic factors for PFS, LRPFS, and OS, together with pre-CRT and post-CRT CA19-9 levels. Multivariate analyses demonstrated that MTV together with the pre-CRT CA19-9 level were independent prognostic factors for PFS, LRPFS, and OS, as was TLG for LRPFS and OS. CONCLUSION: MTV and the pre-CRT CA19-9 level provided independent prognostic information in patients with LAPC treated with CRT. Volume-based PET/CT parameters may be useful in identifying which subgroup of patients would benefit from radiation therapy as a part of CRT.ope

The COOH-terminus of TM4SF5 in hepatoma cell lines regulates c-Src to form invasive protrusions via EGFR Tyr845 phosphorylation

AbstractTransmembrane 4 L six family member 5 (TM4SF5) enhances cell migration and invasion, although how TM4SF5 mechanistically mediates these effects remains unknown. In the study, during efforts to understand TM4SF5-mediated signal transduction, TM4SF5 was shown to bind c-Src and thus hepatoma cell lines expressing TM4SF5 were analyzed for the significance of the interaction in cell invasion. The C-terminus of TM4SF5 bound both inactive c-Src that might be sequestered to certain cellular areas and active c-Src that might form invasive protrusions. Wildtype (WT) TM4SF5 expression enhanced migration and invasive protrusion formation in a c-Src-dependent manner, compared with TM4SF5-null control hepatoma cell lines. However, tailless TM4SF5ΔC cells were more efficient than WT TM4SF5 cells, suggesting a negative regulatory role by the C-terminus. TM4SF5 WT- or TM4SF5ΔC-mediated formation of invasive protrusions was dependent or independent on serum or epidermal growth factor treatment, respectively, although they both were dependent on c-Src. The c-Src activity of TM4SF5 WT- or TM4SF5ΔC-expressing cells correlated with enhanced Tyr845 phosphorylation of epidermal growth factor receptor. Y845F EGFR mutation abolished the TM4SF5-mediated invasive protrusions, but not c-Src phosphorylation. Our findings demonstrate that TM4SF5 modulates c-Src activity during TM4SF5-mediated invasion through a TM4SF5/c-Src/EGFR signaling pathway, differentially along the leading protrusive edges of an invasive cancer cell

Regulation of TM4SF5-mediated tumorigenesis through induction of cell detachment and death by tiarellic acid

mRNA for four-transmembrane L6 family member 5 (TM4SF5), a homolog of tumor antigen L6, was previously shown to be highly expressed in diverse tumors. We recently found that human hepatocarcinoma tissues also overexpressed TM4SF5 protein, in comparison to normal liver tissues.We also found that tiarellic acid (TA) caused cell detachment-related apoptosis in cells expressing endogenous or stably-overexpressing TM4SF5. When cells expressing TM4SF5 were treated with TA, we observed reduced phosphorylation of focal adhesion kinase, paxillin, and p130Cas, but not c-Src. TA treatment also caused focal adhesion loss and reduced cell adhesion, and increased the numbers of floating cells and apoptotic cells. These effects were blocked by overexpression of focal adhesion molecules, suggesting that treatment with TA mediates anoikis of TM4SF5-expressing cells. However, TM4SF5-null cells were not affected by TA, indicating that these effects occur specifically in TM4SF5-positive cells. TA administration reduced tumor formation in nude mice injected with TM4SF5-expressing cells, presumably through increased apoptosis in TM4SF5-positive tumors. These observations indicate that TM4SF5-positive tumorigenesis can be inhibited by TA via induction of cell detachment-related apoptosis, and suggest that TA may be developed as a putative therapeutic reagent against TM4SF5-positive tumorigenesis

X-band 4-bit FET Phase Shifter Using Characteristic Impedance Transformation

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