Circulating NK and T cell subpopulations correlate with response to immune checkpoint blockade in sarcoma patients

김수정 Graduate School, Yonsei University 2021 국내석사

Sarcomas are rare types of malignancies, and their median survival is 12 months despite classical treatment. Recently, PD-1/PD-L1 inhibitors have been proposed as a new potential therapy. However, due to their unsatisfactory clinical response, screening patients who may have a clinical benefit is essential. In this study, we performed immune cell profiling in sarcoma patient’s PBMCs before treatment with the immune checkpoint inhibitors nivolumab and durvalumab (n=17). A significantly higher percentage of CD3-CD56+NK cells was observed in PR compared to SD and PD at baseline. In addition, an increased proportion of PD-1 expressing CD4+T cells was associated with positive drug response. However, PD-1 expression in CD8+T cells did not seem to be associated with clinical outcome. Our results demonstrate that high proportions of NK cells and PD-1 expressing CD4+T cells observed at baseline are associated with better clinical outcomes, and can therefore represent predictive effectiveness in sarcoma patients. 육종암은 그간 고전적인 치료가 시도되었음에도 불구하고 생존 기간의 중간 값이 12개월 밖에 되지 않는 희귀 암종이다. 최근 PD-1/PD-L1 저해제가 가능성이 있는 새로운 치료제로 떠오르고 있다. 그러나 치료 효과가 항상 만족스럽지만은 않기 때문에 치료 전 어떤 환자가 임상적으로 좋은 결과를 얻을 수 있을지 선별하는 것이 중요하다. 이 연구에서는 면역관문 억제제인 니볼루맙과 더발루맙을 투약하기 전, 육종암 환자의 말초혈액 단핵구 세포를 분리하여 면역세포 프로파일링을 실시하였다. PD 환자군에 비하여 PR과 SD 환자군에서는 CD3-CD56+NK세포 비율이 상당히 높은 것으로 관찰되었고, CD4+T세포에서의 PD-1발현 또한 약제에 대한 반응성이 좋은 환자군에서 증가되어 있는 것으로 나타났다. 하지만 CD8+세포에서의 PD-1발현은 치료 결과와 연관성을 보이지 않았다. 이러한 결과는 치료 전 환자의 말초혈액에서 높은 NK세포의 비율과, CD4+세포에서의 증가된 PD-1발현이 더 좋은 치료 결과와 연관성이 있음을 보여주며, 이는 육종암 환자에서 효과적인 예측 바이오마커가 될 수 있음을 시사한다.

Isolation and composition analysis of Glycerogalactolipids from perilla (perilla frutescens (L.) britt.) leaf

이수정 Sookmyung Women's University 2020 국내석사

모노갈락토실디아실글글리세롤 (monoglactosyldiacylglycerols, MGDG)과 다이갈락토실디아실글리세롤 (digalactosyldiacylglycerols, DGDG)은 고등식물 등의 엽록체에 존재하는 글리세로갈락토지질 (glyceroglycolipids)의 주요 두 가지 형태이다. 식물에서 유래한 MGDG와 DGDG는 항종양, 항염증, 항암, 식욕억제 효과를 포함한 여러 가지 생리활성을 나타내는 것으로 알려져 있다. 본 연구의 목적은 깻잎에서 MGDG와 DGDG를 분리하고, 이들의 전체 지방산 조성 및 위치별 지방산 조성에서의 특징을 밝히는데 있다. 시금치, 파슬리, 깻잎을 포함한 3종의 엽채류를 클로로포름-메탄올 혼합액과 아세톤으로 각각 추출하여 6종의 추출물을 제조하였다. 동일 식물에서 클로로포름-메탄올 추출물의 MGDG와 DGDG의 수율이 아세톤 추출물의 수율 보다 높게 나타났으며, 이는 클로로포름-메탄올이 MGDG와 DGDG 회수에 보다 적합하다는 것을 의미한다. 클로로포름-메탄올 추출물 중 깻잎의 MGDG와 DGDG 함량은 각각 0.16 g/100 g과 0.04 g/100 g (원물 기준)으로 본 연구에서 사용된 3 종의 엽채류 중 가장 높은 총 MGDG, DGDG 함량을 보였다. 2단계 실리카 컬럼 크로마토그래피를 이용하여 깻잎의 클로로포름-메탄올 추출물로부터 고순도의 MGDG와 DGDG를 각각 ~97 g/100 g와 ~86 g/100 g의 순도로 정제하였다. 깻잎의 MGDG는 대부분 오메가-3 지방산인 18:3n-3 (~79 g/100 g)와 16:3n-3 (~12 g/100 g) 두 가지로 구성되어 있고, 16:3n-3의 경우 sn-2 위치에, 18:3n-3의 경우 sn-1 위치에 주로 존재하였다. DGDG의 경우, 18:3n-3 (~74 g/100 g)의 함량이 가장 높았고, 16:0 (~14 g/100 g)이 그 뒤를 이었으며, 16:0과 18:3n-3은 각각sn-2 위치와 sn-1 위치에 주로 존재하였다. 이러한 결과는 깻잎의 MGDG와 DGDG는 두 가지 합성 경로인 chloroplast pathway와 endoplasmic reticulum pathway를 모두 이용하여 합성된다는 점을 의미한다. Monogalactosyldiacylglycerols (MGDG) and digalactosyldiacylglycerols (DGDG) are two major types of glycerogalactolipids found in higher plants. MGDG and DGDG derived from plants have been shown to exert several biological activities including anti-tumor, anti-inflammatory, anti-cancer, and appetite-suppression effects. The aim of this study was to isolate MGDG and DGDG from perilla, and to investigate their total fatty acid composition and positional distribution pattern of fatty acids. Six different types of extracts were prepared from three kinds of leaf vegetables including perilla using chloroform/methanol (2:1, v/v) or acetone as extraction solvents. The yield of total MGDG and DGDG was significantly greater in chloroform/methanol extracts than in acetone extracts, thereby suggesting that chloroform/methanol is a better choice than acetone for the sufficient recovery of MGDG and DGDG from the leaf vegetables. Perilla containing the greatest total MGDG and DGDG content among the leaf vegetable samples used in this study contained 0.16 g/100 g MGDG and 0.04 g/100 g DGDG (on fresh weight basis). High purity of MGDG (~97 g/100 g) and DGDG (~86 g/100 g) can be prepared from the chloroform/methanol extracts of perilla, separately, by two-step silica column chromatography. The MGDG from perilla was mostly composed of the two omega-3 fatty acids, namely 18:3n-3 (~79 g/100 g) and 16:3n-3 (~12 g/100 g). The 16:3n-3 was predominantly located at the sn-2 position of MGDG and 18:3n-3 was mainly located at the sn-1 position. In DGDG, 18:3n-3 (~74 g/100 g) was the most abundant fatty acid followed by 16:0 (~14 g/100 g). The 16:0 and 18:3n-3 were predominantly located at the sn-2 and sn-1 positions of DGDG, respectively. Therefore, it is assumed that MGDG and DGDG in perilla are obtained via chloroplast pathway as well as endoplasmic reticulum pathway.

중소벤처기업의 기업가 지향성과 혁신행동 간의 관계 : 흡수역량의 매개효과와 사회적 자본의 조절효과

김수정 영남대학교 대학원 2026 국내석사

M.A. Thesis Entrepreneurial Orientation and Innovation Behavior in SMEs: The role of Absorptive Capacity and Social Capital Kim SuJeong Department of Business Administaration Graduate School Yeungnam University (Supervised by Prof. Park Taekyung) Abstract In a response to a dynamic and complex business environment, small and medium-sized enterprises (SMEs) seek to develop capabilities by leveraging their inherent resources to remain competitive. This research aims primarily to examine the relationship between entrepreneurial orientation and innovation behavior. Specifically, it investigates the mediating role of absorptive capacity and the moderating effect of social capital in this causal link. Drawing upon a systematic literature review of entrepreneurial orientation, absorptive capacity, social capital, and innovation behavior, hypotheses were developed and tested using data collected from a sample of 182 SMEs in South Korea. To assess the validity of the constructs, a confirmatory factor analysis was performed, and an internal consistency analysis was conducted to confirm the reliability of the measurement items. To test the hypotheses, a hierarchical regression analysis was carried out. The results show that entrepreneurial orientation is positively associated with absorptive capacity, which is related to innovation behavior. Thus, Hypotheses 1 and 2 are supported. The empirical findings also indicate that absorptive capacity plays a mediating role in the association between entrepreneurial orientation and innovation behavior, providing support for Hypothesis 3. Regarding the moderation hypotheses, internal social capital was found to play a negative moderating role in the link between entrepreneurial orientation and absorptive capacity, leading to the rejection of Hypothesis 4. In contrast, external social capital was found to have a positive moderating effect on the relationship as hypothesized, supporting Hypothesis 5. Theoretically, this study contributes to extending the framework of entrepreneurship research by incorporating absorptive capacity and the distinctive roles of social capital. It also advances the understanding of the significance of the two dimensions of social capital as moderators in the entrepreneurial orientation-absorptive capacity link. Practically, this research provides empirical evidence that strong entrepreneurial traits can strengthen a firm’s capability to monitor and obtain external resources, which serves as a solid foundation for innovative organizational behavior. It also implies that SME managers should strive to accumulate external social capital to further enhance their ability to identify and acquire external resources based on a high level of entrepreneurial orientation. Simultaneously, this suggests that efforts are also required to maintain internal networks and the strength of trust at a healthy level. Limitations of the research and suggestions for future studies are discussed.

Firth’s logistic regression for separation problem : Comparing between R-logistf and SAS-LOGISTIC

Sujeong Kim 연세대학교 일반대학원 2020 국내석사

The phenomenon of separation or monotone likelihood commonly occurs in fitting logistic regression model. Separation problems usually occur for small sample sizes with a highly imbalanced independent variable, or for large sample sizes with rare events. In this case the logistic regression model causes serious bias problem in the maximum likelihood (Firth D 1993, King, G. and Zeng, L 2001). To solve this bias, Firth proposed a penalized maximum likelihood estimation method. It produces finite parameter estimates with a simple modification of the score function. We can use the Firth’s method through several software packages such as R and SAS. But the motivating example showed differences in the output. For example, R-logistf and SAS-LOGISTIC gave different conclusions about the significance of variables even though they referred to the same Firth’s method paper (Heinze G, Schemper M 2002). Therefore the purpose of this study is to investigate the performance of Firth’s logistic regression in R (version 3.6.0) and SAS (version 9.4). We conducted a simulation study under various scenarios to compare standardized bias of estimates, mean standard error, coverage rate and convergence issue. According to the results of simulation study, in the case of separation problem caused by continuous variables, SAS has less bias of estimates and convergence problem than R. However in the case of separation problem caused by binomial variables, R and SAS has similar performance. Therefore we recommend using SAS software when analyzing Firth’s logistic regression.

Nanoscale composition tuning of Co-Ni hydroxide films for pseudocapacitor

Kim, Sujeong Sungkyunkwan university 2020 국내석사

This paper suggests the opportunity of enhanced electrochemical behavior through nanoscale composition tuning of cobalt-nickel hydroxide films using bottom-up synthesis of cobalt-nickel hydroxide nanosheets colloidal solutions and electrophoretic deposition (EPD) method. The cobalt-nickel hydroxide {(Co, Ni)(OH)2} nanosheets were synthesized in water/formamide solution with kinetically controlled diffusion of ammonia vapor. The composition tuning of (Co, Ni)(OH)2 {i.e. mixed-Co(OH)2 and Ni(OH)2, and mixed-(Co, Ni)(OH)2} films were accomplished by simply mixing of as-synthesized (Co, Ni)(OH)2 nanosheets colloidal solutions and EPD of the mixed solution. The cyclic voltammetry (CV) curve of the mixed-Co(OH)2 and Ni(OH)2 is embodied rather collective behavior of Co(OH)2 and Ni(OH)2 than (Co, Ni)(OH)2 thin film with a molar ratio of Co:Ni=5:5 however, going to be equal after 5000 cycles reaction. The CV curve of the mixed-(Co, Ni)(OH)2 film is comprehensive of the relative contributions from each (Co, Ni)(OH)2 nanosheets with the molar ratio of Co:Ni=10:0, 7:3, 4:6, and 2:8 films. 본 연구에서는 코발트-니켈 수산화물을 나노 단위에서 조성비에 변화를 줌으로서 슈도커패시터의 전기화학적 거동을 향상시키는 연구를 진행하였다. 코발트-니켈 수산화물 나노시트는 물/포름아미드 용액 상에서 암모니아 증기를 확산시켜줌으로써 콜로이드 용액으로 합성할 수 있었다. 합성된 코발트-니켈 수산화물 나노시트 콜로이드 용액을 단순히 섞어준 뒤, 이를 전기영동법으로 기판에 증착함으로써 코발트와 니켈의 조성비에 변화를 줄 수 있다. 순환 전류-전압법을 통해 전기화학적 특성을 확인한 결과, 코발트 수산화물과 니켈 수산화물 콜라이드 용액을 섞어서 제작한 mixed-Co(OH)2 and Ni(OH)2 양전극은 코발트 수산화물과 니켈 수산화물의 집합체로 확인되었으며 이는 코발트와 니켈의 비율이 5:5인 코발트-니켈 수산화물과 전혀 다른 전기화학적 거동을 나타낸다. 또한, 코발트와 니켈의 비율이 각각 10:0, 7:3, 4:6, 2:8인 코발트-니켈 수산화물 콜로이드 용액을 섞어서 제작한 mixed-(Co, Ni)(OH)2 양전극은 4개의 코발트-니켈 수산화물로부터 기인하는 다중의 산화 환원 반응이 관찰된다.

Sustainable Urban Agriculture and Its Impact to Human Health

김수정 Sujeong Kim 고려대학교 국제대학원 2016 국내석사

Abstract The purpose of this thesis is to figure out the way to build a sustainable urban agriculture to improve human health at this critical juncture that the world is facing the issue of food security. As one of responses to the improving human health, this thesis argues the importance of urban agriculture. To do that, first this thesis will analyze the impact of industrial urban agriculture to human health through Driving Force-Pressure-State-Exposure-Effect Action (DPSEEA) model. Then, it will analyze the case of Havana, Cuba; sub-Saharan Africa; some cities’ urban agriculture in the U.S; and Germany based on integrative conceptual framework with bearing in mind the Cost-Benefit Analysis (CBA) through which environmental, economic and social sustainability of urban agriculture will be assessed. Also, this thesis will find out some of limitations of UA. Lastly, it will discuss some of strategies for sustainable urban agriculture, which finally will contribute to human health promotion as well as food security.

Critical behaviors of the CI percolation on random networks

김수정 Korea University 2018 국내석사

Percolation on complex networks studies how the giant cluster of a network disappears under removing nodes or links. There are various strategies to select removing node, for instance, random failure, high-degree attack, PageRank(PR), k-core and Collective Influence(CI)-based attack, etc.\\ Here, we study among other things the so-called CI-based attack, or CI percolation, on random networks, which was introduced as a heuristic method for optimal percolation [Morone and Makse, Nature 524, 6568 (2015)]. The CI percolation is based on the value so-called ‘CI’, defined as CI$_{\ell}\left(i\right)=\left(k_{i}-1\right)\sum \limits_{j \in \partial B \left( i , \ell \right)}^{} \left(k_{j}-1\right)$, which incorporates both the degree of the node itself and its neighboring nodes at distance $\ell$. In CI percolation, the node having the largest value CI is called ‘top influencer’ and gets eliminated successively. As a result, the giant cluster collapses more quickly and suddenly, so that the percolation threshold becomes smaller than most of the other previously-studied strategies. We numerically investigate the critical behavior at the CI percolation transition. We estimate various critical exponent for $\ell$=1 and discuss the physical meaning of the obtained results.

Disinfection of bacteria inoculated on a Bacto-agar surface model using UVC-TiO2 photocatalytic reactor

김수정 Graduate School, Yonsei University 2014 국내석사

Firth's logistic regression for separation problem : comparing between R-logistf and SAS-LOGISTIC

김수정 Graduate School, Yonsei University 2020 국내석사

Removal of Cr(VI) from aqueous solution using poly(GMA-co-EGDMA)-graft-poly(allylamine)

김수정 Graduate School, Yonsei University 2018 국내석사

Chromium is used extensively in paint, ceramics, battery and glass manufacturing plants and electroplating, printing and photographic industries, etc. and is discharged into industrial wastewater. The wastewater is mainly present in the form of Cr(III) and Cr(VI). Cr(VI) is more toxic than Cr(III) due to its solubility and mobility characteristics. In particular, it causes toxicity to the respiration and skin of the organism and causes cancer. Thus, the technology for treating Cr(VI) from wastewater is highly required. Among many adsorbents, functionalized polymer adsorbents are easy to use, reusable and have excellent ion exchange capacity. It is also possible to graft various functional groups onto the surface of the adsorbent to increase the adsorption capacity. In this study, poly(GMA-co-EGDMA) was selected as the starting material of adsorbent to remove Cr(VI), and macroporous copolymer was synthesized by radical suspension copolymerization. The prepared copolymer has an epoxy group, and it has characteristics that it can react with various functional groups rapidly and be deformed. Poly(allylamine) was grafted on the synthesized copolymer to increase the adsorption amount and chemical stability of Cr(VI). The optimum condition was found by controlling the weight of allylamine. Then, functionalized adsorbents were prepared by using MITC. Amine group and thiourea group enable effective removal of Cr(VI). The polymer was analyzed by FT-IR spectroscopy, FE-SEM, mercury porosimetry, and BET and the chemical structure, surface morphology and pore characteristics of the polymer were confirmed. In addition, the adsorption amount of Cr(VI) solution according to pH, contact time, and initial concentration was confirmed to investigate the adsorption behavior. These were applied to kinetic models and adsorption isotherms to evaluate the adsorption capacity.