Distributed Methods for Large-Scale Optimization, Learning, and Games

Nguyen, Duong Thuy Anh Arizona State University ProQuest Dissertations & 2025 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The proliferation of large-scale networked multi-agent systems has necessitated the development of distributed methods especially when centralized solutions are impractical due to constraints on communication, computation, or privacy. This dissertation develops novel distributed methods for optimization, learning, and Nash equilibrium seeking in multi-agent systems, with a particular emphasis on addressing time-varying directed communication networks—one of the most challenging and largely unresolved problems in the field. Existing literature predominantly focuses on static, bidirectional or weight-balanced networks, as analyzing time-varying asymmetric information flows presents significant theoretical difficulties. However, time-varying directed communication networks are fundamental to many critical applications, including autonomous systems, sensor networks, and federated learning, where communication links frequently change due to mobility, bandwidth fluctuations, failures, or heterogeneous transmission capabilities.This dissertation provides a rigorous and comprehensive framework for handling time-varying directed information flows, introducing novel consensus-based algorithmic solutions and convergence analyses that overcome these long-standing theoretical and practical barriers. A key contribution is the development of two novel contraction properties that redefine convergence analysis and stability guarantees for distributed algorithms in time-varying directed networks. These contraction relations rigorously characterize the information exchange process governed by the pulling and pushing mechanisms through row-stochastic and column-stochastic weight matrices, providing explicit learning rate conditions and convergence bounds directly in terms of communication connectivity and problem-specific properties.

(An) analysis of the hydrogen absorption process via palladium hybrid porous aluminum oxide to re-visit the cold fusion

Nguyen, Duc Hieu Sungkyunkwan University 2022 국내석사

For decades, the term “nuclear fusion” has been familiar among scientists; for those who might be unfamiliar with the phrase “nuclear fusion,” it is a reaction involving at least two atomic nuclei fuse to produce a heavier core with the release of energy, which is the principal reactions that power the Sun and other Stars. Once the nuclear reaction is triggered, it will maintain the reaction itself until it runs out of atoms; however, the fusion reactions only happen at extremely high temperatures and pressure, making them exceptionally difficult to trigger in vitro and impossible to regulate the reaction. Then nearly thirty years ago, in 1989, two chemists Martin Fleischmann and Stanley Pons, while researching the electrochemistry phenomenon of Palladium (Pd) in heavy water, reported that their apparatus had produced an unnatural amount of excess heat of a magnitude they asserted would defy explanation in terms of nuclear processes. It can only be explained by applying the hypothesized nuclear reaction type, called “Cold Fusion.” It is demonstrated that the nuclear reaction would occur at or near the temperature room. However, despite the efforts of many other scientists who tried to replicate the experiment, many have failed; to date, no successful replication has been found. A few groups have begun to re-examine the Cold Fusion issue in recent years; many are actively involved in the controversial field of Low Energy Nuclear Reactions (LENR). LENR researchers are attempting to perform experiments that closely replicate the setup in the original Pons-Fleischmann experiment. We were motivated to write this thesis by the Nature publication released in 2019 that re-visited the cold fusion argument and called for action on the subject. We decided to re-visit cold fusion using a new approach based on our expertise in the materials field. This study adopted an alternate technique to produce chemical-free, evenly dispersed Palladium nanoparticles hybrid Conventional Porous Anodic Aluminum Oxide (Pd-NP/AAO) to attempt cold fusion using the nanomaterials. Pd-NP/AAO was used in this work to evaluate the hydrogen absorption and desorption characteristics of Hydrogen and the practicality of the proposed approach, among other things.

생물공학응용을 위한 졸-겔 기반 광학센서 및 양자점 프로브에 관한 연구

Hong, Dinh Duong 전남대학교 대학원 2007 국내박사

Enzyme glucose oxidase (GOD) was immobilized on the sol-gel films of 3-glycidoxypropyltrimethoxysilane (GPTMS) and its mixtures with methyltriethoxysilane (MTES) and 3-aminopropyltrimethoxysilane (APTMS) to evaluate the ability of these sol-gels for enzyme immobilization. The film containing GPTMS (20v/v%) and APTMS (5v/v%) was an excellent membrane for enzyme immobilization in term of high enzyme activity and stability. Ruthenium diphenylphenanthroline complex, a highly fluorescent and photostable dye, is embedded in several sol-gel films (GA1, GA2, GM1, GM2) to produce the oxygen sensing films. The films were prepared in situ on the bottom of the wells of the 96 well microtiter plate. The prepared plate was employed as micro bioreactor for Escherichia coli JM 109 cultivation. The oxygen consumed by E.coli was measured by the oxygen sensing membranes. All sensing membranes are sensitive to the change in oxygen concentration, the membrane used sol-gel GM2 (12.5 v/v% of GPTMS and 25v/v% of MTES) showed the highest ability. Based on the above results the optical planar biosensors for detection of glucose, lactate and tyramine using the microtiter plate were developed. The enzymes (glucose oxidase, lactate oxidase, tyramine oxidase) were immobilized on the sol-gel GPTMS and the sol-gel mixtures of GPTMS and MTES or GPTMS andAPTMS. The oxygen sensitive dye, ruthenium complex, was entrapped in sol-gel mixtures of GPTMS and MTES. The linear detection ranges of these sensing membranes were of 0.1-5.0 g/L for glucose, 7.77-90 mg/L for lactate and 6.3-100 mg/L for tyramine. The covalent binding of the enzymes in the sol-gel films preserved the high stability of the sensing membranes for more than 10 months. The pH indicator, fluoresceinamine isomer II, was immobilized in the solgel matrix made by two precursors, MTES and GPTMS to produce the optical pH sensor. The immobilization process was carried out in one simple step of the covalent binding between GPTMS and fluoresceinamine. The suitable combination of two precursors, GPTMS and MTES, was a favor support matrix of fluoresceinamine, and showed the high sensitivity with the extension of pH detection range up to 4-10. The linear range was from pH 6 to pH 9 (R² = 0.995). Optical temperature sensors were prepared using a fluorescent dye, rhodamine B, and different adsorbents, viz. silica gel and sol-gel. Silica gel (28-200 mesh) and a sol-gel consisting of a mixture of APTMS and GPTMS were used as the support matrices for the fluorescent dye. The linear detection ranges of the fiber optic temperature sensors were 10-95 ℃ and 0-60 ℃ when using silica gel and sol-gel respectively as the support materials. The planar optic temperature sensors showed high sensitivity in the temperature range of 25-40 ℃. The life time of the sensors was extended more than 3 months. CdSe/ZnS core/shell quantum dots (QDs) were synthesized with different emission wavelength 590-620nm. QDs (590nm) were conjugated with enzyme glucose oxidase (GOD) and horseradish peroxidase (HRP). The complex of GOD/HRP-conjugated QDs was used as quantum dot FRET-based probes in sensing glucose. The quenching of QD fluorescence was corresponding to glucose concentration. Linear detection range of using enzymes-conjugated QDs in glucose solutions was of 0-5 g/L (R = 0.992). Anti-insulin antibody was labeled by water soluble CdSe/ZnS QDs (605nm) and used for insulin detection. The conjugation of quantum dots and antibody was performed directly or indirectly through streptavidin and biotinylated second anti insulin antibody. The direct conjugation showed linear detection range of 0.2-8.0 μM, (R=0.988), whereas, the indirect conjugation indicated linear detection range of 0.2-10 μM (R=0.977) and signal clearly separated at insulin concentrations of 0.2-1.0 μM after 1.5 hours of initial measurements.

Material characterization and electrochemical catalytic application of two dimensional molybdenum ditelluride

Seok, Jinbong Sungkyunkwan University 2022 국내박사

Recently, Two-dimensional TMD materials are being studied in various applications because of their unique material properties. Among them, electrochemical catalyst for hydrogen evolution reaction has been also being actively studied for producing clean and renewable hydrogen energy source to replace fossil fuel energy like coal and oil. In this study, we report an effective and stable HER at atomically defined reaction sites in 2D layered semimetallic MoTe2 with intrinsic turnover frequency (TOF) of 0.14 s−1 at 0 mV overpotential, which cannot be explained by the traditional volcano plot analysis. Hydrogen adsorption, the rate-determining step of the HER on the semimetallic MoTe2, enhances the HER, unexpectedly. Which is caused by Peierls-type lattice distortion that, together with a surface charge density wave. It is different with former electrochemical catalysts. And more, we report a hybrid catalyst with monoclinic MoTe2 and platinum (Pt) for the HER. Pt atoms were chemically bound to the surface of monoclinic MoTe2 that has an atomically distorted lattice structure, which produces a distinct Pt-Te alloy layer. The Pt/MoTe2 hybrid catalyst exhibits an active HER with a Tafel slope of 22 mV per decade and an exchange current density of 1.0 mA/cm2, which are the best values among those reported for TMD-based catalysts. Last, in order to make a more economical and mass-produced catalyst, MoTe2 and carbon nano tube (CNT) nanocomposite was synthesized using a hydrothermal process. This catalyst shows 30% more increased electrochemical catalytic behavior than pristine MoTe¬2. This works will help to make a more efficient catalyst for hydrogen evolution reaction for hydrogen energy in the future. 2차원 TMD(Transition metal dichalcogenide) 물질은 그가 가진 특별한 물성 때문에, 다양한 방면에서 연구가 이뤄지고 있다. 그 중, 전기화학적인 물분해반응을 이용한 수소 발생반응(Hydrogen evolution reaction)의 촉매로의 응용연구 또한 활발히 진행되고 있는 중이다. 2차원 TMD 물질 중, MoTe2는 구조가 변함에 따라 상(phase)이 바뀌고, 전자 구조가 달라지며, 이에 따라 전기적 특성이 반도체와 메탈로 변화하는 성질을 가지고있다. 이러한 성질을 이용하여, 우리는 이 논문에서 불문해 수소발생반응의 촉매로써 MoTe2를 사용하여 물질의 기본적 특성을 분석하고, 반응 메커니즘을 이해한 뒤, 이를 더 실용적으로 발전시키는 방법에 대해 연구하였다. 첫번째로, 단결정 MoTe2의 물질적 특성을 평가하여 그 상에 따른 촉매 발생 효율을 비교하였고, STM과 밀도 함수 이론(DFT) 계산을 이용하여 촉매 발생 반응 점 및 메커니즘을 연구하였다. 그 결과 1T’-MoTe2 는 intrinsic turnover frequency (TOF)가 0mV에서 0.14 s−1 의 높은 값을 가지는 것을 밝혔고, 가장자리(edge)가 아닌 표면(basal plane)에서의 반응이 더욱 활발하다는 것을 알게 되었다. 그것은 1T’-MoTe2 의 Lattice distortion으로 인한 물질 표면에 charge density wave를 가지는 특별한 구조 때문에 전자의 응집이 표면에 더욱 이루어져 생겨났다는 사실을 밝혀냈다. 두번째로, 해당 물질의 촉매 효율을 높이기위하여, 표면에 백금을 전기화학적으로 증착하는 방법을 통해, 백금 촉매를 이용한 촉매 활성도를 조절하는 연구를 진행하였다. 그렇게 합성된 Pt/1T-MoTe2의 경우, 최대 22 mV per decade 의 Tafel slope 값과 1.0 mA/cm2 의 교환전류밀도(exchange current density) 값을 가짐을 보고하였다. 이는 기존 TMD based 촉매 물질 중 가장 높은 수치이다. 그리고 DFT 계산을 이용하여, 백금 합성 촉매가 가장 효율이 높은 합성 비율을 계산할 수 있었고, 이는 비싼 백금의 사용을 효율적으로 조절 할 수 있는 단서를 제공하였다. 세번째로, 좀 더 경제적이고 대량생산이 가능한 촉매를 만들기 위해, 수열합성법(hydrothermal process)를 이용하여 MoTe2 와 탄소나노튜브(CNT)를 합성한 나노 복합체를 개발하고, 그 촉매 효율을 높이는 방법을 연구하였다. 이를 통해 기존 MoTe2에 비해 CNT를 합성한 나노 복합체 촉매는 약 30% 더 높은 촉매 효율을 얻을 수 있었다. 이는 앞으로 주목받고 있는 소수 에너지 활용을 위한 수소생산반응을 이해하고 좀 더 효율적이고 경제적인 촉매를 만드는데 도움이 될 것이다.

Development of liquid crystal-based sensing platforms for real-time detection of biomolecules and environmental contaminants

Duong, Song Thai Duong Gachon University 2025 국내박사

This dissertation presents research work dealing with rapid diagnostic methods for the monitoring of biomolecules and environmental contaminants through the use of liquid crystal (LC)-based sensing technology. The inherent elasticity of LC enables the amplification of slight changes in surface anchoring at the interface between the LC sensor and the target biomolecule, which facilitates optical detection using polarized optical microscopy (POM). Chapter 1 introduces the concept of biosensors, with a particular focus on LC-based biosensors and the properties of LC materials. A biosensor is defined as an analytical instrument consisting of components including: receptor, transducer, and signal processor, which together provide increased sensitivity and reliability. LC-based sensors detect analytes through observable optical changes, making them an effective tool for examination environmental, early diagnosis due to their simplicity and cost-effectiveness. Liquid crystalline materials can exist in different phases, transitioning between ordered and disordered states, and are categorized into thermotropic and lyotropic types. Birefringence, a key property of LCs, enables the study of optical variations in response to molecular ordering. Chapter 2 presents an LC-based assay for quantification sialic acid (SA). The sensor machenism is based on a synthetic bimetallic Co/2Fe MOF mimicking an oxidase and the NANA aldolase. After functionalization on TEM gold grids, the free SA was converted to pyruvate and N-acetyl-D- mannosamine in an aqueous solution by the catalysis of NANA aldolase. The subsequent Co/2Fe MOF-mediated reaction converts pyruvate to acetyl phosphate and H2O2, resulting in a sharp change in pH. This pH change is optically detected using LC doped with stearic acid. Chapter 3 presents a sensor that utilizes the electrostatic interactions between Cu²⁺ ions and DOPG molecules to detect glyphosate. The effectiveness of the sensor was qualitatively and quantitatively validated, with applications for environmental monitoring and agriculture investigated. Chapter 4 presents a qualitative detection method for phosphatidylserine (PS) using a waveform surface modification in conjunction with an Annexin V amplification system. The presence of annexin V contributed to enhance the optical signal, which significantly influenced mobilization of LCs and correlated with the changes in surface roughness. The sensor effectively detects PS by recognizing shifts in LC alignment. In chapter 5, an aptasensor was introduced with the aim to monitor acetamipride (ACE) using aptamers. ACE-antibody binding induces surface topography changes, resulting on potential repositioning of the LCs and changes in the optical signals. The observed optical intensities correlate with the ACE concentrations and allow a quantitative analysis of ACE in different samples.

Real-time and Label Free Detection of Biochemical Reaction Using Liquid Crystals

DUONG SONG THAI DUONG Gachon University 2021 국내석사

In this thesis, we describe the research of nematic liquid crystals (LCs)-based sensing technology to monitor biochemical reactions by investigating the optical response of LCs. Biochemical reactions could be sensitively detected with a polarizing light microscope due to the birefringence as well as the long-range anchoring transition of LCs. Herein, we observed the orientational transition of LCs influenced by (i) the enzymatic reactions of Human arginase 1 and ʟ-Arginine, and (ii) the biomolecular interactions of MUC1 and its specific aptamer. In (i) system, stearic acid is doped with 5CB to form a pH-dependent LCs. ʟ-arginine were hydrolyzed in the catalysis of ARG1 leading to the increase in pH. Then, stearic acid is deprotonated and adsorbed at the interface and change the LCs orientation. The shift on the LC alignment could be identified by an optical signal by using a polarizing light microscope. In (ii) system, the alignment molecules and bioreceptor are co-immobilized on the glass surface. While the alignment molecules anchor nematic LCs, bioreceptor capture the target. The surface topography changes and leads to the disrupt of LCs anchoring. The change in the LCs orientational could be observed by using a crossed polarizers. We described the LC-based sensing systems as a real-time and sensitive technique for imaging biochemical reactions.

Crosstalk between glutathione peroxidase-1 gene and protein kinase Cδ gene in the methamphetamine-induced dopaminergic neurotoxicity

DUONG XUAN CHU 강원대학교 2008 국내박사

Escalating evidences suggest that oxidative stress is involved in methamphetamine (MA)-induced neurotoxicity, and that peroxides including H2O2 play a crucial role in this toxicity. Enzymatic antioxidants, such as catalase, and glutathione peroxidase (GPx), provide a first line of defense against H2O2. A selenium-dependent GPx (GPx-1) out of GPx isozymes is considered as a major H2O2 scavenger in the brain. In the present study, it was asked whether GPx-1 gene affects MA-induced dopaminergic neurotoxicity, and whether protein kinase C (PKC) affects this toxicity, since it was suggested that PKC might contribute to dopaminergic toxicity. Treatment with MA (8.0 mg/kg, i.p. x 4) resulted in the decrease in striatal GPx-1-like immunoreactivity in the GPx-1 (+/+) mice. MA treatment produced hyperthermia, dopaminergic toxicity [as measured by dopamine turnover rate, tyrosine hydroxylase (TH) activity, TH-like immunoreactivity and TH phosphorylation at serine residue 31, 40], oxidative stress [as measured by protein carbonyl and lipid peroxidation], neuroinflammation [as measured by cyclooxygenase-2 (COX-2)-, interleukin-6 (IL-6)-, tumor necrosis factor-α (TNF-α)-, and interferon-γ (IFN-γ)-like immunoreactivity], microgliosis [as labeled by F4/80- or ionized calcium-binding adaptor molecule-1 (Iba-1)-like immunoreactivity], and reduction of neurotrophic factors [as measured by brain-derived neurotrophic factor (BDNF)- and glial cell line-derived neurotrophic factor (GDNF)-like immunoreactivity]. Intrastriatal microinjection with chelerythrine (a pan-inhibitor of PKC) or rottlerin (an inhibitor of PKCδ), but not with Go6976 (a co-inhibitor of PKCα and PKCβ), hispidine (an inhibitor of PKCβ) or PKCζ pseudosubstrate (an inhibitor of PKCζ), attenuated MA-induced hyperthermia and behavioral impairments (as measured by locomotor activity and rota-rod performance). Consistently, treatment with MA significantly increased striatal expressions of PKCδ and cleaved PKCδ, whereas there was no significant change in the expressions of other PKC isozymes. These findings were more pronounced in GPx1 (-/-) mice than GPx1 (+/+) mice. Intrastriatal microinjection with chelerythrine or rottlerin significantly attenuated MA-induced increases in the PKCδ and cleaved PKCδ. As shown in case of chelerythrine or rottlerin, GPx-mimics, such as ebselen and acetylsalicylic acid maltol ester (AME), significantly attenuated MA-induced hyperthermia, behavioural impairments, dopaminergic toxicity, oxidative stress, neuroinflammation, microgliosis, increased striatal expressions of PKCδ and cleaved PKCδ, and decreased expressions of neurotrophic factors. In addition, treatment with ebselen, AME or rottlerin significantly prevented MA-induced decreases in mouse double minute (MDM)-2 phosphorylation as well as increases in p53 expression in the striatum of the mice. The protective effects of ebselen, AME or rottlerin were less pronounced in GPx-1 (-/-) mice than GPx-1 (+/+) mice. GPx-1-like immunoreactivity was restored by intrastriatal GPx-1 gene transfection with GPx1 gene-encoded adenovirus vector in GPx1 (-/-) mice. Intrastriatal GPx-1-transfected GPx1 (-/-) mice were less susceptible to MA-induced hyperthermia, behavioural impairment, decrease in TH-like immunoreactivity, and increase in PKCδ expression as compared with those of control vector-transfected GPx1 (-/-) mice. In addition, MA-induced hyperthermia, behavioural impairment, increase in dopamine turnover rate, decrease in GPx-1 expression were less pronounced in PKCδ (-/-) mice than PKCδ (+/+) mice. The results suggest that GPx1 gene is an essential factor for blocking MA-induced dopaminergic toxicity, and that PKCδ gene is involved in this pathogenesis. GPx-mimic compounds attenuate MA neurotoxicity via inhibiting PKCδ expression, oxidative stress, and neuroinflammation. 지금까지의 많은 연구결과들이 oxidative stress가 메탐페타민 (MA)에 의한 신경독성에 관여함을 제시하고 있으며, 특히 H2O2를 비롯한 과산화물이 결정적인 작용을 수행함. Catalase 혹은 glutathione peroxidase (GPx)와 같은 항산화 효소들이 H2O2를 일차적으로 소거하는데, 그 중에서도 셀레늄 의존형 GPx (GPx-1)가 중추신경계의 가장 주요한 H2O2 소거 효소 중 하나임. 이번 연구에서는 GPx-1 유전자가 MA에 의한 도파민성 신경독성에 어떠한 역할을 수행하는지 규명하였으며, protein kinase C (PKC)가 도파민성 신경독성 과정에 관여한다는 보고가 있었기 때문에, MA에 의한 독성에서 PKC 유전자의 역할에 대한 연구도 이루어졌음. MA (8.0 mg/kg, i.p. x 4)를 투여한 GPx-1 (+/+) 생쥐의 선조체에서 GPx-1 면역활성의 감소가 관찰되었음. MA 투여는 고체온증, 도파민성 독성 [도파민 회전율의 증가, tyrosine hydroxylase (TH)의 활성 및 발현, TH serine 31번 및 40번 잔기의 인산화의 감소], oxidative stress (단백질 산화와 지질과산화의 증가), 신경염증성 반응 (cyclooxygenase-2, interleukin-6, interferon-γ, tumor necrosis factor-α의 변화), 소교세포 활성화 (F4/80- 혹은 ionized calcium-binding adaptor molecule-1-면역활성의 증가) 및 신경성장 인자의 감소 (brain-derived neurotrophic factor- 및 glial cell line-derived neurotrophic factor-면역활성의 감소)를 유도하였음. Chelerythrine (PKC 억제제) 혹은 rottlerin (PKCδ 억제제)의 선조체 내 투여는 MA에 의한 고체온증과 행동이상 (자발운동량의 감소 및 rota-rod test에서의 수행능력 저하)을 유의하게 감소시킨 반면, Go6976 (PKCα와 PKCβ의 동시 억제제), hispidine (PKCβ 억제제), 혹은 PKCζ pseudosubstrate (PKCζ 억제제)의 투여는 유의한 효과를 나타내지 않았음. 이와 마찬가지로, MA 투여 후에 선조체에서 PKCδ 및 cleaved PKCδ의 발현은 유의하게 증가하였으나, 다른 PKC isozyme들의 발현은 유의하게 변화하지 않았음. 그런데, 이러한 경향이 GPx-1 (+/+) 생쥐에 비하여 GPx-1 (-/-) 생쥐에서 더욱 현저하였음. 또한, Chelerythrine 혹은 rottlerin의 투여는 MA에 의해서 증가된 PKCδ 및 cleaved PKCδ의 발현을 유의하게 억제하였음. 본 연구에서 ebselen 혹은 acetylcalicylic acid maltol ester (AME)와 같은 GPx 유사 작용제의 투여가 MA로 인해 유도된 고체온증, 행동이상, 도파민성 독성, oxidative stress, 신경염증, 소교세포 활성화, PKCδ 및 cleaved PKCδ의 발현 증가 및 신경성장인자의 발현 감소를 유의하게 억제하였음. 더불어 ebselen, AME 혹은 rottlerin의 투여는 MA에 의해서 선조체에서 나타나는 mouse double minute (MDM)-2 인산화의 감소와 p53 발현의 증가를 유의하게 억제하였음. 이러한 ebselen, AME 혹은 rottlerin의 보호효과는 GPx-1 (+/+) 생쥐에서 GPx-1 (-/-) 생쥐에 비하여 더욱 현저하였음. GPx-1 (-/-) 생쥐에 GPx-1 gene-encoded adenovirus vector를 이용하여 GPx-1 유전자를 선조체 내에 주입한 결과, GPx-1 유전자의 발현이 유의하게 증가하였는데, control vector가 주입된 GPx-1 (-/-) 생쥐에 비하여 GPx-1 유전자가 주입된 GPx-1 (-/-) 생쥐에서 MA에 의한 고체온증, 행동이상, 도파민성 신경독성 및 PKCδ의 발현 증가가 유의하게 억제되었음. 또한, MA에 의한 고체온증, 행동이상, 도파민 회전율의 증가와 선조체에서의 GPx-1 발현의 감소가 PKCδ (-/-) 생쥐에서 PKCδ (+/+) 생쥐에 비하여 유의하게 억제되었음. 이상의 결과는 GPx-1 유전자가 MA에 의한 도파민성 신경독성을 억제하는 중요한 인자임과 동시에 PKCδ 유전자가 MA에 의한 신경독성의 발현과정에 관여함을 제시함. GPx-1 유사 작용제는 PKCδ 발현, oxidative stress 및 신경염증을 억제함으로써 MA에 의한 신경독성을 억제하였음

Cloning and Characterization of Valuable Genes of Chrysanthemum

Duong Huyen Trang The Graduate school of Dong-A university 2012 국내석사

국화 유래 유용 유전자 클로닝 및 기능 해석 Cloning and Characterization of Valuable Genes of Chrysanthemum 의생명과학과 Duong Huyen Trang 지 도 교 수 김 경 태 국화는 세계적으로 가장 중요한 절화와 분화식물중에 하나이다. 유전적, 분자적 기술과 함께 전통적인 육종은 꽃의 색과 크기 및 형태, 식물의 높이, 성장모양과 빛의 질에 대한 민감성을 통해 관상용 화훼작물로써의 가치 강화에 집중된다. 국화의 형질전환은 분류학상의 장벽을 넘은 유전자에 암호화된 특성의 도입을 허락함으로써 더 광범위하고 다양한 작물향상을 고려한다. Auxin response factors (ARFs)는 옥신 반응 유전자의 발현을 규제하는 전사인자이다. ARFs 집단은 ARF5와 ARF1는 배발생에, ARF7, ARF19, ARF10과 ARF16은 뿌리발달에, ARF2, ARF3, ARF6과 ARF8은 꽃발달에, 그리고 ARF1과 ARF2에 의한 노화에 관여하는 것으로 알려져 있다. 그러나 ARF18의 기능은 명확하지 않다. 그래서 ARF18의 기능을 연구하기 위해 애기장대와 국화로 애기장대 유래의 ARF18유전자를 옮겼다. 형질전환된 애기장대에서의 기관 내 세포크기는 증가했다. 그것은 AtARF18가 애기장대의 세포크기에 있어 영향을 준다는 것을 나타낸다. 형질전환된 국화에 6개의 형질전환라인을 가지고 있고 꽃에 대해 연구하였다. 우리는 ARF18 OX 8T와 ARF18 OX20T 2라인을 선택하였고 꽃잎의 길이를 측정하였다. 우리는 형질전환된 꽃이 야생형보다 꽃잎의 크기가 길다는 것을 알았다. 그러나 그것은 AtARF18이 꽃잎크기에 영향을 미친다고 말하기에는 충분하지 않다. 애기장대 유래의 FLOWERING LOCUS T (AtFT) 는 광주반응에 중요한 역할을 하며 AtFT 유전자의 돌연변이가 일어나면, 그 결과 유도적인 장일 조건에서 개화가 빨리 일어나는 것이 특징이다. 하지만 단일조건에서의 FT 유전자의 기능은 아직 알려지지 않았다. CmFT 유전자는 국화 λ phage cDNA 라이브러리로부터 CmFT 특정 프라이머를 사용하여 PCR을 수행하여 분리하였다. CmFT 유전자의 염기서열 분석 결과로 상동성을 비교한 결과, 애기장대와 국화 간의 상동성 유사관계가 72%로 나타났다. CmFT 유전자의 정확한 기능을 알고자 이 CmFT 유전자를 CaMV 35S 프로모터와 Super 프로모터를 가지는 pCAMBIA 3300에 클로닝 하였다. 구축된 CmFT 발현 시스템을 애기장대에 형질전환 시켰고 지금 그 형질전환체의 분석을 기다리고 있다. 이 분석을 토대로 CmFT 애기장대에서의 역할 규명을 한 다음, 국화로 형질전환을 할 것 이다. 주요어 : 애기장대, 국화, AtARF18, CmFT.

TOWARD A LOW ENERGY CONSUMPTION SINGLE CELL TESTING SYSTEM

DUONG DUY DUONG 가천대학교 일반대학원 2022 국내박사

The concept of microfluidic devices and its applications are well established and poses leading contributions in industries owing to great prospective in varied applications like biomedical research, clinical diagnostics, immunoassays, and many more. The inclination for miniaturized and simplify instruments for faster, cost-effective fabrication, and deployment is the primary causal objective for this thesis. Before this objective can be apprehended considerable research and development must be performed in several areas where existing microfluidic design suffer limitations, for example expensive materials and overly design lead to low level of reproducibility. When arrested this will allow the use of less expensive and more accessible method to fabricating and test a microfluidic system. The aim of the thesis is to present a few projects where design, fabrication and representation of such microfluidic devices have been performed. The final goal of my work is conceptualization of a single cell analysis system which can be easy to fabricate and operate on a minimal amount of energy. In the first chapter, I summarized the work that has been elaborately discussed in the following chapters. Chapter 2 will talk about a microfluidic device with the function of single cell encapsulation and passively sorting encapsulated cell utilizing inertia. The output encapsulated cells can be used in other applications such as molecular diagnostic to tissue engineering. In the next chapter, I introduce a system of high throughput electrical cell lysis microfluidic device. The device can be used to quickly lyse a large volume cell for the purpose of harvesting the cell’s content. In the final chapter, a microfluidic device that use the energy harvested from small temperature differences to extract cell contents was developed. This is designed with the aim of a quick and easy deployment of the system with no requirement of previous training.

Expression and functional roles of UNC13D in the progression of pancreatic cancer

Duong, Thanh Van Pusan National University 2025 국내박사

Pancreatic cancer (PC) is one of the most deadly cancers due to its late diagnosis and early metastasis, whose molecular mechanism is not fully understood. Recycling endosomal vesicles is fundamental to the migration of cancer cells, which in turn drives the metastasis of pancreatic cancer, a major contributor to cancer-related deaths. In this study, a comprehensive analysis of public resources revealed that higher expression of UNC13D was significantly associated with a poor prognosis in four independent pancreatic cancer cohorts. Besides, the expression level of UNC13D was markedly higher in the PC tissues than in the matched normal tissues. However, the role of UNC13D in PC remains unknown. Functional roles of UNC13D in the progression of PC, particularly as a key molecule promoting cancer cell migration were explored in this study. Biological studies have revealed that UNC13D plays a crucial role in the migration of pancreatic cancer cells by coupling the exocytosis of recycling endosomes with focal adhesion turnover via the regulation of FAK phosphorylation. Additionally, the formation of the RAB11-UNC13D-FAK axis in endosomes during integrin recycling was evidenced by immunoprecipitation and immunocytochemistry. Notably, co-immunoprecipitation and immunoblotting data indicated that UNC13D directly interacted with the FERM domain of FAK and regulated FAK phosphorylation in a calcium-dependent manner. Taken together, these results suggest that UNC13D, a novel prognostic factor, promotes pancreatic cancer progression by coupling integrin recycling with focal adhesion turnover via the RAB11-UNC13D-FAK axis for the migration of pancreatic cancer cells.