Shear strength prediction of stud shear connection through augmented data and machine learning

Vu, Nhung 중앙대학교 대학원 2024 국내석사

Using ZINC finger protein for DNA quantification by microfluidic homogeneous electrophoretic affinity (MHEA)

Nhung, Tran Nguyen Anh Hongik University, Graduate School 2019 국내석사

Facile synthesis of SERS-active metal (Au, Ag) nanoflowers in the presence of chitosan

Nhung, Tran Thi Gachon Univ. 2012 국내박사

Role of high phosphate on vascular calcification and metabolic homeostasis

Nhung Thi Nguyen Graduate School, Yonsei University 2021 국내박사

Hyperphosphatemia has been related to a variety of health problems such as vascular calcification (VC), defective insulin secretion, and aging-related diseases. In chronic kidney disease (CKD) patients, dysfunctional excretion of inorganic phosphate (Pi) causes VC which is a severe complication contributing to high frequencies of cardiovascular morbidity and mortality. Recently, many studies have provided evidence showing that oxidative stress triggered upon high Pi condition facilitates osteogenic differentiation and calcific alterations in vascular smooth muscle cells (VSMCs). However, the molecular mechanism accountable for oxidative stress elicited by high Pi has not been clearly clarified. Previous studies indicated that mitochondrial Pi uptake was critical in defective insulin secretion under high Pi conditions. To date, the involvement of mitochondrial Pi transport has not been studied in Pi-elicited VC. In this study, I have explored the molecular mechanism of oxidative stress related with disturbance in intracellular calcium concentration ([Ca2+]i) by high Pi, which contributes to the calcification of VSMCs. Primary VSMCs isolated from rat thoracic aorta or a clonal cell line, A7r5 cells were used in this study. Incubation with high Pi stimulated extracellular signal-regulated kinase (ERK1/2) and mammalian target of rapamycin (mTOR), which are critical for VC. Increase of extracellular Pi augmented expressions of type III sodium-phosphate cotransporters, PiT-1 and -2. Notably, elevated Pi not only increased total PiT-1/2 protein level but also facilitated PiT-1/2 trafficking to the plasma membrane. Remarkably, high Pi induced plasma membrane depolarization and [Ca2+]i increase which were exclusively dependent on PiT-1/2. Verapamil, a voltage-gated Ca2+ channel (VGCC) blocker, inhibited Pi-triggered [Ca2+]i rise, ERK1/2 activation, osteogenic upregulation, oxidative stress and calcification. All of these pathogenic processes were exactly eliminated by intracellular Ca2+ chelation, extracellular Ca2+ free condition, or suppression of oxidative stress. The present study further shows that mitochondrial Pi uptake in general, and particularly via mitochondrial phosphate carrier (PiC) are highly responsible for mitochondrial oxidative stress. Under high Pi condition, the upregulation of PiC created a favorable condition for mitochondrial Pi uptake stimulating mitochondrial hyperpolarization, reactive oxygen species (ROS) generation as well as development of VC. Remarkably, application of butyl malonate (BMA), a non-selective pharmacological blocker of mitochondrial Pi uptake or Slc25a3 knockdown significantly blocks detrimental intracellular signaling and calcification caused by elevated Pi. Taken together, this study suggests that elimination of either [Ca2+]i overload or mitochondrial Pi uptake could be a potential target to prevent VC, particularly in CKD patients. Here, I also have explored the impacts of high Pi diet (HPiD) in rodent metabolism. I have discovered that HPiD reduced body weight gain and the fat mass with enhanced insulin sensitivity in mice fed with high fat diet (HFD). Assessment of adipose tissue showed that HPiD stimulated browning of white adipocytes with the activation of peroxisome proliferator-activated receptor gamma (Pparγ), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1α) and uncoupling protein 1 (Ucp1). Moreover, serum level and hepatic expression of fibroblast growth factor 21 (Fgf21) were significantly increased upon HPiD that potentially contributes to metabolic effects of this mouse model. Along with the increase of Fgf21, growth differentiation factor 15 (Gdf15) and antioxidant enzymes including nqo1, gpx3, gstm1, gstm2, nrf2, txn2, gstt3 in liver were also upregulated, suggesting that high Pi triggered oxidative stress and turned on mitochondrial stress response. All of the changes suggest that feeding mice with HPiD is beneficial for their metabolism. However, fibrotic markers such as α-smooth muscle actin (αSMA), plasminogen activator inhibitor-1 (PAI-1) and collagen content were augmented in the kidneys of mice fed HPiD demonstrating that HPiD induces renal fibrosis. All of these findings could be employed to understand the clinical complications of hyperphosphatemia, especially in patients with CKD. 고인산혈증은 혈관 석회화, 인슐린 분비 결함, 및 노화와 같은 다양한 질환과 관련 있다. 만성신장질환(Chronic kidney disease, CKD) 환자에서 무기인산염(Inorganic phosphate, Pi)의 기능장애는 심혈관질환 발생과 사망률 증가의 원인인 혈관석회화(Vascular calcification, VC)를 초래한다. 고인산혈증에 의한 산화 스트레스는 혈관 평활근세포(vascular smooth muscle cells, VSMC)의 골형성 분화와 혈관석회화를 촉진하는 것으로 보고되었으나, 고 Pi 에 의한 산화스트레스의 분자 메커니즘은 명확하게 규명되지 않은 실정이다. 이전 연구에서 고 Pi 에 의한 미토콘드리아 Pi 유입은 고Pi에 의해 매개되는인슐린 분비 손상을 유발함이 보고되었다. 하지만 현재까지 혈관 석회화를 일으키는 Pi와 미토콘드리아 Pi 조절에 대한 연관성은 규명되지 않았다. 본 연구에서는 혈관 평활근세포 석회화에 매우 중요한 고 Pi 에 의한 세포내 칼슘 농도([Ca2+]i) 변화와 관련된 산화스트레스의 분자메커니즘을 랫트 대동맥에서 분리한 1차 혈관 평활근세포와 immortalized A7R5 세포주를 이용하여 규명하고자하였다. 고 Pi 처치는 혈관 석회화에 중요한 extracellular signal-regulated kinase (ERK1/2) 와 mammalian target of rapamycin (mTOR)를 활성화하였으며, 세포 Type III Na+-의존적 Pi 수송체인 PiT-1과 2의 발현을 증가시키켰다. 특히, 고 Pi 처치는 총 PiT-1/2 단백질 발현 뿐만 아니라, 세포막에서의 PiT-1/2발현향을 증가시켰다. 특히, 고 Pi 은 세포막 탈분극과 PiT-1/2-의존적 [Ca2+]i 증가를 유발하였다. 막전압의존적 칼슘채널(Voltage-gated Ca2+ channel, VGCC) 억제제인 Verapamil은 Pi 에 의해 유발 된 [Ca2+]i 상승, ERK1/2 활성화, 골형성 , 산화스트레스 및 석회화를 억제하였다. 이러한 보호 효과들은 모두 세포내 Ca2+ chelation, 세포 외 Ca2+ 제거 또는 산화스트레스의 억제에 의해 차단되었다. 특히 미토콘드리아 인산염 운반체(PiC)를 통한 미토콘드리아 Pi 흡수가 미토콘드리아 산화스트레스 유발의 주된 원인으로, 고 Pi에 의한 PiC의 과활성화는 미토콘드리아 전위의 과분극, 활성산소(ROS) 생성과 석회화를 매개하는 주된 기전이었다. 또한, Pi-에 의한 세포내 칼슘과 석회화는 미토콘드리아 Pi 흡수 차단제인 butyl malonate(BMA) 처리 또는 PiC knock down에 의해 억제되었다. 이는 [Ca2+]I 과부화 또는 미토콘드리아 Pi 흡수 제어가 혈관 석회화, 특히 만성신장질환 치료 표적이 될 수 있음을 시사한다. 다음으로, 고Pi 식이 요법(High Pi diet, HPiD)에 의한 대사조절기전을 마우스를 이용하여 규명하고자 하였다. HPiD가 인슐린 민감성(sensitivity)을 강화하여 체중증가와 체지방을 감소시키고, 고지방식이(HFD)에 의한 인슐린저항성이 억제되었다. 지방 조직에서 HPiD는 peroxisome proliferator-activated receptor gamma (Pparγ) / peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Pgc1α) 와 uncoupling protein 1 (Ucp1)의 활성화를 통해 백색지방조직이 갈색지방으로 분화를 촉진하였으며, HPiD는 혈청과 간에서 fibroblast growth factor 21 (Fgf21) 발현 증가를 통해 대사를 개선시켰다. 또한 간에서 FGF21의 증가에 따라 미토콘드리아 스트레스 인자인 growth differentiation factor 15 (Gdf15) 과 nqo1, gpx3, gstm1, gstm2, nrf2, txn2, gstt3 등의 항산화 효소들이 증가되었다. 이는 고Pi이 산화스트레스와 미토콘드리아 스트레스를 유발함을 시사한다. 하지만, α-smooth muscle actin, plasminogen activator inhibitor-1 및 콜라겐 함량과 같은 섬유화 표지자들은 HPiD 마우스의 신장에서 증가되었으며, 이는 HPiD가 신장 섬유화를 유발함을 시사한다. 이상의 연구 결과들은 고인산혈증의 임상적인 합병증과 특히 만성신장질환 환자들의 치료전략 수립에 새로운 지견을 제공할 것입니다.

Superplasticity of VCoCrFeMnNi high-entropy alloy processed by high-pressure torsion

Nhung Thi-Cam Nguyen Pohang University of Science and Technology 2019 국내석사

Dbx1 regulates neuronal fates and identities in the developing midbrain

TRAN, HONG NHUNG 경희대학교 대학원 2020 국내석사

The mammalian brain develops under the regulation of various transcription factors. The superior and inferior colliculus, locating in the dorsal midbrain, served an important role in visual and auditory system. Dbx1 is a transcription factor involved in fate determination in various subregions of the central nervous system. However, its role in midbrain specification had been poorly investigated. In this study, we generated the conditional knock out model Cre4747;Dbx1Δ/F (Dbx1cKO) to study midbrain development. The results revealed that Dbx1 in the midbrain played a role as regulator in maintaining normal development of the tectum structures, as well as prevented apoptosis in the midbrain.

Generation of Alk1 and Tmem100 conditional knock-in mice

Vu Phuong Nhung 가천대학교 일반대학원 2012 국내석사

Activin receptor-like kinase 1 (ALK1) and Endoglin are components of the TGF-β receptor complex, mutations in either Endoglin or ALK1 genes are responsible for the human vascular dysplasia known as Hereditary Hemorrhagic Telangiectasia (HHT). As ALK1 is preferentially expressed in the arterial endothelium, we hypothesize that ALK1 plays a pivotal role in arterialization. Due to ALK1 and Endoglin are HHT causing genes, this strongly suggest the existence of a common signaling. We hypothesize that ALK1 and ENDOGLIN signaling work in collaboration. To test these hypotheses, we propose to generate a mouse strain in which Alk1 expression can be induced in a cell-type specific manner. If our first hypothesis is correct, we anticipate arterialization of venous vessel of mice in which Alk1 expression is induced in venous endothelial cells. If our second hypothesis is correct, we predict the overexpression of Alk1 may compensate the phenotype shown in Endoglin-deficient mice. Tmem100 has been identified as a potential downstream effector gene of the ALK1 signaling in HHT. We have recently shown that Tmem100 expression was significantly depressed in Alk1-deficicent lungs. We further showed that Tmem100 expression pattern is largely overlap with that of Alk1 in developing embryos. If diminished Tmem100 expression is a key mechanism of AVM formation in Alk1 mutant mice, we expect that overexpression of Tmem100 in endothelial cells may rescue phenotype shown in Alk1-deficient mice. To test the hypothesis, we propose to generate a conditional knock-in mouse strain in which TMEM100 is over-expressed in tissue-specific manner. Approaches for the above two aims are to target the ROSA26 locus with Alk1 or Tmem100 conditional knock-in vectors in mouse embryonic stem cells. I have constructed the conditional knock-in vectors for Alk1 or Tmem100 gene, that contain three SV40 polyadenylation sequences (tpA) flanked by loxP sequences. The conditional expression of Alk1 or Tmem100 is achieved by tissue-specific Cre recombinases, which recombine out the tpA, and then allow over–expression of Alk1 or Tmem100.

Facile Synthesis of SERS-Active Metal (Au, Ag) Nanoflowers in The Presence of Chitosan

Tran Thi Nhung 가천대학교 일반대학원 2012 국내석사

Metal nanoflowers with many created “hot-spots” on the surface are the most attractive substrate in supporting for Surface-Enhanced Raman scattering (SERS) in the detection of biomolecules. This paper worked on the facile method for the fabrication of metal (Au, Ag) nanoflowers using ascorbic as reducing agent and chitosan as a capping agent. Gold annoflowers (AuNFs) with controllable size, morphology and Plasma absorbance were obtained by adjusting the experimental parameters such as chitosan concentration, pH of solution, and dosage amount of ascorbic acid. In case of silver nanoflowers (AgNFs), the morphology was easily controlled by either varying the volume of AgNO3 or chitosan concentration. These metal nanoflowers were further applied as an active SERS substrate in detecting 2-chlorothiophenol (CTP). The data showed the remarkable enhancement in SERS detection which proved the high efficiency in applying metal nanoflowers as active SERS substrate. The characteristics of as-prepared samples were analyzed by UV-Vis, SEM, TEM, SAED and XRD spectroscopy.

웹서비스 기반의 OPC Alarms and Events 의 프레임워크

Tran Van Nhung 울산대학교 일반대학원 2008 국내석사

Web technologies are becoming increasingly important for the process monitoring and control. In general, Web Service has been playing an important role as a middleware for software interoperability. In this thesis, we present a framework for design and implementation of Web Service to OPC Alarms and Events (OPC AE). Our Web Service is integrated services to expose data from measurement and control devices on the plant floor by applying such technologies as OPC, XML, and links to the Internet. The design of our framework provide an open-standard for the application developers in order to implement their OPC AE specification-based system. Moreover, the security solutions are considerately discussed to choose an optimal solution for applying to our system. Furthermore, the real-time support of our system is carefully analyzed. And the performance evaluations has obviously demonstrated that our design and implementation have an acceptable performance and are feasible for high speed data exchange in distributed control systems nowadays. We have also developed a demo application based on our proposal to demonstrate its practicability

OEM 주문자 유형이 브랜드 태도 및 구매의도에 미치는 영향 : 제품유형과 관여도의 조절효과를 중심으로

Nguyen Thi Nhung 금오공과대학교 2018 국내석사

본 연구에서는 OEM(Original Equipment Manufacturing) 생산방식에 따른 주문자에 초점을 맞추어 소비자들이 어떠한 OEM 주문자 유형을 선호하는지를 연구하는 것이다. 즉, 주문자가 제조업체의 경우(NB: National Brand)와 유통업체의 경우(PB: Private Brand)에 소비자 태도를 탐색적으로 연구하였다. 또한 제품유형(편의품 vs. 선매품)과 관여도(고 vs. 저)의 조절효과도 살펴보았다. 이를 위하여 2(OEM 주문자 유형: PB OEM vs. NB OEM) * 2(제품유형: 편의품 vs. 선매품)의 집단 간 차이를 분석하기 위하여 4가지 자극물을 하였고, 통계분석도구 SPSS 21.0을 활용하여 t-test, ANOVA 등의 분석을 실시하였다. 2가지 OEM 주문자 유형은 한국시장에서 거래되는 실제 OEM 제품의 사례를 적용하였다. 설문지는 대구·경북 소재 일반인, 대학생 및 대학원생을 대상으로 직접 설문방식으로 진행되었고, 수집된 데이터 중에서 266부의 응답을 최종 실증분석에 반영하였다. 본 연구의 결과는 다음과 같이 요약할 수 있다. 첫 번째, 유통업체 OEM 브랜드보다 제조업체 OEM 브랜드에 대한 선호도가 높게 나타났다. 즉, 소비자들은 제조업체 브랜드에 대한 높은 인지도와 연상으로 인하여 제조업체 OEM 브랜드에 대한 태도가 더욱 호의적이었다. 이는 OEM 제품에 대해서 소비자가 느끼는 유통업체와 제조업체 브랜드의 후광효과가 영향을 미친 것이다. 제조업체의 경우, 브랜드 명성 및 친숙도가 제품에 대한 지각된 품질에 미치는 영향이 더욱 크기 때문에 후광효과에 의해서 제조업체의 제품품질을 더욱 높게 평가한 것이다. 두 번째, 편의품(제품유형) 및 저관여(관여도)의 경우에는 OEM 주문자 유형과 상관없이 브랜드에 대한 선호도가 유사하였다. 편의품은 제품을 구입할 때 주변에서 쉽게 고민 없이 습관적으로 구입하는 특징에 따른 것이며, 관여도가 낮을 때에도 일어나는 각성, 관심, 감정적 집착의 수준이 낮은 내면의 상태로서, 그 제품에 정보탐색과 대안평가에 적극성과 신중성을 보이지 않기 때문이다. 세 번째, OEM 주문자유형에 따른 브랜드 태도는 구매의도에 긍정적인 영향을 주었다. 본 연구의 연구결과는, 최근 기업의 환경변화에 대처하기 위한 기업 간 분업 및 전략적인 브랜드 관리에 높은 시사점을 제공한다. 즉, 선매품은 제조사의 후광효과를 활용한 적극적인 브랜드 노출 광고가 효과적이라 할 수 있다. 또한 관여도 낮은 제품의 경우에는 소비자들이 쉽게 접근이 가능하도록 유통업체 OEM 브랜드와 제조업체 OEM 브랜드 모두 원가우위의 마케팅 전략이 필요할 것이다. 관여도 높은 제품의 경우에는 제품품질에 대한 우수성 인식이 중요하기 때문에 제조업체 OEM 브랜드가 더욱 적절한 OEM 전략으로 판단되었다. In this study, we focused on OEM (Original Equipment Manufacturing) order type methods and carried out what types of OEM production methods were preferred by consumers. In other words, consumer attitudes were exploratively investigated in case of the OEM orders are the manufactures (NB: National Brand) and the private (PB: private brand). We also examined the effect of product type (convenience goods vs. shopping goods) and involvement (high vs. low). To do this, four stimuli were used to analyze the differences between groups of 2 (OEM orders type: PB OEM vs. NB OEM) * 2 (product type: convenience goods vs. shopping goods) by using SPSS21.0 included t-test, ANOVA, etc. The two OEM orders types were applied to OEM products in reality that are traded in the Korean market. The questionnaire was conducted by direct questionnaire for the general public, college students, and graduate students in Dae-gu and Gyung-buk provinces, and 266 responses were included in the final empirical analysis. The results of this study can be summarized as follows. First, the preference for manufacturer OEM brand was higher than private OEM brand. Meaning, the attitude of consumers toward the former brand was more favorable than the latter due to the high recognition and association with the brand. This has affected the halo influence of private and manufacturer brands that consumers perceive about OEM products. For manufacturers, brand reputation and familiarity have a greater impact on the perceived quality of the product; therefore, the product quality is highly evaluated by the halo effect. Second, for convenience goods (product type)-can be easily, habitually and thoughtlessly purchased-and low involvement (involvement)-which is caused by minimal efforts and considerations of consumers because of insignificant effects on their lifestyle, the favour with each brands was similar regardless of OEM orders types. Low involvement leads to the circumstance that there are less attention, no alternative assessments and no comparison of consumers to products. Third, according to OEM orders types, the consumer attitude to brands has a positive effect on purchase intention. The obtained result suggests a strong implication for corporate division of labor and strategic brand management in order to withstand with the environmental changes in the company. In other quaters, with shopping goods, brand halo effect is more effective in aggressive-brand-exposure advertisement. In the case of low-involvement products, Private brand OEM and manufacturer brand OEM will need overall cost-leadership of marketing strategies so that consumers can access easily. For high involvement products, recognition of the superiority of the product quality is important, so that the manufacturer brand OEM will need a brand strategy.