GLOBAL ATTRACTOR FOR A SEMILINEAR PSEUDOPARABOLIC EQUATION WITH INFINITE DELAY

Thanh, Dang Thi Phuong Korean Mathematical Society 2017 대한수학회논문집 Vol.32 No.3

In this paper we consider a semilinear pseudoparabolic equation with polynomial nonlinearity and infinite delay. We first prove the existence and uniqueness of weak solutions by using the Galerkin method. Then, we prove the existence of a compact global attractor for the continuous semigroup associated to the equation. The existence and exponential stability of weak stationary solutions are also investigated.

Antioxidant Activities of Vietnamese Medicinal Plants

Phuong Thien Thuong,나민균,Nguyen Hai Dang,Tran Manh Hung,Pham Thanh Ky,Tran Van Thanh,Nguyen Hai Nam,Nguyen Duy Thuan,석대은,배기환 한국생약학회 2006 Natural Product Sciences Vol.12 No.1

hundred and twenty six Vietnamese traditional herbals belonging to 59 families were screened forof seven plants, including Euphorbia thymifolia (leaf), Gnetum montanum (stem), Heterosmilax erythrantha(root), Morus alba (leaf), Syzygium formosum (leaf), Jussiaea repens (aerial parts), and Camellia sinensis (leaf),exhibited significant antioxidant activities. All of these herbs showed remarkable free radical scavenging activitieswith IC50 values of 11.0, 14.5, 17.0, 13.6, 10.8, 7.7, and 8.5g/ml, respectively, and significant inhibitory effectsconcentration of 50g/ml.KeywordsVietnamese medicinal plants, antioxidant activity, free radical scavenging, lipid peroxidation

The Impact of Consumer Ethnocentrism on Purchase Intention: An Empirical Study from Vietnam

Thanh Ngoc Dan NGUYEN,Phuong Nhu DANG,Phu Hoang TRAN,Trang Thi Thuy NGUYEN 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.2

Ethnocentrism in users plays an important role in predicting user behavior when deciding between imported and domestic goods. The purpose of this study is to look into the influence of ethnocentrism in customer behavior on brand image, perceived value, perceived quality, brand trust, and brand buy intention. Vietnamese customers prefer homegrown brands. The moderate role of consumer ethnocentrism in the conceptual framework emphasizes the country origin of the product is the most important factor. It also demonstrates how the intention of Vietnamese consumers to buy domestic brands is substantially influenced. To test the hypothesis, this article used a quantitative technique utilizing PLS-SEM software. With 917 samples, the study used the quota sampling approach to collect data from students at 10 universities in Ho Chi Minh City. The data suggest that all players have a positive association and that consumer ethnocentrism has a moderate impact in the Vietnamese brand context. Following that, suggestions are made to help Vietnamese firms create and retain their brands in the face of severe competition from global brands in the domestic market. To increase consumer intent in purchasing behavior, the Vietnamese local company needs to establish a strong brand.

HER2 Status and Its Heterogeneity in Gastric Carcinoma of Vietnamese Patient

Dang Anh Thu Phan,Vu Thien Nguyen,Thi Ngoc Ha Hua,Quoc Dat Ngo,Thi Phuong Thao Doan,Sao Trung Nguyen,Anh Tu Thai,Van Thanh Nguyen 대한병리학회 2017 Journal of Pathology and Translational Medicine Vol.51 No.4

Background: Human epidermal growth factor receptor 2 (HER2) is related to the pathogenesis and poor outcome of numerous types of carcinomas, including gastric carcinoma. Gastric cancer patients with HER2 positivity have become potential candidates for targeted therapy with trastuzumab. Methods: We investigated 208 gastric cancer specimens using immunohistochemistry (IHC), fluorescence in situ hybridization and dual in situ hybridization (ISH). We also investigated the concordance between IHC and ISH. The correlation between HER2 status and various clinicopathological findings was also investigated. Results: In total, 15.9% (33/208) and 24.5% (51/208) of gastric cancers showed HER2 gene amplification and protein overexpression, respectively. A high level of concordance between ISH and IHC analyses (91.3%, κ = 0.76) was found. A significant correlation between HER2 status and intestinal-type (p < .05) and differentiated carcinomas (p < .05) was also noted. The HER2 heterogeneity was high in gastric cancers; we found 68.8% phenotypic heterogeneity and 57.6% genotypic heterogeneity. Heterogeneity in HER2 protein expression and gene amplification showed a close association with diffuse histologic type and IHC 2+. Conclusions: HER2 protein overexpression and gene amplification were detected in 24.5% and 15.9% of gastric cancer specimens, respectively. Intestinal-type showed a higher level of HER2 protein overexpression and gene amplification than diffuse type. HER2 status also showed a significant relationship with well- and moderately-differentiated carcinomas. The ratio of phenotypic and genotypic heterogeneity of HER2 was high in gastric carcinomas and was associated with HER2 IHC 2+ and diffuse histologic type.

A dense, pinholes-free pure cubic phase CsPbBr3 nanocrystals film for high-performance photodetector

Thanh-Tung Duong,Phuong-Nam Tran,Tuan-Pham Van,Duy-Hung Nguyen,Van-Dang Tran 대한금속·재료학회 2024 ELECTRONIC MATERIALS LETTERS Vol.20 No.2

This study demonstrates a simple centrifugal coating method to prepare high-quality pure cubic phase CsPbBr 3 nanocrystalfi lm. The resultant perovskite layers possess a uniform and dense 500 nm-thick, with a bandgap of 2.38 eV, a low trap-statedensity of 6.9 × 10 − 15 cm − 3 , and carrier mobility of approximately 19.8 cm 2 V − 1 s − 1 . Furthermore, CsPbBr 3 NCs-basedself-powered photodetectors with high charge carriers’ charge transfer are fabricated. The device shows a low dark currentdensity of 1.93 × 10 − 7 A/cm 2 at room temperature. Such photodetectors show the highest responsivity of 3.0 AW − 1 ,specifi c detectivity of 1.2 × 10 13 Jones, and external quantum effi ciency (EQE) of 920% at zero bias voltage. The proposedmethod shows signifi cant promise for use in the lab fabrication of optoelectronic devices based on thin fi lms of nanocrystalperovskite materials.

An Empirical Study of Commodity Market Patterns in Ethnic Minorities and Mountainous Areas: Evidence from Vietnam

Trinh Thi Thanh THUY,Nguyen Thi BINH,Trinh Thi Thu HUONG,Nguyen Thu THUY,Dang Thanh PHUONG,Tran Thi Bao KHANH,Nguyen Thi YEN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.11

The development of the ethnic minorities and mountainous areas (EMMA) is currently receiving the attention of countries around the world. This is demonstrated through a large number of studies, in many respects, in many different countries. The objective of the study is to find out the current situation of the commodity market in the ethnic minorities and mountainous areas (EMMA) of Vietnam. In particular, the authors will study whether there is a link between the ability to access governmental policies and the characteristics of this commodity market. To achieve the goal, the authors employed the secondary data collection method to gather the relevant information on government policies for EMMA and conducted an interview of seventy (70) enterprises in the Northern midlands and mountainous regions and the Central Coast to clarify the characteristics of commodity market. By Levene’s test, the results showed that the accessibility to governmental policies has a certain influence on the development of the commodity market patterns in the EMMA in terms of diversification of distribution forms and sales method of the business. These findings brought some basic solutions to further enhance the role of the government in developing commodity markets in the EMMA of Vietnam.

Energy-Efficient Optimization of Forging Process Considering the Manufacturing History

박홍석,Trung-Thanh Nguyen,Xuan-Phuong Dang 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.3 No.2

Increasing the energy efficiency of manufacturing processes is one of the many ways to reduce manufacturing cost and to resolve environmental issues. This paper systematically investigates the manufacturing process of an automotive crankshaft via a numerical simulation approach towards energy savings. The aim of this work is to propose potential solutions for improving the energy efficiency of the forging process chain in which energetically relevant parameters are optimized variables. The process chain is holistically optimized because the manufacturing history among the different processing steps is considered. We developed a discrete-event simulation based method to facilitate the holistic optimization of the forging process chain with regards to energy efficiency. To elucidate the weaknesses of the current process chain, manufacturing data were examined. Subsequently, a discrete-event simulation (DES) model was used in conjunction with design of experiments (DOE) in order to determine significant parameters as well as optimization scenarios. Finally, energy consumption optimizations were realized based on a consideration of the parameter adjustments. The research results show that the energy efficiency of the forging process chain could be improved by approximately 10% compared to the current state. Therefore, this work contributes to make the manufacturing crankshaft become greener and more efficient.

Multi-Objective Optimization of Turning Process of Hardened Material for Energy Efficiency

박홍석,Trung Thanh Nguyen,Xuan-Phuong Dang 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.12

Improving the energy efficiency of machining processes is one way to reduce manufacturing costs in an effort to resolve environmental issues. The objective of this work is to optimize the machining parameters of the turning process for hardened AISI 4140 steel to reduce the consumed cutting energy and improve energy efficiency. The machining parameters evaluated include cutting speed, feed rate, nose radius, edge radius, rake angle, and relief angle. Firstly, numerical simulations were applied in conjunction with the Box- Behnken design (BBD) experimental method and response surface methodology (RSM) to render the relationships of the machining parameters with the specific required cutting energy as well as energy efficiency. Subsequently, a non-dominated sorting genetic algorithm-II (NSGA-II) was used to solve multi-objective optimization problems and search for Pareto optimal solutions. Finally, the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was adopted to determine the best solution compromised from the Pareto set. The results show that the specific required cutting energy decreased by approximately 16%, and the energy efficiency could be improved by about 11% compared to the non-optimized system. Therefore, this research is intended to contribute toward making machining processes of hardened steels more green and efficient.

Critical Factors of Subcontractor Evaluation and Selection: A Case Study in Vietnam

VO, Khoa Dang,PHAM, Cuong Phu,PHAN, Phuong Thanh,VU, Ngoc Bich,DUONG, My Tien Ha,LE, Loan Phuc,NGUYEN, Quyen Le Hoang Thuy To Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.3

A contractor or a main contractor is a company with full capacity to construct all project's works for the owner. A subcontractor is an organization that works with the main contractor to execute and complete work packages for the project. Selecting an effective subcontractor will help the efficiency and success of any projects in the construction industry. Therefore, this study identified subcontractor evaluation factors in Vietnam by collecting questionnaire survey data from engineers and staffs in the construction industry project environment. An exploratory factor analysis (EFA) was then performed to identify the critical factors when evaluating and selecting the subcontractor in construction projects. Moreover, when considering the impact level in terms of the average value, the research results showed that the most critical concern was the subcontractor's reputation. Furthermore, the top five factors affecting the sub-contractor evaluation and selection are (i) reputation, (ii) price, (iii) construction techniques, (iv) ability to implement projects according to commitments, and (v) subcontractor competence (the team of workers, technician staff, engineers with full capacity according to regulations). These research results provide an overall perspective that will help main contractors develop suitable subcontractors' evaluation and selection factors in their projects in the construction industry.

Design, synthesis and evaluation of novel <i>N</i>-hydroxybenzamides/<i>N</i>-hydroxypropenamides incorporating quinazolin-4(3<i>H</i>)-ones as histone deacetylase inhibitors and antitumor agents

Hieu, Doan Thanh,Anh, Duong Tien,Tuan, Nguyen Minh,Hai, Pham-The,Huong, Le-Thi-Thu,Kim, Jisung,Kang, Jong Soon,Vu, Tran Khac,Dung, Phan Thi Phuong,Han, Sang-Bae,Nam, Nguyen-Hai,Hoa, Nguyen-Dang Elsevier 2018 Bioorganic chemistry Vol.76 No.-

<P><B>Abstract</B></P> <P>In our search for novel small molecules targeting histone deacetylases, we have designed and synthesized several series of novel <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides incorporating quinazolin-4(3<I>H</I>)-ones (<B>4a-h</B>, <B>8a-d, 10a-d)</B>. Biological evaluation showed that these hydroxamic acids were generally cytotoxic against three human cancer cell lines (SW620, colon; <I>PC</I>-3, prostate; NCI-H23, lung cancer). It was found that the <I>N</I>-hydroxypropenamides (<B>10a-d)</B> were the most potent, both in term of HDAC inhibition and cytotoxicity. Several compounds, e.g. <B>4e</B>, <B>8b-c</B>, and <B>10a-c</B>, displayed up to 4-fold more potent than SAHA (suberoylanilide hydroxamic acid, vorinostat) in term of cytotoxicity. These compounds also comparably inhibited HDACs with IC<SUB>50</SUB> values in sub-micromolar range. Docking experiments on HDAC2 isozyme revealed some important features contributing to the inhibitory activity of synthesized compounds, especially for propenamide analogues. Importantly, the free binding energy computed was found to have high quantitative correlation (<I>R</I> <SUP>2</SUP> ∼ 95%) with experimental results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel quinazolin-4(3H)-one-based <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides were synthesized. </LI> <LI> The <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides exhibited potent HDAC inhibition. </LI> <LI> The <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides exhibited good cytotoxicity. </LI> <LI> Docking studies and ADMET estimation were carried out. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Two series of novel, simple <I>N</I>-hydroxybenzamides/<I>N</I>-hydroxypropenamides incorporating quinolin-4(3H)-one (<B>4a-h</B>, <B>8a-d, 10a-d</B>) were designed and synthesized. Biological evaluation showed that these benzamides/propenamides potently inhibited HDAC with IC<SUB>50</SUB> values in sub-micromolar range. A number of compounds also exhibited cytotoxicity up to 4-fold more potent than SAHA, a positive control.</P> <P>[DISPLAY OMISSION]</P>