• Title/Summary/Keyword: Vietnam National University

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Inhibitory Components from Glycosmis stenocarpa on Pepper Mild Mottle Virus

  • Kim, Jang Hoon;Yoon, Ju-Yeon;Kwon, Sun Jung;Cho, In Sook;Nguyen, Manh Cuong;Choi, Seung-Kook;Kim, Young Ho;Choi, Gug Seoun
    • Journal of Microbiology and Biotechnology
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    • v.26 no.12
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    • pp.2138-2140
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    • 2016
  • The goal of this study was to identify a source of natural plant compounds with inhibitory activity against pepper mild mottle virus (PMMoV). We showed, using a half-leaf assay, that murrayafoline-A (1) and isomahanine (2) isolated from the aerial parts of Glycosmis stenocarpa have inhibitory activity against PMMoV through curative, inactivation, and protection effects. Using a leaf-disk assay, we confirmed that 2 inhibited virus replication in Nicotiana benthamiana. Using electron microscopy, we found that a mixture of the virus with 2 resulted in damage to the rod-shaped virus.

Determinants of Liquidity in Manufacturing Firms

  • VU, Thu Minh Thi;TRUONG, Tu Van;DINH, Dung Thuy
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.12
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    • pp.11-19
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    • 2020
  • This study examines the factors that affect firm's liquidity in manufacturing companies listed in Vietnam. Factors studied include the board size, the board independence, the firm size, the firm age, and its return. We use different metrics to measure firm's solvency status, including the cash ratio, the quick ratio, and the cash conversion cycle. Accordingly, three econometric models are built to test hypotheses proposed by researchers in order to explain the relationship between the five factors above and liquidity's measures. The study used the data set of manufacturing companies listed on the Ho Chi Minh City Stock Exchange in the period from 2015 to 2019. The final sample group comprises 139 firms with 633 observations. The results show that in manufacturing firms, while the cash ratio and the quick ratio are positively associated to the board size, the board independence, and the firm's profitability, the net operating cycle is negatively correlated to the board size, the firm size, the board independence, and the profitability. Therefore, larger firms with larger board size and more independent members can help to improve capital management efficiency.There is no evidence for the relationship between the firm age and solvency measurements, between cash conversion cycle and firm's profitability.

Competitiveness of the Clothing and Textile Industry in North Korea (북한 섬유 및 의류산업 경쟁력 분석)

  • Lee, Yu-Ri;Choi, Yun-Jung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.36 no.8
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    • pp.885-899
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    • 2012
  • This study investigates the competitiveness of the clothing and textile industry in North Korea, compare to those of China, Hong Kong, India, Indonesia, Japan, South Korea, Thailand, and Vietnam from 1993 to 2010; in addition, it explores the potential cooperation between South Korea and North Korea. First, a revealed comparative advantage (RCA) was used to investigate the competitive performance of clothing and textile industry in North Korea. The results reveal that North Korea and Viet Nam had superior comparative advantages from 1993 to 2010. Second, in order to investigate the factors that affect the competitive performance, depth interviews based on Porter's Diamond of Competitive Advantage were designed and completed by government officers and practitioners working in the clothing and textile industry field. The results show that cheap labor, the stable demand of South Korea and China for basic products, lack of supporting and related industries, and organizational power highly influence the competitive performance of clothing and textile in North Korea. This result provides insight into the potential and limitations of the clothing and textile business. In addition, this study provides a better understanding of the effects of inter-Korean economic cooperation in socialist states.

Quantitative comparison of acidic polysaccharides in the endosperm of two major varieties of rice

  • Hyun, Gyu Hwan;Lim, Dong Kyu;Kwon, Sung Won
    • Analytical Science and Technology
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    • v.30 no.4
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    • pp.205-212
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    • 2017
  • Rice endosperm, the portion that remains after milling, is the part of the rice seed that is primarily consumed as a source of nutrients. There have been many studies on polysaccharides, such as hemicellulose, cellulose, and pectins, derived from the cell walls of various plant groups. It has been reported that the acidic polysaccharide fractions, which contain water-soluble pectins that have been shown to have pharmacological effects in vivo and in vitro, have common chemical structures that include galacturonic acid polymers, rhamnose, arabinose, and galactose. However, few studies have been conducted on the acidic polysaccharides contained in the endosperm of rice. In this study, we quantitatively compared the differences in the acidic polysaccharide contents from samples from two of the main varieties of rice consumed as staple foods, japonica and indica, using a colorimetric method. Rice samples were collected from 39 different regions in Korea, China, Thailand and Vietnam. Acidic polysaccharide fractions were obtained by precipitation of the alcohol-insoluble residue (AIR) and enzyme treatment of each sample. The total amount of carbohydrates and uronic acid in each acidic polysaccharide fraction were measured using the phenol-sulfuric acid method and the carbazole-sulfuric acid method, respectively. The differences in the total polysaccharide contents in the acidic polysaccharide fractions were not statistically significant (p = 0.07), but the uronic acid contents were significantly different between the two groups (p = 0.04).

Application of Fuller's ideal curve and error function to making high performance concrete using rice husk ash

  • Hwang, Chao-Lung;Bui, Le Anh-Tuan;Chen, Chun-Tsun
    • Computers and Concrete
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    • v.10 no.6
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    • pp.631-647
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    • 2012
  • This paper focuses on the application of Fuller's ideal gradation curve to theoretically design blended ratio of all solid materials of high performance concrete (HPC), with the aid of error function, and then to study the effect of rice husk ash (RHA) on the performance of HPC. The residual RHA, generated when burning rice husk pellets at temperatures varying from 600 to $800^{\circ}C$, was collected at steam boilers in Vietnam. The properties of fresh and hardened concrete are reviewed. It is possible to obtain the RHA concrete with comparable or better properties than those of the specimen without RHA with lower cement consumption. High flowing concrete designed by the proposed method was obtained without bleeding or segregation. The application of the proposed method for HPC can save over 50% of the consumption of cement and limit the use of water. Its strength efficiency of cement in HPC is 1.4-1.9 times higher than that of the traditional method. Local standards of durability were satisfied at the age of 91 days both by concrete resistivity and ultrasonic pulse velocity.

Determinants of Middle Managers' Leadership in the Vietnamese Economic-Defense Enterprises

  • HOANG, Cuong Van;NGUYEN, Ngoc Huu;NGUYEN, Loan Quynh Thi;TRAN, Manh Dung
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.8
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    • pp.543-553
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    • 2020
  • The purpose of this study is to investigate factors affecting the leadership capacity of middle managers and then evaluate the corresponding effect on the performance of subordinates in Vietnamese economic and defense enterprises. Data for the study was collected from questionnaire survey of 15 economic and defense enterprises, preceded by in-depth interviews with respondents who are subordinates of the departments/divisions of these enterprises. The research used logistic regression estimator to address econometric issues and to improve the accuracy of the regression coefficients. Our results show that the determinants of the leadership capacity of mid-level managers in defense and economic enterprises include: (i) personal qualities and qualities of managerial officials (understanding, courage), fairness, assertiveness and compliance), and leadership behaviors of two leadership styles - (ii) a transforming leadership style (influenced by ideals, inspirations, concerns) subordinates, stimulating intellect) and (iii) transactional leadership style (rewarding, detecting and handling problems for subordinates). Based on these results, our study suggests that middle managers should possess superior knowledge, care more about subordinates, understand the strengths and weaknesses of each subordinate, always be creative, assertive and courageous people as well as have high standards of competency and morality in order to become outstanding leaders in Vietnamese economic and defense enterprises.

The Effect of Contextual Factors on Resistance to Change in Lean Transformation

  • TRAN, Duc Trong;PHAM, Huong Thu;BUI, Van Thu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.479-489
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    • 2020
  • The purpose of this paper is to uncover whether and how contextual factors (information exchange, participation, trust in management, and training), relate to resistance to change. It also explores the mediating effect of perceived impact of change on the relations between contextual factors and resistance to change. This study is conducted in several manufacturing plants in food processing industry in Vietnam, which is implementing a top-down large-scale change - Lean transformation, adopting Total Productive Maintenance (TPM) program, to be specific. The findings suggest that all four contextual factors are negatively associated with resistance to change, in which training had the strongest impact. Also, the perceived change impact partially mediates the relationships between the four contextual factors and resistance to change. The practical implications of this paper are that employees who receive adequate, timely and useful information relating to change are less likely to show opposing behaviors towards change. Fostering trust in management among employees, and employee involvement in decision-making, also have a significant influence when addressing employee resistance to change. Employees who are well-trained, well-equipped with tools and knowledge about the change, are less likely to resist as they view the benefits of changes more significant than the risks.

Predictors of Acculturation Types among Marriage Migrant Women (결혼이주여성의 문화적응유형과 영향요인)

  • Lee, Jiyeon;Chung, Grace H.;Yoo, Joan P.
    • Journal of Families and Better Life
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    • v.32 no.3
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    • pp.1-15
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    • 2014
  • This study aimed to identify predictors of acculturation types among marriage migrant women at the individual and dominant society levels. To accomplish this goal, we recruited marriage migrant women from China and Vietnam, classified their acculturation types according to their scores on acculturation attitudes, and performed multinomial logistic regression on acculturation types by entering marriage migrant women's individual and dominant society level factors as covariates based on previous research. The results showed that most of the participants were classified under integration(N=376), followed by assimilation(N=66), separation(N=60) and marginalization(N=48). Lower household income, lower sense of mastery, weaker ethnic identity and lower social support predicted assimilation as compared to integration. Less education, higher household income, weaker ethnic identity, lower family satisfaction and lower social support predicted separation as compared to integration. Finally, as compared to integration, marginalization was predicted by lower sense of mastery, lower ethnic identity and lower social support. This study expands the current scholarship on acculturation by examining acculturation as an indicator of the psychosocial adaptation of immigrants and by identifying factors that predict specific acculturation types among marriage migrant women.

Spillover Effects of FDI on Technology Innovation of Vietnamese Enterprises

  • HOANG, Duc Than;DO, Anh Duc;TRINH, Mai Van
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.655-663
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    • 2021
  • This paper aims to develop a conceptual framework for determinants of spillover effects of FDI on technology innovation of Vietnamese enterprises. The research proposes a logistic regression model for assessing how enterprises' ability to implement technological innovation is affected by the presence of FDI enterprises as well as other factors that show the change through the indirect influence of FDI such as the size of the enterprise, the type of enterprise, and the skill level of the labor force or its research and development activities. Five forms of technology innovation are considered: improving production process; product quality improvement; product expansion; expanding business activities into a new field of production; and changing business activities into a new field of production. General Statistics Office of Vietnam provided survey data to collect information from 3,166 enterprises in the manufacturing and processing industry in Hanoi, which were valid for analysis. The results show that all variables of enterprise type, size, R&D, and industry have a positive impact on the selection of one of the innovation forms. Several recommendations are further suggested to take advantage of the positive effects and minimizing the negative effects of FDI for technological innovation of Vietnamese enterprises.

Neuroprotective mechanism of corydaline in glutamate-induced neurotoxicity in HT22 cells

  • Baskar Selvaraj;Dae Won Kim;Ki-Yeon Yoo;Keunwan Park;Thi Thu Thuy Tran;Jae Wook Lee;Heesu Lee
    • International Journal of Oral Biology
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    • v.49 no.1
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    • pp.10-17
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    • 2024
  • Glutamate-mediated oxidative stress causes neuronal cell death by increasing intracellular Ca2+ uptake, reactive oxidative species (ROS) generation, mitogen-activated protein kinase (MAPK) activation, and translocation of apoptosis-inducing factor (AIF) to the nucleus. In the current study, we demonstrated that corydaline exerts potent neuroprotective effects against glutamate-induced neurotoxicity. Treatment with 5 mmol/L glutamate increased cellular Ca2+ influx, ROS generation, MAPK activation, and AIF translocation. In contrast, corydaline treatment decreased cellular Ca2+ influx and ROS generation. Western blot analysis revealed that glutamate-mediated MAPK activation was attenuated by corydaline treatment. We further demonstrated that corydaline treatment inhibited the glutamate-mediated translocation of AIF to the nucleus. We propose that corydaline is a promising lead structure for the development of safe and effective neuroprotectants.