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Electroactive poly(1,8-diaminonaphthalene) is known to have a high affinity for metal ions thanks to amine and imine groups in the polymer chain. However, electrochemical sensors based on pristine P(1,8-DAN) have a major drawback concerning its poor electrical conductivity. To solve this problem, recently P(1,8-DAN) has been modified with some advanced nanomaterials such as carbonaceous materials or different metallic elements. In this research, we reported the synthesis and electrochemical characterization of a poly(1,8-diaminonaphthalene)/graphene composite film capable of adsorbing Cu2+ ions towards the application of nitrite sensing. P(1,8-DAN) was directly electropolymerized on graphene-coated glassy carbon electrode by a potential cycling between –0.15 and +0.95 V (vs. SCE) at a scan rate of 0.05 V/s, in aqueous solution containing 1.0 M HClO4 and 1.0 mM monomer 1,8-DAN,. The adsorption of Cu2+ ions onto the P(1,8-DAN) thin film was caried out in 0.1 M Cu(NO3)2 solution at 80 oC, followed by electrochemically redution to metal Cu0 by applying -0.4 V. The obtained copper decorating poly(1,8-diaminonaphthalene)/graphene (Gr/P(1,8-DAN)-Cu) electrodes acted as a catalyst in the enhancement of electrochemical signal for the determination of nitrite. The linear voltammetric response to the nitrite concentration was observed by a square wave voltammetric technique in the range of 0.69 to 1.12 mM with a detection limit of 0.13 mM. The results open up the path for designing other nitrite sensing based on our novel approach.

Academic mobility is a popular phenomenon at universities, particularly for promoting knowledge exchange, attracts the attention scientific community in recent years, especially in the context of integration and The Fourth Industrial Revolution (FIR). Indeed, FIR is place convergency many dimensions that make mobility flows at universities more advantageous with unlimited connection and interactions, including virtual space and digital tools for mobility. The paper aims at exploring the key determinants of mobility management in higher education to respond to the impacts of FIR. The conceptual model of this study emphasizes mobility management of high-quality human resources following their contribution process: attraction/recruitment, contribution onsite, and return. The model also shows that both individuals and universities have common and unique interests in enhancing mobility flows while creating knowledge transfer regions. It is important to combine these benefits to create active mobility flows. By analyzing some typical mobility flows in a Vietnam national university Hanoi case study, we emphasized that the current philosophy of Vietnamese universities is mostly to focus on solving the lost mobility flows (brain drain) instead of going hand-in-hand with managing the value of high-quality human resource mobility and connecting networks to make to promote knowledge exchange. Thus, it requires Vietnamese universities should change for adapt to FIR’s impacts with academic mobility and manage mobility of human resources follow all their contribution process. This study explores these topics for their impact on FIR to manage mobility flows of high-quality human resources using assessment data which collected snowball methods. Finally, the paper proposes the policy framework supporting mobility management and priority solutions for promoting the knowledge interactions zones and developing smart platforms for university governance and human resource management adapting with the context of the FIR.

Objectives Mobile colistin resistance (mcr) genes are widely distributed around the world. To date, ten major variants of mcr genes are known (mcr-1 to mcr-10). However, only a few instances of Enterobacterales isolates harbouring mcr genes other than mcr-1 have been reported in Vietnam. The aim of this study was to investigate mcr-harbouring antimicrobial-resistant Enterobacterales isolates in Vietnam. Methods Two mcr-9-harbouring Enterobacter hormaechei clinical isolates (NIHE14-1904 and MH17-539M) were obtained from medical institutions in Hanoi, Vietnam, in 2014 and 2017, respectively. Their genomes and plasmid sequences were analysed by short-read and long-read sequencing. Subsequently, comparative sequence analysis of their mcr-9-carrying plasmids was performed. Results Strains NIHE14-1904 and MH17-539M belonged to sequence types ST916 and ST66, respectively, according to the Enterobacter cloacae multilocus sequence typing (MLST) scheme. NIHE14-1904 and MH17-539M harboured the mcr-9 gene on similar IncHI2 plasmids, namely pNIHE14-1904-mcr9 (373.1 kb) and pMH17-539M-mcr9 (289.3 kb), respectively. These plasmids were also highly identical to widespread IncHI2 plasmids that are often associated with mcr genes. Conclusion For the first time, mcr-9-harbouring Enterobacterales isolates were detected in Vietnam, which carried mcr-9 on IncHI2 plasmids. The prevalence of such plasmids needs to be monitored in the future owing to their high dissemination.

In-Situ composite materials of graphene (Gr) and ZnO microspindle with different Gr contents (1, 2 and 5 wt.%) were prepared via a facile one-step hydrothermal route with the assistance of hexamethylenetetramine. Graphene does not affect the hexagonal wurtzite crystal structure of composite materials but strongly affects the morphological, structural, optical and photocatalytic properties of composite materials. In detail, Gr causes a decrease in both the dimensions of ZnO microspindle and photoluminescence efficiency. The average crystalline size and microstrain first increase from 28.9 nm and 0.00394 to 49.5 nm and 0.00524 when Gr content increases from 0 to 1 wt.%, respectively; then decrease to 39.6 nm and 0.00404 when Gr content increase from 1 to 5 wt.%, respectively. Both pristine and composite materials show high photocatalytic activity with high methylene blue degradation efficiency?more than 90%-just after 40 min under UV irradiation. Composite material having a Gr content of 5 wt.% shows the highest degradation efficiency of 96.5% which confirms the role of Gr in enhancing the photocatalytic activity of ZnO.

Environmental disruptions, such as extreme weather events or poisoning of natural resources, are increasing in frequency and intensity. These critical global problems demand market- and policy-based solutions. Adopting a Transformative Consumer Research perspective, this article examines the effects of environmental disruptions on the livelihoods of a very vulnerable group: nature-dependent prosumers. Nature-dependent prosumers often live in subsistence markets, but the impact of environmental disruptions on their lives can have repercussions throughout local and global systems. This article thus offers practitioners and researchers a framework, the “cross-scale intersectionality matrix” (CSIM), to better understand the differing impacts of environmental disruptions and envisage effective solutions. The CSIM reveals how environmental disruptions affect marketing systems’ exchanges of production and consumption (1) across multiple spatiotemporal scales, resulting in cross-scale impacts (per ecosystems theory) and (2) in diverse ways for groups/individuals experiencing intersectional power asymmetries such as geopolitical/economic power, classism/ableism, and sexism (per intersectionality theory). Building on insights from the CSIM framework, the authors propose improvements to research as well as policy and market-based solutions intended to enhance the well-being of nature-dependent prosumers.

In the context of an emerging country, sustainable consumption becomes increasingly important in the pursuit of sustainable development while empirical research on this topic is generally limited. This study aims to examine the influence of actual self-image congruence on intention to purchase green products by integrating self-image congruence theory with the theory of planned behavior (TPB). Data was collected via an online survey of 539 Vietnamese consumers. The results of data analysis using structural equation modeling (SEM) showed that actual self-image congruence had a direct positive effect on consumer intention to purchase green products. Additionally, the findings showed the indirect effect of actual self-image congruence on purchase intention via attitude, subjective norm and perceived behavioral control. This research is expected to make both theoretical and practical implications.

Vietnam is a transition economy in the Southeast Asia and corporate governance in this country has been newly established after transition process in 1986. Similar to many other developing and emerging economies, Vietnam has weak external governance mechanisms, thus independent director becomes a critical element in corporate governance system as an internal governance mechanism. Further, Vietnam is also a transition economy which has a highly concentrated ownership structure with the dominance of the State as the largest controlling shareholder which may complicate the work of independent directors. Therefore, it is unclear how independent directors contributes to corporate governance and firm performance in a transition economy as Vietnam. Vietnam only releases a new Corporate Governance Code in 2012 which for the first time introduces the notion of independent directors in corporate governance with the requirement that listed companies need to maintain a certain level of independent directors on the board. There is lack of research to examine the function of independent directors in corporate governance in this country. Taking into account the importance as well as the recent adoption of independent director in corporate governance in Vietnam – a transition economy, the thesis examines this type of director from three aspects in three research papers. The first paper (chapter 2) examines the relationship between independent directors and firm performance using available archival data. Due to the nature of transition process, independent directors have been recently adopted in corporate governance system in Vietnam, thus contribution of independent directors to improving firm performance is still unclear. After using several methods to control for endogeneity - a common issue for research on corporate governance, we found that the relationship between independent directors and firm performance is negative. The findings also revealed that the negative relationship between independent directors and firm performance can be due to the dominance of firms with concentrated ownership structure. In addition, the negative relationship is even worse in firms where the State is a controlling shareholder than in firms with private controlling shareholders. Then, in the second paper (chapter 3), the thesis uses surveys to further investigate the perceptions of independent directors in listed companies in Vietnam on the roles, responsibilities and challenges for them when participating on the board of directors. The main purpose of this paper is to understand how independent directors recognize their roles in corporate governance in the absence of guidelines from corporate governance codes released in 2012 in Vietnam. The findings suggested that independent directors have preference on advisory role than monitoring role which is not suggested by prior literature. In addition, they also pointed out the challenges faced in the board including information asymmetries and influence of controlling shareholders. Finally, the third paper (chapter 4) investigated if there is any cultural difference between the north and the south of Vietnam and if this intra-cultural difference is associated with difference in creating accountability of independent directors. The results confirmed the persistence of intra-cultural difference in Vietnam between two regions in which independent directors in the south are more likely to be individualists whereas independent directors in the north are more likely to be collectivists. Additionally, independent directors in the south demonstrated a lower level of risk averse while independent directors in the north showed a higher level of risk averse. With regard to creating accountability of independent directors, the results demonstrated that independent directors in the south are more likely to be at higher level of creating accountability than directors in the north. Overall, the thesis points out some issues relating to independent directors in Vietnam and provide implications to policymakers for a further corporate governance reform relating to independent directors as well as to companies when establishing and maintaining their corporate governance systems.

g-C3N4@WO3.H2O nanoplate composite adsorbents were prepared in a simple acid precipitation method at room temperature. The g-C3N4@WO3.H2O nanoplate composite adsorbents were characterized by X-ray powder diffraction, micro-Raman spectroscopy, Fourier transform infrared spectra, scanning electron microscopy and UV-vis diffuse reflectance spectroscopy. The results show that the orthorhombic-phase WO3.H2O nanoplates with dimensions of [Formula: see text][Formula: see text]nm3 were successfully composited with g-C3N4. The methylene blue dye generation activity of these adsorbents was evaluated. The kinetics and absorption model of g-C3N4@WO3.H2O nanoplate composite adsorbents were further studied.