Ho Chi Minh City International University

Cytokinins (CKs) are key phytohormones that not only regulate plant growth and development but also mediate plant tolerance to drought stress. Recent advances in genome-wide association studies coupled with in planta characterization have opened new avenues to investigate the drought-responsive expression of CK metabolic and signaling genes, as well as their functions in plant adaptation to drought. Under water deficit, CK signaling has evolved as an inter-cellular communication network which is essential to crosstalk with other types of phytohormones and their regulating pathways in mediating plant stress response. In this review, we revise the current understanding of CK involvement in drought stress tolerance. Particularly, a genetic framework for CK signaling and CK crosstalk with abscisic acid (ABA) in the precise monitoring of drought responses is proposed. In addition, the potential of endogenous CK alteration in crops towards developing drought-tolerant crops is also discussed.

As part of our on-going investigation into the magnetic field properties of ultracool dwarfs, we present simultaneous radio, X-ray, and Hα observations of three M9.5-L2.5 dwarfs (BRI 0021-0214, LSR060230.4+391059, and 2MASS J052338.2−140302). We do not detect X-ray or radio emission from any of the three sources, despite previous detections of radio emission from BRI 0021 and 2M0523−14. Steady and variable Hα emission are detected from 2M0523−14 and BRI 0021, respectively, while no Hα emission is detected from LSR 0602+39. Overall, our survey of nine M8-L5 dwarfs doubles the number of ultracool dwarfs observed in X-rays, and triples the number of L dwarfs, providing in addition the deepest limits to date, log(LX /Lbol) . −5. With this larger sample we find the first clear evidence for a substantial reduction in X-ray activity, by about two orders of magnitude, from mid-M to mid-L dwarfs. We find that the decline in both X-rays and Hα roughly follows LX,Hα/Lbol ∝ 10−0.4×(SP−M6) for SP & M6. In the radio band, however, the luminosity remains relatively unchanged from M0 to L4, leading to a substantial increase in Lrad/Lbol. Our survey also provides the first comprehensive set of simultaneous radio/X-ray/Hα observations of ultracool dwarfs, and reveals a clear breakdown of the radio/X-ray correlation beyond spectral type M7, evolving smoothly from Lν,rad/LX ≈ 10−15.5 to∼ 10−11.5 Hz−1 over the narrow spectral type range M7-M9. This breakdown reflects the substantial reduction in X-ray activity beyond M7, but its physical origin remains unclear since, as evidenced by the uniform radio emission, there is no drop in the field dissipation and particle acceleration efficiency. Based on the results of our survey, we conclude that a further investigation of magnetic activity in ultracool dwarfs will benefit from a two-pronged approach: multi-rotation observations of nearby known active sources, and a snapshot survey of a large sample within ∼ 50 pc to uncover rare flaring objects.

, the most reliable SARS-CoV-2 Mpro inhibitor recently reported. The binding free energy largely arises from van der Waals interaction. We also found that Glu166 forms H-bonds to all of the inhibitors. Replacing Glu166 by an alanine residue leads to ∼2.0 kcal/mol decreases in the affinity of darunavir to SARS-CoV-2 Mpro. Our results could contribute to the development of potential drugs inhibiting SARS-CoV-2.

BACKGROUND: Vaccines are effective and reliable public health interventions against viral outbreaks and pandemics. However, hesitancy regarding the Coronavirus disease (COVID-19) vaccine is evident worldwide. Therefore, understanding vaccination-related behavior is critical in expanding the vaccine coverage to flatten the infection curve. This study explores the public perception regarding COVID-19 vaccination and identifies factors associated with vaccine hesitancy among the general adult populations in six Southeast Asian countries. METHODS: Using a snowball sampling approach, we conducted a descriptive cross-sectional study among 5260 participants in Indonesia, Malaysia, Myanmar, Philippines, Thailand, and Vietnam between February and May 2021. Binary logistic regression analysis with a backward conditional approach was applied to identify factors associated with COVID-19 vaccine hesitancy. RESULTS: Of the total, 50.6% were female, and the median age was 30 years (range: 15-83 years). The majority of the participants believed that vaccination effectively prevents and controls COVID-19 (81.2%), and 84.0% would accept COVID-19 vaccines when they become available. They agreed that health providers' advice (83.0%), vaccination convenience (75.6%), and vaccine costs (62.8%) are essential for people to decide whether to accept COVID-19 vaccines. About half (49.3%) expressed their hesitancy to receive the COVID-19 vaccines. After adjustment for other covariates, COVID-19 vaccine hesitancy was significantly associated with age, residential area, education levels, employment status, and family economic status. Participants from Indonesia, Myanmar, Thailand, and Vietnam were significantly more likely to express hesitancy in receiving COVID-19 vaccines than those from Philippines. CONCLUSIONS: In general, participants in this multi-country study showed their optimistic perception of COVID-19 vaccines' effectiveness and willingness to receive them. However, about half of them still expressed their hesitancy in getting vaccinated. The hesitation was associated with several socioeconomic factors and varied by country. Therefore, COVID-19 vaccination programs should consider these factors essential for increasing vaccine uptake in the populations.

This communication presents the design, optimization, fabrication, and characterization of an electronically steerable transmitarray (TA) with 2 bits of phase quantization per unit cell. The proposed TA operates in linear polarization at Ka-band and is composed of 14 × 14 reconfigurable unit-cells. Four p-i-n diodes are integrated on each unit-cell to control the radiated field phase distribution across the TA aperture. The prototype demonstrates experimentally pencil beam scanning over a 120° × 120° window, a maximum gain at broadside of 19.8 dBi, and a 3 dB fractional bandwidth of 16.2%.

The dissemination of antimicrobial resistance is an escalating problem and a threat to public health. Comparative metagenomics was used to investigate the occurrence of antibiotic resistant genes (ARGs) in wastewater and urban surface water environments in Singapore. Hospital and municipal wastewater (n=6) were found to have higher diversity and average abundance of ARGs (303 ARG subtypes, 197,816 x/Gb) compared to treated wastewater effluent (n=2, 58 ARG subtypes, 2,692 x/Gb) and surface water (n=5, 35 subtypes, 7,985 x/Gb). A cluster analysis showed that the taxonomic composition of wastewaters was highly similar and had a bacterial community composition enriched in gut bacteria (Bacteroides, Faecalibacterium, Bifidobacterium, Blautia, Roseburia, Ruminococcus), the Enterobacteriaceae group (Klebsiella, Aeromons, Enterobacter) and opportunistic pathogens (Prevotella, Comamonas, Neisseria). Wastewater, treated effluents and surface waters had a shared resistome of 21 ARGs encoding multidrug resistant efflux pumps or resistance to aminoglycoside, macrolide-lincosamide-streptogramins (MLS), quinolones, sulfonamide and tetracycline resistance which suggests that these genes are wide spread across different environments. Wastewater had a distinctively higher average abundance of clinically relevant, class A beta-lactamase resistant genes (i.e. blaKPC, blaCTX-M, blaSHV, blaTEM). The wastewaters from clinical isolation wards, in particular, had exceedingly high levels of blaKPC-2 genes (142,200 x/Gb), encoding for carbapenem resistance. Assembled scaffolds (16 and 30 kbp) from isolation ward wastewater samples indicated this gene was located on a Tn3-based transposon (Tn4401), a mobilization element found in Klebsiella pneumonia plasmids. In the longer scaffold, transposable elements were flanked by a toxin-antitoxin (TA) system and other metal resistant genes that likely increase the persistence, fitness and propagation of the plasmid in the bacterial host under conditions of stress. A few bacterial species (Enterobacter cloacae, K. pneumoniae, Citrobacter freundii, Pseudomonas aeruginosa) that were cultured from the isolation ward wastewaters on CHROMagar media harbored the blaKPC-2 gene. This suggests that hospital wastewaters derived from clinical specialty wards are hotspots for the spread of antimicrobial resistance. Assembled scaffolds of other mobile genetic elements such as IncQ and IncF plasmids bearing quinolone resistance genes (qnrS1, qnrS2) and the class A beta-lactamase gene (blaTEM-1) were recovered in wastewater samples which may aid the transfer of antimicrobial resistance.

This study aimed to fabricate the potential therapeutic scaffold to efficiently and safely fastening skin wound healing. A biocompatible grafting polymer-based thermal sensitive hybrid hydrogel (Chitosan-P123, CP) containing gelatin and curcumin was designed to be suitable stiffness for tissue regeneration. A detailed in the rheological study found that the encapsulated agents induced the change in the stiffness of the hydrogel from the hard to the soft. Especial, the thermally induced phase transition of CP hydrogel was governed by the participant of gelatin rather than curcumin. For example, at 25 wt% gelatin, CP hydrogel exhibited a unique gel-sol-gel transition following the function of temperature. Moreover, in vitro investigation revealed that the hybrid hydrogel provides the capacity of especially induced curcumin release with a sustainable rate as well as the excellent biocompatibility scaffold. Altogether with in vivo study, the hybrid hydrogel highlighted the advance of the dual synergistic of curcumin and gelatin in development of smart scaffold system, which promoted the efficacy in the regeneration of the structure and the barrier's function of damaged skin such as wound or skin cancer.

The purpose of the research is to identify antecedents of mobile wallet continuance intention in Vietnam. A self-administered questionnaire was distributed to collect data from a total of 276 respondents. Partial least squares structural equation modeling was employed for analyzing the data. Five mobile wallet features - mobile application quality, mobile wallet familiarity, situational normality, payment security, and feedback mechanism - are introduced as fundamental elements, which influence customer' continuance intention to use mobile wallet in Vietnam. The results indicate that mobile quality application and familiarity can significantly influence perceived ease-of-use (PEOU) and perceived usefulness (PU), but situational normality has an impact only on PEOU. PEOU and PU are positively related to satisfaction. On the other hand, payment security and feedback mechanism affect positively customer' trust. As a result, the positive effects that satisfaction and trust have on electronic wallet continuance intention are confirmed. The findings can be used to advise mobile wallet providers to improve their platform design and services to retain users. As a theoretical contribution, this study combines the Technology Acceptance Model, Unified Theory of Acceptance and Use of Technology to investigate the key determinants on continuance intention in the context of electronic wallet in Vietnam.

BACKGROUND: Mass vaccination campaigns have significantly reduced the COVID-19 burden. However, vaccine hesitancy has posed significant global concerns. The purpose of this study was to determine the characteristics that influence perceptions of COVID-19 vaccine efficacy, acceptability, hesitancy and decision making to take vaccine among general adult populations in a variety of socioeconomic and cultural contexts. METHODS: Using a snowball sampling approach, we conducted an online cross-sectional study in 20 countries across four continents from February to May 2021. RESULTS: A total of 10,477 participants were included in the analyses with a mean age of 36±14.3 years. The findings revealed the prevalence of perceptions towards COVID-19 vaccine's effectiveness (78.8%), acceptance (81.8%), hesitancy (47.2%), and drivers of vaccination decision-making (convenience [73.3%], health providers' advice [81.8%], and costs [57.0%]). The county-wise distribution included effectiveness (67.8-95.9%; 67.8% in Egypt to 95.9% in Malaysia), acceptance (64.7-96.0%; 64.7% in Australia to 96.0% in Malaysia), hesitancy (31.5-86.0%; 31.5% in Egypt to 86.0% in Vietnam), convenience (49.7-95.7%; 49.7% in Austria to 95.7% in Malaysia), advice (66.1-97.3%; 66.1% in Austria to 97.3% in Malaysia), and costs (16.0-91.3%; 16.0% in Vietnam to 91.3% in Malaysia). In multivariable regression analysis, several socio-demographic characteristics were identified as associated factors of outcome variables including, i) vaccine effectiveness: younger age, male, urban residence, higher education, and higher income; ii) acceptance: younger age, male, urban residence, higher education, married, and higher income; and iii) hesitancy: male, higher education, employed, unmarried, and lower income. Likewise, the factors associated with vaccination decision-making including i) convenience: younger age, urban residence, higher education, married, and lower income; ii) advice: younger age, urban residence, higher education, unemployed/student, married, and medium income; and iii) costs: younger age, higher education, unemployed/student, and lower income. CONCLUSIONS: Most participants believed that vaccination would effectively control and prevent COVID-19, and they would take vaccinations upon availability. Determinant factors found in this study are critical and should be considered as essential elements in developing COVID-19 vaccination campaigns to boost vaccination uptake in the populations.

Universities are increasingly utilising social media for student recruitment, the most highly used channel for prospective students. However, research on information gathering and electronic word-of-mouth (eWOM)-seeking behaviours on social media is generally absent. This paper explores the information sought by prospective students on social media, by analysing data from actual conversations on Quora, a social media question-and-answer site. Content analysis of 865 questions was conducted to examine the information regarding the factors students seek when selecting a university. The findings report information requirements on five major dimensions, namely reputation, career prospect, learning and leaching, administration and student life. This paper contributes to higher education literature by revealing the university information search factors students most commonly seek on social media, utilising a unique data source derived from actual online questions. Through understanding the eWOM-seeking behaviours of prospective students, universities can more accurately target their social media content.

Network slicing is considered to be a crucial feature of fifth generation cellular systems. By dividing the network infrastructure into multiple logical segments, network slicing can support parallel services with different requirements. While technology developments focus on slicing the core networks, there are limited studies in network slicing for radio access networks (RAN). Hence, in this letter, we study the RAN slicing and slice coordination, which is formulated as a bi-convex problem. Even though there are complicated couplings between the RAN resource allocation for each slice and the coordination of the slices that share the same resources, we design two algorithms addressing these couplings of this bi-convex problem. Simulation results validate the efficacy of our proposed algorithms.

Water pollution caused by antibiotics is perceived with deep concern nowadays. It can be hardly removed by traditional wastewater treatment plants. Fluoroquinolones (FQs), a kind of antibiotics, have been considered emerging contaminants that have brought severe threats to biota and human health. The role of removal technique becomes more important with the increase in the concentration of these contaminants in water streams. Therefore, research into the use of advanced approaches for the removal of FQs is a challenge to the scientific community. Although advanced oxidation processes (AOPs) have been studied enormously, the reaction mechanisms and conditions as well as parameters affecting the removal process have not been deeply investigated. For example, pH, materials dosage, and contaminant concentration have a significant influence on the removal process of FQs. This review systematically summarizes and discusses the effects, fate, mechanisms, and influencing parameters in the degradation process of FQs of the most recent innovative methods including adsorption, electrochemical oxidation, Peroxymonosulfate (PMS) activation by transitional metal-based composites, photocatalysis, and biological processes. Thus, this review also addresses the combination potentials of AOPs for the degradation of antibiotics in water matrices.

Abstract This work examines the impact of greenwash on green brand equity and analyses the mediation effects of green brand image, green satisfaction and green trust as well as the moderating effect of information and knowledge based on the legitimacy theory and signalling theory. This study adopts a questionnaire‐based survey design to gather data from 445 respondents using a cluster random sampling technique. Data collection focuses on Vietnamese consumers who had purchased electronic products in Ho Chi Minh City, Vietnam. The findings show that although greenwash is not significantly related to green brand equity possibly due to the halo effect, greenwash is adversely related to green brand image, green satisfaction and green trust, which would positively influence green brand equity. In other words, green brand image, green satisfaction and green trust play a full mediation role in the relationship between greenwash and green brand equity. In addition, information and knowledge actually moderate the relationship between greenwash and green brand equity, and it strengthens the adverse relationship between greenwash and green brand equity. This research is the first to combine green brand image, green satisfaction and green trust as mediators to shed light on the understanding of different impact mechanisms in the greenwash–green brand equity relationship. Furthermore, this research is also the first to study information and knowledge as a moderator in the greenwash–green brand equity relationship. This provides a better insight into the process and context by which greenwash affects green brand equity. Taken together, the findings of this study extend and advance the understanding regarding the different mechanisms and the dynamics in which green brand image, green satisfaction, green trust as mediators and information and knowledge as a moderator can play in the emerging market context of consumers of electronic products in Vietnam. The findings enrich the growing body of green marketing literature and contribute significantly towards a unified theory of brand equity.

In this letter, a reconfigurable unit-cell for transmitarray antenna working at X-band is presented. It is designed to provide 1-bit phase quantization using p-i-n diodes. The unit-cell is based on multilayer frequency selective surfaces with the use of two substrates and a combination of a C-patch and a ring slot loaded by a rectangular gap. It is optimized using full-wave electromagnetic simulation and verified by using waveguide simulator. The experimental results show that the unit-cell provides two values of the transmission phase with a step of 180° at 11.5 GHz. Furthermore, the unit-cell has a low thickness of 0.19λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , and is low-cost and easy to fabricate.

Abstract This research proposes a framework to explore green consumption behavior from the perspective of the anxiety of death and individual social responsibility. Research data are collected from a sample of 280 consumers in Taipei, Taiwan. The findings reveal that consumers' anxiety of death affects consumers' green purchase attitude and then ultimately green purchase intention through the mediating variables of environmental concern and pro‐environmental behavior. On a similar line, individual social responsibility is found to act as a precursor in increasing consumer's concern for the environment and, eventually, green purchase attitude and intention. Mastery is found to invigorate the effect of death anxiety on green concern and pro‐environmental behavior, while it enervates the relationship between individual social responsibility and environmental concern.

The development of improved methods for the synthesis of monodisperse gold nanoparticles (Au NPs) is of high priority because they can be used as substrates for surface-enhanced Raman scattering (SERS) applications relating to biological lipids.

In the new global economy, environmentally friendly policies have become a central issue for firms. The increasing attention given to the benefits of those policies has prompted research on the development of environmental management systems that encourage employees to engage in environmental activities. However, there is limited evidence concerning the relationship between employee motivation and employees’ in-role green performance, in addition to the potential impact of culture and organizational citizenship behavior for the environment. Through a quantitative study of 301 managerial and non-managerial employees working in three- to five-star hotels, this study makes a major contribution by demonstrating that practices aimed at motivating hotel employees (e.g. green reward and performance management) are significantly linked with employees’ in-role green performance and organizational citizenship behavior for the environment. The findings also indicate that the influence of green rewards on employees’ in-role green performance and organizational citizenship behaviors for the environment is stronger when hotels are managed by Western corporations. Conversely, the study showed that the effect of green performance management on these two dependent variables is not moderated by culture. This article supports efforts to widen national cultural perspectives in the development and application of green human resource management.

Learning management system (LMS) is considered as an important means of knowledge acquisition and learning management in the digital era. As users could be seen as the key stakeholders who impact the system’s survival, their attitudes toward system are put in high consideration. The purpose of this study is to explore the factors influencing learner’s satisfaction towards learning management system, specially Blackboard and Edusoft. Blackboard and Edusoft are the two mandatory systems that all students in International University – Vietnam National University HCMC have been using during their college. A quantitative survey is applied to current students at International University to test the influence of 4 factors: Announcement system, Instruction information, Interaction, Technology quality on Learning management system usefulness and the impact of learning management system usefulness on their satisfaction. The findings suggest the significant impact of 5 mentioned factors in learners’ satisfaction including direct and indirect relations. This study also tests the relationship between the interaction provided by learning management tool and students’ satisfaction. For students’ side, they have a chance to raise their voices by ranking the level of which factors make them concern relating to the learning management tools that they have to use day by bay during college. For university’s side, this research contributes to provide information relating to students’ perception which could help the improvement for learning management system afterward.

In recent years, Alzheimer's disease (AD) diagnosis using neuroimaging and deep learning has drawn great research attention. However, due to the scarcity of training neuroimaging data, many deep learning models have suffered from severe overfitting. In this study, we propose an ensemble learning framework that combines deep learning and machine learning. The deep learning model was based on a 3D-ResNet to exploit 3D structural features of neuroimaging data. Meanwhile, Extreme Gradient Boosting (XGBoost) machine learning was applied on a voxel-wise basis to draw the most significant voxel groups out of the image. The 3D-ResNet and XGBoost predictions were combined with patient demographics and cognitive test scores (Mini-Mental State Examination (MMSE) and Clinical Dementia Rating (CDR)) to give a final diagnosis prediction. Our proposed method was trained and validated on brain MRI brain images of the Alzheimer's Disease Neuroimaging Initiative (ADNI) dataset. During the training phase, multiple data augmentation methods were employed to tackle overfitting. Our test set contained only baseline scans, i.e., the first visit scans since we aimed to investigate the ability of our approach in detecting AD during the first visit of AD patients. Our 5-fold cross-validation implementation achieved an average AUC of 100% during training and 96% during testing. Using the same computer, our method was much faster in scoring a prediction, approximately 10 min, than feature extraction-based machine learning methods, which often take many hours to score a prediction. To make the prediction explainable, we visualized the brain MRI image regions that primarily affected the 3D-ResNet model's prediction via heatmap. Lastly, we observed that proper generation of test sets was critical to avoiding the data leakage issue and ensuring the validity of results.

Bone cement is used as a mortar for securing bone implants, as bone void fillers or as spacers in orthopaedic surgery. Antibiotic-loaded bone cements (ALBCs) have been used to prevent and treat prosthetic joint infections by providing a high antibiotic concentration around the implanted prosthesis. High antibiotic concentrations are, on the other hand, often associated with tissue toxicity. Controlling antibiotic release from ALBCS is key to achieving effective infection control and promoting prosthesis integration with the surrounding bone tissue. However, current ALBCs still need significant improvement in regulating antibiotic release. In this review, we first provide a brief introduction to prosthetic joint infections, and the background concepts of therapeutic efficacy and toxicity in antibiotics. We then review the current state of ALBCs and their release characteristics before focusing on the research and development in controlling the antibiotic release and osteo-conductivity/inductivity. We then conclude by a discussion on the need for better in vitro experiment designs such that the release results can be extrapolated to predict better the local antibiotic concentrations in vivo.