Vietnam Journal of Science, Technology and Engineering - C
Tạp chí của Bộ Khoa học và Công nghệ
Proposing fuel consumption limits for new vehicles to support Vietnam’s Nationally Determined Contribution
Vietnam’s Nationally Determined Contribution (NDC) sets a target of reducing total greenhouse gas emissions in the transportation sector by 34.33%, equivalent to approximately 15.66 million tonnes of CO₂, by 2030. This study was conducted to forecast the potential for achieving that target through the application of a fuel consumption limit for cars with fewer than nine seats and for motorbikes in Vietnam. The results show that the number of new cars increased rapidly from 159,289 vehicles in 2016 to 347,287 vehicles in 2022. Similarly, the number of new motorbikes increased from 2,917,086 units in 2020 to 3,202,554 units in 2022. The average fuel consumption of vehicles with fewer than nine seats and an average engine displacement of 1,748 cc was 6.98 L/100 km during the 2016-2022 period, while the average fuel consumption of motorbikes was 1.96 L/100 km. By applying an annual reduction rate in fuel consumption of approximately 4%, based on current levels, and under GDP growth scenarios ranging from 8 to 11% (forecast for 2025-2030), the total reduction in CO₂ emissions is projected to range from 15.73 to 16.53 million tonnes. This reduction would meet the target set in Vietnam’s updated 2022 NDC.
Complete mitochondrial DNA sequences reveal the maternal genetic structure of Vietnamese Austroasiatic-speaking Bana, Hre, and Mnong populations
Austroasiatic, a major ethnolinguistic family in Vietnam, accounts for 90% of the census population size. Apart from the majority Kinh group, 24 other Austroasiatic minorities account for 4.67% of the population, many of which remain understudied. Here, the genetic characteristics of three Vietnamese Austroasiatic ethnic groups (Bana, Hre, and Mnong) were investigated by analysing the complete mitochondrial DNA (mtDNA) of 119 individuals. A total of 6,361 polymorphic sites were identified, with Bana exhibiting the highest molecular diversity (53.64±3.51 variants per individual). Compared to hypervariable segments (HVS), complete mtDNA sequences enhanced phylogenetic resolution and accuracy. The maternal haplogroup profile consisted of 40 lineages, with 32 of the detected lineages being population specific, six shared between two populations, and two shared among all populations. The macro-haplogroup components included B, C, F, M, N, R, and Z, with 66-80% of each population assigned to haplogroups B and M. The most prevalent haplogroups were M20 (14.29%), B5a1a (6.72%), and M74b1 (6.72%). While lineages of haplogroup F were relatively more frequent in Bana and Hre, lineages of N were exclusive to Mnong, highlighting haplogroup distinctions within the Vietnamese Austroasiatic family of the Central Highlands. These findings contribute to reconstructing the complex history of migration and settlement in Vietnam.
Genetic diversity and population structure of Dalbergia cochinchinensis Pierre ex Laness. in Vietnam's Central Highlands using inter-simple sequence repeat markers
Dalbergia cochinchinensis is classified as a critically endangered (CR) species according to the 2022 IUCN Red List [1]. This study aims to assess the genetic diversity of D. cochinchinensis populations in Kon Tum, Gia Lai, and Dak Lak, located in the Central Highlands of Vietnam, using the ISSR method. In addition, it seeks to support the conservation and propagation of D. cochinchinensis. The amplified products varied in size from 150 to 3,500 bp. Out of 101 loci examined, 93 (92.08%) were found to be polymorphic, while 8 (7.92%) were monomorphic. Most primers exhibited polymorphic loci ranging from 6 to 16. ISSR analysis revealed genetic identity levels among the three populations ranging from 0.749 (Dak Lak and Kon Tum) to 0.896 (Gia Lai and Kon Tum). The total genetic diversity of the species (HT) was calculated to be 0.261, with the average heterozygosity of the populations (HS) being 0.166. Additionally, genetic variation within the three populations of D. cochinchinensis accounted for the majority of the total genetic variation (GST=0.361 and FST=0.432), indicating significant diversity. These findings provide important insights into the genetic structure of D. cochinchinensis, which can guide conservation and propagation efforts both in Indochina and globally.
Kaposi sarcoma in the gastrointestinal tract: Challenges in diagnosis and treatment - A case report
Kaposi sarcoma is a vascular neoplasm involving the endothelial cells of blood and lymphatic vessels, associated with various aetiologies. While cutaneous manifestations are common, gastrointestinal involvement particularly in the stomach and colon is rare among HIV-infected individuals, accounting for only 0.2-1.2% of gastrointestinal malignancies. Epidemiologically, Kaposi sarcoma is more prevalent in males, typically between 50 and 70 years of age. We report a suspected case of gastrointestinal Kaposi sarcoma in a 22-year-old HIV-positive male presenting with chronic diarrhoea and significant weight loss. Upper and lower gastrointestinal endoscopy revealed dark red macular lesions in the stomach and infiltrative, ulcerative lesions with a reddish appearance in the sigmoid colon. This represents a rare case of gastrointestinal Kaposi sarcoma in a young individual, both in Vietnam and globally. Based on this case, we present a brief literature review of Kaposi sarcoma, with particular emphasis on gastrointestinal involvement in HIV-infected patients.
Insect pests and diseases of Lai Chau ginseng (Panax vietnamensis var. fuscidiscus K. Komatsu, S. Zhu & S.Q. Cai)
Panax vietnamensis var. fuscidiscus, commonly known as Lai Chau ginseng, is a high-value medicinal plant native to the mountainous regions of northern Vietnam. To develop effective management strategies for Lai Chau ginseng, this research aimed to comprehensively assess the pests and diseases affecting its cultivation. In 2024, a survey was conducted in Sin Ho, Lai Chau province. A total of 48 symptomatic plant samples were collected and evaluated based on morphological characteristics and visible symptoms. Four major symptom groups were identified: insect-induced leaf damage (32%), damping off (29%), leaf spots (20%), and root rot and wilting. Two key insect pests were identified: Chinavia hilaris (green stink bug) and Pseudococcus citri (mealybug), which caused significant damage to flowers, fruits, and petioles. Additionally, five pathogens were identified, including Cladosporium paeoniae (leaf spot), Puccinia sp. (rust), and three soil-borne fungi (Fusarium solani, Pythium ultimum, and Rhizoctonia solani), responsible for root rot and damping-off. These findings provide important baseline data for developing Integrated Pest Management (IPM) strategies to support the sustainable cultivation of Lai Chau ginseng.
Green energy generation from industrial wood waste: Pellet production from carbonised Eucalyptus saligna sawdust
This study investigated the potential of pellet production from carbonised E. saligna sawdust, processed at varying particle sizes (0.6 mm, 1.18 mm, and 2.36 mm) and utilising different organic binders. Proximate and ultimate analyses of charcoal pellets were investigated using standard test methods. E. saligna sawdust was carbonised using a cylindrical barrel metal kiln, and pelletised with a manual press machine using molasses, cow dung, and fruit waste as binding agents. The proximate and ultimate analyses of charcoal pellets were determined using American Society for Testing and Materials (ASTM). Binding agents significantly influenced moisture content, volatile matter, fixed carbon, ash content, calorific value, and sulphur content (p<0.001), while particle size had a moderate effect on select parameters, particularly fixed carbon and ash content. The highest fixed carbon (44.02%) and calorific value (4980 cal/g) were observed in cow dung-bound pellets, while fruit waste-bound pellets exhibited the lowest ash (3.82%) and sulphur content (0.12%), highlighting their environmental advantages. The interaction between binding agents and particle size was significant for moisture content and volatile matter but not for fixed carbon or calorific value. This research demonstrates an innovative approach to valorise plant waste materials and underscores the potential of local biomass for sustainable energy solutions.
Gemechu Y. Shage*, Dagnachew G. Demissu, Fikremariam H. Desalegn, Tegene T. Geta, Tatek D. Bekele, Mahelete T. Ayele, Tewabech A. Yetna, Abraham D. Gashaw, Tarekegn G. Admasu, Gemechu J. Morkato
Application of a transport organisation model based on Transit-Oriented Development: A case study of urban railway line No. 1 in Ho Chi Minh city, Vietnam
Metro line No. 1 is the first urban railway line in Ho Chi Minh city, traversing densely populated urban areas and major passenger attraction centres. While it offers the potential for modern transport connectivity, operational experience has revealed that the existing transport infrastructure in adjacent areas does not fully meet passenger travel demand and has not kept pace with the city’s rapid urban development. This study focuses on assessing the scientific basis and current state of transport organisation, with the aim of applying the Transit-Oriented Development (TOD) model to Metro line No. 1. The research develops and compares two simulation scenarios: (i) the current situation scenario, reflecting existing conditions of transport connectivity, and (ii) the TOD scenario, applying TOD-based transport organisation solutions. Transport network performance indicators analysed from the simulation results include travel time, level of service, accessibility, and traffic volume. Based on the analysis of current conditions, the study proposes solutions and evaluates their effectiveness through simulation results to formulate a set of TOD-based transport organisation measures. These proposals are expected to enhance the operational efficiency of Metro line No. 1 while promoting the sustainable development of Ho Chi Minh city’s urban areas.
Preparation and preliminary evaluation of a soothing gel containing Aloe vera and Perilla frutescens essential oil
This article presents the process of developing an innovative skincare product derived from natural ingredients, specifically Aloe vera and perilla leaf essential oil (Perilla frutescens). The product is formulated in a gel-based form, making it lightweight, non-greasy, and suitable for a wide range of skin types, including normal, oily, combination, and especially sensitive skin. By combining clean, affordable, and easily accessible ingredients, the research has successfully created a high-quality skincare solution with excellent moisturising, protective, and regenerative properties at a relatively low production cost. The gel is rapidly absorbed into the skin, providing immediate hydration while delivering essential nutrients that help maintain healthy and balanced skin. Aloe vera extract is well known for its soothing, anti-inflammatory, and healing effects, whereas perilla leaf essential oil contributes antioxidant and skin-brightening benefits. Together, these ingredients help reduce irritation, improve skin texture, and support natural skin recovery. In addition, the product incorporates nanoparticles such as gold (Au) and titanium (Ti), which enhance skin regeneration, reduce dark spots, stimulate collagen production, and promote brighter, smoother, and healthier-looking skin with long-term use.
Novel naphthalene-tetrazole butanamide derivatives: synthesis and evaluation of acetylcholinesterase inhibitory activity
Acetylcholinesterase (AChE) inhibitors constitute a well-established class of therapeutic agents that provide symptomatic relief in Alzheimer’s disease, underscoring the continued importance of developing new compounds with improved efficacy and safety profiles. In this context, five novel derivatives bearing the 4-(5-(naphthalene-2-yl)-2H-tetrazol-2-yl)-Nphenylbutanamide scaffold were synthesised through four known reactions: [3+2] cycloaddition, N-alkylation, saponification, and amidation. The purity of the compounds was confirmed by melting point analysis and thin-layer chromatography (TLC). Structural characterisation was achieved using infrared spectroscopy (IR), high-resolution mass spectrometry (HRMS), and proton and carbon nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR). The acetylcholinesterase inhibitory activity of the synthesised compounds was evaluated at five concentrations to determine their IC50 values. Compound IVa exhibited the highest inhibitory potency, with an IC50 of 467.82±10.77 μM. In addition, the inhibitory potential of the compounds was analysed in relation to their physicochemical properties, including drug-likeness and blood-brain barrier permeability, with none violating Lipinski’s rule. Molecular docking studies further revealed that the naphthalene-containing framework demonstrated strong predicted binding affinity to AChE, which may contribute to the observed inhibitory activity. These findings provide novel and valuable struct
UV/visible-light photocatalytic degradation of organic dyes using ZnO nanomaterials
In this study, ZnO nanomaterials were synthesised via a hydrothermal method and characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM)/high-resolution transmission electron microscopy (HRTEM), Brunauer-Emmett-Teller (BET), analysis and diffuse reflectance spectroscopy (DRS). The obtained ZnO exhibited a wurtzite structure, high crystallinity, mesoporosity, a large specific surface area of 107.17 m2/g, and a band gap of 3.19 eV. Photocatalytic performance was comparatively evaluated under visible and UV irradiation using methylene blue (MB) and Rhodamine B (RhB) as model dyes. ZnO achieved >90-98% degradation, with consistently faster kinetics under UV irradiation and MB degrading faster than RhB. Pseudo-first-order fits yielded k(MB)=0.027 min-¹ (Vis) vs 0.076 min-¹ (UV) and k(RhB)=0.024 min-¹ (Vis) vs 0.066 min-¹ (UV), linking structureproperty features to light-dependent activity. These results establish a clear UV/Vis comparison and underscore the applicability of hydrothermal ZnO for wastewater treatment under practical illumination.
Effect of chemical modification on the superhydrophobic properties of CT3 steel surfaces
This study systematically explores the influence of diverse chemical surface modifications on the water-repellent properties of CT3 steel substrates, focusing on the synergistic relationship between surface topography and chemical composition in realising superhydrophobic behaviour. Initially, steel samples were coated with a ZnO layer to significantly enhance surface roughness, serving as a foundation for subsequent chemical treatments. The surfaces were then functionalised with various low-surface-energy agents, including triethoxymethylsilane (MTES), polydimethylsiloxane (PDMS), 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOS), stearic acid (SA), and high-density polyethylene (HDPE). Quantitative assessment via contact angle measurements demonstrated that coatings of MTES, PFOS, PDMS, and SA successfully achieved superhydrophobicity, characterised by water contact angles greater than 150° and minimal contact angle hysteresis. Of particular interest, MTES treatment in toluene solvent not only effectively reduced the surface free energy but also promoted the formation of nanofilamentous microstructures, thereby amplifying surface roughness and hydrophobic performance. The chemically and morphologically modified surfaces were thoroughly characterised using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and detailed wettability analyses to correlate surface structure with hydrophobicity.
Parameter optimisation for single-track laser cladding using the Taguchi-Grey relational approach
The judicious selection of laser cladding (LC) process parameters is essential for the clad bead geometry. In this research, the Taguchi-Grey relational method was chosen to enhance the quality of single-track bead geometry and to perform multi-objective optimisation of process parameters. The Taguchi method was selected to construct an L16 orthogonal experiment. The impact of significant LC parameters (laser power (P), scanning speed (S), and powder feeding rate (F)) on the responses (width (W), height (H), penetration (Pene), and dilution rate) was analysed based on the analysis of variance (ANOVA). The findings indicated that the scanning speed was the most important factor affecting the ratio of layer W, H, Pene, and dilution rate of the cladding. Subsequently, grey relational analysis (GRA) was employed to consolidate the four response variables into a singular grey relational grade (GRG) for quantification and optimisation purposes. Finally, the optimum cladding process parameters were obtained. The face-centred cubic (FCC) single-phase coating was observed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to analyse the microstructure and chemical composition of the coating. Moreover, hardness measurements exhibited a gradual increase from the substrate (197 HV) to the cladding layer (224 HV), attributed to the distribution of Cr and Mo, solid solution strengthening, and microstructural refinement, demonstrating improved mechanical performance.
Prediction of maintenance workforce efficiency using neural networks, fuzzy inference system and autoregressive fractionally integrated moving average for a process industry
This study establishes the efficiency of the maintenance workforce in a process plant, utilising combined models, including artificial neural networks (ANN)-weighted aggregated sum product assessment (WASPAS) and ANNfuzzy inference system (FIS)-WASPAS. ANN models with 12 architectures and a maximum epochs ranging from 64 to 173 were the limits of the analysis. Real-life data were used to train, test and rank the different architectures. WASPAS was superimposed on the ANN model for selection and ranking purposes, while FIS rules were introduced to the ANN results to uncover the uncertainty and imprecision in the model. These results were compared with those of the autoregressive fractionally integrated moving average (ARFIMA) method. At different λ values, the 4-8-10-1 ANN architecture and the FIS with 18 rules were the fittest for the ANN-WASPAS and the ANN-FIS-WASPAS methods, respectively. The ARFIMA method revealed a coefficient of maintenance workforce efficiency of -1.8636x10-2. The constant parameter in the ARFIMA model and the root mean square error (RMSE) for the training and testing datasets are 0.9267, 0.0162, and 0.0150, respectively. In conclusion, the 4-8-10-1 ANN architecture more suitably predicts maintenance workforce efficiency than the 18-rule and ARFIMA models. This study predicts maintenance workforce efficiency, providing significant insights into the application of ANN, FIS, WASPAS, and ARFIMA models in a process industry.
Vision-enabled detection of safety helmet compliance in construction zones
In the rapidly evolving field of construction management, worker safety remains a top priority. This paper introduces an innovative vision-based system for real-time detection of helmet compliance, specifically designed for construction sites, utilising advanced computer vision techniques and machine learning algorithms within the YOLO (you only look once) framework. Our system leverages high-resolution video feeds from strategically positioned cameras to monitor adherence to safety regulations concerning helmet usage. By employing deep learning methodologies, the system effectively identifies individuals not wearing helmets, thereby significantly mitigating the risk of head injuries among workers. Our training and validation results reveal an impressive precision exceeding 97% at mAP@0.5 for both helmeted and non-helmeted individuals. Furthermore, our experiments demonstrate exceptional detection accuracy, showcasing the system’s resilience under varying lighting conditions and diverse worker movements. The consistent decrease in loss and improvement in metrics throughout training validate the effectiveness of the YOLOv8 model in enhancing recognition performance. The implications of this research extend beyond mere regulatory compliance, opening avenues for innovative applications in occupational safety management. This study highlights the critical role of technology in protecting lives and lays the groundwork for future advancements in smart construction environments.
A new meshfree method of lines for the 3D advection-diffusion equation for solute transport in porous media
The study proposes a novel Meshfree Method of Lines (MFMOL) for the numerical solution of three-dimensional advection-diffusion equations (ADEs) used to model solute transport in porous media. The method involves discretising the spatial variables of the model equations using an Augmented Radial Basis Point Interpolation Method (ARPIM), while the temporal variable remains continuous. This results in a system of ordinary differential equations (ODEs), which is numerically integrated using the MATLAB ODE solver. In solving solute transport in porous media, traditional mesh-based methods such as the Finite Element Method (FEM), Finite Difference Method (FDM), and Finite Volume Method (FVM) often encounter challenges such as numerical instabilities and distorted meshes caused by complex geometries and the presence of convective terms. To ensure accuracy, various stabilisation techniques are required, which increase computational effort, cost, and setup time. To overcome these challenges, the new MFMOL approach was proposed and applied in strong-form formulations without stabilisation techniques to solve 3D advection-diffusion problems in homogeneous and isotropic porous media. The results obtained were in good agreement with existing exact solutions, establishing the accuracy and efficiency of the new method and demonstrating its advantages over traditional mesh-based methods for solving problems involving complex geometries.
A broadband low-resolution spectrograph: SpectrumMate LR
spectrograph specifically tailored for use with small telescopes. SpectrumMate LR is designed to offer affordable and accessible spectroscopic capabilities for amateur astronomers, students, and educators, responding to the growing demand for versatile instrumentation in non-professional and educational settings. Employing a 300-grooves-per-millimetre diffraction grating together with 80 mm focal-length collimator and objective lenses, the system is optimised to analyse light across the entire visible spectrum. These optical parameters allow users to classify stars by spectral type, estimate stellar effective temperatures, and verify the transmission characteristics of astronomical filters. Laboratory and on-sky tests demonstrate SpectrumMate LR’s ability to record accurate, well-calibrated spectral data, validating its efficacy when observing a variety of both celestial and terrestrial light sources. Because all components are commercially available and assembly procedures are straightforward, the instrument fills an important niche for cost-effective spectroscopy, empowering a broader community to engage in detailed observational astronomy. By lowering financial and technical barriers, SpectrumMate LR promotes hands-on learning, encourages citizen-science contributions, and provides a practical pathway for schools, small observatories, and enthusiast clubs to expand their research and outreach activities. As a result, SpectrumMate LR stands out as an exemplary tool for introductory spectroscopy courses worldwide today.
Bismuth doping enhances the thermoelectric power of ZnO thin films via structural distortion modulation
The global energy conservation and pollution crisis is compelling the industry to seek methods for harvesting and conserving energy. Microfabrication methods of zinc oxide (ZnO) thin films also play a crucial role in affecting thermoelectric (TE) performance. This study investigates the TE properties of ZnO and Bi-doped ZnO thin films fabricated via radio-frequency (RF) magnetron sputtering. The incorporation of Bi into the ZnO lattice was systematically analysed to determine its impact on residual stress and electrical performance. Structural analysis confirms that Bi doping caused stress relaxation, reducing compressive stress from -1.00 to -0.36 GPa. Complementary insights from micro-Raman spectroscopy revealed Raman shifts, indicating an increase in defectrelated modes, specifically an intensified peak at 560 cm-1 associated with oxygen vacancy formation. The electrical conductivity of Bi-doped ZnO film reached 776.3 S/cm at 773 K, which was fourfold higher than that of pure ZnO. This enhancement in electrical conductivity played a key role in improving the power factor (PF) of TE materials. The power factor for the Bi-doped ZnO film was enhanced to 463.8 μW/mK2 at 773 K compared to pristine ZnO (314.8 μW/mK2) under the same conditions.
Yen Binh Nguyen, Trang Thuy Thi Phan, Trieu Quang Vo, Vinh Cao Tran, Thang Bach Phan, Anh Tuan Thanh Pham
Yen Binh Nguyen, Trang Thuy Thi Phan, Trieu Quang Vo, Hoa Thi Lai, Vinh Cao Tran, Thang Bach Phan, Anh Tuan Thanh Pham
Hoa Thi Lai, Thang Bach Phan, Anh Tuan Thanh Pham*
A new design of a fall detection system integrating landmark identification and deep learning techniques
This article introduces an innovative system that integrates landmark identification with deep learning to enhance fall detection accuracy and reliability. By utilising advanced computer vision techniques, such as MediaPipe for spatial recognition, the system effectively differentiates between routine movements and actual falls. The integration of landmarks with a deep learning prediction algorithm minimises false alarms, ensuring timely responses to genuine falls. Comprehensive experimentation underscores the system’s versatility across various scenarios, emphasising its potential to improve safety and independence for older adults. The training process demonstrates a steady increase in accuracy, stabilising by the 40th cycle, while error rates decline significantly during the initial cycles. Real-time experiments, involving both male and female participants aged 8 to 50, recorded a remarkable 95% detection rate of falls, showcasing the system’s effectiveness and promising future applications in elder care and smart health monitoring environments.
Estimation of radiation exposure to family members of I-131-treated patients in Tanzania using PHITS simulations
Radiation therapy using Iodine-131 (I-131) is a widely employed treatment for thyroid disorders; however, it poses potential radiation risks to patient caregivers due to gamma emissions from treated patients. This study estimates the radiation doses received by family members of patients undergoing I-131 therapy in Tanzania, where cultural practices and living conditions complicate adherence to international safety guidelines. Using the Particle and Heavy Ion Transport Code System (PHITS), exposure scenarios during hospitalisation and post-discharge phases were modelled, accounting for proximity, activity levels, and caregiver-patient interactions. These models were used to quantify the radiation exposure to family members of patients treated with I-131 in Tanzania. Results indicate that family members assisting dependent patients during hospitalisation received doses of 1.53, 2.33, and 2.99 mSv for 3700, 5550, and 7400 MBq, respectively. These doses are below the 5 mSv per episode limit but exceeding the 1 mSv annual public dose limit recommended by the International Commission on Radiological Protection (ICRP). Post-hospitalisation, the doses decreased significantly, with the highest exposure caused by close-contact activities. Meanwhile, transportation scenarios showed the exposure to be less than 1 mSv/year for short durations. Nevertheless, strict adherence to maintaining a one-metre distance and minimising the duration of close contact is emphasised. These findings provide critical insights for maintaining public health while ensuring effective thyroid cancer treatment.
Penina George Mbago*, Innocent Jimmy Lugendo
High-precision phase compensation in digital holographic microscopy via a Shack-Hartmann wavefront sensor in a telecentric configuration
Digital holographic microscopy (DHM) enables the reconstruction of three-dimensional surface profiles with nanometre-scale axial resolution. However, measurement accuracy may be compromised by phase distortions arising from the spherical aberration of the microscope objective lens and by imperfections in other optical components. In this study, we propose a method that combines a Shack-Hartmann wavefront sensor (SH-WFS) with a reference - mirror arrangement, integrated within a telecentric optical system for phase compensation. This hybrid approach, which melds physical calibration with digital correction, simultaneously reduces both global and local system errors. Consequently, it achieves precise phase correction without complex manual adjustments and maintains high stability when switching between samples. Experiments were conducted using surface-roughness standards with arithmetic mean surface roughness values (Sa) of 20.3 and 11.6 nm, measured using a ZeGage™ Pro surface-scanning device. The results showed good agreement with the reference values provided by the ZeGage™ Pro, thereby confirming the effectiveness of the proposed method. Overall, this technique markedly improves measurement accuracy in DHM and underpins the development of highly automated measurement systems, offering promising applications in precision optics.
Pham Duc Tuan, Vu Thanh Tung*, Phan Dinh Tuan
Bui Thanh Tung, Mai Linh, Pham Ngoc Thao, Duong Minh Ngoc, Pham Duc Quang*
Evaluation of the alpha-glucosidase and alpha-amylase inhibitory potential of Costus speciosus (J. Koenig) Sm. aerial parts from Vietnam
This study aimed to evaluate the inhibitory activity of α-glucosidase and α-amylase enzymes using aqueous and 40% ethanol extracts from the aerial parts of Costus speciosus harvested in Binh Phuoc province, tested in vitro. The enzyme inhibition activity was measured using α-amylase from porcine pancreas and α-glucosidase from Saccharomyces cerevisiae. Results showed that both the aqueous extract and the ethanol extract from the aerial parts of Costus speciosus showed significant α-glucosidase inhibition, with IC50 values of 18.51 and 77.25 μg/ml, respectively. Both extracts demonstrated lower IC50 values compared to the positive control, acarbose (IC50=122.20 μg/ml). For α-amylase inhibition, the aqueous extract and ethanol extract exhibited relatively low inhibition rates of 3.79 and 3.12%, respectively, compared to acarbose, which had an IC50 of 50 μg/ml for α-amylase inhibition. The study demonstrated that the aqueous and ethanol extracts of the Costus speciosus aerial parts exhibited in vitro inhibitory effects on α-glucosidase. However, the extracts showed poor inhibitory effects on α-amylase activity. These findings provide additional scientific evidence supporting its potential use in Vietnam for its hypoglycaemic properties.
Microplastics in Vietnamese seafood and potential human exposure: A mini-review
In this article, we review the occurrence and characteristics of microplastics (MPs) in marine organisms used as food (seafood) from Vietnam and assess the consumers’ health risks related to MPs-contaminated seafood. Twentyone marine species of fish, shrimp, and bivalves were reported to accumulate MPs in their tissues, with the highest abundance in fish (Decapterus maruadsi, 87 items/individual) and the lowest abundance in hard clam (Meretrix lyrata, 0.25 items/individual). The mean values of MPs abundance (items/g wet weight - ww) were 2.44, 0.73, and 0.85 in fish, shrimp, and bivalves, respectively. Fibre was the most common shape of MPs, but fragmented MPs were also observed in the tissues of marine organisms, and beads were only found in shrimp. Various MPs colours and more than ten MPs polymers were noted in the seafood. The estimated daily intake of microplastics (pEDI) was low (<1) based on the consumption of each seafood group, but it became high (>1) when pooled for all seafood. The total MPs that one person can ingest from seafood could be up to 22,876 items annually. Further quantitative studies of MPs in other kinds of food, spices, drinks, and air in Vietnam are necessary for a comprehensive assessment of human health risks associated with MPs exposure.
Trung-Hau Nguyen, To Thi Hien, Thanh-Son Dao
In silico identification of potential anti-monkeypox virus agents from Hypericum sampsonii
Monkeypox (Mpox), an emerging zoonotic infectious disease caused by the monkeypox virus (MPXV), has become an escalating global health threat. A wave of outbreaks began in 2022 and continued into 2024. Currently, no vaccines or FDA-approved specific treatments exist for MPXV, making the discovery of effective antiviral drugs crucial. The A48R protein, a thymidylate kinase (TK), is recognised as a promising target for MPXV drug development due to its distinctive active site structure compared with the human homolog. Hypericum sampsonii Hance, a traditional medicinal herb from the Guttiferae family, has demonstrated various biological activities, including antiviral properties. By leveraging the natural compounds derived from H. sampsonii, this study aimed to identify potential inhibitors of the MPXV-TK protein. Molecular docking and dynamics simulations revealed two compounds, LTS0126561 and LTS0259892, with strong affinity for the TK active site. In silico pharmacokinetic and toxicological assessments indicated that both compounds are suitable candidates for oral drug development. These identified compounds provide a basis for developing antiviral agents against MPXV and other Orthopoxviruses. However, further experimental validation of these lead compounds is required to confirm their predicted antiviral activities.
Factors associated with quality of life among non-small cell lung cancer patients treated with first-line targeted therapy in Vietnam: A study using the EORTC QLQ-C30 scale
A cross-sectional study was conducted using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) scale to measure the quality of life (QoL) of 310 nonsmall cell lung cancer (NSCLC) patients with EGFR mutations receiving first-line targeted therapy at the Vietnam National Cancer Hospital from October 2022 to December 2023. A Tobit regression model was employed to identify factors associated with the QoL of NSCLC patients. The global health status of NSCLC patients was rated at 62.88 points, with financial difficulties scoring 51.08 points. Among the functional scales, physical functioning scored the highest at 85.72 points, followed by role functioning (79.57), cognitive functioning (78.66), social functioning (71.72), and emotional functioning, which scored the lowest at 65.83 points. Regarding the symptom scales, insomnia scored the highest at 35.48 points, followed by fatigue (31.33), pain (25.11), diarrhoea (23.33), appetite loss (17.1), and dyspnoea, which scored the lowest at 4.62 points. Factors such as low income, residing in rural areas, and experiencing fatigue symptoms have a detrimental effect on the QoL of NSCLC patients. Improving fatigue symptoms, supporting income for low-income patients, and offering financial assistance, such as providing complimentary bus tickets and meals at the hospital, can alleviate financial strain and prolong the duration of support for NSCLC patients.
Chinh Van Nguyen*, Linh Dieu Hoang, Huong Thi Thanh Tran, Kiet Tuan Pham Huy
Natural dishwashing liquid from fermented grapefruit peel solution
The release of significant amounts of chemical detergents into the environment due to human activities raises concerns regarding environmental issues and human health. This study investigates the development of an eco-friendly dishwashing liquid derived from a fermented grapefruit peel solution, aiming to reduce organic waste and promote sustainable cleaning alternatives. The formulation involves fermenting a mixture of three parts grapefruit peel, one part brown sugar, and ten parts water in a sealed container for one month. The resulting solution effectively removes 89.2% of lard from plastic surfaces, eliminates 96.6% of bacteria, and produces foam comparable to that of commercial dishwashing liquids. Although no hydrolytic enzyme activity was detected using the well diffusion agar method with the respective substrates, the detergent effect of the fermentation broth likely arises from organic acids and biosurfactants, rather than from hydrolytic enzymes. The pH value of fermentation fluid decreased to 3 to 4.5 from the initial neutral pH. Consumer feedback highlights its potential as a safe, skin-friendly, and environmentally sustainable substitute for synthetic cleaners, contributing to broader environmental conservation efforts.
Hong Nguyen Pham, Si Hung Ho, Thi Huong Len Le, Thi Minh Xuan Nguyen*
Survey of species composition in the Asteraceae family with value as animal feed in Chieng Ngan commune, Son La city, Son La province
This study investigates the species composition and ethnobotanical value of Asteraceae family plants used as livestock feed in Chieng Ngan commune, Son La city, Son La province (prior to the administrative merge). Fieldwork was conducted from July 2023 to May 2024 using ethnobotanical methods, including participatory observation, semistructured interviews, and focus group discussions with 150 local informants from the Thai ethnic group. A total of 44 plant species used for livestock feed were recorded, representing 34 genera. Leaves were the most commonly utilised plant part. All 44 species were used to feed goats; 33 species were used for buffaloes and cattle, and 15 species for pigs. Nine Asteraceae species had a use value (UV) index of ≥0.90. Two species were also employed in traditional remedies for livestock. The life forms of Asteraceae species were classified as follows: SB=31.82% Hp+29.55% Th+15.91% Ch+15.91% Hm+6.82% Na. The majority of species originated from tropical Asia (77.27%), with additional floristic elements identified. Asteraceae species were found across diverse habitats, including farming areas and grasslands (28 species), shrublands (24 species), limestone forests (19 species), secondary forests (17 species), and home gardens and fields (11 species). These findings highlight the significance of traditional knowledge in livestock feeding practices and underscore the potential of Asteraceae plants as valuable feed resources in local agroecosystems.
Thi Lien Vu*, Di Xay Van Son Thong, Duc Toan Vu, Thi Thanh Ha Hoang
Preparation of preservative product for Xuong Com Vang longan based on chitosan and the oligochitosan-iodine complex
Longan (Dimocarpus longan Lour.) is a tropical fruit characterised by a short shelf life, which necessitates the application of postharvest preservation methods to reduce losses during distribution and consumption. A preservation mixture based on chitosan (CS) and the oligochitosan-iodine (OC-I2) complex was developed and evaluated for postharvest application in longan fruit storage. Ultraviolet-visible spectroscopy, X-ray diffraction, and Fouriertransform infrared spectroscopy confirmed that 2% H2O2 hydrolysis broke the β-1,4 glycosidic bond of CS without altering the OC structure. OC formed a complex with I2 through -NH2 and -OH groups. The chitosan-(oligochitosan-iodine) (CS-(OC-I2)) mixture at 9.00-22.5 g/l extended the shelf life of Xuong Com Vang longan fruits from 5 days (control) to 15-20 days at room temperature. Treated fruits showed reduced respiration rates, microbial density, weight loss, total soluble solids, browning index, and disease index, while maintaining greater fruit hardness and stabilising total soluble solids. These results indicate that the CS-(OC-I2) mixture is a promising preservative for longan and potentially other fruits, with the capacity to reduce postharvest losses during storage and distribution.
Du Duy Bui*, Tho Phuoc Tran, Tuan Nghiem Anh Le, Giang Ngoc Doan
Isolation and structural elucidation of xanthone derivatives from the pericarp of Garcinia mangostana L.
In Vietnam, Garcinia mangostana L. is commonly referred to as “Mang Cut” in Vietnamese, renowned not only as the “queen of fruits” but also for its various medicinal properties, particularly the shell of the mangosteen fruit. In traditional medicine, the shell of G. mangostana has long been employed to treat infections, diarrhoea, dysentery, and inflammation. Previous studies have shown that it possesses a variety of bioactive properties, including antibacterial, antifungal, anti-allergic, anti-inflammatory, anti-tumour, and antiviral effects, attributed to xanthones. In our research, a phytochemical analysis of the ethyl acetate extract from the shell of G. mangostana led to the identification of several compounds, including garcinone C (1), garcinone D (2), bannaxanthone A (3), 8-deoxygartanin (4), and mangostanol (5). Their structures were elucidated through a comprehensive examination of ESIMS, 1D, and 2D NMR spectroscopic data. This study reports for the first time of bannaxanthone A (3) being isolated from this plant. These findings contribute to our understanding of G. mangostana and highlight its potential as a valuable herbal resource that may provide secondary compounds for the treatment of non-communicable diseases in the future.
Pham Thanh Huyen, Nguyen Minh Khoi, Nguyen Van Tai*, Dang Viet Hau*
Chemical composition and antioxidant activity of the fruit essential oil of Xanthium strumarium L. cultivated in Hai Duong province, Vietnam
Xanthium strumarium L., a species in the Asteraceae family, is well known for its use in traditional medicine. This study aimed to identify the chemical composition and evaluate the antioxidant activity of the essential oil (EO) extracted from the fruits of X. strumarium collected in Hai Duong province, Vietnam. The EO was obtained via steam distillation and analysed using gas chromatography-mass spectrometry (GC-MS). The results revealed 15 major compounds accounting for 93.88% of the total oil content. The dominant constituents included m-tolualdehyde (12.11%), 1,2-benzenedimethanol (11.87%), p-tolualdehyde (9.94%), caryophyllene oxide (9.28%), and endo-borneol (8.91%). The major chemical groups were oxygenated sesquiterpenes (26.79%) and aromatic compounds (39.72%). The antioxidant activity of the EO was assessed using three methods: ferricyanide reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 2,2’-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays. The EO demonstrated strong radical scavenging activity, comparable to ascorbic acid, with IC50 values of 22.8 μg/ml (DPPH) and 22.1 μg/ml (ABTS). These findings indicate that the fruit EO of X. strumarium possesses a rich chemical profile and significant antioxidant potential, suggesting promising applications in pharmaceuticals and functional foods.
Investigating the preparation of oxime derivatives of azacrown ethers containing piperidine-4-one heterocycles under microwave irradiation
The use of multi-component reactions to simultaneously synthesise crown ethers and nitrogen-containing heterocycles is a synthetic approach that has attracted significant interest. With nitrogen heterocycles embedded in their structures, azacrown ethers can participate in various reactions to modify their structures for diverse applications. Herein, the preparation of azacrown ethers containing the piperidine heterocycle, based on a modified Petrenko-Kritschenko condition, is reported. The oximation of azacrown compounds was investigated under conventional reflux conditions and microwave irradiation at different temperatures. Physicochemical analyses, including 1HNMR, 13CNMR, and HRMS, were employed to elucidate the structures of the synthesised compounds. The experimental data demonstrated that microwave irradiation is an effective approach for oximation, reducing the reaction time to 20 minutes at 80°C and affording high yields (89-92%).