Vietnam Journal of Science, Technology and Engineering

Synthesis of novel fluorinated flavonols via Algar-Flynn-Oyamada reaction

Le Thanh Huy — 2026-09-15

Flavonols have attracted considerable attention due to their diverse biological effects. However, naturally occurring flavonols are typically present only in low concentrations, with fluorine-containing flavonols being especially rare. In that respect, the construction of diverse flavonol analogues is attractive to synthetic chemists. As part of our efforts to develop fluorinated flavonols, a series of fifteen fluorinated flavonols (1-15) were synthesised via the oxidative cyclisation of 2′-hydroxychalcones with hydrogen peroxide in an alkaline ethanol solution, using the Algar-Flynn-Oyamada (AFO) reaction. Despite the relative simplicity and convenience of the AFO reaction, the isolated yields of the fluoro-substituted flavonols were relatively modest, ranging from 16 to 51%. The cyclisation yields of flavonols were found to be favourable in the presence of fluorine substituents at the 2′- or 3′-position in the B ring. The structures of the fluorinated flavonols were elucidated by nuclear magnetic resonance (NMR) and mass spectrometry (MS) data. It is of interest to note that this work, for the first time, demonstrates the synthesis of six novel fluorinated flavonols (7, 8, 12-15) through the application of the AFO approach.

Balancing free-volume and hydrogen-bond/ion-pair interactions: Plasticisation of cassava starch with glycerol-monoethanolamine deep eutectic solvents

Chien Van Nguyen, Mai Thi Pham, Phuong Thi Hoang* — 2026-09-15

Thermoplastic cassava starch was plasticised with deep eutectic solvents (DES) based on choline chloride (ChCl), glycerol (Gly), and monoethanolamine (MEA) to balance free-volume creation and hydrogenbond/ion-pair junctions. Binary (ChCl:Gly 1:3; ChCl:MEA 1:3) and ternary ChCl:Gly:MEA (1:1:1; 1:1:2; 1:2:1) DES at 25 wt% were melt-compounded and assessed by processing metrics, FTIR-ATR, dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), X-ray diffractometry (XRD), wettability (Owens-Wendt-Rabel-Kaelble (OWRK)), and 56-day ambient aging (23±2°C, 50±5% RH). Gly-rich systems enhanced flow but depressed cohesion, whereas MEA-rich systems strengthened interchain junctions. The ternary ChCl:Gly:MEA 1:1:2 delivered the best process-structure-property balance, combining high melt processability with tensile strength (TS)~2.9 MPa and elongation at break (ε_b)~195% (n=5) and displaying the lowest 56-day ductility loss (Δε_b~-17%) compared with glycerol controls (~-50%). FTIR (O-H/N-H red-shift and broadening), together with SEM fracture morphology and OWRK-derived surface energetics, supports a dual-mode plasticisation mechanism in which MEA-enabled junctions counterbalance Gly-induced free volume, thereby stabilising the amorphous phase and is consistent with reduced retrogradation without sacrificing strength. This composition-structure map identifies ChCl:Gly:MEA (1:1:2) as a composition window that stabilises starch-based thermoplastics (TPS) mechanical performance during ambient aging.

N-heterocycle-containing sulfonamides as potential inhibitors of the cancer-related Vps34 enzyme: A theoretical study

2026-09-15

This work provides a theoretical assessment of 30 N-heterocycle-bearing sulfonamide derivatives as prospective inhibitors of the cancer-associated enzyme Vps34, a central regulator of autophagy and tumour development. Molecular docking simulations carried out with AutoDock Vina ranked the compounds by binding affinity, grouping them into weak, moderate, and strong binders. Six derivatives (8, 12, 13, 14, 18, 30) displayed the most favourable interactions with key active-site residues such as phenylalanine PHE612, isoleucine ILE634, tyrosine TYR670, leucine LEU750, ILE760, lysine LYS636. These leading candidates were subsequently evaluated for druglikeness using Lipinski’s Rule of Five and oral bioavailability via SwissADME radar plots, all of which indicated suitable profiles. Complementary ADMET predictions from Deep-PK supported acceptable pharmacokinetic behaviour and manageable safety risks. Furthermore, molecular dynamics simulation were also carried out to gain insights into the interactions between Vps34 and compound 30. Throughout the studies, compound 30 emerged as the most promising lead, combining strong binding affinity with favourable physicochemical features, high predicted oral bioavailability, and favourable protein interaction profile. Accordingly, additional in vitro and in vivo investigations are needed to fully establish the therapeutic potential of sulfonamide scaffolds, especially compound 30, as Vps34-targeted anticancer agents.

Impurity profiling in pharmaceuticals and its regulatory requirements for ensuring product quality and safety

Moin Shaikh — 2026-09-15

Impurities, whether organic, inorganic, or residual, are unavoidable components that may arise during the synthesis, formulation, or storage of active pharmaceutical ingredients (APIs) and finished products. Even trace levels of these unwanted substances can significantly influence a drug’s efficacy, stability, and patient safety. Therefore, impurity profiling has become an integral part of modern pharmaceutical quality assessment, focusing on the identification, quantification, and control of impurities to ensure product reliability and regulatory compliance. Regulatory authorities across the globe, including the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), the United States Food and Drug Administration (USFDA), and the European Medicines Agency (EMA), have established specific guidelines that define impurity thresholds, analytical validation requirements, and reporting standards. These frameworks help pharmaceutical manufacturers maintain consistent product quality and mitigate toxicological risks. The present review provides an overview of the regulatory aspects governing impurity profiling, outlines current global guidelines, and discusses the analytical and toxicological considerations essential for developing safe and compliant pharmaceutical products.

Transport planning based on the transit-oriented development model in railway station areas: Lessons learned and applications in the context of Ho Chi Minh city

Thai Hong Nguyen — 2026-09-15

This article reviews and synthesises international experience and related studies on transport planning
under the transit-oriented development (TOD) model at high-speed rail (HSR) and metro stations and
compares them with existing policies and development plans in Ho Chi Minh city. Based on this foundation
and combined with quantitative assessments and microsimulations of transport organisation around
Phuoc Long station, the study proposes a set of TOD-oriented strategies for HSR and metro stations in
the city. These include high-density and mixed-use urban planning, optimisation of public transport
connectivity, promotion of green mobility, investment in modern transport infrastructure, development
of high-quality public spaces, and improvements in traffic management. Simulation results comparing two
This article reviews and synthesises international experience and related studies on transport planning under the transit-oriented development (TOD) model at high-speed rail (HSR) and metro stations and compares them with existing policies and development plans in Ho Chi Minh city. Based on this foundation and combined with quantitative assessments and microsimulations of transport organisation around Phuoc Long station, the study proposes a set of TOD-oriented strategies for HSR and metro stations in the city. These include high-density and mixed-use urban planning, optimisation of public transport connectivity, promotion of green mobility, investment in modern transport infrastructure, development of high-quality public spaces, and improvements in traffic management. Simulation results comparing two scenarios (existing conditions and TOD-oriented transport planning) demonstrate that the TOD scenario yields significantly better performance. Projected passenger volumes increase substantially, vehicle speeds improve, and both delay and total travel time are reduced. These findings underscore the crucial role of TOD-oriented transport planning in enhancing the operational efficiency of public transport systems and improving the quality of the urban environment surrounding railway stations.yields significantly better performance. Projected passenger volumes increase substantially, vehicle speeds
improve, and both delay and total travel time are reduced. These findings underscore the crucial role of
TOD-oriented transport planning in enhancing the operational efficiency of public transport systems and
improving the quality of the urban environment surrounding railway stations.

Operations, similarity measures, and rough-set approximations for uncertain sets

Takaaki Fujita — 2026-09-15

An uncertain set assigns a generalised uncertainty value to each element, thus providing a single membership-function template that encompasses many degree-based models, including fuzzy, intuitionistic fuzzy, neutrosophic, and plithogenic sets [1]. Building on this unified viewpoint, we investigate three core components of uncertainty-aware reasoning: algebraic operations, similarity measures, and rough-set-style approximations. First, for a fixed uncertainty model M whose degree domain is equipped with a De Morgan lattice structure, inclusion, complement, union, intersection, difference, and level-set (α-cut) constructions are defined for M-type uncertain sets. Second, the author introduces an axiomatic notion of an uncertain similarity measure and provides concrete families, including normalised L1- and Chebyshev-type similarities, together with basic properties and reductions to familiar formulas in classical special cases. Third, uncertain rough sets are defined via M-valued relations and corresponding lower/upper approximation operators, and the resulting framework is shown to subsume standard fuzzy rough sets and component-wise neutrosophic rough sets. Finally, a categorical extension based on functorial sets is developed, obtaining functorial rough sets whose approximation operators satisfy naturality with respect to morphisms, thereby enabling the compositional transport of rough approximations across changing universes.

Proactive forecasting of student academic outcomes via Random Forest and cumulative learning data

Tri Nhut Do — 2026-09-15

This study develops a Random Forest-based predictive framework to forecast course outcomes for information technology students at Binh Duong University. Using institutional academic records, key features such as course codes, instructor identifiers, and encoded student IDs were combined with demographic data through a standardised preprocessing pipeline. To ensure robust validation, the experimental design utilised a strict data split (64% for training, 16% for validation, and 20% for testing) alongside 5-fold crossvalidation for hyperparameter tuning. The final model achieved an exceptional overall accuracy of 0.974 and a Receiver Operating Characteristic (ROC) Area Under the Curve (AUC) of 0.982. The framework is designed to address both course outcomes and Course Learning Outcome (CLO) attainment. Crucially, it attained a recall of 0.838 for the minority “Fail” class, demonstrating strong practical value for early risk detection. Feature-importance analysis confirmed the dominant influence of course- and instructor-related variables alongside cumulative student histories, ensuring high interpretability. By providing reliable predictions of course outcomes, the framework supports academic advisers in designing timely interventions. Ultimately, this research highlights the significant potential of institutional data for advancing educational decisionmaking and academic management.

Experimental and numerical study on the influence of explosive charge length on the performance of explosively formed projectiles

Hong Quan Pham*, Van Minh Do, Dinh Thanh Tran — 2026-09-15

Understanding how explosive charge length affects the formation and terminal performance of explosively formed projectiles (EFPs) is crucial for designing efficient warheads. In this study, a 54-mm EFP warhead comprising an oxygenfree high-conductivity (OFHC) copper liner and C4 explosive was investigated. Eleven configurations with charge lengths ranging from 0.7 to 1.7 times the charge diameter were analysed using ANSYS Autodyn simulations and the Modified Johnson-Cook model. An experimental test at l/d=1.2 impacting a steel target validated the simulation. The results show that projectile velocity, penetration depth, and diameter increase with charge length up to 1.2-1.4d, yielding EFPs with stable, aerodynamic shapes. Beyond this range, performance plateaus, marking the onset of geometric saturation where added explosive mass does not enhance the projectile’s kinetic energy. The experimental velocity deviated by less than 2.3% and the penetration diameter by less than 5.7%, indicating that the proposed model agrees well with the experimental results. These findings provide practical guidance for optimising EFPs warhead design.

A comprehensive review on propagation techniques of the medicinal herb Ocimum tenuiflorum L.

Thi-Hoan Luong — 2026-09-15

Ocimum tenuiflorum L. (holy basil) is an economically important medicinal plant widely valued for its diverse therapeutic properties and applications in traditional medicine, food, cosmetics, and pharmaceuticals. The growing global demand for holy basil and its essential oil has driven interest in efficient propagation methods to ensure a consistent supply of high-quality planting materials. This review provides a comprehensive analysis of sexual propagation, clonal propagation, and tissue culture techniques, critically evaluating their advantages, limitations, and scalability for commercial production. Key production bottlenecks, including low seed germination uniformity, limited rooting efficiency in cuttings, and high tissue culture costs, are identified, and strategies are proposed to optimise propagation efficiency and reduce costs. These insights provide a foundation for future breeding programs, sustainable cultivation, and industrial applications of O. tenuiflorum.

Xanthine oxidase inhibitory effect of formula Er-miao tang combined with inhibitory and antioxidant activities of Phyllanthus amarus L. and Orthosiphon stamineus Benth.

Hoang Oanh Hua*, Thi Lan HuongTran — 2026-09-15

This study aimed to evaluate the xanthine oxidase (XO) a modified traditional formula, Er-miao tang, combined with Phyllanthus amarus L. and Orthosiphon stamineus Benth. The goal was to explore a complementary approach utilising locally available medicinal plants. XO inhibitory activity was assessed using Noro’s spectrophotometric method, while antioxidant capacity was evaluated via the DPPH radical scavenging assay. Both water decoction and 40% ethanol extracts of the combined formula were tested. The combined formula showed stronger XO inhibition than Er-miao tang alone. The 40% ethanol extract exhibited the highest activity (IC₅₀=88.61 μg/ml), followed by the water decoction (IC₅₀=93.78 μg/ml), compared to Er-miao tang alone (IC₅₀=110.97 μg/ml). Both the water extract and the 40% ethanol extract of the formulation demonstrated antioxidant activity, with IC₅₀ values of 65.33 and 53.25 μg/ml against DPPH radicals, respectively. The combination of Er-miao tang with P. amarus and O. stamineus enhances XO inhibitory and antioxidant activities, supporting further investigation of the formulation as a potential source of inhibitory constituents.

Germline diagnosis of Lynch syndrome in mismatch repair-deficient colorectal cancer: A case series from Bach Mai Hospital

Phuc Hong Dinh — 2026-09-15

Lynch syndrome (LS) is the most common hereditary cause of colorectal cancer (CRC) but is frequently missed by family-history-based criteria. We report an immunohistochemistry (IHC)-triggered, next-generation sequencing (NGS)-confirmed diagnostic pathway for LS in patients with mismatch repair-deficient (dMMR) CRC at Bach Mai Hospital in 2025. Three BRAF V600E wild-type dMMR CRC patients underwent germline NGS, and a molecular diagnosis of Lynch syndrome was established in two. Case L1, a 41-year-old man with a poorly differentiated descending-colon adenocarcinoma, carried a pathogenic MLH1 frameshift variant (c.793del, p.Arg265ValfsTer3). Case L2, a 33-year-old man with synchronous transverse-colon and splenic-flexure tumours, carried a likely pathogenic MSH2 missense variant (c.1865C>G, p.Pro622Arg); a preoperative biopsy showed proficient MMR whereas the resection showed MSH2/MSH6 loss, illustrating clonal MMR heterogeneity. The third patient (Case N1) had MLH1/PMS2 loss but no detectable germline variant, consistent with a possible Lynch-like syndrome pending methylation testing. In each patient, the IHC loss pattern correctly directed germline testing. These cases support germline testing of all dMMR colorectal cancers independent of family history and highlight the genetic-counselling and cascade-testing implications for probands and at-risk relatives.

Leiomyosarcoma of the colon: A challenging diagnosis in young women - A case report

Anh Vu Hong — 2026-09-15

Leiomyosarcoma (LMS) of the colon is an extremely rare colorectal malignancy, accounting for less than 0.1% of all colorectal cancers. The clinical symptoms of colonic LMS are often vague and nonspecific, including abdominal pain, changes in bowel habits, rectal bleeding, or an abdominal mass, which makes early diagnosis difficult. The majority of cases occur in middle-aged adults, with a slight male predominance. We report a rare case of colonic LMS in a young woman, whose clinical symptoms closely resembled those of a ruptured bleeding ovarian cyst or ectopic pregnancy, leading to an initial misdiagnosis. The definitive diagnosis was made through laparoscopic surgery and histopathological biopsy. Histopathological examination using histopathological examination (H&E) staining and immunohistochemistry (IHC) confirmed colonic LMS. Metastatic involvement was identified in 7 out of 11 regional lymph nodes. Our report highlights a very rare case of LMS involving the rectum and sigmoid colon, underscoring the diagnostic challenge in young female patients and emphasising the importance of surgical exploration and pathological confirmation in atypical pelvic presentations.

Multiple renal artery reconstruction in a high-volume living donor kidney transplant centre

Khai Ninh Viet*, Dang Do Hai, Tuan Hoang, Trung Nguyen Duc — 2026-09-15

Kidney transplantation (KT) is the most effective treatment for end-stage renal disease; however, certain challenges (e.g. multiple renal arteries) may lower outcomes. We aimed to describe a single-centre experience with reconstruction techniques and outcomes. This retrospective study included 82 patients who underwent KT with multiple renal arteries out of a total of 762 cases between April 2018 and August 2022, with demographic data and renal vessel characteristics collected. The main outcomes were operation time, graft function, complications, and graft survival, and these were compared with a single-artery control group. Most patients had two arteries (82.9%). There were significant differences in warm ischemic time, reconstruction time for arterial anastomosis, and overall operation time compared with the control group (p<0.05). One patient (1.2%) developed a pseudoaneurysm requiring reoperation, with no grade 4 or higher complications. Graft function remained stable, and no patients experienced graft failure. The efficacy and safety of KT in patients with multiple renal arteries were acceptable.

Evaluation of Bile salt hydrolase activity and cholesterol-binding ability of lactic acid bacteria isolated from milk and meconium

2026-09-15

Lactic acid bacteria (LAB) have long been recognised as probiotics that support the digestive system and help maintain host health. Beyond their typical features, such as tolerance to low pH, high salt concentrations, adherence to host tissues, and diverse metabolic capabilities that produce a range of beneficial compounds, LAB strains with bile salt hydrolase (BSH) activity have been implicated in cholesterol reduction. This study isolated eight strains of LAB from human milk, cow’s milk, and meconium. The eight LAB strains were then investigated for BSH production, BSH activity, and cholesterol-binding properties. Notably, all eight strains demonstrated robust bile salt tolerance to ox gall and bile salts (including cholic acid and taurocholic acid) after 20 hours of cultivation. BSH enzyme activity varied, ranging from 0.28 to 18.04 U/ml, while cholesterol binding ranged from 34.38 to 108.02 µg/ml. Among the strains evaluated, SMB68, SMB33, and LS13 stood out as superior candidates; these strains were identified as Ligilactobacillus salivarius, Enterococcus faecalis (E. faecalis), and Lactiplantibacillus plantarum, respectively. Cholesterol-binding values reached 108.02, 107.33, and 81.94 µg/ml, respectively. These strains hold potential for application in products aimed at preventing lipid-related diseases.

Antibacterial and antioxidant activities of six plants consumed by the Tonkin snub-nosed monkey (Rhinopithecus avunculus) in Khau Ca area, Tuyen Quang province

Anh Le Hoang Phuong, Anh Nguyen Thi Lan*, Ha Do Minh — 2026-09-15

The Tonkin snub-nosed monkey (Rhinopithecus avunculus) is an endemic, critically endangered primate that inhabits karst forests in Vietnam. Its survival depends on a variety of food plants, making an understanding of their bioactive properties crucial for species conservation and nutritional ecology. This study aimed to evaluate the antibacterial and antioxidant activities of six plants consumed by the species in the Khau Ca area, Tuyen Quang province. Methanolic leaf extracts were analysed using standard assays, including DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′- azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) assays for antioxidant capacity and the agar dilution method for antibacterial activity. The results revealed that Polyalthiopsis floribunda extract is the most promising candidate for development into a broad-spectrum antimicrobial agent due to its consistent bactericidal activity against the tested Gram-negative and Gram-positive bacterial strains. The extracts were categorised into two main groups based on their mechanism of action: a bactericidal group (Polyalthiopsis floribunda) and a bacteriostatic group (Debregeasia squamata and Meliosma paupera). Both Celtis philippensis and Radermachera hainanensis extracts had the lowest IC₅₀ values among the six extracts, demonstrating strong antioxidant activity and comparable potential in both DPPH and ABTS assays. These findings highlight the ecological significance of these plants in supporting health maintenance and survival of the largest population of Tonkin snub-nosed monkeys in Vietnam.