Vietnam Journal of Science, Technology and Engineering - C
Tạp chí của Bộ Khoa học và Công nghệ
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%).
Direct non-medical costs and influencing factors of patients with non-small cell lung cancer treated with targeted therapy: A cross-sectional study in Vietnam
To estimate the direct non-medical costs and related factors for patients with non-small cell lung cancer (NSCLC) with estimated glomerular filtration rate (EGFR) mutations who received first-line targeted therapy, a crosssectional study was conducted from October 2022 to December 2023. Interviews were conducted with 310 NSCLC patients at the Vietnam National Cancer Hospital in Tan Trieu. The mean total direct non-medical costs for NSCLC patients were VND 832,989 per month, accounting for 3.6% of the mean total costs and 29.6% of the average income of NSCLC patients. The highest proportion of patients incurred expenses for transportation (98.7%), meals (90.0%), and lodging (39.0%). Costs for transportation (VND 591,525, accounting for 71.0%), meals (VND 155,580, accounting for 18.7%), and lodging (VND 85,884, accounting for 10.3%) were reported. Meal and lodging costs increased with the duration of hospital visits (p<0.001). Factors such as residing in rural areas, frequency of caregivers, and duration of hospital visits were found to affect the direct non-medical costs of patients with EGFR-mutated NSCLC (p<0.05). Organisations and individuals should support NSCLC patients by offering free or discounted meals, lodging, and transportation. This assistance can help reduce the out-of-pocket burden on patients and prevent them from falling into poverty.
Thi Thai Hoa Nguyen, Thi Thai Hoa Nguyen
Study on the reuse of high-silica by-product from Lionas Metals Plant to partially replace cement in concrete production
This study investigates the reuse of high-silica by-product (HSB) from the Lionas Metals Plant as a partial replacement for cement in concrete production. Four mixtures with 0, 10, 20, and 30% cement replacement by HSB were designed using the absolute volume method at a fixed water-to-binder ratio of 0.45. The study evaluated the effects of HSB on concrete properties, including fresh and dry unit weights (UW), water absorption (WA), compressive strength (CS), ultrasonic pulse velocity (UPV), thermal conductivity (TC), and rapid chloride ion penetration (RCPT). Results showed that increasing the HSB content led to a reduction in both fresh and dry UWs. WA decreased with longer curing times and higher HSB content, while resistance to chloride ion penetration improved significantly. The HSB content resulted in higher CS and UPV while reducing WA, TC, and RCPT. Higher HSB content resulted in greater CS and durability, with the 30% HSB mixture demonstrating outstanding 28-day performance: a maximum CS of 65.04 MPa, the highest UPV of 4902 m/s, the lowest WA of 1.14%, a reduced TC of 1.96 W/(m×K), and an extremely low RCPT value of 179 Coulombs. Microstructural analysis supported these observations. The findings demonstrate HSB’s effectiveness in improving concrete performance and confirm its viability for sustainable concrete production.
Multi-stage drying processes in Clitoria ternatea flower extracts: A method to intensify anthocyanins for botanical dye production
This study presents an optimised multi-stage drying process for Clitoria ternatea (butterfly pea) flower extracts to enhance anthocyanin concentration for sustainable botanical dye production, addressing the need for nontoxic and environmentally friendly dyeing methods. This method preserves anthocyanins through pre-treatment (cleaning, alkaline stabilisation, and blanching) before a sequential drying process at 70, 60, and 50°C. Each stage gradually reduced moisture while preserving pigment stability. Anthocyanin levels were measured via UV-Vis spectrophotometry, and colour stability was tested under natural sunlight to mimic real-world conditions. The optimised protocol increased anthocyanin concentration by 40% (from 45 to 63 mg/l) while maintaining moisture content at 5-7%, ensuring long-term stability. Notably, the treated extracts retained vibrant colour under sunlight with only minor fading, proving the method’s viability for dye production. Additionally, the study introduces a scalable, eco-friendly process for producing stable anthocyanin dyes, promoting sustainable practices in textiles, cosmetics, and food production while meeting the demand for environmentally friendly alternatives.
TABLE OF CONTENTS IN 2025
Identification of grain size and mineral distributions in the surface sediments of Red river estuaries in Vietnam
The mineral composition and grain size of 45 surface sediment samples from the estuaries of the Red River system were analysed to assess the dynamics and origin of the sediments. Five types of sediments are distributed in river mouths, which are coarse silt, very fine sand, very coarse silt, fine sand, and medium silt. The mineral contents in the sediment were as follows: quartz 46.0%, illite 18.3%, kaolinite 11.8%, chlorite 6.4%, feldspar 6.0%, goethite 4.4%, calcite 1.9%, gibbsite 1.7%, and amphibole 1.4%. Between grain size parameters and mineral compositions were positive and negative correlations. The positive correlations were between S0 and illite, kaolinite, goethite, calcite; between Md and quartz, feldspar, amphibole; between illite, kaolinite, chlorite, goethite together. The negative correlations were between quartz, feldspar, Md with illite, kaolinite, chlorite; between goethite with quartz, feldspar, Md; between amphibole with kaolinite; between gibbsite with quartz; between S0 and Md, quartz, feldspar, amphibole. There were two sediment groups: Group 1 was weakly dynamic, and Group 2 was strongly dynamic. The minerals in the sediments were mainly continental, characterised by illite, kaolinite, chlorite, quartz, feldspar, and amphibole, with other sources, including precipitation and weathering, being limited.
Bui Van Vuong, Nguyen Dac Ve, Nguyen Thi Mai Luu, Hoang Thi Chien, Tran Duc Thanh, Dang Hoai Nhon*
Development of sustained-release floating tablets of diltiazem hydrochloride
Diltiazem hydrochloride (DTZ), utilised for cardiovascular conditions, possesses a short half-life, necessitating frequent dosing. To enhance compliance, sustained-release (SR) floating tablets were developed using a quality by design (QbD) approach. This study aimed to formulate DTZ 120 mg tablets, conforming to United States Pharmacopeia 2023 dissolution standards, at a batch size of 1000 tablets. Wet granulation was employed with hydrophilic polymers to control drug release, while gas-generating excipients were used to ensure buoyancy. Tablets were evaluated for floating characteristics, in vitro dissolution, and drug release mechanisms. Hydroxypropyl methylcellulose K100M controlled release (HPMC K100M CR), NaHCO3, and PVP K30 significantly influenced output variables and were selected for the experimental design. The release rate of DTZ decreased with higher amounts of HPMC and NaHCO3, while PVP had a minimal effect. The optimised formula included HPMC K100M CR (501.5 mg), NaHCO3 (244.8 mg), PVP K30 (32.4 mg), and other excipients. Tablets exhibited a floating lag time of less than 1 minute and a floating duration exceeding 30 hours. Dissolution results met United States Pharmacopeia standards, showing values of 26.99±0.97% at 6 hours, 50.31±0.40% at 12 hours, and 91.46±1.92% at 30 hours. The manufacturing process for 1000 tablets per batch was established, and process parameters were investigated.
Hung Pham Van, Tung Nguyen Thanh, Nhat Hoang Thi Anh, Hieu Bui Trung, Uyen Dinh Thi Thu, Duyen Nguyen Thi Thanh*
Efficacy of auricular acupuncture combined with electroacupuncture for chronic low back pain: A randomised controlled trial
Chronic low back pain (CLBP) imposes significant medical treatment costs and leads to numerous serious health consequences. In recent years, non-pharmacological therapies have garnered increasing attention, particularly electroacupuncture (EA) and auricular acupuncture (AA). While considerable research has examined the efficacy of EA and AA in managing CLBP, it may be beneficial to investigate the impact of combining these approaches. This study evaluated the efficacy of a combined AA and EA treatment for CLBP compared to EA alone. This randomised, double-blind, controlled trial allocated 80 patients into two groups: one receiving EA in conjunction with AA at the target points Shenmen (TF4), Lumbosacral Vertebrae (AH9), and Subcortex (AT4), and the other receiving EA with sham AA (AA applied at non-acupoint locations). Pain intensity, functional disability, and spinal mobility were assessed using the visual analogue scale (VAS), Oswestry disability index (ODI), and Schober index at baseline (T0), after 7 days (T7), and after 14 days (T14). While both groups exhibited improvement, the intervention group demonstrated a greater reduction in VAS scores (T14: 1.65±0.66 vs. 3.28±0.91, p<0.001) and ODI scores (T14: 13.98±1.43 vs. 17.45±1.74, p<0.001), alongside a significant increase in spinal flexibility (Schober index: 14.66±0.80 vs. 13.43±1.04, p<0.001). In conclusion, among patients with CLBP, the combination of AA and EA resulted in more effective pain relief and greater improvement in spinal function compared to EA alone.
Son Thi Nguyen, Minh Quan Hoang Le*, Ngoc Nghia Thi Nguyen, Thuong Hoai Nguyen, Thuc Anh Ho
Investigating Palmatine’s inhibitory mechanism on type 2 diabetes via molecular docking
Type 2 diabetes mellitus (T2DM) is the most common form, accounting for more than 90% of all individuals with diabetes worldwide. Currently, T2DM is on the rise and is increasingly affecting younger individuals, becoming a serious public health issue. Palmatine is a natural isoquinoline alkaloid belonging to the protoberberine group. The purpose of this study was to evaluate the anti-diabetic properties of Palmatine through molecular docking with several protein targets related to T2DM, such as α-amylase, pyruvate dehydrogenase kinase 4 (PDK4), α-glucosidase, protein tyrosine phosphatase 1B (PTP1B), aldose reductase (AKR1B1), and 11β-hydroxysteroid dehydrogenase (11β-HSD1). Lipinski’s rule of five was employed to assess the drug-like characteristics of Palmatine. The pharmacokinetic properties of Palmatine were evaluated using the pkCSM tool, which aids in predicting its absorption, distribution, metabolism, excretion, and toxicity (ADMET) profile. The oral bioavailability of Palmatine was assessed using the SwissADME tool. The results indicated that Palmatine inhibits 11β-HSD1 with the lowest binding energy (-8.4 kcal/mol). According to Lipinski’s analysis, Palmatine exhibits properties consistent with druglike behaviour. The predicted pharmacokinetic parameters suggest that this compound possesses excellent intestinal absorption. Furthermore, Palmatine demonstrated favourable oral bioavailability. Consequently, additional in vitro and in vivo research is necessary to further explore the potential of this compound as a future treatment for diabetes.
Study on the causal relationship and optimise the extraction procedure of herbal preparation from Herba Mimosae pudicae, Folium Erythrinae variegatae, Cortex Cinnamomi iners, and Herba et radix Scopariae
Herbal preparations from four herbs - Mimosa pudica, Erythrina variegata, Scoparia dulcis, and Cinnamomum iners - exhibit sedative effects, treat insomnia, and effectively reduce anxiety and depression. The chemical components present in these medicinal herbs, such as mimosine and coixol, are biologically active substances. This study investigates the causal relationship and optimises the extraction procedure to achieve higher extraction efficiency. Fourteen experiments were designed using Design-Expert software to evaluate the influence of three independent variables (number of extractions, extraction time, and solvent-to-material ratio) on four dependent variables (extraction efficiency of mimosine, extraction efficiency of coixol, total extraction efficiency, and production cost). The content of mimosine and coixol was determined using the high-performance liquid chromatography (HPLC) method. Data were utilised as input for Phasolpro RD 1.0 software to model and optimise the extraction procedure for the medicinal herbs in the formulation. The extraction process was optimised with a solvent-to-material ratio of 21:1, two extractions, and an extraction time of 2.03 hours. The optimised procedure provides a useful foundation for improving extract quality and applying it as a semi-finished material for medicinal product production.
Effect of dilution ratio, storage time and storage temperature on goat sperm quality
Artificial insemination is a technique that facilitates the rapid development of livestock herds, including goats, improves breeds, and produces healthy, high-yield livestock. The liquid storage of semen is an effective method for short-term preservation to support artificial insemination. The Mekong delta offers natural conditions favourable for goat farming. This study aimed to determine the optimal temperature, dilution ratio, and storage duration for preserving goat sperm in Tris-Citrate-Glucose (TCG) medium. The experiment comprised six treatments, each repeated eight times. After collection, semen samples were diluted in TCG medium at ratios of 1:25, 1:250, and 1:2500, and stored at two temperatures: 5°C and 15°C. Sperm quality was evaluated at six specific preservation intervals: 0, 6, 12, 48, and 72 hours. The results indicated that goat sperm quality was best after 72 hours of storage when diluted at a ratio of 1:25 and stored at 15°C. Specifically, after 72 hours of storage at 15°C, samples with a dilution ratio of 1:250 recorded overall motility, progressive motility, viability, and membrane integrity rates of 70.10, 44.79, 72.33, and 48.50%, respectively. In conclusion, the optimal conditions for preserving goat sperm were achieved with a dilution ratio of 1:250 at 15°C for up to 72 hours.
Tran Thi Thanh Khuong*, Nguyen Thi Bich Thuy
Isolation and identification of IAA-producing rhizobacteria from Robusta coffee plantations in Dak Nong province
This study aimed to isolate and identify indole-3-acetic acid (IAA)-producing microorganisms from the rhizosphere of Robusta coffee plantations in Dak Nong province, Vietnam. A total of 539 microbial strains (319 bacteria, 140 fungi, and 80 actinomycetes) were isolated and screened for IAA production using the Salkowski colourimetric method. Key findings revealed that 32.0% of bacterial isolates and 33.6% of fungal isolates demonstrated IAA production above 1.0 μg/ml, with 9 bacterial strains and 4 fungal strains producing more than 50.0 μg/ml of IAA. In contrast, only 3.8% of actinomycetes showed minimal activity (1.0-10.0 μg/ml). Key findings of this study are the identification of strain DN13_B03, which exhibited the highest IAA production (178 μg/ml), confirmed by Highperformance liquid chromatography (HPLC) analysis with a distinct peak matching the standard IAA sample. Based on morphological characteristics (yellowish-white colonies, Gram-positive rod-shaped cells) and 16S rRNA gene sequencing, we identified DN13_B03 as Priestia megaterium. Optimisation studies revealed that maximum IAA production (205 μg/ml) was achieved with 0.5% L-tryptophan, at pH 6.0, within a broad temperature range (25-40°C). The remarkable IAA-producing capability of this indigenous strain presents significant potential for developing region-specific biofertilisers to enhance sustainable coffee cultivation in Vietnam.
Nguyen Duy Phuong*, Nguyen Thi Thu Ha, Nguyen Thanh Duc, Nguyen Le Thanh An, Nguyen Thanh Ha
A new dichloro-substituted benzyl alcohol derivative from the rhizomes of Curculigo capitulata (Lour.) Kuntze
Curculigo capitulata (Lour.) Kuntze’s rhizomes have been utilised in traditional medicine for the treatment of various diseases, such as kidney stones, high blood pressure, nephritis, and cystitis. To date, there has been limited research on its chemical constituents in Vietnam. A phytochemical investigation of the ethyl acetate extract from C. capitulata’s rhizomes led to the isolation of five compounds, including a novel dichlorophenolic derivative, named capitulatol A (1), and four known compounds: O-orsellinaldehyde (2), cinnamic acid (3), orcinol (4), and orcinol glucoside (5). Their structures were elucidated using 1D and 2D nuclear magnetic resonance (NMR) spectroscopic and high-resolution electrospray ionisation-mass spectrometry (HRESI-MS) data, along with comparisons to previously published references. Compound 1 has not been described before, while compounds (2-4) have been isolated from this plant for the first time. These results indicate that phenolics and phenolic glucosides are the main components, which can serve as significant markers for the chemotaxonomy of the herb. Moreover, this chemical information will enhance our understanding of this plant, both in Vietnam and globally. Furthermore, the findings can be applied to further research in pharmacology and clinical medicine in the future.
Viet Hau Dang*, Thi Trang Phan, Thi Hue Nguyen, Thi Thu Trang Nguyen, Thi May Nguyen, Thi Loan Le, Thi Hong Anh Nguyen, Minh Khoi Nguyen, Van Tai Nguyen
Energy efficiency evaluation of a centralised wastewater treatment plant in an industrial zone of former Binh Duong province, Vietnam
Efficient energy utilisation in wastewater treatment plants is a significant challenge for management, particularly in developing countries. This study presents an integrated approach combining energy auditing, real-time monitoring, and energy assessment to optimise industrial wastewater treatment plant operations in Vietnam, with a treatment capacity of under 4,000 m³/day. The research methodology employs an energy audit approach combined with daily measurements, analysing the plant’s operational data for 2023. Results indicate that the aerobic tank consumes the most energy (56.1% of total plant consumption). Wastewater pumps, blowers, mixers, and sludge pumps consume a substantial amount of electricity (77.6% of total electricity consumption). The average specific energy consumption is 0.93 kWh/m³ of treated wastewater, 10.58 kWh/kg CODremoved, and 59.12 kWh/kg TNremoved, which are 15-20% higher than international benchmarks for similar-scale facilities. Based on the analysis, we propose optimisation strategies: (1) improving operating conditions and flexibility; (2) optimising the blower system for aerobic tanks; (3) upgrading to energy-efficient pumps; (4) enhancing lighting, automatic monitoring, and office systems; (5) integrating renewable energy sources. These interventions could reduce energy consumption by 25-30% while maintaining treatment efficiency. The research findings will enhance the plant’s energy efficiency, reduce operational costs, and support Vietnam’s goal of achieving net-zero emissions by 2050.
Structural distortion and temperature-dependent carrier transport of Al-, Ga-, and In-doped ZnO thin films
ZnO-based films hold significant potential for optoelectronic applications, such as transparent electrodes and absorbance layers, as well as thermoelectric applications. Doping with Al, Ga, and In has attracted considerable attention for controlling the carrier transport properties of these films. Pure ZnO, Al-doped ZnO, Ga-doped ZnO, and In-doped ZnO films, each with a similar doping ratio of 1 wt%, were successfully deposited on glass substrates using the magnetron sputtering technique. X-ray diffraction was employed to confirm the ZnO structure, while temperature-dependent Hall-effect measurements were utilised to investigate the dependence of carrier transport on temperature. The results indicate that Al and Ga dopants enhance conductivity more effectively than In. This may be attributed to a substantial increase in carrier concentration when Al and Ga are doped into ZnO-based films as the temperature rises. Conversely, the In-doped ZnO film exhibits an increase in mobility, resulting in enhanced conductivity. These findings underscore the intricate interplay between doping elements, measurement temperature, and the electrical behaviour in ZnO films, offering valuable insights for further optimisation and application in various electronic and optoelectronic devices. This research opens the possibility of controlling the properties of ZnO films for applications at different operating temperatures.
Trang Thuy Thi Phan, Oanh Kieu Truong Le, Quang Thua Trieu, Vinh Cao Tran, Thang Bach Phan, Anh Tuan Thanh Pham
Trang Thuy Thi Phan, Oanh Kieu Truong Le, Hoa Thi Lai, Quang Thua Trieu, Thu Bao Nguyen Le, Vinh Cao Tran, Thang Bach Phan, Anh Tuan Thanh Pham
Hydrogen spillover on Ni-, Pd- and Pt-doped ZnO ultra-thin films: A density functional theory study
Hydrogen spillover plays an important role in heterogeneous catalytic reactions, such as syngas production, hydrogen production, and CO2 conversion. Among metal oxide materials, ZnO films stand out as promising candidates for hydrogen storage, though their pure form has limitations for certain applications. In this study, the hydrogen spillover on Ni, Pd, and Pt-doped ZnO ultra-thin films is investigated by employing the DFT+U method. To this end, the spillover and non-spillover structures of hydrogen are considered, and their electronic structures are evaluated in undoped and doped ZnO ultra-thin films. The calculated results show that the Ni, Pd, and Pt-doped ZnO ultrathin films can alter the electronic properties of the undoped material from insulating to metallic characteristics. While hydrogen spillover cannot occur on undoped ZnO films, it can proceed with 50% coverage of H atoms on Pd-doped ZnO films and 100% hydrogen coverage on Ni- and Pt-doped ZnO films. This study paves the way for synthesising ZnO-based catalysts for hydrogen storage, catalysis, and other desired applications.