Hue University Journal of Science: Natural Science

Compatibility and optimization of antigen content to develop combined acellular diphtheria-tetanus-pertussis (DTaP) vaccine at Institute of Vaccines and Medical Biologicals

2025-05-15T07:52:51+00:00

Compatibility between components and the amount of antigens in combination vaccines are important factors determining the safety, efficacy, and stability of that vaccine. To develop the diphtheria-tetanus-acellular pertussis (DTaP) vaccine at the Institute of Vaccines and Medical Biologicals (IVAC), we evaluated the compatibility among the components and optimized the amount of antigens in the vaccine formulation. The antigen components, including tetanus antigen (T), diphtheria antigen (D), and recombinant pertussis toxoid (rPT), together with filamentous haemagglutination factor (FHA), and aluminum hydroxide adjuvant, were evaluated for compatibility by using physicochemical and immunological methods. Design Expert version 12 software was used to optimize the amount of each antigen in the DTaP vaccine formulation. The results show that the components are compatible with each other. The optimal DTaP vaccine formula contains 40 Lf/mL D, 20 Lf/mL T, 10 µg/mL rPT, 20 µg/mL FHA, and 0.6 mg Al³⁺/mL respectively, corresponding to the diphtheria potency of 94,47 IU/mL, tetanus potency of 107,86 IU/mL, and pertussis potency of 9,65 IU/mL. The DTaP vaccine developed by IVAC meets the standard of the Vietnamese Pharmacopoeia V, 2018, of the Ministry of Health, and WHO.

Impact of the Chuom model on aquatic resources and water environment in Cau Hai Lagoon and Nay Lagoon, Hue City

2025-05-19T08:37:01+00:00

This research assesses the impact of the Chuom model on the aquatic resources and water environment to serve as a basis for sustainable use of aquatic resources. This model is based on a traditional fishing mode called Chuom or Cha Rao in Vietnam and is used in both freshwater (Nay Lagoon) and brackish water (Cau Hai Lagoon). The results show that the model is effective in attracting fish species. The number of economic fish species inside the Chuom area is larger than that outside, with the Cau Hai Lagoon having nine species against five species and the Nay Lagoon having 13 species against 11 species. The model also increases the fish mass and the density of zooplankton inside the Chuom. Water quality parameters such as pH, NH₄/NH₃, and DO in the Chuom area are similar to those outside. It is necessary to have an official program to develop the Chuom model in the localities.

Hydroxyapatite production from animal bone sources

2025-03-10T03:02:22+00:00

In this study, the bone char composition of cows, buffaloes, pigs, and goats was studied. The samples were characterized by using X-ray diffraction, thermal analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The main component is hydroxylapatite (Ca₅(OH)(PO₄)₃) with the following content: 67.7% in buffalo bones, 65.2% in cow bones, 58% in pig bones, and 48% in goat bones. The bone char exhibits a nano-sized morphology ranging from fibres to granules depending on the calcination temperature and animal bone type. The bone char is suitable as a starting material for producing organic nano phosphate fertilizer.

Inhibitability of compounds from lactuca indica L. towards enzyme alpha-glucosidase based on quantum chemical calculation and docking simulation

2025-04-29T02:11:21+00:00

Abstract. Diabetes causes excessively high blood sugar levels and disrupts metabolism in the body. Inhibiting the α-glucosidase enzyme is one of the treatments for diabetes. In this study, the compounds from Lactuca indica L. in the n-hexane extract were screened in silico to identify potential inhibitors of the 3W37 protein of the α-glucosidase enzyme. Eleven compounds (1–11) from the extract were identified by using the GC-MS method. The geometric structures of these compounds were optimized, and their quantum parameters were determined with the natural bond orbital method. The binding sites 1 and 2 of the protein were identified as favourable for molecular docking, and the inhibitory potential of the compounds was ranked in descending order as follows: 3 > 8 > 10 > 5 > 7 > 6 > 11 > 4 > 1 > 9 > 2. These compounds comply with Lipinski’s Rule of Five and exhibit pharmacokinetic and toxicity properties, including good absorption, no hepatic metabolism, renal excretion, and safety for the human body. These results will guide experimental studies to develop new approaches for supporting diabetes treatment.

Biodiversity of fish species composition in coastal waters of Ha Tinh province

2025-05-15T07:50:40+00:00

The study was conducted through four surveys from May 2023 to February 2025 at eight sampling sites. A total of 206 fish species were recorded, belonging to 129 genera, 64 families, and 20 orders across two subclasses (Chondrichthyes and Actinopterygii). Among them, the order Acanthuriformes was dominant, comprising 45 species (21.84% of the total species) and 14 families (21.88% of the total families). Besides, 171 species listed in the IUCN Red List (2024) under various threat categories were identified: one species as Endangered (EN), six as Vulnerable (VU), 150 as Least Concern (LC), four as Near Threatened (NT), and ten as Data Deficient (DD). According to the Vietnam Red Data Book (2007), one species (0.49%) was classified as Critically Endangered (CR). Three species (accounting for 1.46%) are listed in the Vietnam Red Data Book (2024) under the Vulnerable (VU) category. Additionally, 24 species (11.65%) were identified as having economic value, and 25 species (12.14%) are commonly cultured for commercial purposes. These findings provide important baseline data for the sustainable management and conservation of fish resources in the region.

Determination of Hg(II) with square-wave anodic stripping voltammetry method on AuNPS/ErGO-GCE electrode

2025-05-05T01:58:24+00:00

In this study, Hg(II) was determined on a modified AuNPs/ErGO-GCE electrode with the square-wave anodic stripping voltammetry (SqW-ASV) method. The morphology of the material modifying the electrode was characterized with EDX-mapping and HR-TEM. Additionally, several parameters of the SqW-ASV method, including pulse amplitude (ΔE), square wave frequency (f), potential change step (r), deposition potential (E_dep.), and deposition time (t_dep.), were investigated. Under optimized conditions: acetate buffer (ABS), pH = 5 and KCl 0.1 M, r from –0.2 to +0.8 V, E_dep: –0.9 V, t_dep: 240 s, DE: 30 mV and f: 30 Hz, the linear range of Hg(II) concentration was from 5.0 to 49,5 ppb, and the detection limit of Hg(II) was 1.89 ppb.

Electrochemical analysis of sildenafil citrate on electrode modified with nitrogen and sulfur-doped reduced graphene oxide

2025-04-25T06:01:52+00:00

In this study, nitrogen and sulfur-doped reduced graphene oxide (rGO(N.S)) was prepared with the hydrothermal method. The rGO(N.S) material was characterized with X-ray diffraction and Raman spectroscopy. A glassy carbon electrode was modified with the rGO(N.S) material to develop a novel electrochemical sensor for analysing sildenafil citrate (SDC). The electrochemical parameters of the differential pulse voltammetry technique such as accumulation potential, accumulation time, pulse amplitude, and potential step were investigated and optimized, showing a relatively low detection limit of SDC.

Optimisation of catalytic asymmetric intermolecular cyclopropanation of diazo acetoxy acetone and styrene with p-NITRO-Ru(II)-DIPHENYL-PHEOX complex

2025-03-18T01:50:38+00:00

The chiral cyclopropane ring is an important pharmacophore in pharmaceuticals and bioactive natural products, making libraries of these building blocks a valuable resource for drug discovery and development. Furthermore, the cyclopropyl ketone groups found in natural products have important biochemical properties, but only a-diazo acetophenone is developed as a ketone source, reported with 67% and 86% enantioselectivity yields. Therefore, this study presents a process to synthesise chiral cyclopropane of diazo acetoxy acetone and styrene catalysed by asymmetric p-nitro-Ru-¬dialkyl-pheox complex. This procedure was optimised under suitable solvent and temperature conditions and achieved high yields, excellent stereoisomer selectivity of more than 99:1, and enantioselectivity up to 95%. This is our exclusive published result, demonstrating the effectiveness of this catalyst in the reaction to produce highly stereoselective cyclopropanes. In addition, the study also has sufficient evidence on the mechanism of chiral cyclopropane formation with preferential trans product.

Extraction and enrichment of flavonoid and evaluation of antioxidant activity of Passiflora foetida extract

2025-05-19T03:13:36+00:00

Passiflora foetida L., commonly known as Lạc tiên in Vietnam, is a widely used medicinal plant in Vietnamese traditional medicine to treat diseases such as sedation, fever reduction, liver cooling, nervous breakdown, heart palpitations, and insomnia. In this study, the appropriate conditions for the extraction of P. foetida L. were determined as follows: 80% ethanol as the solvent, the solvent-to-material ratio of 10:1, the extraction temperature of 80 °C, the extraction time of 120 minutes, and the number of extractions 3 times. Activated charcoal was employed to remove chlorophyll before enriching flavonoids in the extract with Diaion HP20 resin. The enrichment process utilised 10% ethanol as the loading solvent with an extract-to-resin ratio of 16:30 (w/w). The elution with 70% ethanol increased the flavonoid content in the extract to 13.89%. Furthermore, the enriched extract exhibited strong antioxidant activity, with an IC₅₀ value of 34.25 µg/mL.

CeO2-Pr2O3 rare earth oxide nano materials for application as bioproduct in Angelica sinensis cultivation

2025-04-03T08:14:18+00:00

In this study, CeO₂-Pr₂O₃ nano fertilizer was manufactured and utilised as a plant growth stimulant for Angelica sinensis. CeO₂-Pr₂O₃ was synthesised from cerium(IV) nitrate and praseodymium(III) nitrate as precursors via the ultrasonic-assisted co-precipitation method. The morphology and structure of the nanomaterials were characterised by using XRD, IR, EDX, SEM, and TEM. The composite CeO₂-Pr₂O₃ substantially affected the growth and development of Angelica sinensis. After 90 days of application, the plants treated with CeO₂-Pr₂O₃ nanomaterials exhibited significantly enhanced growth performance: plant height reached 37.8 cm (an increase of 36.0%); leaf number reached 37.9 leaves/plant (an increase of 37.3%), and canopy diameter reached 49.5 cm (an increase of 31.6%) compared with the control. Additionally, Angelica sinensis plants supplemented with CeO₂-Pr₂O₃ demonstrated improved morphological characteristics, including stronger stems, thicker and greener leaves, deeper purple stem colouration, and more vigorous root systems with a greater number of lateral and main roots. These findings suggest that CeO₂-Pr₂O₃ nanomaterials possess a notable plant growth-promoting effect on Angelica sinensis.

Iridoid glycosides from Gomphandra tonkinensis Gagnep.

2025-03-13T14:34:27+00:00

Four iridoid glycosides, namely sweroside (1), loganin (2), triplostoside A (3), and gomphandranoside C (4), were isolated from the roots of Gomphandra tonkinensis Gagnep. collected in Thua Thien Hue. The chemical structures of isolated compounds were determined based on 1D-NMR and 2D-NMR spectral data and compared with previously published information. Compound 1 exhibits the ability to inhibit diabetes-related enzymes (α-amylase and α-glucosidase) with IC₅₀ values of 331.1 ± 8.6 µg/mL and 344.2 ± 6.0 µg/mL, respectively. Compound 2 has α-glucosidase inhibitory activity with an IC₅₀ value of 270.9 ± 9.7 µg/mL. Triplostoside A (3) is isolated from the genus Gomphandra for the first time.

Disposal and management of used batteries from households in Hue city: current status and proposed solutions for improvement

2025-09-30T09:05:41+00:00

Batteries, especially non-rechargeable ones, are commonly used in households. Waste batteries are classified as hazardous components in household solid waste. This paper presents the results of a survey on the current status of household battery generation and disposal and the awareness of Hue city's residents towards waste battery disposal and management and proposes some improvement solutions. The results of the survey of 109 households in 8 selected wards and communes of Hue City reveal that the battery generation rate is 0.248 kg/household/year or 0.054 kg/capita/year, corresponding to a total amount of about 30.4 tons/year or 83 kg/day for the entire Hue City. Most people are aware of the hazardous effects of used batteries and the need to separate batteries from household waste. However, over 88% of people still maintain the habit of disposing of batteries with household waste. Some barriers to proper battery disposal (sorting, storing separately, transferring to collection units) include the small amount of waste, the negligible trade value of waste batteries, and the lack of awareness of waste collectors. Several solutions to improve the disposal and management of used batteries from households have been proposed from the perspective of state management and operation of collection and treatment enterprises.

Evaluating organic matter removal efficiency in pig farm wastewater after biogas tank using a two-stage filtration system with biochar from Mimosa pigra

2025-09-30T09:17:59+00:00

This study uses biochar from Mimosa pigra plants as the filter material for a two-stage anaerobic-aerobic filtration system, aiming to evaluate the organic matter removal efficiency in pig farm wastewater after passing through a biogas tank. Two identical experimental systems, A and B, were designed, each consisting of an anaerobic filter column and an aerobic filter tank. System A operated with an organic loading rate (OLR) ranging from 71.11 to 243.75 g COD/m³/day and a hydraulic loading rate (HLR) ranging from 74.94 to 112.41 L/m²/day, while system B operated with an OLR from 103.26 to 493.01 g COD/m³/day and an HLR from 37.47 to 112.41 L/m²/day. The results show that both systems achieved a high COD (chemical oxygen demand) removal efficiency, with system B averaging 87 ± 4%, higher than system A (86 ± 3%), despite system B's higher OLR. Balancing HLR and OLR, depending on the actual conditions of the filter tank, influent loading, and treatment requirements, is crucial for optimizing the treatment efficiency and ensuring the economic viability.

Properties of concrete with coarse aggregate using steel slag mixture from Ha Tinh Formosa steel plant

2025-09-30T09:39:51+00:00

In this study, a mixture based on the emission ratio of four types of steel slag from Hung Nghiep Formosa Ha Tinh Steel Plant (Formosa steel slag) was tested with the aim of serving as coarse aggregate for cement concrete. The results indicate that, although the particles are relatively smaller than the requirements for coarse aggregates for concrete according to the TCVN 7570:2006 standard, the physico-mechanical properties of the steel slag mixture, particularly crushing value, softening coefficient, abrasion resistance, and the proportion of flat and elongated particles, all meet the requirements for coarse aggregates for concrete, even for high-grade concrete (grade over 400). The design calculation for the concrete mix was carried out, and initial specimens of concrete using Formosa steel slag as coarse aggregates were produced. The results indicate that the concrete specimens, with the usage of cement and water conforming to the Ministry of Construction’s standards, achieved compressive strength after 28 days, exceeding the requirements for grade 400 concrete by 116% to 129%. Moreover, the density of the concrete meets the requirements for ultra-heavy concrete, offering numerous technical, economic, and environmental benefits. This makes the material highly suitable for use in manufacturing wave-breaking structures to prevent coastal erosion and protect coastal infrastructure.

Effect of fabrication technique on optical properties of carbon nano-dots from gac fruit (momordica cochinchinensis spreng) skin

2025-03-03T07:56:15+00:00

In this study, we fabricated carbon dots (CDs) solutions from the skin of the Gac fruit by using the hydrothermal method. The samples were fabricated at 190 °C for 6, 8, 10, 12, 14, and 16 hours. We investigated the structural properties of the obtained CDs via X-Ray diffraction (XRD), and the optical properties of the samples were accessed via UV–Vis absorption, photoluminescence, FTIR spectra, and the quantum yield. The results show that the CDs absorb light at the wavelength of 276 nm and emit at the wavelength of 430 nm. The FTIR spectrum clarifies that the functional groups on the surface of the carbon core are hydroxyl and carbonyl. The results indicate that the quantum yield varies with the treatment time and reaches a maximal value (5,06%) at 190 °C and 14 hours.