Asia-Pacific Journal of Science and Technology

Characterization of extracellular protease-producing bacteria isolated from the coastal environment of Bangladesh and optimization of parameters for enzyme production

Mon, 03 Nov 2025 00:00:00 +0700

Bangladesh's coastal soil and water harbor a diverse array of native microorganisms that can serve as a significant source of natural protease enzymes, with broad applications in biotechnology, food industries, and environmental sectors. The objective of this study was to isolate and identify native protease-producing bacteria from Cox's Bazar, a coastal region of Bangladesh, and to optimize the parameters for enzyme production. The bacteria found in the soil and water samples were initially assessed using the zone of inhibition technique and hemolytic test. Five of the isolated bacteria exhibited proteolytic activity and were found to be non-pathogenic. The isolates were subsequently identified through morphological, biochemical, molecular, and evolutionary analysis. Among the identified isolates (Bacillus subtilis, Xenorhabdus nematophilia, and Enterobacter cloacae), B. subtilis was determined to be the most productive bacterial species. A temperature of 35°C, pH 7, 36 h of incubation, and galactose as the carbon source, were the best conditions for protease production. The enzyme activity of B. subtilis was found to be 0.37 U/mL, compared to 0.56 U/mL for a commercial enzyme. These findings suggest that B. subtilis obtained from the coastal water of Bangladesh has the potential to serve as a local source for protease production, with applications in food processing, animal feed, dairy, meat, textiles, waste management, and pharmaceutical industries in Bangladesh.

Acute effects of Gua Sha on thoracolumbar fascia thickness and related physiological parameters in healthy young people: A randomized controlled trial

Beibei Wang, Yang Hu , Hongxiu Chen, Dehui Lai, Wichai Eungpinichpong — Mon, 03 Nov 2025 00:00:00 +0700

This study explores the potential mechanism of single Gua Sha therapy on thoracolumbar fascia thickness and related physiological parameters in 66 healthy individuals randomly assigned to a 15-min Gua Sha group or a 15-min rest control group. Thoracolumbar fascia thickness, pressure pain threshold, tissue hardness, skin temperature, lumbar spine flexibility, stress index, and heart rate variability were assessed before and immediately after the interventions. The results revealed a significant reduction in thoracolumbar fascia thickness in the Gua Sha group (Left side: a reduction of 0.06 mm, p<0.05, effect size 0.14; Right side: a reduction of 0.09 mm, p<0.05, effect size 0.22). Skin temperature also increased significantly (mean difference: 0.64 °C, 95% CI: 0.57–0.71, p<0.001), and thoracolumbar fascia improved (mean difference: 0.75, 95% CI: 0.27–1.22, p<0.01), suggesting a softening effect of Gua Sha on the fascia. However, contrary to the hypothesis, the Gua Sha group showed a decreased pressure pain threshold and increased tissue hardness. Both interventions effectively reduced the stress index and enhanced heart rate variability, although there were no significant differences between the groups (p＞0.05). In conclusion, this study found that a single session of Gua Sha therapy could induce a subtle but significant reduction in thoracolumbar fascia thickness and improve specific physiological parameters in healthy individuals, but the unexpected findings regarding the pressure pain threshold and tissue hardness require further investigation to elucidate the underlying mechanisms, offering insight into Gua Sha’s possible mechanisms.

In vitro anti-leukemic activity of Terminalia arjuna bark extract loaded chitosan nanoparticles on HL-60 cell lines

Mon, 03 Nov 2025 00:00:00 +0700

The bark of Terminalia arjuna (Roxb. ex DC.) Wight & Arn. has been traditionally used in Indian medicine for treating various ailments, including leukemia. Chitosan, a natural biopolymer, serves as a promising carrier for targeted drug delivery. This study focuses on the encapsulation of hexane-ethanolic bark extract (HEB) of T. arjuna using chitosan nanoparticles (CSNPs) and evaluates their anti-leukemic potential against HL-60 cell lines. The HEB-loaded CSNPs (HEB-CSNPs) were synthesized and their entrapment efficiency, drug release profile and cytotoxic activity were assessed. In vitro release studies demonstrated a controlled and sustained drug release of 96.66% within three hours. Drug release kinetics followed the Higuchi model with a correlation coefficient (R²) of 0.98, indicating diffusion-controlled release. Fourier transform infrared (FTIR) spectra confirmed the presence of characteristic functional groups of both chitosan and the plant extract. X-ray diffractometer (XRD) analysis revealed an increase in nanoparticle size from 56.88 nm (control) to 64.53 nm upon encapsulation. Search engine marketing (SEM) imaging showed well-dispersed nanoparticles with a large surface area. Cytotoxicity analysis on HL-60 cells demonstrated dose-dependent activity, with an inhibitory concentration (IC) IC50 value of 185.2 μg/mL for HEB-CSNPs. Conclusion: Overall, this study demonstrates that CSNPs are effective carriers for T. arjuna bark extract, ensuring efficient encapsulation, sustained release, and significant anti-leukemic activity in vitro. These findings suggest the potential of HEB-CSNPs as a biocompatible and eco-friendly nanomedicine for leukemia treatment and warrant further investigation in preclinical models.

Design and analysis of novel organic thin film multiplexer

Arun Pratap S. Rathod, Pawan K. Mishra — Mon, 03 Nov 2025 00:00:00 +0700

In recent years a transition from conventional electronic devices based on silicon to organic material based electronic devices has been observed. As the market for flexible and wearable devices has presented greater opportunities and sharp growth, the demand for organic thin film transistor (OTFT) based combinational circuits has increased exponentially. Traditionally such circuits were fabricated through complementary metal oxide semiconductor (CMOS) logic architecture, but due to large number of nodes OTFTs employed in circuit implementation, the overall power consumption, interconnect delay and the chip area of the circuit increases significantly. Organic thin film multiplexer (OTFM) is a novel attempt to redesign an existing multi-transistor combinational logic device like 2:1 Multiplexer in the form of a single multi-layered logical device, while maintaining the dimensions, material composition and fabrication method equivalent to single OTFT (bottom gate bottom contact OTFT). The design and development of the OTFM has been achieved through Silvaco a large ion collider experiment (ATLAS) technology computer-aided design (TCAD) tool while the examination of power and area consumption of the OTFM and equivalent CMOS circuit was accomplished through post layout (physical design) analysis using Cadence Virtuoso exploratory data analysis (EDA) tool. It has been found in this research that the power and chip area consumption of proposed OTFM is lower than that of CMOS logic based 2:1 Multiplexer by 90% and 95% (approx.) respectively, while operating under same voltage regime for implementing identical logical functions.

Green synthesis of ZSM-5 using biomass fly ash and recycled mother liqour

Patthra Pengthamkeerati, Phatchariya Welutung — Mon, 03 Nov 2025 00:00:00 +0700

The effects of synthesis conditions, silica derived from biomass fly ash, and mother liquor recycling on the synthesis of ZSM-5 were investigated using both hydrothermal and clear solution methods. The synthesis of ZSM-5 from TEOS was optimized using a hydrothermal autoclave reactor and reflux assisted by microwave treatment, revealing that the combined reflux–microwave approach significantly enhances crystallization, resulting in high-quality ZSM-5. In contrast, reduced synthesis time and milder conditions (e.g., lower pressure) proved ineffective, highlighting the need for more rigorous conditions to promote zeolite formation. For biomass fly ash-derived silica, two distinct molar ratios were tested, demonstrating that the ratio 25Si:1Al:9TPAOH:0. 16NaOH:495H2O:100EtOH was more effective than 1Al₂O₃:40SiO₂:0.2TPAOH, which produced a mixture of silicalite-1 and amorphous phases. Recycling the mother liquor from ZSM-5 synthesis yielded comparable product quantities and preserved well-defined crystallinity, although excess sodium ions reduced yields. Scanning electron microscopy showed that recycling resulted in smaller, well-dispersed crystals, suggesting enhanced nucleation and crystal growth. Overall, this study highlights the critical role of synthesis conditions and precursor selection in the efficient, resource-conscious production of ZSM-5 from biomass waste.

P2O5/SiO2-Catalyzed solvent-free room-temperature synthesis of 2-aryl-benzimidazoles and their toxicity against Artemia salina

Janus B Pansacala, Joshua Andrew P Nillama, Evelyn C Creencia — Mon, 03 Nov 2025 00:00:00 +0700

Twelve (12) 2-Aryl-1H-benzimidazole derivatives were synthesized from a series of 4-o-phenylenediamines [R: -NO₂, -COOCH₂CH₃, and -COAr] and 4-aryl aldehydes [R: -H, -N(CH₂CH₃)₂, -CH(CH₃)₂, -CH(OCH₂CH₃)₂] utilizing a simple, cheap, and heterogeneous P₂O₅/SiO₂ catalytic system at room temperature and solvent-free conditions. Moreover, the bioactivity of the prepared benzimidazoles, evaluated via brine shrimp lethality assay (BSLA), showed that almost all benzimidazole products were cytotoxic, except for 5-nitro-2-phenyl-1H-benzo[d]imidazole (5a). Highest activity was observed for 2-(4-isoproylphenyl)-5-nitro-1H-benzo[d]imidazole (5b) with acute lethal concentration (LC₅₀) of 43.42 ppm, whereas the least active N, N-diethyl-4-(5-nitro-1H-benzo[d]imidazol-2-yl) aniline (5c), had chronic LC₅₀ value of 283.39 ppm. Qualitative structure - BSLA activity correlation showed that balanced electron-donating capacity of R₂ coupled with electron-withdrawing effect of R₁ led to enhanced toxicity of 2-Aryl-1H-benzimidazoles.

A pilot study on the effects of the 6-week recreational activities program on physical fitness of elderly people in Maeka subdistrict, Phayao province

Kritsada Tampradit, Pattawan Lapo, Apiruck Wonghempoom, Prachya Wangtrakul — Tue, 04 Nov 2025 00:00:00 +0700

The purpose of this study was to investigate the effect of 6 -week recreational activities program on elderly people physical fitness and to compare their physical fitness with standard physical fitness testing criteria before and after participating in the 6-week recreational activities program, The recreational activity program was conducted 3 days per week for 60 min per day. The participants were 20 healthy older women, who volunteered to participate in this study by using the purposive sampling method. The participants were divided into 2 groups (60-64 years old group and 65-69 years old group). The health-related physical fitness of people age between 60-69 years old test developed by Department of Physical Education was used as protocols in this study. Descriptive statistics (mean and standard deviation) and a paired-sample t-test were used to analyze the data at the significance level of 0.05. The results showed that the physical fitness testing scores of participants increased significantly after engaging in the program, with a statistically significant at the .05 level before and after the program. Therefore, it was concluded that the 6-week recreational activities program could improve health-related physical fitness in elderly people.

Music versus midazolam to alleviate anxiety and physiological responses in patients receiving spinal anesthesia: A prospective randomized controlled study

Tue, 04 Nov 2025 00:00:00 +0700

This study aimed to evaluate the anxiety levels and physiological responses between music listening and given intravenous midazolam for perioperative anxiolytics in patients who receiving spinal anesthesia (SA). This prospective, randomized, controlled trial was conducted in adult patients undergoing elective surgery under SA. Participants were randomly assigned to either the music group (Mu group) or the midazolam group (Mi group). The Mu group listened to their preferred music, while the Mi group received an intravenous midazolam. Anxiety levels were assessed using State-Trait Anxiety Inventory (STAI) questionnaire, and physiological parameters were recorded pre- and postoperatively. The primary outcome was the change in STAI score from pre- to postoperative assessment. Secondary outcomes included the changes of physiological parameters, incidence of complications, and patient satisfaction. A total of 72 patients completed the study, 38 patients in Mu group and 34 patients in Mi group. The mean change in STAI score was -2.9 (SD 8.0) in the Mu group and -5.7 (SD 6.6) in the Mi group, with a mean difference of 2.78 (95% CI -0.7 to 6.3, p = 0.114). There were no significant differences in physiological parameters or complication rate between groups. Patient’s satisfaction scores were high in both groups. These finding suggest that music may be a viable alternative to midazolam for intraoperative anxiolysis in patients undergoing SA.

High methane production by Methanobacterium ferruginis Mic6c05T, a hydrogenotrophic methanogen isolated from a depleted oil and gas field in a neighboring country.

Nusara Yinyom, Kusuma Rintachai, Siriwan Wichai — Tue, 04 Nov 2025 00:00:00 +0700

Some depleted oil and gas fields harbor anaerobic microbes, including methanogens. In this study, methanogens were isolated from a depleted oil and gas field in a neighboring country using enrichment techniques in methanogenic media (ATCC 1340). Five isolates were obtained. Among them, three isolates- ATCC 06.2-1, ATCC 06.2-2, and ATCC reactor 1- demonstrated a strong ability to produce high levels of methane in the ATCC 1340 medium. This culture medium is specifically designed to convert H₂ and CO₂ at a ratio of 4:1, leading to a theoretical total yield of 249.82 µmol of methane. The results indicated that ATCC 06.2-1, ATCC 06.2-2, and ATCC reactor 1 achieved methane production percentages of 94.07%, 75.65%, and 72.05% of the theoretical yield, respectively. Additionally, all three isolates could utilize formate and methanol as substrates for methane production and were classified as hydrogenotrophs. Genetic identification revealed that the three methane-producing isolates- ATCC 06.2-1, ATCC 06.2-2, and ATCC reactor 1- belong to the species Methanobacterium ferruginis Mic6c05^T. The other two isolates, ATCC 03 and ATCC 04.2, were identified as Clostridium sporogenes DSM 795^T. The three methane-producing isolates and the two Clostridium isolates show significant potential for optimizing alternative energy sources.

Silicon source from calcium silicate of steel making slag on leaf thickness, trichomes number, yield and silicon content in rice RD 49 variety grown under nutrient solution by deep water technique system

Araya Srisuwan, Aunthicha Phommuangkhuk, Suphachai Amkha — Tue, 04 Nov 2025 00:00:00 +0700

Silicon (Si) is a beneficial element for plant growth, even though it is not considered an essential nutrient. Si plays a crucial role in strengthening plant structures, improving resistance to pests and diseases, and enhancing stress tolerance. The present study investigates the effects of calcium silicate from steel-making slag as a Si source on the plant growth, leaf thickness, number of trichomes, yield, and silicon content of rice (RD 49 variety) grown in a nutrient solution by the deep water technique. The experiment was conducted with a completely randomized design (CRD) with ten replications and nine treatments using nutrient solutions of 0.0, 0.1, 0.5, 1, 5, 10, 50, 100, and 500 mg CaSiO₃/L. The results indicate that CaSiO₃ concentrations of 10, 50 and 100 mg/L could promote rice growth and yield of rice. CaSiO₃ concentrations of 50 and 100 mg/L effectively increased the cutin layer thickness. Additionally, the 100 and 500 mg/L CaSiO₃ concentrations in the nutrient solution by the deep water technique were found to enhance the Si content in leaves, stem, and husk in rice. These findings suggest that CaSiO₃ at concentrations of 50 and 100 mg/L can better promote a good yield and increased leaf thickness of rice (RD 49 variety) grown in a nutrient solution using the deep water technique.

An Intelligent IoT based anomaly detection using predictive analytics

Tue, 04 Nov 2025 00:00:00 +0700

In this study, we analyze the effectiveness of combining various machine learning approaches in order to detect specific attack classes within the Internet of Things (IoT). Using the IoT23 dataset, the research examines distinct features associated with attack classes derived from the raw data. Multiple algorithms, such as Multi-layer Perceptron, Random Forest, Extreme Gradient Boosting (XGBoost), Decision Tree, K-Nearest Neighbor, Support Vector Machine, Logistic Regression, and Naive Bayes, were thoroughly trained and evaluated. Through the implementation of ensemble learning techniques, the study successfully achieved an elevated detection rate of attack classes and an overall accuracy improvement, maintaining a false alarm rate of up to 15%. The research highlights the importance of using ensemble learning methods to identify and categorize attacks in IoT domains, serving as a valuable resource for further research. The insights revealed in this study provide readers with a compelling reason to read it and should act as a catalyst for further research in similar directions.

Green approach for selective Cu(II) recovery from aqueous solutions: Efficient separation from Ni(II) and Co(II) with organic phase regeneration

Tue, 04 Nov 2025 00:00:00 +0700

The objective of this study was to achieve the selective recovery of Cu(II) from aqueous solutions in the presence of Ni(II) and Co(II) by utilising a green approach, palm kernel fatty acid distillate (PKFAD) as the organic phase. PKFAD was employed without the use of diluent, extractant, or modifier typically required in conventional solvent extraction processes. In the first stage of the procedure, Cu(II) was selectively extracted and stripped from the multi-element solution. In the second stage, Ni(II) and Co(II) were subsequently recovered. The selectivity of the extraction process was driven by the difference in pH-dependence equilibrium (pH_eq) for each metal ion. A high Cu(II) efficiency of 97% was achieved in the first stage at pH_eq of 4.8, while Ni(II) and Co(II) extraction efficiencies of 88% and 85%, respectively, were obtained in the subsequent extraction stage at a pH_eq of 5.9. Separation factor for Cu(II) over Ni(II) and Co(II) were ≥ 180, indicating effective selective separation. Additionally, the PKFAD was successfully regenerated, with the stripping process achieved 98% of Cu(II), 85% of Ni(II) and 72% of Co(II) recovery. These results highlight the efficacy of PKFAD as a sustainable, regenerable organic phase with high potential for selective metal ion recovery.

Toward improved spawn quality: Optimizing corn grain preparation for Volvariella volvacea

Wed, 05 Nov 2025 00:00:00 +0700

Volvariella volvacea is a commercially important mushroom in tropical agriculture, yet its cultivation efficiency is often limited by inconsistent grain spawn quality. Factors such as unsuitable soaking duration and suboptimal supplementation with calcium carbonate (CaCO₃) can hinder mycelial colonization, thereby reducing yield and productivity. Therefore, optimizing grain spawn preparation is essential to enhance the growth performance and productivity of this mushroom. This study investigates the effects of soaking duration and calcium carbonate (CaCO₃) concentration on the mycelial growth of V. volvacea grain spawn. Corn grains were soaked in boiling distilled water for 1 to 5 min, with soaking in room-temperature distilled water for 6 hours used as the control. Grains soaked for 3 to 5 min showed significantly improved mycelial extension (ranging from 2.171 to 2.343 cm) and reduced colonization duration (6 days), with visibly denser mycelial growth, as assessed through qualitative observation. These optimal soaking durations were then used to assess the effect of different concentrations of CaCO₃ (1, 3, and 5% w/w). Grains treated with 3% CaCO₃ exhibited highly favorable mycelial density. Thus, these findings recommend a 5-min soaking duration combined with 3% CaCO₃ for optimal grain spawn preparation, facilitating rapid and dense mycelial growth. This optimized method provides a practical framework for enhancing colonization speed and improving spawn quality in V. volvacea, thereby increasing the efficiency and reliability of corn grain spawn preparation.

Investigation of the metallurgical microstructure resulting from underwater welding at depths of 3 and 5 meters using UW-1 and E6013 welding electrodes.

Wed, 05 Nov 2025 00:00:00 +0700

This study presents a comparative analysis of underwater welding using E6013 and UW-1 electrodes on carbon steel at depths of three and five meters. The investigation focuses on weld quality, microstructure, and hydrogen content. At a depth of three meters, both electrodes produced welds that met standard criteria and were free of porosity, slag inclusion, and cracking. UW-1 produced smoother and more completely fused surfaces, aided by the forehand welding technique and proper electrode angle, which promoted stable metal transfer and clear visibility of the molten pool. scanning electron microscope (SEM) analysis revealed alternating martensite and pearlite in the weld zone (WZ), with E6013 producing more martensite and a coarser structure in the heat-affected zone (HAZ), along with visible separation from the base metal. Energy Dispersive X-ray Spectroscopy technology (EDS) analysis showed hydrogen content in the WZ was 11.02% for E6013 and 6.50% for UW-1, the latter being lower than typical underwater welding levels (7.0–11.7%). In the HAZ, E6013 and UW-1 showed 5.23% and 5.06% hydrogen, respectively. The results suggest that E6013 can serve as a temporary substitute for UW-1 in shallow underwater welding, but its use should be limited to depths not exceeding three meters due to quality control constraints at greater depths.

Fuzzy logic enhanced machine learning framework for adaptive thermal absorber configuration optimization in building integrated photovoltaic thermal systems

Dinesh Kumar Nishad, Rashmi Singh, Saifullah Khalid, Raj Sinha — Wed, 05 Nov 2025 00:00:00 +0700

Building integrated photovoltaic thermal (BIPVT) systems represent a promising technology for achieving net-zero energy buildings by simultaneously generating electricity and thermal energy. However, optimizing thermal absorber configurations remains challenging due to complex interactions between environmental variables, system parameters, and performance objectives. This paper presents a novel fuzzy logic-enhanced machine learning framework for adaptive thermal absorber configuration optimization in BIPVT systems. The proposed framework integrates fuzzy inference systems with advanced machine learning algorithms to dynamically optimize absorber tube geometries, material properties, and operational parameters. The methodology incorporates real-time environmental data, system performance metrics, and user preferences to provide intelligent decision-making capabilities. Experimental validation demonstrates that the proposed framework achieves 15.3% improvement in thermal efficiency and 12.7% enhancement in overall system performance compared to conventional optimization approaches. The fuzzy logic component enables interpretable decision-making while maintaining robustness under uncertain operating conditions. Results indicate that spiral absorber configurations optimized through the proposed framework achieve the highest performance with 36.4% overall efficiency at 1000 W/m² solar irradiance.

Seed priming with spent tea leaves (Camellia sinensis L.) promotes early growth of black cherry tomato (Solanum lycopersicum L. var. cerasiforme) seedlings under drought stress

Luong Thi Le Tho, Luong Thi Thu Ngan, Luu Tang Phuc Khang — Wed, 05 Nov 2025 00:00:00 +0700

Black cherry tomato (Solanum lycopersicum L. var. cerasiforme) is an economically important crop valuable crop but is highly sensitive to drought, which hampers seed germination and early seedling growth. While spent tea leaves (STL) are known for their biological activity, their effects on tomato germination under drought stress remain unclear. This study evaluated STL extracts from black, green, and oolong cultivars as seed priming agents to enhance germination and early growth of black cherry tomato under polyethylene glycol (PEG-6000)-induced drought stress. Tomato seeds were surface-sterilized and then soaked in STL extracts at concentrations of 1%, 2%, or 4% (w/v) for 24 hours at 25^oC before sowing. Increasing PEG-6000 concentrations (0%, 4%, 8%, and 12%) caused significant reductions in germination percentage, shoot length, root length, seedling vigor index and fresh biomass, with the most severe declines observed at 12% PEG-6000. Priming with STL extracts mitigated these adverse effects in a tea type- and concentration-dependent manner. Black and oolong tea extracts at 2–4% improved germination percentage, germination speed, and vigor indices, while also enhancing radicle and plumule length, shoot height, and biomass under stress. In contrast, green tea exerted weaker or inhibitory effects. These findings suggest that black tea extract at 4% offers an effective and low-cost strategy approach to improve drought tolerance in black cherry tomato, promoting sustainable agricultural practices in the face of environmental stress.

Zinc (II) metal appended Artificial Nucleases as Anticancer Agents: A Brief Review

Anupriya Adhikari, K Ganesh Kadiyala, Mamta Bisht, Neetu Sharma, Bhawana Bisht — Mon, 03 Nov 2025 00:00:00 +0700

Zinc (II) complexes have recently gained attention for their unique ability to mimic natural nucleases and selectively target deoxyribonucleic acid (DNA), making them attractive candidates in the search for more effective and less toxic anticancer agents. This review explores the evolving landscape of Zn (II)-based artificial nucleases, focusing on how structural modifications—such as macrocyclic scaffolds, aromatic appendages, and bio-relevant ligands—enhance their ability to bind and cleave DNA. These complexes operate through both hydrolytic and oxidative pathways, disrupting genetic material and triggering programmed cell death in cancer cells. Their redox stability, biocompatibility, and catalytic efficiency offer distinct advantages over other metal-based systems. By bridging the fields of inorganic chemistry and oncology, these zinc complexes show great potential not only as therapeutic agents but also as molecular tools in gene editing and biomedical research. This review brings together recent findings to provide a clearer understanding of how Zn (II) based systems function and where their future applications might lie.