Worananthakij, Worakrit
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Item type:Publication, Morphological and genetic characterization of marine filamentous cyanobacterium Geitlerinema isolated from Thailand(2018-04-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Antimicrobial activities and phytochemicals of Murraya paniculata L. flowers, leaves and bark crude extracts(2023-01-01); ; Taveekijakarn, PraveenaAims: Murraya paniculata (L.) has been widely employed in medicine, has also been modified to serve as an ingredient in health foods and found application in cosmetics. This study was aimed to assess the biological activities of M. paniculata by analyzing the chemical compositions of its flowers, leaves and bark. Methodology and results: Crude extracts drawn from the flowers, leaves and bark of M. paniculata underwent testing to determine the antibacterial properties in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), as well as the overall chemical composition, total phenolic content, flavonoids and antioxidant activity. Crude extract of leaves exhibited the most potent antibacterial activity when tested against Staphylococcus aureus TISTR 1466, Bacillus subtilis ATCC 6633 and Pseudomonas aeruginosa ATCC 27853. The crude extract from bark delivered the most significant antibacterial activity when tested against Micrococcus luteus TISTR 9341, Escherichia coli ATCC 1261, Pseudomonas sp., Streptococcus sp. and Methicilin resistant S. aureus (MRSA). For all crude extracts, the MIC value against M. luteus TISTR 9341 was 12.5 mg/mL. Meanwhile, the MBC value for the crude extract of leaves against B. subtilis ATCC 6633 was 12.5 mg/mL, whereas, for flower and bark crude extracts, the MBC value against S. aureus TISTR 1466 was 25 mg/mL. Antioxidant activity was at its highest for the crude extract from bark (IC50 = 1.36 mg/mL). The highest phenolic content was recorded for the crude extract from bark, while the highest flavonoid content came from the crude extract of leaves (70.81 ± 0.31 mgGAE/g extract and 115.73 ± 1.18 mgQE/g extract, respectively). Conclusion, significance and impact of study: The research findings suggest that the crude extracts of M. paniculata leaves and bark show greater significant levels of bioactivity than was the case for crude extracts from flowers. The research findings could help in exploring the possibilities of using M. paniculata for pharmaceutical purposes and in aquaculture. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microwave-assisted biosynthesis of silver nanoparticles using two marine microalgal extracts and their antimycobacteriosis activity against bacteria isolated from Betta splendens(2025-12-01); ; ; This study explores the synthesis and antibacterial properties of silver nanoparticles (AgNPs) as a safer, eco-friendly alternative to traditional chemical treatments for bacterial infections. AgNPs were synthesized using aqueous extracts of marine microalgae, Isochrysis galbana and Chaetoceros calcitrans, via conventional and microwave-assisted methods, with the latter accelerating nanoparticle production. Extracts in ethanol, hexane, and acetone were tested, with the ethanolic extract of I. galbana showing the strongest antibacterial effects. The AgNPs exhibited broad-spectrum antibacterial activity against pathogens such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and fish pathogens like Aeromonas veronii. Microwave-assisted synthesis with ethanolic extracts resulted in the highest inhibition, particularly against fish and tuberculosis-related pathogens, including Mycobacterium marinum. Nanoparticle formation was confirmed using various characterization methods, including ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), which revealed crystalline structures. Transmission electron microscopy (TEM) analysis revealed that AgNPs varied in size, with an average diameter of less than 50 nm and all particles being smaller than 100 nm. This research demonstrates the potential of AgNPs as an effective alternative to antibiotics, offering targeted bacterial inhibition while reducing the risk of antibiotic resistance. This makes it a promising approach for treating bacterial infections in ornamental fish. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Occurrence of Parasitic and Bacterial Pathogen in Ornamental and Wild Populations of Siamese Fighting Fish (Betta splendens) in a Region of Thailand(2025-05-01); The diversity of fish parasites reflects the diversity of parasites in the water source, providing insights into the effects of pathogens and essential information about parasite-host relationships. Parasitic infections are valuable indicators of the aquatic ecosystem, influenced by various factors. This study aimed to investigate the prevalence and seasonality of parasite species and pathogenic bacteria in Siamese fighting fish (Betta splendens) over 12 months, involving sixty ornamental Siamese fighting fish collected from commercial sources and 81 wild Siamese fighting fish from different natural habitats. Parasite prevalence in ornamental Siamese fighting fish (25.00%) was lower than in the wild (34.57%). The protozoa parasite Trichodina was found in both Siamese fighting fish, with the highest prevalence recorded for Trichodina sp. in wild Siamese fighting fish. The winter season exhibited the highest parasitic prevalence, with a tremendous diversity of parasites found at each location, followed by the rainy and summer seasons. This study also reported the first finding of Henneguya sp. infection in Siamese fighting fish and on the body surface. The prevalence and seasonality of parasite genera were significant in the wild compared to ornamental Siamese fighting fish. Bacterial isolation was performed on internal organs, and isolates were identified using PCR techniques. Aeromonas veronii and Mycobacterium marinum were detected in ornamental Siamese fighting fish, while A. veronii was found in wild Siamese fighting fish. These findings indicate that infections in Siamese fighting fish display seasonal variation and are impacted by their ecology. This information is fundamental for managing the biodiversity of parasites in fish and preventing parasite infections in aquaculture. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microwave-Assisted Biosynthesis of Silver Nanoparticles Using Chlorella sp. for Antibacterial and Cytotoxicity Effects of Breast Cancer Cell Line(2026-03-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Ultrathin AlN barrier coatings for enhancing surface chemical stability and suppressing electrochemical migration in immersion silver–finished printed circuit boards(2026-08-15); Immersion silver-finished printed circuit boards (PCB-ImAg) provide low contact resistance and excellent solderability, but their chemical instability in humid and sulfur-containing environments can compromise long-term reliability. In this study, ultrathin aluminum nitride (AlN) films (20–60 nm) were deposited on PCB-ImAg substrates by reactive DC magnetron sputtering as inorganic barrier layers. Their protective performance was evaluated by accelerated H<inf>2</inf>S exposure, long-term ambient air exposure, tape testing, electrical resistance measurements, electrochemical migration (ECM) testing under a 3 V bias at 30 °C and 80% RH, and surface characterization. Uncoated PCB-ImAg samples showed severe tarnishing, Ag<inf>2</inf>S formation, dendritic corrosion, and a marked increase in electrical resistance after both H<inf>2</inf>S and prolonged air exposure. In contrast, AlN-coated samples retained a cleaner surface, remained adherent after the tape test, and showed much smaller resistance changes. X-ray photoelectron spectroscopy detected sulfur-related chemical states only on the uncoated surfaces, indicating suppression of sulfide formation by the AlN layer. A 20 nm AlN coating was sufficient for anti-tarnish and ambient air stability, whereas coatings of 40 nm or greater were required for robust ECM suppression. These results demonstrate that ultrathin AlN films effectively improve the corrosion resistance and ECM reliability of PCB-ImAg surfaces. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Antibacterial activity of marine microalgae extracts against pathogen of Siamese fighting fish (Betta splendens)(2025-01-01); Background: Marine microalgae extracts are a promising alternative to commercial drugs because of their antimicrobial properties. Aim: This study aimed to investigate the antibacterial properties of crude extracts containing bioactive compounds derived from Chlorella sp., Isochrysis galbana, and Chaetoceros calcitrans. Methods: Crude extracts from microalgae were obtained via maceration using ethanol and hexane as solvents. Antibacterial activities were initially screened using the agar well diffusion method, whereas antimycobacterial activity was assessed using the microplate 7H11 agar proportion method. Subsequently, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the crude extracts were determined. Gas chromatographymass spectrometry (GC-MS) was used for phytochemical composition analysis to identify significant antimicrobial compounds in the extracts. Results: The ethanolic extract of I. galbana demonstrated detectable antibacterial activity, with an inhibition zone of 12.40 ± 0.06 mm against Bacillus subtilis, 12.22 ± 0.28 mm against Staphylococcus aureus, 11.10 ± 0.11 mm against Pseudomonas aeruginosa, and 10.99 ± 0.33 mm against Aeromonas veronii at 100 mg/ml. Extracts from I. galbana and C. calcitrans inhibited Mycobacterium marinum, suggesting potential benefits for betta fish health. MIC values were 25 mg/ml for A. veronii in the ethanolic extracts of I. galbana, C. calcitrans, Chlorella sp., and C. calcitrans hexane extract. The GC-MS chromatogram of the ethanolic extract of I. galbana revealed the presence of several bioactive compounds. The major components identified include Phthalate, Tetradecanoic acid, Hexadecanoic acid, and Phytol. Conclusion: This study demonstrated the promising antimicrobial potential of crude extracts from marine microalgae, particularly the ethanolic extract of I. galbana, which showed strong activity against both terrestrial and aquatic pathogens. The findings suggest that bioactive compounds in these extracts, especially those from I. galbana and C. calcitrans, can be effective in managing bacterial infections such as A. veronii and M. marinum in betta fish. These results highlight the potential of marine microalgae as natural, sustainable alternatives for disease control in aquaculture. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Highly transparent flexible CuI film for antibacterial applications(2022-02-01); ; ; In this study, the CuI film was firstly revealed to have significant antibacterial activity. The as-prepared CuI thin films on flexible plastic (polyvinylchloride, PVC) substrates were developed by the liquid iodination method. This method is simple, low-cost and environmentally friendly to fabricate flexible CuI films. A suitable reaction time between the Cu<inf>3</inf>N precursor and aqueous iodine solution is the key parameter for developing highly transparent CuI films, and an average transmittance in visible spectrum was higher than 85%. In addition, the CuI films have prominent antibacterial effects against Staphylococcus aureus and Escherichia coli. These properties indicate that CuI films are promising for built-in application to top layer displays in public places, such as hotel and department stores, ticket machines and touch screens in smart devices. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Effects of Ag-doped Content on Antimicrobial Activity and Substrate Color of Chromium Thin Films Deposited by DC Magnetron Sputtering(2024-10-26); ; Silver ions (Ag<sup>+</sup>) show promise as excellent antimicrobial agents to inhibit microbial growth on high-touch surfaces. In this study, Ag-doped Cr films were deposited using a DC magnetron sputtering system from a mosaic target. The Cr-Ag mosaic target was a 0.125-inch-thick Cr base (99.95% pure) with different diameters of Ag circle sheets mounted on the Cr target. The sputtering condition was kept at a DC power of 100W, working pressure of 8.3x10<sup>-3</sup> mbar with Ar as the sputtering gas, and sputtering times of 15 and 30 min. The antimicrobial activity and efficiency were determined by standard testing (JIS Z 2801: 2000). The antibacterial performance was calculated from the antibacterial inhibition of the Ag-doped Cr films in bacterial solution (Staphylococcus aureus and Escherichia coli) after 24 h. The results showed that the Ag content was between 0.27 at% and 6.11 at% depending on the diameter of Ag and the deposition time. The minimum Ag content of 4.05 at% had an inhibition efficiency of 99.98% (E. coli) and 96.33% (S. aureus). The contact angle testing of Ag-doped Cr films showed hydrophobic behavior with the angle greater than 90 degrees. The optical color of the Ag-doped films was characterized by UV-vis spectroscopy (CIE testing). The film colors were significantly changed by the addition of Ag into the Cr films. The total color difference (∆E) increased by 3-10 units compared to the reference chromium film and the Ag doping mainly affected +L* (Lightness).1