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Micromachines Jun 2024This study investigated the influence of microstructure on the performance of Ag inkjet-printed, resistive temperature detectors (RTDs) fabricated using particle-free...
This study investigated the influence of microstructure on the performance of Ag inkjet-printed, resistive temperature detectors (RTDs) fabricated using particle-free inks based on a silver nitrate (AgNO) precursor and ethylene glycol as the ink solvent. Specifically, the temperature coefficient of resistance (TCR) and sensitivity for sensors printed using inks that use monoethylene glycol (mono-EG), diethylene glycol (di-EG), and triethylene glycol (tri-EG) and subjected to a low-pressure argon (Ar) plasma after printing were investigated. Scanning electron microscopy (SEM) confirmed previous findings that microstructure is strongly influenced by the ink solvent, with mono-EG inks producing dense structures, while di- and tri-EG inks produce porous structures, with tri-EG inks yielding the most porous structures. RTD testing revealed that sensors printed using mono-EG ink exhibited the highest TCR (1.7 × 10/°C), followed by di-EG ink (8.2 × 10/°C) and tri-EG ink (7.2 × 10/°C). These findings indicate that porosity exhibits a strong negative influence on TCR. Sensitivity was not strongly influenced by microstructure but rather by the resistance of RTD. The highest sensitivity (0.84 Ω/°C) was observed for an RTD printed using mono-EG ink but not under plasma exposure conditions that yield the highest TCR.
PubMed: 38930719
DOI: 10.3390/mi15060749 -
Biomedicines Jun 2024Three berberine-containing plant extracts were investigated for their pharmacological properties. The stems and leaves of , , and were characterized through scanning...
Three berberine-containing plant extracts were investigated for their pharmacological properties. The stems and leaves of , , and were characterized through scanning electron microscopy. The plant extracts obtained from fresh stem barks were further analyzed through high-performance liquid chromatography, revealing berberine concentrations, among berbamine and palmatine. The plant extracts were further tested for their anticancer potential against 2D and 3D human skin melanoma (A375) and lung adenocarcinoma (A549) cell lines. The concentrations at which 50% of the cells are affected was determined by the viability assay and it was shown that , the plant extract with the highest berberine concentration, is the most efficient inhibitor (0.4% extract concentration for the 2D model and 3.8% for the 3D model). The membrane integrity and nitrate/nitrite concentration assays were consistent with the viability results and showed effective anticancer potential. For further investigations, the extract was used to obtain silver nanoparticles, which were characterized through transmission electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The formed nanoparticles have a uniform size distribution and are suited for future investigations in the field of biomedical applications, together with the plant extract.
PubMed: 38927546
DOI: 10.3390/biomedicines12061339 -
Antibiotics (Basel, Switzerland) May 2024Silver has been shown to improve the antibiotic effects of other drugs against both Gram- positive and -negative bacteria. In this study, we investigated the antibiotic...
Silver has been shown to improve the antibiotic effects of other drugs against both Gram- positive and -negative bacteria. In this study, we investigated the antibiotic potential of cannabidiol (CBD), cannabichromene (CBC) and cannabigerol (CBG) and their acidic counterparts (CBDA, CBCA, CBGA) against Gram-positive bacteria and further explored the additive or synergistic effects of silver nitrate or silver nanoparticles using 96-well plate growth assays and viability (CFUs- colony-forming units). All six cannabinoids had strong antibiotic effects against MRSA with minimal inhibitory concentrations (MICs) of 2 mg/L for CBG, CBD and CBCA; 4 mg/L for CBGA; and 8 mg/L for CBC and CBDA. Using 96-well checkerboard assays, CBC, CBG and CBGA showed full or partial synergy with silver nitrate; CBC, CBDA and CBGA were fully synergistic with silver nanoparticles against MRSA. Using CFU assays, combinations of CBC, CBGA and CBG with either silver nitrate or silver nanoparticles, all at half or quarter MICs, demonstrated strong, time-dependent inhibition of bacterial growth (silver nitrate) and bactericidal effects (silver nanoparticles). These data will lead to further investigation into possible biomedical applications of specific cannabinoids in combination with silver salts or nanoparticles against drug-resistant Gram-positive bacteria.
PubMed: 38927140
DOI: 10.3390/antibiotics13060473 -
ACS Nano Jun 2024Cation exchange is a versatile method for modifying the material composition and properties of nanostructures. However, control of the degree of exchange and material...
Cation exchange is a versatile method for modifying the material composition and properties of nanostructures. However, control of the degree of exchange and material properties is difficult at the single-particle level. Successive cation exchange from CdSe to AgSe has been utilized here on the same individual nanowires to monitor the change of electronic properties in field-effect transistor devices. The transistors were fabricated by direct synthesis of CdSe nanowires on prepatterned substrates followed by optical lithography. The devices were then subjected to cation exchange by submerging them in an exchange solution containing silver nitrate. By removal of the devices from solution and probing the electrical transport properties at different times, the change in electronic properties of individual nanowires could be monitored throughout the entire exchange reaction from CdSe to AgSe. Transistor characterization revealed that the electrical conductivity can be tuned by up to 8 orders of magnitude and the charge-carrier mobility by 7 orders of magnitude. While analysis of the material composition by energy dispersive X-ray spectroscopy confirmed successful cation exchange from CdSe to AgSe, X-ray fluorescence spectroscopy proved that cation exchange also took place below the contacts. The method presented here demonstrates an efficient way to tune the material composition and access the resulting properties nondestructively at the single-particle level. This approach can be readily applied to many other material systems and can be used to study the electrical properties of nanostructures as a function of material composition or to optimize nanostructure-based devices after fabrication.
PubMed: 38916252
DOI: 10.1021/acsnano.4c05197 -
Journal of Materials Chemistry. B Jun 2024Bacterial infections and the emergence of super-resistant bacteria pose a significant risk to human health. Effective sterilization to prevent the development of...
Bacterial infections and the emergence of super-resistant bacteria pose a significant risk to human health. Effective sterilization to prevent the development of bacterial drug resistance remains a challenge. Herein, curcumin/silver/montmorillonite (Cur/Ag/Mt) was prepared through a green chemical reduction method with montmorillonite as the carrier, curcumin as the reducing agent and the capping agent, and citric acid as the structure guide agent. Then, a novel dual light-responsive and thermosensitive Pluronic F127-based hydrogel (CAM-F) was prepared by encapsulating Cur/Ag/Mt within the F127 hydrogel. The Cur/Ag/Mt showed strong absorption in the near-infrared region that efficiently converts light into heat for photothermal therapy when the molar ratio of curcumin to silver nitrate was 2 : 1. Specifically, triangular silver nanoparticles reduced by curcumin were immobilized on the Mt layers, which could enhance photodynamic therapy by the metal-enhanced singlet oxygen and metal-enhanced fluorescence mechanisms. Upon combining 405 nm and 808 nm laser irradiation, the CAM-F hydrogel could simultaneously generate reactive oxygen species, increase the local temperature, and sustain the release of Ag, thus displaying excellent bactericidal performance against Gram-negative and Gram-positive bacteria. The antibacterial rates of CAM-F hydrogels were 99.26 ± 0.95% and 99.95 ± 0.98% for and , respectively. The findings suggest the potential of the CAM-F hydrogel as a stable, biologically safe, and broad-spectrum antimicrobial material. The thermosensitive CAM-F hydrogels for synergetic phototherapy may provide a promising strategy for solving clinical problems caused by pathogenic infections.
PubMed: 38912877
DOI: 10.1039/d4tb00431k -
Journal of Indian Association of... 2024This study aims to compare the efficacy and safety of topical application of common salt (CS) in comparison to silver nitrate (SN) for treating infants with umbilical...
AIM
This study aims to compare the efficacy and safety of topical application of common salt (CS) in comparison to silver nitrate (SN) for treating infants with umbilical granuloma (UG).
MATERIALS AND METHODS
We conducted an open-label, prospective, single-center, pilot randomized controlled trial. Thirty-seven infants with a clinical UG diagnosis were enrolled between October 2022 and July 2023, excluding those previously treated for UG. Patients were randomly assigned (using the Randomizer app) to receive either topical CS (applied thrice daily by caregivers at home for 5 days) or SN (applied by pediatric surgeon in clinic and kept under occlusive dressing for 48 h). Patients with partial/no healing received an additional session of the same treatment. Nonresponders transitioned from CS to SN, and vice versa, for two more applications. Healing rates were compared with a significance level of α =0.05.
RESULTS
Out of 34 patients (18 CS and 16 SN), 32 successfully completed the trial (17 CS and 15 SN). No significant differences were observed in baseline characteristics. Efficacy rates of CS (19/22; 86.36%) and SN (11/17; 64.71%) did not significantly differ ( = 0.056; 95% confidence interval [CI] -0.4832-0.0502). No major adverse events were reported. CS showed superior healing outcomes in infants below 3 months of age (19/22; 86.36%) compared to SN (11/17; 64.71%) ( = 0.056; 95% CI - 0.4832-0.0502). The timing of umbilical cord detachment did not significantly affect healing rates.
CONCLUSION
Widespread availability, ease of access, suitability for safe home application, and cost-effectiveness make CS a primary treatment option for UG. Larger patient cohorts are needed for conclusive results.
PubMed: 38912018
DOI: 10.4103/jiaps.jiaps_209_23 -
International Journal of Biological... Jun 2024In this work, bacterial cellulose (BC) derived from Nata de Coco is a polysaccharide material, and it is further processed into bacterial cellulose nanocrystal (BCNC)...
In this work, bacterial cellulose (BC) derived from Nata de Coco is a polysaccharide material, and it is further processed into bacterial cellulose nanocrystal (BCNC) via acid hydrolysis. Then BCNC is doped with transition metals to enhance its amine/hydrogen sulfide response. Therefore, the aim of this study is to investigate the use of transition metals as indicators to detect amine and hydrogen sulfide gas for efficiently monitoring food spoilage. BCNCs were treated with various concentrations of silver nitrate (AgNO) and copper sulfate pentahydrate (CuSO·5HO). Then the dropwise addition of ascorbic acid was applied to reduce Ag and Cu to Ag (silver nanoparticle) and Cu (copper nanoparticle), which refer to red brown and red wine colors, respectively. The results indicated that BCNC/Ag nanoparticles were spherical, while BCNC/Cu nanoparticles exhibited a rod-like structure. XRD results also presented the incorporation of Ag and Cu nanoparticles, as confirmed by both crystallography structures. Furthermore, UV-Vis spectra showed the adsorption bands at 422-430 nm and 626-629 nm, belonging to Ag and Cu nanoparticles. After HS and ammonia gas exposure, BH/Ag and BH/Cu films turned black from brown and red. In conclusion, transition metal-doped BCNCs exhibit potential for innovative food spoilage gas sensors.
PubMed: 38908632
DOI: 10.1016/j.ijbiomac.2024.133248 -
RSC Advances Jun 2024Heavy metals exist in different water resources and can threaten human health, inducing several chronic illnesses such as cancer and renal diseases. Therefore, this work...
Improvement of hybrid polyvinyl chloride/dapsone membrane using synthesized silver nanoparticles for the efficient removal of heavy metals, microorganisms, and phosphate and nitrate compounds from polluted water.
Heavy metals exist in different water resources and can threaten human health, inducing several chronic illnesses such as cancer and renal diseases. Therefore, this work dealt with the fabrication of highly efficient nanomembranes based on silver nanoparticle (Ag NP)-doped hybrid polyvinyl chloride (PVC) by dapsone (DAP) using an method. Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction (XRD) analysis were used to confirm the hybridization of PVC as well as the crystalline structure of hybrid PVC nanocomposites. Three varying proportions of Ag NPs (, 0.1, 0.2, and 0.3%) were used to fabricate hybrid PVC-DAP nanomembranes. The Brunauer-Emmet-Teller (BET) method was used to estimate membrane surface area, porosity and distribution of pore volume. The mechanical strength and antibacterial properties of the cased films notably improved when Ag NPs were added depending on the NP ratio inside the matrix. Results obtained from adsorption experiments of PVC-DAP nanomembranes at 35 °C revealed that the optimum nanomembrane was achieved at 0.2% NPs and its percentage of removal effectiveness ranged from 71 to 95% depending on the ion type. The surface morphology of the PVC-DAP-0.2 Ag NPs before and after the adsorption process of the metal ions was analyzed using SEM-EDX. Moreover, the impact of other parameters such as the initial concentrations, pH media, temperature, and contacting time, on the adsorption efficiency of PVC-DAP-0.2 Ag NPs was also investigated. Furthermore, kinetic and adsorption isotherm models were suggested to describe the adsorption efficiency of the PVC-DAP-0.2 Ag NP membrane, and the uptake mechanism of metal ion removal was studied. The obtained outcomes for these fabricated nanomembranes demonstrated that they could be potential candidates for water purification and other potential purposes including biomedical areas.
PubMed: 38899035
DOI: 10.1039/d4ra03810j -
Polymers May 2024Pomegranate waste poses an environmental challenge in Arequipa. Simultaneously, interest in sustainable materials like natural rubber latex (NRL) is growing, with...
Pomegranate waste poses an environmental challenge in Arequipa. Simultaneously, interest in sustainable materials like natural rubber latex (NRL) is growing, with Peruvian communities offering a promising source. This study explores the green synthesis of silver nanoparticles (AgNPs) using pomegranate peel extract and their incorporation into NRL nanofibers for enhanced functionalities. An eco-friendly process utilized silver nitrate and pomegranate peel extract as a reducing and capping agent to synthesize AgNPs. The resulting AgNPs and NRL/AgNPs nanofibers were characterized using imaging and spectroscopic techniques such as UV-vis, TGA, FTIR, XRD, Raman, SEM, and DLS. Green-synthesized AgNPs were spherical and crystalline, with an average diameter of 59 nm. They showed activity against , , , and (IC50: 51.32, 4.87, 27.72, and 69.72 µg/mL, respectively). NRL and NRL/AgNPs nanofibers (300-373 nm diameter) were successfully fabricated. The composite nanofibers exhibited antibacterial activity against and . This study presents a sustainable approach by utilizing pomegranate waste for AgNP synthesis and NRL sourced from Peruvian communities. Integrating AgNPs into NRL nanofibers produced composites with antimicrobial properties. This work has potential applications in smart textiles, biomedical textiles, and filtration materials where sustainability and antimicrobial functionality are crucial.
PubMed: 38891477
DOI: 10.3390/polym16111531 -
PloS One 2024Rice (Oryza sativa) stands as a crucial staple food worldwide, especially in Bangladesh, where it ranks as the third-largest producer. However, intensified cultivation...
Rice (Oryza sativa) stands as a crucial staple food worldwide, especially in Bangladesh, where it ranks as the third-largest producer. However, intensified cultivation has made high-yielding rice varieties susceptible to various biotic stresses, notably sheath blight caused by Rhizoctonia solani, which inflicts significant yield losses annually. Traditional fungicides, though effective, pose environmental and health risks. To address this, nanotechnology emerges as a promising avenue, leveraging the antimicrobial properties of nanoparticles like silver nanoparticles (AgNPs). This study explored the green synthesis of AgNPs using Ipomoea carnea leaf extract and silver nitrate (AgNO3), and also examined their efficacy against sheath blight disease in rice. The biosynthesized AgNPs were characterized through various analytical techniques such as UV-vis spectrophotometer, X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Particle size analyzer, Zeta potential, Scanning Electron Microscope (SEM), Field Emission Scanning Electron Microscope (FESEM), Transmission Electron Microscope (TEM) for confirming their successful production and crystalline nature of nanoparticles. The results of UV-visible spectrophotometers revealed an absorption peak ranging from 421 to 434 nm, validated the synthesis of AgNPs in the solution. XRD, DLS, and TEM estimated AgNPs sizes were ~45 nm, 66.2nm, and 46.38 to 73.81 nm, respectively. SEM and FESEM demonstrated that the synthesized AgNPs were spherical in shape. In vitro assays demonstrated the significant inhibitory effects of AgNPs on mycelial growth of Rhizoctonia solani, particularly at higher concentrations and pH levels. Further greenhouse and field experiments validated the antifungal efficacy of AgNPs against sheath blight disease in rice, exhibiting comparable effectiveness to commercial fungicides. The findings highlight the potential of AgNPs as a sustainable and effective alternative for managing rice sheath blight disease, offering a safer solution amidst environmental concerns associated with conventional fungicides.
Topics: Rhizoctonia; Oryza; Silver; Metal Nanoparticles; Plant Diseases; Green Chemistry Technology; X-Ray Diffraction; Plant Extracts; Fungicides, Industrial
PubMed: 38889131
DOI: 10.1371/journal.pone.0304817