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In order to enhance the sensing performance of the NO2 sensor, La0.8Sr0.2Co0.2Fe0.8O3-δ (LSCF) and LSCF+0.050Ag, LSCF+0.075Ag, LSCF+0.100Ag biphasic sensing electrodes were prepared by the self-demixing method, and the impedance spectrum type NO2 sensor was successfully prepared with YSZ as the solid electrolyte. The effect of Ag doping on the performance of the sensor was studied. The results show that compared with Z′, Z″ and |Z|, when θ is used as the response signal, the response recovery time of the sensor is shorter and the response signal is more stable. The resutts show that using θ as the response signal, the sensitivities of the sensors based on LSCF, LSCF+0.050Ag, LSCF+0.075Ag and LSCF+0.100Ag sensitive electrodes are 11.12°, 11.28°, 13.62° and 9.56° at the optimal operating temperature of 450 ℃, and the sensitivity of LSCF+0.075Ag is higher. The sensor also exhibits excellent reproducibility and long-term stability. In addition, the sensor shows excellent immunity to CH4, CO2, H2, CO and NH3. Therefore, the preparation of biphasic sensing electrode materials with a homogeneous distribution of the second phase and excellent catalytic activity by the self-demixing method effectively improves the sensitivity and selectivity of the sensor, which provides a new idea for the preparation of high-performance NO2 sensors.

Plaque control is especially important during orthodontic treatment because areas of the teeth near brackets and wires are difficult to clean with a toothbrush, resulting in debris buildup of food or dental plaque, thus causing caries and periodontal disease. The objective of this study was to evaluate the antimicrobial properties of silver nanoparticles (AgNPs), titanium dioxide nanoparticles (TiO2NPs), and silver/titanium dioxide nanoparticles (Ag/TiO2NPs), synthesized on the surface of α-alumina ceramic brackets. The AgNPs and TiO2NPs were synthesized by a simple chemical method, and these were characterized by XRD, SEM, and XPS TEM; the antimicrobial activity was tested against Staphylococcus aureus and Escherichia coli by diffusion test. The results of this study demonstrated that by this simple chemical method, silver and titanium dioxide nanoparticles can be synthesized on the surface of α-alumina esthetic brackets, and these NPs possess good antimicrobial activity and the possibility of reducing dental caries, periodontal disease, and white spot generated during orthodontic treatment.

Cu6Sn5-xAg alloys (x = 0, 3, 6; %, mass fraction) were synthesized using Ag as a dopant through a high-temperature melting technique. The microstructure of the alloy was analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and other equipment, while the hardness of the alloy was measured to investigate the impact of Ag addition on the structure and microstructure of the Cu6Sn5 intermetallic compound. This study explored the influence of varying Ag contents on the properties of Cu6Sn5 intermetallic compounds, with calculations based on first principles revealing the mechanical properties and density of states of η′-Cu6Sn5 and its Ag-doped systems. The results indicated that Cu6Sn5-xAg alloys predominantly existed in three distinct forms, all exhibiting large masses without any impurities or precipitates. First-principle calculations demonstrated that Ag substitution in certain sites suppressed the anisotropy of the Young’s modulus of Cu6Sn5, particularly in the Cu1, Cu3, Sn1, and Sn3 positions, while the effect was less significant at the Cu2, Cu4, and Sn2 sites. The introduction of Ag through doping enhanced the covalent bonding within the η′-Cu6Sn5 structure, promoting the formation of a stable (Cu, Ag)6Sn5 structure.

An in-depth analysis of a solar cell with a photoanode made of glass/FTO/TiO2, and Ag- CdSe quantum dots (QD) nanocomposite, an electrolyte of iodide and triiodide, and a Pt electrode is presented in this work. We looked at how CdSe QD filling factors and Ag nanoparticles affect the solar cell's ability to absorb light. Additionally, the effects of nanocomposite layer thicknesses, Iodide/triiodide layer thicknesses, and TiO2 layer thicknesses on the absorption are investigated. It has been discovered that the Ag nanoparticles have an effect on the absorbance around 700 nm, dropping around 800 nm while keeping the range from 400 nm to 600 nm constant as the fraction of silver increases. With the switch to CdSe, the solar cell's performance was only marginally altered. When the composite thickness is increased to 200 nm, the value of A has the highest values and is expanded to include longer wavelengths. While altering the thickness of the iodide/triiodide layer (di) causes the highest values of A to expand at di = 200 nm. However, the performance of the solar cell is unaffected by the TiO2 layer's thickness (dt). As a result, we gave a solar cell the variables that impacted its performance.

SUMMARY: Switch defective/sucrose non‐fermentable (SWI/SNF) chromatin remodeling complexes are evolutionarily conserved, multi‐subunit machinery that play vital roles in the regulation of gene expression by controlling nucleosome positioning and occupancy. However, little is known about the subunit composition of SPLAYED (SYD)‐containing SWI/SNF complexes in plants. Here, we show that the Arabidopsis thaliana Leaf and Flower Related (LFR) is a subunit of SYD‐containing SWI/SNF complexes. LFR interacts directly with multiple SWI/SNF subunits, including the catalytic ATPase subunit SYD, in vitro and in vivo. Phenotypic analyses of lfr‐2 mutant flowers revealed that LFR is important for proper filament and pistil development, resembling the function of SYD. Transcriptome profiling revealed that LFR and SYD shared a subset of co‐regulated genes. We further demonstrate that the LFR and SYD interdependently activate the transcription of AGAMOUS (AG), a C‐class floral organ identity gene, by regulating the occupation of nucleosome, chromatin loop, histone modification, and Pol II enrichment on the AG locus. Furthermore, the chromosome conformation capture (3C) assay revealed that the gene loop at AG locus is negatively correlated with the AG expression level, and LFR‐SYD was functional to demolish the AG chromatin loop to promote its transcription. Collectively, these results provide insight into the molecular mechanism of the Arabidopsis SYD‐SWI/SNF complex in the control of higher chromatin conformation of the floral identity gene essential to plant reproductive organ development. Significance Statement: This study provides insight into the molecular mechanism of the Arabidopsis SYD‐SWI/SNF complex in the control of higher chromatin conformation of the floral identity gene essential to plant reproductive organ development. [ABSTRACT FROM AUTHOR]

Copyright of Eurasian Physical Technical Journal is the property of E.A. Buketov Karaganda University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Bi2MoO6/TiO2 and Bi2MoO6/Ag/TiO2 composites were solvothermally synthesized and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and (high resolution) transmission electron microscopy ((HR)TEM). The Bi2MoO6/TiO2 and Bi2MoO6/Ag/TiO2 composites exhibited higher photocatalytic activity than pure Bi2MoO6. 100% of the RhB dye molecules could be decomposed over Bi2MoO6/Ag/TiO2 composite in 120 min. The enhanced photocatalytic activity of Bi2MoO6/TiO2 and Bi2MoO6/Ag/TiO2 composite was attributed to the efficient separation of photoinduced electrons and holes. The mechanism for the enhanced photocatalytic activity is discussed. [ABSTRACT FROM AUTHOR]

As an efficient, safe, and environmentally friendly technology, semiconductor photocatalysis has been widely used in the removal of antibiotics from wastewater. In this work, a novel Ag/BiOI/g‐C3N4 composite photocatalytic material, BiOI/g‐C3N4, g‐C3N4, and BiOI are prepared as the photocatalysts. The morphologies, chemical properties, and photocatalytic performances of the photocatalysts are characterized using scanning electron microscope, transmission electron microscope, X‐ray diffraction, X‐ray photoelectron spectroscopy, Fourier‐transform infrared spectrometer, ultraviolet–visible spectroscopy (UV–Vis) diffuse reflectance spectra, and photoluminescence spectra. In addition, tetracycline hydrochloride (TC) and ceftiofur sodium aqueous solutions are used to simulate wastewater and the photocatalytic degradation performances of the photocatalysts are investigated and compared under visible light. Compared to g‐C3N4, BiOI, and BiOI/g‐C3N4, the Ag/BiOI/g‐C3N4 demonstrates superior performance, increasing the removal rates of TC and ceftiofur sodium to 85.6% and 90.2%, respectively. The photocatalytic mechanism of the Ag/BiOI/g‐C3N4 may involve the promotion of the visible light–harvesting ability and inhibition of the recombination of photogenerated electron/hole pairs. Furthermore, the primary active groups in the system are identified as superoxide radicals (·O2−) and hydroxyl radicals (·OH). Herein, some valuable insights into the development of innovative photocatalytic materials are offered for the effective removal of antibiotics from water. [ABSTRACT FROM AUTHOR]

Antibiotic resistance is one of the biggest public health problems of our time. The nanoparticles are a powerful alternative to these antibiotics. Engineered nanoparticles show toxic effects on bacteria by different mechanisms. The bacteria–cell interaction of engineered nanoparticles exerts their toxic effects through changes in cell wall, cell membrane, and cytoplasm content/density. Thus, death occurs as a result of cell deformation. In this study, the cellular damage of silver nanoparticles, which are known to have strong antibacterial properties, and zirconium oxide and silicon oxide engineering nanoparticles, which are less known, on periodontopathic (Prevotella intermedia and Aggregatibacter actinomycetemcomitans) bacteria, were investigated by ultrastructural changes. The lysis of the cytoplasm and separation of the membrane cytoplasm were observed. Both types of bacteria treated with Ag ENP show more hollow cytoplasm than bacteria treated with the other two nanoparticles. [ABSTRACT FROM AUTHOR]

Abstract Background This study aimed to evaluate bone response to micro-arc oxidation coated titanium alloy implants containing Ag. Methods 144 titanium alloy implants were prepared by machine grinding and divided into three treatment groups as following, SLA group: sand-blasting and acid-etched coating; MAO group: micro-arc oxidation without Ag coating; MAO + Ag group: micro-arc oxidation containing Ag coating. Surface characterization of three kind of implants were observed by X-ray diffraction, energy dispersive X-ray spectrometer, scanning electron microscopy, High Resolution Transmission Electron Microscope and roughness analysis. The implants were inserted into dog femurs. 4, 8 and 12 weeks after operation, the bone response to the implant to the bone was evaluated by push-out experiment, histological and fluorescent labeling analysis. Results MAO + Ag group consisted of a mixture of anatase and rutile. Ag was found in the form of Ag2O on the surface. The surface morphology of MAO + Ag group seemed more like a circular crater with upheaved edges and holes than the other two groups. The surface roughness of MAO and MAO + Ag groups were higher than SLA group, but no statistical difference between MAO and MAO + Ag groups. The contact angles in MAO + Ag group was smallest and the surface free energy was the highest among three groups. The maximum push-out strength of MAO and MAO + Ag groups were higher than SLA group at all time point, the value of MAO + Ag group was higher than MAO group at 4 and 8 weeks. Scanning electron microscopy examination for the surface and cross-section of the bone segments and fluorescent labeling analysis showed that the ability of bone formation and osseointegration in MAO + Ag group was higher than that of the other two groups. Conclusion The micro-arc oxidation combination with Ag coating is an excellent surface modification technique to posse porous surface structure and hydrophilicity on the titanium alloy implants surface and exhibits desirable ability of osseointegration.

In this work, CuBi 2 O 4 IOs-Ag catalyst with the effect of surface plasmon resonance and the structure of inverse opal is designed for photoelectrocatalytic CO 2 to CO with the Faraday efficiency of 92% at 0.2 V vs. RHE, and this value is roughly 1.6 times that of the pristine CuBi 2 O 4 thin film. [Display omitted] • CuBi 2 O 4 inverse opal structure show high light capture and mass transfer efficiency. • Plasmonic Ag nanoparticles improves the PEC-CO 2 RR to CO kinetics. • CuBi 2 O 4 IOs -Ag improve the carrier dynamics by forming an ohmic contact. • The photocathode has the best selectivity for CO with a FE of 92% at 0.2 V vs. RHE. • It also has short depletion layer width and extended carrier recombination lifespan. Low light absorption efficiency and short carrier diffusion length mainly restrict the use of CuBi 2 O 4 as a photocathode for an efficient photoelectrocatalytic CO 2 reduction reaction (PEC-CO 2 RR). These inadequacies are alleviated by fabricating CuBi 2 O 4 inverse opal photocathode modify with plasmonic Ag nanoparticles (CuBi 2 O 4 IOs-Ag) by using a sacrificing template method. The CuBi 2 O 4 IOs-Ag photocathode exhibits superior PEC-CO 2 RR-to-CO performance with a Faraday efficiency (FE) of 92% at 0.2 V versus reversible hydrogen electrode, and this value is roughly 1.6 times that of the pristine CuBi 2 O 4 thin film. Detail characterization and experiments reveal that the exceptional three-dimensional (3D) order structure simultaneously accelerates the mass transfer rates and enhances the light-harvesting efficiency. In addition, the introduction of Ag nanoparticles remarkably improves the surface charge distribution by forming an ohmic contact with CuBi 2 O 4. Consequently, carrier recombination is efficiently inhibited, and the carrier dynamics behavior is improved. This work provides important insights into the design of high-performance photoelectrocatalytic systems for CO 2 reduction by engineering the microstructure of catalysts with localized surface plasmon resonance effect. [ABSTRACT FROM AUTHOR]

Developing cheap and efficient catalysts is the key to develop electrolytic water industry. Layered double hydroxides (LDH) exhibit excellent performance in electrocatalytic oxygen evolution reactions, but these catalysts exhibit poor electrochemical performance in hydrogen evolution reactions. Excellent hydrogen evolution performance was achieved by doping Ag element into NiFe-LDH nanosheet arrays. The results show that in 1 mol/L KOH solution, the required overpotential for a current density of 10 mA·cm-2 is only 73 mV, and the Tafel slope is 61. 3 mV·dacade-1. At a high current density of 800 mA·cm-2, the overpotential is only 493 mV, which is significantly lower than that of commercial platinum carbon catalysts. After 30 h of stability testing, the electrochemical performance remains above 90%. The improvement in catalytic performance is attributed to the reduction in nanosheet size and increase in specific surface area caused by Ag doping with NiFe-LDH, which effectively enhances hydrogen production kinetics and improves electron transport, thereby optimizing the electrocatalytic hydrogen evolution performance of NiFe-LDH. [ABSTRACT FROM AUTHOR]

The field of optical thin films has garnered significant attention due to their potential applications in visible light communication, optical sensing, and imaging. Among the various fabrication methods available, conventional layer-by-layer (LBL) dip coating is less sophisticated and more economical. Nevertheless, this approach frequently encounters deficiencies in the precise control of the growth of thin films. This work aimed at properly comprehending the growth conditions associated with the LBL dip coating process and optimizing the conditions to obtain the best thin film growth for different materials: metallic (Ag), semiconducting (ZnO), and insulating (SiO2). The optimization of the conditions for surface functionalization with 3-aminopropyltriethoxysilane (APTES) together with other parameters like dipping time, drying time, the number of dipping–drying cycles, and the timing of the intermediate APTES layers led to the controlled growth of thin films. Atomic force microscopy and scanning electron microscopy revealed even deposition in the case of ZnO and SiO2 from the very beginning, while with Ag NPs, the growth of the thin film was observed to be uneven and gradually became smooth as the number of layers increased, and a smooth layer could be observed after over 100 layers of dipping. [ABSTRACT FROM AUTHOR]

Novel Ag/Fe2O3/BiOI Z-scheme heterostructures are first fabricated through a facile hydrothermal method. The composition and properties of as-synthesized Ag/Fe2O3/BiOI nanocomposites are characterized by powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, UV-Vis diffuse reflectance spectra, etc. The Ag/Fe2O3/BiOI systems exhibit remarkable degradation performance for tetracycline (TC). In particular, the composite (Ag/Fe2O3/BiOI-2) shows the highest efficiency when the contents of Ag and α-Fe2O3 are 2 wt% and 15%, respectively. The effects of operating parameters, including the solution pH, H2O2 concentration, TC concentration, and catalyst concentration, on the degradation efficiency are investigated. The photo-Fenton mechanism is studied, and the results indicated that •O2− is the main active specie for TC degradation. The enhanced performance of Ag/Fe2O3/BiOI heterostructures may be ascribed to the synergic effect between photocatalysis and the Fenton reaction. The formation of Ag/Fe2O3/BiOI heterojunction is beneficial to the transfer and separation of charge carriers. The photo-generated electrons accelerate the Fe2+/Fe3+ cycle and create the reductive reaction of H2O2. This research reveals that the Ag/Fe2O3/BiOI composite possesses great potential in wastewater treatment. [ABSTRACT FROM AUTHOR]

Coal-based SiO2/GO nanosheets were prepared by modified Hummers method using Xinjiang Wucaiwan coal as raw materials. According the characterization tests results, graphite-like crystal structures had formed. Meanwhile, the Si elements presented in coal could form SiO2 particles during the oxidation process and loaded onto the GO surface in situ to produce structurally stable coal-based SiO2/GO sheets which is quite advantageous as carrier. Ag nanoparticles prepared by thermal reduction was loaded on the surface of coal-based SiO2/GO. The structure of Ag/SiO2/GO was characterized, and the photocatalytic performance of nitrogen fixation to ammonia was discussed. It was found that coal-based SiO2/GO as a carrier not only improved the dispersion of Ag nanoparticles through avoiding the agglomeration, but also improved the absorption of visible light of the composite photocatalyst, which in turn improved the performance of Ag/SiO2/GO for ammonia synthesis. The ammonia yield reached 449.32 μmol L−1 g−1·cat when 80%-Ag/SiO2/GO was used as photocatalyst reacting for 4 h. Besides, the composite photocatalyst had good stability and lifetime. The ammonia yield could still reach 82.49% after five cycles. [ABSTRACT FROM AUTHOR]

Dopamine was used to modify polytetrafluoroethylene (PTFE) in order to obtain functional polydopamine (PDA) surface-modified PTFE microporous film (PTFE@PDA). Ag was deposited on the surface of PTFE@PDA using electroless plating in order to obtain Ag-wrapped PTFE@PDA film (PTFE@Ag). A liquid-phase chemical reduction method was employed to prepare nickel nanochains. A Ni@PVDF cast film was obtained by mechanically blended nickel nanochains and polyimide (PVDF). The above two films were hot pressed to give a flexible, ultra-thin, and highly effective electromagnetic shielding composite film with a "3+2" layered structure. IR, XRD, and TEM results showed the PTFE@PDA film surface was coated by a tight plating layer of Ag particles with a particle size of 100~200 nm. PTFE@Ag+Ni@PVDF composite film exhibited excellent electromagnetic shielding effectiveness, with the conductivity of 7507.5 S/cm and the shielding effectiveness of 69.03 dB in the X-band range. After a 2000-cycle bending, this value still remained at 51.90 dB. Furthermore, the composite film presented excellent tensile strength of 62.1 MPa. It has great potential for applications in flexible and wearable intelligent devices. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesised silver nanoparticles (Ag NPs) using the leaf extract of Ficus religiosa. The Ag NPs were incorporated with biochar (derived from algal biomass powder) and used as an electrode material for supercapacitors. The presence of different phytochemicals in the leaf extract of Ficus religiosa was confirmed using different phytochemical tests. The prepared nanocomposite (Biochar/Ag) was analysed using different analytical methods. Galvanostatic charge–discharge, electrochemical impedance analysis, and cyclic voltammetry have all been used in the electrochemical investigation. The maximum specific capacitance of Biochar/Ag was calculated to be 675 F/g. The cyclic stability of Biochar/Ag was observed to be 96.1% after 5000 GCD cycles under three electrode systems. The maximum power density of Biochar/Ag has been found to be 3168 W/kg. The developed Biochar/Ag can be utilised as an effective and low-cost electrode material for supercapacitors. [ABSTRACT FROM AUTHOR]

SF6/N2 mixture gas is an environmentally friendly sealing gas for power equipment. The multiple arc erosion performance of Ag/Ti3SiC2 composite was investigated in SF6/N2. During the multiple arc erosion process, the relative breakdown strength increased with the operation number, and the breakdown current and arc duration were randomly distributed in a certain range. Ag spheres were observed on the material surface in the arc erosion region. For the Ti3SiC2 reinforcing phase, a silicon de-intercalation phenomenon was observed in the eroded region. Additionally, instantaneous photographs of the arc erosion process were recorded. [ABSTRACT FROM AUTHOR]

The unique surface, optical and photocatalytic properties of nanomaterials based on various oxide nanoparticles have found wide application in wastewater treatment. In a number of modern scientific studies, bioactive catalysts based on TiO2, which exhibit redox activity in water purification, were considered. The presented structures based on titanium dioxide, formed in binary and ternary systems in the presence of silver and cerium with a different degree of crystallinity were obtained by the chemical precipitation method using titanium tetraisopropoxide (TTIP) as a precursor species. XRD data confirmed a homogeneous composition of powders formed in binary systems (anatase with clusters of Ag and CeO2) with CSR in the range of 9-20 nm. It was stated that in ternary systems, with an increase in the content of doping components, d spacing (101) of anatase's lattice shifted to the right, and the degree of tetragonality increased to 2.53. Raman results showed that the most intense band of Eg mode for doped samples TiO2 was shifted from 144 to 152 cm – 1 compared to anatase dependence on the noble metal concentration. The features of the silver-ceria and silver – titania interactions are connected with the size effects of both Ag and CeO2 particles, concentrations of oxygen vacancies in the ceria structure, and possible redox properties due to the interplay between Ag+/Ag0 and Ce3+/Ce4+ pair (PL) and a Schottky barrier between the metal and TiO2 and photoexcited electrons in the semiconductor are trapped by Ag nanoparticles. It was shown that the ternary composite TiO2 & CeO2 & Ag (2 wt. %) has improved photocatalytic activity due to the inclusion of CeO2 in the crystal lattice of anatase, which is confirmed by an increase in the degree of tetragonality of the lattice and prevention of oxidation of silver clusters on the surface of anatase under the influence of UV irradiation. These photocatalysts will be a perspective to the hydrogen synthesis technology. [ABSTRACT FROM AUTHOR]

Unhygienic use of towels can cause bacterial infections. Therefore, it is necessary to develop anti-bacterial, self-cleaning, hydrophilic towels. TiO2 photocatalyst modification with Ag nanoparticles can add these properties to towels. However, the problem is the process of reducing Ag ions, which usually uses chemical reducing agents that are dangerous, toxic, and expensive. This study aims to utilize gambir leaf extract as an alternative reducing agent so that Ag/TiO2 synthesis can be carried out using a green process. The results of field emission scanning electron microscopy characterization showed that the use of gambier leaf extract as a reducing agent did not cause aggregation or agglomeration. Ultraviolet-visible diffuse reflectance spectroscopy analysis showed that the bandgap energy of Ag/TiO2 prepared using gambir leaf extract as the reducing agent was only slightly higher than that of its counterpart. Fourier transform infrared spectroscopy characterization showed an increase in the number of OH groups on the Ag/TiO2 towels compared to the blank towels. This proves that Ag/TiO2 towels have superior hydrophilic properties. The results of the anti-bacterial, self-cleaning, and hydrophilic tests showed that the optimal Ag loading in various tests was 3%, which could disinfect up to 33% of the bacteria and possessed the best self-cleaning, absorption capacity, and drying rates. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Hebei University of Science & Technology is the property of Hebei University of Science & Technology, Journal of Hebei University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Antibiotic resistance is one of the biggest public health problems of our time. The nanoparticles are a powerful alternative to these antibiotics. Engineered nanoparticles show toxic effects on bacteria by different mechanisms. The bacteria–cell interaction of engineered nanoparticles exerts their toxic effects through changes in cell wall, cell membrane, and cytoplasm content/density. Thus, death occurs as a result of cell deformation. In this study, the cellular damage of silver nanoparticles, which are known to have strong antibacterial properties, and zirconium oxide and silicon oxide engineering nanoparticles, which are less known, on periodontopathic (Prevotella intermedia and Aggregatibacter actinomycetemcomitans) bacteria, were investigated by ultrastructural changes. The lysis of the cytoplasm and separation of the membrane cytoplasm were observed. Both types of bacteria treated with Ag ENP show more hollow cytoplasm than bacteria treated with the other two nanoparticles.

Infection after surgery is one of the common and most challenging clinical problems, and the development of new antibacterial coating is an effective strategy to solve this problem, which has important scientific and social significance. A bioactive coating with antibacterial function was prepared on the surface of a 3D printed porous titanium bone scaffold. It is discovered that silver (Ag) exists in the coating as a simple substance. As the Ag content increases (0%, 0.5%, 1%, 1.5%, mole fraction), the specific surface area of the mesoporous coating is decreased from 377.6 m2/g to 363.35 m2/g. In vitro mineralization results show that with the increase of Ag content, the apatite inducing ability is decreased slightly. At the same time, the antibacterial test demonstrates that the addition of silver markedly enhances the antibacterial performance of the scaffolds. Adding a small amount of silver (0.5%) can achieve 100% antibacterial rate. The MC3T3-E1 cells are cultured with the scaffolds for 1, 3 and 7 days, and it is found that the Ag-doped MBG coatings have good cyto-compatibility, and the addition of a small amount of silver can promote the proliferation of MC3T3-E1 cells. A simple dipping and pulling method was used to apply the Ag-doped MBG coating to the complex 3D printed titanium scaffolds with complex topological structure. The mineralization performance, bactericidal performance and cellular compatibility of the scaffold are significantly improved, providing a new idea for the further development of multifunctional bone implant scaffold.

This work describes an eco-friendly approach for the green formulation of Ag nanoparticles by Allium ampeloprasum extract, without using any toxic reducing and capping agents. The morphology, structure, and physicochemical properties were characterized by several analytical techniques such as fourier transformed infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Ultraviolet–visible spectroscopy (UV–Vis). The nanoparticles were explored biologically in the anticancer assays. Exposure of the nanoparticles samples to non-small-cell lung cancer cells resulted in cell death, which was mostly due to necrosis but slightly due to late apoptosis. The viability of malignant cell lines reduced dose-dependently in the presence of nanoparticles. The IC50 of nanoparticles were 301, 266, 255, and 250 µg/mL against EKVX, HOP-62, A549 and NCI-H460 cancer cell lines, respectively. The green-synthesized nanoparticles induced cell death, suggesting anticancer prospects that may offer new insight into the development of an anticancer nanomedicine.

Organ initiation from the shoot apical meristem first gives rise to leaves during vegetative development and then flowers during reproductive development. LEAFY (LFY) is activated after floral induction and together with other factors promotes the floral program. LFY functions redundantly with APETALA1 (AP1) to activate the class B genes APETALA3 (AP3) and PISTILLATA (PI), the class C gene AGAMOUS (AG), and the class E gene SEPALLATA3, which leads to the specification of stamens and carpels, the reproductive organs of flowers. Molecular and genetic networks that control the activation of AP3, PI, and AG in flowers have been well studied; however, much less is known about how these genes are repressed in leaves and how their repression is lifted in flowers. Here, we showed that two genes encoding Arabidopsis C2H2 ZINC FINGER PROTEIN (ZFP) transcription factors, ZP1 and ZFP8, act redundantly to directly repress AP3, PI, and AG in leaves. After LFY and AP1 are activated in floral meristems, they down-regulate ZP1 and ZFP8 directly to lift the repression on AP3, PI, and AG. Our results reveal a mechanism for how floral homeotic genes are repressed and derepressed before and after floral induction. [ABSTRACT FROM AUTHOR]

In this work, we reported the spontaneous growth of Ag and Au microstructures on the surface of the graphene oxide‐grafted‐polystyrene sulfonic acid brushes (GO‐g‐PSSA) in Ag(NH3)2OH solution and HAuCl4 solution, respectively. The influences of reaction time and temperature on the morphology and size of Ag (Au) particles were investigated. By optimizing reaction conditions, Ag nanosheet‐assembled microstructures and sea urchin‐like Au microspheres were obtained. These hierarchical Ag (Au) microstructures with highly nanotextured topographies could provide many "hot spots" for surface‐enhanced Raman spectroscopy (SERS). The as‐prepared GO‐g‐PSSA/Ag (Au) composites exhibited excellent SERS performances using Rhodamine 6G (R6G) as the probe molecules and the detection limit of R6G was up to 10−12 m. [ABSTRACT FROM AUTHOR]

Since printed capacitive sensors provide better sensing performance, they can be used in automotive bezel applications. It is necessary to fabricate such sensors and apply an optimization approach for choosing the optimal sensor pattern. In the present work, an effort was made to formulate interdigitated pattern-printed Silver (Ag) electrode flexible sensors and adopt the Taguchi Grey Relational (TGR)-based optimization approach to enhance the flexible sensor's panel for enhanced automobile infotainment applications. The optimization technique was performed to derive better design considerations and analyze the influence of the sensor's parameters on change in capacitance when touched and production cost. The fabricated flexible printed sensors can provide better sensing properties. A design pattern which integrates an overlap of 15 mm, an electrode line width of 0.8 mm, and an electrode gap 0.8 mm can produce a higher change in capacitance and achieve a lower weight. The overlap has a greater influence on sensor performance owing to its optimization of spatial interpolation. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here, we describe the recent progress on metal‐coordinated supramolecular structures with unique characteristics and controlled helicity based on coordination geometry and dynamic intermolecular binding events. The current major research area is the self‐assembly of a metal‐containing molecule into nanomaterials. It generated a large number of supramolecular polymers, which have various structures and functions. Although the dynamic coordination complexation reactions between various metal ions and ligands are spontaneous, we successfully achieved unique morphological transformations with helical inversion of metal‐containing supramolecular polymers via the kinetic control of dynamic coordination complexation reactions. Our findings have a significant impact on the development of novel and advanced supramolecular materials, and dynamic coordination bonds in the molecular design of metal‐containing complexes for modulating self‐assembly pathways, which may be relevant for the fabrication of supramolecular materials with interesting properties. Our contributions may be useful to the understanding of chiral assembly processes in biological systems. [ABSTRACT FROM AUTHOR]

Green nanotechnology has made the synthesis of nanoparticles a possible approach. Nanotechnology has a significant impact on several scientific domains and has diverse applications in different commercial areas. The current study aimed to develop a novel and green approach for the biosynthesis of silver oxide nanoparticles (Ag2ONPs) utilizing Parieteria alsinaefolia leaves extract as a reducing, stabilizing and capping agent. The change in color of the reaction mixture from light brown to reddish black determines the synthesis of Ag2ONPs. Further, different techniques were used to confirm the synthesis of Ag2ONPs, including UV-Visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), zeta potential and dynamic light scattering (DLS) analyses. The Scherrer equation determined a mean crystallite size of ~22.23 nm for Ag2ONPs. Additionally, different in vitro biological activities have been investigated and determined significant therapeutic potentials. Radical scavenging DPPH assay (79.4%), reducing power assay (62.68 ± 1.77%) and total antioxidant capacity (87.5 ± 4.8%) were evaluated to assess the antioxidative potential of Ag2ONPs. The disc diffusion method was adopted to evaluate the antibacterial and antifungal potentials of Ag2ONPs using different concentrations (125–1000 μg/mL). Moreover, the brine shrimp cytotoxicity assay was investigated and the LC50 value was calculated as 2.21 μg/mL. The biocompatibility assay using red blood cells (<200 μg/mL) confirmed the biosafe and biocompatible nature of Ag2ONPs. Alpha-amylase inhibition assay was performed and reported 66% inhibition. In conclusion, currently synthesized Ag2ONPs have exhibited strong biological potential and proved as an attractive eco-friendly candidate. In the future, this preliminary research work will be a helpful source and will open new avenues in diverse fields, including the pharmaceutical, biomedical and pharmacological sectors. [ABSTRACT FROM AUTHOR]

This study aims to examine the impact of the direct and indirect mixing techniques on the dispersion and homogeneity of magnesium oxide (MgO) and silver (Ag) nanoparticles (NPs) mixed with polymethylmethacrylate (PMMA). NPs were mixed with PMMA powder directly (non-ethanol-assisted) and indirectly (ethanol-assisted) with the aid of ethanol as solvent. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscope (SEM) were used to evaluate the dispersion and homogeneity of MgO and Ag NPs within the PMMA-NPs nanocomposite matrix. Prepared discs of PMMA-MgO and PMMA-Ag nanocomposite were analyzed for dispersion and agglomeration by Stereo microscope. XRD showed that the average crystallite size of NPs within PMMA-NP nanocomposite powder was smaller in the case of ethanol-assisted mixing compared to non-ethanol-assisted mixing. Furthermore, EDX and SEM revealed good dispersion and homogeneity of both NPs on PMMA particles with ethanol-assisted mixing compared to the non-ethanol-assisted one. Again, the PMMA-MgO and PMMA-Ag nanocomposite discs were found to have better dispersion and no agglomeration with ethanol-assisted mixing when compared to the non-ethanol-assisted mixing technique. Ethanol-assisted mixing of MgO and Ag NPs with PMMA powder obtained better dispersion, better homogeneity, and no agglomeration of NPs within the PMMA-NP matrix. [ABSTRACT FROM AUTHOR]

One of the crucial challenges of our time is to effectively use metal and metal oxide nanoparticles (NPs) as an alternative way to combat drug-resistant infections. Metal and metal oxide NPs such as Ag, Ag2O, Cu, Cu2O, CuO, and ZnO have found their way against antimicrobial resistance. However, they also suffer from several limitations ranging from toxicity issues to resistance mechanisms by complex structures of bacterial communities, so-called biofilms. In this regard, scientists are urgently looking for convenient approaches to develop heterostructure synergistic nanocomposites which could overcome toxicity issues, enhance antimicrobial activity, improve thermal and mechanical stability, and increase shelf life. These nanocomposites provide a controlled release of bioactive substances into the surrounding medium, are cost effective, reproducible, and scalable for real life applications such as food additives, nanoantimicrobial coating in food technology, food preservation, optical limiters, the bio medical field, and wastewater treatment application. Naturally abundant and non-toxic Montmorillonite (MMT) is a novel support to accommodate NPs, due to its negative surface charge and control release of NPs and ions. At the time of this review, around 250 articles have been published focusing on the incorporation of Ag-, Cu-, and ZnO-based NPs into MMT support and thus furthering their introduction into polymer matrix composites dominantly used for antimicrobial application. Therefore, it is highly relevant to report a comprehensive review of Ag-, Cu-, and ZnO-modified MMT. This review provides a comprehensive overview of MMT-based nanoantimicrobials, particularly dealing with preparation methods, materials characterization, and mechanisms of action, antimicrobial activity on different bacterial strains, real life applications, and environmental and toxicity issues. [ABSTRACT FROM AUTHOR]

An enhancement of the local electric field at the metal/dielectric interface of hybrid materials due to the localized surface plasmon resonance (LSPR) phenomenon plays a particularly important role in versatile research fields resulting in a distinct modification of the electrical, as well as optical, properties of the hybrid material. In this paper, we succeeded in visually confirming the LSPR phenomenon in the crystalline tris(8-hydroxyquinoline) aluminum (Alq3) micro-rod (MR) hybridized with silver (Ag) nanowire (NW) in the form of photoluminescence (PL) characteristics. Crystalline Alq3 MRs were prepared by a self-assembly method under the mixed solution of protic and aprotic polar solvents, which could be easily applied to fabricate hybrid Alq3/Ag structures. The hybridization between the crystalline Alq3 MRs and Ag NWs was confirmed by the component analysis of the selected area electronic diffraction attached to high-resolution transmission electron microscope. Nanoscale and solid state PL experiments on the hybrid Alq3/Ag structures using a lab-made laser confocal microscope exhibited a distinct enhancement of the PL intensity (approximately 26-fold), which also supported the LSPR effects between crystalline Alq3 MRs and Ag NWs. [ABSTRACT FROM AUTHOR]

Using thermal evaporation, thin films of silver-doped CdSe were synthesized on glass bases. A hexagonal structure with a preference orientation along (100) plane according to the X-ray diffraction pattern. The surface topography was determined using Atomic Force Microscopy (AFM). AFM detects spherical nature nanoparticles and roughness rate of the CdSe thin film decreases and the root mean square decreases with (2 and 4) % doping in silver. As the doping content increase, the optical energy bandgap decrease from 1.85 eV to 1.75 eV. Optical analysis indicates that Ag doping in CdSe results in a redshift in band edge. [ABSTRACT FROM AUTHOR]

The wetting behavior of ionic liquids (ILs) on the mesoscopic scale considerably impacts a wide range of scientific fields and technologies. Particularly under vacuum conditions, these materials exhibit unique characteristics. This work explores the effect of the deposition rate and substrate temperature on the nucleation, droplet formation, and droplet spreading of ILs films obtained by thermal evaporation. Four ILs were studied, encompassing an alkylimidazolium cation (CnC1im) and either bis(trifluoromethylsulfonyl)imide (NTf2) or the triflate (OTf) as the anion. Each IL sample was simultaneously deposited on surfaces of indium tin oxide (ITO) and silver (Ag). The mass flow rate was reproducibly controlled using a Knudsen cell as an evaporation source, and the film morphology (micro- and nanodroplets) was evaluated by scanning electron microscopy (SEM). The wettability of the substrates by the ILs was notably affected by changes in mass flow rate and substrate temperature. Specifically, the results indicated that an increase in the deposition rate and/or substrate temperature intensified the droplet coalescence of [C2C1im][NTf2] and [C2C1im][OTf] on ITO surfaces. Conversely, a smaller impact was observed on the Ag surface due to the strong adhesion between the ILs and the metallic film. Furthermore, modifying the deposition parameters resulted in a noticeable differentiation in the droplet morphology obtained for [C8C1im][NTf2] and [C8C1im][OTf]. Nevertheless, droplets from long-chain ILs deposited on ITO surfaces showed intensified coalescence, regardless of the deposition rate or substrate temperature. [ABSTRACT FROM AUTHOR]

In this work, CeO2 nanoparticles, as well as CeO2 nanocomposites with plasmonic silver nanoparticles, were synthesized using a simple sol-gel process. The concentration of silver in the composites varied from 0.031–0.25 wt%. Cerium hydroxide dried gel was calcined at temperatures from 125 to 800 °C to obtain CeO2. It was shown that, at an annealing temperature of 650 °C, single-phase CeO2 nanopowders with an average particle size in the range of 10–20 nm can be obtained. The study of acid-base properties showed that with an increase in the calcination temperature from 500 to 650 °C, the concentration of active centers with pKa 9.4 and 6.4 sharply increases. An analysis of the acid-base properties of CeO2-Ag nanocomposites showed that with an increase in the silver concentration, the concentration of centers with pKa 4.1 decreases, and the number of active centers with pKa 7.4 increases. In a model experiment on dye photodegradation, it was shown that the resulting CeO2 and CeO2-Ag nanopowders have photocatalytic activity. CeO2-Ag nanocomposites, regardless of the silver concentration, demonstrated better photocatalytic activity than pure nanosized CeO2. [ABSTRACT FROM AUTHOR]

Recent years have seen much attention being given to self-assembly of dipeptide-based structures, especially to self-regulation of dipeptide structures with different amino acid sequences. In this study we investigated the effects of varying solvent environments on the self-assembly of glycine-histidine (Gly-His) dipeptide structures. First we determined the morphological properties of Gly-His films formed in different solvent environments with scanning electron microscopy and then structural properties with Fourier-transform infrared (FTIR) spectroscopy. In addition, we studied the effects of Gly-His films on silver nanoparticle (AgNP) formation and the antioxidant and cytotoxic properties of AgNPs obtained in this way. We also, assessed antibacterial activities of Gly-His films against Gram-negative Escherichia coli and Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus. Silver nanoparticle-decorated Gly-His films were not significantly cytotoxic at concentrations below 2 mg/mL but had antibacterial activity. We therefore believe that AgNP-decorated Gly-His films at concentrations below 2 mg/mL can be used safely against bacteria.

• As 10 Ge 30 S 60 film with a thickness of ∼13 nm has a granular structure. • Thermal diffusion coefficient of Ag into GeSe 2 film is several times higher than into As 10 Ge 30 S 60. • SPP excitation leads to a triple increase in the photostimulated Ag flux into the As 10 Ge 30 S 60 layer. • Thermo- and photodoped with silver As 10 Ge 30 S 60 layers have different optical properties. This study examines the kinetics of thermal diffusion of silver in Ag-GeSe 2 and Ag- As 10 Ge 30 S 60 thin film structures during prolonged storage in the dark at room temperature, as well as the effects of plasmon-enhanced photostimulated diffusion of silver into As 10 Ge 30 S 60 films. Ag diffraction gratings with a period of 519 nm were used to excite surface plasmon-polaritons (SPP) at the silver-chalcogenide glass interface. It was found that the thermal diffusion coefficient of silver into GeSe 2 is significantly higher than into As 10 Ge 30 S 60. For Ag– As 10 Ge 30 S 60 , photostimulated silver diffusion coefficients were measured with and without SPP excitation. SPP excitation triples the photostimulated Ag flux into As 10 Ge 30 S 60. Although photosensitivity decreases over time, the plasmon-stimulated increase in Ag flux remains stable. Additionally, As 10 Ge 30 S 60 thermally doped with silver shows much higher optical absorption at the probing wavelength compared to the photodoped layer with the same silver concentration. Possible mechanisms of these layers formation are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effects of different support types on the NH 3 -SCO performance of Ag-based catalysts were analyzed. • The interaction mechanism between support physicochemical properties and Ag active species was revealed. • The NH 3 -SCO reaction mechanism on Ag/nano-TiO 2 catalyst was described by In-situ DRIFTS and DFT calculation. Herein, the influence of support type and properties on the catalytic activity and selectivity of Ag-based NH 3 -SCO catalyst was studied through the evaluation of NH 3 -SCO performance, the physicochemical characterization of H 2 -TPR, NH 3 -TPD, N 2 isothermal adsorption–desorption, XPR and XPS, and the mechanism study of 1H MAS NMR, In-situ DRIFTS and DFT calculations. Ag/nano-TiO 2 , Ag/Al 2 O 3 , and Ag/MnO 2 all showed better NH 3 -SCO activity because of more abundant Brønsted and Lewis acid sites of Al 2 O 3 and TiO 2 and more actual Ag loading amount due to the larger specific surface area and suitable surface chemistry. The N 2 selectivity of Ag/nano-TiO 2 is significantly better, which may be due to the highly dispersed Ag species and the abundant Brønsted acid sites with higher N 2 selectivity. The mechanism study showed that the terminal hydroxyl was the preferred consumption target of Ag species, and this consumption promoted the effective dispersion and stable anchoring of Ag on the TiO 2 surface. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ag-Al 2 O 3 - m and Ag-K-Al 2 O 3 - m were fabricated by a one-pot technique following an evaporation-induced self-assembly method. • Ag-3 K-Al 2 O 3 showed excellent catalytic performance and water-resistance for HCHO oxidation. • The high catalytic activity was due to abundant surface active oxygen species and surface –OH. • The HCHO oxidation over Ag-Al 2 O 3 - m and Ag-K-Al 2 O 3 - m followed the same mechanism. Mesoporous Ag-Al 2 O 3 - m and Ag-K-Al 2 O 3 - m catalysts were fabricated by a one-pot technique based on an evaporation-induced self-assembly method. Among them, Ag-3 K-Al 2 O 3 - m exhibited the highest activity, achieving 100 % HCHO conversion at 40 °C. The catalyst's performance was notably impacted by RH conditions, which showed improved activity at 30 % RH, due to the formation of active –OH groups. As the K loading increased, the aggregation of Ag particles gradually occurred. According to DFT computation, the presence of K promoted the adsorption and activation of HCHO, O 2 and H 2 O on the catalyst surface. The superior low-temperature reducibility, adequate surface active oxygen and surface –OH groups were identified as key roles to the enhanced catalytic performance of Ag-K-Al 2 O 3 - m. Both Ag-Al 2 O 3 - m and Ag-K-Al 2 O 3 - m operated through the same oxidation mechanism for HCHO oxidation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel TiO 2 /Ag hybrid aerogels SERS substrate was successfully prepared. • The TiO 2 /Ag hybrid aerogels SERS substrate exhibited outstanding SERS property. • The TiO 2 /Ag hybrid aerogels SERS substrate showed good reproducibility. This research focuses on preparing a series of new TiO 2 /Ag hybrid aerogels with varying TiO 2 contents, and demonstrates their application as ultrasensitive SERS substrates. The synthesized TiO 2 /Ag hybrid aerogels exhibited excellent SERS behavior when detecting 4-Mercaptobenzoic acid (4-MBA), and the calculated SERS enhancement factor (EF) was 6.34 × 106. 3D structured aerogels can create more hot spots and adsorption sites, and multiple interband chemical transfer (CT) pathways emerged and enhanced CT efficiency because of the large number of surface oxygen vacancies of meso -TiO 2 NPs. Therefore, the synergy of electromagnetic field enhancement and chemical enhancement leads to SERS enhancement. In addition, the composite SERS substrate has high sensitivity, and the detection limit of adsorbed 4-MBA probe molecules reaches 10-11 M. Furthermore, the TiO 2 /Ag hybrid aerogels demonstrate good reproducibility with minimal standard deviation in terms of SERS signals. In addition, even after standing for 6 months, there is almost no attenuation in the SERS signal intensity, which highlights the excellent stability of this substrate. Therefore, these highly sensitive TiO 2 /Ag hybrid aerogels SERS substrates have important practical value in environmental monitoring, medical inspection and food supervision. [ABSTRACT FROM AUTHOR]