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In this research, the fabrication of silver nanoparticles and experimental nonlinear response (NLO). The fabrication of the silver nanoparticles has been done using E-Beam evaporation on a glass substrate (Ag-NPs) and investigation of their nonlinear optical response (NLO). The silver nanoparticles was evaluated by optical spectrum (UV-Vis) that shows localized surface Plasmon band at 375 nm. The experiment shows the nonlinear absorption and nonlinear refraction effect of silver nanoparticles, the silver nanoparticles is analysed by Z-Scan technique using a femtoseconds laser with 800 nm wavelength. The result shows the nonlinear absorption (NLA) is at 4.87×10−4cmW−1, while (NLR) is at 7.94×10−9cm2W−1.

Metal surfaces exposed to air environments invariably undergo various surface modifications, altering their secondary electron emission coefficient (SEEC). However, the physical mechanisms underlying these surface modifications differ across metals, yielding distinct effects on SEEC. To investigate the SEEC properties of silver oxide and the impact of surface oxidation on the SEEC of silver, silver oxide and silver coatings were prepared by sputtering, followed by studies of their physical properties and SEEC. Results indicate that under conditions where preparation, storage, and testing were kept as consistent as possible, the SEEC of oxidized silver surfaces is not much different from that of silver-coated surfaces. The SEEC maximum values of silver oxide and silver coatings are 1.7 and 1.6, and the values decreased to 1.5 and 1.4 after ion-sputtering treatment. To validate the impact of surface oxidation on the SEEC of silver, various surface states were achieved on silver substrates. Elemental analysis revealed that vacuum heating effectively removes contaminants from silver coating surfaces, resulting in a significant reduction in SEEC values. Ion sputtering removed contaminants, etched the oxidation layer, and modified the morphology of the silver surface effectively. After 5 min of ion sputtering, the SEEC maximum of the original silver sample decreased from 2.6 to 1.73, and after 15 min of ion sputtering, it further decreased to 1.7. This result indicates that surface oxidation contributes minimally to the SEEC variation of silver exposed to air. The findings revealed in this work hold engineering significance for understanding alterations in the SEEC properties of silver surfaces under different surface conditions.

AimProsthetic joint infection (PJI) is a common complication following orthopedic megaprosthetic implantations (EPR), estimated up to 50%. Silver coatings were introduced in order to reduce the incidence of PJI, by using the antibacterial activity of silver. Three different silver coatings are available: MUTARS® (Implantcast), Agluna® (Accentus Medical), PorAg® (Waldemar Link). The aim of this review is to provide an overview on efficacy and safety of silver-coated EPR both in primary and revision surgery, comparing infection rate according to the type of implant. MethodsThrough an electronic systematic search, we reviewed the articles concerning silver-coated EPRs. Infection rate, silver-related complications, local and blood concentrations of the silver were evaluated. Meta-analyses were performed to compare results from each study included. ResultsNineteen studies were included. The overall infection rate in patients with silver-coated implants was 17.6% (133/755). Overall infection rate in primary silver-coated EPR was been 9.2% (44/445), compared to 11.2% (57/507) of non-silver-coated implants. The overall infection rate after revisions was 13.7% (25/183) in patients with silver-coated EPR and 29.2% (47/161) when uncoated EPR were used, revealing a strength statistically significative utility of silver coatings in preventing infections in this group (p: 0.019). Generally, the use of MUTARS® EPR had produced an almost constant decrease in the incidence of primary PJI but there are few data on the effectiveness in revisions. The results from the use of Agluna® in both primary and revisions implants are inconstant. Conversely, PorAg® had proven to be effective both in PJI prevention but, especially, when used in PJI revision settings. Local argyria was reported in 8 out of 357 patients (2.2%), while no systemic complications were described. Local and blood concentrations of silver were always reported very far to the threshold of toxicity, with the lowest concentration found using PorAg®.ConclusionsSilver-coated EPRs are safe and effective in reduction in PJI and re-infection rate, in particular when used in higher risk patients and after two-stage revisions to fight PJI.

The physical properties as well as thermal and electrical stability of copper particles can be improved by surface protection, which mainly depends on the coating material. Our study was, therefore, focused on the rheological, thermal, mechanical and electrical characterization of polymer composites by comparing uncoated (Cu), silver-coated (Cu@Ag) and silica-coated (Cu@Si) copper flakes in low-density polyethylene at various volume concentrations (up to 40%). Interactions among particles were investigated by rheological properties, as these indicate network formation (geometrical entanglement), which is important for mechanical reinforcement as well as establishing an electric pathway (electrical percolation). The results showed that geometrical and electrical percolation were the same for Cu and Cu@Si, ~15%, while, surprisingly, Cu@Ag exhibited much lower percolation, ~7.5%, indicating the fusion of the Ag coating material, which also decreased crystal growth (degree of crystallinity). Furthermore, the magnitude of the rheological and mechanical response remained the same for all investigated materials, indicating that the coating materials do not provide any load transfer capabilities. However, they profoundly affect electron transfer, in that, Cu@Ag exhibited superior conductivity (74.4 S/m) compared to Cu (1.7 × 10−4 S/m) and Cu@Si (1.5 × 10−10 S/m). The results obtained are important for the design of advanced polymer composites for various applications, particularly in electronics where enhanced electrical conductivity is desired.

The objective of this study is to investigate the feasibility of machining micro-holes on the non-conductive Aluminum Nitride (AlN) ceramics using micro-electro-discharge machining (EDM) process by exploiting various coating techniques. Although ceramics possess excellent mechanical properties under compressive load condition and superior thermal properties, machining of microscale features on ceramics remains challenging due to the extreme brittleness associated with ceramics. Due to the involvement of higher cutting force and tool wear issue, conventional machining process appears to be unsuitable for machining ceramics. On the other hand, non-contact and negligible process force associated with EDM process makes it one of the competitive processes for machining of ceramics. A series of experiments were carried out on AlN ceramics using “Assistive Electrode” micro-EDM process with a goal of machining blind micro-holes into the ceramics with the aid of on-machine fabricated copper tungsten tools. It was found that multi-layer coatings of silver and copper with copper tungsten electrode resulted in successful machining with high-aspect-ratio holes during powder mixed micro-EDM of AlN ceramics, while micro-holes with less than one aspect ratio are machined without powder addition to the dielectric. It was also observed that comparatively lower level of discharge energies, i.e., lower value of voltages and capacitances were favorable for successful machining of micro-holes in ceramics, even though it results in significantly higher machining time. Despite of relatively low discharge energy usage in micro-EDM, machined surfaces appear to be very rough. The machined surfaces indicate that melting and evaporation, as well as thermal spalling, are the dominating material removal mechanisms. The machined surfaces contained many thermal cracks and porosity on the surface. The elemental composition analysis confirms the presence of aluminum and nitrogen elements on the machined surface. Finally, by careful selection of machining conditions and assistive electrode, successful machining of micro-holes is possible on the non-conductive ceramic surfaces using the micro-EDM process.

In this paper, a microwave cavity resonator is presented for chemical sensing applications. The proposed resonator is comprised of a three dimensional (3D) split-ring resonator (SRR) residing in an external cavity and capacitively coupled by a pair of coaxial probes. 3D-printing technology with polylactic acid (PLA) filament is used to build the 3D SRR and cavity. Then, the surfaces of the SRR and the inside walls of cavity are silver-coated. The novelty of our proposed structure is its light weight and inexpensive design, owing to the utilization of low density and low-cost PLA. A Teflon tube is passed through the split-gap of the SRR so that it is parallel to the applied electric field. With an empty tube, the resonance frequency of the structure is measured at 2.56 GHz with an insertion loss of 13.6 dB and quality factor (Q) of 75. A frequency shift of 205 MHz with respect to the empty channel was measured when deionized water (DIW) was injected into the tube. Using volume occupied by the structure, the weight of the proposed microwave resonator is estimated as 22.8 g which is significantly lighter than any metallic structure of comparable size.

In recent years, antibacterial coatings have become an important approach in the global fight against bacterial pathogens. Developments in materials science, chemistry, and biochemistry have led to a plethora of materials and chemical compounds that have the potential to create antibacterial coatings. However, insufficient attention has been paid to the analysis of the techniques and technologies used to apply these coatings. Among the various inorganic coating techniques, atomic layer deposition (ALD) is worthy of note. It enables the successful synthesis of high-purity inorganic nanocoatings on surfaces of complex shape and topography, while also providing precise control over their thickness and composition. ALD has various industrial applications, but its practical application in medicine is still limited. In recent years, a considerable number of papers have been published on the proposed use of thin films and coatings produced via ALD in medicine, notably those with antibacterial properties. The aim of this paper is to carefully evaluate and analyze the relevant literature on this topic. Simple oxide coatings, including TiO2, ZnO, Fe2O3, MgO, and ZrO2, were examined, as well as coatings containing metal nanoparticles such as Ag, Cu, Pt, and Au, and mixed systems such as TiO2-ZnO, TiO2-ZrO2, ZnO-Al2O3, TiO2-Ag, and ZnO-Ag. Through comparative analysis, we have been able to draw conclusions on the effectiveness of various antibacterial coatings of different compositions, including key characteristics such as thickness, morphology, and crystal structure. The use of ALD in the development of antibacterial coatings for various applications was analyzed. Furthermore, assumptions were made about the most promising areas of development. The final section provides a comparison of different coatings, as well as the advantages, disadvantages, and prospects of using ALD for the industrial production of antibacterial coatings.

Silver (Ag) possesses potent antimicrobial properties and is used as a coating for medical devices. The impact of silver ions released from orthopedic implants on the differentiation and osteoid formation of different osteogenic cells has yet to be systematically studied. In the present study, human mesenchymal stem cells (hMSCs) and primary human osteoblasts (hOBs) were exposed to different static Ag+ concentrations (0, 0.5, 1.0 or 1.5 ppm) or dynamic Ag+ concentrations (range 0 to 0.7 ppm) that simulated the temporal release pattern from a Ag-nitrate coating of trabecular titanium (TLSN). Cell morphology was investigated by phase contrast and fluorescence microscopy. The activities of alkaline phosphatase (ALP) and lactate dehydrogenase, osteogenic gene expression (COL1A1, COL1A2 and ALPL), and osteoid deposition were examined for up to 4 weeks. DAPI and carboxyfluorescein diacetate staining revealed changes in the morphology of hOBs treated with ≥0.5 ppm Ag+, while osteocalcin-positive cells were observed primarily in the untreated group. Elevated Ag+ concentrations did not impact the production of ALP by either hMSCs or hOBs. Treatment with 1.5 ppm Ag+ or TLSN Ag+ led to a modest reduction in COL1A2 and ALPL levels in hMSCs at 2 weeks but not at 4 weeks nor in hOBs. In hMSC cultures, mineralization decreased at ≥1 ppm Ag+, whereas the same concentration range significantly reduced mineralization in hOB cultures. In conclusion, Ag+ concentrations ranging from 1.0 to 1.5 ppm may interfere with osteogenic differentiation, possibly by altering gene expression, thereby affecting mineralization. Only Ag+ concentrations up to 0.5 ppm allowed undisturbed osteogenic differentiation and mineralization. These findings pertain to creating Ag coatings of titanium intended for cementless fixation into host bone.

Smart textile with IR radiative cooling is of paramount importance for reducing energy consumption and improving the thermal comfort of individuals. However, wearable textile via facile methods for indoor/outdoor thermal management is still challenging. Here we present a novel simple, yet effective method for versatile thermal management via silver-coated polyamide (PA) textile. Infrared transmittance of coated fabric is greatly enhanced by 150% due to the multi-order reflection of silver coating. Based on their IR radiative cooling, indoors and outdoors, the skin surface temperature is lower by 1.1 and 0.9 °C than normal PA cloth, allowing the textile to be used in multiple environments. Moreover, the coated fabric is capable of active warming up under low voltage, which can be used in low-temperature conditions. These promising results exemplify the practicability of using silver-coated textile as a personal thermal management cloth in versatile environments.

IntroductionWe aim to evaluate the use of silver (PorAg®) coated compared to uncoated prosthesis in two-stage revision for prosthetic joint infection (PJI) of distal femur and proximal tibia megaprosthesis in oncological patients.Materials and methodsIn total, 68 patients were retrospectively evaluated. Median age was 30 years (range 14–83). In total, 29 patients were re-implanted with PorAg® prosthesis and 39 with uncoated prosthesis (Megasystem C®, Waldemar Link GmbH & Co. KG, Hamburg, Germany). All patients had PJI confirmed according to Musculoskeletal Infection Society (MSIS) criteria. In 10 cases, no microorganism was identified at the time of first-stage revision, but all had a sinus communicating with the prosthesis.Successful eradication of the infection was defined by the absence of clinical/serologic evidence of infection at 6 months after the second stage or at latest follow-up. Infection was again defined according to the MSIS criteria.ResultsAt 3-year follow-up, estimated reinfection rate in the silver group was slightly lower than in uncoated EPR (10.3% vs. 17.5%, p = 0.104). Among reinfected patients, only one out of three patients (33%) in the silver group required an amputation compared to 80% in the nonsilver group (p = 0.047).ConclusionsOur results show the efficacy of PorAg® coating in the two-stage revision of knee EPR. PorAg®-coated EPR may have possible advantages over this traditional strategy, in particular when applied to patients with a higher risk of reinfection.