Farmerhaley7028

The piezoelectricity of the biocompatible and biodegradable polymer polylactic acid (PLA) was investigated as a potential magnetoelectric (ME) nanocomposite for biomedical applications. A key focus was to quantify the piezoelectric properties of single PLA fibers while tuning their polymer degradability through the addition of faster degrading polymer, poly (DL-lactide-co-glycolide) (PLGA), which is not a piezoelectric polymer. Piezoresponse Force Microscopy (PFM) showed that electrospun PLA fibers gave a piezoelectric response of 186.0 ± 28.1 pm. For comparison both PLA/PLGA (75/25) and PLA/PLGA (50/50) fibers gave significantly lower piezoelectric responses of 88.8 ± 12.3 pm and 49.6 ± 9.1 pm, respectively. For the highest content PLGA fibers, PLA/PLGA (25/75), only very few fibers exhibited a low response of 28.8 pm while most showed no response. Overall, an increasing PLGA content caused a decrease in the piezoelectric response, thus an expected trade-off existed between the biodegradability (i.e. PLA to PLGA content ratio) versus piezoelectricity. The findings were considered significant due to the existence of piezoelectricity in a tuneable biodegradable material that has potential to impart piezoelectric induced effects on biointeractions with the surrounding biological environment or drug interactions with the polymer to control the rate of drug release. In such applications, there is an opportunity to magnetically control the piezoelectricity and henceforth PLA/CoFe2O4 ME nanocomposite fibers with 5% and 10% of CoFe2O4 nanoparticles were also investigated. 8-Bromo-cAMP molecular weight Both 5% and 10% PLA/CoFe2O4 nanocomposites gave lower piezoelectric responses compared to the PLA presumably due to the disturbance of polymer chains and dipole moments by the magnetic nanoparticles, in addition to effects from the possible inhomogeneous distribution of CoFe2O4 nanoparticles.A facile strategy was introduced for the development of pure MgO and its nanocomposites using different CeO2 contents (3% to 7%) to enhance the magnetic properties and their photocatalytic performance. Different morphologies (viz. nanoflowers and rhombohedral type nanostructures) were obtained using in-situ hydrothermal method at different concentrations of CeO2. X-ray diffraction results revealed that peaks of CeO2 were observed along with peaks of MgO which confirms the presence of both the phases. Crystallite size and particle size were found to increase with changing CeO2 content in host matrix of MgO. Moreover, the band gap reduces while magnetic character increases with CeO2 concentration. Magnetic behaviour of nanocomposites was elucidated on the basis of oxygen intrinsic defects which are persistent through XPS. EPR measurement was carried to understand the valance electron and favours the defects present in the material which is related with size of the nanostructures. Degradation of Rose Bengal dye was accomplished to probe the photocatalytic activity of MgO@CeO2 nanocomposites. Hence facial synthesis of these nanostructures conveyed good magnetic properties along with its application towards dye degradation.Herein, the desorption effect of supercritical CO2 (scCO2) was utilized to obtain sub-5 nm Ag NPs with the high Ag loading in the SBA-15. The Ag nanoparticles (NPs) size was decreased from 3.54 ± 0.79 nm (Ag loading 25.3 wt.% wt.%) to 2.38 ± 0.68 (Ag loading 10.5 wt.%) nm by changing depressurization curve from 0.1 MPa/min (20-14 MPa) to 3 MPa/min (20-12 MPa). Meanwhile, the intensity of crystalline Ag characteristic peaks was obviously higher than the latter sample from the x-ray diffraction (XRD) patterns. However, compared with the adsorption kinetics of two precursors of AgNO3 and Cu(NO3)2 on SBA-15, under the same deposition and depressurization conditions, when the two depositional systems used water as co-solvent, and the time reaching adsorption equilibrium of Ag+ on supports was longer than the time of Cu2+, which existed in the water as [Cu(H2O)4]2+. The surface of SBA-15 was hydrophilic, and then the interaction of Ag+ and the surface was weaker compared with Cu2+, making Ag+ highly dispersed on the surface under scCO2 desorption effect. After calcination, Ag NPs size was decreased, but the morphology of CuO was mainly characterized by nanorods (NRs). Moreover, by compared experiments of wetness impregnation, the dispersion ability of bulk scCO2 of the reactor was inefficient for Ag+ adsorbed on the channels in the depressurization process.Composites of nanostructured porous silicon and silver (nPSi-Ag) have attracted great attention due to the wide spectrum of applications in fields such as microelectronics, photonics, photocatalysis and bioengineering, Among the different methods for the fabrication of nanostructured composite materials, dip and spin-coating are simple, versatile, and cost-effective bottom-up technologies to provide functional coatings. In that sense, we aimed at fabricating nPSi-Ag composite layers. Using nPSi layers with pore diameter of 30 nm, two types of thin-film techniques were systematically compared cyclic dip-coating (CDC) and cyclic spin-coating (CSC). CDC technique formed a mix of granular and flake-like structures of metallic Ag, and CSC method favored the synthesis of flake-like structures with Ag and Ag2O phases. Flakes obtained by CDC and CSC presented a width of 110 nm and 70 nm, respectively. Particles also showed a nanostructure surface with features around 25 nm. According to the results of EDX and RBS, integration of Ag into nPSi was better achieved using the CDC technique. SERS peaks related to chitosan adsorbed on Ag nanostructures were enhanced, especially in the nPSi-Ag composite layers fabricated by CSC compared to CDC, which was confirmed by FTDT simulations. These results show that CDC and CSC produce different nPSi-Ag composite layers for potential applications in bioengineering and photonics.Motivation and objectiveFor each institute, the selection and calibration of the most suitable approach to assign material properties for Monte Carlo (MC) patient simulation in proton therapy is a major challenge. Current conventional approaches based on computed tomography (CT) depend on CT acquisition and reconstruction settings. This study proposes a material assignment approach, referred to as MATA (MATerialAssignment), which is independent of CT scanner properties and, therefore, universally applicable by any institute.Materials and methodsThe MATA approach assigns material properties to the physical quantity stopping-power ratio (SPR) using a set of 40 material compositions specified for human tissues and linearly determined mass density. The application of clinically available CT-number-to-SPR conversion avoids the need for any further calibration. The MATA approach was validated with homogeneous and heterogeneous SPR datasets by assessing the SPR accuracy after material assignment obtained either based on dose scoring or determination of water-equivalent thickness.