Efficacy of mycosynthesised AgNPs from Earliella scabrosa as an in vitro antibacterial and wound healing agent

The silver nanoparticles (AgNPs) with their unique chemical and physical properties are proving as a new therapeutical agent. In the present study, the AgNPs synthesised from an aqueous extract of a macrofungus, Earliella scabrosa, were characterised by field emission scanning electron microscopy (FESEM), energy dispersive X‐ray analysis (EDX), high‐resolution transmission electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and further evaluate for its in vitro antibacterial and wound healing efficacy. The mycosynthesised AgNPs exhibited the surface plasmon resonance peak at 410 nm with good stability over a period of a month. The FESEM and EDX analyses revealed the spherical‐shaped AgNPs of an average size of 20 nm and the presence of elemental Ag, respectively. The XRD pattern showed the crystalline nature of AgNPs. The FTIR spectra confirmed the conversion of Ag⁺ ions to AgNPs due to reduction by biomolecules of macrofungus extract. The mycosynthesised AgNPs showed effective antibacterial activity against two Gram‐positive bacteria, namely Bacillus subtilis and Staphylococcus aureus, and two Gram‐negative bacteria Escherichia coli and Pseudomonas aeruginosa. The pathogens were highly sensitive to AgNPs, whereas less sensitive to AgNO₃. The mycosynthesised AgNPs showed significant wound healing potential with 68.58% of wound closure.Inspec keywords: surface plasmon resonance, wounds, X‐ray diffraction, nanoparticles, molecular biophysics, nanomedicine, antibacterial activity, biomedical materials, reduction (chemical), silver, microorganisms, X‐ray chemical analysis, nanofabrication, transmission electron microscopy, particle size, field emission scanning electron microscopy, Fourier transform infrared spectraOther keywords: high‐resolution transmission electron microscopy, healing efficacy, mycosynthesised AgNPs, spherical‐shaped AgNPs, wound healing agent, in vitro antibacterial efficacy, Earliella scabrosa, silver nanoparticles, physical properties, chemical properties, therapeutical agent, aqueous extract, macrofungus, field emission scanning electron microscopy, FESEM, energy dispersive X‐ray analysis, EDX, X‐ray diffraction, XRD, Fourier transform infrared spectroscopy, FTIR spectroscopy, surface plasmon resonance peak, crystalline nature, biomolecules, Gram‐positive bacteria, Bacillus subtilis, Staphylococcus aureus, Gram‐negative bacteria, Escherichia coli, Pseudomonas aeruginosa, pathogens, wound closure, Ag     

Monitoring of hard turning using acoustic emission signal

Monitoring of tool wear during hard turning is essential. Many investigators have analyzed the acoustic emission (AE) signals generated during machining to understand the metal cutting process and for monitoring tool wear and failure. In the current study on hard turning, the skew and kurtosis parameters of the root mean square values of AE signal (AERMS) are used to monitor tool wear. The rubbing between the tool and the workpiece increases as the tool wear crosses a threshold, thereby shifting the mass of AERMS distribution to right, leading to a negative skew. The increased rubbing also led to a high kurtosis value in the AERMS distribution curve.     

High Temperature Phase Stability and Microstructural Characterization of D9 Stainless Steel-Zirconium Metal Waste Form Alloys

Zirconium present in stainless steel-zirconium metal waste form (MWF) alloys form Ni?CZr and Fe?CZr intermetallic phases which act as a sink for radionuclide and improve resistance to localized corrosion as well as selective radionuclide leaching. The present study looks into the behavior of Zr intermetallics in MWF alloys with the variation of Zr content after heat treatments. Two MWF alloys of D9 SS (Ti modified 15Cr?C15Ni?C2.5Mo stainless steel) with 8.5 and 17?wt% Zr were heat treated at 1,323?K for 2 and 5?h and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The stability of the Zr intermetallic compounds was examined by high temperature XRD. The results from XRD study showed the presence of NiZr, Ni₅Zr, Ni₇Zr₂, FeZr₂, and Fe₃Zr peaks along with fcc Fe based solid solution. The MWF alloy with 17?wt% Zr exhibited ??-ferrite peak in as-cast condition which was not observed after heat treatment. From the SEM micrograph the agglomeration of intermetallic phases was observed after heat treatment and the grain size of the intermetallic phases increased with duration of heat treatment. The high temperature XRD study revealed that all the intermetallic phases were stable up to 1,173?K and above this temperature Ni?CZr intermetallics started disappearing. However Fe?CZr intermetallics were stable till 1,373?K. The paper presents the high temperature phase stability of D9 SS-Zr MWF alloys.     

Surface adsorption of poisonous Pb(II) ions from water using chitosan functionalised magnetic nanoparticles

In this study, chitosan functionalised magnetic nano‐particles (CMNP) was synthesised and utilised as an effective adsorbent for the removal of Pb(II) ions from aqueous solution. The experimental studies reveal that adsorbent material has finer adsorption capacity for the removal of heavy metal ions. Parameters affecting the adsorption of Pb(II) ions on CMNP, such as initial Pb(II) ion concentration, contact time, solution pH, adsorbent dosage and temperature were studied. The adsorption equilibrium study showed that present adsorption system followed a Freundlich isotherm model. The experimental kinetic studies on the adsorption of Pb(II) ions exhibited that present adsorption process best obeyed with pseudo‐first order kinetics. The maximum monolayer adsorption capacity of CMNP for the removal of Pb(II) ions was found to be 498.6 mg g⁻¹. The characterisation of present adsorbent material was done by FTIR, energy disperse X‐ray analysis and vibrating sample magnetometer studies. Thermodynamic parameters such as Gibbs free energy (ΔG °), enthalpy (ΔH °) and entropy (ΔS °) have declared that the adsorption process was feasible, exothermic and spontaneous in nature. Sticking probability reported that adsorption of Pb(II) ions on CMNP was favourable at lower temperature and sticking capacity of Pb(II) ions was very high.Inspec keywords: adsorption, lead, wastewater treatment, monolayers, Fourier transform infrared spectra, X‐ray chemical analysis, magnetometers, pHOther keywords: poisonous Pb(II) ions surface adsorption, chitosan functionalised magnetic nanoparticle, CMNP, Pb(II) ions removal, aqueous solution, finer adsorption capacity, heavy metal ion removal, contact time, solution pH, adsorbent dosage, adsorption equilibrium, Freundlich isotherm model, pseudofirst order kinetics, monolayer adsorption capacity, FTIR, energy disperse X‐ray analysis, vibrating sample magnetometer study, thermodynamic parameter, sticking probability, Pb(II) ions sticking capacity, initial Pb(II) ion concentration     

In vitro evaluation of biodegradable nHAP‐Chitosan‐Gelatin‐based scaffold for tissue engineering application

The present study focuses on fabrication and characterisation of porous composite scaffold containing hydroxyapatite (HAP), chitosan, and gelatin with an average pore size of 250–1010 nm for improving wound repair and regeneration by Electrospinning method. From the results of X ‐Ray Diffraction (XRD) study, the peaks correspond to crystallographic structure of HAP powder. The presence of functional group bonds of HAP powder, Chitosan and scaffold was studied using Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology of the scaffold was observed using Scanning Electron Microscope (SEM). The Bioactivity of the Nano composite scaffolds was studied using simulated body fluid solution at 37 ± 1°C. The biodegradability test was studied using Tris‐Buffer solution for the prepared nanocomposites [nano Chitosan, nano Chitosan gelatin, Nano based Hydroxyapatite Chitosan gelatin]. The cell migration and potential biocompatibility of nHAP‐chitosan‐gelatin scaffold was assessed via wound scratch assay and were compared to povedeen as control. Cytocompatibility evaluation for Vero Cells using wound scratch assay showed that the fabricated porous nanocomposite scaffold possess higher cell proliferation and growth than that of povedeen. Thus, the study showed that the developed nanocomposite scaffolds are potential candidates for regenerating damaged cell tissue in wound healing process.Inspec keywords: nanofabrication, tissue engineering, electrospinning, wounds, cellular biophysics, scanning electron microscopy, surface morphology, X‐ray diffraction, biomedical materials, nanomedicine, porosity, biodegradable materials, nanoporous materials, calcium compounds, gelatin, nanocomposites, Fourier transform infrared spectra, nanoparticles, precipitation (physical chemistry)Other keywords: average pore size, wound repair, crystallographic structure, HAP powder, functional group bonds, simulated body fluid solution, biodegradability test, Tris‐Buffer solution, cell migration, wound scratch assay, tissue engineering, electrospinning method, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, biocompatibility, cytocompatibility, porous nanocomposite scaffold, cell tissue, nHAP‐chitosan‐gelatin scaffold composites, wet chemical precipitation method, surface morphology, nanohydroxyapatite‐nanochitosan‐gelatin scaffold composites, cell proliferation, wound healing, (Ca₁₀ (PO₄)₆ (OH)₂)     

Mechanical and Thermal Properties Modeling,Sorption Characteristics of Multiscale (Multiwalled Carbon Nanotubes/Glass Fiber) Filler Reinforced Polypropylene Composites

The present work was aimed to investigate the individual and hybrid reinforcement effect of multiscale fillers [glass fibers (GF)/multiwalled carbon nanotubes (MWCNTs)] in polypropylene (PP) matrix. The MWCNT content in the hybrid composites was varied from 0.5 to 5 wt%, and glass fiber fraction was fixed as 20 wt%. The morphology of nano and hybrid composite revealed reasonable dispersion of MWCNTs and glass fibers in the matrix. At a MWCNT content of 3 wt%, the optimum tensile properties for the hybrid composites were achieved and beyond which it declined due to agglomeration effects as revealed by transmission electron microscopy. A comparative study of the experimental and predicted values of moduli of nano, micro, and hybrid composites using various micromechanical models was conducted. The simultaneous incorporation of MWCNTs and glass fibers in PP restricted the mobility of polymer chains as indicated by the increase in storage modulus and rise in glass transition temperature obtained by dynamic mechanical analysis. The differential scanning calorimetry studies indicated that the inclusion of 2 wt% of MWCNTs increased the crystallinity of PP from 58.2 to 69.1% in hybrid composites. The Avrami and Mo models were used to explore nonisothermal crystallization kinetics, and Mo model was in close agreement with the experimental results. The sorption behavior of the composites revealed that the formation of immobilized regions developed by the simultaneous inclusion of micro and nano fillers delayed the transport of the solvent. J. VINYL ADDIT. TECHNOL., 25:E94–E107, 2019. © 2019 Society of Plastics Engineers     

Green synthesis of gold nanoparticles: Its effect on cocoon and silk traits of mulberry silkworm (Bombyx mori L.)

In the present century the small particles are unique phenomenon which can be developed by bottom-up and top-down processes. These small particles may be considered as nanoparticles which help to build up a technology called nanotechnology. Nanomaterials are those materials which possess the length scales below 100 nm and quite often they make a comparison with a human hair, which is about 80,000 nm wide. We have introduced this technology, specially the green synthesis of gold (Au) nanoparticles in silkworm (Bombyx mori L.). The gold nanoparticles clearly indicate that they have a tremendous effect on enhancement of silk proteins and thus the enhancement of the cocoon weight in silkworms. Gold nanoparticles were prepared from onion, Allium cepa L. The extracted green gold nanomaterials from A. cepa were confirmed by UV-Vis spectrophotometer, XRD, FTIR, SEM, TEM and AFM. The function of green gold nanomaterials extracted from A. cepa was tested on silkworm physiology. We have used UV for judgment of the nature of particles and spectrum peak wavelength showed an absorption peak at 535 nm and indicated the wavelength of the surface plasmon resonance in gold nanoparticles (Au NPs). In blank solutions no such absorption peak was observed at 535 nm. Moreover, the gold (Au) XRD spectrum is supposed to and does demonstrate (111), (200), (220), and (311) peaks in the assortment of superimpose on the background. The process includes the (002) trace graphite peaks, where the (111) peak appears to be exceptionally sharp and strong which helps to propose that it is gold in nature. The FTIR shows that the examined particles are gold in nature. In SEM where electrons interact with atoms in the sample, producing various signals that can be detected and that hold information about the sample's surface topography and composition. The electron beam in SEM is generally scanned in a raster scan pattern, and therefore the beam's position is combined and detects the signal to produce an image. SEM can attain a resolution better than 1 nanometer size. The transmission electron microscope helps to accelerate the electrons as a source of elucidation. The AFM measurement is made in three dimensions process and thus it may be measured as horizontal to X-Y plane. Therefore, decree (magnification) measured at Z–direction, which is normally higher than X-Y. The said repulsive force is major one in AFM. Thus the tip and sample may considered to be the specific force in AFM which may measured at Z–direction. The effect of green gold nanoparticles on mulberry silkworm (Bombyx mori L) can exaggerated the silkworm physiological function. Larvae at 50, 100, 200, and 300 ppm doses were studied right from 1st stage to 5th instar stage. Gold nano treatment resulted in significant alterations in the percentage of fibroin and sericin proteins in the 5th instar as compared to that of control. At a 300 ppm dose of green nano gold the percentage of fibroin was 78.07, while sericin decreased from 39.46 (control) to 21.92. It was observed that the green gold nanomaterials have the ability to not only alter the fibroin protein but also enhance the cocoon and silk traits. The aim of this study was to investigate the effect of extra foliation of mulberry leaves with G-GNPs extracted from A. cepa on larval duration, mature silk gland weight, pupal weight, cocoon weight, cocoon shell weight, fibroin and sericins contents, etc. Moreover, the enhanced production of fibroin will explore a new venture in bioengineering and also in biomedical field.