Objective(s): Biocompatibility, non-toxicity, minimal allergenicity, and biodegradability are all characteristics of chitosan. Other biological properties of chitosan have been reported, including antitumor, antimicrobial and antioxidant activities. This research aim is the synthesis of drug compounds by preparation and characterization of polymer chitosan Schiff base and chitosan Schiff base / Poly vinyl alcohol / poly vinyl pyrrolidone Nanocomposite and study applications (anticancer cell line, antimicrobial agents). Methods: Chitosan Schiff base was prepared from the reaction of chitosan with carbonyl group of 4-nitro benzaldehyde. Polymer blend have been prepared by solution casting method. Chitosan Schiff base mixing with PVA and PVP. Green synthesis of AuNPs and AgNPs by onion peals extract as reducing agent. Nanocomposites were prepared by mixing 10 mL of chitosan Schiff base, 5 mL PVA and 5 mL of PVP with 25 mL of two different concentrations (100, 200 ppm) of AuNPs and AgNPs. In vitro bacterial activities polymer blends and Au, Ag nano composites were performed against pathogenic bacteria such as the Acinetobacter baumannii, Staphylococcus aureus, Pseudomonas aeruginosa and Esherichia coli. Cancer cell line (AMJ-13) cell line. Results: The prepared AgNPs and AuNPs were characterized by UV-visible spectroscopy, SEM microscopy and XRD analysis. UV-vis spectrum of AuNPs at 543 nm and AgNPs at 425 nm, particles size of AuNPs 24.74 nm and AgNPs 18.77 nm. The polymer blends and nano composites were characterized by FT-IR, SEM, DSC and TGA. DSC analysis investigated the polymer blend and nano composites shows a good thermal stability for all prepared compounds. The inhibition zone of blend and nanocomposites The Inhibition zone of blend and Nano composites ranging between (8-15) millimetre with concentration of 20 mg. The inhibition rate of blend and Nanocomposites ranging between (1.33 – 77.33) for all compounds. IC 50 of blend and Nanocomposites ranging between (26.04 - 183.56) µg for all compounds. Conclusions: The prepared AgNPs and AuNPs were characterized by UV-visible spectroscopy, SEM microscopy and XRD analysis. UV-vis spectrum of AuNPs at 543 nm and AgNPs at 425 nm, particles size of AuNPs 24.74 nm and AgNPs 18.77 nm. The polymer blends and nano composites were characterized by FT-IR, SEM, DSC and TGA. DSC analysis investigated the polymer blend and nano composites shows a good thermal stability for all prepared compounds. The inhibition zone of blend and nanocomposites The Inhibition zone of blend and Nano composites ranging between (8-15) millimetre with concentration of 20 mg. The inhibition rate of blend and Nanocomposites ranging between (1.33 – 77.33) for all compounds. IC 50 of blend and Nanocomposites ranging between (26.04 - 183.56) µg for all compounds.
Background: Marginal adaptation is critical for long – term success of crown and bridge restoration. Computer aided design / computer aided manufacture (CAD/ CAM) system is gaining more importance in the fabrication of dental restoration. Objective: The aim of this study is to evaluate the effect of crystallization firing on the vertical marginal gap of IPS. emax CAD crowns which fabricated with two different CAD/CAM systems .Materials and Methods: Twenty IPS e.max CAD crowns were fabricated. We had two major groups (A, B) (10 crowns for each group) according to the CAD/CAM system being used: Group A: fabricated with Imes - Icore CAD/CAM system; Group B: fabricated with In Lab Sirona CAD/CAM system. Each group was subdivided into two s
... Show MoreThe melting duration in the photovoltaic/phase-change material (PV/PCM) system is a crucial parameter for thermal energy management such that its improvement can realize better energy management in respect to thermal storage capabilities, thermal conditions, and the lifespan of PV modules. An innovative and efficient technique for improving the melting duration is the inclusion of an exterior metal foam layer in the PV/PCM system. For detailed investigations of utilizing different metal foam configurations in terms of their convective heat transfer coefficients, the present paper proposes a newly developed mathematical model for the PV/PCM–metal foam assembly that can readily be implemented with a wide range of operating condition
... Show MoreWe aimed to obtain magnesium/iron (Mg/Fe)-layered double hydroxides (LDHs) nanoparticles-immobilized on waste foundry sand-a byproduct of the metal casting industry. XRD and FT-IR tests were applied to characterize the prepared sorbent. The results revealed that a new peak reflected LDHs nanoparticles. In addition, SEM-EDS mapping confirmed that the coating process was appropriate. Sorption tests for the interaction of this sorbent with an aqueous solution contaminated with Congo red dye revealed the efficacy of this material where the maximum adsorption capacity reached approximately 9127.08 mg/g. The pseudo-first-order and pseudo-second-order kinetic models helped to describe the sorption measure
Acinetobacter baumannii (A. baumannii ) is considered a critical healthcare problem for patients in intensive care units due to its high ability to be multidrug-resistant to most commercially available antibiotics. The aim of this study is to develop a colorimetric assay to quantitatively detect the target DNA of A. baumannii based on unmodified gold nanoparticles (AuNPs) from different clinical samples (burns, surgical wounds, sputum, blood and urine). A total of thirty-six A. baumannii clinical isolates were collected from five Iraqi hospitals in Erbil and Mosul provinces within the period from September 2020 to January 2021. Bacterial isolation and biochemical identification of isolates
... Show MoreThe beginning of COVID-19 in Wuhan, China in late December 2019 and its worldwide transmission has led the World Health Organization to formally address the pandemic. The pandemic has imposed influential impacts on different environmental, economic, social, health, and living aspects. Publishing in scholastic journals was not immune from these impacts.
In the present study, the effect of new cross-section fin geometries on overall thermal/fluid performance had been investigated. The cross-section included the base original geometry of (triangular, square, circular, and elliptical pin fins) by adding exterior extra fins along the sides of the origin fins. The present extra fins include rectangular extra fin of 2 mm (height) and 4 mm (width) and triangular extra fin of 2 mm (base) 4 mm (height). The use of entropy generation minimization method (EGM) allows the combined effect of thermal resistance and pressure drop to be assessed through the simultaneous interaction with the heat sink. A general dimensionless expression for the entropy generation rate is obtained by con
... Show MoreThis study offers numerical simulation results using the ABAQUS/CAE version 2019 finite element computer application to examine the performance, and residual strength of eight recycle aggregate RC one-way slabs. Six strengthened by NSM CFRP plates were presented to study the impact of several parameters on their structural behavior. The experimental results of four selected slabs under monotonic load, plus one slab under repeated load, were validated numerically. Then the numerical analysis was extended to different parameters investigation, such as the impact of added CFRP length on ultimate load capacity and load-deflection response and the impact of concrete compressive strength value on the structural performance of
... Show MorePure nano Ferro fluid was synthesized by chemical co-precipitation method. The composite of polyaniline with nano sized Ferro fluid was prepared by In-situ–chemical oxidation polymerization method with ammonium per sulphate as an oxidant in aqueous hydrochloric acid under constant stirring at room temperature. The optical properties, absorption, transmission, optical energy gap (Eg) and optical constant refractive index (n) have been investigated. The value of the Eg decreased with increasing Ferro fluid concentration.