Non-isothermal crystallization of NaX nanocrystals/poly (vinyl alcohol) nanocomposite

Journal of Thermal Analysis and Calorimetry - This paper reports the successful synthesis of NaX nanocrystals using an organic, additive-free hydrothermal approach. Then, solution casting was used...     

Synthesis of glycerol-thiophene nanoparticles,a suitable sensing platform for voltammetric determination of guaifenesin

Boronic acid functionalized materials have gained much attention in both chemistry and biology fields due to their multivalent covalent interactions with cis-diol containing (macro) molecules. The remarkable progress in this field has resulted in the development of their biomedical applications, such as, biosensors and nanocarriers. In this study, the spherical nanoparticles consisting of glycerol and 2,5-thiophenediylbisboronic acid were synthesized by one-pot ring opening copolymerization of a mixture of glycidol and 2,5-thiophenediylbisboronic acid. The synthesized nanoparticles were used for the modification of the glassy carbon electrode and the determination of Guaifenesin. The synthesized polymeric nanoparticles were characterized by different spectroscopic and microscopic methods including UV–vis, IR, NMR, DLS, and SEM. Additionally, the electrochemical behavior of the fabricated electrode toward Guaifenesin was investigated with cyclic voltammetry and electrochemical impedance spectroscopy.     

Simultaneous measurement of temperature and strain using a single fiber bragg grating on a tilted cantilever beam

Optical Review - Importance of simultaneous measurement of temperature and strain by fiber Bragg grating (FBG) sensors has led to innovation of several renewing techniques. Most of them are based...     

On primeness of general skew inverse Laurent series ring

Ever since the introduction, skew inverse Laurent series rings have kept growing in importance, as researchers characterized their properties (such as Noetherianness, Armendarizness, McCoyness, etc.) in terms of intrinsic properties of the base ring and studied their relations with other fields of mathematics, as for example quantum mechanics theory. The goal of our paper is to study the primeness and semiprimeness of general skew inverse Laurent series rings R((x^?1;σ,δ)), where R is an associative ring equipped with an automorphism σ and a σ-derivation δ.     

Synthesis of boronic acid‐functionalized poly(glycerol‐oligoγ‐butyrolactone): Nano‐networks for efficient electrochemical sensing of biosystems

Despite the outstanding properties of hyperbranched polyglycerols such as biocompatibility and multifunctionality, enough attention has not been paid to the synthesis of their functional copolymers. This problem has limited the structural diversity of hyperbranched polyglycerols and hampers further developments and their practical usage. In this work, butyrolactone segments were incorporated into the backbone of polyglycerols by one‐pot ring‐opening copolymerization of a mixture of glycidol and γ‐butyrolactone in the presence of tin(II) 2‐ethylhexanoate. Poly(glycerol‐oligoγ‐butyrolactone)s were then crosslinked by 2,5‐thiophenediylbisboronic acid to obtain polymeric nanonetworks with 140 nm average size. Afterwards, the gold electrode was modified by the polymeric nano‐networks, and it was used for the determination of glucose, glycated hemoglobin, and Escherichia coli in phosphate buffer solution (pH = 9.0) through cyclic voltammetry and impedance spectroscopic. Taking advantage of the straightforward synthesis, cheap precursors and multifunctionality of poly(glycerol‐oligoγ‐butyrolactone)s, they could be used for real‐time sensing of a wide range of biosystems. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1430–1439     

Numerical investigation of natural convection heat transfer of nanofluids in a Γ shaped cavity

This paper analyzes the heat transfer and fluid flow of natural convection in a Γ shaped enclosure filled with Al₂O₃/Water nanofluid that operates under differentially heated walls. The Navier–Stokes and energy equations are solved numerically. Heat transfer and fluid flow are examined for parameters of non-uniform nanoparticle size, mean nanoparticle diameter, nanoparticle volume fraction, Grashof number and different geometry of enclosure. Finite volume method is used for discretizating positional expressions, and the forth order Rung-Kuta is used for discretizating time expressions. Also an artificial compressibility technique was applied to couple continuity to momentum equations. Results indicate that using nanofluid causes an increase in the heat transfer and the Nusselt number so that for R = 0.001 in Gr = 10³, the Nusselt number 25%, in Gr = 10⁴ 26%, and in Gr = 10⁵ 28% increases. Furthermore; by decreasing the mean diameters of nanoparticles, Nusselt number increases. By increasing R parameter (d_p,min/d_p,max) and nano particle volume fraction, Nusselt number increases.     

Antibacterial and antibiofilm activity of nanochelating based silver nanoparticles against several nosocomial pathogens

The emergence of multi‐drug resistant (MDR) bacteria and dynamic pattern of infectious diseases demand to develop alternative and more effective therapeutic strategies. Silver nanoparticles (AgNPs) are among the most widely commercialized engineered nanomaterials, because of their unique properties and increasing use for various applications in nanomedicine. This study for the first time aimed to evaluate the antibacterial and antibiofilm activities of newly synthesized nanochelating based AgNPs against several Gram‐positive and ‐negative nosocomial pathogens. Nanochelating technology was used to design and synthesize the AgNPs. The cytotoxicity was tested in human cell line using the MTT assay. AgNPs minimal inhibitory concentration (MIC) was determined by standard broth microdilution. Antibiofilm activity was assayed by a microtiter‐plate screening method. The two synthesized AgNPs including AgNPs (A) with the size of about 20‐25 nm, and AgNPs (B) with 30‐35 nm were tested against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, and Pseudomonas aeruginosa. AgNPs exhibited higher antibacterial activity against Gram‐positive strains. AgNPs were found to significantly inhibit the biofilm formation of tested strains in concentration 0.01 to 10 mg/mL. AgNPs (A) showed significant effective antibiofilm activity compared to AgNPs (B). In summary, our results showed the promising antibacterial and antibiofilm activity of our new nanochelating based synthesized AgNPs against several nosocomial pathogens.