A simple route for the synthesis of novel N-alkyl-2-(alkylthio)-1H-imidazole derivatives

Novel $N$ -alkyl-2-(alkylthio)-1 $H$ -imidazole derivatives were synthesized in a single step by an efficient and simple method in high yields. Readily available starting materials, mild reaction conditions, operational simplicity and novelty are the key advantages of this method. Besides their novel structures, these compounds may have important biological activities and industrial applications.     

Tannic acid-coated zeolite Y nanoparticles as novel drug nanocarrier with controlled release behavior and anti-protozoan activity against Trichomonas gallinae

In this study, a pH-sensitive drug release system was prepared by zeolite Y nanoparticles and tannic acid. Zeolite Y nanoparticles were synthesized via hydrothermal synthesis of colloidal suspensions and after that, were coated with tannic acid. In order to evaluate its performance, metronidazole as an anti-protozoan drug was loaded into nanocarriers via immersing method to study the in-vitro drug delivery behavior. This nanocomposite carriers represented pH-sensitive behavior and had more and faster release in acidic medium. In-vitro effects of metronidazole-loaded nanoparticles was measured against Trichomonas gallinae trophozoites in Trypticase Yeast extract Maltose medium. The results suggested that metronidazole-loaded and tannic acid-modified zeolite Y nanoparticles could be a potential anti-trichomonal agent.     

Fabrication of graphene‐silver/polyurethane nanofibrous scaffolds for cardiac tissue engineering

The graphene‐based nanocomposites are considered as great candidates for enhancing electrical and mechanical properties of nonconductive scaffolds in cardiac tissue engineering. In this study, reduced graphene oxide‐silver (rGO‐Ag) nanocomposites (1 and 2 wt%) were synthesized and incorporated into polyurethane (PU) nanofibers via electrospinning technique. Next, the human cardiac progenitor cells (hCPCs) were seed on these scaffolds for in vitro studies. The rGO‐Ag nanocomposites were studied by X‐ray diffraction (XRD), Raman spectroscopy, and transmission electron microscope (TEM). After incorporation of rGO‐Ag into PU nanofibers, the related characterizations were carried out including scanning electron microscope (SEM), TEM, water contact angle, and mechanical properties. Furthermore, PU and PU/nanocomposites scaffolds were used for in vitro studies, wherein hCPCs showed good cytocompatibility via 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl tetrazolium bromide (MTT) assay and considerable attachment on the scaffold using SEM studies. Real‐time polymerase chain reaction (PCR) and immunostaining studies confirmed the upregulation of cardiac specific genes including GATA‐4, T‐box 18 (TBX 18), cardiac troponin T (cTnT), and alpha‐myosin heavy chain (α‐MHC) in the PU/rGO‐Ag scaffolds in comparison with neat PU ones. Therefore, these nanofibrous rGO‐Ag–reinforced PU scaffolds can be considered as suitable candidates in cardiac tissue engineering.     

Experimental investigation of paraffin nano-encapsulated phase change material on heat transfer enhancement of pulsating heat pipe

Journal of Thermal Analysis and Calorimetry - In this study, a mixture of nano-encapsulated phase change materials in water has been used as the working fluid in a pulsating heat pipe in order to...     

An electrochemical sensor based on Pt nanoparticles decorated over-oxidized polypyrrole/reduced graphene oxide nanocomposite for simultaneous determination of two neurotransmitters dopamine and 5-Hydroxy tryptamine in the presence of ascorbic acid

Abstract

In this study, the Pt nanoparticles/over-oxidized polypyrrole nanofiber/reduced graphene oxide (Pt NPs/OPPy/RGO) nanocomposite was electrochemically synthesized and used to modify a glassy carbon electrode. To confirm the Surface morphology and characterization of the nanocomposite, field emission scanning microscopy (FE-SEM), X-ray diffraction (XRD), Raman, FT-IR, and X-ray photoelectron spectroscopy (XPS) were used. Simultaneous determination of these species showed one linear response 0.1–250.0?μM and two linear responses 0.5–10.0?μM and 10.0–470.0?μM, with detection limits 42?nM and 106?nM (S/N?=?3) for DA and 5-HT, respectively. Finally, the analytical application of this modified electrode was investigated in the human blood plasma.     

Electrochemical behavior of Al2O3/Al composite coated Al electrodes through surface mechanical alloying in alkaline media

The behavior of $A{l}_2{O}_3/Al$ composite coated Al electrodes fabricated by surface mechanical alloying ‘SMA’ was studied. The work was accomplished using Cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques in alkaline media $2MKOH$ were done at room temperature. Results show hydroxyl ions accumulate on the surface due to Al deformation micro cavities filling with $A{l}_2{O}_3$ until full charge blockage reached. A barrier cover layer development causing an increase of both resistance and capacitance as it becomes more stable and thinner with exposure time increase. Migrating hydroxyl ion inside micro cavity changed its composition from Al₂O₃ to stable tetrahedral $Al{\left(OH\right)}_4^{?}$ aluminate ions. Therefore future benefits could be reached by developing such surfaces having charge accumulation that enables environmental interaction.     

Induced secondary metabolites from the endophytic fungus Aspergillus versicolor through bacterial co-culture and OSMAC approaches

Two new cryptic 3,4-dihydronaphthalen-(2H)-1-one (1-tetralone) derivatives, aspvanicin A (1) and its epimer aspvanicin B (2), as well as several known cryptic metabolites (3–8), were obtained from the ethyl acetate extract of the co-culture of the endophytic fungus Aspergillus versicolor KU258497 with the bacterium Bacillus subtilis 168 trpC2 on solid rice medium. When A. versicolor was cultured axenically in liquid Wickerham medium supplemented with 3.5% DMSO, an additional three known secondary metabolites (9–11) were isolated that were lacking when the fungus was fermented on rice medium. The structures of the new compounds were elucidated using one- and two-dimensional NMR spectroscopy as well as HRESIMS. The relative and absolute configurations of 1 and 2 were determined by the combination of NMR and electronic circular dichroism (ECD) analysis aided by DFT conformational analysis and TDDFT-ECD calculations. The ECD calculations revealed that although the sign of the blue-shifted overlapping n-π¹ ECD transition follows the helicity rule of cyclic aryl ketones, the calculation of low-energy conformers and ECD spectra was necessary to determine the stereochemistry. All metabolites were assessed for their antibacterial and cytotoxic activities; one of the new diastereomers, compound 2, showed moderate cytotoxic activity against the mouse lymphoma cell line L5178Y.     

Sonication-assisted preparation of a nanocomposite consisting of reduced graphene oxide and CdSe quantum dots,and its application to simultaneous voltammetric determination of ascorbic acid,dopamine and uric acid

Microchimica Acta - Accurate detection of temperature and oxygen concentration at the cellular level is important in tumor diagnosis. Multifunctional nanocomposites are described that consist of...     

Synthesis and structural characterization for novel mixed-donor ligand palladium (II) based on graphene and oxime: its application as a highly stable and efficient recyclable catalyst

In this article, the palladium (II) mixed-ligand complex synthesized with reduced graphene oxides containing tetraethoxysilane and menthone oxime was used as an efficient solid catalyst for the Heck coupling reaction. To maintain stability and catalytic activity in the C–C bond reaction, graphene was considered due to the available surface as the solid support. Then, the structure of new heterogeneous catalyst was investigated by FT-IR, UV–Vis DRS, FE-SEM, EDX, AFM, XRD, ICP-OES, Raman, and TGA. The newly synthesized nanocatalyst have beneficial properties, including product’s easy separation, the shorter time to react, purity products (yield 79–99%), and easier work-up procedure. Furthermore, the catalyst was reused six times without significant degradation in catalytic activity and performance.     

Experimental determination of acetamiprid pesticide residue in three different types of pistachio by ion mobility spectrometry and using QuEChERS method in the different temperatures and in the presence of ammonia as dopant gas

In this project, Ion Mobility Spectrometer (IMS) instrument in the positive mode and with corona ionization source was utilized to determine the residue of acetamiprid pesticide in three different types of pistachio (Akbari, Fandoghi and Kalachuchi). The QuEChERS method, notable because of easy and quick preparation of sample and using lower amounts of organic solvents with harmful environmental effects and high costs, was used in this study. Many experiments were performed in the different temperatures in order to obtain optimum temperature for cell and injection. Ammonia and acetone were considered as dopant substances and it turned out that the ammonia gas, contrary to acetone, increased significantly the signal intensity and sensitivity and avoided the overlap of desired peaks. The LOD of device for acetamiprid pesticide was estimated to be 0.5 μg g^?1 and the LOQ of instrument was obtained as 1.66 μg g^?1. The calibration curve was in the dynamic range between 0.5–11.5 μg g^?1 and the Correlation Coefficient was 0.998. Also, the ion mobility and the reduced ion mobility were calculated for acetamiprid ion. After analysis of five samples with IMS instrument, the acetamiprid residue was determined and it turned out that it was under allowed limit in all three types of pistachio. In addition, the amount of acetamiprid residue was higher for Akbari type relative to Fandoghi and Kalachuchi ones. The reason for this observation is the higher vulnerability of Akbari trees to insects and pests and this in turn causes more pesticide to be consumed.