Simulation of heat and mass transfer on peristaltic flow of hyperbolic tangent fluid in an asymmetric channel

In the present analysis, the influence of heat and mass transfer on the peristaltic flow of a hyperbolic tangent fluid in an asymmetric channel has been discussed. The highly nonlinear equations are simplified under lubrication approach. The perturbation and numerical solutions of the problem are not only discussed but the validity of the results is also being checked. The graphical results of the problem under discussion are also being brought under consideration to see the behavior of various physical parameters. Copyright © 2012 John Wiley & Sons, Ltd.     

Yolk–shell microspheres assembled from Preyssler‐type NaP5W30O11014− polyoxometalate and MIL‐101(Cr) metal–organic framework: A new inorganic–organic nanohybrid for fast and selective removal of cationic organic dyes from aqueous media

Novel inorganic–organic yolk–shell microspheres based on Preyssler‐type NaP₅W₃₀O₁₁₀^14? polyoxometalate and MIL‐101(Cr) metal–organic framework (P₅W₃₀/MIL‐101(Cr)) were synthesized by reaction of K_12.5Na_1.5[NaP₅W₃₀O₁₁₀], Cr(NO₃)₃·9H₂O and terephthalic acid under hydrothermal conditions at 200°C for 24 h. The as‐prepared yolk–shell microspheres were fully characterized using various techniques. All analyses confirmed the incorporation of the Preyssler‐type NaP₅W₃₀O₁₁₀^14? polyoxometalate into the three‐dimensional porous MIL‐101(Cr) metal–organic framework. The results revealed that P₅W₃₀/MIL‐101(Cr) demonstrated rapid adsorption of cationic methylene blue (MB) and rhodamine B (RhB) with ultrahigh efficiency and capacity, as well as achieving rapid and highly selective adsorption of MB from MB/MO (MO = methyl orange), MB/RhB and MB/RhB/MO mixtures. The P₅W₃₀/MIL‐101(Cr) adsorbent not only exhibited a high adsorption capacity of 212 mg g^?1, but also could quickly remove 100% of MB from a dye solution of 50 mg l^?1 within 8 min. The effects of some key parameters such as adsorbent dosage, initial dye concentration and initial pH on dye adsorption were investigated in detail. The equilibrium adsorption data were better fitted by the Langmuir isotherm. The adsorption kinetics was well modelled using a pseudo‐second‐order model. Also, the inorganic–organic hybrid yolk–shell microspheres could be easily separated from the reaction system and reused up to four times without any change in structure or adsorption ability. The stability and robustness of the adsorbent were confirmed using various techniques.     

Preparation,formulation, and chemical characterization of silver nanoparticles using Melissa officinalis leaf aqueous extract for the treatment of acute myeloid leukemia in vitro and in vivo conditions

The demand for nanoparticles is increasing day by day due to their wide range of applications in various areas including pharmaceutical industry. Nanoparticles are formally synthesized by chemical methods in which the toxic and flammable chemicals are used. Synthesis of nanoparticles from various biological systems has been reported, but among all, biosynthesis of nanoparticles from plants is considered as the most suitable method. The current study confirms the potential of aqueous extract of Melissa officinalis grown under in vitro condition for the green synthesis of silver nanoparticles (AgNPs). Also, we revealed the cytotoxicity, antioxidant, and anti-acute myeloid leukemia effects of AgNPs compared to mitoxantrone in a leukemic mouse model. The synthesized AgNPs were characterized using several techniques including UV–Vis., FT-IR, TEM, FE-SEM, and EDS. In vivo experiment, induction of acute myeloid leukemia was done by DMBA in 75 mice. The obtained results were fed into SPSS-22 software and analyzed by one-way ANOVA. By quantitative real-time PCR, S1PR1 and S1PR5 mRNA expression in lymphocytes were significantly (p ≤ 0.01) increased by treating the leukemic mice with the AgNPs and mitoxantrone. Also, AgNPs similar to mitoxantrone, significantly (p ≤ 0.01) enhanced the platelet, lymphocyte, and RBC parameters and the anti-inflammatory cytokines (IL4, IL5, IL10, IL13, and IFNα) and reduced the total WBC, blast, monocyte, neutrophil, eosinophil, and basophil counts and the pro-inflammatory cytokines (IL1, IL6, IL12, IL18, IFNY, and TNFα) as compared to the untreated mice. In vitro experiment, AgNPs similar to mitoxantrone had low cell viability dose-dependently against murine C1498, human HL-60/vcr, and 32D-FLT3-ITD cell lines without any cytotoxicity on HUVEC cell line. Furthermore, the DPPH assay showed similar antioxidant potentials for AgNPs and mitoxantrone. Above results approve the excellent anti-acute myeloid leukemia, cytotoxicity, and antioxidant properties of AgNPs compared to mitoxantrone.     

Nanostructured conducting molecularly imprinted polymer for selective extraction of salicylate from urine and serum samples by electrochemically controlled solid-phase micro-extraction

Overoxidized polypyrrole (OPPy) films templated with salicylate (SA) have been utilized as conducting molecular imprinted polymers (CMIPs) for potential-induced selective solid-phase micro-extraction processes. Various important fabrication factors for controlling the performance of the OPPy films have been investigated using fluorescence spectrometry. Several key parameters such as applied potential for uptake, release, pH of uptake and release solution were varied to achieve the optimum micro-extraction procedure. The film template with SA exhibited excellent selectivity over some interference. The calibration graphs were linear in the ranges of 5×10(-8) to 5×10(-4) and 1.2×10(-6) to 5×10(-4)mol mL(-1) and the detection limit was 4×10(-8) mol L(-1). The OPPy film as the solid-phase micro-extraction absorbent has been applied for the selective clean-up and quantification of trace amounts of SA from physiological samples. The results of scanning electron microscopy (SEM) have confirmed the nano-structure morphologies of the films.     

Catalyst-Free Efficient Regioselective Ring Opening of Oxiranes with Thioacids in Water

Epoxide ring opening with thioacetic acid and thiobenzoic acid was investigated in the presence of water under catalyst-free conditions. This green and simple process gave an excellent yield. With simple decanting, the products were obtained in high purity and on a large scale. In this process, alkyl halide and ester cleavage were not observed.

Application of Solid-Phase Extraction Coupled with Dispersive Liquid–Liquid Microextraction for the Determination of Benzaldehyde in Injectable Formulation Solutions

Solid-phase extraction followed by dispersive liquid–liquid microextraction (SPE-DLLME) technique has been developed as a new analytical approach for extracting, cleaning up and preconcentrating benzaldehyde, a toxic oxidation product of the widely used preservative and co-solvent benzyl alcohol, in injectable formulation solutions. SPE of benzaldehyde from samples was carried out using C₁₈ sorbent. After the elution of benzaldehyde from the sorbent by using acetonitrile, DLLME technique was performed on the obtained solution. Benzaldehyde was preconcentrated by using DLLME technique. Thus, 1.5 mL acetonitrile extract (disperser solvent) and 55.0 µL 1,2-dichloroethane (extraction solvent) were added to 5 mL ultra pure water and a DLLME technique was applied. Several variables that govern the proposed technique were studied and optimized. Under optimum conditions, the method detection limit (LOD) of benzaldehyde calculated as three times the signal-to-noise ratio (S/N) was 0.08 µg L^?1. The relative standard deviation (RSD) for four replicates was 5.8 %. The calibration graph was linear within the concentration range of 0.5–500 µg L^?1 for benzaldehyde. The proposed method has been successfully applied to the analysis of the benzaldehyde in injectable formulation solutions (diclofenac, vitamin B-complex and voltaren) and the relative recoveries were between 88 and 92 % and show that matrix has a negligible effect on the performance of the proposed method.     

Biocompatible fluorescent polyamine‐based cyclophosphazene hybrid nanospheres for targeted cell imaging

Fluorescent nanoprobes are highly desirable toolkit for bioimaging applications. This study reports the first example for the synthesis of a nontoxic prototypical fluorescent organic compound 2‐benzo[d]thiazol‐2‐yl)‐3‐(2‐chloro‐4‐(dimethylamino)phenyl)acrylonitrile (BCA) and its entrapment into the poly[cyclotriphosphazene‐co‐polyethyleneimine] cross‐linked (PCPEI) nanospheres named as BCA@PCPEI for targeted cell imaging application. The as‐prepared BCA@PCPEI nanospheres were thoroughly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier transform infrared (FTIR), thermogravimetric analysis (TGA), and phosphorus‐31 nuclear magnetic resonance (³¹P‐NMR) analyses. The surface functional analysis of the nanospheres was performed by X‐ray photoelectron spectroscopy (XPS), which proves that the content ratios of elements belong to the precursors concentrations. The as‐prepared nanospheres displayed emission at 606 nm with bright orange fluorescence at any concentration. Moreover, the nanospheres were also less cytotoxic and maintained remarkable cell viability up to 100 μg/mL. Owing to the fluorescence with higher emission, this material has shown excellent cell imaging performance with better targeting ability to HeLa cells.