L-proline catalyzed multicomponent domino reaction in polyethyleneglycol-400 for regioselective synthesis of pyrazolyl-tetrahydroindazolones under microwave irradiation

A simple and convenient approach for the synthesis of pyrazolyl-tetrahydroindazolones via L-proline catalyzed three component domino reaction of arylhydrazine, dimedone and pyrazole aldehyde in polyethyleneglycol-400 (PEG-400) under microwave irradiation is described. This novel and green protocol proceeds smoothly in good to excellent yields and provides several advantages such as shorter reaction time, metal-free reaction conditions, simple work-up procedures. Also, recycling of the catalyst and solvent was observed without the loss of activity for three (03) runs.     

Chromogenic and fluorogenic detection of copper ions in the solution and intracellular media

The development of a fluorescent sensor for the trace detection of the metallic contamination in the ecosystem and biological media have been a demand to reduce the health risk and environmental protection. Herein, we report the synthesis of 2‐formyl‐5‐picolinyl‐substituted rhodamine B derivative through Schiff base formation for the trace detection of the copper ions in the aqueous organic media as well as inside the live cells via bioimaging experiments. The ligand was successfully employed to detect the minute copper level ratiometrically through the chromogenic and fluorogenic response. The detection limit of the sensor was found to be 0.54 × 10^?9 mol/L using 3 σ/slope relations. The reversible behavior of the ligand copper complex was determined using sulfide ions that regenerate the entire native properties of the ligands by snatching copper from the complex. The bioimaging experimental results represent the efficient membrane permeability of ligands with the minimum level of toxicity in the measured range found by the MTT assay. The appearance of bright red fluorescence from the BHK‐21 (hamster kidney fibroblast) cells upon treatment of the ligand incubated cells with the copper ions represents the utility of the proposed sensor for the copper detection probe in the intracellular media.     

Spreader-CDR system for efficient,reproducible, and frugal western blot

Efficient antibody incubation is a vital step for successful western blot. During the incubation, a thin antibody-depleted layer is created around the blotting membrane, which limits antibody binding. Although the conventional batch shaking method is ineffective against it, this layer can be easily disrupted by cyclic draining and replenishing (CDR) of the antibody solution during membrane incubation. Previously, we introduced a closed and rotating cylindrical chamber as a tool to implement CDR for western blots (rCDR). A new open bucket-style chamber was devised for easier operation and the possibility of process automation. Instead of rotation as in rCDR, rocking it back and forth achieved the CDR antibody incubation (R-CDR). The chamber was then equipped with a spreader-rod to facilitate the uniform movement of the antibody solution across the membrane surface. Hence, it was named spreader CDR (S-CDR). Compared to the batch incubation method, both the S-CDR and R-CDR devices produced significantly enhanced signals and developed faster results. There were several additional benefits of using the spreader-rod, which included uniform antibody binding across the membrane, reduced usage of antibodies, and the ability to recover results even from mishandled, creased membranes. The S-CDR device ensures better blots and can be easily implemented in existing western blot protocols.     

Group theoretical analysis for magnetohydrodynamic generalized Stokes’ flow and radiative heat transfer model of a non-Newtonian nanofluid with heat generation/absorption

Journal of Thermal Analysis and Calorimetry - The fully developed boundary layer flow and heat transfer model of an unsteady, incompressible, electrically conducting, optically thick and...     

Fabrication and Properties of Polycaprolactone Composites Containing Calcium Phosphate-Based Ceramics and Bioactive Glasses in Bone Tissue Engineering: A Review

Polycaprolactone (PCL) is a bioresorbable and biocompatible polymer that has been widely used in long-term implants and controlled drug release applications. However, when it comes to tissue engineering, PCL suffers from some shortcomings such as slow degradation rate, poor mechanical properties, and low cell adhesion. The incorporation of calcium phosphate-based ceramics and bioactive glasses into PCL has yielded a class of hybrid biomaterials with remarkably improved mechanical properties, controllable degradation rates, and enhanced bioactivity that are suitable for bone tissue engineering. This review presents a comprehensive study on recent advances in the fabrication and properties of PCL-based composite scaffolds containing calcium phosphate-based ceramics and bioglasses in terms of porosity, degradation rate, mechanical properties, in vitro and in vivo biocompatibility and bioactivity for bone regeneration applications. The fabrication routes range from traditional methods such as solvent casting and particulate leaching to novel approaches including solid free-form techniques.     

Selective electroless metal deposition using microcontact printing of phosphine-phosphonic acid inks

We report a low-cost approach to selectively deposit films of nickel and copper on glass substrates. Our approach uses microcontact printing of organic inks containing phosphonic acid groups to bind the ink to a glass substrate and phosphine groups to bind a colloidal catalyst that initiates electroless metallization. We demonstrate this procedure by fabricating patterned nickel and copper films with areas as large as 15 cm2 and minimum feature sizes of approximately 2 microm. We present studies on the use of two ink types, an oligomer and a bifunctional molecule, and demonstrate that pattern quality and adhesion of the metallized films depends on the molecular weight of the ink and the ratio of phosphine and phosphonic acid groups.     

Ion chemistry of α-diazoketones. 1. A collissional activation study of 1-diazo-3-phenoxypropan-2-one upon elecgtron impact

The gaseous ionic products of 1-diazo-3-phenoxypropan-2-one upon electron impact show that cyclization reactions, which have counterparts in condensed-phase chemistry, occur in competition with a mass spectral Wolff type rearrangement.