MHD power-law fluid flow and heat transfer over a non-isothermal stretching sheet

This article presents a numerical solution for the magnetohydrodynamic (MHD) non-Newtonian power-law fluid flow over a semi-infinite non-isothermal stretching sheet with internal heat generation/absorption. The flow is caused by linear stretching of a sheet from an impermeable wall. Thermal conductivity is assumed to vary linearly with temperature. The governing partial differential equations of momentum and energy are converted into ordinary differential equations by using a classical similarity transformation along with appropriate boundary conditions. The intricate coupled non-linear boundary value problem has been solved by Keller box method. It is important to note that the momentum and thermal boundary layer thickness decrease with increase in the power-law index in presence/absence of variable thermal conductivity.     

Molecular transition-metal phosphonates

Molecular transition-metal phosphonates are of relatively recent origin and can be assembled by several synthetic strategies. The nuclearity and the structure of the metal aggregates can be modulated by several factors including the stoichiometry of the reactants, nature of the metal precursor and the type of phosphonic acid used. This perspective summarizes some of the recent work carried out on copper(II)-, zinc(II)- and cadmium(II) phosphonates with particular emphasis on their synthesis and structure.     

Targeted highly sensitive detection of multi-drug resistant Salmonella DT104 using gold nanoparticles

Monoclonal antibody-conjugated popcorn-shape gold nanotechnology-driven approach to selectively detect multiple drug resistant (MDRB) Salmonella typhimurium DT104 bacteria has been developed. We demonstrate that the gold nanotechnology based assay is capable of measuring the amount of MDRB in food samples.     

Rapid Colorimetric Identification and Targeted Photothermal Lysis of Salmonella Bacteria by Using Bioconjugated Oval‐Shaped Gold Nanoparticles

Salmonella bacteria are the major cause for the infection of 16 million people worldwide with typhoid fever each year. Antibiotic‐resistant Salmonella strains have been isolated from various food products. As a result, the development of ultrasensitive sensing technology for detection and new approaches for the treatment of infectious bacterial pathogens that do not rely on traditional therapeutic regimes is very urgent for public health, food safety, and the world economy. Driven by this need, we report herein a nanotechnology‐driven approach that uses antibody‐conjugated oval‐shaped gold nanoparticles to selectively target and destroy pathogenic bacteria. Our experiments have shown the use of a simple colorimetric assay, with an anti‐salmonella antibody conjugated to oval‐shaped gold nanoparticles, for the label‐free detection of S. typhimurium with an excellent detection limit (10⁴ bacteria per mL) and high selectivity over other pathogens. When bacteria conjugated to oval‐shaped gold nanoparticles were exposed to near‐infrared radiation, a highly significant reduction in bacterial cell viability was observed due to photothermal lysis. Ideally, this nanotechnology‐based assay would have enormous potential for rapid, on‐site pathogen detection to avoid the distribution of contaminated foods.     

A room temperature alternative of the Claisen rearrangement route to ortho allylated phenols: unique reactivity pattern of allylindium reagents

Quinol ethers and quinone monoketals are shown to undergo formal anti-Michael addition reactions with allylindium reagents at room temperature to give only ortho allylated phenols in good yields.     

Liquid biopsy technologies based on membrane microfluidics: High-yield purification and selective quantification of biomarkers in nanocarriers

Liquid biopsy, screening cancer non-invasively and frequently by detecting and quantifying molecular markers in physiological fluids, would significantly improve cancer survival rate but it remains a distant goal. The key obstacles presented by the highly heterogeneous samples are rapid/high-yield purification and precise/selective marker capture by their antibody and oligo probes. As irregular expressions of these molecular biomarkers are the key signals, quantifying only those from the cancer cells would greatly enhance the performance of the screening tests. The recent discovery that the biomarkers are carried by nanocarriers, such as exosomes, with cell-specific membrane proteins suggests that such selection may be possible, although a new suite of fractionation and quantification technologies would need to be developed. Although under-appreciated, membrane microfluidics has made considerable contributions to resolving these issues. We review the progress made so far, based on ion-selective, track-etched, and gel membranes and advanced electrophoretic and nano-filtration designs, in this perspective and suggest future directions.