Esophageal atresia and tracheoesophageal fistula: success and failure rates in the United Arab Emirates

Randomized, prospective trials examining the effectiveness of carotid endarterectomy have given distinct information into the mechanisms and prevention of embolic strokes. The North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Atherosclerosis Study (ACAS) have demonstrated the benefits of carotid endarterectomy for patients who meet the precise selection criteria and are treated according to established study protocols. The existing challenge to clinicians lies in the application of trial results to the individual patient.     

Influence of absorber doping in a-SiC：H/a-Si：H/a-SiGe：H solar cells

This work deals with the design evaluation and influence of absorber doping for a-Si:H/a-SiC:H/a-SiGe:H based thin-film solar cells using a two-dimensional computer aided design (TCAD) tool. Various physical parameters of the layered structure, such as doping and thickness of the absorber layer, have been studied. For reliable device simulation with realistic predictability, the device performance is evaluated by implementing necessary models (e.g., surface recombinations, thermionic field emission tunneling model for carrier transport at the heterojunction, Schokley-Read Hall recombination model, Auger recombination model, bandgap narrowing effects, doping and temperature dependent mobility model and using Fermi-Dirac statistics). A single absorber with a graded design gives an efficiency of 10.1% for 800 nm thick multiband absorption. Similarly, a tandem design shows an efficiency of 10.4% with a total absorber of thickness of 800 nm at a bandgap of 1.75 eV and 1.0 eV for the top a-Si and bottom a-SiGe component cells. A moderate n-doping in the absorber helps to improve the efficiency while p doping in the absorber degrades efficiency due to a decrease in the V_OC (and fill factor) of the device.     

SPION@APTES@FA-PEG@Usnic Acid Bionanodrug for Cancer Therapy

In this work, we aimed to develop stable usnic acid (UA)-conjugated superparamagnetic iron oxide nanoparticles (SPIONs) as a potential drug carrier for in vitro analysis of MCF-7 (breast cancer cell line), HeLa (cervix cancer cell line), L929 (mouse fibroblast cell line), U87 (glioblastoma cell line, brain cancer), and A549 (human lung cancer cell line) cell lines. SPIONs were synthesized via the polyol method and functionalized with APTES using the Stöber method. Carboxylated polyethylene glycol (PEG-COOH), folic acid (FA), and carboxylated luteolin (CL) were conjugated on the surface via a carboxylic/amine group using the nanoprecipitation method, respectively. X-ray powder diffraction analysis confirmed the purity of the product with crystallite size of around 11 nm. Fourier-transformed infrared spectrophotometer (FT-IR) analyses explained the conjugation of all functional groups to the surface of SPIONs. The percentages of inorganic and organic content in the products were investigated via thermal gravimetric analyzer (TGA). For morphological analysis, a transmission electron microscope (TEM) was used. The superparamagnetic property of the product was also confirmed by vibrating sample magnetometer (VSM).     

Influence of Chemical Reaction on Mass Transport in Yield Stress Exhibiting Flow Regime

Theoretical Foundations of Chemical Engineering - In this study, the simulations for first-order chemical reactions (constructive and destructive) in the flow of the Casson fluid with...     

Biomolecular conjugation inside synthetic polymer nanopores via glycoprotein-lectin interactions

We demonstrate the supramolecular bioconjugation of concanavalin A (Con A) protein with glycoenzyme horseradish peroxidase (HRP) inside single nanopores, fabricated in heavy ion tracked polymer membranes. Firstly, the HRP-enzyme was covalently immobilized on the inner wall of the pores using carbodiimide coupling chemistry. The immobilized HRP-enzyme molecules bear sugar (mannose) groups available for the binding of Con A protein. Secondly, the bioconjugation of Con A on the pore wall was achieved through its biospecific interactions with the mannose residues of the HRP enzyme. The immobilization of biomolecules inside the nanopore leads to the reduction of the available area for ionic transport, and this blocking effect can be exploited to tune the conductance and selectivity of the nanopore in aqueous solution. Both cylindrical and conical nanopores were used in the experiments. The possibility of obtaining two or more conductance states (output), dictated by the degree of nanopore blocking resulted from the different biomolecules in solution (input), as well as the current rectification properties obtained with the conical nanopore, could also allow implementing information processing at the nanometre scale. Model simulations based on the transport equations further verify the feasibility of the sensing procedure that involves concepts from supramolecular chemistry, molecular imprinting, recognition, and nanotechnology.     

Preparation and characterization of aluminum oxide–poly(ethylene-co-butyl acrylate) nanocomposites

This article describes the preparation and characterization of composites containing poly(ethylene-co-butyl acrylate) (EBA–13 and EBA–28 with 13 and 28 wt % butyl acrylate, respectively) and 2–12 wt % (0.5–3 vol %) of aluminum oxide nanoparticles (two types differing in specific surface area and hydroxyl-group concentration; uncoated and coated with, respectively, octyltriethoxysilane and aminopropyltriethoxysilane). A greater surface coverage was obtained with aminopropyltriethoxysilane than with octyltriethoxysilane. An overall good dispersion was obtained in the EBA-13 composites prepared by extrusion compounding. Composites with octyltriethoxysilane-coated nanoparticles showed the best dispersion. The addition of the nanoparticles to EBA–28 resulted in poor dispersion, probably due to insufficiently high shear forces acting during extrusion mixing which were unable to break down nanoparticle agglomerates. The nanoparticles had no effect on the crystallization kinetics in the EBA–13 composites, but in the EBA–28 composites the presence of the nanoparticles led to an increase in the crystallization peak temperature, suggesting that the nanoparticles had a nucleating effect in this particular polymer. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012