Chemical abscess post vein of Galen aneurysmal malformation embolisation with ethylene vinyl alcohol copolymer.

Unlabelled: Vein of Galen aneurysmal malformation (VGAM) is a rare congenital malformation characterised by arteriovenous fistulas between primitive choroidal arteries and the median prosencephalic vein, the embryonic precursor to the vein of Galen. Endovascular techniques have changed the management of these patients with improved prognosis. An eight-month-old with VGAM managed by endovascular embolisation using ethylene vinyl alcohol copolymer (EVOH) developed a chemical abscess - a rare complication.

Rational design and synthesis of novel triazole- and tetrazole-fused iminosugars as potential inhibitors of amyotrophic lateral sclerosis (ALS) linked SOD1 aggregation.

In this manuscript we report the first example of an iminosugar that inhibits superoxide dismutase fibrillation associated with the amyotrophic lateral sclerosis (ALS). The present work involves synthesis of novel triazole and tetrazole embedded iminosugars, synthesized in 11-13 high yielding steps starting from readily available tri-O-benzyl-D-glucal and proceeding through a concomitant azidation - thermal intramolecular [3 + 2] cycloaddition reaction as the key step. One of these pre-designed iminosugars was found to inhibit fibrillation of SOD1 and also has shown propensity to break pre-formed fibrils.

An expeditious synthesis of novel DNA nucleobase mimics of (+)-anisomycin.

A glycal based expeditious synthesis of novel nucleoside analogues of (+)-anisomycin is reported. Readily available tri-O-benzyl-D-glucal was converted to a partially protected trihydroxypyrrolidine that is used as a common scaffold for the introduction of various nucleobases at the primary hydroxyl centre. Nucleoside analogues possessing all four DNA bases have been synthesized.

Effects of surface oxidation on the pH-dependent surface charge of oxidized aluminum gallium nitride.

Hypothesis: The properties of the oxidized surface for common materials, such as silicon and titanium, are known to be markedly different from the reduced surface. We hypothesize that surface-oxidized aluminum gallium nitride ((oxidized-AlGaN)/GaN) surface charge behavior is different to unoxidized AlGaN (with ultrathin native oxide only), which can be validated via surfactant adsorption. Understanding these differences will explain why (oxidized-AlGaN)/GaN-based sensors are better performing than AlGaN ones, which has been previously demonstrated but not understood.

Supramolecular Architecture through Self-Organization of Janus-Faced Homoazanucleosides.

Design of Janus-faced or double-headed homoazanucleosides with the possibility to undergo self-organization through base pairing has been conceptualized and accomplished. The synthetic strategy demonstrates the unique ability to introduce two similar or complementary nucleobases on opposite arms of a chiral polyhydroxypyrrolidine while also ensuring that their faces are anti to each other to allow only intermolecular interactions between the nucleobases, an essential requisite for self-assembly. Single-crystal X-ray structures were determined for all three types of homoazanucleosides, one possessing two adenine molecules, the other with two thymine moieties, and the third containing both adenine and thymine.

pH-Dependent surface charge at the interfaces between aluminum gallium nitride (AlGaN) and aqueous solution revealed by surfactant adsorption.

Hypothesis: The net surface charge of AlGaN/GaN structures, where AlGaN is in contact with the solution, is controlled by the pH-dependent protonation and deprotonation of the surface hydroxyl groups and possibly the electron-deficient surface electronic states. We hypothesize that atomic force microscopy (AFM) force measurements of ionic surfactant adsorption can reveal how the AlGaN surface properties vary with pH.

Experiments: AFM force curves and images were used to probe the AlGaN/solution interface in water as a function of pH, and with added cationic surfactant cetyltrimethylammonium bromide (CTAB) or anionic surfactant sodium dodecylsulfate (SDS).

A glycal based approach to the synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-one.

A glycal based synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-ones proceeding through a common intermediate is reported. The key step in the work presented here is a two-step conversion of 4,6-di-O-benzyl-d-glucal to 2,3-dideoxy-2-tosylamido-d-glucose. This manuscript reports the first carbohydrate based approach to the synthesis of (+)-bulgecinine and the whole sequence has been accomplished with complete stereochemical integrity without the formation of mixture of products in any of these steps.

pH-dependent surface properties of the gallium nitride - Solution interface mapped by surfactant adsorption.

Hypothesis: The surface charge of gallium nitride (GaN) in contact with solution is controlled by pH via surface protonation and deprotonation, similar to silica. Ionic surfactants adsorb on surfaces via electrostatic and hydrophobic interactions and can be utilized to reflect the surface charge of GaN.

Experiments: The surface charge properties of Ga-polar GaN in solution were probed as a function of pH using atomic force microscopy (AFM).

Ca detection utilising AlGaN/GaN transistors with ion-selective polymer membranes.

We demonstrate highly selective and sensitive potentiometric ion sensors for calcium ion detection, operated without the use of a reference electrode. The sensors consist of AlGaN/GaN heterostructure-based transistor devices with chemical functionalisation of the gate area using poly (vinylchloride)-based (PVC) membranes having high selectivity towards calcium ions, Ca. The sensors exhibited stable and rapid responses when introduced to various concentrations of Ca.

Origin of defect-insensitive emission probability in In-containing (Al,In,Ga)N alloy semiconductors.

Group-III-nitride semiconductors have shown enormous potential as light sources for full-colour displays, optical storage and solid-state lighting. Remarkably, InGaN blue- and green-light-emitting diodes (LEDs) emit brilliant light although the threading dislocation density generated due to lattice mismatch is six orders of magnitude higher than that in conventional LEDs. Here we explain why In-containing (Al,In,Ga)N bulk films exhibit a defect-insensitive emission probability.