Downstream targets of methyl CpG binding protein 2 and their abnormal expression in the frontal cortex of the human Rett syndrome brain

Background  

The Rett Syndrome (RTT) brain displays regional histopathology and volumetric reduction, with frontal cortex showing such abnormalities, whereas the occipital cortex is relatively less affected.     

Synthesis and characterization of novel styryl-substituted oligothienylenevinylenes

A number of 3-monosubstituted bis(thienylvinyl)thiophenes, suitable for the preparation of electronically-variable poly(thienylenevinylene)s have been synthesized for the first time. These materials have been characterized by both NMR spectroscopy and mass spectrometry, and a single crystal X-ray structure analysis of (E,E)-3-(5,5-dimethyl[1,3]dioxin-2-yl)-2,5-bis(2-thien-2-ylvinyl)thiophene has shown that the planarity of the terthienylenevinylene chain is maintained on substitution at the 3 position of the central thiophene ring. UV/visible spectroscopy measurements are reported and cyclic voltammetric measurements show that, with the exception of (E,E,E)-2,5-bis(2-thien-2-ylvinyl)-3-(2-(4-dimethylaminophenyl)vinyl)-thiophene, electroactive films are produced on electrochemical oxidation of the monomers.     

Spectrophotometric determination of zirconium in steels with xylenol orange

Zirconium (0.005–0.25%) is determined after acid dissolution of the steel, and fusion of insoluble matter with sodium carbonate and sodium hydrogensulphate. Niobium and other interfering ions are removed by mercury cathode electrolysis. Residual small amounts of iron(III) are masked with ascorbic acid.     

Immiscible electrolyte systems based on asymmetric hydrophobic room temperature ionic liquids

The effect on the melting point of the introduction of asymmetry in tetraalkylammonium halide salts has been investigated leading to the synthesis of new, hydrophobic (room temperature) ionic liquids suitable for liquid/liquid electrochemistry; one of these, tri(hexyl)decylammonium tetrakis(pentafluorophenyl)borate, displays the largest electrochemical window observed to date for a biphasic room temperature ionic liquid system.     

On Coprimality Graphs for Symmetric Groups

For G a group, X a subset of G and π a set of positive integers we define a graph ${\mathcal{C}_{\pi}(G,X)}$ whose vertex set is X with ${x,y \in X}$ joined by an edge provided x ≠ y and the order of xy is in π. Here we investigate ${\mathcal{C}_{\pi}(G,X)}$ when G is a finite symmetric group and X is a G-conjugacy class of elements of order p, p a prime.     

Synthetic studies toward phenoxan analogs

We developed two reactions needed for a total synthesis of phenoxan, a naturally occurring compound with anti-HIV activity. In this Note, we further examined these two issues: metallation of a 2-methyl-oxazole and formation of a pyran-4-one. We employed these methods for the preparation of a phenoxan analog.     

Superior analytical sensitivity of electromagnetic excitation compared to contact electrode instigation of transverse acoustic waves

Quartz disks incorporated into an electrolyte flow-through configuration have been excited by both direct electrode contact and electromagnetic fields to generate propagating transverse acoustic waves in to the fluid. The conventional thickness-mode device was operated at the first harmonic (9 MHz) whereas the EM excited structure functioned successfully at 453 MHz (nominal 49th harmonic). The nature of signals produced by the two devices and potential contributions to noise are evaluated. A comparison of the response of the higher frequency sensor to the introduction of the protein neutravidin to the system reveals at least a seven times higher signal-to-noise ratio than is the result for the conventional bulk-acoustic wave structure. This increase in sensitivity coupled with the possibilities for tuning the frequency of the electromagnetic device and its potential for non-contact excitation offer significant advantages in terms of analytical sensor technology.     

Surface properties and electromagnetic excitation of a piezoelectric gallium phosphate biosensor

The surface properties of GaPO4 have been studied by secondary ion mass spectrometry, X-ray photoelectron spectroscopy and electromagnetic acoustic wave excitation in order to explore the potential of this relatively new piezoelectric material as a biosensor. The X-ray photoelectron spectrum of the substrate shows a Ga-rich surface (Ga:P = 1.4), while the negative secondary ion mass spectrum is similar to that of other phosphates, with PO3- and PO2- being the main fragments derived from the substrate. Surface analysis reveals that the linker protein for biotinylated moieties, neutravidin, is both readily chemisorbed to bare gallium phosphate at pH 7.5 and attached to p-hydroxy benzaldehyde-treated devices, establishing the possibility to exploit the surface chemistry of the phosphate for the fabrication of an electrode-free acoustic wave biosensor. Preliminary results regarding the detection of the adsorption of neutravidin with an electromagnetic field-excited GaPO4 device incorporated in a FIA configuration showed comparable results with those obtained with a quartz-sensor equivalent. The frequency shift for the adsorbed protein layer at the device fundamental frequency was 200 Hz and the noise was routinely around 13 Hz. The possibility to use the electrodeless acoustic GaPO4 device at higher harmonics in the liquid phase has also been confirmed.     

Determining restriction digest efficiency using the SNaPshot single-base extension method and CE

Incomplete restriction endonuclease digestion may cause complications during particular applications, where any undigested product may interfere with genotyping accuracy, cloning efficiency or PCR amplification. In some instances it may be useful to measure the amount of undigested DNA remaining in the sample, allowing redigestion or elimination of unsuitable samples. A single-base extension SNP genotyping method (SNaPshot, Applied Biosytems) was adapted to interrogate restriction sites and their digestibility. The digested DNA was amplified by nested PCR to specifically amplify sections containing the restriction sites of interest. Single interrogation primers, terminating immediately 5' of the cleavage site, were used in conjunction with the SNaPshot multiplex system and CE to detect intact, amplifiable product remaining in the digest. This method detected as little as 10 pg of intact DNA, within a larger proportion of digested DNA. Across two different restriction enzymes, the amount remaining undigested was found to be dependent on the amount of DNA, ranging from 0.08% with 200 ng to 1.25% with 600 ng.