KIT Expression Is Regulated by DNA Methylation in Uveal Melanoma Tumors

Uveal melanoma (UM) is an ocular tumor with a dismal prognosis. Despite the availability of precise molecular and cytogenetic techniques, clinicopathologic features with limited accuracy are widely used to predict metastatic potential. In 51 UM tissues, we assessed a correlation between the expression of nine proteins evaluated by immunohistochemistry (IHC) (Melan-A, S100, HMB45, Cyclin D1, Ki-67, p53, KIT, BCL2, and AIFM1) and the presence of UM-specific chromosomal rearrangements measured by multiplex ligation-dependent probe amplification (MLPA), to find IHC markers with increased prognostic information. Furthermore, mRNA expression and DNA methylation values were extracted from the whole-genome data, achieved by analyzing 22 fresh frozen UM tissues. KIT positivity was associated with monosomy 3, increasing the risk of poor prognosis more than 17-fold (95% CI 1.53–198.69, p = 0.021). A strong negative correlation was identified between mRNA expression and DNA methylation values for 12 of 20 analyzed positions, five located in regulatory regions of the KIT gene (r = −0.658, p = 0.001; r = −0.662, p = 0.001; r = −0.816; p < 0.001; r = −0.689, p = 0.001; r = −0.809, p < 0.001, respectively). DNA methylation β values were also inversely associated with KIT protein expression (p = 0.001; p = 0.001; p = 0.015; p = 0.025; p = 0.002). Our findings, showing epigenetic deregulation of KIT expression, may contribute to understanding the past failure to therapeutically target KIT in UM.     

The polymerization mechanism of lactide initiated with zinc (II) acetylacetonate monohydrate

The paper presents the mechanism of lactide polymerization initiated with zinc (II) acetylacetonate monohydrate. However, the actual initiator of this reaction is the complex containing a metal-oxygen bond, formed by the exchange reaction of acetylacetonate ligand with deprotonated lactide derivative. The described reaction results in the release of free acetylacetonate and formation of transitional zinc complex with metal-oxygen bond connecting the zinc atom with derivative of lactide, incorporated - as a new, active in polymerization ligand. Polylactide chain propagation process, which constitutes the following stage of the reaction, is caused by a typical, well known, coordination-insertion ring opening polymerization. The proceeding polymerization maximum yield at the applied conditions does not exceed about 70% in benzene solution and 90% at bulk.     

Optical and electrochemical properties of thermostable polymers containing light‐emitting units

Two series of polymers and copolymers containing oxadiazole units have been studied with respect to their photo‐optical and electrochemical behavior. Fluorene units were introduced in the macromolecular chain together with oxadiazole rings in order to obtain a better balance between electrons and holes injection and transporting properties. Upon irradiation with UV light the polymers showed photoluminescence maxima in the blue spectral range. Cyclic voltammetry was performed in order to obtain information about the electrochemical stability and reversibility of the redox processes of these polyoxadiazoles. The highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels, and electrochemical and optical band gap values were calculated by using the results of cyclic voltammetry and UV/vis spectroscopy, respectively, showing very good electron injection and transport characteristics. POLYM. ENG. SCI., 54:1126–1133, 2014. © 2013 Society of Plastics Engineers     

The amine modified acrylic copolymers as catalysts in the reaction of octylbromide with sodium cyanide

Summary Amine-modified and alkylated (with butyl bromide or hexyl bromide) acrylonitrile-butyl acrylate-divinylbenzene terpolymers and alkyl acrylate-divinylbenzene copolymers (where alkyl=methyl, ethyl or butyl) were used as catalysts in the reaction of octyl bromide with cyanide anions. The dependence of catalytic activity as a function of the acrylate content and swelling properties was investigated. The most effective catalyst was butyl acrylate-divinylbenzene copolymer. This sample showed maximum toluene uptake from the toluene/water mixture.     

A study of thermal,optical and electrical properties of new branched triphenylamine-based polyazomethines

A series of branched aromatic polyazomethines have been obtained by high temperature solution polycondensation of 4,4′,4″-triformyltriphenylamine with 3,3′-dimethoxybenzidine with different feed molar ratio. For three polymers additional condensation of chain end groups with monofunctional monomers such as 4-formyltriphenylamine or 2-naphthylamine was carried out. Moreover, two model compounds were prepared and investigated for comparison with branched polymers. The structures of polymers and models were characterized by means FTIR, ¹H, ¹³C NMR spectroscopy, elemental analysis and gel permeation chromatography (GPC). UV–vis properties of the thin films of the polymers and compounds were investigated on the glass substrate. Eg of the branched polymers was found about 2.47 eV. UV–vis and FTIR spectroscopy for iodine doped compounds were investigated. Doping decreased the value of Eg of the branched polyazomethines to about 1.71 eV. Refractive index (n) for branched polyazomethines was found about 1.97, while for the doped compounds was a little higher (～2.48). Absorption (UV–vis) properties of the doped with iodine branched imines were investigated additionally after heating in different temperatures from 50 to 200 °C. Intensity of photoluminescence of branched imines in relation to 9,10-diphenylanthracene was found in the range 0.2–1.0% and 2.7–43.7% in dependence on the excitation wavelengths. Current–voltage (I–V) measurements were performed on ITO/TiO₂/polymer/Al, ITO/polymer/Alq₃/Al and ITO/TiO₂/polymer/Alq₃/Al devices in the dark and during irradiation with light (under illumination 1000 W/m²). The sol–gel technique was applied to prepared TiO₂ layer. TiO₂ layers and devices were investigated by Atomic Force Microscopy (AFM). Moreover, properties of these branched polymers were compared with the linear polyazomethine based on 3,3′-dimethoxybenzidine and 4,4′-diformyltriphenylamine.     

Intelligent Processing of Stuttered Speech

The process of counting stuttering events could be carried out more objectively through the automatic detection of stop-gaps, syllable repetitions and vowel prolongations. The alternative would be based on the subjective evaluations of speech fluency and may be dependent on a subjective evaluation method. Meanwhile, the automatic detection of intervocalic intervals, stop-gaps, voice onset time and vowel durations may depend on the speaker and the rules derived for a single speaker might be unreliable when trying to consider them as universal ones. This implies that learning algorithms having strong generalization capabilities could be applied to solve the problem. Nevertheless, such a system requires vectors of parameters, which characterize the distinctive features in a subject's speech patterns. In addition, an appropriate selection of the parameters and feature vectors while learning may augment the performance of an automatic detection system.The paper reports on automatic recognition of stuttered speech in normal and frequency altered feedback speech. It presents several methods of analyzing stuttered speech and describes attempts to establish those parameters that represent stuttering event. It also reports results of some experiments on automatic detection of speech disorder events that were based on both rough sets and artificial neural networks.     

Intelligent video and audio applications for learning enhancement

The role of computers in school education is briefly discussed. Multimodal interfaces development history is shortly reviewed. Examples of applications of multimodal interfaces for learners with special educational needs are presented, including interactive electronic whiteboard based on video image analysis, application for controlling computers with facial expression and speech stretching audio interface representing audio modality. Intelligent and adaptive algorithms applications to the developed multimodal interfaces are discussed.     

Phase formations during mechanochemical synthesis of PbTiO<Subscript>3</Subscript>

Lead titanate nanopowders were fabricated by mechanochemical synthesis from lead oxide and titanium dioxide. The milling process has been carefully investigated by X-ray diffraction and X-ray excited photoelectron spectroscopy. The first traces of perovskite phase were detected after 5 h synthesis. It was found that intermediated phases (Ti₁₀O₁₈ and Pb₃O₄) have been formed at the early stage of synthesis. The 50 h milling results in single perovskite phase with average crystallite size of 20 nm.