Surface roughness detection of arteries via texture analysis of ultrasound images for early diagnosis of atherosclerosis

There is a strong research interest in identifying the surface roughness of the carotid arterial inner wall via texture analysis for early diagnosis of atherosclerosis. The purpose of this study is to assess the efficacy of texture analysis methods for identifying arterial roughness in the early stage of atherosclerosis. Ultrasound images of common carotid arteries of 15 normal mice fed a normal diet and 28 apoE−/− mice fed a high-fat diet were recorded by a high-frequency ultrasound system (Vevo 2100, frequency: 40 MHz). Six different texture feature sets were extracted based on the following methods: first-order statistics, fractal dimension texture analysis, spatial gray level dependence matrix, gray level difference statistics, the neighborhood gray tone difference matrix, and the statistical feature matrix. Statistical analysis indicates that 11 of 19 texture features can be used to distinguish between normal and abnormal groups (p<0.05). When the 11 optimal features were used as inputs to a support vector machine classifier, we achieved over 89% accuracy, 87% sensitivity and 93% specificity. The accuracy, sensitivity and specificity for the k-nearest neighbor classifier were 73%, 75% and 70%, respectively. The results show that it is feasible to identify arterial surface roughness based on texture features extracted from ultrasound images of the carotid arterial wall. This method is shown to be useful for early detection and diagnosis of atherosclerosis.Lili Niu, Ming Qian, Wei Yang, Long Meng, Yang Xiao, Kelvin K. L. Wong, Derek Abbott, Xin Liu, Hairong Zhen

Raman Spectra of In0.30\text{}_{0.30}Se0.70\text{}_{0.70} Amorphous Films

Amorphous films of In$\text{}_{0.30}$Se$\text{}_{0.70}$ alloy thermally evaporated from one source onto borosilicate glass substrates were studied by Raman scattering at 300K and 10K. The Raman scattering spectra excited with 488 and 457.9nm laser lines were recorded in a quasi-rectangular geometry with the use of a single channel spectrometer. All the Raman scattering spectra reveal a continuum spreading from the Rayleigh line up to about 250cm$\text{}^{-1}$ and rather featureless background due to second-order processes beyond it. The room temperature spectra show a strong feature at about 143cm$\text{}^{-1}$ that is lacking in the spectra taken at 10K and, instead, a weak band at about 125cm$\text{}^{-1}$ is observed. The Raman scattering spectra recorded at both temperatures appear to be dependent on the excitation line within the 40-50cm$\text{}^{-1}$ range. The feature at about 143cm$\text{}^{-1}$ is attributed to Se chain modes while a weaker band at about 125cm$\text{}^{-1}$ observed at low temperature is due to Se$\text{}_{8}$ ring molecules. The dynamics of the In$\text{}_{0.30}$ Se$\text{}_{0.70}$ films is treated in terms of a continuous random network composed of rather strongly interconnected InSe$\text{}_{4}$ tetrahedral clusters

Studies of Optical Properties of Protonated Polyazomethine Thin Films

We report results of experimental studies supplemented with the first principles calculations aimed to explain influence of doping on electronic and optoelectronic properties of thin PPI films. It has been predicted theoretically and confirmed experimentally that chemical doping with the HCl acid vapor is thermally reversible process due to relatively low energy barrier for protonation

Stability of Diodes with Poly(3-hexylthiophene) and Polyazomethines Thin Organic Layer

Herein we report results of studies on stability of diodes based on organic semiconductors such as poly (3-hexylthiophene) (P3HT) and soluble derivative of polyazomethine poly(1,4-(2,5-bisoctyloxy phenylenemethylidynenitrilo)-1,4-phenylenenitrilomethylidyne), (BOO-PPI). Both polymers were deposited on glass/ITO substrate with or without covering with blocking layer: poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) and finished with Al back electrode. Prepared devices were studied by monitoring their electrical conductivity under nitrogen atmosphere and ambient air conditions. Under nitrogen atmosphere a marked influence of presence of the blocking layer on the diodes electrical conductivity was revealed. The P3HT diodes prepared without PEDOT:PSS thin film shown quick degradation, whereas presence of these layers stabilizes electrical conductivity in these devices. Inversely, the PPI based diodes without the PEDOT:PSS revealed stable conducting properties, while corresponding diodes with PEDOT:PSS layer showed degradation traces of their conducting properties

Stability of Diodes with Poly(3-hexylthiophene) and Polyazomethines Thin Organic Layer

Herein we report results of studies on stability of diodes based on organic semiconductors such as poly (3-hexylthiophene) (P3HT) and soluble derivative of polyazomethine poly(1,4-(2,5-bisoctyloxy phenylenemethylidynenitrilo)-1,4-phenylenenitrilomethylidyne), (BOO-PPI). Both polymers were deposited on glass/ITO substrate with or without covering with blocking layer: poly(3,4-ethylenedioxythiophene):poly(4-styrene sulfonate) (PEDOT:PSS) and finished with Al back electrode. Prepared devices were studied by monitoring their electrical conductivity under nitrogen atmosphere and ambient air conditions. Under nitrogen atmosphere a marked influence of presence of the blocking layer on the diodes electrical conductivity was revealed. The P3HT diodes prepared without PEDOT:PSS thin film shown quick degradation, whereas presence of these layers stabilizes electrical conductivity in these devices. Inversely, the PPI based diodes without the PEDOT:PSS revealed stable conducting properties, while corresponding diodes with PEDOT:PSS layer showed degradation traces of their conducting properties