Automated oral cancer identification using histopathological images: a hybrid feature extraction paradigm

Oral cancer (OC) is the sixth most common cancer in the world. In India it is the most common malignant neoplasm. Histopathological images have widely been used in the differential diagnosis of normal, oral precancerous (oral sub-mucous fibrosis (OSF)) and cancer lesions. However, this technique is limited by subjective interpretations and less accurate diagnosis. The objective of this work is to improve the classification accuracy based on textural features in the development of a computer assisted screening of OSF. The approach introduced here is to grade the histopathological tissue sections into normal, OSF without Dysplasia (OSFWD) and OSF with Dysplasia (OSFD), which would help the oral onco-pathologists to screen the subjects rapidly. The biopsy sections are stained with H&E. The optical density of the pixels in the light microscopic images is recorded and represented as matrix quantized as integers from 0 to 255 for each fundamental color (Red, Green, Blue), resulting in a M×N×3 matrix of integers. Depending on either normal or OSF condition, the image has various granular structures which are self similar patterns at different scales termed "texture". We have extracted these textural changes using Higher Order Spectra (HOS), Local Binary Pattern (LBP), and Laws Texture Energy (LTE) from the histopathological images (normal, OSFWD and OSFD). These feature vectors were fed to five different classifiers: Decision Tree (DT), Sugeno Fuzzy, Gaussian Mixture Model (GMM), K-Nearest Neighbor (K-NN), Radial Basis Probabilistic Neural Network (RBPNN) to select the best classifier. Our results show that combination of texture and HOS features coupled with Fuzzy classifier resulted in 95.7% accuracy, sensitivity and specificity of 94.5% and 98.8% respectively. Finally, we have proposed a novel integrated index called Oral Malignancy Index (OMI) using the HOS, LBP, LTE features, to diagnose benign or malignant tissues using just one number. We hope that this OMI can help the clinicians in making a faster and more objective detection of benign/malignant oral lesions.     

Quantum dot bio-conjugate: as a western blot probe for highly sensitive detection of cellular proteins

In the present study, we report a quantum dot (QD)-tailored western blot analysis for a sensitive, rapid and flexible detection of the nuclear and cytoplasmic proteins. Highly luminescent CdTe and (CdTe)ZnS QDs are synthesized by aqueous method. High resolution transmission electron microscopy, Raman spectroscopy, fourier transform infrared spectroscopy, fluorescence spectroscopy and X-ray diffraction are used to characterize the properties of the quantum dots. The QDs are functionalized with antibodies of prostate apoptosis response-4 (Par-4), poly(ADP-ribose) polymerases and β actin to specifically bind with the proteins localized in the nucleus and cytoplasm of the cells, respectively. The QD-conjugated antibodies are used to overcome the limitations of conventional western blot technique. The sensitivity and rapidity of protein detection in QD-based approach is very high, with detection limits up to 10 pg of protein. In addition, these labels provide the capability of enhanced identification and localization of marker proteins in intact cells by confocal laser scanning microscopy.     

Vanillin Phosphorescence as a Probe of Molecular Mobility in Amorphous Sucrose

Changes in molecular mobility are important in defining the stability and quality of amorphous solid foods, pharmaceuticals, and other solid biomaterials. Predictions of stability must consider matrix mobility below and above T_g (the glass transition temperature); measurement of molecular mobility in amorphous solids over time scales ranging from <10⁻⁹ s to >10⁸ s requires specialized methods. This research investigated how the steady-state and time-resolved emission and intensity of phosphorescence from vanillin (4-hydroxy-3-methoxy benzaldehyde), a common flavor compound, can be used to probe molecular mobility when dispersed within amorphous pure sucrose films. Phosphorescence emission spectra and time-resolved intensity decays, measured in sucrose as a function of temperature in the absence of oxygen, were strongly modulated by matrix molecular mobility. Temperature had a significant effect on vanillin phosphorescence peak frequency and bandwidth, intensity, and lifetime both in the glass and in the melt. Time-resolved phosphorescence intensity decays from vanillin were multiexponential both below and above the glass transition temperature, indicating that the pure (single component) amorphous matrix was dynamically heterogeneous on the molecular level. These data show that vanillin is a promising intrinsic probe of molecular mobility and dynamic heterogeneity in amorphous solid foods and perhaps pharmaceuticals.     

Dose-dependent optically stimulated luminescence of synthetic quartz at room temperature

Physical conditions such as annealing temperature, duration of annealing, ionizing radiation, etc., play a significant role in the applications of optically stimulated luminescence (OSL) dating as well as OSL dosimetry. Many efforts are made to understand the effect of these physical parameters on quartz specimens owing to its use in such applications. Such factors induce changes in OSL decay pattern. The definite correlation between color centers and luminescence sensitivity can be established on account of such pre-treatments to the specimen.The purpose of present investigations is to study the effect of ionizing radiation under identical physical conditions on OSL properties measured at room temperature. The shapes of decay curve and dose-response data are considered for this purpose. This study can reveal the changes in color centers in response to the pre-conditions to the specimen. It was found that the OSL decay remains slow and OSL properties change systematically with the rise in beta dose up to a critical dose; however, it changes the pattern when the beta exposure to the specimen was increased higher than the critical dose. This critical dose was found to be different for different temperature of annealing. The shape of decay curve up to the critical dose was also studied by considering the difference of OSL intensities between two successive durations from the observed OSL decay data. The results are explained based on the changes in available shallow traps during OSL measurement at room temperature with changes in pre-conditions to the specimens. The results also have been confirmed with the corresponding changes in ESR signals.     

Nanostructured microspheres of silver @ zinc oxide: an excellent impeder of bacterial growth and biofilm

Au@TiO₂ core–shell hollow nanoparticles were prepared by a simple hydrothermal method without surfactants or templates. The core–shell structure materials were characterized by transmission electron microscopy, X-ray powder diffraction, scanning electron microscopy, and specific surface area of the test (BET). The catalytic activity was tested in a stainless reactor with a fixed bed and connected with a gas chromatograph. The results show that the microstructure, crystallography, and morphology were correlated with the hydrothermal reaction time and temperature, and the properties of the solvent. The crystallinity degree of TiO₂ and the particle size increased with the reaction time and temperature. Particles with different morphologies can be obtained when using different solvents. The size of microsphere can be controlled easily by changing the amount of TiF₄. This material exhibited the complete CO conversion temperature to be about 130 °C and no deactivation was observed after 1,000 min reaction.     

Condensed Heterotricycles. Synthesis and Reactions of b-Fused 1(2H)-Isoquinolinones with unusual enaminic properties

Homophthalic acid ( 1 ) undergoes reaction with 1,2-, 1,3-, and 1,4-diamines to give condensed 1(2H)-isoquinolinones like 2 , 4 , 13 , and 25 , which exhibit marked enamine character. These are attacked by electrophiles at the N or C terminus. Some notable reactions of imidazoisoquinolone 2 are those with maleic and acrylic acids to form the tetracycles 48 and 51 , respectively. With propiolic acid, 5 underwent an interesting reaction to form the benzimidazonaphthyridine 53 . An equally interesting behaviour was elicited from 2 in its reaction with formaldehyde, when in addition to the expected methylene-bridged molecule 59 , the novel spiro derivative 60 was formed by the dimerisation of a presumed azadiene intermediate 63 .     

Phase relations in Cu- RO1.5- O (R < Ho,Er, Yb) and gibbs energy of formation of Cu2R2O5 (R < Ho,Er, Yb) between 1000 and 1325K

Phase relations in Cu-RO_1.5-O(R < Ho,Er,Yb) ternary systems at 1273K have been established by isothermal equilibration of samples containing different ratios of Cu:R(R < Ho,Er,Yb) in flowing air or high purity argon atmosphere for four days. The samples were then rapidly cooled to ambient temperature and the coexisting phases were identified by powder x-ray diffraction analysis. Only one ternary oxide, Cu₂R₂O₅(R < Ho,Er,Yb) was found to be stable. The chemical potential of oxygen for the coexistence of the three phase assemblage, Cu₂O + R₂O₃ + Cu₂R₂O₅(R < Ho,Er,Yb) has been measured by employing the solid-state galvanic cells,< (−) Pt, Cu₂O + Ho₂O₃+ Cu₂Ho₂O₅//CSZ//Air (Po₂< 2.12 × 10⁴ Pa), Pt (+) (−) Pt, Cu₂O + Er₂O₃+ Cu₂Er₂O//CSZ//Air (Po₂< 2.12 × 10⁴ Pa), Pt (+) (−) Pt, Cu₂O + Yb₂O₃ + Cu₂Yb₂O₅//CSZ//Air (Po₂ < 2.12 × 10⁴ Pa), Pt (+) in the temperature range of 1000 to 1325K. Combining the measured emf of the above cells with the chemical potential of oxygen at the reference electrode, using the Nernst relationship, gives for the reactions, 2Cu₂O(s) + 2Ho₂O₃(s) + O₂(g) → 2Cu₂Ho₂O₅(s) (1) 2Cu₂O(s) + 2Er₂O₃(s) + O₂(g) → 2Cu₂Er₂O₅(s) (2) and 2Cu₂O(s) + 2Yb₂O₃(s) + O₂(g) → 2Cu₂Yb₂O₅(s) (3) δΜo₂ = −219,741.3 + 145.671 T (±100) Jmol⁻¹ (4) δΜo₂ = −222,959.8 + 147.98 T(±100) Jmol⁻¹ (5) and δΜo₂ = −231,225.2 + 151.847 T(±100) Jmol⁻¹ (6) respectively. Combining the chemical potential of oxygen for the coexistence of Cu₂O + R₂O₃ + Cu₂R₂O₅(R− Ho,Er,Yb) obtained in this study with the oxygen potential for Cu₂O + CuO equilibrium gives for the reactions, 2 CuO(s) + Ho₂O₃(s) → Cu₂Ho₂O₅(s) (7) 2 CuO(s) + Er₂O₃(s) → Cu₂Er₂O₅(s) (8) and 2 CuO(s) + Yb₂O₃(s) → Cu₂Yb₂O₅(s) (9) δG‡ < 22,870.3 − 23.160 T (±100) Jmol⁻¹ (10) δG‡ < 21,261.1 − 22.002 T (±100) Jmol⁻¹ (11) and δG‡ < 17,128.4 - 20.072 T (±100) Jmol^-1 (12) It can be clearly seen that the formation of Cu₂R₂O₅R < Ho,Er,Yb) from the component oxides is endothermic. Further, Cu₂R₂O₅(R < Ho,Er,Yb) are an entropy stabilized phases. Based on the results obtained in this study, the oxygen potential diagram for Cu-R-O(R < Ho,Er,Yb) ternary system at 1273K has been composed.     

Coefficient sensitivity of state-space digital filters derivedusing balanced model truncation

The issue of coefficient sensitivity in digital filters derived using the technique of balanced model truncation is investigated. It is known that balanced systems have minimal sensitivity and we present some simulation results which show that subsequent truncation generates only a negligible deviation from this minimum. This is a desirable situation when designing reduced-order state-space digital filters