Biometric-based cryptography for digital content protection without any key storage

Multimedia Tools and Applications - The traditional digital data security mechanisms follow either cryptography or authentication. The primary point of contention with these mechanisms remains...     

Thermoelastic interaction in the semi-infinite solid medium due to three-phase-lag effect involving memory-dependent derivative

The present study deals with the thermoelastic interaction in a semi-infinite elastic solid with a heat source in the context of three-phase-lag model with memory-dependent derivative. The governing coupled equations, involving time delay and kernel functions are expressed in the vector matrix differential equation form in the Laplace transform domain. The analytical formulations of the problem have been solved by eigenvalue technique. The Honig–Hirdes numerical method is used for the inversion of Laplace transformation. Numerical results are obtained by choosing various types of time delay parameters and kernel functions and graphical representations have been performed accordingly. An extrapolative capability is established by considering the memory-dependent derivative into a three-phase-lag model.     

Identification of a novel structure in heparin generated by sequential oxidative-reductive treatment

Unfractionated heparin is isolated from animal organs, predominantly porcine intestinal mucosa, and goes through an extensive process of purification before it can be used for pharmaceutical purposes. While the structural microheterogeneity of heparin is predominantly biosynthetically imprinted in the Golgi, subsequent steps involved in the purification and manufacture of commercial heparin can lead to the introduction of additional modifications. Postheparin crisis of 2008, it has become increasingly important to identify what additional structural diversity is introduced as a function of the purification process and thus can be determined as being heparin-related, as opposed to being an adulterant or contaminant, e.g., oversulfated chondroitin sulfate. Our study focuses on the identification of a previously unreported structure in heparin that arises due to specific steps used in the manufacturing process. This structure was initially observed as a disaccharide peak in a complete enzymatic digest of heparin, but its presence was later identified in the NMR spectra of intact heparin as well. Structural elucidation experiments involved isolation of this structure and analysis based on multidimensional NMR and liquid chromatography coupled with mass spectrometry (LC-MS). Heparin was also subjected to specific chemical reactions to determine which steps in the manufacturing process are responsible for this novel structure. Our results allowed for the definitive assignment of the structure of this novel process-related modification and enabled an identification of the putative steps in the process that give rise to the structure.     

Raman spectroscopy-based sensitive and specific detection of glycated hemoglobin

In recent years, glycated hemoglobin (HbA1c) has been increasingly accepted as a functional metric of mean blood glucose in the treatment of diabetic patients. Importantly, HbA1c provides an alternate measure of total glycemic exposure due to the representation of blood glucose throughout the day, including post-prandially. In this article, we propose and demonstrate the potential of Raman spectroscopy as a novel analytical method for quantitative detection of HbA1c, without using external dyes or reagents. Using the drop coating deposition Raman (DCDR) technique, we observe that the nonenzymatic glycosylation (glycation) of the hemoglobin molecule results in subtle but discernible and highly reproducible changes in the acquired spectra, which enable the accurate determination of glycated and nonglycated hemoglobin using standard chemometric methods. The acquired Raman spectra display excellent reproducibility of spectral characteristics at different locations in the drop and show a linear dependence of the spectral intensity on the analyte concentration. Furthermore, in hemolysate models, the developed multivariate calibration models for HbA1c show a high degree of prediction accuracy and precision--with a limit of detection that is a factor of ~15 smaller than the lowest physiological concentrations encountered in clinical practice. The excellent accuracy and reproducibility achieved in this proof-of-concept study opens substantive avenues for characterization and quantification of the glycosylation status of (therapeutic) proteins, which are widely used for biopharmaceutical development. We also envision that the proposed approach can provide a powerful tool for high-throughput HbA1c sensing in multicomponent mixtures and potentially in hemolysate and whole blood lysate samples.     

Treatment of textile effluent using bacteria-immobilized graphene oxide nanocomposites: evaluation of effluent detoxification using <Emphasis Type="Italic">Bellamya bengalensis</Emphasis>

Recent studies have reported graphene-based nanomaterials as novel scaffolds for the development of vigorous biocatalytic systems. The present study investigated polyacrylic acid-linked graphene oxide (GO)–gelatin nanocomposite for the immobilization of moderately halotolerant engineered bacterial consortium consisting of Dietzia sp., Bacillus sp. and Pseudomonas mendocina. This biocatalyst was subsequently applied for treatment of hypersaline textile effluents collected from local textile manufacturing and processing units. Effluent treatment efficiency of this biocatalyst was assessed in terms of its dye, surfactant and salt-removal abilities from collected effluents. High metabolic activity recorded in the case of immobilized bacterial cells indicated that immobilization had stimulated improved growth as well as electrolyte and pH tolerance in bacterial cells. Examination of the treated effluents suggested approximately 99% removal of COD, color (dyes), electrolytes and surfactant. Probable cyto-genotoxic potential and oxidative stress inducing the ability of both untreated and treated effluents was determined with Bellamya bengalensis (fresh water snail). Comet formation in hepatopancreatic cells of snails exposed to untreated effluent was significantly higher than in individuals exposed to treated effluents which in turn were similar to organisms treated as control. Hence, results of this study indicated efficient performance of GO-based biocatalyst in augmenting biodegradation and detoxification of textile effluent. The low cost incurred during the synthesis and application of bacteria-immobilized GO nanocomposite and its reusability potential determined herein established the process of effluent treatment reported in this study as a promising approach for commercial wastewater treatment.     

Simulation and experimental investigation of finishing forces in magnetic field assisted finishing process

Finishing forces in magnetic field assisted finishing process are normal force responsible for indentation and tangential force responsible for removal of indented materials. Analysis of finishing forces helps to understand the process mechanism and to control the process precisely. Simulation of finishing forces in magnetic field assisted finishing process is conducted using two finite element method based software packages. The experimental study confirms the simulation results as the difference between the obtained results from both the study is very small. A model is simulated for material removal using magnetorheological fluid having diamond abrasive particles on Ti alloy workpiece surface to predict material dislodgement during finishing. The significance of each process parameters is found out with the help of statistical analysis. The significant process parameters for normal force are abrasive volume concentration, working gap and carbonyl iron particle (CIP) volume concentration and for tangential force are tool rpm, working gap, and CIP volume concentration. It is perceived that the normal force rises with a surge in CIP concentration and reduction in abrasive concentration in MR fluid, working gap and tool rpm. The magnitude of tangential force rises with increased tool rpm, CIP concentration, abrasive concentration and decreased working gap.     

An approach to localize the retinal blood vessels using bit planes and centerline detection

The change in morphology, diameter, branching pattern or tortuosity of retinal blood vessels is an important indicator of various clinical disorders of the eye and the body. This paper reports an automated method for segmentation of blood vessels in retinal images. A unique combination of techniques for vessel centerlines detection and morphological bit plane slicing is presented to extract the blood vessel tree from the retinal images. The centerlines are extracted by using the first order derivative of a Gaussian filter in four orientations and then evaluation of derivative signs and average derivative values is performed. Mathematical morphology has emerged as a proficient technique for quantifying the blood vessels in the retina. The shape and orientation map of blood vessels is obtained by applying a multidirectional morphological top-hat operator with a linear structuring element followed by bit plane slicing of the vessel enhanced grayscale image. The centerlines are combined with these maps to obtain the segmented vessel tree. The methodology is tested on three publicly available databases DRIVE, STARE and MESSIDOR. The results demonstrate that the performance of the proposed algorithm is comparable with state of the art techniques in terms of accuracy, sensitivity and specificity.