The design and development of computer aided diagnosis (CAD) systems is done based on the features extracted from medical images. It will be appropriate to combine the information obtained from different images for better diagnosis. Diagnosis capability of ultrasound elastography and echography are analysed using the images obtained from tissue mimicking phantoms and patient images. The results of this analysis can be used to select the feature set for the design of CAD system for the diagnosis of solid lesions. Ultrasound B mode and elastography images were obtained from the commercial available scanner. Parameters are extracted from the analysis of these images.

Many ailments and/or malfunctions of the body have been observed to change the viscous behavior and elastic properties of biological soft tissues. The technique of elastography has evolved to image such properties. The clinical evidence gathered during studies involving elastography to identify cancerous lesions is very promising. However, the quantification of the resolution and specificity of elastography is best achieved under a controlled study using tissue-mimicking phantoms. One challenge is to reproduce viscoelastic behavior in phantoms as observed in biological tissues. In this paper, polyacrylamide gel based tissue-mimicking phantoms have been developed to experimentally study the role of viscoelastic properties in a controlled manner. To measure the Young's modulus, the phantoms were subjected to linear loading, and the stress-strain relationship is deduced therefrom. It is seen that the phantoms show hysteresis behavior. The viscoelastic properties of these phantoms were measured by subjecting the samples to cyclic loading. Normal forces during this process of loading were also measured as a measure of sample elasticity. To emulate the normal and pathological lesions, samples were prepared with varying concentration of monomer and studied. Three models, namely, Maxwell, Kelvin-Voigt (KV), and Kelvin-Voigt fractional derivative (KVFD), were chosen to fit the experimental data. Of these, the KVFD model was found to be best fitting for the experimental data obtained. Results indicate that stiffer samples exhibit large variations in the storage modulus when the precompression levels are altered.

The principal component of the amyloid deposits in Alzheimer’s disease is the β-amyloid polypeptide, while in type II diabetes the deposits consist primarily of Islet amyloid polypeptide. These amyloid forming polypeptides consist of highly polymorphic domains, which take different conformations including random coil, helical and β strand depending upon the microenvironment. We have studied major fibril-forming components of IAPP and βAP and demonstrated that conformational polymorphism of these peptides in different microenvironments correlate with cellular toxicity and proteasomal inhibitory activity. On treating with trifluoroethanol (TFE) the peptide fragments undergo structural transition from a random coil to a helical conformation. Even though these domains share the same gross amyloid structural characteristic, their proteasomal activities differ. We found that even the tetrapeptides have significant proteasomal inhibitory activity indicating that the amyloid formation is involved in the enhanced life of the smaller aggregates of full-length and fragment peptides, which could explain the toxicity of these sequences.

The molecular mechanism of the stabilization of collagen with hydrolyzable tannin, corilagin, has been investigated using techniques like centrifugation, shrinkage temperature, infrared spectroscopy, and differential scanning calorimetry. Thermodynamic measurements were also carried out for the collagen–corilagin interaction. Results of this study indicate the enthalpic nature of non-specific binding of collagen with corilagin. The shrinkage temperature increases linearly with corilagin, indicating that the helix–to–coil transition is hindered by corilagin interaction with collagen triple helix. This study suggests that ingested polyphenols (corilagin) alter the stability of the proline-rich protein in the gut. Thereby, the stability of collagen present in the serosa layer may be hindered.

Conductometry, circular dichroism and fluorescence spectroscopy are thetechniques employed to investigate the effect of added calcium ions and other monovalent and divalent metal ions on aqueous solutions of nonionic peptide aggregates, Boc-Leu-Asn-OEt (1). It is observed that among all the metal ions studied, Ca 2+ ions facilitate the aggregation of the peptide. The interior dielectric constant of the micelles (ε) was found to depend upon the proportion of Ca 2+ complexed peptide with the peptide monomers in the micelles. When Ca 2+ ion becomes 1/4th of the peptide concentration, there is a structural transition leading to drastic change in the interior of the micro dielectric constant (ε m ).

Density and sound velocity measurements and 1H NMR investigations were carried out in aqueous solution at various temperatures for determining the adiabatic compressibility (β) and hydration of the tetrapeptide, TFA. Tyr-Gly-Phe-Ala-Obz I. The present investigation showed changes in the temperature coefficient of adiabatic compressibility at 40 °C. 1H NMR studies indicated the inverse temperature transition in the concentration range studied.