Indian Institute of Technology Indore

About: Indian Institute of Technology Indore is a education organization based out in Indore, Madhya Pradesh, India. It is known for research contribution in the topics: Computer science & Chemistry. The organization has 1606 authors who have published 4803 publications receiving 66500 citations.

Insights into the Thermodynamics of Polymer Nanodot–Human Serum Albumin Association: A Spectroscopic and Calorimetric Approach

Abstract: With the advent of newer luminescent nanoparticles for bioimaging applications, their complex interactions with individual biomolecules need to be understood in great detail, before their direct application into cellular environments. Here, we have presented a systematic and detailed study on the interaction between luminescent polymer nanodots (PNDs) and human serum albumin (HSA) in its free and ligand-bound state with the help of spectrophotometric and calorimetric techniques. At physiological pH (pH = 7.4), PNDs quench the intrinsic fluorescence of HSA as a consequence of ground-state complex formation. The binding stoichiometry and various thermodynamic parameters have been evaluated by using isothermal titration calorimetry and the van’t Hoff equation. It has been found that the association of PNDs with HSA is spontaneous (ΔG0 = −32.48 ± 1.24 kJ mol–1) and is driven by a favorable negative standard enthalpy change (ΔH0 = −52.86 ± 2.12 kJ mol–1) and an unfavorable negative standard entropy change (ΔS0...

$BitCoding$: Network Traffic Classification Through Encoded Bit Level Signatures

Abstract: With many network protocols using obfuscation techniques to hide their identity, robust methods of traffic classification are required. In traditional deep-packet-inspection (DPI) methods, application specific signatures are generated with byte-level data from payload. Increasingly new data formats are being used to encode the application protocols with bit-level information which render the byte-level signatures ineffective. In this paper, we describe BitCoding a bit-level DPI-based signature generation technique. BitCoding uses only a small number of initial bits from a flow and identify invariant bits as signature. Subsequently, these bit signatures are encoded and transformed into a newly defined state transition machine transition constrained counting automata. While short signatures are efficient for processing, this will increase the chances of collision and cross signature matching with increase in number of signatures (applications). We describe a method for signature similarity detection using a variant of Hamming distance and propose to increase the length of signatures for a subset of protocols to avoid overlaps. We perform extensive experiments with three different data sets consisting of 537 380 flows with a packet count of 3 445 969 and show that, BitCoding has very good detection performance across different types of protocols (text, binary, and proprietary) making it protocol-type agnostic. Further, to understand the portability of signatures generated we perform cross evaluation, i.e., signatures generated from one site are used for testing with data from other sites to conclude that it will lead to a small compromise in detection performance.

Polypharmacology or Promiscuity? Structural Interactions of Resveratrol With Its Bandwagon of Targets.

Abstract: Resveratrol (3, 4', 5-trihydroxy-trans-stilbene) is a natural phytoalexin found in grapes and has long been thought to be the answer to the "French Paradox." There is no shortage of preclinical and clinical studies investigating the broad therapeutic activity of resveratrol. However, in spite of many comprehensive reviews published on the bioactivity of resveratrol, there has yet to be a report focused on the variety and complexity of its structural binding properties, and its multi-targeted role. An improved understanding of disease mechanisms at the systems level has enabled targeted polypharmacology to mature into a rational drug discovery approach. Unlike traditional hit-to-lead campaigns that typically optimize activity and selectivity for a single target, polypharmacological drugs aim to selectively target multiple proteins, while avoiding critical off target interactions. This strategy bears promise of improved efficacy and reduced clinical attrition. This review seeks to investigate whether the bioactivity of resveratrol is due to a polypharmacological effect or promiscuity of the phenolic small molecule by examining the modes of binding with its diverse collection of protein targets. We focused on annotated targets, identified via the ChEMBL database, and matched these targets to a representative structure deposited in the Protein Data Bank (PDB), as crystal structures are most informative in understanding modes of binding at the atomic level. We discuss the structural aspects of resveratrol itself that permits binding to multiple proteins in various signaling pathways. Furthermore, we suggest that resveratrol's bioactivity is a result of scaffold promiscuity rather than polypharmacology, and the variety of binding modes across targets display little similarity in the pattern of target interaction.

Disappearance of dielectric anomaly in spite of presence of structural phase transition in reduced BaTiO3: Effect of defect states within the bandgap

Abstract: We report the structural, optical, ferroelectric, and dielectric properties of reduced BaTiO3 samples. For this purpose, oxygen vacancies in BaTiO3 are created by heating these samples with a Ti metal in a vacuum environment at different temperatures. It is observed that with an increase in oxygen deficiencies, the c/a ratio decreases as compared to that of the oxygen treated sample. The ferroelectric properties of the oxygen deficient samples are visibly different as compared to those of the oxygen treated sample. The disappearance of the P-E loop and the anomaly in the temperature variation of the dielectric constant have been observed; however, the structural phase transition corresponding to ferroelectric phase transitions still persists. Thus, it appears that the anomaly in dielectric data and the presence of the P-E loop are getting masked possibly by the Maxwell-Wagner effect. The presence of Ti+3 states in the prepared samples has been confirmed by X-ray absorption near edge structure measurements. The Kubelka-Munk optical absorption shows the presence of extra states below fundamental transition, indicating the emergence of new electronic states within the bandgap, which might be due to Ti+3 states. These new states appear at different energy positions, and with different intensities for different samples, which are reduced in the presence of Ti. These new states within the bandgap appear to modify the electronic structure, thereby reducing the overall bandgap, and hence, they seem to modify the ferroelectric and dielectric properties of the samples. Our results may be treated as experimental evidence for theoretically proposed defect states in oxygen deficient or reduced BaTiO3.

Determination of the optical gap bowing parameter for ternary Ni1-xZnxO cubic rocksalt solid solutions.

Abstract: The lattice parameter variation for phase pure cubic rocksalt (RS) Ni1−xZnxO ternary solid solutions is observed to be perfectly governed by Vegard's law. X-ray absorption near edge spectroscopy confirms the RS symmetry of Zn atoms in the cubic lattice of Ni1−xZnxO. The optical gap bowing parameter for RS Ni1−xZnxO ternary solid solutions is determined, using diffuse reflectivity, to be −0.93 ± 0.05 eV. The negative value of the bowing indicates a repulsive interaction between the ligand O-2p and the metal Ni-3d orbitals. The determined value of the bowing parameter can be useful in designing UV photodetectors based on Ni1−xZnxO solid solutions.