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.

Characterization of highly conserved G-quadruplex motifs as potential drug targets in Streptococcus pneumoniae

Abstract: Several G-quadruplex forming motifs have been reported to be highly conserved in the regulatory regions of the genome of different organisms and influence various biological processes like DNA replication, recombination and gene expression. Here, we report the highly conserved and three potentially G-quadruplex forming motifs (SP-PGQs) in the essential genes (hsdS, recD, and pmrA) of the Streptococcus pneumoniae genome. These genes were previously observed to play a vital role in providing the virulence to the bacteria, by participating in the host-pathogen interaction, drug-efflux system and recombination- repair system. However, the presence and importance of highly conserved G-quadruplex motifs in these genes have not been previously recognized. We employed the CD spectroscopy, NMR spectroscopy, and electrophoretic mobility shift assay to confirm the adaptation of the G-quadruplex structure by the SP-PGQs. Further, ITC and CD melting analysis revealed the energetically favorable and thermodynamically stable interaction between a candidate G4 binding small molecule TMPyP4 and SP-PGQs. Next, TFP reporter based assay confirmed the regulatory role of SP-PGQs in the expression of PGQ harboring genes. All these experiments together characterized the SP-PGQs as a promising drug target site for combating the Streptococcus pneumoniae infection.

Fingerprint liveness detection using local quality features

Abstract: Fingerprint-based recognition is widely deployed in different domains. However, current recognition systems are vulnerable to presentation attack. Presentation attack utilizes an artificial replica of a fingerprint to deceive the sensors. In such scenarios, fingerprint liveness detection is required to ensure the actual presence of a live fingerprint. In this paper, we propose a static software-based approach using quality features to detect the liveness in a fingerprint image. The proposed method extracts eight sensor-independent quality features from the detailed ridge–valley structure of a fingerprint at the local level to form a 13-dimensional feature vector. Sequential Forward Floating Selection and Random Forest Feature Selection are used to select the optimal feature set from the created feature vector. To classify fake and live fingerprints, we have used support vector machine, random forest, and gradient boosted tree classifiers. The proposed method is tested on a publically available database of LivDet 2009 competition. The experimental results demonstrate that the least average classification error of 5.3% is achieved on LivDet 2009 database, exhibiting supremacy of the proposed method over current state-of-the-art approaches. Additionally, we have analyzed the importance of individual features on LivDet 2009 database, and effectiveness of the best-performing features is evaluated on LivDet 2011, 2013, and 2015 databases. The obtained results depict that the proposed approach is able to perform well irrespective of the different sensors and materials used in these databases. Further, the proposed method utilizes a single fingerprint image. This characteristic makes our method more user-friendly, faster, and less intrusive.

Organometallic halogen bond acceptors: directionality, hybrid cocrystal precipitation, and blueshifted CO ligand vibrational band

Abstract: Iron cyclopentadienyl carbonyl-halide and -chalcogenolate complexes CpFe(CO)2X (X = Cl, Br, I, TePh, SPh) readily afford cocrystals with the bidentate halogen bond donor 1,4-diiodotetrafluorobenzene (p-DITFB) under slow evaporation or vapor diffusion conditions. The same microcrystalline [CpFe(CO)2TePh](p-DITFB) product instantly precipitates upon mixing p-DITFB and CpFe(CO)2TePh in hexane solution. Supramolecular [CpFe(CO)2X(p-DITFB)]n chains in the cocrystals are assembled by halogen bonds (XB) between the electrophilic area of iodine atoms of p-DITFB and the nucleophilic area of X in CpFe(CO)nX. The 5–10 cm−1 hypsochromic shift of the CO stretching bands in the IR spectra of [CpFe(CO)2X(p-DITFB)] cocrystals is explained by the pronounced electron-withdrawing effect of halogen bonding (XB), as supported by DFT calculations. The observed influence of the nature of the XB acceptor (X) on the XB geometry is described in terms of hybridization and electrostatic surface potential (ESP) mapping.

Recent Progress and Challenges in A3Sb2X9-Based Perovskite Solar Cells.

Abstract: The recent trends and current state of perovskite solar cells (PSCs) suggested their potential for practical applications. Since their origin, organic-inorganic lead halide (MAPbX3) perovskite material-based PSCs have been widely attractive to the scientific community due to their simple manufacturing process, high performance, and cost effectiveness. In spite of the high performance, the lead halide perovskite solar cells are still agonizing due to the long-term stability and toxic nature of Pb. In the last 4 years or so, many alternative perovskite or perovskite-like materials were explored for the development of Pb-free PSCs. However, antimony (Sb)-based perovskite-like materials have shown enhanced stability and average photovoltaic performance. In this mini-review, we discuss the fabrication, recent trends, and current state of the Sb-based PSCs.