UGC DAE Consortium for Scientific Research

Evolution of structural and vibrational properties of LiScO 2 as observed from the in situ high temperature XRD and Raman spectroscopic studies are presented. Ab initio density functional theory calculations have also been carried out to support them and to derive the electronic properties of LiScO 2 . LiScO 2 exhibits anisotropic expansion with larger expansion along the c- axis (16.5 × 10 −6 K −1 ) compared to a- axis (8.41 × 10 −6 K −1 ). The anisotropy in expansion has been related to the difference in the apical and equatorial Li-O and Sc-O bonds of LiO 6 and ScO 6 octahedra. Overall expansion of unit cell volume is contributed by expansion and distortion of LiO 6 and ScO 6 octahedra. Ab initio phonon calculation revealed 12 Raman active modes but only 8 distinct Raman modes in LiScO 2 . Experimentally, six Raman modes could be identified at ambient and higher temperature, and anharmonic analyses of these modes have carried out. The wavenumbers of all the Raman modes decrease with increasing temperature while a mode at 300 cm −1 is found to be least influenced by temperature. All the modes except that at 300 cm −1 are found to contribute to the expansion of the lattice. Further, equation of states, density of states and band gaps were calculated using density functional theory (DFT). The band gap computed using norm conserving (nc) and LDA or GGA (3.85 or 3.96 eV) agrees well with the band gap (3.96 eV) measured by diffuse reflectance spectroscopy. The calculated bulk modulus (B 0 ) and equilibrium volume (V 0 ) by nc-LDA and nc-GGA are: 119 GPa, 154.8 Å 3 and 104 GPa, 166.3 Å 3 . • Structure, vibrational and electronic properties of LiScO 2 have been reported. • LiScO 2 show high structural stability but strong anisotropic expansions. • Anisotropy in unit cell expansion is related to the distortion and volume of LiO 6 octahedra. • Anharmonic analyses of Raman modes suggest all the modes contribute to the lattice expansion. • LiScO 2 was found to be a direct bandgap semiconductor.

Hepatocellular carcinoma (HCC) continues to be a significant cancer in India, exhibiting a yearly incidence of about 1.6%. The limitations of conventional chemotherapy, such as systemic toxicity and drug resistance, highlight the need of natural chemosensitizers in improving therapeutic outcomes. This study assesses the chemosensitizing ability of Black Grape Anthocyanins (BGA) derived from the Manjari Medika (MM) grape variety to improve the efficacy of low-dose 5-Fluorouracil (5-FU) in HepG2 cells. MM grapes are high in polyphenols and contains 12 different anthocyanin derivatives, as determined by Liquid Chromatography-Mass spectrometry (LC-MS) analysis. HepG2 cells were treated with varying concentrations of 5-FU and BGA, both alone and in combination, and their viability, ROS generation, mitochondrial integrity, calcium influx, apoptosis, and autophagy indicators were measured using biochemical and imaging methods. Co-treatment with 5-FU (50 µM) and BGA (80µg/ml) significantly increased cytotoxicity compared to individual therapies. The combination caused significant cytosolic calcium influx as well as enhanced intracellular and mitochondrial reactive oxygen species (ROS), resulting in mitochondrial depolarisation and structural disintegration. These changes stimulated intrinsic apoptotic signalling, as evidenced by higher Bax and cleaved Caspase-3 expression and lower Bcl-2 levels. Autophagic flux increased concurrently, as demonstrated by overexpression of LC3A/B and Beclin 1 (2.36 and 1.27-fold, respectively). ROS scavenging with NAC reduced these effects, establishing ROS as an important upstream mediator. Importantly, BGA showed little cytotoxicity in primary hepatocytes. Overall, BGA works as a strong, selective chemosensitiser that improves 5-FU efficacy via ROS-mediated regulation of calcium signalling, apoptosis, and autophagy in HCC cells.

Abstract Evolution of structural and dielectric characteristics as a function of thermal annealing temperature (400–600 °C/2h) of MgFe 2 O 4 ferrite nano-powder prepared by sol-gelsynthesis-protocol is reported. Structural characterization is done by X-ray diffraction (XRD), and dielectric response was recorded. XRD confirms presence of nano-crystalline spinel-phase bearing grain diameters in range of 48.01 nm – 64.59 nm. Evolution of structural properties with thermal annealing reveals: i) minor decrease of lattice parameter, ii) Grain growth (from 48.01 – 64.59 nm), iii) weakened A–B, A–A super-exchange and simultaneous increment in the strength of B–B super-exchange interaction, showing decrease of Néel magnetic moment, iv) changes in oxygen parameter and degree of inversion owing to increasing population of Mg 2+ at A site, and that of Fe 3+ ions at B site, v) as frequency increases, real (ε'), imaginary (ε") parts of dielectric-constant, and loss (tan δ) shows declination, vi) AC conductivity (σ ac ) exhibited a power-law dependence and showed a notable increase at higher frequencies. Complex impedance analysis indicates that grain-boundaries significantly influence the dielectric performance at higher frequencies. Enhanced behaviour of σ ac , suggests prospective use of pure MgFe 2 O 4 in RF-based dielectric and electronic device applications.

Tin (Sn) thin films are deposited on BiSe substrate via vapor deposition under ultrahigh vacuum conditions, and the surface electronic structure and interface chemistry are systematically investigated using X‐ray and ultraviolet photoemission spectroscopy (XPS and UPS) measurements. Spectroscopy analysis reveals the formation of SnSe bonds along with a reduction of Bi, leading to the emergence of multiple Sn‐based interfacial phases such as SnSe and SnSe. Thus, our study estabilishes predominance of interfacial chemistry over epitaxial stanene growth on BiSe at room temperature, highlighting the challenges associated with the interface engineering in layered topological systems.