Shiv Nadar University

About: Shiv Nadar University is a education organization based out in Dadri, Uttar Pradesh, India. It is known for research contribution in the topics: Population & Graphene. The organization has 1015 authors who have published 1924 publications receiving 18420 citations.

Black hole in a superconducting plasma

Abstract: The generalized vortical formalism provides an electrodynamic description for superconducting states---in the generalized vortical formalism, a superconducting state may be defined by the vanishing of an appropriate generalized vorticity and characterized by zero generalized helicity for incompressible fluids. In this article, we investigate these states for incompressible plasmas in black hole spacetime geometries using the curved spacetime generalization of the grand generalized vortical formalism. If the magnetic field is axisymmetric and the thermodynamic properties are symmetric about the equatorial plane, the resulting states are characterized by a vanishing skin depth and a complete expulsion of the magnetic field at the equator of the black hole horizon. Moreover, if the thermodynamic properties of the plasma are uniform at the horizon, we find that the magnetic field is completely expelled from the horizon, and the plasma behaves as a perfect superconductor near the horizon. This result is independent of the spin of a black hole, holding even for a (nonrotating) Schwarzschild black hole, and demonstrates that the geometry near black hole horizons can have a significant effect on the electrodynamics of surrounding plasmas.

An Efficient Molecular Luminophore based on Tetraphenylethylene (TPE) Enabling intracellular Detection and Therapeutic Benefits of Hydrogen Sulfide in Alzheimer’s Disease

Abstract: Hydrogen sulfide (H2S), an essential neurotransmitter, regulates physiological processes, including brain function. Lower level of endogenously produced H2S may lead to Alzheimer’s disease (AD), which is a progressive neurodegenerative disorder characterized by the deposition and aggregation of amyloid-beta (Aβ) peptides in the brain tissue. Developing a molecular probe enabling sensing and visualizing of Aβ-disaggregates caused by H2S would be a potential therapeutic benefit for Alzheimer’s disease. Herein, we report a rational design and synthesis of an orthogonally substituted tetraphenylethylene (TPE) dual functional turn-on molecular luminophore TPE-NBD-D. The current strategy centers on a TPE-core appended with an ancillary H2S sensing unit i.e., 4-chloro-7-nitrobenzofurazan (NBD) and a disulfide linked donor (D: 4-(pyridin-2-yldisulfaneyl)-benzoate) as a source of H2S in presence of bio-thiols. The disulfide-linked H2S-donor is cleaved off from the TPE by esterase and its counterpart exhibited a turn-on fluorescence response after releasing NBD ligand in bio-thiol environments. Molecular probe TPE-NBD-D, showed a marked efficiency to detect H2S in solution state (LOD 0.1 µM) through AIE phenomenon and featured its aqueous solubility, cell membrane permeability, low cytotoxicity and high selectivity towards H2S. The probe enabled to detect intracellular H2S in neuroblastoma cell line SHSY-5Y as reflected by the turn-on fluorescence. Further, the TPE-NBD-D has been employed in vivo mice model where the probe is capable of releasing H2S in thiol abundant colorectal area and opens up a new insight to understand the involvement of H2S releasing molecules in the management of Alzheimer’s disease (AD). Eventually, the H2S production by TPE-NBD-D has been demonstrated to induce the Aβ1-42 de-agglomeration which is meticulously monitored by the AFM, SEM and Raman fingerprint analysis of the model agglomerated form of Aβ1-42 protein. This is the first time, we revealed TPE-structured molecular probe enabling as H2S donor and utilized for amyloid beta de-agglomeration without imparting any cytotoxicity. Therefore, this probe may be a potential chemical tool for the diagnosis and treatment of AD.

Unveiling Temperature-Mediated Dual-Band Edge in TiO2 Nanotubes with Enhanced Photocatalytic Effect

Abstract: An annealing temperature-driven appearance of a sharp dual-band edge in the ultraviolet–visible absorption spectrum of electrochemically anodized TiO2 nanotubes (TNTs) and the corresponding impact ...

Development of large volume double ring penning plasma discharge source for efficient light emissions

Abstract: In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd2Fe14B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ∼0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique ...

A pedestrian introduction to coherent and squeezed states

Abstract: This review is intended for readers who want to have a quick understanding on the theoretical underpinnings of coherent states and squeezed states which are conventionally generated from the protot...