PHYTOCHEMICAL TO INTERACT WITH NLS BINDING SITE ON IMA3 TO INHIBIT IMPORTIN Α/Β1 MEDIATED NUCLEAR IMPORT OF SARS-COV-2 CARGO

Objective: Ivermectin is an FDA-approved, broad-spectrum anti-parasitic agent. It was originally identified as an inhibitor of interaction between the human 29 immunodeficiency virus-1 (HIV-1) integrase protein (IN) and the Importin (IMP) α/β1 30 heterodimers, which are responsible for IN nuclear import. Recent studies demonstrate that ivermectin is worthy of further consideration as a possible SARS-CoV-2 antiviral. Methods: We built the pathogen-host interactome and analyzed it using PHISTO. We compared Ivermectin and plant molecules for their interaction with Importin α3 (IMA3) using molecular docking studies. Results: A phytochemical ATRI001 with the lowest binding energy-7.290 Kcal/mol was found to be superior to Ivermectin with binding energy-4.946 Kcal/mol. Conclusion: ATRI001 may be a potential anti-SARS-CoV-2 agent; however, it requires clinical evaluation

Persistent supersolid phase of hard-core bosons on the triangular lattice

We study hard-core bosons with unfrustrated hopping ($t$) and nearest neighbour repulsion ($U$) on the triangular lattice. At half-filling, the system undergoes a zero temperature ($T$) quantum phase transition from a superfluid phase at small $U$ to a supersolid at $U_c \approx 4.45$ in units of $2t$. This supersolid phase breaks the lattice translation symmetry in a characteristic $\sqrt{3} \times \sqrt{3}$ pattern, and is remarkably stable--indeed, a smooth extrapolation of our results indicates that the supersolid phase persists for arbitrarily large $U/t$.Comment: 4 pages, 5 figures, two column forma

60Co γ-ray induced gain degradation in bipolar junction transistors

Commercial indigenously made npn and pnp bipolar junction switching transistors used for space applications are investigated for 60Co γ-ray induced effects. The on-line as well as off-line measurements indicate that the forward current gain of the transistors decreases significantly as the accumulated dose increases. Excess base current model is employed to account for the current gain degradation. The pnp transistor undergoes as much degradation as the npn type. It is found that bulk degradation by displacement damage is the dominant mechanism leading to reduction in forward current gain of npn transistors. On the other hand it appears that, in addition to bulk damage, surface degradation due to accumulation of interface states at the silicon-silicon dioxide interface also contributes significantly to gain degradation in pnp transistor as evident from thermal annealing studies. Further, estimation reveals that the transistor with larger base width has higher displacement damage factor

Random Coulomb antiferromagnets: from diluted spin liquids to Euclidean random matrices

We study a disordered classical Heisenberg magnet with uniformly antiferromagnetic interactions which are frustrated on account of their long-range Coulomb form, {\em i.e.} $J(r)\sim -A\ln r$ in $d=2$ and $J(r)\sim A/r$ in $d=3$. This arises naturally as the $T\rightarrow 0$ limit of the emergent interactions between vacancy-induced degrees of freedom in a class of diluted Coulomb spin liquids (including the classical Heisenberg antiferromagnets on checkerboard, SCGO and pyrochlore lattices) and presents a novel variant of a disordered long-range spin Hamiltonian. Using detailed analytical and numerical studies we establish that this model exhibits a very broad paramagnetic regime that extends to very large values of $A$ in both $d=2$ and $d=3$. In $d=2$, using the lattice-Green function based finite-size regularization of the Coulomb potential (which corresponds naturally to the underlying low-temperature limit of the emergent interactions between orphan-spins), we only find evidence that freezing into a glassy state occurs in the limit of strong coupling, $A=\infty$, while no such transition seems to exist at all in $d=3$. We also demonstrate the presence and importance of screening for such a magnet. We analyse the spectrum of the Euclidean random matrices describing a Gaussian version of this problem, and identify a corresponding quantum mechanical scattering problem.Comment: two-column PRB format; 17 pages; 24 .eps figure

Semiclassical spin liquid state of easy axis Kagome antiferromagnets

Motivated by recent experiments on Nd-langasite, we consider the effect of strong easy axis single-ion anisotropy $D$ on $S > 3/2$ spins interacting with antiferromagnetic exchange $J$ on the Kagome lattice. When $T \ll DS^2$, the collinear low energy states selected by the anisotropy map on to configurations of the classical Kagome lattice Ising antiferromagnet. However, the low temperature limit is quite different from the cooperative Ising paramagnet that obtains classically for $T \ll JS^2$. We find that sub-leading ${\mathcal O}(J^3S/D^2)$ multi-spin interactions arising from the transverse quantum dynamics result in a crossover from an intermediate temperature classical cooperative Ising paramagnet to a semiclassical spin liquid with distinct short-ranged correlations for $T \ll J^3S/D^2$.Comment: 4 pages, 3 eps figure

Long term Ultra-Violet Variability of Seyfert galaxies

Flux variability is one of the defining characteristics of Seyfert galaxies, a class of active galactic nuclei (AGN). Though these variations are observed over a wide range of wavelengths, results on their flux variability characteristics in the ultra-violet (UV) band are very limited. We present here the long term UV flux variability characteristics of a sample of fourteen Seyfert galaxies using data from the International Ultraviolet Explorer acquired between 1978 and 1995. We found that all the sources showed flux variations with no statistically significant difference in the amplitude of UV flux variation between shorter and longer wavelengths. Also, the flux variations between different near-UV (NUV, 1850 - 3300 A) and far-UV (FUV, 1150 - 2000 A) passbands in the rest frames of the objects are correlated with no time lag. The data show indications of (i) a mild negative correlation of UV variability with bolometric luminosity and (ii) weak positive correlation between UV variability and black hole mass. At FUV, about 50% of the sources show a strong correlation between spectral indices and flux variations with a hardening when brightening behaviour, while for the remaining sources the correlation is moderate. In NUV, the sources do show a harder when brighter trend, however, the correlation is either weak or moderate.Comment: Accepted by Journal of Astrophysics and Astronom

Salinity tolerance and fishery of mud shrimp Solenocera crassicornis (H. Milne Edwards) in the coastal waters of Mumbai

Salinity tolerance of mud shrimp Solenocera crassicornis investigated at different salinities ranging from 15‰ to 55‰ showed that shrimps in the salinity range 30‰ - 42‰ survived but those in lower and higher salinities died soon after the transfer. Ionic concentration in the hemolymph and free amino acids in the body muscle in response to different salinity ranges showed hypo-regulation initially but later became hyposmotic to the medium and died eventually when the salinity decreased. The abundance of shrimp showed inverse relationship with rainfall and consequent lowering of salinity in the inshore waters. The study showed that S. crassicornis can regulate osmotic and ionic concentrations of body fluids efficiently in the salinity range of 30 - 42‰ but unlike euryhaline penaeid shrimps it is a poor regulator at lower salinities and therefore it migrates offshore during monsoon months

The effect of composition, electron irradiation and quenching on ionic conductivity in a new solid polymer electrolyte: (PEG) x NH4I

We have prepared, characterized and investigated a new PEG-2000 based solid polymer electrolyte (PEG) x NH4I. Ionic conductivity measurements have been made as a function of salt concentration as well as temperature in the range 265–330 K. Selected compositions of the electrolyte were exposed to a beam of 8 MeV electrons to an accumulated dose of 10 kGy to study the effect on ionic conductivity. The electrolyte samples were also quenched at liquid nitrogen temperature and conductivity measurements were made. The ionic conductivity at room temperature exhibits a characteristic double peak for the composition x = 20 and 70. Both electron beam irradiation and quenching at low temperature have resulted in an increase in conductivity by 1–2 orders of magnitude. The enhancement of conductivity upon irradiation and quenching is interpreted as due to an increase in amorphous region and decrease in crystallinity of the electrolyte. DSC and proton NMR measurements also support this conclusion

Study of molecular dynamics and cross relaxation in tetramethylammonium hexafluorophosphate (CH3)4NPF6 by 1H and 19F NMR

(CH3)4NPF6 is studied by NMR measurements to understand the internal motions and cross relaxation mechanism between the heterogeneous nuclei. The spin lattice relaxation times (T1) are measured for 1H and 19F nuclei, at three (11.4, 16.1 and 21.34 MHz) Larmor frequencies in the temperature range 350-50 K and 1H NMR second moment measurements at 7 MHz in the temperature range 300-100 K employing home made pulsed and wide-line NMR spectrometers. 1H NMR results are attributed to the simultaneous reorientations of both methyl and tetramethylammonium groups and motional parameters are evaluated. 19F NMR results are attributed to cross relaxation between proton and fluorine and motional parameters for the PF6 group reorientation are evaluated. © 2008 Elsevier Inc. All rights reserved