Publications by authors named "Asim K Ghosh"

The current study demonstrates a Cu(I) catalyzed direct C(sp)-H silylation and germylation of azauracil using triphenylsilane and triphenylgermane. A broad scope, excellent functional group tolerance, and suitability for large-scale reactions are exhibited in this protocol. Moreover, this method can be readily applied to structurally complex bioactive molecules.

View Article and Find Full Text PDF

Magnetic and topological properties along with quantum correlations in terms of several entanglement measures have been investigated for an antiferromagnetic (AFM) spin-1/2 XY model in the presence of transverse magnetic field and XZX-YZY type of three-spin interactions. Symmetries of the spin Hamiltonian have been identified. Under the Jordan-Wigner transformation, the spin Hamiltonian converted into spinless superconducting model with nearest neighbor (NN) hopping and Cooper pairing terms in addition to next NN Cooper pairing potential.

View Article and Find Full Text PDF

Introduction: The study aimed to evaluate comparability in terms of efficacy, safety and immunogenicity of Sun's ranibizumab biosimilar with reference ranibizumab in patients with neovascular age-related macular degeneration (nAMD).

Methods: This prospective, randomised, double-blind, two-group, parallel-arm, multicentre, phase 3 comparative study included patients with nAMD ≥ 50 years, randomised (in a 2:1 ratio) in a double-blind manner to receive 0.5 mg (0.

View Article and Find Full Text PDF

Background: Neovascular glaucoma (NVG) is a secondary glaucoma with a poor visual prognosis. Trabeculectomy with antifibrotic agents, glaucoma drainage devices (GDDs), and cyclo-destructive procedures are recommended in patients who are refractory to medical management. However, due to the poor success rate of conventional trabeculectomy and the higher cost of GDDs, alternative procedures need to be looked at.

View Article and Find Full Text PDF

Existence of nontrivial topological phases in a tight binding Haldane-like model on the depleted Lieb lattice is reported. This two-band model is formulated by considering the nearest-neighbor (NN), next-NN (NNN) and next-NNN hopping terms along with complex phase which breaks the time reversal symmetry of this semi-metallic system. Topological feature of this model is studied along with the presence of sublattice symmetry breaking staggered onsite energy.

View Article and Find Full Text PDF

Introduction: Significant surge of mucormycosis was reported in the Indian Subcontinent during the second wave of the COVID-19 pandemic. COVID-associated mucormycosis (CAM) was defined as the development of features of mucormycosis with prior or current history of COVID-19 infection. Rapid angioinvasion is an important characteristic of mucormycosis.

View Article and Find Full Text PDF

Simple route of engineering topological phases for any desired value of winding and Chern numbers is found in the Su-Schrieffer-Heeger (SSH) model by adding a further neighbor hopping term of varying distances. It is known that the standard SSH model yields a single topological phase with winding number, = 1. In this study it is shown that how one can generate topological phases with any values of winding numbers, for examples,ν=±1,±2,±3,…,in the presence of a single further neighbor term which preserves inversion, particle-hole and chiral symmetries.

View Article and Find Full Text PDF

Purpose: In cases of eyelid malignancies requiring full thickness excisional biopsy followed by reconstruction of the created defect, the Meibomian glands are lost. Post-operative varying degrees of dry eye disease (DED) are expected in such patients. The aim was to evaluate the objective and subjective statuses of DED in cases of full thickness eyelid reconstruction following excisional biopsy because of malignancies.

View Article and Find Full Text PDF

Background: Depression has emerged as one of the prime morbidities affecting professional and personal lives worldwide. Antidepressants are one of the mainstays of management of depressive episodes. Although antidepressants are considered a safe class of drugs, the studies examining the effects of antidepressant prescription on intraocular pressure (IOP) have shown a propensity to increase IOP, but not consistently.

View Article and Find Full Text PDF

Purpose: To assess the incidence and cause of idiopathic, irreversible loss of vision ("wipe-out") in the early post-operative period after glaucoma-filtration surgery in advanced glaucoma.

Methods: It was a prospective, interventional cohort study. Patients with advanced glaucoma and macular split fixation underwent either only trabeculectomy (group A) or combined phaco-emulsification with trabeculectomy (group B).

View Article and Find Full Text PDF

Earth-abundant and water-tolerant manganese(i) catalyzed alkenylation of 2-arylindazole with alkyl and aryl alkynes through C-H bond activation is described with a unique level of -selectivity. The reaction proceeds through the control of C3 nucleophilicity of 2-aryl indazoles. This method is applied to the late-stage functionalization of complex molecules including ethinylestradiol, norethisterone, and N-protected amino acid derivatives.

View Article and Find Full Text PDF

The global pandemic due to the outbreak of COVID-19 ravages the whole world for more than two years in which all the countries are suffering a lot since December 2019. In this article characteristics of a multi-wave SIR model have been studied which successfully explains the features of this pandemic waves in India. Origin of the multi-wave pattern in the solution of this model is explained.

View Article and Find Full Text PDF

Aim: To share clinical pattern of presentation, the modalities of surgical intervention and the one month post-surgical outcome of rhino-orbito-mucormycosis (ROCM) cases.

Methods: All COVID associated mucormycosis (CAM) patients underwent comprehensive multidisciplinary examination by ophthalmologist, otorhinolaryngologist and physician. Patients with clinical and radiological evidence of orbital apex involvement were included in the study.

View Article and Find Full Text PDF

Root nodule symbiosis (RNS) is the pillar behind sustainable agriculture and plays a pivotal role in the environmental nitrogen cycle. Most of the genetic, molecular, and cell-biological knowledge on RNS comes from model legumes that exhibit a root-hair mode of bacterial infection, in contrast to the Dalbergoid legumes exhibiting crack-entry of rhizobia. As a step toward understanding this important group of legumes, we have combined microscopic analysis and temporal transcriptome to obtain a dynamic view of plant gene expression during (peanut) nodule development.

View Article and Find Full Text PDF

Rhodium-catalyzed directed C-H functionalization of 2-arylindazoles with -sulfonylformaldimines has been developed to provide a variety of -benzylarylsulfonamide derivatives with good to excellent yields. Different activated aldehydes like ethyl glyoxalate and 2,2,2-trifluoroacetaldehyde also efficiently underwent nucleophilic addition with 2-arylindazoles. These selective transformations occur through the control of C3 nucleophilicity of indazole moiety.

View Article and Find Full Text PDF

An efficient and practical method has been developed for the synthesis of steroidal imidazoheterocycles via cost-effective and environmentally benign FeCl-catalyzed oxidative amination. A library of steroidal imidazo[1,2-a]pyridines was directly synthesized from readily available 2-aminopyridines and steroidal ketones in aerobic conditions. The synthesized compounds were screened for activity on human microsomal cytochrome P450s CYP7, CYP17 and CYP21.

View Article and Find Full Text PDF

A general and practical method for the direct C-H amination of 2-indazoles with a series of amines including aliphatic primary amines, secondary amines, azoles, and sulfoximines via organophotoredox-catalyzed oxidative coupling has been disclosed at room temperature under ambient air conditions. Additionally, this protocol is used for free aminated 2-indazole synthesis. A mechanistic study revealed that a single electron transfer (SET) pathway might be involved in this reaction.

View Article and Find Full Text PDF

Switchable Rh(iii)-catalyzed highly regioselective hydroarylation and oxidative arylation of maleimides with 2-arylindazoles via C-H activation have been demonstrated. The reaction affords 3-(2-(2H-indazol-2-yl)phenyl)succinimide and 3-(2-(2H-indazol-2-yl)phenyl)maleimide derivatives in high yields with wide functional group tolerance. A mechanistic study was performed to depict C-H bond cleavage that might be involved in the turnover limiting step.

View Article and Find Full Text PDF

A number of topological nodes including Dirac, quadratic and three-band touching points as well as a pair of degenerate Dirac line nodes are found to emerge in the triplet plaquette excitations of the frustrated spin-1/2-antiferromagnetic Heisenberg honeycomb model when the ground state of the system lies in a spin-disordered plaquette-valence-bond-solid phase. A six-spin plaquette operator theory of this honeycomb model has been developed for this purpose by using the eigenstates of an isolated Heisenberg hexagonal plaquette. Spin-1/2 operators are thus expressed in the Fock space spanned by the plaquette operators those are obtained in terms of exact analytic form of eigenstates for a single frustrated Heisenberg hexagon.

View Article and Find Full Text PDF

A simple and highly efficient method for the oxo-sulfonylation of aldehyde-derived hydrazones has been developed using sulfinic acid as a source of sulfonyl group and oxygen as a green oxidant under metal-free conditions at room temperature. The present C-O and N-S bond-forming difunctionalization strategy affords diversely functionalized -acylsulfonamides in good yield. Experimental results suggest a radical mechanistic pathway of the present reaction.

View Article and Find Full Text PDF

We study the transport properties of Dirac electrons across a two-dimensional normal metal-barrier-normal metal interface in monolayer borophane. We analyse the transmission probability with variation of the width of the barrier region, the incidence energy and transverse momentum. We demonstrate that a gap exists in the transmission probability spectrum and the position of the width of the transmission gap can be tuned by the barrier strength and transverse momentum respectively.

View Article and Find Full Text PDF

In this work, topological properties of a ferromagnetic Heisenberg model on a breathing kagome lattice are investigated extensively in the presence of Dzyaloshinskii-Moriya interaction. While the kagome ferromagnet hosts only a single first order topological phase, the breathing kagome system exhibits multiple first and second order topological phases along with their coexistence. Magnon dispersion relation is obtained by using linear spin wave theory.

View Article and Find Full Text PDF

Polycystic ovarian syndrome (PCOS) is one of the most common endocrine disorders in women of both developed and developing countries. It is associated with insulin resistance, hyperinsulinemia, hyperandrogenism, oxidative stress and various long-term complications. The present study was undertaken to evaluate the efficacy and safety of the supplementation (Trazer F Forte-CORONA Remedies Pvt.

View Article and Find Full Text PDF

In this study, a tight-binding model on square-octagon lattice with nearest-neighbour and next-nearest-neighbour hoppings is considered. The system is topologically trivial although it exhibits quadratic band-touching points in its band-structure. It is shown that the system drives towards topologically non-trivial phases as soon as it is exposed to monochromatic circularly polarized light.

View Article and Find Full Text PDF