4,072 results match your criteria: "Tata Institute of Fundamental Research; shivaprasad@ncbs.res.in.[Affiliation]"

We determine the arrangement of spins in the ground state of the XY model with quenched, random fields, on a fully connected graph. Two types of disordered fields are considered, namely, randomly oriented magnetic fields and randomly oriented crystal fields. Orientations are chosen from a uniformly isotropic distribution, but disorder fluctuations in each realization of a finite system lead to a breaking of rotational symmetry.

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Nature has ingeniously developed specialized water transporters that effectively reject ions, including protons, while transporting water across membranes. These natural water channels, known as aquaporins (AQPs), have inspired the creation of Artificial Water Channels (AWCs). However, replicating superfast water transport with synthetic molecular structures that exclude salts and protons is a challenging task.

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Polar magneto-optical Kerr effect spectroscopy with a microscope arrangement for studies on 2D materials.

Rev Sci Instrum

August 2024

Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India.

We describe a setup for magneto-optical Kerr effect (MOKE) spectroscopy suitable for Kerr rotation (ϕ) and ellipticity (η) measurement on microscopic samples, such as flakes of two-dimensional materials. A spatial resolution of ∼25μm, limited by the demagnified monochromator exit slit image, was achieved. The use of mirrors allows for measurement in polar MOKE geometry with a conventional electro-magnet, without requiring holes in the magnet pole pieces.

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Deciphering the protein-ligand interactions in a macromolecular complex is crucial for understanding the molecular mechanism, underlying biological processes, and drug development. In recent years, cryogenic sample electron microscopy (cryoEM) has emerged as a powerful technique to determine the structures of macromolecules and to investigate the mode of ligand binding at near-atomic resolution. Identifying and modeling non-protein molecules in cryoEM maps is often challenging due to anisotropic resolution across the molecule of interest and inherent noise in the data.

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Light sheet microscopy has become the methodology of choice for live imaging of zebrafish embryos over long time scales with minimal phototoxicity. In particular, a multiview system, which allows sample rotation, enables imaging of entire embryos from different angles. However, in most imaging sessions with a multiview system, sample mounting is a troublesome process as samples are usually prepared in a polymer tube.

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Crystalline zeolites have high acidity but limited utility due to microporosity, whereas mesoporous amorphous aluminosilicates offer better porosity but lack sufficient acidity. In this work, we investigated defect engineering to fine-tune the acidity of amorphous acidic aluminosilicates (AAS). Here we introduced oxygen vacancies in AAS to synthesize defective acidic aluminosilicates (D-AAS).

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Tailoring solid-state DNP methods to the study of α-synuclein LLPS.

Biophys Chem

October 2024

Center for Quantum and Topological Systems, New York University Abu Dhabi, United Arab Emirates; Department of Chemistry, New York University Abu Dhabi, United Arab Emirates. Electronic address:

Dynamic Nuclear Polarization (DNP) is a technique that leverages the quantum sensing capability of electron spins to enhance the sensitivity of nuclear magnetic resonance (NMR) signals, especially for insensitive samples. Glassing agents play a crucial role in the DNP process by facilitating the transfer of polarization from the unpaired electron spins to the nuclear spins along with cryoprotection of biomolecules. DNPjuice comprising of glycerol-d/DO/HO has been extensively used for this purpose over the past two decades.

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Autophagy-mediated ID1 turnover dictates chemo-resistant fate in ovarian cancer stem cells.

J Exp Clin Cancer Res

August 2024

Imaging Cell Signalling & Therapeutics Lab, Advanced Centre for Treatment, Research and Education in Cancer, Tata Memorial Centre, Navi Mumbai, 410210, India.

Background: The mechanisms enabling dynamic shifts between drug-resistant and drug-sensitive states in cancer cells are still underexplored. This study investigated the role of targeted autophagic protein degradation in regulating ovarian cancer stem cell (CSC) fate decisions and chemo-resistance.

Methods: Autophagy levels were compared between CSC-enriched side population (SP) and non-SP cells (NSP) in multiple ovarian cancer cell lines using immunoblotting, immunofluorescence, and transmission electron microscopy.

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Serial capture affinity purification (SCAP) is a powerful method to isolate a specific protein complex. When combined with cross-linking mass spectrometry and computational approaches, one can build an integrated structural model of the isolated complex. Here, we applied SCAP to dissect a subpopulation of WDR76 in complex with SPIN1, a histone reader that recognizes trimethylated histone H3 lysine4 (H3K4me3).

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A study of the anomalous couplings of the Higgs boson to vector bosons, including -violation effects, has been conducted using its production and decay in the WW channel. This analysis is performed on proton-proton collision data collected with the CMS detector at the CERN LHC during 2016-2018 at a center-of-mass energy of 13 TeV, and corresponds to an integrated luminosity of 138 . The different-flavor dilepton final state is analyzed, with dedicated categories targeting gluon fusion, electroweak vector boson fusion, and associated production with a W or Z boson.

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The negligible cytotoxicity of anion surface-linked dendrons makes glutamic acid-based dendrons a potential candidate for materials and biological applications. Despite the inherent drawbacks of the conventional solution phase synthesis of glutamic acid-based dendrons, there have been no advancements in these protocols. Herein, we demonstrate the first-ever convergent solid phase synthesis of dendrons, up to fourth generation, having glutamic acid branching points produced by preactivation of dicarboxylic acid groups with -hydroxysuccinimide and simultaneous coupling with amine groups of two growing peptide chains, with excellent yields (30-70%).

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Objective: Proteasomes are conserved proteases crucial for proteostasis in eukaryotes and are promising drug targets for protozoan parasites. Yet, the proteasomes of Entamoeba histolytica remain understudied. The study's objective was to analyse the differences in the substrate binding pockets of amoeba proteasomes from those of host, and computational modelling of β5 catalytic subunit, with the goal of finding selective inhibitors.

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Living systems utilize sophisticated biochemical regulators and various signal transduction mechanisms to program bio-molecular assemblies and their associated functions. Creating synthetic assemblies that can replicate the functional and signal-responsive properties of these regulators, while also interfacing with biomolecules, holds significant interest within the realms of supramolecular chemistry and chemical biology. This pursuit not only aids in understanding the fundamental design principles of life but also introduces novel capabilities that contribute to the advancements in medical and therapeutic research.

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Intrinsically disordered protein α-synuclein (αS) is implicated in Parkinson's disease due to its aberrant aggregation propensity. In a bid to identify the traits of its aggregation, here we computationally simulate the multi-chain association process of αS in aqueous as well as under diverse environmental perturbations. In particular, the aggregation of αS in aqueous and varied environmental condition led to marked concentration differences within protein aggregates, resembling liquid-liquid phase separation (LLPS).

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Molecular cavities that mimic natural metalloenzymes have shown the potential to trap elusive reaction intermediates. Here, we demonstrate the formation of a rare yet stable Fe(IV)-superoxo intermediate at room temperature subsequent to dioxygen binding at the Fe(III) site of a (EtN)[Fe(Cl)(bTAML)] complex confined inside the hydrophobic interior of a water-soluble PdL nanocage. Using a combination of electron paramagnetic resonance, Mössbauer, Raman/IR vibrational, X-ray absorption, and emission spectroscopies, we demonstrate that the cage-encapsulated complex has a Fe(IV) oxidation state characterized by a stable S = 1/2 spin state and a short Fe-O bond distance of ∼1.

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The mechanosensory hair cell of the vertebrate inner ear responds to the mechanical deflections that result from hearing or change in the acceleration due to gravity, to allow us to perceive and interpret sounds, maintain balance and spatial orientation. In mammals, ototoxic compounds, disease, and acoustic trauma can result in damage and extrusion of hair cells, without replacement, resulting in hearing loss. In contrast, non-mammalian vertebrates can regenerate sensory hair cells.

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The production of ϒ(2S) and ϒ(3S) mesons in lead-lead (Pb-Pb) and proton-proton (pp) collisions is studied in their dimuon decay channel using the CMS detector at the LHC. The ϒ(3S) meson is observed for the first time in Pb-Pb collisions, with a significance above 5 standard deviations. The ratios of yields measured in Pb-Pb and pp collisions are reported for both the ϒ(2S) and ϒ(3S) mesons, as functions of transverse momentum and Pb-Pb collision centrality.

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We report a novel, reversible, cell-permeable, pH-sensor, TRapH. TRapH afforded a pH-sensitive ratiometric emission response in the pH range ~3-6, enabling imaging and quantification of pH in living cells. The biological-applicability of TRapH was illustrated via live-tracking of intracellular pH dynamics in living mammalian cells induced by a synthetic H-transporter.

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Many bacteria thrive in intricate natural communities, exhibiting key attributes of multicellularity such as communication, cooperation, and competition. The most prevalent manifestation of bacterial multicellular behavior is the formation of biofilms, often linked to pathogenicity. Biofilms offer a haven against antimicrobial agents, fostering the emergence of antimicrobial resistance.

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A search for and production in the final state is presented, where H is the standard model (SM) Higgs boson. The search uses an event sample of proton-proton collisions corresponding to an integrated luminosity of 133 collected at a center-of-mass energy of 13 with the CMS detector at the CERN LHC. The analysis introduces several novel techniques for deriving and validating a multi-dimensional background model based on control samples in data.

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A series of novel sulfonamide and acetamide derivatives of pyrimidine were synthesized and their antimicrobial activities were assessed. Based on the Microbroth dilution method, the minimum inhibitory concentration (MIC) of the synthesized compounds demonstrated moderate to good levels of antifungal and antibacterial activity. Structure-activity relationship analysis suggested that the presence of electron-withdrawing groups, such as halogens, nitrile, and nitro groups, on the pyrimidine ring contributed to the enhanced antimicrobial potency, while electron-donating substituents led to a decrease in activity.

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The honeycomb Kitaev model describes aspin liquid with topological order and fractionalized excitations consisting of gapped-fluxes and free Majorana fermions. Competing interactions, even when not very strong, are known to destabilize the Kitaev spin liquid. Magnetic fields are a convenient parameter for tuning between different phases of the Kitaev systems, and have even been investigated for potentially counteracting the effects of other destabilizing interactions leading to a revival of the topological phase.

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As wounds heal, embryos develop, cancer spreads, or asthma progresses, the cellular monolayer undergoes a glass transition between solid-like jammed and fluid-like flowing states. During some of these processes, the cells undergo an epithelial-to-mesenchymal transition (EMT): they acquire in-plane polarity and become motile. Thus, how motility drives the glassy dynamics in epithelial systems is critical for the EMT process.

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The first search for singly produced narrow resonances decaying to three well-separated hadronic jets is presented. The search uses proton-proton collision data corresponding to an integrated luminosity of 138  fb^{-1} at sqrt[s]=13  TeV, collected at the CERN LHC. No significant deviations from the background predictions are observed between 1.

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