Publications by authors named "Partha Dey"

An established concept to create radical intermediates is photoexcitation of a catalyst to a higher energy intermediate, subsequently leading to a photoinduced electron transfer (PET) with a reaction partner. The known concept of consecutive photoinduced electron transfer (con-PET) leads to catalytically active species even higher in energy by the uptake of two photons. Generally speaking, increased photon uptake leads to a more potent reductant.

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In eukaryotic cells, DNA is wrapped around histone octamers to compact the genome. Although such compaction is required for the precise segregation of the genome during cell division, it restricts the DNA-protein interactions essential for several cellular processes. During meiosis, a specialized cell division process that produces gametes, several DNA-protein interactions are crucial for assembling meiosis-specific chromosome structures, meiotic recombination, chromosome segregation, and transcriptional regulation.

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Genome-wide association studies have uncovered mostly non-coding variants at over 60 genetic loci linked to susceptibility for age-related macular degeneration (AMD). To ascertain the causal gene at the PILRB/PILRA locus, we used a CRISPR strategy to produce germline deletions in the mouse paired immunoglobin-like type 2 receptor (Pilr) genes that encode highly related activating (PILRB) and inhibitory (PILRA) receptors. We show that a combined loss of Pilrb1 and Pilrb2, but not Pilra, leads to an early but relatively stationary defect as the electroretinography (ERG) amplitudes of Pilrb1/2-/- mice exhibit a marked reduction as early as postnatal day 15 and do not show additional significant decrease at 3 and 12-months.

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Notch-Delta-Jagged (NDJ) signaling among neighboring cells contributes crucially to spatiotemporal pattern formation and developmental decision-making. Despite numerous detailed mathematical models, their high-dimensionality parametric space limits analytical treatment, especially regarding local microenvironmental fluctuations. Using the low-dimensional dynamics of the recently postulated least microenvironmental uncertainty principle (LEUP) framework, we showcase how the LEUP formalism recapitulates a noisy NDJ spatial patterning.

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Single-Molecule Tracking (SMT) is a powerful method to quantify protein dynamics in live cells. Recently, we have established a data analysis pipeline for estimating various biophysical parameters (mean squared displacement, diffusion coefficient, bound fraction, residence time, jump distances, jump angles, and track statistics) from the single-molecule time-lapse movies acquired from yeast . We acquired the time-lapse movies using different time intervals (i.

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Single-molecule tracking (SMT) is a powerful approach to quantify the biophysical parameters of protein dynamics in live cells. Here, we describe a protocol for SMT in live cells of the budding yeast Saccharomyces cerevisiae. We detail how to genetically engineer yeast strains for SMT, how to set up image acquisition parameters, and how different software programs can be used to quantify a variety of biophysical parameters such as diffusion coefficient, residence time, bound fraction, jump angles, and target-search parameters.

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De novo protein synthesis is required for synapse modifications underlying stable memory encoding. Yet neurons are highly compartmentalized cells and how protein synthesis can be regulated at the synapse level is unknown. Here, we characterize neuronal signaling complexes formed by the postsynaptic scaffold GIT1, the mechanistic target of rapamycin (mTOR) kinase, and Raptor that couple synaptic stimuli to mTOR-dependent protein synthesis; and identify NMDA receptors containing GluN3A subunits as key negative regulators of GIT1 binding to mTOR.

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Single-molecule imaging has gained momentum to quantify the dynamics of biomolecules in live cells, as it provides direct real-time measurements of various cellular activities under their physiological environment. Yeast, a simple and widely used eukaryote, serves as a good model system to quantify single-molecule dynamics of various cellular processes because of its low genomic and cellular complexities, as well as its facile ability to be genetically manipulated. In the past decade, significant developments have been made regarding the intracellular labeling of biomolecules (proteins, mRNA, fatty acids), the microscopy setups to visualize single-molecules and capture their fast dynamics, and the data analysis pipelines to interpret such dynamics.

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Objective of our study was to determine the clinical characteristics and laboratory profile of scrub typhus patients requiring pediatric intensive care admission and to find out risk factors for the severity of illness. This was a cross-sectional observational study conducted on 1-month to 12-year-old children admitted with scrub typhus in a tertiary care pediatric intensive care unit (PICU). Relevant demographic, clinical, laboratory, treatment, and outcome-related data were documented.

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A family of eleven glycosylphosphatidylinositol-anchored aspartyl proteases, commonly referred to as CgYapsins, regulate a myriad of cellular processes in the pathogenic yeast Candida glabrata, but their protein targets are largely unknown. Here, using the immunoprecipitation-mass spectrometry approach, we identify the flavodoxin-like protein (Fld-LP), CgPst2, to be an interactor of one of the aspartyl protease CgYps1. We also report the presence of four Fld-LPs in C.

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Boron carbide powder was hot-pressed at 2070 °C with 30 MPa uniaxial pressure and 90 min soaking. The mechanical, microstructure and other related properties were evaluated. XRD of the boron carbide powder and sintered samples, shows the presence of BC phase of high electrical conductivity.

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Probucol, a hypocholesterolemic compound, is neuroprotective in several models of neurodegenerative diseases but has serious adverse effects in vivo. We now describe the design and synthesis of two new probucol analogues that protect against glutamate-induced oxidative cell death, also known as ferroptosis, in cultured mouse hippocampal (HT22) cells and in primary cortical neurons, while probucol did not show any protective effect. Treatment with both compounds did not affect glutathione depletion but still significantly decreased glutamate-induced production of oxidants, mitochondrial superoxide generation, and mitochondrial hyperpolarization in HT22 cells.

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Growth dynamics of thin films expressed by scaling theory is a useful tool to quantify the statistical properties of the surface morphology of the thin films. To date, the growth mechanism for 2D van der Waals materials has been rarely investigated. In this work, an experimental investigation was carried out to identify the scaling behavior as well as the growth mechanism of 2D MoS thin films, grown on glass substrates by pulsed laser deposition for different deposition time durations, using atomic force microscopy images.

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The surface scaling behavior of nanostructured Cu thin films, grown on glass substrates by the pulsed laser deposition technique, as a function of the deposition time has been studied using height-height correlation function analysis from atomic force microscopy (AFM) images. The scaling exponents , , / and of the films were determined from AFM images. The local roughness exponent, , was found to be ∼0.

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The soil of Slovak Republic is severely contaminated with heavy metals, creating hazards to soil health. In order to assess the current status with the prospect of selecting the appropriate treatment methods and land use, this investigation aimed to determine a panel of complementary and ecologically relevant biomarkers that reflect adverse biological responses towards terrestrial pollutants. To attain this objective, the concentration of reduced glutathione and enzymes of glutathione antioxidant system were assessed in clitellate earthworm, Aporrectodea caliginosa sampled from selected sites of eastern Slovakia along with the pH and total metal concentration (As, Cd, Pb, Cr, Hg, Mn, Fe, Co, Ni, Cu, Zn) of soils.

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In the present report, the structural, compositional, morphological, and photoluminescence properties of nanostructured non-stoichiometric silicon oxide (nc-Si:SiO or SiO) thin films fabricated by pulsed-laser ablation of silicon in the presence of oxygen pressure, from 10 to 0.5 mbar, are presented. X-ray diffraction spectra and Raman spectra confirmed the formation of nanocrystalline Si within the films while electron diffraction X-ray spectroscopy confirmed the increase in oxygen content with increasing O pressure.

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Ca ions play a fundamental role in cell death mediated by oxidative glutamate toxicity or oxytosis, a form of programmed cell death similar and possibly identical to other forms of cell death like ferroptosis. Ca influx from the extracellular space occurs late in a cascade characterized by depletion of the intracellular antioxidant glutathione, increases in cytosolic reactive oxygen species and mitochondrial dysfunction. Here, we aim to compare oxidative glutamate toxicity with ferroptosis, address the signaling pathways that culminate in Ca influx and cell death and discuss the proteins that mediate this.

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Mitofusin-2 (MFN2) is a GTPase in the outer mitochondrial membrane involved in the regulation of mitochondrial fusion and bioenergetics. MFN2 also plays a role in mitochondrial fusion induced by changes in the intracellular redox state. Adding oxidized glutathione (GSSG), the core cellular stress indicator, to mitochondrial preparations stimulates mitochondrial fusion by inducing disulphide bond-mediated oligomer formation of MFN2 and its homolog MFN1 which involve cysteine 684 (C684) of MFN2.

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Synaptic rearrangements during critical periods of postnatal brain development rely on the correct formation, strengthening, and elimination of synapses and associated dendritic spines to form functional networks. The correct balance of these processes is thought to be regulated by synapse-specific changes in the subunit composition of NMDA-type glutamate receptors (NMDARs). Among these, the nonconventional NMDAR subunit GluN3A has been suggested to play a role as a molecular brake in synaptic maturation.

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Drug-evoked synaptic plasticity in the mesolimbic dopamine (DA) system reorganizes neural circuits that may lead to addictive behavior. The first cocaine exposure potentiates AMPAR excitatory postsynaptic currents (EPSCs) onto DA neurons of the VTA but reduces the amplitude of NMDAR-EPSCs. While plasticity of AMPAR transmission is expressed by insertion of calcium (Ca(2+))-permeable GluA2-lacking receptors, little is known about the expression mechanism for altered NMDAR transmission.

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Ten aliphatic and aromatic ketals of arjunolic acid, a renewable, nanosized triterpenic acid which is obtainable from Terminalia arjuna, have been synthesized upon condensation with aldehydes. Self-assembly properties of the ketals have been studied in a wide range of organic liquids. With the exception of the p-nitrobenzylidene derivative, low concentrations of the ketals self-assemble and form gel-like dispersions in many of the organic liquids examined.

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Nine esters of a naturally occurring triterpenoid, arjunolic acid (from Terminalia arjuna), with alkyl chains have been synthesized, and their self-assembly has been studied in organic liquids. All of the esters examined were found to be excellent gelators. No birefringence was detected in optical micrographs of the transparent toluene gels with 5% (w/w) ethyl arjunolate or 5% (w/w) p-nitrobenzyl arjunolate as the gelator, but a spherulitic-type pattern was seen for a gel of 1.

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While separating two natural nano-sized triterpenic acids via bromolactonization, we serendipitously discovered that arjuna-bromolactone is an excellent gelator of various organic solvents. A simple and efficient method for the separation of two triterpenic acids and the gelation ability and solid state 1D-helical self-assembly of nano-sized arjuna-bromolactone are reported.

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