Search for long-lived particles decaying to a pair of muons in proton-proton collisions at s \sqrt{s} = 13 TeV

An inclusive search for long-lived exotic particles decaying to a pair of muons is presented. The search uses data collected by the CMS experiment at the CERN LHC in proton-proton collisions at s√ = 13 TeV in 2016 and 2018 and corresponding to an integrated luminosity of 97.6 fb−1. The experimental signature is a pair of oppositely charged muons originating from a common secondary vertex spatially separated from the pp interaction point by distances ranging from several hundred μm to several meters. The results are interpreted in the frameworks of the hidden Abelian Higgs model, in which the Higgs boson decays to a pair of long-lived dark photons ZD, and of a simplified model, in which long-lived particles are produced in decays of an exotic heavy neutral scalar boson. For the hidden Abelian Higgs model with m(ZD) greater than 20 GeV and less than half the mass of the Higgs boson, they provide the best limits to date on the branching fraction of the Higgs boson to dark photons for cτ(ZD) (varying with m(ZD)) between 0.03 and ≈0.5 mm, and above ≈0.5 m. Our results also yield the best constraints on long-lived particles with masses larger than 10 GeV produced in decays of an exotic scalar boson heavier than the Higgs boson and decaying to a pair of muons

The role of the catalytic domain of E. coli GluRS in tRNAGln discrimination

Discrimination of tRNA(Gln) is an integral function of several bacterial glutamyl-tRNA synthetases (GluRS). The origin of the discrimination is thought to arise from unfavorable interactions between tRNA(Gln) and the anticodon-binding domain of GluRS. From experiments on an anticodon-binding domain truncated Escherichia coli (E. coli) GluRS (catalytic domain) and a chimeric protein, constructed from the catalytic domain of E. coli GluRS and the anticodon-binding domain of E. coli glutaminyl-tRNA synthetase (GlnRS), we show that both proteins discriminate against E. coli tRNA(Gln). Our results demonstrate that in addition to the anticodon-binding domain, tRNA(Gln) discriminatory elements may be present in the catalytic domain in E. coli GluRS as well

DFT Analyses of arsylsemicarbazone group as functional compound for application as excellent fluorescent probes and medicament: study on virtual screening through molecular docking

The present invention reports two novel functional compounds, 2-hydroxy-3-naphthaldehyde thiosemicarbazone (2H3NTS) and 2-hydroxy-3-naphthaldehyde semicarbazone (2H3NS), as plausible fuorescent probes possessing excited state intramolecular proton transfer property, and they are not yet reported to be synthesized by any research group. The DFT study reveals signifcantly higher Stokes shift (31,476 cm−1) for 2H3NS indicating swift relaxation from initial to the emissive state and reduces self-quenching from self-molecular absorption which favours its practical application. Consequently, successive in vitro activity of 2H3NTS and 2H3NS is studied in silico using molecular docking towards the inhibition capacity of target kinase protein like CDK, primarily responsible for cell growth. As expected, 2H3NS is capable of binding with both competitive ATP binding SITE I and non-competitive SITE II which lies below the T-loop, thereby inhibiting the cell growth and diferentiation. However, 2H3NTS with polarizable sulphur is incapable of binding at SITE I with selective inhibition posing the ATP site to be well conserved

Scope and challenges for green synthesis of functional nano particles

Nanoscience and nanotechnology are the most promising area of material science which interlaces various disciplines of science. This specific arena re-opens the imbibed properties of an already known system, e.g. metal, composite, etc., in a different manner so that the electron charge density waves termed as plasmons are getting generated and thereby perturbing the intensity of incident and reflected light in proportionate to the mass. Synthesis of nanoparticles through biological routes involves microorganisms, bacteria, fungi, plant/leaves extract, etc. The process can be carried out either in extracellular and/or intracellular mode. However, in general, bio-nanoparticles’ synthesis using plant extract tend to occur intracellularly and is kinetically fast compared to that of microbial synthesis. The bio-sources effectively act as a natural laboratory that accelerates the synthesis of variable nanoparticles, like metal, metal oxide, bimetallic oxide, etc. Plant crude extract contains novel secondary metabolites which are responsible for nanoparticle formation. In addition, such groups function as capping agents and thereby retaining the dimension of nanoparticles as required for a specific application. However, understanding the basic study of reaction kinetics for a particular plant extract/microbe-metal pair or influence of a specific plant extract on variable metals salts has not been undertaken precisely. The significance of such a study on fundamental aspects enables the selection of appropriate plant extract and leads to the tailoring of the morphology of the resultant nanoparticle. The primary task, however, is to determine and analyse the role of the exact constituent required for reducing and capping action. The challenge lies in whether certain bio-compounds need to be eliminated as per the requisite of bio-synthesis. The chapter herein provides a comprehensive study on the plants and microbe-mediated synthesis of functional nanoparticles, the associated parameters and their application. Finally, the significance of green synthesis toward toxicogenomics and the involved challenges are discussed in terms of the mechanistic approach

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Not AvailableHilsa (Tenualosa ilisha) is a clupeid that migrates from the off-shore area through the freshwater river for spawning. The purpose of this study was to investigate the involvement of branchial Na+/K+-ATPase (NKA) and Na+/K+/2Cl- cotransporter (NKCC) in maintaining ionic homeostasis in hilsa while moving across the salt barriers. Hilsa, migrating through marine and brackish waters, did not show any significant decline in NKA activity, plasma osmolality, and plasma ionic concentration. In contrast, all the parameters declined significantly, after the fish reached in freshwater zone of the river. Immunoblotting with NKA α antibody recognized two bands in gill homogenates. The intensity of the higher molecular NKA band decreased, while the other band subsequently increased accompanying the movement of hilsa from marine water (MW) to freshwater. Nevertheless, total NKA expression in marine water did not change prior to freshwater entry. NKCC expression was down-regulated in gill, parallel with NKA activity, as the fish approached to the freshwater stretch of river. The NKA α-1 and NKCC1 protein abundance decreased in freshwater individuals by 40% and 31%, respectively, compared to MW. NKA and NKCC1 were explicitly localized to branchial ionocytes and immunoreactive signal appeared throughout the cytoplasm except for the nucleus and the most apical region indicates a basolateral/tubular distribution. Immunoreactive ionocytes were distributed on the filaments and lamellae; lamellar ionocytes were more in number irrespective of habitat salinity. The decrease in salinity caused a slight reduction in ionocyte number, but not in size and the underlying distribution pattern did not alter. The overall results support previously proposed models that both the ion transporters are involved in maintaining ionic homeostasis and lamellar ionocytes may have the function in hypo-osmoregulation in migrating hilsa, unlike other anadromous teleosts.Not Availabl

A functional loop spanning distant domains of glutaminyl-tRNA synthetase also stabilizes a molten globule state

Molten globule and other disordered states of proteins are now known to play important roles in many cellular processes. From equilibrium unfolding studies of two paralogous proteins and their variants, glutaminyl-tRNA synthetase (GlnRS) and two of its variants [glutamyl-tRNA synthetase (GluRS) and its isolated domains, and a GluRS-GlnRS chimera], we demonstrate that only GlnRS forms a molten globule-like intermediate at low urea concentrations. We demonstrated that a loop in the GlnRS C-terminal anticodon binding domain that promotes communication with the N-terminal domain and indirectly modulates amino acid binding is also responsible for stabilization of the molten globule state. This loop was inserted into GluRS in the eukaryotic branch after the archaea-eukarya split, right around the time when GlnRS evolved. Because of the structural and functional importance of the loop, it is proposed that the insertion of the loop into a putative ancestral GluRS in eukaryotes produced a catalytically active molten globule state. Because of their enhanced dynamic nature, catalytically active molten globules are likely to possess broad substrate specificity. It is further proposed that the putative broader substrate specificity allowed the catalytically active molten globule to accept glutamine in addition to glutamic acid, leading to the evolution of GlnRS

Supramolecular Arrangement and DFT analysis of Zinc(II) Schiff Bases: An Insight towards the Influence of Compartmental Ligands on Binding Interaction with Protein

We report, for the first time, a detailed crystallographic study of the supramolecular arrangement for a set of zinc(II) Schiff base complexes containing the ligand 2,6-bis((E)-((2-(dimethylamino)ethyl)imino)methyl)-4-R-phenol], where R=methyl/tert-butyl/chloro. The supramolecular study acts as a pre-screening tool for selecting the compartmental ligand R of the Schiff base for effective binding with a targeted protein, bovine serum albumin (BSA). The most stable hexagonal arrangement of the complex Zn-Me] (R=Me) stabilises the ligand with the highest FMO energy gap (Delta E=4.22 eV) and lowest number of conformations during binding with BSA. In contrast, formation of unstable 3D columnar vertebra for Zn-Cl] (R=Cl) tend to activate the system with lowest FMO gap (3.75 eV) with highest spontaneity factor in molecular docking. Molecular docking analyses reported in terms of 2D LigPlot+ identified site A, a cleft of domains IB, IIIA and IIIB, as the most probable protein binding site of BSA. Arg144, Glu424, Ser428, Ile455 and Lys114 form the most probable interactions irrespective of the type of compartmental ligands R of the Schiff base whereas Arg185, Glu519, His145, Ile522 act as the differentiating residues with Delta G=-7.3 kcal mol(-1)

Characterization of DNA binding property of the HIV-1 host factor and tumor suppressor protein Integrase Interactor 1 (INI1/hSNF5).

Integrase Interactor 1 (INI1/hSNF5) is a component of the hSWI/SNF chromatin remodeling complex. The INI1 gene is either deleted or mutated in rhabdoid cancers like ATRT (Atypical terratoid and rhabdoid tumor). INI1 is also a host factor for HIV-1 replication. INI1 binds DNA non-specifically. However, the mechanism of DNA binding and its biological role are unknown. From agarose gel retardation assay (AGRA), Ni-NTA pull-down and atomic force microscopy (AFM) studies we show that amino acids 105-183 of INI1 comprise the minimal DNA binding domain (DBD). The INI1 DBD is absent in plants and in yeast SNF5. It is present in Caenorhabditis elegans SNF5, Drosophila melanogaster homologue SNR1 and is a highly conserved domain in vertebrates. The DNA binding property of this domain in SNR1, that is only 58% identical to INI1/hSNF5, is conserved. Analytical ultracentrifugation studies of INI1 DBD and INI1 DBD:DNA complexes at different concentrations show that the DBD exists as a monomer at low protein concentration and two molecules of monomer binds one molecule of DNA. At high protein concentration, it exists as a dimer and binds two DNA molecules. Furthermore, isothermal calorimetry (ITC) experiments demonstrate that the DBD monomer binds DNA with a stoichiometry (N) of ∼0.5 and Kd  = 0.94 µM whereas the DBD dimer binds two DNA molecules sequentially with K'd1 = 222 µM and K'd2 = 1.16 µM. Monomeric DBD binding to DNA is enthalpy driven (ΔH = -29.9 KJ/mole). Dimeric DBD binding to DNA is sequential with the first binding event driven by positive entropy (ΔH'1 = 115.7 KJ/mole, TΔS'1 = 136.8 KJ/mole) and the second binding event driven by negative enthalpy (ΔH'2 = -106.3 KJ/mole, TΔS'2 = -75.7 KJ/mole). Our model for INI1 DBD binding to DNA provides new insights into the mechanism of DNA binding by INI1

Phytochemicals as an active pharmaceutical ingredient of <i>Ocimum sanctum</i> and <i>Azadirachta indica</i>:a theoretical screening study

Plants, also known as Phyto, are the most abundant source of medications in traditional medicine, contemporary medicine, nutraceuticals, pharmaceutical intermediates, dietary supplements, and artificial synthesis reagents. Medicinal plants are a great source of nutrition and are bestowed by nature, and their variability is diverse in different parts of the world. Alkaloids, tannins, flavonoids, and phenolic chemicals are plants’ most significant chemically active (biologically active) elements. Flavonoids, tannins, terpenoids, and saponins are termed phytochemicals and are present in most wild plants’ leaves and stems. A simple but exciting domestic plant is Ocimum sanctum, while alkaloids are absent in it. In comparison, Neem (Azadirachta indica) has a wide range of active pesticide compounds known as “triterpenes,” or more precisely, “limonoids.” The present research article aims at theoretical DFT analyzes of selected phytochemicals like Epicatechin and Quercetin to study their reactivity pattern. Compared to other known phytochemicals in neem and Tulsi, these two are selected based on FMO formalism. This is followed by their molecular docking analyzes to study the interaction with BSA and CDK2 protein. Detailed hydrophobic analyzes are reported using these phytochemicals which enable effective prescreening prior to experimentation to establish them as an active pharmaceutical ingredient