653 results match your criteria: "NRC "Kurchatov Institute"[Affiliation]"

This review considers the topological fermion condensation quantum phase transition (FCQPT) that explains the complex behavior of strongly correlated Fermi systems, such as frustrated insulators with quantum spin liquid and heavy fermion metals. The review contrasts theoretical consideration with recent experimental data collected on both heavy fermion metals (HF) and frustrated insulators. Such a method allows to understand experimental data.

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Using a data sample of proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of , the and decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to and , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of and mesons, .

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We report precision measurements of hypernuclei _{Λ}^{3}H and _{Λ}^{4}H lifetimes obtained from Au+Au collisions at sqrt[s_{NN}]=3.0  GeV and 7.2 GeV collected by the STAR experiment at the Relativistic Heavy Ion Collider, and the first measurement of _{Λ}^{3}H and _{Λ}^{4}H midrapidity yields in Au+Au collisions at sqrt[s_{NN}]=3.

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We report cumulants of the proton multiplicity distribution from dedicated fixed-target Au+Au collisions at sqrt[s_{NN}]=3.0  GeV, measured by the STAR experiment in the kinematic acceptance of rapidity (y) and transverse momentum (p_{T}) within -0.5 View Article and Find Full Text PDF

The first observation of the semileptonic b-baryon decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}, with a significance of 6.1σ, is reported using a data sample corresponding to 3  fb^{-1} of integrated luminosity, collected by the LHCb experiment at center-of-mass energies of 7 and 8 TeV at the LHC. The τ^{-} lepton is reconstructed in the hadronic decay to three charged pions.

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Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays are measured in intervals of the dilepton invariant mass squared. The measurements are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1} .

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The area-preserving rule for botanical trees by Leonardo da Vinci is discussed in terms of a very specific fractal structure, a logarithmic fractal. We use a method of the numerical Fourier analysis to distinguish the logarithmic fractal properties of the two-dimensional objects and apply it to study the branching system of real trees through its projection on the two-dimensional space, i.e.

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The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle.

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Two narrow resonant states are observed in the Λ_{b}^{0}K^{-}π^{+} mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6  fb^{-1}. The minimal quark content of the Λ_{b}^{0}K^{-}π^{+} system indicates that these are excited Ξ_{b}^{0} baryons. The masses of the Ξ_{b}(6327)^{0} and Ξ_{b}(6333)^{0} states are m[Ξ_{b}(6327)^{0}]=6327.

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Article Synopsis
  • The study examines charged particle production in proton-lead and proton-proton collisions at a center-of-mass energy of 5 TeV, focusing on how it varies with pseudorapidity and transverse momentum.
  • It finds that charged particle production is suppressed in proton-lead collisions compared to proton-proton in the forward region, while there's an increase in the backward region for higher transverse momentum values.
  • These findings provide valuable insights into nuclear parton distribution functions (PDFs) and saturation models, especially at low parton momentum fractions down to 10^{-6}.
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Parkinson's disease (PD) is a neurodegenerative disease characterised by the formation of Lewy bodies and progressive loss of dopaminergic (DA) neurons in the substantia nigra. Lewy bodies mainly consist of α-synuclein, which plays a critical role in the pathophysiology of PD. The α-synuclein is encoded by the gene and is the first identified gene associated with hereditary PD.

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A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 , at a center-of-mass energy .

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Pulse shape analysis in Gerda Phase II.

Eur Phys J C Part Fields

April 2022

Institute of Physics, Jagiellonian University, Cracow, Poland.

The GERmanium Detector Array (Gerda) collaboration searched for neutrinoless double- decay in Ge using isotopically enriched high purity germanium detectors at the Laboratori Nazionali del Gran Sasso of INFN. After Phase I (2011-2013), the experiment benefited from several upgrades, including an additional active veto based on LAr instrumentation and a significant increase of mass by point-contact germanium detectors that improved the half-life sensitivity of Phase II (2015-2019) by an order of magnitude. At the core of the background mitigation strategy, the analysis of the time profile of individual pulses provides a powerful topological discrimination of signal-like and background-like events.

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Neuroepigenetic Mechanisms of Action of Ultrashort Peptides in Alzheimer's Disease.

Int J Mol Sci

April 2022

Department of Molecular Radiation Biophysics, Petersburg Nuclear Physics Institute Named after B.P. Konstantinov, NRC "Kurchatov Institute", 188300 Gatchina, Russia.

Epigenetic regulation of gene expression is necessary for maintaining higher-order cognitive functions (learning and memory). The current understanding of the role of epigenetics in the mechanism of Alzheimer's disease (AD) is focused on DNA methylation, chromatin remodeling, histone modifications, and regulation of non-coding RNAs. The pathogenetic links of this disease are the misfolding and aggregation of tau protein and amyloid peptides, mitochondrial dysfunction, oxidative stress, impaired energy metabolism, destruction of the blood-brain barrier, and neuroinflammation, all of which lead to impaired synaptic plasticity and memory loss.

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Nitrobenzenesulfochlorination of β-aminopropioamidoximes leads to a set of products depending on the structure of the initial interacting substances and reaction conditions. Amidoximes, functionalized at the terminal C atom with six-membered -heterocycles (piperidine, morpholine, thiomorpholine and phenylpiperazine), as a result of the spontaneous intramolecular heterocyclization of the intermediate reaction product of an S2 substitution of a hydrogen atom in the oxime group of the amidoxime fragment by a nitrobenzenesulfonyl group, produce spiropyrazolinium or -nitrobenzenesulfonates. An exception is -nitrobenzenesulfochlorination of β-(thiomorpholin-1-yl)propioamidoxime, which is regioselective at room temperature, producing two spiropyrazolinium salts (-nitrobezenesulfonate and chloride), and regiospecific at the boiling point of the solvent, when only chloride is formed.

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Ribosomal protein S18 acetyltransferase RimI is responsible for the acetylation of elongation factor Tu.

J Biol Chem

May 2022

Department of Chemistry, Lomonosov Moscow State University, Moscow, Russia; Center of Life Sciences, Skolkovo Institute for Science and Technology, Moscow, Russia; Department of RNA Structure and Functions, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow, Russia; Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, Russia. Electronic address:

N-terminal acetylation is widespread in the eukaryotic proteome but in bacteria is restricted to a small number of proteins mainly involved in translation. It was long known that elongation factor Tu (EF-Tu) is N-terminally acetylated, whereas the enzyme responsible for this process was unclear. Here, we report that RimI acetyltransferase, known to modify ribosomal protein S18, is likewise responsible for N-acetylation of the EF-Tu.

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The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.

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Understanding gluon density distributions and how they are modified in nuclei are among the most important goals in nuclear physics. In recent years, diffractive vector meson production measured in ultraperipheral collisions (UPCs) at heavy-ion colliders has provided a new tool for probing the gluon density. In this Letter, we report the first measurement of J/ψ photoproduction off the deuteron in UPCs at the center-of-mass energy sqrt[s_{NN}]=200  GeV in d+Au collisions.

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Nanomechanical characterization of exosomes and concomitant nanoparticles from blood plasma by PeakForce AFM in liquid.

Biochim Biophys Acta Gen Subj

July 2022

Department of Medical and Biological Physics, Gomel State Medical University, 5, Lange St., 246000 Gomel, Belarus; Institute of Radiobiology of NAS of Belarus, 4, Fedyuninskogo St., 246007 Gomel, Belarus.

Background: To date, EVs characterization techniques are extremely diverse. The contribution of AFM, in particular, is often confined to size distribution. While AFM provides a unique possibility to carry out measurements in situ, nanomechanical characterization of EVs is still missing.

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COVID-19 treatment remains a challenge for medicine because of the extremely short time for clinical studies of drug candidates, so the drug repurposing strategy, which implies the use of well-known and safe substances, is a promising approach. We present the results of an observational clinical study that focused on the influence of riboflavin (vitamin B2) supplementation on the immune markers of COVID-19 severity in patients with mental health disorders. We have found that 10 mg of flavin mononucleotide (a soluble form of riboflavin) intramuscularly twice a day within 7 days correlated with the normalization of clinically relevant immune markers (neutrophils and lymphocytes counts, as well as their ratio) in COVID-19 patients.

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Antarctic sea-ice is exposed to a wide range of environmental conditions during its annual existence; however, there is very little information describing the change in sea-ice-associated microbial communities (SIMCOs) during the changing seasons. It is well known that during the solar seasons, SIMCOs play an important role in the polar carbon-cycle, by increasing the total photosynthetic primary production of the South Ocean and participating in the remineralization of phosphates and nitrogen. What remains poorly understood is the dynamic of SIMCO populations and their ecological contribution to carbon and nutrient cycling throughout the entire annual life of Antarctic sea-ice, especially in winter.

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Article Synopsis
  • This article discusses the analysis of groomed jet substructure in proton-proton (pp) and lead-lead (Pb-Pb) collisions using the ALICE detector at a collision energy of 5.02 TeV.
  • The study employs a soft drop grooming algorithm to isolate hard parton splittings and measures the groomed jet momentum splitting fraction and radius, revealing distinct behavior in jet structure under different collision conditions.
  • Notably, a narrowing of the groomed jet radius distribution in Pb-Pb collisions suggests changes in jet angular structure due to quark-gluon plasma, while no significant differences are observed in momentum splitting fractions, contributing valuable insights into jet energy-loss mechanisms.
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Genetically encoded monomeric blue-to-red fluorescent timers (mFTs) change their fluorescent color over time. mCherry-derived mFTs were used for the tracking of the protein age, visualization of the protein trafficking, and labeling of engram cells. However, the brightness of the blue and red forms of mFTs are 2-3- and 5-7-fold dimmer compared to the brightness of the enhanced green fluorescent protein (EGFP).

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The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field due to imbalanced chirality of quarks in local parity and charge-parity violating domains in quantum chromodynamics. The experimental measurement of the charge separation is made difficult by the presence of a major background from elliptic azimuthal anisotropy. This background and the CME signal have different sensitivities to the spectator and participant planes, and could thus be determined by measurements with respect to these planes.

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Article Synopsis
  • - The Borexino detector at Laboratori Nazionali del Gran Sasso successfully measured sub-MeV solar neutrinos using Cherenkov radiation and a technique linking photon hits to the Sun's position.
  • - In the energy range of 0.54 to 0.74 MeV, they detected 10,887 solar neutrinos from a total of 19,904 events, indicating a neutrino interaction rate consistent with standard solar model predictions.
  • - This groundbreaking measurement showcases the use of directional Cherenkov information in liquid scintillator detectors, paving the way for future hybrid methods that utilize both Cherenkov and scintillation signals in neutrino research.
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