134 results match your criteria: "St. Petersburg State Polytechnical University[Affiliation]"

The expansion of glutamine residue track (polyQ) within soluble proteins (Q proteins) is responsible for nine autosomal-dominant genetic neurodegenerative disorders. These disorders develop when polyQ expansion exceeds a specific pathogenic threshold (Q) which is unique for each disease. However, the pathogenic mechanisms associated with the variability of Q within the family of Q proteins are poorly understood.

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The energy distributions of scattered and re-emitted low-energy positrons from a W(100) surface were measured as a function of incident positron energy from 0 to 25 eV. Given that tungsten has a negative work function of about -3 eV for positrons, one can envisage three scenarios of very low-energy positron scattering from such a surface. First, a positron approaching the sample surface with energy say 1 eV above the vacuum level will see a potential barrier of about 2 eV height and will be reflected back to the vacuum.

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The sigma 1 receptor (S1R) is a 223-amino-acid-long transmembrane endoplasmic reticulum (ER) protein. The S1R plays an important role in neuronal health and it is an established therapeutic target for neurodegenerative and neuropsychiatric disorders. Despite its importance in physiology and disease, the biological function of S1R is poorly understood.

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Alzheimer's disease (AD) is the most common cause of dementia. There is a growing body of evidence that dysregulation in neuronal calcium (Ca) signaling plays a major role in the initiation of AD pathogenesis. In particular, it is well established that Ryanodine receptor (RyanR) expression levels are increased in AD neurons and Ca release via RyanRs is augmented in AD neurons.

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Proteolytic processing of amyloid precursor protein (APP) plays a critical role in pathogenesis of Azheimer's disease (AD). Sequential cleavage of APP by β- and γ-secretases leads to generation of Aβ40 (non-amyloidogenic) and Aβ42 (amyloidogenic) peptides. Presenilin-1 (PS1) or presenilin-2 (PS2) act as catalytic subunits of γ-secretase.

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Alzheimer's disease - Where do we go from here?

Biochem Biophys Res Commun

December 2022

Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA; Laboratory of Molecular Neurodegeneration, Peter the Great St Petersburg State Polytechnical University, St. Petersburg, 195251, Russia. Electronic address:

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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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A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data.

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A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 and are not required to form a common vertex.

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Proteolytic processing of amyloid precursor protein (APP) plays a critical role in the pathogenesis of Alzheimer's disease (AD). Sequential cleavage of APP by β and γ secretases leads to the generation of Aβ40 (non-amyloidogenic) and Aβ42 (amyloidogenic) peptides. Presenilin-1 (PS1) or presenilin-2 (PS2) play the role of a catalytic subunit of γ-secretase.

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A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 at the CERN LHC, corresponding to an integrated luminosity of 137 collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented.

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The measurement of the luminosity recorded by the CMS detector installed at LHC interaction point 5, using proton-proton collisions at in 2015 and 2016, is reported. The absolute luminosity scale is measured for individual bunch crossings using beam-separation scans (the van der Meer method), with a relative precision of 1.3 and 1.

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A search is presented for a heavy vector resonance decaying into a boson and the standard model Higgs boson, where the boson is identified through its leptonic decays to electrons, muons, or neutrinos, and the Higgs boson is identified through its hadronic decays. The search is performed in a Lorentz-boosted regime and is based on data collected from 2016 to 2018 at the CERN LHC, corresponding to an integrated luminosity of 137 . Upper limits are derived on the production of a narrow heavy resonance , and a mass below 3.

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A search for charged Higgs bosons produced in vector boson fusion processes and decaying into vector bosons, using proton-proton collisions at at the LHC, is reported. The data sample corresponds to an integrated luminosity of 137 collected with the CMS detector. Events are selected by requiring two or three electrons or muons, moderate missing transverse momentum, and two jets with a large rapidity separation and a large dijet mass.

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This paper presents new sets of parameters ("tunes") for the underlying-event model of the event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in , and are obtained from a fit to minimum-bias data collected by the CMS experiment at , 7, and . The tunes are based on the NNPDF 3.

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Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and  + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and  + two-jet events are based on data collected at a center-of-mass energy of 8 , corresponding to an integrated luminosity of 19.

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Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 , corresponding to an integrated luminosity of 35.9 , are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model.

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Production cross sections of the Higgs boson are measured in the ( ) decay channel. A data sample of proton-proton collisions at a center-of-mass energy of 13 , collected by the CMS detector at the LHC and corresponding to an integrated luminosity of 137 is used. The signal strength modifier , defined as the ratio of the Higgs boson production rate in the channel to the standard model (SM) expectation, is measured to be at a fixed value of .

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The rate for Higgs ( ) bosons production in association with either one ( ) or two ( ) top quarks is measured in final states containing multiple electrons, muons, or tau leptons decaying to hadrons and a neutrino, using proton-proton collisions recorded at a center-of-mass energy of by the CMS experiment. The analyzed data correspond to an integrated luminosity of 137 . The analysis is aimed at events that contain , , or decays and each of the top quark(s) decays either to lepton+jets or all-jet channels.

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This work investigates the role of DNA binding by Runt in regulating the () gene and in particular two distinct -regulatory elements that mediate regulation by Runt and other pair-rule transcription factors during segmentation. We find that a DNA-binding-defective form of Runt is ineffective at repressing both the distal (DESE) and proximal (PESE) early stripe elements of and is also compromised for DESE-dependent activation. The function of Runt-binding sites in DESE is further investigated using site-specific transgenesis and quantitative imaging techniques.

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The production of Z boson pairs in proton-proton ( ) collisions, , where or , is studied at a center-of-mass energy of 13 with the CMS detector at the CERN LHC. The data sample corresponds to an integrated luminosity of 137 , collected during 2016-2018. The production cross section, , measured for events with two pairs of opposite-sign, same-flavor leptons produced in the mass region is consistent with standard model predictions.

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A decrease of two-gamma annihilation rate of a positron in a strong spin-orbit field of the annihilation site of bismuth impurity centerBi (= 9/2) in silicon with natural isotope composition was revealed (is the nuclear spin). This decrease was observed along with increasing occupancy of Bi donor states (binding energy{Bi} ≈ 69 meV). Atoms ofSi (= 1/2) isotope are involved in spin interactions of positron with Bi impurity centers.

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A search for dark matter particles is performed using events with a Z boson candidate and large missing transverse momentum. The analysis is based on proton-proton collision data at a center-of-mass energy of 13 , collected by the CMS experiment at the LHC in 2016-2018, corresponding to an integrated luminosity of 137 . The search uses the decay channels and .

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Association with proteasome determines pathogenic threshold of polyglutamine expansion diseases.

Biochem Biophys Res Commun

January 2021

Dept of Physiology, UT Southwestern Medical Center, Dallas, TX, 75390, USA; Laboratory of Molecular Neurodegeneration, St Petersburg State Polytechnical University, St Petersburg, 195251, Russian Federation. Electronic address:

Expansion of glutamine residue track (polyQ) within soluble protein is responsible for eight autosomal-dominant genetic neurodegenerative disorders. These disorders affect cerebellum, striatum, basal ganglia and other brain regions. Each disease develops when polyQ expansion exceeds a pathogenic threshold (Q).

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Chronic HBV infection results in various clinical manifestations due to different levels of immune response. In recent years, hepatitis B treatment has improved by long-term administration of nucleos(t)ide analogues (NUCs) and peg-interferon. Nucleic acid polymers (NAPs; REP 2139-Ca and REP 2139-Mg) are new antiviral drugs that block the assembly of subviral particles, thus preventing the release of HBsAg and allowing its clearance and restoration of functional control of infection when combined with various immunotherapies.

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