Модификация физико-химических свойств биосовместимых полимеров методом ионной имплантации

В данной работе было рассмотрено влияние ионной имплантации ионов серебра, цинка и магния с экспозиционными дозами 110‘^ и ион/см^ на поверхностные свойства поливиниловог

A Large Hadron Electron Collider at CERN

This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb$^{-1}$. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC

Breast cancer associated with pregnancy

Introduction. The problem of breast cancer associated with pregnancy for a long time attracts close attention. The incidence is relatively increasing, thanks in part to improved detection methods, but also to the growing trend towards late childbearingЦель исследования — оценить влияние беременности на отдаленный прогноз и клиническое течение рака молочной желез

Vms1 and ANKZF1 peptidyl-tRNA hydrolases release nascent chains from stalled ribosomes

Ribosomal surveillance pathways scan for ribosomes that are transiently paused or terminally stalled owing to structural elements in mRNAs or nascent chain sequences. Some stalls in budding yeast are sensed by the GTPase Hbs1, which loads Dom34, a catalytically inactive member of the archaeo-eukaryotic release factor 1 superfamily. Hbs1–Dom34 and the ATPase Rli1 dissociate stalled ribosomes into 40S and 60S subunits. However, the 60S subunits retain the peptidyl-tRNA nascent chains, which recruit the ribosome quality control complex that consists of Rqc1–Rqc2–Ltn1–Cdc48–Ufd1–Npl4. Nascent chains ubiquitylated by the E3 ubiquitin ligase Ltn1 are extracted from the 60S subunit by the ATPase Cdc48–Ufd1–Npl4 and presented to the 26S proteasome for degradation. Failure to degrade the nascent chains leads to protein aggregation and proteotoxic stress in yeast and neurodegeneration in mice. Despite intensive investigations on the ribosome quality control pathway, it is not known how the tRNA is hydrolysed from the ubiquitylated nascent chain before its degradation. Here we show that the Cdc48 adaptor Vms1 is a peptidyl-tRNA hydrolase. Similar to classical eukaryotic release factor 1, Vms1 activity is dependent on a conserved catalytic glutamine. Evolutionary analysis indicates that yeast Vms1 is the founding member of a clade of eukaryotic release factor 1 homologues that we designate the Vms1-like release factor 1 clade

Topologically nontrivial phase-change compound GeSb2Te4

Chalcogenide phase-change materials show strikingly contrasting optical and electrical properties, which has led to their extensive implementation in various memory devices. By performing spin-, time-, and angle-resolved photoemission spectroscopy combined with the first-principles calculation, we report the experimental results that the crystalline phase of GeSb2Te4 is topologically nontrivial in the vicinity of the Dirac semimetal phase. The resulting linearly dispersive bulk Dirac-like bands that cross the Fermi level and are thus responsible for conductivity in the stable crystalline phase of GeSb2Te4 can be viewed as a 3D analogue of graphene. Our finding provides us with the possibility of realizing inertia-free Dirac currents in phase-change materials.The ARPES experiments were performed with the approval of the Proposal Assessing Committee of HSRC (Proposal No. 18BG039). The TARPES measurements were jointly carried out by the Laser and Synchrotron Research Center of the Institute for Solid State Physics at the University of Tokyo. This work was financially supported by KAKENHI (Grant No. 17H06138, No. 17H06152, No. 18H03683, No. 18H01148). This work was also supported by the ‘‘Tomsk State University competitiveness improvement programme’’ (Project No. 8.1.01.2018), by Saint Petersburg State University (Project ID 51126254), and by Russian Science Foundation No. 17-12-01047 (in the crystal growth part). T.V.M. and I.P.R. acknowledge support from Ministry of Education and Science of the Russian Federation (State Task No. 0721-2020-0033) (study of intermixed crystalline phase of GST-124). Calculations were performed at the SKIF-Cyberia supercomputer of Tomsk State University (Russian Federation). K.A.K. acknowledges RFBR Grant 17-08-00955 and a state contract of IGM SB RAS.Peer reviewe

Клинико-генетические характеристики понтоцеребеллярной гипоплазии, обусловленной мутациями в гене TSEN54 (OMIM: 277470)

Introduction. The description of the clinical and genetic characteristics of eight patients with autosomal-recessive variant pontocerebellar hypoplasia due to mutations in the TSEN54 gene.Purpose. Description of clinical and genetic characteristics of Russian patients with type 2A and type 4 of pontocerebellar hypoplasia.Materials and methods. The diagnosis of pontocerebellar hypoplasia was established on the basis of the specific features of clinical manifestations and detection of mutations in the gene TSEN54 based on the analysis of the results of exome sequencing. Results. 8 patients with pontocerebellar hypoplasia caused by mutations in the TSEN54 gene were identified. Discussion. Based on the features of clinical manifestations and severity of the disease in 5 patients diagnosed pontocerebellar hypoplasia type 2A, and in 3 patients – type 4. In patients with type 2A of pontocerebellar hypoplasia discovered mutation c. 919G>T (p.Ala307Ser)  in a homozygous state. Patients with type 4 of pontocerebellar hypoplasia this mutation is detected in the compound heterozygous state with c.670_671delAA (p.Lys224fs) and c.1264C>T (p.Gln422fs).Conclusion. The obtained results allow us to conclude that, as well as in European populations, the mutation c.919G>T (p. Ala307Ser) is a major in Russian patients with pontocerebellar hypoplasia 2A and 4 types, which account for about half of all cases of this disease group. The search for this mutation should be the first stage of molecular genetic diagnosis in patients with clinical and magnetic resonance signs of pontocerebellar hypoplasia.Введение. Представлено описание клинико-генетических характеристик 8 больных с аутосомно-рецессивным вариантом понтоцеребеллярных гипоплазий, обусловленных мутациями в гене TSEN54.Цель исследования – описание клинико-генетических характеристик российских больных с понтоцеребеллярной гипоплазией 2А и 4 типа.Материалы и методы. Диагноз понтоцеребеллярной гипоплазии устанавливался на основании особенностей клинических проявлений и обнаружения мутаций в гене ТSEN54 путем анализа результатов секвенирования экзома.Результаты. Выявлено 8 больных с понтоцеребеллярной гипоплазией, обусловленной мутациями в гене ТSEN54.Заключение. На основании особенностей клинических проявлений и тяжести течения заболевания у 5 больных диагностирована понтоцеребеллярная гипоплазия 2А типа, а у 3 больных – 4 типа. У больных с понтоцеребеллярной гипоплазией 2А типа обнаружена мутация с.919G>T (p.Ala307Ser) в гомозиготном состоянии. У больных с типом 4 эта мутация обнаружена в компаундгетерозиготном состоянии с мутациями c.670_671delAA (p.Lys224fs) и c.1264C>T (p.Gln422fs).Заключение. Полученные результаты позволяют сделать заключение, что, так же как и в европейских популяциях, мутация с.919G>T (p.Ala307Ser) является мажорной у российских больных с понтоцеребеллярной гипоплазией 2А и 4 типа, на долю которых приходится около половины всех случаев этой группы заболеваний. Поиск этой мутации должен быть первым этапом проведения молекулярно-генетической диагностики у больных с клиническими и магнитно-резонансными признаками понтоцеребеллярной гипоплазии

The Cryo-EM Structure of a Complete 30S Translation Initiation Complex from Escherichia coli

Formation of the 30S initiation complex (30S IC) is an important checkpoint in regulation of gene expression. The selection of mRNA, correct start codon, and the initiator fMet-tRNAfMet requires the presence of three initiation factors (IF1, IF2, IF3) of which IF3 and IF1 control the fidelity of the process, while IF2 recruits fMet-tRNAfMet. Here we present a cryo-EM reconstruction of the complete 30S IC, containing mRNA, fMet-tRNAfMet, IF1, IF2, and IF3. In the 30S IC, IF2 contacts IF1, the 30S subunit shoulder, and the CCA end of fMet-tRNAfMet, which occupies a novel P/I position (P/I1). The N-terminal domain of IF3 contacts the tRNA, whereas the C-terminal domain is bound to the platform of the 30S subunit. Binding of initiation factors and fMet-tRNAfMet induces a rotation of the head relative to the body of the 30S subunit, which is likely to prevail through 50S subunit joining until GTP hydrolysis and dissociation of IF2 take place. The structure provides insights into the mechanism of mRNA selection during translation initiation

Potential Gains from Mergers in Local Public Transport: An Efficiency Analysis Applied to Germany

We analyze potential gains from hypothetical mergers in local public transport using the non-parametric Data Envelopment Analysis with bias corrections by means of bootstrapping. Our sample consists of 41 public transport companies from Germany's most densely populated region, North Rhine-Westphalia. We merge them into geographically meaningful, larger units that operate partially on a joint tram network. Merger gains are then decomposed into individual technical efficiency, synergy and size effects following the methodology of Bogetoft and Wang [Bogetoft, P., Wang, D., 2005. Estimating the Potential Gains from Mergers. Journal of Productivity Analysis, 23(2), 145-171]. Our empirical findings suggest that substantial gains up to 16 percent of factor inputs are present, mainly resulting from synergy effects

The Large Hadron-Electron Collider at the HL-LHC

The Large Hadron-Electron Collider (LHeC) is designed to move the field of deep inelastic scattering (DIS) to the energy and intensity frontier of particle physics. Exploiting energy-recovery technology, it collides a novel, intense electron beam with a proton or ion beam from the High-Luminosity Large Hadron Collider (HL-LHC). The accelerator and interaction region are designed for concurrent electron-proton and proton-proton operations. This report represents an update to the LHeC's conceptual design report (CDR), published in 2012. It comprises new results on the parton structure of the proton and heavier nuclei, QCD dynamics, and electroweak and top-quark physics. It is shown how the LHeC will open a new chapter of nuclear particle physics by extending the accessible kinematic range of lepton-nucleus scattering by several orders of magnitude. Due to its enhanced luminosity and large energy and the cleanliness of the final hadronic states, the LHeC has a strong Higgs physics programme and its own discovery potential for new physics. Building on the 2012 CDR, this report contains a detailed updated design for the energy-recovery electron linac (ERL), including a new lattice, magnet and superconducting radio-frequency technology, and further components. Challenges of energy recovery are described, and the lower-energy, high-current, three-turn ERL facility, PERLE at Orsay, is presented, which uses the LHeC characteristics serving as a development facility for the design and operation of the LHeC. An updated detector design is presented corresponding to the acceptance, resolution, and calibration goals that arise from the Higgs and parton-density-function physics programmes. This paper also presents novel results for the Future Circular Collider in electron-hadron (FCC-eh) mode, which utilises the same ERL technology to further extend the reach of DIS to even higher centre-of-mass energies.Peer reviewe