287 research outputs found
Molecular CP-violating magnetic moment
A concept of CP-violating (T,P-odd) permanent molecular magnetic moments
is introduced. We relate the moments to the electric dipole moment
of electron (eEDM) and estimate for several diamagnetic polar
molecules. The moments exhibit a steep, Z^5, scaling with the nuclear charge Z
of the heavier molecular constituent. A measurement of the CP-violating
magnetization of a polarized sample of heavy molecules may improve the present
limit on eEDM by several orders of magnitude.Comment: 4 pages, no figures, submitted to PR
Association of C3435T (rs1045642) polymorphism of the MDR1 gene with the increased risk of colorectal cancer in russian females from Central Russia
The objective of this study was to examine associations of single nucleotide polymorphisms, rs1045642 within the MDR1 gene and rs1799930 within the NAT2 gene, with the risk of colorectal cancer (CRC) in the population of Central Russi
Genetic mechanisms of the influence of light and phototransduction on Drosophila melanogaster lifespan
The light of the visible spectrum (with wavelengths of 380-780 nm) is one of the fundamental abiotic factors to which organisms have been adapting since the start of biological evolution on the Earth. Numerous literature sources establish a connection between the duration of exposure to daylight, carcinogenesis and longevity, convincingly showing a significant reduction in the incidence of cancer in blind people, as well as in animal models. On the other hand, the stimulating nature of the effect of continuous illumination on reproductive function was noted, in particular, the effects of increasing the fecundity of females of various species are known. Increase in motor activity and, as a result, in metabolic rate and thermogenesis during permanent exposure to light also reduces the body's energy reserves and lifespan. In principle, in the context of aging, not only the exposure time, but also the age at the onset of exposure to constant illumination matter, the reverse effects are valid for the maintenance of experimental animals in the constant darkness. Over the long period of the evolution of light signal transduction systems, many mechanisms have emerged that allow to form an adequate response of the organism to illumination, modulating the highly conservative signaling cascades, including those associated with aging and lifespan (FOXO, SIRT1, NF-kB, mTOR/S6k, PPARa, etc). In this review, we consider the relationship between lifespan, photoregimens, and also the expression of the genes encoding the phototransduction cascade and the circadian oscillator elements of animal cells. In the present paper, basic transducers of light and other signals, such as the family of TRP receptors, G proteins, phospholipase C, and others, are considered in the context of aging and longevity. A relationship between the mechanisms of thermoreception, the temperature synchronization of the circadian oscillator and the life span is established in the review. Analysis of experimental data obtained from the Drosophila melano-gaster model allowed us to formulate the hypothesis of age-dependent photoresistance - a gradual decrease in the expression of genes associated with phototransduction and circadian oscillators, leading to deterioration in the ability to adapt to the photoregimen and to the increase in the rate of aging
High-Q trenched aluminum coplanar resonators with an ultrasonic edge microcutting for superconducting quantum devices
Dielectric losses are one of the key factors limiting the coherence of
superconducting qubits. The impact of materials and fabrication steps on
dielectric losses can be evaluated using coplanar waveguide (CPW) microwave
resonators. Here, we report on superconducting CPW microwave resonators with
internal quality factors systematically exceeding 5x106 at high powers and
2x106 (with the best value of 4.4x106) at low power. Such performance is
demonstrated for 100-nm-thick aluminum resonators with 7-10.5 um center trace
on high-resistivity silicon substrates commonly used in quantum Josephson
junction circuits. We investigate internal quality factors of the resonators
with both dry and wet aluminum etching, as well as deep and isotropic reactive
ion etching of silicon substrate. Josephson junction compatible CPW resonators
fabrication process with both airbridges and silicon substrate etching is
proposed. Finally, we demonstrate the effect of airbridges positions and extra
process steps on the overall dielectric losses. The best quality fa ctors are
obtained for the wet etched aluminum resonators and isotropically removed
substrate with the proposed ultrasonic metal edge microcutting.Comment: 6 pages, 2 figure
(S)-2-Amino-2-(2-chlorophenyl)cyclohexanone
The crystal structure of the title compound, C12H14ClNO, was determined in order to confirm that the chiral center of the molecule has an S configuration. The cyclohexanone ring adopts a chair conformation. The 2-chlorophenyl ring is slightly twisted from the axial C—N bond, with a N—C—C—C torsion angle of −5.7 (2)°. In the crystal, an intermolecular N—H⋯O hydrogen bond links adjacent molecules into an infinite chain, which propagates in the b-axis direction
Broadband SNAIL parametric amplifier with microstrip impedance transformer
Josephson parametric amplifiers have emerged as a promising platform for
quantum information processing and squeezed quantum states generation.
Travelling wave and impedance-matched parametric amplifiers provide broad
bandwidth for high-fidelity single-shot readout of multiple qubit
superconducting circuits. Here, we present a quantum-limited 3-wave-mixing
parametric amplifier based on superconducting nonlinear asymmetric inductive
elements (SNAILs), whose useful bandwidth is enhanced with an on-chip
two-section impedance-matching circuit based on microstrip transmission lines.
The amplifier dynamic range is increased using an array of sixty-seven SNAILs
with 268 Josephson junctions, forming a nonlinear quarter-wave resonator.
Operating in a current-pumped mode, we experimentally demonstrate an average
gain of across bandwidth, along with an average saturation
power of , which can go as high as with quantum-limited
noise performance. Moreover, the amplifier can be fabricated using a simple
technology with just a one e-beam lithography step. Its central frequency is
tuned over a several hundred megahertz, which in turn broadens the effective
operational bandwidth to around .Comment: 7 pages, 3 figure
Improving Josephson junction reproducibility for superconducting quantum circuits: junction area fluctuation
Josephson superconducting qubits and parametric amplifiers are prominent
examples of superconducting quantum circuits that have shown rapid progress in
recent years. With the growing complexity of such devices, the requirements for
reproducibility of their electrical properties across a chip have become
stricter. Thus, the critical current variation of the Josephson junction,
as the most important electrical parameter, needs to be minimized. Critical
current, in turn, is related to normal-state resistance the Ambegaokar-Baratoff
formula, which can be measured at room temperature. Here, we focus on the
dominant source of Josephson junction critical current non-uniformity junction
area variation. We optimized Josephson junctions fabrication process and
demonstrate resistance variation of and across
and chip areas, respectively. For a
wide range of junction areas from to we
ensure a small linewidth standard deviation of measured over 4500
junctions with linear dimensions from to . The developed process
was tested on superconducting highly coherent transmon qubits and a nonlinear asymmetric inductive element parametric
amplifier
Genetics of aging and longevity
Lifespan is a complex quantitative characteristic that makes a significant contribution to the Darwinian adaptiveness. The disclosure of the genetic structure of longevity is a fundamental problem of the evolution of ontogeny, evolutionary genetics and molecular gerontology. Under optimal conditions, the lifespan is determined by the aging rate. The aging process is made up of interrelated processes that take place at the organismal, tissue, cellular, molecular and genetic levels. These include deregulation processes of homeostasis maintenance, metabolic reactions and sending intra- and intercellular signals, accumulation of senescent cells, damaged organelles and macromolecules, epigenetic changes and genetic instability. The objective of this review is to summarize the available information about underlying genetic determinants of longevity and aging. Genes and signaling pathways that regulate stress response, metabolism, growth of cells and organism, maintaining of genome and proteome integrity, qualitative and quantitative mitochondria composition, inflammatory response, apoptosis and selection of viable cells, as well as circadian rhythms were considered. The redistribution of energy resources from one pathway to the other can induce or inhibit the ”longevity program”, providing increased vitality and aging slowdown. Based on the analysis of geroprotective potential of examined genes’ regulation, main targets have been identified to slowdown aging and achieve healthy longevity. These trends include heterochromatin recovery, retrotransposition suppression, aneuploidy elimination; restoring the acidity of lysosomes; telomere elongation; suppression of chronic inflammation; elimination of protein cross-links; elimination of senescent cells; recovery of NAD+ levels; inhibition of mTOR, S6K, TGF-β, AT1; controlled activation of the ”longevity program” genes FOXO, AMPK, PGC1α, NRF2
Partial Structural transformation of NiMn in Exchange biased Fe20Ni80/Ni30Mn70/Fe20Ni80 thin films
Features of crystal structure and exchange bias of annealed Fe20Ni80/Ni30Mn70/Fe20Ni80 thin films are investigated. Temperature dependences of hysteresis loops reveal that for a sample with a thicker FeNi bottom layer a blocking temperature exceeds a Néel temperature of A1 -NiMn by 20K, while for a sample with a thinner FeNi bottom layer a blocking tem-perature is larger than the Néel temperature by 140K. An explanation of the influence of the bottom FeNi layer on the phase transformation in NiMn is proposed.This work was financially supported by the Russian Science Foundation (RSF), project No. 18-72-10044
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