104 research outputs found
Tracer diffusion inside fibrinogen layers
We investigate the obstructed motion of tracer (test) particles in crowded
environments by carrying simulations of two-dimensional Gaussian random walk in
model fibrinogen monolayers of different orientational ordering. The fibrinogen
molecules are significantly anisotropic and therefore they can form structures
where orientational ordering, similar to the one observed in nematic liquid
crystals, appears. The work focuses on the dependence between level of the
orientational order (degree of environmental crowding) of fibrinogen molecules
inside a layer and non-Fickian character of the diffusion process of spherical
tracer particles moving within the domain. It is shown that in general
particles motion is subdiffusive and strongly anisotropic, and its
characteristic features significantly change with the orientational order
parameter, concentration of fibrinogens and radius of a diffusing probe.Comment: 8 pages, 12 figure
Wide-range Angle-sensitive Plasmonic Color Printing on Lossy-Resonator Substrates
We demonstrate a sustainable, lithography-free process for generating non
fading plasmonic colors with a prototype device that produces a wide range of
vivid colors in red, green, and blue (RGB) ([0-1], [0-1], [0-1]) color space
from violet (0.7, 0.72, 1) to blue (0.31, 0.80, 1) and from green (0.84, 1,
0.58) to orange (1, 0.58, 0.46). The proposed color-printing device
architecture integrates a semi-transparent random metal film (RMF) with a metal
back mirror to create a lossy asymmetric Fabry-P\'erot resonator. This device
geometry allows for advanced control of the observed color through the
five-degree multiplexing (RGB color space, angle, and polarization
sensitivity). An extended color palette is then obtained through
photomodification process and localized heating of the RMF layer under various
femtosecond laser illumination conditions at the wavelengths of 400 nm and 800
nm. Colorful design samples with total areas up to 10 mm2 and 100 {\mu}m
resolution are printed on 300-nm-thick films to demonstrate macroscopic
high-resolution color generation. The proposed printing approach can be
extended to other applications including laser marking, anti-counterfeiting and
chromo-encryption
Chiral doublers of heavy-light baryons
We discuss the consequences of the chiral doubling scenario for baryons built
of heavy and light quarks. In particular, we use the soliton description for
baryons, demonstrating why each heavy-light baryon should be accompanied by the
opposite parity partner. Our argumentation holds both for ordinary baryons and
for exotic heavy pentaquarks which are required by the symmetries of QCD to
appear in parity doublets, seperated by the mass shift of the chiral origin.
Interpreting the recently observed by BaBaR, CLEO and Belle charmed mesons with
assignment as the chiral partners of known and mesons,
allows us to estimate the parameters of the mesonic effective lagrangian, and
in consequence, estimate the masses of ground states and excited states of both
parities. In particular, we interpret the state recently reported by the H1
experiment at HERA as a chiral partner of yet
undiscovered ground state pentaquark .Comment: 10 pages, in v2 some typos corrected, references adde
Conserved structures and dynamics in 5'-proximal regions of Betacoronavirus RNA genomes
Betacoronaviruses are a genus within the Coronaviridae family of RNA viruses. They are capable of infecting vertebrates and causing epidemics as well as global pandemics in humans. Mitigating the threat posed by Betacoronaviruses requires an understanding of their molecular diversity. The development of novel antivirals hinges on understanding the key regulatory elements within the viral RNA genomes, in particular the 5'-proximal region, which is pivotal for viral protein synthesis. Using a combination of cryo-electron microscopy, atomic force microscopy, chemical probing, and computational modeling, we determined the structures of 5'-proximal regions in RNA genomes of Betacoronaviruses from four subgenera: OC43-CoV, SARS-CoV-2, MERS-CoV, and Rousettus bat-CoV. We obtained cryo-electron microscopy maps and determined atomic-resolution models for the stem-loop-5 (SL5) region at the translation start site and found that despite low sequence similarity and variable length of the helical elements it exhibits a remarkable structural conservation. Atomic force microscopy imaging revealed a common domain organization and a dynamic arrangement of structural elements connected with flexible linkers across all four Betacoronavirus subgenera. Together, these results reveal common features of a critical regulatory region shared between different Betacoronavirus RNA genomes, which may allow targeting of these RNAs by broad-spectrum antiviral therapeutics.Peer reviewe
Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio
The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts
The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan
Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised protons
Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise. © 2015
Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons
Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS longitudinally polarised muon beam at 160GeV/c and a 6LiD target. The amplitudes of the three azimuthal modulations cos φh, cos 2φh and sin φh were obtained binning the data separately in each of the relevant kinematic variables x, z or pTh and binning in a three-dimensional grid of these three variables. The amplitudes of the cos φh and cos 2φh modulations show strong kinematic dependencies both for positive and negative hadrons. © 2014 CERN for the benefit of the COMPASS Collaboration
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