1,355 research outputs found
Revisiting the Sample Adaptive Offset post-filter of VVC with Neural-Networks
The Sample Adaptive Offset (SAO) filter has been introduced in HEVC to reduce
general coding and banding artefacts in the reconstructed pictures, in
complement to the De-Blocking Filter (DBF) which reduces artifacts at block
boundaries specifically. The new video compression standard Versatile Video
Coding (VVC) reduces the BD-rate by about 36% at the same reconstruction
quality compared to HEVC. It implements an additional new in-loop Adaptive Loop
Filter (ALF) on top of the DBF and the SAO filter, the latter remaining
unchanged compared to HEVC. However, the relative performance of SAO in VVC has
been lowered significantly. In this paper, it is proposed to revisit the SAO
filter using Neural Networks (NN). The general principles of the SAO are kept,
but the a-priori classification of SAO is replaced with a set of neural
networks that determine which reconstructed samples should be corrected and in
which proportion. Similarly to the original SAO, some parameters are determined
at the encoder side and encoded per CTU. The average BD-rate gain of the
proposed SAO improves VVC by at least 2.3% in Random Access while the overall
complexity is kept relatively small compared to other NN-based methods
IMM-BCP-01, a patient-derived anti-SARS-CoV-2 antibody cocktail, is active across variants of concern including Omicron BA.1 and BA.2
Monoclonal antibodies are an efficacious therapy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, rapid viral mutagenesis led to escape from most of these therapies, outlining the need for an antibody cocktail with a broad neutralizing potency. Using an unbiased interrogation of the memory B cell repertoire of patients with convalescent COVID-19, we identified human antibodies with broad antiviral activity in vitro and efficacy in vivo against all tested SARS-CoV-2 variants of concern, including Delta and Omicron BA.1 and BA.2. Here, we describe an antibody cocktail, IMM-BCP-01, that consists of three patient-derived broadly neutralizing antibodies directed at nonoverlapping surfaces on the SARS-CoV-2 Spike protein. Two antibodies, IMM20184 and IMM20190, directly blocked Spike binding to the ACE2 receptor. Binding of the third antibody, IMM20253, to its cryptic epitope on the outer surface of RBD altered the conformation of the Spike Trimer, promoting the release of Spike monomers. These antibodies decreased Omicron SARS-CoV-2 infection in the lungs of Syrian golden hamsters in vivo and potently induced antiviral effector response in vitro, including phagocytosis, ADCC, and complement pathway activation. Our preclinical data demonstrated that the three-antibody cocktail IMM-BCP-01 could be a promising means for preventing or treating infection of SARS-CoV-2 variants of concern, including Omicron BA.1 and BA.2, in susceptible individuals
Synthesis of AlMgB14: Effect of modes of mechanical activation of the raw powders on the properties of obtained materials
In work studies of phase composition, hardness and density of materials based on AlMgB14 synthesized by hot pressing method at temperatures of 1300 and 1400 °C under pressure 50 MPa from aluminum, magnesium and boron powders (E1 mixture), as well as from original powder of aluminum-magnesium alloy (E2 mixture) were conducted. AlMgB14 phase content of obtained bulk samples is ~ 95 wt. %. The maximum hardness of 14GPa and density of 2.1 g/cm3, respectively, has a sample, marked as E1, synthesized at a temperature of 1400 °C
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Laminography as a tool for imaging large-size samples with high resolution
Despite the increased brilliance of the new generation synchrotron sources, there is still a challenge with high-resolution scanning of very thick and absorbing samples, such as a whole mouse brain stained with heavy elements, and, extending further, brains of primates. Samples are typically cut into smaller parts, to ensure a sufficient X-ray transmission, and scanned separately. Compared with the standard tomography setup where the sample would be cut into many pillars, the laminographic geometry operates with slab-shaped sections significantly reducing the number of sample parts to be prepared, the cutting damage and data stitching problems. In this work, a laminography pipeline for imaging large samples (>1 cm) at micrometre resolution is presented. The implementation includes a low-cost instrument setup installed at the 2-BM micro-CT beamline of the Advanced Photon Source. Additionally, sample mounting, scanning techniques, data stitching procedures, a fast reconstruction algorithm with low computational complexity, and accelerated reconstruction on multi-GPU systems for processing large-scale datasets are presented. The applicability of the whole laminography pipeline was demonstrated by imaging four sequential slabs throughout an entire mouse brain sample stained with osmium, in total generating approximately 12 TB of raw data for reconstruction
Epstein-Barr virus induces adhesion molecule CD226 (DNAM-1) expression during primary B cell transformation into lymphoblastoid cell lines
AlN production in co-flow filtration mode at low pressures
In this work, the process for obtaining aluminum nitride in the combustion mode of co-flow filtration of a nitrogen–argon mixture was investigated. The combustion of granules consisting of aluminum and aluminum nitride as an inert diluent was studied under conditions of co-current filtration in a flow of nitrogen and a nitrogen–argon mixture in the range of a specific flow rate of 1.5–5.0 cm3/(scm2). It was found that the specific flow rate of the gas mixture and the amount of argon in the nitrogen–argon mixture had a significant effect on the rate and the temperature of combustion. The structure and phase composition of the synthesis products were studied. The maximum achieved yield of the AlN phase was 95 wt.%. Moreover, this method is energy efficient and allows the production of metal nitrides without the use of high-pressure reactors
Superintegrable systems with spin and second-order integrals of motion
We investigate a quantum nonrelativistic system describing the interaction of
two particles with spin 1/2 and spin 0, respectively. We assume that the
Hamiltonian is rotationally invariant and parity conserving and identify all
such systems which allow additional integrals of motion that are second order
matrix polynomials in the momenta. These integrals are assumed to be scalars,
pseudoscalars, vectors or axial vectors. Among the superintegrable systems
obtained, we mention a generalization of the Coulomb potential with scalar
potential and spin orbital one
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