3,413 research outputs found
Image Denoising using Attention-Residual Convolutional Neural Networks
During the image acquisition process, noise is usually added to the data
mainly due to physical limitations of the acquisition sensor, and also
regarding imprecisions during the data transmission and manipulation. In that
sense, the resultant image needs to be processed to attenuate its noise without
losing details. Non-learning-based strategies such as filter-based and noise
prior modeling have been adopted to solve the image denoising problem.
Nowadays, learning-based denoising techniques showed to be much more effective
and flexible approaches, such as Residual Convolutional Neural Networks. Here,
we propose a new learning-based non-blind denoising technique named Attention
Residual Convolutional Neural Network (ARCNN), and its extension to blind
denoising named Flexible Attention Residual Convolutional Neural Network
(FARCNN). The proposed methods try to learn the underlying noise expectation
using an Attention-Residual mechanism. Experiments on public datasets corrupted
by different levels of Gaussian and Poisson noise support the effectiveness of
the proposed approaches against some state-of-the-art image denoising methods.
ARCNN achieved an overall average PSNR results of around 0.44dB and 0.96dB for
Gaussian and Poisson denoising, respectively FARCNN presented very consistent
results, even with slightly worsen performance compared to ARCNN.Comment: Published in: 2020 33rd SIBGRAPI Conference on Graphics, Patterns and
Images (SIBGRAPI
Jamming non-local quantum correlations
We present a possible scheme to tamper with non-local quantum correlations in
a way that is consistent with relativistic causality, but goes beyond quantum
mechanics. A non-local ``jamming" mechanism, operating within a certain
space-time window, would not violate relativistic causality and would not lead
to contradictory causal loops. The results presented in this Letter do not
depend on any model of how quantum correlations arise and apply to any jamming
mechanism.Comment: 10 pp, LaTe
High Resolution He-like Argon And Sulfur Spectra From The PSI ECRIT
We present new results on the X-ray spectroscopy of multicharged argon,
sulfur and chlorine obtained with the Electron Cyclotron Resonance Ion Trap
(ECRIT) in operation at the Paul Scherrer Institut (Villigen, Switzerland). We
used a Johann-type Bragg spectrometer with a spherically-bent crystal, with an
energy resolution of about 0.4 eV. The ECRIT itself is of a hybrid type, with a
superconducting split coil magnet, special iron inserts which provides the
mirror field, and a permanent magnetic hexapole. The high frequency was
provided by a 6.4 GHz microwave emitter. We obtained high intensity X-ray
spectra of multicharged F-like to He-like argon, sulfur and chlorine with one
1s hole. In particular, we observed the 1s2s^{3}S_1 \to 1s^2^{1}S_0 M1 and
1s2p^{3}P_2 \to 1s^2^{1}S_0 M2 transitions in He-like argon, sulfur and
chlorine with unprecedented statistics and resolution. The energies of the
observed lines are being determined with good accuracy using the He-like M1
line as a reference
Critical assessment of enhancement factor measurements in surface-enhanced raman scattering on different substrates
The SERS enhancement factor (SERS-EF) is one of the most important parameters that characterizes the ability of a given substrate to enhance the Raman signal for SERS applications. The comparison of SERS intensities and SERS-EF values across different substrates is a common practice to unravel the performance of a given substrate. In this study, it is shown that such a comparison may lack significance if we compare substrates of very distinct nature and optical properties. It is specifically shown that the SERS-EF values for static substrates (e.g. immobilized metallic nanostructures) cannot be compared to those of dynamic ones (e.g. colloidal metal nanoparticle solutions), and that the optical properties for the latter show strong dependence on the metal-molecule interaction dynamics. The most representative experimental results concerning the dynamic substrates have been supported by generalized Mie theory simulations, which are tools used to describe the substrate complexity and the microscopic information not usually taken into account17332129421301CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE MINAS GERAIS - FAPEMIGFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES
A new experiment for the determination of the 18F(p,alpha) reaction rate at nova temperatures
The 18F(p,alpha) reaction was recognized as one of the most important for
gamma ray astronomy in novae as it governs the early 511 keV emission. However,
its rate remains largely uncertain at nova temperatures. A direct measurement
of the cross section over the full range of nova energies is impossible because
of its vanishing value at low energy and of the short 18F lifetime. Therefore,
in order to better constrain this reaction rate, we have performed an indirect
experiment taking advantage of the availability of a high purity and intense
radioactive 18F beam at the Louvain La Neuve RIB facility. We present here the
first results of the data analysis and discuss the consequences.Comment: Contribution to the Classical Novae Explosions conference, Sitges,
Spain, 20-24 May 2002, 5 pages, 3 figure
Genome-wide analyses reveal a highly conserved Dengue virus envelope peptide which is critical for virus viability and antigenic in humans.
Targeting regions of proteins that show a high degree of structural conservation has been proposed as a method of developing immunotherapies and vaccines that may bypass the wide genetic variability of RNA viruses. Despite several attempts, a vaccine that protects evenly against the four circulating Dengue virus (DV) serotypes remains elusive. To find critical conserved amino acids in dengue viruses, 120 complete genomes of each serotype were selected at random and used to calculate conservation scores for nucleotide and amino acid sequences. The identified peptide sequences were analysed for their structural conservation and localisation using crystallographic data. The longest, surface exposed, highly conserved peptide of Envelope protein was found to correspond to amino acid residues 250 to 270. Mutation of this peptide in DV1 was lethal, since no replication of the mutant virus was detected in human cells. Antibodies against this peptide were detected in DV naturally infected patients indicating its potential antigenicity. Hence, this study has identified a highly conserved, critical peptide in DV that is a target of antibodies in infected humans
Fighting methicillin-resistant staphylococcus aureus with targeted nanoparticles
Antimicrobial resistance (AMR) is considered one of the greatest threats to global health. Methicillin-resistant Staphylococcus aureus (MRSA) remains at the core of this threat, accounting for about 90% of S. aureus infections widespread in the community and hospital settings. In recent years, the use of nanoparticles (NPs) has emerged as a promising strategy to treat MRSA infections. NPs can act directly as antibacterial agents via antibiotic-independent activity and/or serve as drug delivery systems (DDSs), releasing loaded antibiotics. Nonetheless, directing NPs to the infection site is fundamental for effective MRSA treatment so that highly concentrated therapeutic agents are delivered to the infection site while directly reducing the toxicity to healthy human cells. This leads to decreased AMR emergence and less disturbance of the individual’s healthy microbiota. Hence, this review compiles and discusses the scientific evidence related to targeted NPs developed for MRSA treatment.info:eu-repo/semantics/publishedVersio
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