48 research outputs found
Identifying Suspicious Regions of Covid-19 by Abnormality-Sensitive Activation Mapping
This paper presents a fully-automated method for the identification of
suspicious regions of a coronavirus disease (COVID-19) on chest CT volumes. One
major role of chest CT scanning in COVID-19 diagnoses is identification of an
inflammation particular to the disease. This task is generally performed by
radiologists through an interpretation of the CT volumes, however, because of
the heavy workload, an automatic analysis method using a computer is desired.
Most computer-aided diagnosis studies have addressed only a portion of the
elements necessary for the identification. In this work, we realize the
identification method through a classification task by using a 2.5-dimensional
CNN with three-dimensional attention mechanisms. We visualize the suspicious
regions by applying a backpropagation based on positive gradients to
attention-weighted features. We perform experiments on an in-house dataset and
two public datasets to reveal the generalization ability of the proposed
method. The proposed architecture achieved AUCs of over 0.900 for all the
datasets, and mean sensitivity and specificity . The method can also identify notable lesions pointed out in the
radiology report as suspicious regions.Comment: 10 pages, 3 figure
The New Minimal Supersymmetric GUT : Spectra, RG analysis and Fermion Fits
The supersymmetric SO(10) GUT based on the Higgs system provides a minimal framework for the
emergence of the R-parity exact MSSM at low energies and a viable
supersymmetric seesaw explanation for the observed neutrino masses and mixing
angles. We present formulae for MSSM decomposition of the superpotential
invariants, tree level light charged fermion effective Yukawa couplings,
Weinberg neutrino mass generation operator, and the effective superpotential in terms of GUT parameters. We use them to
determine fits of the 18 available fermion mass-mixing data in terms of the
superpotential parameters of the NMSGUT and SUGRY(NUHM) type soft supersymmetry
breaking parameters () specified
at the MSSM one loop unification scale GeV. Our fits are
compatible with electroweak symmetry breaking and Unification constraints and
yield right-handed neutrino masses in the leptogenesis relevant range :
GeV. Matching the SM data requires lowering the strange and
down quark Yukawas in the MSSM via large driven threshold
corrections and characteristic soft Susy breaking spectra. The Susy spectra
have light pure Bino LSP, heavy exotic Higgs(inos) and large parameters TeV. Typically third generation
sfermions are much \emph{heavier} than the first two generations. The smuon is
often the lightest charged sfermion thus offering a Bino-CDM co-annihilation
channel. The parameter sets obtained are used to calculate B violation rates
which are found to be generically much faster() than
the current experimental limits. Improvements which may allow acceptable B
violation rates are identified.Comment: Latex2e, 45 pages, 4 Appendices, 14 Tables. This is the final merged
version of hep-ph/0612021 AND 0807.0917 and is identical with the version to
be published in Nuclear Physics B. The fits have been updated in the light of
LHC 1Fb^-1 data. Calculational details and plots omitted in this published
version can be found in the previous arXiv version
Virological characteristics of the SARS-CoV-2 Omicron BA.2.75 variant
SARS-CoV-2オミクロンBA.2.75株(通称ケンタウロス)のウイルス学的性状の解明. 京都大学プレスリリース. 2022-10-12.The SARS-CoV-2 Omicron BA.2.75 variant emerged in May 2022. BA.2.75 is a BA.2 descendant but is phylogenetically distinct from BA.5, the currently predominant BA.2 descendant. Here, we show that BA.2.75 has a greater effective reproduction number and different immunogenicity profile than BA.5. We determined the sensitivity of BA.2.75 to vaccinee and convalescent sera as well as a panel of clinically available antiviral drugs and antibodies. Antiviral drugs largely retained potency but antibody sensitivity varied depending on several key BA.2.75-specific substitutions. The BA.2.75 spike exhibited a profoundly higher affinity for its human receptor, ACE2. Additionally, the fusogenicity, growth efficiency in human alveolar epithelial cells, and intrinsic pathogenicity in hamsters of BA.2.75 were greater than those of BA.2. Our multilevel investigations suggest that BA.2.75 acquired virological properties independent of BA.5, and the potential risk of BA.2.75 to global health is greater than that of BA.5
Convergent evolution of SARS-CoV-2 Omicron subvariants leading to the emergence of BQ.1.1 variant
In late 2022, various Omicron subvariants emerged and cocirculated worldwide. These variants convergently acquired amino acid substitutions at critical residues in the spike protein, including residues R346, K444, L452, N460, and F486. Here, we characterize the convergent evolution of Omicron subvariants and the properties of one recent lineage of concern, BQ.1.1. Our phylogenetic analysis suggests that these five substitutions are recurrently acquired, particularly in younger Omicron lineages. Epidemic dynamics modelling suggests that the five substitutions increase viral fitness, and a large proportion of the fitness variation within Omicron lineages can be explained by these substitutions. Compared to BA.5, BQ.1.1 evades breakthrough BA.2 and BA.5 infection sera more efficiently, as demonstrated by neutralization assays. The pathogenicity of BQ.1.1 in hamsters is lower than that of BA.5. Our multiscale investigations illuminate the evolutionary rules governing the convergent evolution for known Omicron lineages as of 2022
Soot particle behavior in a flame by propane gas mixed with wood powder(MARITIE STUDIES, AND SCIENCE AND ENGINEERING)
One Step Preparation of Fe–FeO–Graphene Nanocomposite through Pulsed Wire Discharge
The Fe–FeO–graphene nanocomposite material was produced successfully by pulsed wire discharge in graphene oxide (GO) suspension. Pure iron wires with a diameter of 0.25 mm and a length of 100 mm were used in the experiments. The discharge current and voltage were recorded to analyze the process of the pulsed wire discharge. The as-prepared samples—under different charging voltages—were recovered and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and transmission electron microscopy (TEM). Curved and loose graphene films that were anchored with spherical Fe and FeO nanoparticles were obtained at the charging voltage of 8–10 kV. The present study discusses the mechanism by which the Fe–FeO–graphene nanocomposite material was formed during the pulsed wire discharge process
MARITIE STUDIES, AND SCIENCE AND ENGINEERING
The world energy resource mainly depends on the fossil fuel, but it will be used up in tens of years. On the way to search renewable and environment-friendly energy resource, the biomass has been utilized for many years, but the corresponding problems including the thermal efficiency and pollution need to be resolved. At the present time, LPG (major components are propane and butane) has a great potential to be utilized and with less exhaust pollutants. This paper focuses on applying the propane gas and wood powder to form mixed fuel flame. As a fundamental research, two experiments are carried out to investigate the soot particle behaviors. One is the soot particle diameter measurement by Gmie's light scattering theory, the results show that the soot particle diameter of the mixed fuel flame is greater than that of the propane gas flame. Another is the soot particle density measurement by weight difference method. The results show that the soot particle density of the mixed fuel flame is greater than that of the propane gas flame. The experiments make clear that the wood powder can be applied to form a mixed fuel flame with propane gas