Contact interactions of a muon, an electron and two photons can contribute to the decay μ → eγγ, but also to the conversion of a muon into an electron in the electric field of a nucleus. We calculate ...the μ → e conversion rate, and show that for the coefficients of operators involving the combination FF ∝ |→E|2 (as opposed to F˜F ∝ →E⋅ →B), the current bound on μ → e conversion is more sensitive than the bound on μ → eγγ.
The present study assessed the inhibitory action of exopolysaccharides (EPS) produced by Lactobacillus delbrueckii ssp. bulgaricus OLL1073R‐1 against influenza virus infection followed by secondary ...bacterial infection. We found that the presence of 200 or 400 μg ml−1 of EPS significantly protected against influenza virus infection in a dose‐dependent manner when A549 cells were treated with EPS before infection but not after it. The expression of carcinoembryonic antigen‐related cell adhesion molecule 1 (CEACAM‐1), an adhesion molecule for bacteria adherence, on A549 cells was significantly enhanced during influenza virus infection compared with viral‐non‐infected A549 cells. However, this upregulated CEACAM‐1 expression was significantly decreased by EPS treatment before viral infection in association with the reduction in the virus titre in A549 cells. In a bacterial adhesion assay using Staphylococcus aureus, the bacterial adherence to viral‐infected A549 cells was significantly greater than that to viral‐non‐infected A549 cells, and the increased bacterial adherence induced by influenza virus infection tended to be decreased by EPS treatment before the infection. Our findings show that EPS treatment before viral infection can inhibit influenza virus infection and alleviate secondary bacterial infection through decreased CEACAM‐1 expression.
Significance and Impact of the Study: This study demonstrated that exopolysaccharides (EPS) derived from Lactobacillus delbrueckii ssp. bulgaricus OLL1073R‐1 prevent influenza virus infection to A549 cells in vitro. Moreover, the EPS reduced upregulated expression of CEACAM‐1 (an adhesion molecule for bacterial adherence) on A549 cells resulting in reducing the bacterial adhesion to viral‐infected cells. This attenuates the risk of secondary bacterial infection.
In ageing societies, it is necessary to make the visual environment more appropriate for the elderly so that they can maintain visual performance as long as possible. To this end, we aimed at ...developing guidelines to determine appropriate adaptation luminance and luminance contrast for given letter sizes for the elderly. In this study, we first measured the contrast sensitivities of older participants. Second, we conducted an experiment in which the same participants evaluated the degrees of readability of Japanese sentences with various letter sizes, luminance contrasts and adaptation luminances. Based on the evaluations, we developed a readability model consisting of equal-readability-level contour lines that represent the average of older peoples’ readability scores. From the model, we found we could improve readability by increasing adaptation luminance while the adaptation luminance was lower than 200 cd/m2. However, an increase in luminance contrast became more helpful to improve readability than an increase in adaptation luminance when the adaptation luminance was higher than 200 cd/m2. We also found large individual deviations in readability evaluation among older participants depending on the contrast sensitivity. We divided the participants into three groups based on their contrast sensitivity levels and compared readability models among the three groups.
COMET (Coherent Muon to Electron Transition, J-PARC, Japan) is one of the experiments that studies extensions of the Standard Model (SM) of elementary particle physics. The main purpose of the COMET ...experiment is to search for charged lepton flavor violating neutrinoless conversion of muons into electrons in the field of a nucleus (μ–e conversion, μ–N → e–N). The goal is to achieve a sensitivity to the branching ratio superior to 10−17, that four orders of magnitude smaller than the present limit. In the experiment a straw detector will be used to measure the momentum of the signal electrons from the μ–e conversion. In order to satisfy the requirements of the momentum measurements, we plan to develop a planar tracking device consisting of thin-wall straws made with an extremely light material to reduce multiple scattering and that is capable of operation in vacuum. Research the mechanical properties of straws will allow us to choose their optimal tension, to estimate the influence of the temperature and humidity, to assess the straws service life in the experiment, which we define as the tension relaxation time to the minimum working value.
Test of a small prototype of the COMET cylindrical drift chamber Wu, C.; Wong, T.S.; Kuno, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2021, Letnik:
1015
Journal Article
Recenzirano
Odprti dostop
The performance of a small prototype of a cylindrical drift chamber (CDC) used in the COMET Phase-I experiment was studied by using an electron beam. The prototype chamber was constructed with ...alternating all-stereo wire configuration and operated with the He−iC4H10(90/10) gas mixture without a magnetic field. The drift space–time relation, drift velocity, dE/dx resolution, hit efficiency, and spatial resolution as a function of distance from the wire were investigated. The average spatial resolution of 150 μm with the hit efficiency of 99% was obtained at applied voltages higher than 1800V. We have demonstrated that the design and gas mixture of the prototype match the operation of the COMET CDC.
A new muon beam line, the muon science innovative channel, was set up at the Research Center for Nuclear Physics, Osaka University, in Osaka, Japan, using the 392 MeV proton beam impinging on a ...target. The production of an intense muon beam relies on the efficient capture of pions, which subsequently decay to muons, using a novel superconducting solenoid magnet system. After the pion-capture solenoid, the first 36° of the curved muon transport line was commissioned and the muon flux was measured. In order to detect muons, a target of either copper or magnesium was placed to stop muons at the end of the muon beam line. Two stations of plastic scintillators located upstream and downstream from the muon target were used to reconstruct the decay spectrum of muons. In a complementary method to detect negatively charged muons, the x-ray spectrum yielded by muonic atoms in the target was measured in a germanium detector. Measurements, at a proton beam current of 6 pA, yielded (10.4±2.7)×105muons per watt of proton beam power (μ+ and μ− ), far in excess of other facilities. At full beam power (400 W), this implies a rate of muons of (4.2±1.1)×108muonss−1 , among the highest in the world. The number of μ− measured was about a factor of 10 lower, again by far the most efficient muon beam produced. The setup is a prototype for future experiments requiring a high-intensity muon beam, such as a muon collider or neutrino factory, or the search for rare muon decays which would be a signature for phenomena beyond the Standard Model of particle physics. Such a muon beam can also be used in other branches of physics, nuclear and condensed matter, as well as other areas of scientific research.
Summary The objective of this study was to explore independent risk factors for the isolation of multidrug-resistant (MDR) Pseudomonas aeruginosa in a Japanese university hospital between January ...1997 and December 2010. MDR P. aeruginosa was defined when the organism was resistant or intermediately susceptible to all five antimicrobials tested. In all, 159 patients with MDR P. aeruginosa were identified over the 14-year period. Multivariate logistic regression analysis revealed that prolonged hospital stay, prior exposure to meropenem and fluoroquinolones, and patients suffering from diabetes mellitus or receiving surgery were predictive risk factors for the isolation of MDR P. aeruginosa.
The purpose of this study was to compare the muscle architectural characteristics, i. e., muscle thickness, pennation angle, fascicle length, of four different groups comprising a total of 121 men ...and 190 women, divided according to sex and age (i. e., 20 - 39 yrs and 60 - 85 yrs). Muscle thickness and pennation angles of the vastus lateralis (VL), medial gastrocnemius (MG), long head of triceps brachii (TB) muscles were measured by B-mode ultrasonography, and fascicle length was estimated. Men had significantly greater relative muscle thickness (to limb length) than women, but not for MG. Relative muscle thickness of VL was significantly greater in younger subjects than in elderly (men; p < 0.001, women; p < 0.001), although there were no significant differences in relative muscle thickness of MG and TB between younger and elderly subjects. Men had significantly greater pennation angles than women, but not for MG in elderly subjects. The pennation angle of VL was significantly greater in younger subjects than in elderly (men; p < 0.001, women; p < 0.001), although there were no significant differences in pennation angles of MG and TB between younger and elderly subjects. Women had longer relative fascicle lengths (to limb length) of VL than men (p = 0.048 for younger, p = 0.028 for elderly). These results suggest that the decrease of thickness of the vastus lateralis muscle with aging is significant, and that there is the gender difference in the fascicle length of the vastus lateralis muscle.
ABSTRACT
Vaccination of poultry is one promising strategy to mitigate Salmonella infection in poultry and, in turn, humans as well. We evaluated the efficacy of outer membrane protein A (OmpA) as a ...novel vaccine candidate against Salmonella in poultry. Native OmpA purified from Salmonella enterica serovar Enteritidis was mixed with adjuvant and administered intramuscularly to 41-d-old chicks. The vaccinated birds showed no decrease in cecal excretion and tissue colonization compared with the unvaccinated birds after oral challenge with 109 cfu of the homologous strain at 28 d postimmunization. However, this vaccination induced an increased level of serum anti-OmpA IgG. Similar results were obtained in the replication experiments using a recombinant OmpA with single and double doses. For the development of more effective component vaccines for avian salmonellosis, the vaccine efficacy of outer membrane proteins other than OmpA and route of immunization other than parenteral administration should be evaluated with regard to protection and immune responses, including mucosal IgA.
Rare lepton decays Kuno, Y.
Progress in particle and nuclear physics,
05/2015, Letnik:
82
Journal Article
Recenzirano
This article describes rare lepton decays, in particular, the rare processes in which lepton flavor of charged leptons is not conserved. Physics motivation, phenomenology, current experimental status ...and their future prospects for rare lepton decays are presented.
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