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Suguru Sato, Junpei Saito, Atsuro Fukuhara, Manabu Uematsu, Yasuhito Suzuki, Mami Rikimaru, Takaya Kawamata, Takashi Umeda, Tatsuhiko Koizumi, Ryuichi Togawa, Yuki Sato, Takefumi Nikaido, Hiroyuki Minemura, Kenya Kanazawa, Yoshinori Tanino, Yoko Shibata Department of Pulmonary Medicine, School of Medicine, Fukushima Medical University, Fukushima, 960-1295, JapanCorrespondence: Suguru SatoDepartment of Pulmonary Medicine, School of Medicine, Fukushima Medical University, Hikarigaoka-1, Fukushima, 960-1295, JapanTel +81-24-547-1360Fax +81-24-548-9366Email suguru@fmu.ac.jpBackground: Nocturnal asthma symptoms are a well-known feature of sleep disturbance. However, there are few reports on the association between sleep-related characteristics and asthma exacerbation. The aim of the current prospective observational study was to explore the factors while sleeping associated with future asthma exacerbation.Materials and Methods: At baseline, adult asthmatics underwent home sleep monitoring by a Watch-PAT instrument and then they were prospectively followed-up for the occurrence of exacerbations. The number of asthma exacerbation was observed over a period of one year, and multivariable analyses of the factors associated with asthma exacerbation were performed.Results: A total of 62 asthmatic subjects were enrolled (mean age 62.1 years), 59 of whom were finally included in the prospective observational study. Obstructive sleep apnea (defined by an apnea-hypopnea index based on peripheral arterial tone more than 5 times/hour) were observed in 81% of the subjects. During the one-year monitoring period, 14 of the 59 subjects (24%) used occasional systemic corticosteroids for their exacerbation asthma (worsened group) while the other 45 subjects did not experience asthma exacerbation (stable group). A comparison of the baseline clinical characteristics and sleep-related data between the two groups, mean forced expiratory volume one second percent (FEV1/FVC), mean baseline Asthma Control Test (ACT) score, median pAHI value, and median oxygen desaturation index value were significantly lower in the worsened group than those in the stable group. Additionally, mean prevalence of the left lateral decubitus (LLD) position in sleep monitoring were significantly higher in the worsened group than that in the stable group. Among the independent variables, baseline asthma severity, ACT score, and the LLD position showed significant associations with asthma exacerbation.Discussion/Conclusion: The present study identified that sleeping in the LLD position was also associated with asthma exacerbation.Keywords: asthma, asthma control, sleep position, asthma exacerbation

We characterized an intrinsic interface defect, called the "PbC center," formed at 4H-SiC(0001)/SiO2 interfaces by means of electron-spin-resonance (ESR) and electrically detected-magnetic-resonance (EDMR) spectroscopies. The formation of the PbC center was observed with a spin density of 3–4 × 1012 cm−2 after standard thermal oxidation. This center could be effectively removed by the NO post-oxidation-anneal (POA) process or ultra-high-temperature oxidation and could be passivated by H atoms via the H2 POA process. There was a clear correlation between the PbC center and field-effect mobility (μFE) of 4H-SiC(0001) metal–oxide–semiconductor field effect transistors (MOSFETs). The PbC center decreased μFE because this center acts as electron traps, reducing the free-carrier density in the inversion channel of 4H-SiC(0001) MOSFET. We also examined the counter doping effect of NO POA by introducing 15N impurities; however, the counter doping of 15N donors was not detectable by ESR (much lower than 2 × 1011 cm−2). Highly sensitive EDMR measurements revealed that the PbC center has two isotropic hyperfine (HF) interactions at 1.3 and 6.8 mT and suggested that its main 13C HF interaction should be larger than 14 mT. Based on the present experimental data, the origin of the PbC center was ascribed as a carbon-related interface defect that forms a C–H bond after hydrogen passivation. This feature is similar to that of the porous-PbC centers (carbon dangling-bond centers) found in porous-SiC/SiO2 systems. However, their HF signatures indicated that the PbC center at 4H-SiC(0001)/SiO2 interfaces and the porous-PbC centers in porous-SiC should be different centers associated with different wave functions. [ABSTRACT FROM AUTHOR]

We investigated a metal-oxide-semiconductor interface of dry-oxidized (000 1 ¯ ) 4H-SiC, which was known as the most electrically deteriorated SiC MOSFET, by electrically detected magnetic resonance (EDMR) and observed a signal with an isotropic g factor (2.0024) and magnetic-field angular dependent signal widths. Judging from the g factor, the signal comes from sp2-bonded carbon clusters. In addition, we found that the angular dependence of EDMR signal widths was caused by two-dimensional dipolar broadening with exchange interaction between electron spins. However, the density of electron spins or carbon clusters was 5.4 × 1013 cm−2, which was not high enough for exchange interaction. Therefore, we propose inhomogeneous distribution of carbon clusters in the interface. At the interface, π* peaks from sp2-bonded carbon atoms were detected by electron energy loss spectroscopy. Scanning the electron beams along the interface revealed uneven existence of the π* peaks, which also proved that the sp2-bonded carbon atoms were distributed inhomogeneously in the interface. In addition, we found the formation of sp2-bonded carbon clusters at 4H-SiC(000 1 ¯ )/SiO2 interfaces and interaction between π-conjugate electron spins on the carbon clusters by first principles calculation. Such carbon clusters generated electrically active states widely in the energy gap of 4H-SiC. The states result in the Fermi level pinning of the MOSFET. [ABSTRACT FROM AUTHOR]

Magnetic reconnection is a key fundamental process in collisionless plasmas, which converts magnetic energy to plasma kinetic energy. Past observation and simulation studies suggested that this process causes an efficient energy conversion through the formation and coalescence of multiple magnetic islands. In this study, based on a large-scale two-dimensional fully kinetic simulations of coalescing multiple islands with a moderate guide magnetic field, we first examined the spatial dimensions of the internal structures of the coalescing islands. The results show that the dimensions of the structures in the directions normal to and along the initial current sheet depend on the initial thickness of the current sheet and the number of coalescing islands. We then found that the horizontal dimension of the structures controls the evolution time scale of the island coalescence process. We further found that when the vertical dimension of the structures, which corresponds to the length of the reconnection X-line in the reconnection outflow direction at the merging point between the two coalescing islands, is sufficiently longer than the ion inertial length, reconnection in the merging current sheet can well mature and both ions and electrons can be effectively heated around the merging X-line. The obtained scaling predicts that such a strong heating by well-matured reconnection in the island coalescence process would be seen in various plasma environments, such as the Earth's magnetotail and solar flares. [ABSTRACT FROM AUTHOR]

Electrically detected magnetic resonance is used to study the microscopic structure of ion-implantation-inducted point defects that remained in large-scale Si integrated circuits (Si LSIs). The study after examining the relationship between the defects and current-voltage characteristics concludes that these defects are distributed in the near-surface n(super +) - type region close to the gate and that they are the source of the gate-induced drain leakage currents.

At the Earth's low-latitude magnetopause, the Kelvin–Helmholtz instability (KHI), driven by the velocity shear between the magnetosheath and magnetosphere, has been frequently observed during northward interplanetary magnetic field (IMF) periods. However, the signatures of the KHI have been much less frequently observed during southward IMF periods, and how the KHI develops under southward IMF has been less explored. Here, we performed a series of realistic 2D and 3D fully kinetic simulations of a KH wave event observed by the Magnetospheric Multiscale (MMS) mission at the dusk-flank magnetopause during southward IMF on September 23, 2017. The simulations demonstrate that the primary KHI bends the magnetopause current layer and excites the Rayleigh–Taylor instability (RTI), leading to penetration of high-density arms into the magnetospheric side. This arm penetration disturbs the structures of the vortex layer and produces intermittent and irregular variations of the surface waves which significantly reduces the observational probability of the periodic KH waves. The simulations further demonstrate that in the non-linear growth phase of the primary KHI, the lower-hybrid drift instability (LHDI) is induced near the edge of the primary vortices and contributes to an efficient plasma mixing across the magnetopause. The signatures of the large-scale surface waves by the KHI/RTI and the small-scale fluctuations by the LHDI are reasonably consistent with the MMS observations. These results indicate that the multi-scale evolution of the magnetopause KH waves and the resulting plasma transport and mixing as seen in the simulations may occur during southward IMF. [ABSTRACT FROM AUTHOR]

Large area (63.6 mm x 64 mm) n-on-n silicon strip detectors have been fabricated, implementing various p-stop structures in the n-side. The detectors were characterized in laboratory and in beamtests. The beamtests showed that the individual p-stop structure collected less charge in the region between the strips than other p-stop structures.