35 research outputs found

    Behavioral therapy is superior to follow-up without intervention in patients with supragastric belching-A randomized study

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    Background Behavioral therapy (BT) has been proven effective in the treatment of supragastric belching (SGB) in open studies. The aim was to compare BT to follow-up without intervention in patients with SGB in a randomized study. Methods Forty-two patients were randomized to receive 5 sessions of BT, comprising diaphragmatic breathing exercises, or to follow-up without intervention. Patients were evaluated at 6 months, at which point the control group was also offered BT and evaluated after another 6 months. The frequency and intensity of belching and mental well-being were evaluated with a visual analog scale (VAS). Depression, anxiety, and health-related quality of life (HRQoL) were evaluated with four questionnaires: BDI, BAI, 15D, and RAND-36. Key results The frequency and intensity of SGB were significantly lower in the therapy group (n = 19) than in the control group (n = 18) at the 6-month control (p < 0.001). When all patients (n = 36) were evaluated 6 months after BT, in addition to relief in the frequency and intensity of belching (p < 0.001), mental well-being had also improved (p < 0.05). Of all 36 patients, 27(75%) responded to BT. Depression scores were lower after therapy (p < 0.05). Only minor changes occurred in anxiety and HRQoL. Conclusions and Inferences Behavioral therapy is superior to follow-up without intervention in patients with SGB in reducing belching and depression; it also improves mental well-being but has only a modest effect on anxiety and HRQoL.Peer reviewe

    Calibration of RADMON radiation monitor onboard Aalto-1 CubeSat

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    RADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the ΔE-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed.RADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the Delta E-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Effects of thermal vacuum nitridation of Si(100) surface via NH3 exposure

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    Low temperature treatments to control the Si-interface properties become more and more relevant to the broad Si-based electronics and photonics technology when the back-end-of-line processing is developed and the integration of hybrid materials on the Si platform increases. In this work we have investigated effects of NH3 nitridation of three different Si surfaces in ultrahigh-vacuum (UHV) chamber at 400 °C: (i) nitridation of well-defined Si(100) (2 × 1)+(1 × 2) cleaned by the high-temperature flash heating, (ii) nitridation of the Radio Corporation of America (RCA)-cleaned H-terminated Si(100) with the final HF dip, and (iii) nitridation of the RCA-treated (without the final HF dip) Si(100) which includes so-called wet-chemical oxide of SiO2. X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy/spectroscopy measurements show that nitrogen incorporates into subsurface layers of clean Si and into the SiO2 chemical-oxide layer, when the materials are exposed to NH3 background in UHV chamber without a plasma source at 400 °C or even at room temperature. XPS results indicate that the nitridation does not remove oxygen from the SiO2 chemical oxide. The nitridation of SiO2 is also found to increase the density of electron levels at 3 to 4 eV above the Fermi level. Electrical measurements of atomic-layer deposited HfO2/Si(100) capacitors with and without the nitridation support that the method has potential to decrease amount of interface defects and to control interface properties.​​​​​​​</ul

    Radiation monitor RADMON aboard Aalto-1 CubeSat : First results

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    The Radiation Monitor (RADMON) on-board Aalto-1 CubeSat is an energetic particle detector that fulfills the requirements of small size, low power consumption and low budget. Aalto-1 was launched on 23 June 2017 to a sun-synchronous polar orbit with 97.4° inclination and an average altitude of somewhat above 500 km. RADMON has been measuring integral particle intensities from October 2017 to May 2018 with electron energies starting at low-MeV and protons from 10 MeV upwards. In this paper, we present first electron and proton intensity maps obtained over the mission period. In addition, the response of RADMON measurements to magnetospheric dynamics are analyzed, and the electron observations are compared with corresponding measurements by the PROBA-V/EPT mission. Finally, we describe the RADMON data set, which is made publicly available.The Radiation Monitor (RADMON) on-board Aalto-1 CubeSat is an energetic particle detector that fulfills the requirements of small size, low power consumption and low budget. Aalto-1 was launched on 23 June 2017 to a sun-synchronous polar orbit with 97.4 degrees inclination and an average altitude of somewhat above 500 km. RADMON has been measuring integral particle intensities from October 2017 to May 2018 with electron energies starting at low-MeV and protons from 10 MeV upwards. In this paper, we present first electron and proton intensity maps obtained over the mission period. In addition, the response of RADMON measurements to magnetospheric dynamics are analyzed, and the electron observations are compared with corresponding measurements by the PROBA-V/EPT mission. Finally, we describe the RADMON data set, which is made publicly available. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Atomic-Scale Modification of Oxidation Phenomena on the Ge(100) Surface by Si Alloying

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    Properties of Ge oxides are significantly different from those of widely used Si oxides. For example, the instability of GeOx at device junctions causes electronic defect levels that degrade the performance of Ge-containing devices (e.g., transistors and infrared detectors). Therefore, the passivating Si layers have been commonly used at Ge interfaces to reduce the effects of Ge oxide instability and mimic the successful strategy of Si oxidation. To contribute to the atomic-scale knowledge and control of oxidation of such Si-alloyed Ge interfaces (O/Si/Ge), we present a synchrotron radiation core-level study of O/Si/Ge, which is combined with scanning probe microscopy measurements. The oxidation processes and electronic properties of O/Si/Ge(100) are examined as functions of Si amount and oxidation doses. In particular, the incorporation of Si into Ge is shown to cause the strengthening of Ge−O bonds and the increase of incorporated oxygen amount in oxide/Ge junctions, supporting that the method is useful to decrease the defect-level densities.</p

    Particle telescope aboard FORESAIL-1 : Simulated performance

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    The Particle Telescope (PATE) of FORESAIL-1 mission is described. FORESAIL-1 is a CubeSat mission to polar Low Earth Orbit. Its scientific objectives are to characterize electron precipitation from the radiation belts and to observe energetic neutral atoms (ENAs) originating from the Sun during the strongest solar flares. For that purpose, the 3-unit CubeSat carries a particle telescope that measures energetic electrons in the nominal energy range of 80–800 keV in seven energy channels and energetic protons at 0.3–10 MeV in ten channels. In addition, particles penetrating the whole telescope at higher energies will be measured in three channels: one >800 keV electron channel, two integral proton channels at >10 MeV energies. The instrument contains two telescopes at right angles to each other, one measuring along the spin axis of the spacecraft and one perpendicular to it. During a spin period (nominally 15 s), the rotating telescope will, thus, deliver angular distributions of protons and electrons, at 11.25-degree clock-angle resolution, which enables one to accurately determine the pitch-angle distribution and separate the trapped and precipitating particles. During the last part of the mission, the rotation axis will be accurately pointed toward the Sun, enabling the measurement of the energetic hydrogen from that direction. Using the geomagnetic field as a filter and comparing the rates observed by the two telescopes, the instrument can observe the solar ENA flux for events similar to the only one so far observed in December 2006. We present the Geant4-simulated energy and angular response functions of the telescope and assess its sensitivity showing that they are adequate to address the scientific objectives of the mission.The Particle Telescope (PATE) of FORESAIL-1 mission is described. FORESAIL-1 is a CubeSat mission to polar Low Earth Orbit. Its scientific objectives are to characterize electron precipitation from the radiation belts and to observe energetic neutral atoms (ENAs) originating from the Sun during the strongest solar flares. For that purpose, the 3-unit CubeSat carries a particle telescope that measures energetic electrons in the nominal energy range of 80-800 keV in seven energy channels and energetic protons at 0.3-10 MeV in ten channels. In addition, particles penetrating the whole telescope at higher energies will be measured in three channels: one >800 keV electron channel, two integral proton channels at >10 MeV energies. The instrument contains two telescopes at right angles to each other, one measuring along the spin axis of the spacecraft and one perpendicular to it. During a spin period (nominally 15 s), the rotating telescope will, thus, deliver angular distributions of protons and electrons, at 11.25-degree clock-angle resolution, which enables one to accurately determine the pitch-angle distribution and separate the trapped and precipitating particles. During the last part of the mission, the rotation axis will be accurately pointed toward the Sun, enabling the measurement of the energetic hydrogen from that direction. Using the geomagnetic field as a filter and comparing the rates observed by the two telescopes, the instrument can observe the solar ENA flux for events similar to the only one so far observed in December 2006. We present the Geant4-simulated energy and angular response functions of the telescope and assess its sensitivity showing that they are adequate to address the scientific objectives of the mission. (C) 2019 COSPAR. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    Observation of Si 2p Core‐Level Shift in Si/High‐κ Dielectric Interfaces Containing a Negative Charge

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    Negative static charge and induced internal electric field have often been observed in the interfaces between silicon and high‐κ dielectrics, for example Al2O3 and HfO2. The electric field provides either beneficial (e.g., field‐effect passivation) or harmful (e.g., voltage instability) effect depending on the application. Different intrinsic and extrinsic defects in the dielectric film and interface have been suggested to cause the static charge but this issue is still unresolved. Here spectroscopic evidence is presented for a structural change in the interfaces where static charge is present. The observed correlation between the Si core‐level shift and static negative charge reveals the role of Si bonding environment modification in the SiO2 phase. The result is in good agreement with recent theoretical models, which relate the static charge formation to interfacial atomic transformations together with the resulting acceptor doping of SiO2

    Decreasing Interface Defect Densities via Silicon Oxide Passivation at Temperatures Below 450 degrees C

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    Low-temperature (LT) passivation methods (700 degrees C). Therefore, the LT passivation of SiOx/Si has long been a research topic to improve application performance. Here, we demonstrate that an LT (<450 degrees C) ultrahigh-vacuum (UHV) treatment is a potential method that can be combined with current state-of-the-art processes in a scalable way, to decrease the defect densities at the SiOx/Si interfaces. The studied LT-UHV approach includes a combination of wet chemistry followed by UHV-based heating and preoxidation of silicon surfaces. The controlled oxidation during the LT-UHV treatment is found to provide an until now unreported crystalline Si oxide phase. This crystalline SiOx phase can explain the observed decrease in the defect density by half. Furthermore, the LT-UHV treatment can be applied in a complementary, post-treatment way to ready components to decrease electrical losses. The LT-UHV treatment has been found to decrease the detector leakage current by a factor of 2

    The Effect of Ultraviolet Treatment on TiO2 Nanotubes: A Study of Surface Characteristics, Bacterial Adhesion, and Gingival Fibroblast Response

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    Titanium dioxide (TiO2) nanotubes are emerging as a provocative target for oral implant research. The aim of this study was to evaluate the effect of UV on the wettability behavior, bacterial colonization, and fibroblast proliferation rate of TiO2 nanotube surfaces prepared using different anodization voltages and aimed for use as implant abutment materials. Four different experimental materials were prepared: (1) TiO2 nanotube 10 V; (2) TiO2 nanotube 15 V; (3) TiO2 nanotube 20 V; and (4) commercial pure titanium as a control group. TiO2 nanotube arrays were prepared in an aqueous electrolyte solution of hydrofluoric acid (HF, 0.5 vol.%). Different anodization voltages were used to modify the morphology of the TiO2 nanotubes. Equilibrium contact angles were measured using the sessile drop method with a contact angle meter. The investigated surfaces (n = 3) were incubated at 37 degrees C in a suspension of Streptococcus mutans (S. mutans) for 30 min for bacterial adhesion and 3 days for biofilm formation. Human gingival fibroblasts were plated and cultured on the experimental substrates for up to 7 days and the cell proliferation rate was assessed using the AlamarBlue assay(TM) (BioSource International, Camarillo, CA, USA). The data were analyzed using one-way ANOVA followed by Tukey's post-hoc test. Water contact angle measurements on the TiO2 after UV treatment showed an overall hydrophilic behavior regardless of the anodization voltage. The ranking of the UV-treated surfaces of experimental groups from lowest to highest for bacterial adhesion was: TiO2 nanotube 20 V < Ti and TiO2 nanotube 15 V < TiO2 nanotube 10 V (p < 0.05), and for bacterial biofilm formation was: TiO2 nanotube 20 V-TiO2 nanotube 10 V < Ti-TiO2 nanotube 15 V (p < 0.05). Fibroblast cell proliferation was lower on TiO2 nanotube surfaces throughout the incubation period and UV light treatment showed no enhancement in cellular response. UV treatment enhances the wettability behavior of TiO2 nanotube surfaces and could result in lower bacterial adhesion and biofilm formation
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