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A rotaing black hole has interesting features which can't be seen in nonrotating cases. The most characteristic one is to induce differential rotaions at angular velocity ω in inertial frames. Astrophysically it might have various impacts on its surrounding accretion plasmas. In a stationary and axisymmetric magnetohydrodynamic picture, it enables to directly extract the rotation energy of the black hole in the form of the outgoing Poynting flux. This process needs a condition ΩF(ΩH – ΩF) > 0 on the horizon r = rH, where ΩH ≡ ω|rH, and ΩF is the angular velocity of magnetosphere. However, it is not so clear how the extracted energy activates the magnetosphere. Recently, Kahnna and Camenzind (KC 1994,1995) proposed a possibility of a self-excitation mechanism of the electromagnetic fields, supported by a coupling between ω and the angular velocity of plasma Ω, through the magnetic diffusivity e of accretion plasmas. They called it ωΩ dynamo and tried to confirm this effect by numerical simulations. However no such growing cases were found in the initial conditions employed in the simulations (Brandenbrug 1996, KC 1996).
In order to better understand the densification of polar firn, firn cores from the three sites within ~10 km of Dome Fuji, Antarctica, were investigated using surrogates of density: dielectric permittivities εv and εh at microwave frequencies with electrical fields in the vertical and horizontal planes respectively. Dielectric anisotropy Δε (=εv − εh) was then examined as a surrogate of the anisotropic geometry of firn. We find that layered densification is explained as a result of complex effects of two phenomena that commonly occur at the three sites. Basically, layers with initially smaller density and smaller geometrical anisotropy deform preferentially throughout the densification process due to textural effects. Second, layers having a higher concentration of Cl− ions deform preferentially during a limited period from the near surface depths until smoothing out of layered Cl− ions by diffusion. We hypothesize that Cl− ions dissociated from sea salts soften firn due to modulation of dislocation movement. Moreover, firn differs markedly across the three sites in terms of strength of geometrical anisotropy, mean rate of densification and density fluctuation. We hypothesize that these differences are caused by textural effects resulting from differences in depositional conditions within various spatial scales.
To control an input energy for a load, an impedance control with a gap distance of an electron beam diode was studied using an intense pulsed-power generator. The output current of the pulsed-power generator as a function of the gap distance of electron beam diode was measured. It indicated that the behaviors of the experimentally obtained peak current and the theoretically obtained space-charge limited current were found to decrease with an increase in the gap distance. The input energy for the load was estimated from the output current, which decreased with an increase in the gap distance. It also revealed the space-charge limited current suppresses the input energy for the load with a decade.
The 2011 Great East Japan Earthquake caused major disruptions in the provision of health care, including that for patients with sleep-disordered breathing (SDB) using a nasal continuous positive airway pressure (nCPAP) device. This study investigated the ability of SDB patients to continue using the nCPAP device in the weeks immediately following the earthquake, whether inability to use the nCPAP device led to symptom relapse, and measures that should be taken to prevent disruptions in nCPAP therapy during future disasters.
If nCPAP devices cannot be used during disasters, SDB patients’ health will be affected negatively.
Within 14 days of the disaster, 1,047 SDB patients completed a questionnaire that collected data regarding ability to use, duration of inability to use, and reasons for inability to use the nCPAP device; symptom relapse while unable to use the nCPAP device; ability to use the nCPAP device use at evacuation sites; and recommendations for improvement of the nCPAP device.
Of the 1,047 patients, 966 (92.3%) had been unable to use the nCPAP device in the days immediately following the earthquake. The most common reason for inability to use the nCPAP device was power failure, followed by anxiety about sleeping at night due to fear of aftershocks, involvement in disaster-relief activities, loss of the nasal CPAP device, and fear of being unable to wake up in case of an emergency. Among the 966 patients, 242 (25.1%) had experienced relapse of symptoms, the most common of which was excessive daytime sleepiness (EDS), followed by insomnia, headache, irritability, and chest pain.
Developing strategies for the continuation of nCPAP therapy during disasters is important for providing healthy sleeping environments for SDB patients in emergency situations.
MitoF, NishijimaT, SakuraiS, KizawaT, HosokawaK, TakahashiS, SuwabeA, AkasakaH, KobayashiS. Effects of CPAP Treatment Interruption Due to Disasters: Patients with Sleep-disordered Breathing in the Great East Japan Earthquake and Tsunami Area. Prehosp Disaster Med. 2013;28(6):547-555.
We have developed two types of devices for silicon-single-electronics; a single-electron transistor (SET) and a single-electron charge coupled device (CCD). Both devices were fabricated on SOI (silicon on insulator) wafers. For the SET fabrication, we used a novel method called pattern-dependent oxidation (PADOX), which exploits special phenomena that occur during thermal oxidation of a small silicon structure. The Si structures are converted into small Si SETs by consequence of stress-induced bandgap narrowing and quantum size effects. Since the size of the resultant Si island is about 10 nm, the SETs operate at relatively high temperatures. We have already developed several kinds of application of Si SETs by utilizing the special features of SETs. In addition, we have developed a single-electron CCD that enables us to manipulate a single electron without tunnel capacitors. The device utilizes small Si-wire MOSFETs connected in series, and an elementary charge can be transferred like in a CCD.
Wear properties of Li+, K+, C+, Cl+, and Ti+ implanted glassy carbons (GC) have been studied by wear tests using silicon carbide abrasive paper. It has been found that ion implantation is effective for improving wear resistance of GC. The measurements of Raman spectra revealed formation of an amorphous structure on the surface. Anomalous depth profiles with flat concentration distribution of Li and K atoms were observed by a secondary ion mass spectroscopy (SIMS). In conclusion. the formation of an amorphous structure seems to explain the improvement in wear resistance.
We prepared REBa2Cu3O7- δ (RE= Gd, Sm, Dy, Er, Y) coated conductors on pulsed laser deposition (PLD) -CeO2/ion-beam assisted deposition (IBAD) – Gd2Zr2O7 (GZO) / metal tapes by the PLD method and measured the characteristics in magnetic fields. The GdBa2Cu3O7- σ (Gd-123) films showed superior characteristics than others in magnetic fields and showed weak anisotropy. Critical current density (Jc) value of the Gd-123 film was 3.87MA/cm2 at self-field and 0.19MA/cm2 at 3 T of perpendicular field to the tape surface in liquid nitrogen (77 K). Angular dependences in magnetic fields (Jc -Θ) of the Gd-123 and the SmBa2Cu3O7- σ (Sm-123) were superior to others and peaks in Jc -Θ were found also at 0 degree. The reduction ratios of Jc in Jc -Θ for the Gd-123 film and the Sm-123 film were smaller than other films. Transmission electron microscopy showed that the Gd-123 film had many stacking faults. It may be considered that this stacking faults naturally introduced by the PLD method contribute to improvement of anisotropy of Jc -Θ in the Gd-123 film.
The magnetic characteristics of the dilute magnetic system GaGdN are investigated by mainly soft-X-ray magnetic circular dichroism (MCD) in energy range of 1160 – 1240 eV. The strong MCD signals up to 30 % at 15K are observed. The temperature dependence of its intensity is not on simple Curie-Weiss curve and depicts three-step curve. A step around 40 – 100K suggests a new magnetic phase. The luminescence spectrum of GaGdN at low temperature is divided into three parts consisting of two broad bands around 432 nm and 503 nm and a sharp peak at 652 nm. This sharp line is assigned to the intra-transition of f – f orbital owing to the weak temperature dependence of the intensity and peak position. AlGdN grown by molecular beam epitaxy produces luminescence at 318.5 nm. X-ray absorption fine structure is examined to survey the occupancy of the Gd ion in the grown specimens.
The single-electron device (SED), which has quantum dot(s), or island(s) in its core, enables the control of electron motion on the level of an elementary charge. The single-electron pump and turnstile are members of the SED family and enable single-electron transfer synchronized with the gate clock. They have the potential for extremely low error rates of electron transfer and are thus expected to be building-block devices for future information processing and electrical metrology. We have been pursuing the fabrication of Si-based SEDs using CMOS technology with the help of electron-beam lithography and have recently demonstrated a Si single-electron pump and turnstile. They are composed of one Si quantum dot and two tiny MOS gates and have dramatically increased the operation temperatures, which opens up the possibility of the practical use of the pump and turnstile.
Another path to realizing single-electron transfer, which we will discuss here, might be to use a localized state in the Si bandgap instead of quantum dots. The localized states could in principle be donor/acceptor levels or any other states created by crystalline imperfections. They are free from the problem of the critical size control of the quantum dots, which might lead to a new era of single-electronics in combination with the rapidly developing research field of “dopant engineering”.
We have investigated the thickness dependence of critical current for YBa2Cu3O7-x (YBCO) film with artificial pinning centers on metallic substrate. Artificial pinning centers were introduced by the pulsed laser deposition (PLD) using YBCO target including YSZ particles. The film over 1 μm in thickness exhibited with high critical current (Ic) of 40.7A in applied magnetic field of 3T parallel to the c-axis at 77K. This value was 5 times as high as the normal YBCO film without artificial pinning centers. The large Ic enabled us to approach to a practical application in the near future. Furthermore, it was clarified that the columnar nano-structure formed in the film, we call “the bamboo structure”, was a dominant pinning center because each Jc-θ curve of all thick films formed a universal line by the normalization of Jc. In addition, it was also found that YSZ addition has an optimal concentration for pinning by the study of YSZ concentration in the film.
The objective was to clarify the outcomes of cardiac surgery in trisomy 18 patients.
Patients and methods
We analysed 34 consecutive trisomy 18 patients, of whom 21 were males, with cardiac complications. They were divided into patients who underwent cardiac surgery and those who were conservatively treated. We compared rates of survival and discharge alive between two groups.
The surgery group included nine patients, with six males, who underwent cardiac surgery – intracardiac repair in three patients, pulmonary arterial banding in five patients, and ligation of the ductus in one patient – at median age of 2.2 months, ranging from 0.5 to 9.8, and with median weight of 2.6 kilograms, ranging from 1.5 to 3.2. Cardiac surgery and pre-operative assisted ventilation were hazardous factors leading to death. In the surgery group, cumulative survival rates at 1 month, 6 months, 12 months, and 24 months were 63%, 38%, 25%, and 22%, respectively, compared with 51%, 26%, 9%, and 9% in the conservative group. There was a significant difference (p = 0.002). The cumulative rates of discharge alive at 1 month, 3 months, and 6 months were 0%, 12%, and 65% in the surgery group, which did not differ from the conservative group (p = 0.80).
Cardiac surgery contributed to increased survival rate but not the rate of discharge alive in trisomy 18 patients. Cardiac surgery could not prevent all the trisomy 18 patients from death. The indication of cardiac surgery should be carefully individualised to improve the quality of life in trisomy 18 patients and concerned surrounding people.
Although most Kawasaki disease with giant coronary aneurysms is asymptomatic, conventional investigations might not identify previous lesions, or all Kawasaki disease with giant aneurysms at risk of future myocardial lesions. We evaluated the long-term histopathology of the myocardium, especially of intramural small vessels in asymptomatic Kawasaki disease with giant aneurysms.
The initial study comprised 16 consecutive Kawasaki patients – male-to-female ratio was 12:4 – aged from 2 to 12 years, and in the subsequent study, the same patients were aged from 4.9 to 16 years. Endomyocardial biopsies were histopathologically evaluated. Microangiopathies, mitochondrial abnormalities, and loss or disarray of myofibrils were compared by electron microscopy.
The incidence of histopathological abnormalities such as degeneration, hypertrophy, and inflammatory cell infiltration was quite high in the initial study, and inflammatory cell infiltration, interstitial fibrosis, and disarray were very noticeable at follow-up biopsies. The area of fibrous tissue was significantly higher in patients administered with intravenous immunoglobulin at follow-up biopsies. Electron microscopy showed microangiopathies including microthrombi within intramural small vessels in some patients at follow-up biopsies. The sites of the coronary aneurysms did not seem to have an impact on the biopsy findings, suggesting that the underlying pathophysiology is related to the original disease process.
Whether the abnormalities were due to direct myocardial injury, chronic ischaemia, repeated small-vessel thrombosis, or other problems associated only with biopsies, is difficult to determine. However, this subgroup had residual abnormal lesions in the myocardium. Follow-up should be more aggressive in this group of patients to identify myocardial damage that could be asymptomatic.
Three experiments were conducted to investigate the effect of dietary glycine (Gly) supplementation on inflammatory responses in broiler chicks fed a basal diet using maize and soyabean meal as the primary ingredients. Inflammation-related processes following lipopolysaccharide (LPS) injection were examined by analysing plasma concentrations of nitrate plus nitrite (NOx) and ceruloplasmin (Cer) in experiments 1 and 2, or expression of several genes in the spleen and liver including IL-1β and -6, TNF-like ligand (TL)1A, inducible NO synthase, interferon (IFN)-γ and toll-like receptor (TLR) 4 were examined in experiment 3. Growth performance was also determined following immunological stimulation by both LPS and Sephadex injection in experiment 2. In experiment 1, birds fed a diet supplemented with Gly at 10 or 20 g/kg showed lower responses in plasma NOx and Cer than birds fed the diet supplemented with Gly at 0 or 40 g/kg. In experiment 2, a similar effect of Gly supplementation at 10 g/kg on plasma NOx and Cer was observed when chicks were fed either an isonitrogenous diet with Gly or glutamic acid (Glu). Gly-supplemented diet-fed birds showed better growth performance than Glu-supplemented diet-fed birds. The splenic expression of inflammatory response-related genes in birds fed a diet supplemented with Gly at 10 g/kg diet was lower than that of birds fed the basal diet in experiment 3. These results suggest that dietary Gly supplementation modulates the inflammatory response partly through changes in the expression of pro-inflammatory cytokines such as IL-1, IL-6, IFN-γ and TL1A.
Binder-free macroscopic single-walled carbon nanotube (SWCNT) solids were prepared by spark plasma sintering (SPS) of purified SWCNTs. The effects of processing temperatures and pressures on the mechanical properties of the SWCNT solids and structural change of SWCNTs in the SWCNT solids were investigated. Transmission electron microscope observation of the SWCNT solids revealed thatthe high-temperature treatment has transformed some part of the SWCNTs into amorphous-like structure and the rest of the SWCNTs remained buried into the above structure. The mechanical properties of the SWCNT solids increased with the increasing processing temperature, probably reflecting the improvement of interfacial strength between SWCNTs and disordered structure of carbon due to the spark plasma generated in the SPS process.
Single-walled carbon nanotubes (SWCNTs) were successfully solidified without any additives by hot-pressing and spark plasma sintering (SPS). The elastic modulus and fracture strength of the SWCNT solid prepared by the SPS method were about three and two times higher than that of the hot-pressed SWCNT solid prepared under the same processing condition. The enhancement of the mechanical properties of the SPS specimen may be due to the formation of comparatively stronger bond between SWCNTs, which is possibly brought about by the spark plasma generated in the SPS process.
Background: Cardiac rhabdomyomas associated with tuberous sclerosis induce various abnormalities in the electrocardiogram. Electrocardiographic evidence of ventricular hypertrophy may appear if the tumour is electrically active. To our knowledge, electrocardiographic evidence of ventricular hypertrophy has been reported only in association with congestive heart failure. Follow-up studies of changes in electrocardiographic findings are also lacking. Methods: We studied 21 consecutive patients with cardiac rhabdomyoma associated with tuberous sclerosis, 10 males and 11 females, aged from the date of birth to 9 years at diagnosis. The mean period of follow-up was 53 months. None of the patients developed congestive heart failure. We evaluated the electrocardiographic changes during the follow-up, and their association with echocardiographic findings. Results: Of the 21 patients, 12 showed one or more abnormalities on the electrocardiogram at presentation, with five demonstrating right or left ventricular hypertrophy. In all of these five cases, the tumours were mainly located in the respective ventricular cavity. In one patient with a giant tumour expanding exteriorly, there was marked left ventricular hypertrophy on the electrocardiogram. Followup studies showed spontaneous regression of the tumours in 12 of 19 patients, with abnormalities still present in only 7 patients. A gradual disappearance of left ventricular hypertrophy as seen on the electrocardiogram was noted in the patient with marked left ventricular hypertrophy at presentation in parallel with regression of the tumour. Conclusions: The presence of cardiac rhabdomyomas in patients with tuberous sclerosis might explain the ventricular hypertrophy seen on the electrocardiogram through its electrically active tissue without ventricular pressure overload or ventricular enlargement, although pre-excitation might affect the amplitude of the QRS complex. Even in cases with large tumours, nonetheless, the electric potential might not alter the surface electrocardiogram if the direction of growth of the tumour is towards the ventricular cavity. In many cases, electrocardiographic abnormalities tend to disappear, concomitant with regression of the tumours.
Leg muscles were occluded (33 kPa) prior to exercise to determine whether the induced metabolic changes, and reactive hyperaemia upon occlusion release just prior to the exercise, would accelerate the subsequent oxygen consumption (V˙O2) response. Eight subjects performed double bouts (6 min duration, 6 min rest in-between) of square wave leg cycle ergometry both below and above their lactate threshold (LT). Prior to exercise, large blood pressure cuffs were put around the upper thighs. Occlusion durations were 0 min (control), 5 min and 10 min. Ischaemia was terminated within 5 s prior to exercise onset. Heart rate, V˙O2, ventilatory rate (V˙E), electromyogram (EMG) and haemoglobin/myoglobin (Hb/Mb) saturation were recorded continuously. Single exponential modelling demonstrated that, compared to control (time constant = 53.9 ± 13.9 s), ischaemia quickened the V˙O2 response (P < 0.05) for the first bout of exercise above LT (time constant = 48.3 ± 14.5 s) but not to any other exercise bout below or above LT. The 3-6 min integrated EMG (iEMG) slope was correlated to the 3-6 min V˙O2 slope (r = 0.73). Hb/Mb saturation verified the ischaemia but did not show a consistent relation to the V˙O2 time course. Reactive hyperaemia induced a faster V˙O2 response for work rates above LT. The effect, while significant, was not large considering the expected favourable metabolic and circulatory changes induced by ischaemia. Experimental Physiology (2002) 87.2, 227-235.