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In endoscopic cricopharyngeal myotomy, surgeons sometimes have concerns about performing an adequate incision with only a narrow intra-cavital view from one direction. In order to overcome these issues, fluoroscopic radiography was used during endoscopic cricopharyngeal myotomy.
Peri-operative fluoroscopic radiography was utilised to check the position of the diverticuloscope, and to confirm the extent of the incision during surgery. A balloon catheter was used to determine whether the cricopharyngeal muscle was sufficiently resected. Blood loss, peri-operative complications, and functional oral swallowing scale and penetration aspiration scale scores were evaluated.
In 12 out of 15 patients, intra-operative fluoroscopic radiography showed the diverticuloscope positioned in the post-cricoid area, and the cricopharyngeal muscle was raised and the surgery completed without adverse effect. Swallowing functions improved following surgery.
Intra-operative fluoroscopy might improve endoscopic cricopharyngeal myotomy by allowing surgeons to confirm the extent of resection, and by reducing peri-operative morbidity and complication rates.
Japan is still a medium-burden tuberculosis (TB) country. We aimed to examine trends in newly notified active TB incidence and TB-related mortality in the last two decades in Japan. This is a population-based study using Japanese Vital Statistics and Japan Tuberculosis Surveillance from 1997 to 2016. We determined active TB incidence and mortality rates (per 100 000 population) by sex, age and disease categories. Joinpoint regression was applied to calculate the annual percentage change (APC) in age-adjusted mortality rates and to identify the years showing significant trend changes. Crude and age-adjusted incidence rates reduced from 33.9 to 13.9 and 37.3 to 11.3 per 100 000 population, respectively. Also, crude and age-adjusted mortality rates reduced from 2.2 to 1.5 and 2.8 to 1.0 per 100 000 population, respectively. Average APC in the incidence and mortality rates showed significant decline both in men (−6.2% and −5.4%, respectively) and women (−5.7% and −4.6%, respectively). Age-specific analysis demonstrated decreases in incidence and mortality rates for every age category, except for the incidence trend in the younger population. Although trends in active TB incidence and mortality rates in Japan have favourably decreased, the rate of decline is far from achieving TB elimination by 2035.
The purpose of this study was to clarify the association between hand, foot, and mouth disease (HFMD) epidemics and meteorological conditions. We used HFMD surveillance data of all 47 prefectures in Japan from January 2000 to December 2015. Spectral analysis was performed using the maximum entropy method (MEM) for temperature-, relative humidity-, and total rainfall-dependent incidence data. Using MEM-estimated periods, long-term oscillatory trends were calculated using the least squares fitting (LSF) method. The temperature and relative humidity thresholds of HFMD data were estimated from the LSF curves. The average temperature data indicated a lower threshold at 12 °C and a higher threshold at 30 °C for risk of HFMD infection. Maximum and minimum temperature data indicated a lower threshold at 6 °C and a higher threshold at 35 °C, suggesting a need for HFMD control measures at temperatures between 6 and 35 °C. Based on our findings, we recommend the use of maximum and minimum temperatures rather than the average temperature, to estimate the temperature threshold of HFMD infections. The results obtained might aid in the prediction of epidemics and preparation for the effect of climatic changes on HFMD epidemiology.
We present recent observation results of Sgr A* at millimeter obtained with VLBI arrays in Korea and Japan.
7 mm monitoring of Sgr A* is part of our AGN large project. The results at 7 epochs during 2013-2014, including high resolution maps, flux density and two-dimensional size measurements are presented. The source shows no significant variation in flux and structure related to the G2 encounter in 2014. According to recent MHD simulations by kawashima et al., flux and magnetic field energy can be expected to increase several years after the encounter; We will keep our monitoring in order to test this prediction.
Astrometric observations of Sgr A* were performed in 2015 at 7 and 3.5 millimeter simultaneously. Source-frequency phase referencing was applied and a combined ”core-shift” of Sgr A* and a nearby calibrator was measured. Future observations and analysis are necessary to determine the core-shift in each source.
We have conducted 1.1 mm ALMA observations of a contiguous 105” × 50” or 1.5 arcmin2 window in the SXDF-UDS-CANDELS. We achieved a 5σ sensitivity of 0.28 mJy, giving a flat sensus of dusty star-forming galaxies with LIR ~6×1011L⊙ (if Tdust=40K) up to z ~ 10 thanks to the negative K-correction at this wavelength. We detected 5 brightest sources (S/N>6) and 18 low-significant sources (5>S/N>4; they may contain spurious detections, though). One of the 5 brightest ALMA sources (S1.1mm = 0.84 ± 0.09 mJy) is extremely faint in the WFC3 and VLT/HAWK-I images, demonstrating that a contiguous ALMA imaging survey uncovers a faint dust-obscured population invisible in the deep optical/near-infrared surveys. We find a possible [CII]-line emitter at z=5.955 or a low-z CO emitting galaxy within the field, allowing us to constrain the [CII] and/or CO luminosity functions across the history of the universe.
We present the discovery of out-flow like plasma emissions with the Suzaku and ASCA data. Those plasmas have a size of ∼150 pc. Remarkably, the southern plasma is in a recombination dominant phase, which is not predicted by standard shock heating. A plausible scenario is either photoionization due to strong jet-like X-rays from Sgr A* or rapid cooling due to adiabatic expansion of a blowout plasma from the Galactic center about 105 years ago.
We studied the electrical properties of thermally treated V2O5-CuO-Fe2O3-P2O5 (vanadate) glasses under reducing high-vacuum conditions. The glasses were prepared by using a melt-quenching method and then applied on Al2O3 substrates as ∼40μm-thick films. The glass films were then heat treated at 375−550°C under a vacuum of 10−6 Pa. Powder X-ray diffraction showed the formation of complex oxides of both MxV2O5 (M = Cu, Fe; x = 0.12−1.3) and vanadium oxides (VOx; x = 1.5−2.5). The resistivity of the glass film crystallized at 550°C measured at 50°C and 300°C were 1.8 × 100 Ωcm and 2.8 × 10−1 Ωcm, respectively, which was 10 times lower than that of the film crystallized in air. The Seebeck coefficient was −132 μV/K at 50°C and −130 μV/K at 300°C. These results show that the vanadate glasses crystallized under the appropriate condition become potential candidate materials for semiconductor and thermoelectric application.
Progress and challenges for chemical mechanical polishing (CMP) of GaN are discussed in detail by focusing on the importance of GaN surface oxidation during CMP. We report on the significant difference in the removal rates between Ga2O3 and GaN, suggesting that the surface oxidation reaction is the rate-limiting step for CMP of Ga-faced GaN. This is actually proved by the fact that ex-situ surface oxidation by annealing in air prior to CMP exhibits a marked reduction in the required CMP time to produce a damage-free surface. As a future challenge, we outline two of our recent developments, ultraviolet-assisted CMP and atmosphere-controlled CMP, that enable in-situ oxidation, since ex-situ oxidation must be modified to in-situ to further advance CMP.
We have investigated characteristic ferroelectric and structural antiphase domain structures in single crystals of hexagonal RMnO3 (R=Y, Ho, Lu, and Yb) by obtaining various electron diffraction patterns, dark-filed images and high-resolution lattice images. In the ferroelectric phase of RMnO3 characteristic domain structures consisting of six ferroelectric and structural antiphase domains, which can be identified as the “cloverleaf” pattern, is found in the (110) plane, in addition to the (001) plane, and are inherent to the ferroelectric phase of hexagonal RMnO3. In domain configuration with the cloverleaf pattern in the (110) plane, the structural antiphase boundaries are inclined to be parallel to the  direction.
Information about positions and velocities of stars that will be gained in the era of GAIA is crucial for determining dynamical structure in our Galaxy. The distribution function of all component objects in our Galaxy is fundamental for describing its dynamics. However, only the distribution function of observable stars is obtained from space astrometry observations, and it is therefore necessary to develop theoretical studies of how to construct the distribution function of all matter including dark matter and unobservable stars using astrometric data of observable stars. This procedure falls into three categories.
Future space mission of astrometric satellite, GAIA and JASMINE (Japan Astrometry Satellite Mission for Infrared Exploration), will produce astrometric parameter, such as positions, parallaxes, and proper motions of stars in the Galactic bulge. Then kinematical information will be obtained in the future. Accordingly it is expected that our understanding of the dynamical structure will be greatly improved. Therefore it is important to make a method to construct a kinematical and dynamical structure of the Galactic bulge immediately.
The propagation of intense laser pulses and the generation of high-energy electrons from underdense plasmas are investigated using two-dimensional particle-in-cell simulations. It is shown that quasi-monoenergetic electron beams are generated in the regime where the laser pulse length is much longer than the plasma wavelength, when the condition of the focusing is appropriately controlled.
Three-dimensional electron motion in a linearly polarized tightly focused laser field is numerically calculated. A high-intensity laser pulse focused on the free electrons in vacuum generates relativistic electron bunches whose length is shorter than the laser wavelength. The extremely short electron bunches with low-energy spread less than 1% are generated for a wide range of the laser parameters.
In 1984 an INTELSAT antenna of 32 m of diameter was constructed at 3 370 metres above the sea level on the Peruvian Andes. At the time Entel Perú the Peruvian tele-communications company managed the antenna station, of almost 12 hectares in extension. In 1993 the government transferred the station to the private telecommunications company Telefónica del Perú. Since transoceanic fiber optics replaced radically satellite communications in 2002, a beautiful 32- metre parabolic antenna was finished its tele-communications mission and become available for other use. So in cooperation with the National Astronomical Observatory of Japan we began coordination to transform the antenna into a radio-telescope.
Researches on interstellar medium around Young Stellar Objects (YSO) are possible using methanol maser that emits at 6.7 GHz, so initially we will monitor and survey maser sources at the southern sky. An ambient temperature receiver with Trx = 60 K was developed at Nobeyama Radio Observatory and is ready to be installed. The antenna will be controlled by the Field System FS9 software installed in a PC within a Linux environment. An interface between antenna and PC was developed at Kashima Space Research Center in Japan by Mr E. Vidal.
In the near future S-band (2 GHz), X-band (8GHz), 12 GHz and 22 GHz observations are planned.
The peculiar position and altitude of the Peruvian Radio Observatory will be useful for VLBI observations with the VLBA for astronomical observation and geodetic measurements. For Peru where few or almost non astronomical observational instruments are available for research, implementation of the first radio observatory is a big step to foster sciences at graduate and postgraduate levels of universities.
Worldwide tele-communications antennas recently tend to finish their role as tele-communications antennas. Several of them are transformed into useful observational instruments.
We have demonstrated the acceleration of a monoenergetic electron beam
by a laser-produced wakefield. Experiments were performed by focusing 2-TW
laser pulses of 50 fs on supersonic gas-jet targets. The focused intensity
was 5 × 1018 W/cm2 (a0
= 1.5). At an electron density of 1.5 × 1020
cm−3, the clear monoenergetic electron beam from the
plasma was obtained at 7 to 15 MeV. The Stokes satellite peak in the
forward scattering explained the energy spectra of electrons at various
plasma densities well. Although the wakefield propagated 500 microns,
which was far beyond the dephasing length, monoenergetic electron beams
In our previous investigations [1, 2], we have demonstrated that the introduction of fatigue pre-crack ahead of a notch is required to measure reliable fracture toughness values even for micro-sized specimens. However, it is rather difficult to introduce a fatigue pre-crack into a micro-sized specimen as once a fatigue crack starts to grow then the fatigue fracture occurs within one thousand cycles and this makes it extremely difficult to control fatigue crack length. Therefore, a new fatigue pre-cracking method is required for measuring fracture toughness. In this investigation, a new fatigue pre-cracking method has been proposed for micro-sized specimens and fracture toughness tests were carried out for the micro-sized specimens with fatigue pre-crack. Micro-cantilever beam type specimens with dimensions of 10 × 10 × 50 μm3 were prepared from an electroless deposited Ni-P amorphous alloy thin film and notches were introduced by focused ion beam machining. Fatigue pre-cracks were introduced ahead of the notches by far-field cyclic compression method using a mechanical testing machine for micro-sized specimens (MFT2000). Fracture tests were also carried out using the testing machine. Fatigue pre-cracks with length of 0.2 μm were confirmed on the fracture surfaces ahead of the notches in the far-field cyclically compressed specimens. This indicates that the fatigue pre-cracking method developed in this investigation is promising for measuring accurate fracture toughness for micro-sized specimens for MEMS applications.
The phase decomposition of the Al-rich γ TiAl intermetallic compound in the TiAl(L10) and Ti3Al5(P4/mbm) two phases region is investigated experimentally. On the phase decomposition of the Ti-56at%Al alloy, the single precipitate(Ti3Al5) shape is an oblate spheroid at the early stage of precipitation and each particle is aligned along certain direction of the orientation about 20 degrees from . During coarsening, the precipitates encounter each other, then, the shape of the particle becomes the slanted or bended plate. In the case of phase decomposition of the Ti-58at%Al alloy, the tweed-like structure is observed at the beginning of the aging. The precipitates are connected each other during coarsening, finally the microstructure becomes the large layered structure with a zigzag-shaped interface. These microstructure changes are simulated based on the phase field model. The morphology and the time development of the simulated microstructure are in good agreement with the experimental results.