Abstract
Achieving high mobility in SnO
2
, which is a typical wide gap oxide semiconductor, has been pursued extensively for device applications such as field effect transistors, gas sensors, and ...transparent electrodes. In this study, we investigated the transport properties of lightly Ta-doped SnO
2
(Sn
1−
x
Ta
x
O
2
, TTO) thin films epitaxially grown on TiO
2
(001) substrates by pulsed laser deposition. The carrier density (
n
e
) of the TTO films was systematically controlled by
x
. Optimized TTO (
x
= 3 × 10
−3
) films with
n
e
~ 1 × 10
20
cm
−3
exhibited a very high Hall mobility (
μ
H
) of 130 cm
2
V
−1
s
−1
at room temperature, which is the highest among SnO
2
films thus far reported. The
μ
H
value coincided well with the intrinsic limit of
μ
H
calculated on the assumption that only phonon and ionized impurities contribute to the carrier scattering. The suppressed grain-boundary scattering might be explained by the reduced density of the {101} crystallographic shear planes.
An upgraded version of the Particle and Heavy Ion Transport code System, PHITS2.52, was developed and released to the public. The new version has been greatly improved from the previously released ...version, PHITS2.24, in terms of not only the code itself but also the contents of its package, such as the attached data libraries. In the new version, a higher accuracy of simulation was achieved by implementing several latest nuclear reaction models. The reliability of the simulation was improved by modifying both the algorithms for the electron-, positron-, and photon-transport simulations and the procedure for calculating the statistical uncertainties of the tally results. Estimation of the time evolution of radioactivity became feasible by incorporating the activation calculation program DCHAIN-SP into the new package. The efficiency of the simulation was also improved as a result of the implementation of shared-memory parallelization and the optimization of several time-consuming algorithms. Furthermore, a number of new user-support tools and functions that help users to intuitively and effectively perform PHITS simulations were developed and incorporated. Due to these improvements, PHITS is now a more powerful tool for particle transport simulation applicable to various research and development fields, such as nuclear technology, accelerator design, medical physics, and cosmic-ray research.
Galactosemia is caused by metabolic disturbances at various stages of galactose metabolism, including deficiencies in enzymes involved in the Leloir pathway (GALT, GALK1, and GALE). Nevertheless, the ...etiology of galactosemia has not been identified in a subset of patients. This study aimed to explore the causes of unexplained galactosemia.
Trio-based exome sequencing and/or Sanger sequencing was performed in eight patients with unexplained congenital galactosemia. In vitro enzymatic assays and immunoblot assays were performed to confirm the pathogenicity of the variants.
The highest blood galactose levels observed in each patient were 17.3-41.9 mg/dl. Bilateral cataracts were observed in two patients. In all eight patients, we identified biallelic variants (p.Arg82*, p.Ile99Leufs*46, p.Gly142Arg, p.Arg267Gly, and p.Trp311*) in the GALM encoding galactose mutarotase, which catalyzes epimerization between β- and α-D-galactose in the first step of the Leloir pathway. GALM enzyme activities were undetectable in lymphoblastoid cell lines established from two patients. Immunoblot analysis showed the absence of the GALM protein in the patients' peripheral blood mononuclear cells. In vitro GALM expression and protein stability assays revealed altered stabilities of the variant GALM proteins.
Biallelic GALM pathogenic variants cause galactosemia, suggesting the existence of type IV galactosemia.
Due to the rapid aging of Japan's population, clinical research focusing on older patients with cancer is urgently needed. The Japan Clinical Oncology Group (JCOG) has conducted several such clinical ...trials, but there has been no formal policy for geriatric research. We have therefore established a JCOG policy for geriatric cancer research. We defined the patient selection policy based on treatment tolerance and chronological age. Older patients are categorized into three conceptual groups: 'fit patients' who can undergo the same standard treatment given to younger patients, 'frail patients' for whom best supportive or palliative care is indicated and 'vulnerable patients' who fall between the fit and frail categories. Unmet needs often exist for vulnerable patients. The policy recommends that study endpoints include not only survival but also other endpoints such as physical and cognitive function because the objective of therapy in older patients is not only extended life expectancy but also maintenance of the patient's general condition. In this viewpoint, co-primary or composite endpoints that incorporate geriatric assessment in the study design are often applicable. Study design will differ depending on the study population, clinical question, and treatment. Even for older patients, a randomized clinical trial is still the gold standard when the clinical question asks which treatment is better. An observational study of a broader population is applicable for investigating actual conditions of older patients. This JCOG Geriatric Research Policy includes several practical solutions for various issues in geriatric research. We plan to revise this policy periodically to guide future geriatric research.
Recently, we reported PPARα-dependent DNA demethylation of the Fgf21 promoter in the postnatal mouse liver, where reduced DNA methylation is associated with enhanced gene expression after PPARα ...activation. However, there is no direct evidence for the effect of site-specific DNA methylation on gene expression. We employed the dCas9-SunTag and single-chain variable fragment (scFv)-TET1 catalytic domain (TET1CD) system to induce targeted DNA methylation of the Fgf21 promoter both in vitro and in vivo. We succeeded in targeted DNA demethylation of the Fgf 21 promoter both in Hepa1-6 cells and PPARα-deficient mice, with increased gene expression response to PPARα synthetic ligand administration and fasting, respectively. This study provides direct evidence that the DNA methylation status of a particular gene may determine the magnitude of the gene expression response to activation cues.
TIR, the thermal infrared imager on Hayabusa2, acquired high-resolution thermal images of the asteroid 162173 Ryugu for one asteroid rotation period on August 1, 2018 to investigate the ...thermophysical properties of the asteroid. The surface temperatures of Ryugu suggest that the surface has a low thermal inertia, indicating the presence of porous materials. Thermophysical models that neglect or oversimplify surface roughness cannot reproduce the flat diurnal temperature profiles observed during daytime. We performed numerical simulations of a thermophysical model, including the effects of roughness on the diurnal brightness temperature, the predictions of which successfully reproduced the observed diurnal variation of temperature. The global thermal inertia was obtained with a standard deviation of 225 ± 45 J m−2 s−0.5 K−1, which is relatively low but still within the range of the value estimated in our previous study (Okada et al., Nature 579, 518–522, 2020), confirming that the boulders on Ryugu are more porous in nature than typical carbonaceous chondrites. The global surface roughness (the ratio of the variance of the height relative to a local horizontal surface length) was determined as 0.41 ± 0.08, corresponding to a RMS surface slope of 47 ± 5°. We identified a slightly lower roughness distributed along the equatorial ridge, implying a mass movement of boulders from the equatorial ridge to the mid-latitudes.
•Thermophysical model using a shape model of rough surface reproduces observations.•We obtain a global thermal inertia of 225 ± 45 J m−2 s−0.5 K−1.•We obtain a global RMS surface slope of 47 ± 5°.•We confirm Ryugu's low global thermal inertia owing to porous constituent boulders.
The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science ...instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al.,
2011
). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of
16
×
12
∘
and a spatial resolution of
0.05
∘
per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al.,
2014
), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.
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