47 research outputs found
Experimental characterization of the electronic structure of anatase TiO2: Thermopower modulation
Thermopower (S) for anatase TiO2 epitaxial films (n3D: 1E17-1E21 /cm3) and
the gate voltage (Vg) dependence of S for thin film transistors (TFTs) based on
TiO2 films were investigated to clarify the electronic density of states (DOS)
around the conduction band bottom. The slope of the |S|-log n3D plots was -20
{\mu}V/K, which is an order magnitude smaller than that of semiconductors (-198
{\mu}V/K), and the |S| values for the TFTs increased with Vg in the low Vg
region, suggesting that the extra tail states are hybridized with the original
conduction band bottom.Comment: 11 pages, 4 figure
Brain Reorganization in Patients with Brachial Plexus Injury: A Longitudinal Functional MRI Study
The aim of this study is to assess plastic changes of the sensorimotor cortex (SMC) in patients with traumatic brachial plexus injury (BPI) using functional magnetic resonance imaging (fMRI).
Twenty patients with traumatic BPI underwent fMRI using blood oxygen level-dependent technique with echo-planar imaging before the operation. Sixteen patients underwent their second fMRI at approximately one year after injury. The subjects performed two tasks: a flexion-extension task of the affected elbow and a task of the unaffected elbow. After activation, maps were generated, the number of significantly activated voxels in SMC contralateral to the elbow movement in the affected elbow task study (Naf) and that in the unaffected task study (Nunaf) were counted. An asymmetry index (AI) was calculated, where AI = (Naf − Nunaf)/(Naf + Nunaf). Ten healthy volunteers were also included in this fMRI study.
The AI of the first fMRI of the patients with BPI was significantly lower than that of the healthy subjects (P = 0.035). The AI of the second fMRI significantly decreased compared with that of the first fMRI (P = 0.045). Brain reorganization associates with peripheral nervous changes after BPI and after operation for functional reconstruction
Signaling emotion in tagclouds
ABSTRACT In order to create more attractive tagclouds that get people interested in tagged content, we propose a simple but novel tagcloud where font size is determined by tag's entropy value, not the popularity to its content. Our method raises users' emotional interest in the content by emphasizing more emotional tags. Our initial experiments show that emotional tagclouds attract more attention than normal tagclouds at first look; thus they will enhance the role of tagcloud as a social signaller
Synthetic data generation method for hybrid image-tabular data using two generative adversarial networks
The generation of synthetic medical records using generative adversarial
networks (GANs) has become increasingly important for addressing privacy
concerns and promoting data sharing in the medical field. In this paper, we
propose a novel method for generating synthetic hybrid medical records
consisting of chest X-ray images (CXRs) and structured tabular data (including
anthropometric data and laboratory tests) using an auto-encoding GAN
({\alpha}GAN) and a conditional tabular GAN (CTGAN). Our approach involves
training a {\alpha}GAN model on a large public database (pDB) to reduce the
dimensionality of CXRs. We then applied the trained encoder of the GAN model to
the images in original database (oDB) to obtain the latent vectors. These
latent vectors were combined with tabular data in oDB, and these joint data
were used to train the CTGAN model. We successfully generated diverse synthetic
records of hybrid CXR and tabular data, maintaining correspondence between
them. We evaluated this synthetic database (sDB) through visual assessment,
distribution of interrecord distances, and classification tasks. Our evaluation
results showed that the sDB captured the features of the oDB while maintaining
the correspondence between the images and tabular data. Although our approach
relies on the availability of a large-scale pDB containing a substantial number
of images with the same modality and imaging region as those in the oDB, this
method has the potential for the public release of synthetic datasets without
compromising the secondary use of data.Comment: 14 page
Evaluation of endometrial thickness in postmenopausal women by using 3.0-T MRI
Background: The accepted threshold for normal endometrial thickness is 5 mm; lesions with endometrial thickness 5 mm areconsidered malignant. However, endometrium ≥ 5 mm on transvaginal ultrasonography inpostmenopausal woman is considered as asymptomatic endometrial thickening. However, recent studies suggest that asymptomatic endometrial thickness of even 8 mm – 11 mm in postmenopausal women may be normal.
Objectives: The present study investigated the normal endometrial thickness range in 297 asymptomatic postmenopausal women using 3.0-T magnetic resonance imaging (MRI) T2-weighted sagittal images measured retrospectively by a single radiologist.
Method: The data were classified according to patient age and postmenopausal duration, and the medical records and follow-up MR images were reviewed to assess the clinical outcome.
Results: The mean endometrial thickness was 2.4 ± 0.1 mm (range: 0.1–11.6). The endometriumin 21 of 297 subjects was ≥ 5 mm thick. Follow-up MR images were obtained in 17 of these 21 women, and their endometrial thickness was found to have decreased in all of them. To date,none of the subjects has been diagnosed with endometrial cancer.
Conclusion: Although 5 mm is considered the conservative threshold of normal endometrial thickness on MRI of postmenopausal women, this figure should not, to avoid excessive false-positive diagnoses, be assumed as an indication of malignancy
Electric-Field Modulation of Thermopower for the KTaO3 Field Effect Transistors
We show herein fabrication and field-modulated thermopower for KTaO3
single-crystal based field-effect transistors (FETs). The KTaO3 FET exhibits
field effect mobility of ~8 cm2/Vs, which is ~4 times larger than that of
SrTiO3 FETs. The thermopower of the KTaO3 FET decreased from 600 to 220
microV/K by the application of gate electric field up to 1.5 MV/cm, ~400
microV/K below that of an SrTiO3 FET, clearly reflecting the smaller carrier
effective mass of KTaO3.Comment: 13 pages, 4 figure
Nonmagnetic framboid and associated iron nanoparticles with a space-weathered feature from asteroid Ryugu
リュウグウ試料に初期太陽系の新しい磁気記録媒体を発見~太陽系磁場の新たな研究手法の確立に期待~.京都大学プレスリリース. 2024-04-30.Extraterrestrial minerals on the surface of airless Solar System bodies undergo gradual alteration processes known as space weathering over long periods of time. The signatures of space weathering help us understand the phenomena occurring in the Solar System. However, meteorites rarely retain the signatures, making it impossible to study the space weathering processes precisely. Here, we examine samples retrieved from the asteroid Ryugu by the Hayabusa2 spacecraft and discover the presence of nonmagnetic framboids through electron holography measurements that can visualize magnetic flux. Magnetite particles, which normally provide a record of the nebular magnetic field, have lost their magnetic properties by reduction via a high-velocity (>5 km s⁻¹) impact of a micrometeoroid with a diameter ranging from 2 to 20 μm after destruction of the parent body of Ryugu. Around these particles, thousands of metallic-iron nanoparticles with a vortex magnetic domain structure, which could have recorded a magnetic field in the impact event, are found. Through measuring the remanent magnetization of the iron nanoparticles, future studies are expected to elucidate the nature of the nebular/interplanetary magnetic fields after the termination of aqueous alteration in an asteroid