Stroboscopic oblique-incidence interferometer for motion visualization of stator of ultrasonic motor.

AbstractThis paper describes a motion-visualization technique for an ultrasonic motor (USM) by using a stroboscopic oblique-incidence interferometer. Characteristics of USM depend on a vibration mode of a stator which is one of main component of USM. Though there are some visualization techniques of its vibrated mode, it is difficult to visualization. Because the surface of the stator is rough for a light. For visualization such a surface, we focused on an oblique-incidence interferometer. The interferometer is well suited to analyze the rough surface because a scattering at the rough surface is reduced by using an oblique-incidence light. Furthermore, for detecting a vibrated surface, a pulsed light synchronized with stator was used as light source. We have succeeded to detect a periodically movement of fringe patterns of the vibrated stator

Relationship between Psychological Stress Determined by Voice Analysis and Periodontal Status: A Cohort Study

In modern society, evaluation and management of psychological stress may be important for the prevention of periodontal disease. The purpose of this study was to examine the relationship between psychological stress (vitality and mental activity) evaluated by Mind Monitoring System (MIMOSYS) and periodontal status. Forty students of Okayama University underwent the oral examination and self-reported questionnaire on the first day (baseline) and the 14th day (follow-up). Voice recording was performed every day with the MIMOSYS app during the whole study period. The participants completed the Patient Health Questionnaire (PHQ)-9 and Beck Depression Inventory (BDI) at baseline and at follow-up. Spearman's rank correlation coefficient was used to determine the significance of correlations among variables. The PHQ-9 and BDI scores were negatively correlated with vitality in the morning. Change in vitality in the morning was significantly correlated with changes in periodontal inflammation. Mental activity was significantly correlated with change in mean probing pocket depth. This result shows that measurement of psychological stress using a voice-based tool to assess mental health may contribute to the early detection of periodontal disease

A tri-axial accelerometer with structure-based voltage operation by using series-connected piezoelectric elements

AbstractOutput-voltage operation on a sensor structure is proposed and a tri-axial accelerometer with low cross-axis sensitivities is designed. The output voltage between the electrodes sandwiching piezoelectric thin-films on a deforming structure is proportional to the in-plane stress of the piezoelectric thin-film. If the piezoelectric thin-film is processed to separated elements and the electrodes of the elements are connected in series, the output voltages from the series-connected piezoelectric elements are multiplied or canceled depending on the situations of the internal-stresses (i.e. compressive or tensile) of the elements. Proper design of the electrode connections by taking the deformation shape of structures into consideration can realize expected outputvoltage operations on the device structure. The principle of structure-based output-voltage operation is applied to the design of a tri-axial accelerometer with low cross-axes sensitivities. Finite-element-method (FEM) simulations of the tri-axial accelerometer revealed the cross-axis sensitivity of less than 1.5%

Performance evaluation of fifth-generation ultra-high-resolution SPECT system with two stationary detectors and multi-pinhole imaging

Background Small-animal single-photon emission computed tomography (SPECT) systems with multi-pinhole collimation and large stationary detectors have advantages compared to systems with moving small detectors. These systems benefit from less labour-intensive maintenance and quality control as fewer prone parts are moving, higher accuracy for focused scans and maintaining high resolution with increased sensitivity due to focused pinholes on the field of view. This study aims to investigate the performance of a novel ultra-high-resolution scanner with two-detector configuration (U-SPECT5-E) and to compare its image quality to a conventional micro-SPECT system with three stationary detectors (U-SPECT+). Methods The new U-SPECT5-E with two stationary detectors was used for acquiring data with Tc-99m-filled point source, hot-rod and uniformity phantoms to analyse sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR). Three dedicated multi-pinhole mouse collimators with 75 pinholes each and 0.25-, 0.60- and 1.00-mm pinholes for extra ultra-high resolution (XUHR-M), general-purpose (GP-M) and ultra-high sensitivity (UHS-M) imaging were examined. For CNR analysis, four different activity ranges representing low- and high-count settings were investigated for all three collimators. The experiments for the performance assessment were repeated with the same GP-M collimator in the three-detector U-SPECT+ for comparison. Results Peak sensitivity was 237 cps/MBq (XUHR-M), 847 cps/MBq (GP-M), 2054 cps/MBq (UHS-M) for U-SPECT5-E and 1710 cps/MBq (GP-M) for U-SPECT+. In the visually analysed sections of the reconstructed mini Derenzo phantoms, rods as small as 0.35 mm (XUHR-M), 0.50 mm (GP-M) for the two-detector as well as the three-detector SPECT and 0.75 mm (UHS-M) were resolved. Uniformity for maximum resolution recorded 40.7% (XUHR-M), 29.1% (GP-M, U-SPECT5-E), 16.3% (GP-M, U-SPECT+) and 23.0% (UHS-M), respectively. UHS-M reached highest CNR values for low-count images; for rods smaller than 0.45 mm, acceptable CNR was only achieved by XUHR-M. GP-M was superior for imaging rods sized from 0.60 to 1.50 mm for intermediate activity concentrations. U-SPECT5-E and U-SPECT+ both provided comparable CNR. Conclusions While uniformity and sensitivity are negatively affected by the absence of a third detector, the investigated U-SPECT5-E system with two stationary detectors delivers excellent spatial resolution and CNR comparable to the performance of an established three-detector-setup

Surface Shape Measurement by Grating Projection Method in Aerospace Structures

To improve the accuracy of the grating projection method of a surface shape measurement method without contact, several attempts are proposed and verified. A whole-space tabulation method (WSTM) is demonstrated to measure a translucent glittering metallic mesh of a parabolic antenna for a radio astronomy satellite. A transparence method of the grating projection method is proposed to measure a glossy polymer film often used in space structures. An extrapolation method is proposed to measure a larger object than the reference planes. A pre-calibration can be used to adjust the measured value to the real values. The extrapolation method and the pre-calibration are demonstrated to measure a displacement of a wing of a developing airplane under loading.特集 : 航空宇宙機システム研究センターにおける開発研究2 : 5. オオワシII飛行にむけて並びに関連技術の研究開発（関連研究開発分野

Simultaneous staining of Ki-67 and chromosome 8 in invasive ductal carcinoma: association with prognosis

Introduction: This study aimed to evaluate an approach that uses simultaneous staining to estimate malignant potential. This approach combines immunofluorescence (IF) staining for Ki-67 expression with fluorescence in situ hybridization (FISH) for copy number aberrations (CNA) of chromosome 8 in breast cancer cells.Methods: In 50 specimens of invasive ductal carcinoma (IDC), we examined a method that simultaneously combined immunostaining (Ki-67) and FISH with a chromosome 8 centromere-specific probe. Breast cancer cells were classified into Group 1, Ki-67 positive and chromosomal aberrant; Group 2, Ki-67 negative and chromosomal aberrant; Group 3, Ki-67 positive and chromosomal wild; Group 4, Ki-67 negative and chromosomal wild.Results: The frequency of Group 1 was significantly associated with nodal metastasis (p<0.05) and patient prognosis (p<0.05); however, it was not associated with age, tumor size, estrogen receptor status, progesterone receptor status, or histological type. Furthermore, Group 1-positive cases showed a significantly worse prognosis, as shown by the Kaplan-Meier method.Conclusions: We successfully stained for Ki-67 expression and CNA of chromosome 8 in breast tumor sections (n=50). This approach indicated that Ki-67-positive cells with aberrant chromosome 8 were associated with malignant potential in IDC

An Analytical Latency Model and Evaluation of the Capacity of 5G NR to Support V2X Services Using V2N2V Communications

5G has been designed to support applications such as connected and automated driving. To this aim, 5G includes a highly flexible New Radio (NR) interface that can be configured to utilize different subcarrier spacings (SCS), slot durations, scheduling, and retransmissions mechanisms. This flexibility can be exploited to support advanced V2X services with strict latency and reliability requirements using V2N2V (Vehicle-to-Network-to-Vehicles) communications instead of direct or sidelink V2V (Vehicle-to-Vehicle). To analyze this possibility, this paper presents a novel analytical model that estimates the latency of 5G at the radio network level. The model accounts for the use of different numerologies (SCS, slot durations and Cyclic Prefixes), modulation and coding schemes, full-slots or mini-slots, semi-static and dynamic scheduling, different retransmission mechanisms, and broadcast/multicast or unicast transmissions. The model has been used to first analyze the impact of different 5G NR radio configurations on the latency. We then identify which radio configurations and scenarios can 5G NR satisfy the latency and reliability requirements of V2X services using V2N2V communications. This paper considers cooperative lane changes as a case study. The results show that 5G can support advanced V2X services at the radio network level using V2N2V communications under certain conditions that depend on the radio configuration, bandwidth, service requirements and cell traffic load

Capabilities of multi-pinhole SPECT with two stationary detectors for in vivo rat imaging

We aimed to investigate the image quality of the U-SPECT5/CT E-Class a micro single-photon emission computed tomography (SPECT) system with two large stationary detectors for visualization of rat hearts and bones using clinically available Tc-99m-labelled tracers. Sensitivity, spatial resolution, uniformity and contrast-to-noise ratio (CNR) of the small-animal SPECT scanner were investigated in phantom studies using an ultra-high-resolution rat and mouse multi-pinhole collimator (UHR-RM). Point source, hot-rod, and uniform phantoms with Tc-99m-solution were scanned for high-count performance assessment and count levels equal to animal scans, respectively. Reconstruction was performed using the similarity-regulated ordered-subsets expectation maximization (SROSEM) algorithm with Gaussian smoothing. Rats were injected with similar to 100 MBq [Tc-99m]Tc-MIBI or similar to 150 MBq [Tc-99m]Tc-HMDP and received multi-frame micro-SPECT imaging after tracer distribution. Animal scans were reconstructed for three different acquisition times and post-processed with different sized Gaussian filters. Following reconstruction, CNR was calculated and image quality evaluated by three independent readers on a five-point scale from 1="very poor" to 5="very good". Point source sensitivity was 567 cps/MBq and radioactive rods as small as 1.2 mm were resolved with the UHR-RM collimator. Collimator-dependent uniformity was 55.5%. Phantom CNR improved with increasing rod size, filter size and activity concentration. Left ventricle and bone structures were successfully visualized in rat experiments. Image quality was strongly affected by the extent of post-filtering, whereas scan time did not have substantial influence on visual assessment. Good image quality was achieved for resolution range greater than 1.8 mm in bone and 2.8 mm in heart. The recently introduced small animal SPECT system with two stationary detectors and UHR-RM collimator is capable to provide excellent image quality in heart and bone scans in a rat using standardized reconstruction parameters and appropriate post-filtering. However, there are still challenges in achieving maximum system resolution in the sub-millimeter range with in vivo settings under limited injection dose and acquisition time