MoU with Institut Supérieur des Technologies Médicales de Tunis, Université de Tunis El Manar in Republic of Tunisia - 1st Report

This report addresses the MoU (Memorandum of Understanding) between Institut Supérieur des Technologies Médicales de Tunis, Université de Tunis El Manar (ISTMT-UTM) in the Republic of Tunisia and Morinomiya University of Medical Sciences (MUMS) in Japan. This MoU confirms the mutually cooperative relationship between MUMS and ISTMT-UTM, while aiming to strengthen it by sharing information and views with ISTMT-UTM. Aditionally, the author describes the future efforts to develop medical engineers responsible for the maintenance and inspection of medical equipment exchanged between Japan and Republic of Tunisia

Spatial variation in coda Q around the Nobi fault zone, central Japan: Relation to S-wave velocity and seismicity

We investigate the spatial variation in coda Q around the Nobi fault zone in a high strain rate zone to assess the relation between coda Q, shear wave velocity, and seismicity. Waveform data were obtained from dense seismic observations. Low coda Q that follows the Niigata-Kobe Tectonic Zone in the high strain rate zone is distinct at the lowest frequency band of 1 to 2∈Hz. However, at higher frequencies, such a spatial pattern in coda Q is unclear. A good positive correlation was found between coda Q at the 1- to 2-Hz frequency band and the S-wave velocity perturbation at 25-km depth, which suggests that the coda Q reflects the ductile deformation below the brittle-ductile transition zone. Furthermore, coda Q at the 1- to 2-Hz frequency band correlates negatively with seismicity at 10- to 15-km depth, which implies that there is a high stressing rate in the low coda Q area. These facts, together with results of previous studies, imply that a high deformation rate below the brittle-ductile transition zone produces the high strain rate observed by the Global Positioning System (GPS) on the surface in this region

The association between ultrafiltration rate and mortality in a co- hort of chronic hemodialysis patients with and without diabetes mellitus: a 7-year retrospective observational study.

Background: The ultrafiltration rate (UFR) is one of the important factors involved in long-term mortality in hemodialysis (HD) patients. Presence of diabetes mellitus often affects UFR due to abrupt hypotension during dialysis. In this study, we aimed to find the optimal UFR to improve the mortality in this population with and without diabetes mellitus (DM).Methods: The effect of the UFR on mortality was retrospectively evaluated in 707 patients un- dergoing regular HD from 1 June 2010 to 30 June 2017. The relationship between the UFR and mortality in patients in the non-DM group and those in the DM group was evaluated. Logistic regression analyses were used to select the determinants of mortality. Receiver operating char- acteristic (ROC) curve analyses and survival analysis were used to determine the optimal cutoff points of UFR for mortality.Results: The cutoff UFR values of the non-DM and DM groups were 12.07 ml/hr/kg and 9.66 ml/ hr/kg, respectively. A survival curve showed that in the non-DM group, the 7-year survival rate of patients with a UFR <12.07 ml/hr/kg was 72.6% and that in those with a UFR ≥12.07 ml/hr/kg was 19.6% (p<0.0001). In the DM group, the 7-year survival rate of those with a UFR <9.66 ml/ hr/kg was 66.7%, and it was 33.4% in those with a UFR ≥9.66 ml/hr/kg (p<0.0001).Conclusion: Lower UFR is essential for the long-term mortality of HD patients, and optimal UFR would be different between patients with and without DM

Deadbeat control of power leveling unit with bidirectional buck/boost DC/DC converter

As a distributed generation system increases, a stable power supply becomes difficult. Thus control of power leveling (PL) unit is required to maintain the balance of power flow for irregular power generation. The unit is required to respond to change of voltage and bidirectional power flow. So the bidirectional buck/boost DC/DC converter is applied for the control of PL unit in this research. The PL unit with Electric double-layer capacitor (EDLC) is able to absorb change of power, and it is examined whether the stable power supply is possible. The output current of PL unit is controlled so as to keep power balance and DC bus voltage. The effectiveness of the deadbeat control for power leveling unit is proved in simulation and experiment.7th International Power Electronics Conference, IPEC-Hiroshima - ECCE Asia 2014; Hiroshima; Japan; 18 May 2014 through 21 May 201

Cluster analysis after TAVR

Aims The aim of this study was to identify phenotypes with potential prognostic significance in aortic stenosis (AS) patients after transcatheter aortic valve replacement (TAVR) through a clustering approach. Methods and results This multi-centre retrospective study included 1365 patients with severe AS who underwent TAVR between January 2015 and March 2019. Among demographics, laboratory, and echocardiography parameters, 20 variables were selected through dimension reduction and used for unsupervised clustering. Phenotypes and outcomes were compared between clusters. Patients were randomly divided into a derivation cohort (n = 1092: 80%) and a validation cohort (n = 273: 20%). Three clusters with markedly different features were identified. Cluster 1 was associated predominantly with elderly age, a high aortic valve gradient, and left ventricular (LV) hypertrophy; Cluster 2 consisted of preserved LV ejection fraction, larger aortic valve area, and high blood pressure; and Cluster 3 demonstrated tachycardia and low flow/low gradient AS. Adverse outcomes differed significantly among clusters during a median of 2.2 years of follow-up (P < 0.001). After adjustment for clinical and echocardiographic data in a Cox proportional hazards model, Cluster 3 (hazard ratio, 4.18; 95% confidence interval, 1.76–9.94; P = 0.001) was associated with increased risk of adverse outcomes. In sequential Cox models, a model based on clinical data and echocardiographic variables (χ2 = 18.4) was improved by Cluster 3 (χ2 = 31.5; P = 0.001) in the validation cohort. Conclusion Unsupervised cluster analysis of patients after TAVR revealed three different groups for assessment of prognosis. This provides a new perspective in the categorization of patients after TAVR that considers comorbidities and extravalvular cardiac dysfunction

Development of the ARICA-2 Satellite Using Spresense as an Onboard Computer

Gamma-ray bursts (GRBs) are transient astronomical phenomena that emit enormous amounts of energy in electromagnetic waves, mainly in the gamma-ray range, for several seconds to tens of seconds. GRB observations are challenging because of the difficulty in predicting the location and time of occurrence and its extremely short duration. Therefore, it is necessary to notify about the discovery in space and to conduct follow-up observations by researchers. The AGU Remote Innovative CubeSat Alert system-2 (ARICA-2) has been developed to demonstrate a new alert system using commercial satellite network services. ARICA-2 uses SONY’s Spresense as its onboard computer (OBC). We manufactured the special board to attach two Spresenses as a redundancy of the OBC system. We will present the system development of ARICA-2 using Spresense

Power System Development of the AGU Remote Innovative CubeSat Alert System -2 – ARICA-2

We present the power system development of the 2U CubeSat, AGU Remote Innovative CubeSat Alert system -2(ARICA-2). The main goal of the ARICA-2 project is to demonstrate the real-time alert system of transient astronomical sources using commercial satellite network devices. 1U CubeSat ARICA was launched in November 2021. However, we have not been able to send and receive the data at this point. Therefore, we started developing 2U CubeSat ARICA-2, which is an improved version of ARICA, in April 2022. One of the possible causes of the communication problem of ARICA is the power system, such as a negative power budget or a failure in the installation of the inhibit switches. ARICA-2 is upsized from 1U to 2U to ensure a sufficient power generation and is equipped with improved inhibit switches. The calculation of power consumption and simulation of power supply on orbit have been finished. We confirmed the performance of our Electric Power System (EPS) and the health of the installed batteries. We are currently in the EM development phase with the goal of launching in Japanese fiscal year 2024

Overview and Status of AGU Remote Innovative Cubesat Alert System-2 on 2023

We present the overview of the 2U CubeSat, AGU Remote Innovative Cubesat Alert system - 2 (ARICA-2). ARICA-2 was selected as a feasibility study phase of the JAXA-Small Satellite Rush Program (JAXA-SMASH) and the JAXA Innovative Satellite Technology Demonstration-4 project in 2022. The main goal of ARICA-2 is to demonstrate the real-time alert system of transient astronomical sources, such as gamma-ray bursts, using commercial satellite network services. The first 1U CubeSat ARICA, which had the same mission goal as ARICA-2, was successfully launched in 2021 by the JAXA’s Epsilon rocket No.5. However, communication with ARICA has yet to be established due to severe hardware issues. Therefore, ARICA-2 is the re-challenging mission of ARICA. ARICA-2 has several different features compared to ARICA. First, a transceiver using amateur radio frequency is added to the commercial satellite network devices to communicate directly from the ground. Second, ARICA-2 uses Sony’s low-power board Spresense as an onboard computer. Third, the attitude control system using magnetorquer is installed to establish better communication with the commercial network satellites. Fourth, the size of a gamma-ray detector is 70 mm x 70 mm x 10 mm, which is larger by a factor of 200 in volume compared to ARICA, to enhance the detection rate of gamma-ray bursts. We plan to develop the engineering model (EM) in 2023 and perform thermal vacuum and vibration tests on the EM. We report the current status and a prospect of ARICA-2