222 research outputs found

    Image-based evaluation of contraction–relaxation kinetics of human-induced pluripotent stem cell-derived cardiomyocytes: Correlation and complementarity with extracellular electrophysiology

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    AbstractIn this study, we used high-speed video microscopy with motion vector analysis to investigate the contractile characteristics of hiPS-CM monolayer, in addition to further characterizing the motion with extracellular field potential (FP), traction force and the Ca2+ transient. Results of our traction force microscopy demonstrated that the force development of hiPS-CMs correlated well with the cellular deformation detected by the video microscopy with motion vector analysis. In the presence of verapamil and isoproterenol, contractile motion of hiPS-CMs showed alteration in accordance with the changes in fluorescence peak of the Ca2+ transient, i.e., upstroke, decay, amplitude and full-width at half-maximum. Simultaneously recorded hiPS-CM motion and FP showed that there was a linear correlation between changes in the motion and field potential duration in response to verapamil (30–150nM), isoproterenol (0.1–10μM) and E-4031 (10–50nM). In addition, tetrodotoxin (3–30μM)-induced delay of sodium current was corresponded with the delay of the contraction onset of hiPS-CMs. These results indicate that the electrophysiological and functional behaviors of hiPS-CMs are quantitatively reflected in the contractile motion detected by this image-based technique. In the presence of 100nM E-4031, the occurrence of early after-depolarization-like negative deflection in FP was also detected in the hiPS-CM motion as a characteristic two-step relaxation pattern. These findings offer insights into the interpretation of the motion kinetics of the hiPS-CMs, and are relevant for understanding electrical and mechanical relationship in hiPS-CMs

    PETREL for Astrophysics and Carbon Business

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    A multi-purpose 50kg class microsatellite hosting astrophysical mission and earth remote sensing, PETREL , will be launched in 2023. In the night side, PETREL observe the ultra-violet sky with a wide-field telescope covering 50 deg^2 for surveying transient objects related to supernovae, tidal disruption events, and gravitational wave events. Our UV telescope can detect the early phase UV emission from a neutron star merger occurred within 150 Mpc. In addition to the satellite observation, PETREL sends a detection alert including the coordinate and brightness of the UV transient to the ground via the real time communication network within several minutes after detection to conduct follow-up observations with the collaborating ground based observatories over the world. In the day side, PETREL observes the surface of the earth by using the tunable multi-spectral cameras and a ultra-compact hyperspectral camera. Our potential targets are the tropical forests (Green Carbon) and coastal zones (Blue Carbon) in the tropical areas to evaluating the global biological carbon strages. For this purpose PETREL will conduct multiple scale mapping collaborating with drones and small aircraft not only satellite. The obtained data will be used for academical research and for business applications. The technical difficulty of this satellite is that carries out multi-purpose with different requirements, such as astronomical observations which requires a quite high attitude stability and the earth observations requiring a high pointing accuracy, with limited resources. If it is possible, a novel small satellite system or a business style can be realized that can share the payload with academia and industry. PETREL has been adopted as Innovative Satellite Technology Demonstration Program No.3 led by JAXA, and development is underway with the aim of launching in FY2023

    PETREL: Platform for Extra and Terrestrial Remote Examination with LCTF

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    A small satellite ”PETREL” for UV astronomy and remote sensing with ”tunable” multi-spectral cameras conducted by an academia-industrial collaboration is presented. This project was originally proposed by an astronomer who desired a satellite for exploration of explosive objects in ultraviolet. To avoid the earthshine the astronomical observations are scheduled only in the nighttime. To utilize the daytime more electively we conceived a plan of ”satellite sharing” with the industrial collaborators, that can also reduce the developing cost drastically. The daytime mission is spectroscopy that is one of the potential fields in terms of data business, because that can provide chemical and biological information on the surface of the earth. We employ multi-spectral cameras making use of liquid crystal tunable filters (LCTFs) that enable adaptive observations at the optimized wave-bands for each targets. In 2020, this remote-sensing project and ultraviolet astronomy mission were accepted as a small satellite project of JAXA’s Innovative Satellite Technology Demonstration program and as an ISAS/JAXA’s small-scale program, respectively. This satellit

    Efficacy and Safety of Intravitreal Aflibercept Treat-and-Extend Regimens in Exudative Age-Related Macular Degeneration: 52- and 96-Week Findings from ALTAIR : A Randomized Controlled Trial.

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    PURPOSE:To evaluate efficacy and safety of intravitreal injections of aflibercept (IVT-AFL) treat-and-extend (T&E) dosing regimens in treatment-naïve patients with exudative age-related macular degeneration (AMD).METHODS:Adults aged at least 50 years old with exudative AMD and best-corrected visual acuity (BCVA) of 73-25 Early Treatment Diabetic Retinopathy Study (ETDRS) letters were included. Patients received three monthly doses of IVT-AFL 2 mg. At week 16, patients were randomized 1:1 to IVT-AFL T&E with either 2- or 4-week adjustments. The primary endpoint was mean change in BCVA from baseline to week 52. Outcomes were assessed at weeks 52 and 96.RESULTS:Baseline characteristics were comparable between the groups (n = 123 each). Over 52 weeks, mean number of injections was 7.2 and 6.9 and mean last injection interval was 10.7 and 11.8 weeks, for the 2- and 4-week groups, respectively. From baseline, mean change in BCVA was + 9.0 and + 8.4 letters (week 52) and + 7.6 and + 6.1 letters (week 96); mean change in central retinal thickness was - 134.4 µm and - 126.1 µm (week 52) and - 130.5 µm and - 125.3 µm (week 96). Last injection interval before week 52 was at least 12 weeks in 42.3% and 49.6% of patients and 56.9% and 60.2% before week 96. Over 96 weeks, mean number of injections was 10.4 (both groups). The safety profile of IVT-AFL was consistent with previous reports.CONCLUSIONS:IVT-AFL administered using two different T&E regimens for treatment-naïve exudative AMD improved functional and anatomic outcomes at week 52 and outcomes were maintained to week 96. Outcomes were similar between the 2- and 4-week groups.TRIAL REGISTRATION:ClinicalTrials.gov identifier, NCT02305238

    The current status of thrombosis and anticoagulation therapy in patients with COVID-19 in Japan: From the CLOT-COVID study

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    BACKGROUND: Data on thrombosis and current real-world management strategies for anticoagulation therapy are scarce but important for understanding current issues and unmet needs of an optimal management of patients with coronavirus disease 2019 (COVID-19). METHOD: The CLOT-COVID Study (thrombosis and antiCoaguLatiOn Therapy in patients with COVID-19 in Japan Study: UMIN000045800) was a retrospective, multicenter cohort study enrolling consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021, and we tried to capture the status of the patients in the fourth and fifth waves of the COVID-19 infections in Japan. We enrolled consecutive hospitalized patients who were diagnosed with COVID-19 and had a positive polymerase chain reaction test obtained from the hospital databases. RESULTS: Among 2894 patients with COVID-19, 1245 (43%) received pharmacological thromboprophylaxis. The proportion of pharmacological thromboprophylaxis increased according to the severity of the COVID-19 in 9.8% with mild COVID-19, 61% with moderate COVID-19, and 97% with severe COVID-19. The types and doses of anticoagulants varied widely across the participating centers. During the hospitalization, 38 patients (1.3%) and 126 (4.4%) underwent ultrasound examinations for the lower extremities and contrast-enhanced computed tomography examinations, respectively, and 55 (1.9%) developed thrombosis, mostly venous thromboembolism (71%). The incidence of thrombosis increased according to the severity of the COVID-19 in 0.2% with mild COVID-19, 1.4% with moderate COVID-19, and 9.5% with severe COVID-19. Major bleeding occurred in 57 patients (2.0%) and 158 (5.5%) died, and 81% of them were due to respiratory failure from COVID-19 pneumonia. CONCLUSIONS: In the present large-scale observational study, pharmacological thromboprophylaxis for hospitalized patients with COVID-19 was common especially in patients with severe COVID-19, and management strategies varied widely across the participating centers. The overall incidence of thrombosis was substantially low with an increased incidence according to the severity of the COVID-19

    Significant Impact of Age on Mortality and Non-significant Impact of Age on Thrombosis and Major Bleeding in Patients with COVID-19: From the CLOT-COVID Study.

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    AIM: There is scarce data on the impact of age on clinical outcomes in patients with coronavirus disease 2019 (COVID-19). METHOD: The CLOT-COVID Study was a retrospective, multicenter cohort study enrolling 2894 consecutive hospitalized patients with COVID-19 among 16 centers in Japan from April 2021 to September 2021. We divided the entire cohort into five groups according to age strata; -19, 20-39, 40-59, 60-79, and 80- years. RESULTS: Most patients under 19 had mild COVID-19 on admission (99%), while older patients had more severe COVID-19. The incidence rates of clinical outcomes during hospitalization in patients aged ≤ 19, 20-39, 40-59, 60-79, and 80 ≥ years were 0.0%, 0.5%, 2.2%, 2.7%, and 1.5% for thrombosis; 0.0%, 1.2%, 1.5%, 3.4%, and 2.0% for major bleeding; and 0.0%, 0.4%, 2.0%, 12.1%, and 16.8% for all-cause death, respectively. In the stratified analysis according to COVID-19 severity on admission, the incidences of thrombosis were generally higher among patients with more severe status, although those were not significantly different among age strata in all sub-types of COVID-19 severity. However, the incidences of all-cause death were significantly higher with increasing age in all sub-types of COVID-19 severity. CONCLUSIONS: In the current large observational study of patients with COVID-19, the risk of mortality became markedly higher with increased age. However, the risks of thrombosis and major bleeding did not necessarily increase as age increases, which seemed to be consistent irrespective of COVID-19 severity on admission

    Survey of Period Variations of Superhumps in SU UMa-Type Dwarf Novae. II: The Second Year (2009-2010)

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    As an extension of the project in Kato et al. (2009, arXiv:0905.1757), we collected times of superhump maxima for 61 SU UMa-type dwarf novae mainly observed during the 2009-2010 season. The newly obtained data confirmed the basic findings reported in Kato et al. (2009): the presence of stages A-C, as well as the predominance of positive period derivatives during stage B in systems with superhump periods shorter than 0.07 d. There was a systematic difference in period derivatives for systems with superhump periods longer than 0.075 d between this study and Kato et al. (2009). We suggest that this difference is possibly caused by the relative lack of frequently outbursting SU UMa-type dwarf novae in this period regime in the present study. We recorded a strong beat phenomenon during the 2009 superoutburst of IY UMa. The close correlation between the beat period and superhump period suggests that the changing angular velocity of the apsidal motion of the elliptical disk is responsible for the variation of superhump periods. We also described three new WZ Sge-type objects with established early superhumps and one with likely early superhumps. We also suggest that two systems, VX For and EL UMa, are WZ Sge-type dwarf novae with multiple rebrightenings. The O-C variation in OT J213806.6+261957 suggests that the frequent absence of rebrightenings in very short-Porb objects can be a result of sustained superoutburst plateau at the epoch when usual SU UMa-type dwarf novae return to quiescence preceding a rebrightening. We also present a formulation for a variety of Bayesian extension to traditional period analyses.Comment: 63 pages, 77 figures, 1 appendix, Accepted for publication in PASJ, data correctio
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