Akira Suda

Hamamatsu Photonics (Japan)

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Amplifier characterlstics of an electron-beam-excited Kr-rich KrF laser mixture in the strongly saturated region

Conference on Lasers and Electro-Optics (1987)

Akira Suda Hiroshi Kumagai Shuhei Ashi-Date Yutaka Kodaira Minoru Obara

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Comparative study of low‐pressure rare‐gas fluoride/chloride lasers excited by a short‐pulse electron beam

Journal of Applied Physics (1988)

Akira Suda Hiroshi Kumagai Shingo Izawa Minoru Obara

Output characteristics of the short-pulse electron-beam excited ArF (193 nm), KrF (248 nm), XeF (351 nm), KrCl (222 nm), and XeCl (308 nm) lasers were experimentally investigated at the same time on the same device for various mixtures all pumped at a high excitation rate of 2.3 MW/cm3. The optimum pressure of rare gas forming its rare-gas halide excimer increased for the sequence of ArF, KrCl, KrF, XeCl, and XeF, indicating that rare-gas halides were more quenched by the heavier rare gases, such as Xe, even at near-atmospheric pressures. At nearly atmospheric pressures the Ar-buffered mixtures gave higher laser energy than Ne-buffered mixtures except for the XeF laser. Through a series of measurements, the ArF laser showed the best result on the output energy of 96 J (5 J/ℓ ) with an intrinsic efficiency of 3.4%.

Excimer

Gas laser

10.1063/1.341766

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Citations (3)

1343Evidence for impaired vasodilator capacity of coronary microvessels in patients with vasospatic angina - Myocardial CT perfusion imaging study

European Heart Journal (2018)

Jun Sugisawa Yasuharu Matsumoto Akira Suda Hideki Ota Satoshi Tsuchiya

frequently observed in patients with implantable cardioverter defibrillators (ICD).Conversely AT/AF incidence in the single chamber ICD patients has been reported to be between 2 and 5%, possibly due to monitoring limits and to the fact that AT/AF are frequently asymptomatic.Purpose: To evaluate real AT/AF incidence in patients with no history of AT/AF, no anti-arrhythmic drug (AAD) therapy and wearing a new-generation single chamber ICD with specific AT/AF diagnostics.Methods: Consecutive single-chamber ICD patients were prospectively followed by 23 Italian cardiologic centers in an observational research.Clinical and device data were collected and reviewed by expert cardiologists to assess AT/AF occurrence through in clinic visit and/or remote transmissions of device data.Results: 94 (83.1% male, 60 years old, 55% with a CHA2DS2-VASc≥2) were followed for a median observation period of 389 days.AT/AF episodes occurred in 22 (23.4%)patients when considering at least 5 minutes duration, in 16 (17%) for AT/AF ≥1 hours, in 10 (10.6%) for AT/AF ≥6 hours, in 4 (4%) for AT/AF ≥1 day.Conclusions: Our multicenter real-world experience in a population of single chamber ICD patients with no history of AT/AF shows that a relevant percentage of patients develops new onset AT/AF in 1 year follow-up.Compared with literature data, the use of a specific AF diagnostics allowed cardiologists to improve the knowledge about patients with AT/AF and at risk of stroke and to optimize AT/AF management in terms of oral anticoagulation, and rate-control or rhythm control strategies.

Coronary vasodilator

Coronary circulation

10.1093/eurheartj/ehy565.1343

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Citations (1)

Pointing stabilization of a high-repetition-rate high-power femtosecond laser for intense few-cycle pulse generation

Applied Physics Letters (2008)

Takuya Kanai Akira Suda Samuel Bohman Masanori Kaku Shigeru Yamaguchi

We have developed a beam stabilization system for high-power femtosecond lasers operating at a repetition rate of 1kHz. The beam pointing at a hollow fiber input was stabilized to within 1μm rms and the fluctuations of the broadened spectra and power were significantly improved. This technique enables us to increase the input power to a hollow fiber for intense few-cycle pulse generation.

Repetition (rhetorical device)

10.1063/1.2842414

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Citations (42)

Ablation of burn eschar by excimer laser irradiation

Conference on Lasers and Electro-Optics (1990)

Tunenori Arai Akira Suda Makoto Kikuchi Akimi Iwaya Katsuyuki Arai

Eschar

Laser Ablation

Photoablation

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1057Important prognostic impact of comorbid coronary microvascular dysfunction in patients with vasospastic angina

European Heart Journal (2017)

Akira Suda Jun Takahashi Kiyotaka Hao Yoku Kikuchi Tomohiko Shindo

blood pressure despite similar rates of prescription and doses of beta-blockers and RAAS inhibitors.After multivariate analysis, only the AHA risk score (OR (95% CI): 1.07 (1.04-1.10),p<0.001) and LVEF (OR (95% CI): 0.95 (0.92-0.98), p=0.002) were significantly and independently associated with the lowest tertile of retinal vascular density measured by OCT angiography.The strong association between the AHA risk score and vascular density was confirmed by a significant Pearson correlation coefficient, (R= -0.48, p<0.001). Conclusion:Retinal inner vascular density found with OCT angiography was strongly associated with cardiovascular risk and with impaired LVEF in patients admitted for ACS.These preliminary results could help to target a specific population at high risk for cardiovascular events.

Vasospastic angina

10.1093/eurheartj/ehx502.1057

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Novel Operational Regime Of High-Efficiency KrF Lasers

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE (1984)

Minoru Obara Tomoo Fujioka Fumihiko Kannari Akira Suda

The novel operational regime of high-efficiency KrF lasers is presented. The excitation sources are intense electron beams and intense proton beams. Theoretical evaluation of electron-beam-excited KrF laser using one atmospheric-pressure, argon-free mixtures showed that by using high-excitation-rate and shorter-excitation-pulsewidth pumping, higher intrinsic laser efficiency than conventional argon-rich, high-pressure mixtures is attainable. The experimental results are also presented.

Electron excitation

Gas laser

10.1117/12.942566

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Citations (2)

1059Evidence for enhanced inflammation of coronary adventitia and perivascular adipose tissue in patients with vasospastic angina - a multi-modality imaging study-

European Heart Journal (2017)

Kazuma Ohyama Yasuharu Matsumoto Kentaro Takanami Hideki Ota Kojiro Nishimiya

Adventitia

Modality (human–computer interaction)

10.1093/eurheartj/ehx502.1059

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Control of spectral distribution of Raman sidebands in impulsively stimulated rotational Raman scattering

Applied Physics Letters (2002)

Hiroyuki Kawano Akira Suda Katsumi Midorikawa

We investigate the dependence of the intensity distribution of the impulsively stimulated rotational Raman sidebands from hydrogen gas on the polarization of the prepump and pump pulses. The results show that the energy flow direction of the pump pulse can be confined to either the Stokes side or the anti-Stokes side by changing the polarization of the 60 fs pump pulse. It is found that the use of a linearly polarized pump pulse is the most effective way to generate the largest number of Raman components as possible.

Rotational energy

Spectral power distribution

Optical Pumping

10.1063/1.1446989

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Citations (8)

Petahertz optical drive with wide-bandgap semiconductor

Nature Physics (2016)

Hiroki Mashiko Katsuya Oguri Tomohiko Yamaguchi Akira Suda Hideki Gotoh

Attosecond

Indium gallium nitride

10.1038/nphys3711

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Citations (129)