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A portable microwave‐excited atmospheric pressure plasma jet (APPJ) using a coaxial transmission line resonator is introduced for applications of plasma biomedicine. Its unique feature includes the portability and no need for matching network and cooling system with high power efficiency, operating at 900 MHz with low ignition power less than 2.5 W in argon at atmospheric pressure. The temperature at the downstream of the APPJ stays less than 47 °C (≈320 K) during 5 min of continuous operation. The optical emission spectrum of the APPJ shows various reactive radicals such as OH, NO, and O which are responsible for biomedicine. The APPJ was applied to investigate the acceleration of blood coagulation, which occurred within 20 s of plasma treatment in vitro and within 1 min in vivo. This is significantly faster than the natural coagulation.

Looking into temporal dynamics of the reactive flux that is precisely located at the well-characterized conical intersection has been one of chemists' longstanding goals. We report here real-time nonadiabatic bifurcation dynamics in the S-CH bond predissociation of thioanisole (CHSCH) in the first electronically excited state (S). It is found that two distinct adiabatic and nonadiabatic reaction pathways are activated simultaneously only when the vibronic state near the first conical intersection is optically accessed. Our time-resolved measurement of the product state distribution could separate two different dynamic channels unambiguously, unraveling the detailed dynamic mechanism of the nonadiabatic reaction taking place in the vicinity of the conical intersection. The nonadiabatic channel, where the reactive flux funnels through two consecutive conical intersections along the reaction coordinate, is found to be significantly faster than the adiabatic channel along the minimum energy reaction pathway. The kinetic energy release ratio and the nonadiabatic transition probability are found to be much higher for the nonadiabatic channel than those of the adiabatic channel, giving insights into the bifurcation dynamics occurring at the conical intersection.

Multidimensional facets of the hydrogen tunneling dynamics of phenol excited in S1 (ππ*) have been unraveled to give particular S1 vibronic states strongly coupled or actively decoupled to the O–H tunneling coordinate. Strong mode-dependent variation of the tunneling rate measured with picosecond lasers indicates that tunneling probability is extremely sensitive to low-frequency vibrational modes seemingly orthogonal to the O–H elongation coordinate unless the rate of energy randomization exceeds that of tunneling. The multidimensional nature of tunneling has also been manifested in efficient internal-to-translational energy transfers observed at S1 vibronic modes strongly coupled to the tunneling coordinate, giving insights into otherwise the formidable multidimensional map of tunneling process. The nonadiabatic bifurcation dynamics in the later stage of the chemical reaction has been disentangled by analyzing picosecond time-resolved product state distributions, resolving a long controversial issue regarding the origin of high or low kinetic energy component of the product translational energy distributions.

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