Taisuke Hasegawa

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Interfacial water structures have been studied intensively by probing the O-H stretch mode of water molecules using sum-frequency generation (SFG) spectroscopy. This surface-specific technique is finding increasingly widespread use, and accordingly, computational approaches to calculate SFG spectra using molecular dynamics (MD) trajectories of interfacial(More)
The fifth-order two-dimensional (2D) Raman signals have been calculated from the equilibrium and nonequilibrium (finite field) molecular dynamics simulations. The equilibrium method evaluates response functions with equilibrium trajectories, while the nonequilibrium method calculates a molecular polarizability from nonequilibrium trajectories for different(More)
The long held objective of directly observing atomic motions during the defining moments of chemistry has been achieved based on ultrabright electron sources that have given rise to a new field of atomically resolved structural dynamics. This class of experiments requires not only simultaneous sub-atomic spatial resolution with temporal resolution on the(More)
We present a combined molecular dynamics simulation and experimental study on the water bending mode at the water-vapor interface using sum-frequency generation (SFG) spectroscopy. The SFG spectrum simulated using an ab initio-based water model shows good agreement with the experimental data. The imaginary part of the SFG response shows a negative peak at(More)
The fifth-order two-dimensional (2D) Raman spectrum of liquid formamide has been obtained. The absolute signal levels, qualitative features, as well as quantitative aspects of the 2D spectrum are found to be in good agreement with recent molecular dynamics calculations. The most important singular feature is the relatively strong rephasing signal observed(More)
A full molecular dynamics (MD) simulation approach to calculate multidimensional third-order infrared (IR) signals of molecular vibrational modes is proposed. Third-order IR spectroscopy involves three-time intervals between three excitation and one probe pulses. The nonequilibrium MD (NEMD) simulation allows us to calculate molecular dipoles from(More)
Thermophilic rhodopsin (TR) is a photoreceptor protein with an extremely high thermal stability and the first characterized light-driven electrogenic proton pump derived from the extreme thermophile Thermus thermophilus JL-18. In this study, we confirmed its high thermal stability compared with other microbial rhodopsins and also report the potential(More)
Adenosquamous cell carcinoma is characterized by both squamous and glandular components, and is a rare disease of the liver that is the subject of few reports in the literature. We present a case in which the imaging findings on CT, MRI, and hepatic arteriography, as well as pathological correlation of the tumor and the clinical history, aided in including(More)
BACKGROUND/AIMS More than 20% of patients with advanced gastric cancer show paraaortic lymph node metastasis. However, whether extensive paraaortic lymphadenectomy is beneficial remains controversial. We performed a prospective study of paraaortic lymphadenectomy for patients with advanced gastric cancer. METHODOLOGY From January 1991 to March 2004, 244(More)
OBJECTIVE To investigate the clinicopathological characteristics of advanced colorectal cancer which was 30 mm or smaller in diameter. METHODS Retrospective analysis documented 80 patients with small advanced colorectal cancer from May 1985 to May 2002. According to the diameter of tumors, all patients were divided into three groups: Group A (10 mm or(More)