The prediction performance of the automatic threshold estimation of photoelectron yield spectroscopy using machine learning and least squares regression (fitting) was verified using 82 measured data. The correct answer rate was greater than 80% for machine learning and less than 50% for fitting, within an error range of ±0.3 eV with respect to the correct answer (the result of human spectrum analysis). To further improve the correct answer rate, it is necessary to change the energy range and energy step of the measured data because increase in the nonlinear intensity at the high-energy side of the spectrum is considered to affect the automatic estimation. The estimation did not change with changes in the energy step of the data. However, when the energy range in the data was changed, the estimation improved. If the threshold is expected to be less than 6.0 eV, the prediction is improved by using an energy range of 4.2–6.2 eV.
Microscopic studies on electrolyte solution / electrode interfaces provide the most fundamental information not only for understanding the electric double layer formed at the interfaces but also for designing sophisticated electrochemical (EC) devices. In this study, we developed tip-enhanced Raman spectroscopy (TERS), which is based on an electrochemical scanning tunneling microscope (EC-STM), and demonstrated electrochemical TERS (EC-TERS) measurements of benzenethiol monolayers on Au(111). A specially-designed cell enables us to carry out reproducible EC, EC-STM, and EC-TERS measurements, which indicates consistent results among these techniques for the oxidative desorption of the benzenethiol monolayers.
This paper describes the newly developed two magnetron sputtering cathodes with a magnetic mirror configuration for a low gas and power operation and an inward enlargement of the doughnut-shaped plasma discharge area. These cathodes were named Magnetic Mirror-type Magnetron Cathode (M3C). Those magnetic field profiles have a simple structure using two cylindrical permanent magnets placed behind the disk-shaped sputtering target. In the case of M3C ver.1 (M3C1), the magnetic mirror configuration near the target center and the target edges enables a low DC input power operation down to 5 W at 0.26 Pa (Ar). In the case of M3C ver.2 (M3C2), both a pinhole-centered magnet and a tilt of magnetization vector to the normal to the target surface play an important role for the inward enlargement of the plasma discharge area.
Biomolecules interact with their target molecules accurately in crowded conditions in cells or bodies with rarely making mistakes (non-specific binding). In this review, we discuss the mechanism underlying the accuracy in the molecular recognition of biomolecules, in particular, the suppression of non-specific interactions. Our surface force measurements revealed that water-mediated force critically governs the colloidal stability of Au nanoparticles covered with DNA molecules. The colloidal stability depended on the complementarity of the terminal base pairs. In the case of the peptide molecules, the SAMs of peptide that contains zwitterionic pairs of glutamic acids and lysines exhibited excellent anti-fouling properties, whereas the SAMs of peptide that possesses glutamic acids and arginines did not. We also found that interfacial water plays an essential role as a barrier preventing the approach of proteins and cells. From these findings, we are noticing that biomolecules smartly use their interfacial water to accomplish their specific interactions.
Recently it has become possible for SEM to obtain a backscattered electron image (BEI) at low incident voltages of 1 kV or less. However, it was reported that some brightness in the BEI acquired at low incident voltages was not always proportional to the average atomic number of the sample. In this study, we investigated contrast reversal phenomena of two elements (C and Au) in BEIs using backscattered electrons acquired by Auger electron spectroscopy (AES) at an incident voltage of about 1 kV.
Mechanical properties of scaffolds have recently been found to impose strong impact on the behavior of cultured cells. Here, we focused on the effect of scaffold's elastic modulus on the development of synaptic connections in cultured neurons, and developed a novel system for culturing rat cortical neurons on an ultrasolft gel surface with an elastic modulus resembling the brain.
The characteristics of the gas flow changes depending on the diameter and the length of the cylindrical tube, pressure, gas spices, and temperature. There are at least six flow regimes to explain the characteristics of the gas flow, such as molecular flow (also called free molecular flow) ; continuum flow including viscous laminar flow, turbulent flow, critical flow (sonic flow or choked flow), and subcritical flow (subsonic flow or non-choked flow) ; and their intermediates (intermediate flow, transition flow, or slip flow). This review paper summarized equations to calculate the gas flow rate through a cylindrical tube for each flow regime.