The aggregation and dispersion structures of surface-modified nanoparticles in a solvent were visualized and analyzed using numerical simulations based on the discrete element method that takes into account the interaction between the surface-modifier and organic solvent. The interface structure between the surface-modifier and organic solvent was visualized using molecular dynamics simulations. The relationship between the interface structure and their affinity was analyzed.

The purpose of this study is to demonstrate the usefulness of time-domain NMR (TD-NMR) in characterizing the physicochemical properties of pharmaceuticals, particularly solid dosage forms. TD-NMR is a technique specialized in the measurement of ¹H-NMR relaxometry that enables rapid and easy measurement of NMR parameters, including T₁ and T₂ relaxation times. These parameters are closely linked to the molecular mobility of substances; thus, allowing us to investigate the physicochemical properties of samples based on this aspect. With the expectation that TD-NMR would prove to be a powerful tool in pharmaceutical evaluations, our research group has been gathering evidence across various research projects. This article presented two case studies using TD-NMR: one that investigated the crystalline state of active pharmaceutical ingredients (APIs) and another that examined the effect of molecular mobility of hygroscopic water in excipients on the hydrolysis of APIs.

This article aims to showcase recent advancements in aerosol research, focusing on their applications in various fields, from environmental health to infectious disease control. The work presented here stems from our research group’s mission to improve global public health through cutting-edge studies on the effects of ambient air and other environmental media on human health. This article will introduce several key developments, including: a novel method for evaluating the health effects of particulate matter using cyclones and water-soluble filters; techniques for particle measurement in enclosed environments; insights into the charging state of ambient submicron particles; and innovative particle measurement technologies contributing to infectious disease control.

Railway vehicles may experience wheel slip/slide while braking in rainy or snowy conditions. Compressed air and ceramic particles are used and directed toward the wheel-rail contact area to improve wheel adhesion. In this study, bench tests were conducted to determine the effectiveness of continuous and intermittent jetting of ceramic particles. An electrostatic sensor was used to measure the flow rate of the particles. The goal was to identify an efficient method for jetting ceramic particles that minimizes air consumption while maximizing the mass of jetted particles. Additionally, the study derived a conversion coefficient to estimate jetted particle mass based on the time integral of the voltage output from the sensor for practical use.