High-resolution image-based simulation reveals membrane strain concentration on osteocyte processes caused by tethering elements

Osteocytes are vital for regulating bone remodeling by sensing the flow-induced mechanical stimuli applied to their cell processes. In this mechanosensing mechanism, tethering elements (TEs) connecting the osteocyte process with the canalicular wall potentially amplify the strain on the osteocyte processes. The ultrastructure of the osteocyte processes and canaliculi can be visualized at a nanometer scale using high-resolution imaging via ultra-high voltage electron microscopy (UHVEM). Moreover, the irregular shapes of the osteocyte processes and the canaliculi, including the TEs in the canalicular space, should considerably influence the mechanical stimuli applied to the osteocytes. This study aims to characterize the roles of the ultrastructure of osteocyte processes and canaliculi in the mechanism of osteocyte mechanosensing. Thus, we constructed a high-resolution image-based model of an osteocyte process and a canaliculus using UHVEM tomography and investigated the distribution and magnitude of flow-induced local strain on the osteocyte process by performing fluid–structure interaction simulation. The analysis results reveal that local strain concentration in the osteocyte process was induced by a small number of TEs with high tension, which were inclined depending on the irregular shapes of osteocyte processes and canaliculi. Therefore, this study could provide meaningful insights into the effect of ultrastructure of osteocyte processes and canaliculi on the osteocyte mechanosensing mechanism.

Research on nanoprocess of non-equilibrium materials by in situ ultra-high voltage electron microscopy

Ultra-high voltage electron microscopy is useful for research utilizing high-penetration thickness of electron beam, in situ observation, or irradiation effects by the particle characteristics of electrons. In this review, the importance of non-equilibrium materials science research by a combination with irradiation effects and in situ observation is shown, and examples of some research are introduced. For example, crystal-amorphous-crystalline phase transition in intermetallic compounds, non-equilibrium phase transition in pure metallic nanoparticles and nucleation and growth process of electron irradiation-induced crystallization in amorphous nanoparticles will be discussed. Finally, we want to suggest the importance of exploring non-equilibrium materials science based on dynamic structures which has been unexplored.

New crystallography using relativistic femtosecond electron pulses

Ultrafast electron microscopy (UEM) with femtosecond temporal resolution has long been a cherished dream tool for scientists wishing to study ultrafast structural dynamics in materials, appealing to researchers from across a wide range of speciality areas. Associate Professor Jinfeng Yang, from the Institute of Scientific and Industrial Research, at Osaka University in Japan, leads a team working on ultrafast electron diffraction (UED) and ultrafast electron microscopy (UEM) development. 'Through the study of ultrafast phenomena with the UEM, we hope to gain a deeper understanding of materials and their physical properties and achieve a novel breakthrough in materials science,' he highlights. 'We fully expect to facilitate new knowledge and discoveries as a result of our work.' The team's work on relativistic UEM has led to the creation of unprecedented innovative technology that enables femtosecond atomic-scale imaging using just a single shot measurement. This will pave the way for the study of dynamics of irreversible processes within materials sciences. Not only does the group's work represent a huge step forward in innovative technology for researchers working across a number of scientific fields, but it is also progress in developing a very compact, ultra-high voltage electron microscopy. It can also be used in a variety of settings such as general research institutions and laboratories. In addition, through its provision of a solution to the problem of femtosecond temporal resolution our technology is breaking new ground in electronic microscopy developments,' says Yang.