Effect of shear stress on hepatocyte viability under horizontal and vertical syringe orientation
Improving cell viability and function are important for enhancing the clinical results of cell transplantation. The relationship between cell viability and shear stress remains unexplained, and sedimentation effects during the infusion process are important to the hepatocyte transplantation process. In the present study, the relationship between cell viability and shear stress in the presence of sedimentation effect was investigated using a microchannel simulating the cell transplantation process under several shear stress conditions. Horizontal and vertical syringe orientations were employed to investigate the sedimentation effect. The vertical syringe orientation resulted in lower viability loss than the horizontal orientation. In summary, removing a sedimentation effect is important to improving cell viability by preventing high shear stress.
We present first-principles studies on how to engineer band lineups of nanosized radial heterojunctions, Si/Ge core-shell nanowires. Our calculation reveals that band offsets of these one-dimensional nanostructures can be tailored by applying the axial strain. In particular, the valence band offset can be efficiently tuned in a wide range and even be diminished with applied strain. Two mechanisms contributing to this strain engineering of band offsets are discussed. Our proposed approach to control band offsets in nanosized heterojunctions may be of practical interest for nanoelectronics and photovoltaic applications.