Axial and nonaxial migration of red blood cells in a microtube

Human red blood cells (RBCs) are subjected to high viscous shear stress, especially during microcirculation, resulting in stable deformed shapes such as parachute or slipper shape. Those unique deformed RBC shapes, accompanied with axial or nonaxial migration, cannot be fully described according to traditional knowledge about lateral movement of deformable spherical particles. Although several experimental and numerical studies have investigated RBC behavior in microchannels with similar diameters as RBCs, the detailed mechanical characteristics of RBC lateral movement—in particular, regarding the relationship between stable deformed shapes, equilibrium radial RBC position, and membrane load—has not yet been fully described. Thus, we numerically investigated the behavior of single RBCs with radii of 4 µm in a circular microchannel with diameters of 15 µm. Flow was assumed to be almost inertialess. The problem was characterized by the capillary number, which is the ratio between fluid viscous force and membrane elastic force. The power (or energy dissipation) associated with membrane deformations was introduced to quantify the state of membrane loads. Simulations were performed with different capillary numbers, viscosity ratios of the internal to external fluids of RBCs, and initial RBC centroid positions. Our numerical results demonstrated that axial or nonaxial migration of RBC depended on the stable deformed RBC shapes, and the equilibrium radial position of the RBC centroid correlated well with energy expenditure associated with membrane deformations.Takeishi N, Yamashita H, Omori T, Yokoyama N, Sugihara-Seki M. Axial and Nonaxial Migration of Red Blood Cells in a Microtube. Micromachines. 2021; 12(10):1162. https://doi.org/10.3390/mi1210116

Improved Path Planning of the Blade for an Automatic Spinach Harvester

ArticleIFAC-PapersOnLine. 53(2): 15816-15823. (2020)journal articl

Synthesis of Stable Isotope Labeled Lactosamine

講演番号：4 G4 14　日本化学会第69春季年会, 平成7年3月27日～3月30日, 京

Tl-201大量投与Single photon emission computed tomographyによる肺癌診断の試み

金沢大学大学院医学系研究

Upper abdominal body shape is the risk factor for postoperative pancreatic fistula after splenectomy for advanced gastric cancer: A retrospective study

<p>Abstract</p> <p>Background</p> <p>Postoperative pancreas fistula (POPF) is a major complication after total gastrectomy with splenectomy. We retrospectively studied the effects of upper abdominal shape on the development of POPF after gastrectomy.</p> <p>Methods</p> <p>Fifty patients who underwent total gastrectomy with splenectomy were studied. The maximum vertical distance measured by computed tomography (CT) between the anterior abdominal skin and the back skin (U-APD) and the maximum horizontal distance of a plane at a right angle to U-APD (U-TD) were measured at the umbilicus. The distance between the anterior abdominal skin and the root of the celiac artery (CAD) and the distance of a horizontal plane at a right angle to CAD (CATD) were measured at the root of the celiac artery. The CA depth ratio (CAD/CATD) was calculated.</p> <p>Results</p> <p>POPF occurred in 7 patients (14.0%) and was associated with a higher BMI, longer CAD, and higher CA depth ratio. However, CATD, U-APD, and U-TD did not differ significantly between patients with and those without POPF. Logistic-regression analysis revealed that a high BMI (≥25) and a high CA depth ratio (≥0.370) independently predicted the occurrence of POPF (odds ratio = 19.007, p = 0.002; odds ratio = 13.656, p = 0.038, respectively).</p> <p>Conclusion</p> <p>Surgical procedures such as total gastrectomy with splenectomy should be very carefully executed in obese patients or patients with a deep abdominal cavity to decrease the risk of postoperative pancreatic fistula. BMI and body shape can predict the risk of POPF simply by CT.</p