China
Africa
Explore chapters and articles related to this topic
Radionuclide Examination of the Kidneys
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
After intravenous injection, radiopharmaceutical is mixed with the blood, excreted by the kidneys, and simultaneously transported from blood vessels (capillaries) into extravascular space in the body by diffusion. Diffusion lasts until the tracer concentrations in extravascular and intravascular spaces reach transient equilibrium. With GFR tracers and normal kidney function it takes about two hours. The lower the kidney function and the bigger the extravascular space, the longer the time to transient equilibrium.
Dictionary
Published in Mario P. Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990
Transient equilibrium. If the half-life of the parent is sufficiently short, so that the quantity present decreases appreciably during the period under consideration, but is still longer than that of successive members of the series, a stage of equilibrium will be reached after which all members of the series decrease in amount exponentially with the period of the parent.
Nonlinear dynamics of membrane skeleton in osteocyte
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Zhuang Han, Lian-Wen Sun, Xin-Tong Wu, Xiao Yang, Yu-Bo Fan
The response of membrane skeleton to external vibration is nonlinear and it is extremely sensitive to the vibration conditions such as viscosity of spectrin and the frequency of excitation. Under the vibration stimulation of 15 Hz, 30 Hz, 60 Hz, and 90 Hz, the membrane skeleton is destroyed after a transient equilibrium position vibration. The vibration of 15 Hz has the most destructive effect on the membrane skeleton; the natural frequency of membrane skeleton may be less than 15 Hz. In addition, the chaos phenomenon occurs to the membrane skeleton during vibration, and as a damping factor the existence of viscosity alleviates the damage of structure. The dynamic equilibrium of depolymerization and polymerization of membrane skeleton can be changed by external excitation; meanwhile, the structural change of spectrin also affects the mechanosensation and conduction of osteocytes.