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Material Properties for Biomedical Applications
Published in Savaş Kaya, Sasikumar Yesudass, Srinivasan Arthanari, Sivakumar Bose, Goncagül Serdaroğlu, Materials Development and Processing for Biomedical Applications, 2022
D. Ajith, K.G. Ashok, K. Aravind
Therefore, corrosion in biomaterials is also attributed by chemical or electrochemical degradation of a material through interactions with its environment. Galvanic corrosion occurs when two dissimilar materials are present in a solution and one becomes cathode and the other becomes anode and the electrons will move from one to another causing the dissolution of the metal. Relative micromotion between two mating surfaces causes fretting corrosion. For example, SS 316L is also prone to wear and various corrosions such as crevice corrosion, intergranular corrosion, pitting corrosion, and fretting corrosion. Other widely used implants, Co-Cr alloys, are subjected to inter-granular corrosion, etching, selective dissolution of cobalt, etc. The corrosion behavior of various biomaterials including metals, metallic glasses, and biodegradable metals are comprehensively discussed in [31]. Implant failure mechanisms, retrieval and failure analysis are highlighted in that study. Table 3.4 shows the concentration of ions in blood plasma extracellular fluid and is compared with Ringer’s solution.
Regulation of Blood Glucose
Published in Robert B. Northrop, Endogenous and Exogenous Regulation and Control of Physiological Systems, 2020
This is considered to be good evidence for a three-compartment pharmacokinetic model for insulin; the three compartments are probably the blood (plasma), the extracellular fluid, and the liver cell volume. The fast phase of insulin decay is seen to take about 20 min for the concentration to go from an initial 400 μU/ml to 20 μU/ml.124
Self-Adjoint Operators
Published in James K. Peterson, Basic Analysis III, 2020
The potential difference across the inner membrane is essentially due to a balance between the electromotive force generated by charge imbalance, the driving force generated by charge concentration differences in various ions and osmotic pressures that arise from concentration differences in water molecules on either side of the membrane. Roughly speaking, the ions of importance in our simplified model are the potassium K+, sodium Na+ and chloride Cl− ions. The equilibrium potential across the inner membrane is about −70 millivolts and when the membrane potential is driven above this rest value, we say the membrane is depolarized and when it is driven below the rest potential, we say the membrane is hyperpolarized. The axon of one neuron interacts with the dendrite of another neuron via a site called a synapse. The synapse is physically separated into two parts: the presynaptic side (the side the axon is on) and the postsynaptic side (the side the dendrite is on). There is an actual physical gap, the synaptic cleft, between the two parts of the synapse. This cleft is filled with extracellular fluid.
Features extraction of MRI image using complex network with low computational complexity to distinguish inflammatory lesions from tumors in the human brain
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2023
Trong Thanh Han, Tung Nguyen Duy, Lam Nguyen Dang Son, Hinh Nguyen Van, Tuan Do Trong, Dung Nguyen Viet, Dung Nguyen Tuan, Luu Vu Dang
Diffusion – Weighted Imaging (DWI) as in Figure 2 is used to evaluate the diffusion of water molecules within an organ. Normally, extracellular fluid diffuses freely in all directions (no diffusion restriction), while intracellular fluid is diffusion restricted. Newly damaged areas cause cellular oedema, resulting in less extracellular fluid, increased intracellular fluid, causing limited diffusion of water. If a structure is diffusely restricted, meaning that there is cellular oedema, the hyperintense DWI image is white. If tissue is not diffusely restricted, there is no cellular oedema, then DWI is hypointense and it is black. Therefore, DWI is a very effective method for detecting cellular swelling (ischaemia, for instance) and oedema. This is one of the typical signs of inflammation.