COMBINED EFFECT OF LINEAR AND NON-LINEAR TRANSPORT RATES ON SOLUTE UPTAKE INTO BIOLOGICAL TISSUES

1979 ◽  
pp. 429-430
Author(s):  
J.J. OERTLI
1999 ◽  
Vol 202 (23) ◽  
pp. 3305-3313 ◽  
Author(s):  
R.E. Shadwick

The most important mechanical property of the artery wall is its non-linear elasticity. Over the last century, this has been well-documented in vessels in many animals, from humans to lobsters. Arteries must be distensible to provide capacitance and pulse-smoothing in the circulation, but they must also be stable to inflation over a range of pressure. These mechanical requirements are met by strain-dependent increases in the elastic modulus of the vascular wall, manifest by a J-shaped stress-strain curve, as typically exhibited by other soft biological tissues. All vertebrates and invertebrates with closed circulatory systems have arteries with this non-linear behaviour, but specific tissue properties vary to give correct function for the physiological pressure range of each species. In all cases, the non-linear elasticity is a product of the parallel arrangement of rubbery and stiff connective tissue elements in the artery wall, and differences in composition and tissue architecture can account for the observed variations in mechanical properties. This phenomenon is most pronounced in large whales, in which very high compliance in the aortic arch and exceptionally low compliance in the descending aorta occur, and is correlated with specific modifications in the arterial structure.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Oliver Pabst ◽  
Ørjan G. Martinsen ◽  
Leon Chua

AbstractMuch is already understood about the anatomical and physiological mechanisms behind the linear, electrical properties of biological tissues. Studying the non-linear electrical properties, however, opens up for the influence from other processes that are driven by the electric field or movement of charges. An electrical measurement that is affected by the applied electrical stimulus is non-linear and reveals the non-linear electrical properties of the underlying (biological) tissue; if it is done with an alternating current (AC) stimulus, the corresponding voltage current plot may exhibit a pinched hysteresis loop which is the fingerprint of a memristor. It has been shown that human skin and other biological tissues are memristors. Here we performed non-linear electrical measurements on human skin with applied direct current (DC) voltage pulses. By doing so, we found that human skin exhibits non-volatile memory and that analogue information can actually be stored inside the skin at least for three minutes. As demonstrated before, human skin actually contains two different memristor types, one that originates from the sweat ducts and one that is based on thermal changes of the surrounding tissue, the stratum corneum; and information storage is possible in both. Finally, assuming that different physiological conditions of the skin can explain the variations in current responses that we observed among the subjects, it follows that non-linear recordings with DC pulses may find use in sensor applications.


1994 ◽  
Vol 26 (6) ◽  
pp. 467-472 ◽  
Author(s):  
D Weinmann ◽  
W Häusler ◽  
W Pfaff ◽  
B Kramer ◽  
U Weiss

1987 ◽  
Vol 62 (7) ◽  
pp. 503-507
Author(s):  
O Valassiades ◽  
E Pavlidou ◽  
N.A Economou

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