Human soft tissues, mechanical

SubceUular distribution of Pb in human soft tissues appears to mainly involve the mitochondria and nuclei, two organelles known to either be affected toxicologically by lead or be involved in Pb sequestration and toxicokinetics. Intranuclear inclusion bodies, for example, have long been known to form as a transitory protective mechanism for averting or delaying lead toxicity. Lead in relatively large amounts is sequestered in nuclear inclusions and the biochemical and structural characteristics of these bodies have been described (Carroll et al., 1970 Moore et al., 1973). Cramer et al. (1974) showed the formation of intranuclear inclusions as an early response to Pb in kidney proximal tubule cells in new lead workers. 

PVA hydrogels are non-bio degradable and relatively bio compatible and can be easily fabricated since they possess high stability under a range of temperature and pH conditions [43]. Their structural mechanical properties are similar to those of human soft tissues and provoke a limited inflammatory response [54]. 

Table 8.1 Mechanical properties of selected human soft tissues and tissue components.

In any imaging experiment, the critical issues are sample preparation, image contrast, spatial resolution, field of view, and total time of the experiment Relative to other imaging techniques, the NMR spectroscopists s control over the image contrast mechanisms is exceptional. Of course, MRI images are affected by the number of nuclei in each volume element In addition, the NMR relaxation dynamics, Ti and T2, can be used to control image contrast, especially for the soft tissues in the human body. Sample preparation is perfectly simple for the patient remove metal objects and lie still. For inanimate objects, sample preparation of... 

Tissue Properties. The properties of human tissues when the body is considered a linear, passive mechanical system are summarized in Table 10.1 (von Gierke et al., 2002 Goldstein et al., 1993). The values shown for soft tissues are typical of muscle tissue, while those for bone depend on the structure of the specific bone. Cortical bone is the dominant constituent of the long bones (e.g., femiu, tibia), while trabecular bone, which is more elastic and energy absorbent, is the dominant constituent of the vertebrae. The shear viscosity and bulk elasticity of soft tissue are from a model for the response in vivo of a human thigh to the vibration of a small-diameter piston (von Gierke et al., 1952)... 

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