12/21/2023 0 Comments The plane effectHowever, acquiring and testing fresh human spinal cord tissue is quite difficult. Knowing this, there is a need to better understand the sensitivity of spinal cord injury mechanics to variations in tissue behavior. Mechanical characterization of neural tissue has shown that tissue mechanical properties vary with age (Prange and Margulies, 2002) and disease affects tissue structures (Lovas et al., 2000 Bot et al., 2004). The expanding aging population and recent reported increases in the numbers of elderly spinal cord injury patients (Jackson et al., 2004), however, motivate a need for improved understanding of the influence of age on injury susceptibility. I t is well established that the severity of damage resulting from spinal cord injury is strongly influenced by the mechanics of the impact (Anderson, 1985 Noyes, 1987 Kearney et al., 1988 Bresnahan et al., 1991 Behrmann et al., 1992 Basso et al., 1996 Gruner et al., 1996). Our results suggest that the mechanics of spinal cord compression are likely to be affected by changes in tissue resulting from aging and disease, indicating a need to study the biomechanical aspects of spinal cord injury in these specific populations. Pressure measurements in both the grey and white matter were particularly sensitive to white matter properties, suggesting that degenerative changes in white matter may influence perfusion in a compressed spinal cord. Using linear elastic models to represent non-linear behavior had variable effects on outcome measures, and resulted in highly concentrated areas of elevated stresses and strains. The pia mater characteristics had limited (<4% change) effects on outcomes. Strain outcome measures were less sensitive (7–27% change) than stresses (74–244% change) to variations in material tangent modulus. In general, principal stresses (114–244% change) and pressure (75–119% change) were the outcomes most sensitive to material variation. Outcome measures were evaluated for percent change in magnitude and alterations in spatial distribution. The material models and stiffness responses for the grey and white matter and pia mater were varied across a range of reported values to observe the sensitivity of model outcomes to the assigned properties. To address this issue, a plane-strain, geometrically nonlinear, finite element model of a section of a generic human thoracic spinal cord was constructed to model the response to dorsal compression. Knowing that age and disease affect neurological tissue, there is a need to better understand the sensitivity of spinal cord injury mechanics to variations in tissue behavior. Based on series of catalytic investigations, the catalytic performance in liquid-phase hydrogenation was intrinsically relevant to the crystal plane effect and reduced Cu proportion induced by an appropriate SMSI effect, which was completely different from gas-phase hydrogenation.Recent demographics demonstrate an increase in the number of elderly spinal cord injury patients, motivating the desire for a better understanding of age effects on injury susceptibility. As a result, the Cu/CeO 2-P catalyst showed the best catalytic performance among three types of catalysts. Furthermore, the degree of the interaction showed great influence on the chemical state of Cu species, and the ratio of (Cu ++Cu 0)/Cu 2+ in Cu/CeO 2-P was higher than Cu/CeO 2-R (Cu loaded on nano-rod CeO 2 with (1 1 0) plane) and Cu/CeO 2-C (Cu loaded on nano-cube CeO 2 with (1 0 0) facet). It was found that Cu was highly dispersed on the external surface of ceria in the Cu/CeO 2-P catalyst via a moderate SMSI effect. In this work, Cu/CeO 2-P (copper loaded on nano-polyhedral CeO 2 with (1 1 1) terminated surface) was investigated its catalytic performance on liquid-phase hydrogenation and studied the SMSI effect by comparing with the catalysts supported on nano-rod and nano-cube CeO 2. Almost all the studies on the SMSI effect of ceria-supported metal catalysts are involved generally in gas-phase reaction, but rarely in the liquid-phase reaction system. Ceria has been widely used as catalyst support displaying a size- or shape-dependent catalytic performance due to the strong metal-support interaction (SMSI) effect with active metal.
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