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论文类型：期刊论文

发表时间：2016-09-01

发表刊物：JOURNAL OF APPLIED MECHANICS-TRANSACTIONS OF THE ASME

收录刊物：SCIE、EI、Scopus

卷号：83

期号：9

ISSN号：0021-8936

关键字：brain stem; viscoelasticity; differential scanning calorimetry; Fourier transform infrared spectrometer spectra; compression

摘要：The stress-strain curves of brain stem in uniaxial compression demonstrate strain rate dependency and can be characterized with three regions: initial toe region, transitional region, and high strain region, suggesting strong viscoelastic behavior. To investigate the origin of this viscoelasticity at microscale, differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectra of brain stem tissue were recorded and analyzed. The emergence of endotherm thermal domains in DSC indicates that the conformation change of biomolecules can absorb and dissipate energy, explaining the viscous behavior of the brain stem. FTIR analyses indicate that the presence of polar functional groups such as amide, phosphate, and carboxyl groups in the biomolecules takes responsibility for the viscous performance of brain stem. Ogden, Fung, and Gent models were adopted to fit the experimental data, and Ogden model is the most apt one in capturing the stiffening of the brain stem with the increasing strain rate.