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Prehistoric populations suffered the rigors of everyday survival as hunter-gatherers, and some of the individuals had osseous manifestations as a result both of these stresses and of aging. Paleomedical scientists usually seek out osseous abnormalities found in skeletal remains, thus stressing the morbidity of a population [4]. In so doing, they portray those populations as less healthy than their own. This may not necessarily be the case. Specimens without signs of injury should be considered as evidence of the population's vitality; bones with evidence of injury that has healed during life should be considered as evidence of debility; and bones with evidence of conditions that are occupational in origin should be considered as evidence of social, economic, and ecological environmental conditions [4]. This is more useful than singling out specimens with abnormalities as signs of the population's morbidity [4]. This is confirmed by the majority of bones appearing osteologically healthy, except for the characteristic findings of biomechanical wear and tear arising from acquiring food and from combat (osteoarthritis, fractures). Although a number of children may have been infected by the treponematoses, which were manifested by cutaneous lesions, only a small percentage of children actually experienced osseous infection. Also, bone metastases were extremely rare. 相似文献
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El-Antably A. Edwards J. Williams G. Lindon P. Luke P. 《IEEE transactions on magnetics》1979,15(6):1440-1442
Theoretical and experimental results are presented for the performance of a linear reluctance motor with a ratio of airgap to pole pitch appropriate for urban transport applications. Results are given for conditions of constant current, voltage, flux or normal force; it is shown that the machine could be used for combined propulsion and magnetic suspension of a vehicle. 相似文献
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Au nanoparticles have distinctive absorption spectra whose peak position or particle plasmon resonance wavelength is highly sensitive to molecule adsorption on their surfaces. Spherical Au nanoparticles are surface-modified by amino-functionalized self-assembly-monolayer and used as optical probes in the fluorescence-label-free spectroscopic detection of sub-nanomole oligonucleotides. Time-resolved studies of the immobilization and hybridization of oligonucleotides on the surface of Au nanoparticles were carried out. By measuring peak shift of absorption spectra of the Au colloidal nanoparticles over time, the samples of 15 nM 20 mer target and mismatched oligonucleotides are distinguished by their different influences on the particle plasmon resonance wavelength. The approach presented in this paper extends the application of Au nanoparticles as the optical probe in oligonucleotide recognitions without prior sample labeling. 相似文献
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Johnson SM Wiseman RL Sekijima Y Green NS Adamski-Werner SL Kelly JW 《Accounts of chemical research》2005,38(12):911-921
Small molecule-mediated protein stabilization inside or outside of the cell is a promising strategy to treat protein misfolding/misassembly diseases. Herein we focus on the transthyretin (TTR) amyloidoses and demonstrate that preferential ligand binding to and stabilization of the native state over the dissociative transition state raises the kinetic barrier of dissociation (rate-limiting for amyloidogenesis), slowing and in many cases preventing TTR amyloid fibril formation. Since T119M-TTR subunit incorporation into tetramers otherwise composed of disease-associated subunits also imparts kinetic stability on the tetramer and ameliorates amyloidosis in humans, it is likely that small molecule-mediated native state kinetic stabilization will also alleviate TTR amyloidoses. 相似文献
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