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281.
In future large-scale molecular dynamics (MD) simulations that will use parallel computing, the isotropic periodic sum (IPS) method is expected to effectively reduce the cost of interaction calculations while maintaining adequate accuracy. To assess the accuracy of this method in estimating low-charge-density polymer systems, we performed atomistic MD simulations of the bulk state of liquid crystal systems based on 4-pentyl-4′-cyanobiphenyl (5CB). In conditions of 270 K ≤ T ≤ 320 K and a normal pressure, the temperature dependence of the density, potential energy and order parameter was estimated using the IPS and Ewald sum method. The results of the IPS method and Ewald sum were consistent within the range of error. In conditions close to the phase transition point, however, the averaged values of potential energy and order parameter had a small difference. We concluded that the fundamental physical properties for the bulk state of 5CB systems are determined reasonably by using the IPS method, at least in conditions that are not close to the phase transition point. 相似文献
282.
Journal of Plant Research - Phegopteris decursivepinnata includes diploids, tetraploids, and triploid hybrids based on x = 30. We obtained polyploid progeny from triploid hybrids... 相似文献
283.
Sclerotinia trillii n. sp., which attacksTrillium tschonoskii andT. smallii in Hokkaido and northern Honshu, Japan, is described. The characters identifying this species with the genusSclerotinia are large tuberoid sclerotia, produced both on infected plants and in culture, which consisted of only mycelium (true sclerotia)
and flesh apothecia produced on them. This species is distinguished fromS. sclerotiorum, S. minor, S. trifoliorum, andS. nivalis by relatively large sclerotia, cultural colony appearance, and red-brown to yellow-brown, relatively large apothecium, in
addition to its parasitic nature onTrillium. Sclerotinia trillii is a psychrophilic having an optimum temperature for mycelial growth at 15–20°C. 相似文献
284.
Addition of norepinephrine or isoproterenol to primary cultures started from the brains of 1-3 day old rats caused up to 200-fold increases in cAMP levels, which reached a maximum by 5-10 min and then declined. This effect was studied in detail for norepinephrine. The rise in cAMP levels was followed by morphological changes, in which up to 65% of the cells exhibited an astrocyte-like morphology, and 2-3 fold increases in carbonic anhydrase and (Na+-K+) ATPase activities. However, morphological transformation also occurred after much smaller increases in total cAMP levels. These effects on cell morphology and enzyme activities reached a maximum 1-2 h after addition of norepinephrine and then declined. Carbonic anhydrase activity was found both in the particulate and post 100,000 g supernatant fractions from homogenates of these cultured cells, and in the latter case the activity was activated 3-fold by addition of cAMP. The significance of these obscrvations on the cellular localization of, and functional role for similar increases in cAMP in brain tissue is discussed. 相似文献