The Arabidopsis thaliana ACT4/ACT12 actin gene subclass is strongly expressed throughout pollen development

We analyzed the displacement activity of sarpogrelate and its active metabolite (M-1) in the radiolabeled ligand binding to various 5-hydroxytryptamine (5-HT) receptor subtypes using rat brain cortical membranes. Sarpogrelate was shown to have the same affinity as ritanserin for 5-HT2A receptors, with a Ki value of 8.39 nM. The active metabolite of sarpogrelate, M-1, was more active than sarpogrelate itself and of ritanserin, with a Ki value of 1.70 nM. Both sarpogrelate and M-1 had no affinity for 5-HT1A receptors, but these substances, at a concentration of 10 microM, displaced the specific binding to the 5-HT1B receptors of [125I]iodocyanopindolol, resulting in Ki values of 0.881 and 0.859 microM, respectively. The Ki values of sarpogrelate and M-1 are almost the same as that of ritanserin, a specific 5-HT2 receptor antagonist. Sarpogrelate and M-1, as well as ritanserin, are shown to have very low affinity for 5-HT1B receptors. Both sarpogrelate and M-1 had no affinity for 5-HT3 receptor subtypes. In the 5-HT4 receptor binding experiments, sarpogrelate exhibited almost no affinity, while M-1, at the concentration of 10 microM, displaced the binding activity, resulting in a Ki value of 0.838 microM. Both drugs had a weak antagonistic effect on a 5-HT4 receptor-mediated function, i.e., the 5-HT-induced relaxation of rat isolated esophageal tunica muscularis mucosae. In conclusion, sarpogrelate and M-1 have high affinity for 5-HT2A receptors with a relatively high selectivity.     

Effects of Expanded Polytetrafluoroethylene as a Packaging Material on the Appearance and Texture of Microwave-Baked Soy Cookies

The feasibility of expanded polytetrafluoroethylene (ePTFE) as a packaging material for microwave-baked soy cookies was investigated in comparison with polytetrafluoroethylene (PTFE) and a susceptor incorporating elemental-metal into a receptacle (EMIR). Physical properties such as the dimensions, color, hardness, and the specific gravity of the products were measured. Soy cookies enclosed in ePTFE showed golden brown color evenly distributed with textural measurements compatible to regular chocolate chip cookies. Soy cookies microwaved in PTFE and EMIR yielded inferior physical attributes. ePTFE was capable of adequately retaining the moisture of soy cookies, indicating the potential as a packaging material for microwavable dough-based products.     

Fretting of Hardened Steel in Oil

To determine the effect of hardness on fretting wear, tests of AISI 4340 steel were made in an oil bath using a new machine designed to make fretting corrosion tests with a wide range of parameters. Hardness values from 258 to 743 Vickers were tested, the hardest specimen having a nitrided surface. The fretting action used, 0.005 in. reciprocating motion at pressures from 430 psi to 5840 psi, produced much less fretting than similar tests in air, with little or no oxide products resulting. The galled areas were measured for depth of pit and height of deposit with the results indicating some small effects due to hardness up to 460 Vickers. The nitrided specimens, however, produced smaller fretted areas and the roughening of their surfaces was shallow.     

Discrete element modelling of uniaxial constant strain rate tests on asphalt mixtures

Constant strain rate tests for a graded asphalt mixture under three constant strain rates have been undertaken in the laboratory. The Discrete Element Model has been used to simulate the laboratory tests with a numerical sample preparation procedure being developed to represent the physical specimen. The Burger’s model has been used to represent the time dependent behavior of the asphalt mixture. The Burger’s model was implemented to give bending and torsional resistance as well as in direct tension and compression. The stress-strain response for the laboratory tests and the simulations under three loading speeds were recorded. The results show reasonable agreement when the bond strengths in the model are made to be a function of strain rate. Both normal and Weibull distributions have been used for the bond strengths between the aggregate particles. The effects on the stress-strain response of bond strength variability and particle position are proved to be negligible. Bond breakage was recorded during the simulations to explain the internal damage within the sample. The modified Burger’s model has proved to be a useful tool in modeling the bending and torsional resistance at particle contacts in an asphalt mixture, in order to correctly predict observed behavior.     

A concurrent scheme for passing dislocations from atomistic to continuum domains

This paper presents a concurrent atomistic-continuum (CAC) methodology for three-dimensional dynamic simulation of dislocation nucleation, migration and interaction. The method is based on a new continuum field formulation of balance laws with relevant atomistic information (the arrangements and interactions of atoms) considered. In this work, we show that the new CAC method allows the smooth passage of dislocations through sharp interfaces between the atomistic and the coarse-grained finite element domains without unphysical reflection of dislocations or the need for heuristic rules; meanwhile, complex dislocation phenomena such as dislocation nucleation, dynamic strain bursts associated with nucleation and migration avalanches, formations of Lomer-Cottrell locks, dislocation-rigid boundary interactions, formation of intrinsic and extrinsic stacking faults, deformation twinning, and curved dislocation loops can be reproduced by the CAC method. All of the CAC simulations are directly compared with the corresponding atomic-level molecular dynamics (MD) simulations. The efficiency, accuracy and potential applications of the method are discussed along with necessary additional development of criteria for coarse graining.     

Size effects and strength fluctuation in nanoscale plasticity

Stochastic, discontinuous flow is ubiquitous in the plastic deformation of small-volume metallic materials. We have identified a size-strengthening effect on the stress to initiate the jerky plastic yielding in nanoscale volumes of copper single crystals, subjected to nanoindentation in different orientations. Such a nanoscale size effect arises due to the stochastic nature of dislocation sources, in contrast to the microscale size effect often attributed to plastic strain gradients. The jerky response can result from the activation of either surface or bulk heterogeneous dislocation sources, as governed by the distribution and resistance of dislocation locks. Implications concerning the deformation mechanism in materials with flow defect-limited characteristics are discussed.     

Physical characteristics of lamb primals packaged under vacuum or modified atmospheres

Lamb primals (shoulders) were packaged under vacuum, 80% O(2)/20% CO(2), 50% CO(2)/50% N(2) or 100% CO(2) and stored at 5 or 0 °C. Pack contents were examined at 7 day intervals to determine the composition of the pack atmosphere, drip loss, colour (muscle and fat) and pH (surface and internal). The composition of the gas atmospheres changed very little during storage. The only significant differences between developed head space compositions above primals stored at the two different temperatures (5 and 0 °C) were noted in packs stored for 28 days under 80% O(2)/20% CO(2). Low levels of drip loss (<0.5%) were noted in all packs stored under the modified gas atmospheres. In contrast, significantly higher levels of drip loss (0.5-1.1%) were noted in vacuum packaged lamb stored at 5 and 0 °C. Acceptable muscle colour was observed 2 hr after opening of all packs. The only significant differences between atmospheres for lean muscle colour were noted after 28 days storage. Fat colour did not generally change during storage in any of the atmospheres, apart from a slight bleaching effect at 7 days. There were no significant differences between the surface or internal pH values noted after storage under any of the atmosphere/temperature combinations. In general, higher pH values were observed at the surface of the meat than in the interior. This pattern was noted before and after storage.