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The Young's modulus and internal friction of hyperstoichiometric uranium oxide at room temperature were determined by a sonic technique. Young's modulus decreased, whereas internal friction increased, with increasing O/U ratios. These effects are attributed to the precipitation of U4O9. A complete microstructural characterization is needed.  相似文献   
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Solubility tests, turbidity tests, and titration experiments were employed to study the possible protein-protein interactions between purified soybean 11S protein and skeletal muscle myosin and the involvement of protein subunits in the interactions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used as an analytical tool for identification of the protein species. These tests indicate that these proteins interacted at temperatures between 85°C and 100°C. Solubility and titration experiments showed that acidic subunits of soybean US protein had little or no interaction with myosin heavy chain subunits. In contrast, soybean 11S basic subunits interacted with myosin heavy chains. The SDS-PAGE method indicated that eight commercial soy protein isolates had a similar protein species composition, but certain proteins in some isolates had lost their availability for water extraction. This may account for different functional properties exhibited by differen soy protein isolates.  相似文献   
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This article explores the relationship between informal networks of interaction and trust among neighbors and political engagement by neighborhood residents. The United States lacks mass‐based political organizations that directly represent the interests of poor and working class citizens. Therefore, geographically based neighborhood associations are one of the few mechanisms available to represent these interests. The segregation of urban neighborhoods by class and race presents many disadvantages for lower income residents, but geographical concentration can have the advantage of facilitating organized political action. Because neighborhood organizations are such an important mechanism by which disadvantaged urban populations assert their needs and perspectives, it is critical to understand which characteristics of residents encourage the formation of such organizations and enable them to be effective in influencing public policies. What kinds of networks and relationships exist among residents of lower income neighborhoods that might encourage them to organize for political action?  相似文献   
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Beef Longissimus thoracis et lumborum ( LTL ), Semimembranosus (SM) and Biceps femoris (BF) steaks were sonicated using three commercially available ultrasonic baths of different intensities. The effect of ultrasound on the tenderness of these steaks was examined using peak load bite force tenderometry. Collagen solubility and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) analysis were also conducted on samples of BF and LTL exposed to the most intensive of the ultrasound treatments. Peak force values were not affected by ultrasound treatment (P≤ 0.05). Collagen solubility of LTL or BF did not differ (P ≤ 0.05) between ultrasonicated meat and controls. Similarly, SDS PAGE of myofibrillar proteins showed no differences between control and treated samples in the rates of appearance/disappearance of characteristic aging bands or in the numbers of bands observed on the gels suggesting no obvious effect on myofibrillar proteolysis. It is concluded that under the conditions of treatment employed high intensity ultrasound applied to intact beef steaks had no beneficial effect on meat tenderness. This is in contrast to tenderizing effects reported by other workers with more intensive treatments.  相似文献   
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