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CoCrNi medium-entropy alloy has superior cryogenic properties with simultaneous growth of strength and plasticity at low temperatures. In order to observe the microstructure and deformation behavior of the alloy at the atomic scale, its mechanical properties and deformation mechanism at different temperatures and strain rates were investigated using molecular dynamics. It is indicated that the alloy's strength was enhanced at low temperatures and high strain rates due to the production of high dislocation density. The introduction of grain boundaries significantly decreased the dislocation density during the alloy's deformation and correspondingly reduced the crystal strength. However, the introduction of twin boundaries in polycrystalline grains obviously enhanced the strength of the polycrystal, especially at the twin boundary spacing of 3.08 nm. The strength's enhancement was attributed to the increasing dislocation density produced by the interaction between twin boundaries and dislocations during deformation. [ABSTRACT FROM AUTHOR]

Background: The purpose of the current study was to determine whether the use of hematopoietic stem cell transplantation (HCT) to treat leukemia, lymphoma, or multiple myeloma (MM) differs by race and sex.Methods: The annual incidence of leukemia, lymphoma, and MM was estimated in the United States in people aged <70 years by race and sex using the Surveillance, Epidemiology, and End Results (SEER) cancer registry between 1997 and 2002 and US census reports for the year 2000. The annual incidence of autologous, human leukocyte antigen (HLA) identical sibling, and unrelated HCT performed in these groups was estimated using Center for International Blood and Marrow Transplant Research data from 1997 through 2002. Logistic regression analysis was used to calculate the age-adjusted odds ratio (OR) of receiving HCT for Caucasians versus African Americans and for men versus women.Results: The likelihood of undergoing HCT was found to be higher for Caucasians than for African Americans (OR, 1.40; 95% confidence interval [95% CI], 1.34-1.46). This difference existed for each type of HCT: autologous (OR, 1.24; 95% CI, 1.19-1.30), HLA identical sibling (OR, 1.59; 95% CI, 1.46-1.74), and unrelated donor (OR, 2.02; 95% CI, 1.75-2.33). Overall, men were more likely than women to receive HCT (OR, 1.07; 95% CI, 1.05-1.1 [P<.0001]); however, this difference was found to be significant only for autologous HCT (OR, 1.10; 95% CI, 1.07-1.13 [P<.0001]).Conclusions: HCT is more frequently used to treat leukemia, lymphoma, and MM in Caucasians than in African American individuals. African Americans have lower rates of both autologous and allogeneic HCT, indicating that donor availability cannot fully explain the differences. Women are less likely than men to receive autologous HCT for reasons unexplained by age or disease status. [ABSTRACT FROM AUTHOR]