Shock compression of silicon polymer foams with a range of initial densities
SHOCK COMPRESSION OF CONDENSED MATTER - 2003, PTS 1 AND 2, PROCEEDINGS
Authors: Alcon, RR; Robbins, DL; Sheffield, SA; Stahl, DB; Fritz, JN
Abstract
We report here on a collection of shock compression experiments on a silicon polymer foam with varying degrees of distension from low (similar to0.4 g/cm(3)) to the near fully dense material (similar to 1 g/cm 3). These experiments are being carried out on a two-stage gas-gun (50 mm bore) with a Kel-F 81 impactor at velocities between 1.5 and 3.1 km/s. Particle and shock velocity measurements are made with magnetic gauges by inserting the gauge package (0.001 inches thick) between layers of 2.3 mm thick foam. Special attention is required for assembly of these targets due to the foam's low strength. To minimize compression and gaps at interfaces, the foams are positioned between support rings, which are machined to match the foam's thickness. The Hugoniot data from these experiments is compared to unpublished data obtained with explosively driven flyers at Los Alamos National Laboratory in the early 1980's.
Molecular matching for patients with haematological diseases expressing altered RHD-RHCE genotypes
VOX SANGUINIS
Authors: Cruz, Bruno Ribeiro; de Souza Silva, Thamy Caroline; Castro, Bianca de Souza; Chiba, Akemi Kuroda; Moritz, Elyse; Braga, Josefina Pellegrini; Figueiredo, Maria Stella; Bordin, Jose O.
Abstract
Background and Objectives The high homology and the inverted orientation of RHD and RHCE may give rise to non-functional and aberrant RH alleles. RH genotyping is used to screen RH matched donors to African descent patients. This study aimed to define a strategy for testing RHD and RHCE variants in blood donors to provide compatible units for transfusion of patients with haematological diseases. Materials and Methods Samples from 132 patients [101 Sickle cell disease (SCD), 14 myelodysplastic syndrome (MDS), 17 acute myelogenous leukaemia (AML)] and 198 Brazilian donors were studied. Major blood group alleles, RHD, RHCE alleles and RHD zygosity were determined by the blood-MLPA assay. Sequencing was performed to determine RHD and RHCE variant subtypes. A match was an RH genotype that did not encode Rh antigens absent in the patient, along with matching for ABO, MNS, KEL, FY, JK and DI antigens. Results Overall, 7 center dot 6% of blood donors and 17.4% of patients presented RH genotypes that predict expression of partial Rh antigens or lack of high prevalence Rh antigens. From 23 patients with clinically relevant RH genotypes, 15 had available matched donors. Conclusion We report the presence of clinically relevant RH genotypes in SCD and in non-SCD patients. In our admixed population, many patients carry variant RHCE alleles in heterozygosity with normal RHCE alleles. Thus, our results suggest that donors could be selected based on the normal RH allele.