Abstract: A composite structure comprising a body having a surface. Cladding covers at least a part of the surface. The body and the cladding are formed of different materials, at least one of which is a shape memory alloy having a recoverable strain in excess of 1.0%.

Abstract: Homozygotic cells are obtained by employing homologous recombination with a construct comprising a marker gene. The marker gene allows for selection without amplification and by employing elevated levels of the antibiotic to which the marker gene imparts resistance, gene conversion can occur, where in a diploid host, both copies of the target locus will be the same. In this manner, knock-outs of genes can be readily achieved without requiring two steps of homologous recombination.

Abstract: Expression of mammalian target genes is achieved by employing chromosomal target DNA, either native primary cells or YACs in a yeast host, where the YACs include a fragment of a mammalian chromosome, the fragment comprising the target gene. Employing homologous recombination, an amplifiable gene is integrated into the mammalian fragment at a site to allow for amplification. In the same step, or one or more steps, as desired, the mammalian gene and/or the transcriptional system may be modified by in vivo mutagenesis. The resulting construct from homologous recombination may then be transformed into a mammalian expression host and integrated into the host genome, either randomly or by homologous recombination. The amplifiable gene may then be amplified by an appropriate agent providing for multiple copies of the target gene and the expression host grown to provide for high yields of the desired wild-type or modified protein.

Abstract: Homologous recombination is employed to inactivate genes, particularly genes associated with MHC antigens. Particularly, the .beta..sub.2 -microglobulin gene is inactivated for reducing or eliminating Class I MHC antigens. The resulting cells may be used as universal donors. In addition, embryonic stem cells may be modified by homologous recombination for use in producing chimeric or transgenic mammalian hosts, which may be used as source of universal donor organs, or as models for drug and transplantation therapies.

Abstract: Chimeric proteins and DNA sequence encoding chimeric proteins are provided, where the chimeric proteins are characterized by an extracellular domain capable of binding to a ligand in a non-MHC restricted manner, a transmembrane domain and a cytoplasmic domain capable of activating a signaling pathway. The extracellular domain and cytoplasmic domain are not naturally found together. Binding of ligand to the extracellular domain results in transduction of a signal and activation of a signaling pathway in the cell, whereby the cell may be induced to carry out various functions relating to the signalling pathway. A wide variety of extracellular domains may be employed as receptors, where such domains may be naturally occurring or synthetic. The chimeric DNA sequences may be used to modify lymphocytes as well as hematopoietic stem cells as precursors to a number of important cell types.

Abstract: A reflective metallic foil is modified so that an incident laser beam is diffused into multiple beams to dissipate the energy of the incident beam. The surface can have protrusions that range from 0.3 to 10,000 microns high with an average diameter of from 1 to 1,000 microns and an average spacing between protrusions of from 0.2 to 5,000 microns. The surface of the metallic foil can be provided with a first type pattern consisting of protrusions and indentations having an optimum range of 0.3 to 20 microns deep having average optimum diameter of 2 to 40 microns with an average optimum spacing between protrusions of 1 to 100 microns or a second type pattern consisting of protrusions and indentations having an optimum range of 20 to 100 microns deep having an average optimum diameter of 20 to 100 microns with an average optimum spacing of from 20 to 200 microns. The second type pattern can be superimposed on patterns of the first type.