摘要:
Tissue equivalents are produced by applying a solution of collagen without cells to a permeable membrane, gelling to produce a collagen gel on the membrane, applying a mixture of collagen and a contractile agent to the collagen gel, gelling the mixture and allowing the resultant gel to undergo radial contraction which is controlled by the collagen gel on the membrane. A suitable contractile agent is fibroblast cells. A skin tissue equivalent is produced by disposing human epidermal cells on the contracted collagen gel and allowing epidermalization to occur. A nutrient medium can be supplied to the cells. An absorbent member may be disposed adjacent the permeable membrane opposite the collagen gel on the membrane. The permeable membrane can be the bottom of an inner well disposed in an outer well for containing a nutrient medium in contact with the membrane. The nutrient medium may be contained in the outer well in an agarose gel in contact with the membrane.
摘要:
A computer system includes a main memory that is able to make use of DRAM memory devices having a relatively high level of bad cells (hard faults). An EDC circuit is provided which uses combinatorial logic to perform a BCH code type of error detection and correction. A primary feature is the recognition that due to use of high density integrated circuits--gate arrays--it is no longer necessary to use sequential logic to decode the multiple-bit error correcting codes. An EDC with 128-bits of data and a check bit field 41-bits wide, using a BCH code, constructed in ASIC sea-of-gates technology using about 87,000 logic gates, can correct 5-bits in error and can detect 6-bits in error. By using multiple-bit EDC in the controller for main memory, it is no longer necessary that all DRAM devices be ostensibly "perfect." A certain density of non-functional memory cells can be tolerated, yet the memory system will still return perfect data. The added cost of multiple-bit EDC, including the added cost of extra storage for the check bits and the EDC circuit itself, is more than compensated by reduced cost of the DRAMs. In a addition the computer system includes a solid-state disk type memory for a computer system is able to make use of DRAM memory devices having a relatively high level of bad cells (hard faults). An EDC circuit is employed to perform a Reed-Solomon code type of error detection and correction. A primary feature is the recognition that it is no longer necessary that all DRAM devices be ostensibly "perfect." A certain density of non-functional memory cells can be tolerated, yet the memory system will still return perfect data. The added cost of multiple-bit EDC, including the added cost of extra storage for the check bits and the EDC circuit itself, is more than compensated by reduced cost of the DRAMs. A preferred data formatter circuit to convert between symbol and word data is also described.
摘要:
Methods of forming soft connective tissue compositions such as skin equivalents, compositions made by the methods and their uses. In particular, a method of forming a connective tissue equivalent, comprising the steps of: (i) incubating collagen-producing cells in or on a support matrix; (ii) inducing and/or enhancing collagen production by the collagen-producing cells to form a collagenous construct and degradation and replacement of the support matrix; (iii) freeze-drying the construct; and (iv) re-populating the freeze-dried construct with collagen-producing cells and/or epithelial cells and/or endothelial cells and/or mesenchymal cells, thereby forming a connective tissue equivalent, wherein: (a) the collagen-producing cells are substantially fibroblasts; for example human neonatal dermal fibroblasts; (b) the support matrix is a provisional support matrix in which the support matrix is a fibrin matrix, for example formed by thrombin-mediated polymerisation of fibrinogen; and (c) as a result of the collagen production by the collagen-producing cells the provisional fibrin support matrix is digested by the cells and is replaced by collagen, thereby essentially replacing the provisional fibrin matrix with a collagen matrix synthesised in situ by the cells.
摘要:
An air-bearing center-guiding apparatus 10 and a method are disclosed for supporting and laterally center-guiding thin flexible webs of paper or plastic under 15 mils in thickness. The apparatus comprises a web support and guide member 22 having an inner surface and an outer web-facing surface. Parallel rows of elongated spaced-apart guide apertures 34 extend longitudinally along edge regions of the web. Each guide aperture 34 is formed from a cylindrical opening in the web support and guide member 22 and extends substantially perpendicular to the web. Within each aperture a flat-sided dowel 60 is mounted to define a flow passage shaped in cross-section like a segment of a circle 62. Each circular-segment guide aperture 34 has a straight side 54 and a curved side 52 for directing a jet of air against the web edge 56. A plurality of the circular-segment guide apertures 34 develop a guiding force for holding lateral movement of the web to plus or minus 0.001 inch (0.0254 mm). A row of web-support apertures 32, separate from the guide apertures 34, is provided between the rows of guide apertures 34 to form an air bearing for supporting the web.
摘要:
An air-bearing center-guiding apparatus is disclosed for supporting and laterally center-guiding thin, flexible webs of paper or plastic under 15 mils in thickness. The apparatus comprises a web support and guide member 10 having an inner surface 58 and an outer web-facing surface 60. The web support and guide member 10 comprises a base member 14 for supporting an inner ring 22, an end cap 38, and a center ring 28 interposed therebetween. Parallel, circumferentially extending rows of circumferentially elongated and spaced-apart guide apertures 62 are provided in the web support and guide member 10 along edge regions of the web. The guide apertures 62 are formed between end surfaces 46 of the center ring 28 and interengaging end surfaces of the inner ring 22 and end cap rings 38. Each guide aperture 62 extends substantially perpendicular to the surface of the web and defines in cross-section an opening having a straight side and a curved side for directing jets of air against the web edges for developing a guiding force for holding lateral movement of the web to plus or minus 0.001 inch (0.0254 mm). A row of support apertures 56, separate from the guide apertures 62, is provided in the center ring 28 between the rows of guide apertures 62 to form an air-bearing for the web.
摘要:
An air treating gel comprises an aqueous medium, at least one volatile air treating component and a gelling agent, characterized in that the gelling agent consists of the reaction product of a water soluble cellulose derivative and a metal salt.The invention also covers an apparatus for continuously producing the above air treating gel comprising a pair of containers holding the aqueous solution of said cellulose derivative and the slurry of said metal salt and said volatile air treating component respectively, mixing means connected to the containers for mixing and reacting the aqueous solution and slurry to form the gel, and transfer means for continuously transferring the aqueous solution and slurry in predetermined volume proportion from the containers to the mixing means.
摘要:
The present invention relates to compositions and methods for tissue regeneration, particularly for treating skin lesions such as wounds. In one aspect, the invention provides wound healing composition characterized by the higher expression levels of phenotypic marker genes such as apolipoprotein D, matrix metalloprotease (2), collagen 3a1 and smooth muscle actin than the housekeeping gene ribosomal protein L32. The compositions and methods of the invention are useful especially for assisting the process of wound healing, particularly chronic open lesions that are slow to heal or resistant to healing.
摘要:
Methods of forming soft connective tissue compositions such as skin equivalents, compositions made by the methods and their uses. In particular, a method of forming a connective tissue equivalent, comprising the steps of: (i) incubating collagen-producing cells in or on a support matrix; (ii) inducing and/or enhancing collagen production by the collagen-producing cells to form a collagenous construct and degradation and replacement of the support matrix; (iii) freeze-drying the construct; and (iv) re-populating the freeze-dried construct with collagen-producing cells and/or epithelial cells and/or endothelial cells and/or mesenchymal cells, thereby forming a connective tissue equivalent, wherein: (a) the collagen-producing cells are substantially fibroblasts; for example human neonatal dermal fibroblasts; (b) the support matrix is a provisional support matrix in which the support matrix is a fibrin matrix, for example formed by thrombin-mediated polymerisation of fibrinogen; and (c) as a result of the collagen production by the collagen-producing cells the provisional fibrin support matrix is digested by the cells and is replaced by collagen, thereby essentially replacing the provisional fibrin matrix with a collagen matrix synthesised in situ by the cells.
摘要:
The present invention relates to compositions and methods for tissue regeneration, particularly for treating skin lesions such as wounds. In one aspect, the invention provides a wound healing composition comprising living cells such as fibroblasts within a support matrix such as fibrin, in which the cells have a wound healing phenotype, and in which the composition is single layered and has been incubated for up to about 8 days to allow development of the wound healing phenotype. The compositions and methods of the invention are useful especially for assisting the process of wound healing, particularly chronic open lesions that are slow to heal or resistant to healing.