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- Badylak, S, et al.
(författare)
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Resorbable Bioscaffold for Esophageal Repair in a Dog Model
- 2000
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Ingår i: Journal of Pediatric Surgery. - : Elsevier BV. - 0022-3468 .- 1531-5037. ; 35:7, s. 1097-1103
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Porcine-derived, xenogeneic extracellular matrix (ECM) derived from either the small intestinal submucosa (SIS) or urinary bladder submucosa (UBS) was used as a tissue scaffold for esophageal repair in a dog model. Methods: Patch defects measuring approximately 5 cm in length and encompassing 40% to 50% of the circumference of the esophagus or complete circumferential segmental defects measuring 5 cm in length were created by surgical resection in healthy adult female dogs. The defects were repaired with ECM scaffolds derived from either SIS or UBS. The animals were kept alive for periods ranging from 4 days to 15 months. Results: The xenogeneic scaffolds used for repair of the patch defects were resorbed completely within 30 to 60 days and showed replacement by skeletal muscle, which was oriented appropriately and contiguous with adjacent normal esophageal skeletal muscle, organized collagenous connective tissue, and a complete and intact squamous epithelium. No signs of clinical esophageal dysfunction were seen in any of the animals with the patch defect repair. The xenogeneic scaffolds configured into tubes for repair of the segmental defects all showed stricture within 45 days of surgery. Conclusion: These ECMs show promise as a treatment option for esophageal repair, but stricture remains problematic for complete tube grafts.
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| 2. |
- Graham, A.C., et al.
(författare)
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0.7 Analogue structures and exchange interactions in quantum wires
- 2004
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Ingår i: Solid State Communications. - : Elsevier BV. - 0038-1098 .- 1879-2766. ; 131:9-10 SPEC. ISS., s. 591-597
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Tidskriftsartikel (refereegranskat)abstract
- We present experimental studies of crossings of spin-split one-dimensional subbands in ballistic quantum wires in an in-plane magnetic field B ?. At low electron densities, a spontaneous spin-splitting occurs as subbands cross, which gives rise to additional non-quantised conductance structures called 0.7 analogues. We analyse the data within a spin-density-functional model, which includes exchange interactions in a magnetic field. Focussing on the region of the crossings of spin-split subbands, it is found that the energy levels rearrange as they cross due to exchange interactions. © 2004 Elsevier Ltd. All rights reserved.
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| 3. |
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| 4. |
- Starikov, Anton, et al.
(författare)
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Effects of accidental microconstriction on the quantized conductance in long wires
- 2003
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Ingår i: Proceedings of SPIE, the International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5023, s. 267-270
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We have investigated the conductance of long quantum wires formed in GaAs/ AlxGa1-x As heterostructures. Using realistic fluctuation potentials from donor layers we have simulated numerically the conductance of four different kinds of wires. While ideal wires show perfect quantization, potential fluctuations from random donors may give rise to strong conductance oscillations and degradation of the quantization plateaux. Statistically there is always the possibility of having large fluctuations in a sample that may effectively act as a microconstriction. We therefore introduce microconstrictions in the wires by occasional clustering of donors. These microconstrictions are found to restore the quantized plateaux. A similar effect is found for accidental lithographic inaccuracies.
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