(C) 2010 American Institute of Physics. [doi:10.1063/1.3463405]“
Standardized experimental investigations determining the critical-size JQ-EZ-05 inhibitor defect (CSD) in the mandible of miniature pigs are still lacking. The aim of the present study was to obtain information about the new bone formation in created defects of varying sizes.
Study design. Marginal resection of the alveolar crest of the lower jaw was performed in 3 female miniature pigs. The animals used in the study were 3 years of age and weighed similar to 55 kg. For histologic evaluation the dental implants were harvested with the surrounding bone tissue 10 weeks after implant placement. For this, bone segments including the implants were removed from each side of the mandible. The sizes of the resected LY2157299 bone blocks varied, showing the following volumes: 10.1 cm(3), 4.2 cm(3), and 1.9 cm(3). Periosteal coverage of the defects was performed. Computerized tomography (CT) of the skull of the miniature
pig was performed immediately after the surgical procedure as well as 6 weeks later using a 64-channel mult-slice scanner.
Results. The CT showed that 6 weeks after obtaining the biopsies, the filling of the defects with new bone varied. The percentage of newly formed bone in relation to the size of the original defect was 57.4% for the small- and 87.2% for the middle-sized defect. The large-sized defect showed 75.5% newly formed bone compared with baseline.
Conclusion. Considering the amount of new bone formation found within this study, it is questionable if the critical defect size of 5 cm(3) stated in the literature is valid. Further research concerning the mandibular model in minipigs is required and more refinement needed to
assure selleck kinase inhibitor a standardized CSD, allowing qualitative and quantitative evaluation of bone grafts and bone graft substitutes. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:699-706)”
“We study the dependence of the hole barrier height at the metal/alpha-Ge2Sb2Te5 interface as a function of nitrogen doping in Ge2Sb2Te5 as well as the vacuum work function of the metal. Materials parameters such as the band gap, dielectric constant, and electron affinity values of these nitrogen-doped films were also determined. All Ge2Sb2Te5 films studied in this work are amorphous. Following further physical analysis, the effective work functions of metals on nitrogen-doped Ge2Sb2Te5 films were obtained and found to differ from that of their values in vacuum. This led to the extraction of the slope parameter S, and charge neutrality level Phi(CNL), which characterizes Ge2Sb2Te5.