Time analysis of alveolar ridge preservation using a combination of mineralized boneâ plug and denseâ polytetrafluoroethylene membrane: A histomorphometric study

BackgroundThe objective of this study was to histologically evaluate and compare vital bone formation, residual graft particles, and fraction of connective tissue (CT)/other tissues between three different time points at 2â month intervals after alveolar ridge preservation with a cancellous allograft and denseâ polytetrafluoroethylene (dâ PTFE) membrane.MethodsRidge preservation with a cancellous allograft and dâ PTFE membrane was performed at 49 extraction sockets (one per patient). Volunteers were assigned to implant placement at three different time points of 2, 4, and 6 months, at which time core biopsies were obtained. Histomorphometric analysis was performed to determine the percentages of vital bone, residual graft particles, and connective tissue/other nonâ bone components, and subjected to statistical analyses.ResultsThere was a statistically significant difference in the amount of vital bone at every time point from 28.31% to 40.87% to 64.11% (at 2â , 4â , and 6â month groups, respectively) (P < 0.05). The percentage of residual graft particles ranged from 44.57% to 36.16% to 14.86%, showing statistical significance from 4 to 6 months (21.29%, P < 0.001), and 2 to 6 months (29.71%, P < 0.001), while there were no significant differences for the amount of CT/other tissue among the different time points.ConclusionsThis study provided the first histologic comparison of alveolar ridge preservation using a cancellous allograft and dâ PTFE membrane at three different time points. Extraction sockets that healed for 6 months produced the highest amount of vital bone in combination with the least percentage of residual graft particles, while similar results were observed for the fraction of CT/other tissues between the three time points.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154387/1/jper10405.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154387/2/jper10405_am.pd

Rare appearance of Candida tropicalis infection of the brain: Multiple micro-abscesses combined with diffuse hemorrhages

AbstractWe report a case of cerebral Candida tropicalis infection in a middle-aged patient who suffered from multiple cerebral micro-abscesses associated with diffuse hemorrhage due to perforation of esophagus. MRI revealed multiple irregular, nodular, ring-like enhancing lesions with restricted diffusion and multiple micro-hemorrhages as well as some leptomeningeal enhancements. Blood, sputum and urine cultures showed Candida tropicalis. The lesions were resolved after the patient was given early and effective treatment of anti-fungal medicine. The imaging findings provided limited differential diagnosis, leading to early diagnosis and treatment for this patient

Theoretical study of small signal modulation behavior of Fabry-Perot Germanium-on-Silicon lasers

This work investigated the small signal performance of Fabry-Perot Ge-on-Si lasers by modeling and simulations. The 3dB bandwidth dependence on the structure parameters such as poly-Si cladding thickness, Ge cavity width and thickness, and minority carrier lifetime were studied. A 3dB bandwidth of 33.94 GHz at a biasing current of 270.5 mA is predicted after Ge laser structure optimization with a defect limited carrier lifetime of 1 ns