METHODS: Five silicon-injected fixed cadaver heads were dissected. The arch of C1 and dens were preserved and reconstructed using odontoid screws and miniplates.
Once the feasibility of the technique was established, we biomechanically tested 6 cadaveric occiput-C2 specimens in 3 phases: (1) intact/normal range of motion (ROM), (2) after transection of dens and C1 arch, and (3) with odontoidoplasty using odontoid screws and C1 arch reconstruction.
RESULTS: After odontoidectomy and arch removal, angular ROM increased significantly in all directions of loading. Resection increased flexion-extension at the occiput-C1 and at C1-C2 by 21% and 129%, respectively. Reconstruction https://www.selleckchem.com/products/as1842856.html slightly increased flexion-extension stability (16% and 107%, respectively) relative to normal. With 70 N applied compression, the C1 ring separation was 1145% greater than normal. After reconstruction, GW3965 the separation was only 89% greater than normal (statistically significant, P = .002).
CONCLUSION: C1 arch reconstruction with or without
odontoidoplasty restores only partial angular stability of the atlantoaxial joint but provides restoration of the ability of the C1 lateral masses to resist splaying, often observed as postodontoidectomy cranial settling.”
“Aims:
When subjected to dynamic temperatures surpassing the expected maximum growth temperature, Escherichia coli K12 MG1655 shows disturbed growth curves. These irregular population dynamics were explained by considering two subpopulations, i.e. a thermoresistant and a thermosensitive one (Van Derlinden et al. 2010a). In this paper, the influence of the initial cell concentration on the subpopulations’ dynamics is evaluated.
Methods and Results:
Experiments
were performed in a bioreactor with the temperature increasing from 42 to 65 center dot 2 degrees C (1 and 4 degrees C h-1) with varying initial cell concentrations [6, 12 and 18 ln(CFU ml-1)]. When started from the highest cell concentration, the population was characterized by a higher overall maximum growth temperature and a higher inactivation temperature. For all experimental set-ups, resistant cells were still growing at the final temperature of 65 center dot 2 degrees during C.
Conclusions:
The initial cell concentration had no effect on temperature resistance. The increase in temperature resistance of the sensitive subpopulation was because of the change of the physiological state to the stationary phase.
Significance and Impact of the Study:
A higher initial cell concentration leads to higher heat stress adaptation when cultures reach a maximum cell concentration. The observed growth at a temperature of 65 center dot 2 degrees C is very important for food safety and the temperature treatment of micro-organisms.”
“BACKGROUND: The efficacy of deep brain stimulation (DBS) is highly dependent on the accuracy of lead placement.