Radiographic interpretation of experimentally produced bony lesions.
Abstract Simulated bone-destroying lesions were created at the apices of two molars and four premolars in a sectioned mandible. All radiographic variables other than bone loss were strictly controlled. Results indicated that in the premolar region it is possible to detect radiographic change without involvement of the junctional or cortical bone, at least to a greater degree than in the molar region.
Reliability of radiographical interpretations.
Seventy-nine dentists were asked to evaluate the radiographs of 10 endodontically treated teeth and to answer a questionnaire concerning the projected cases. A comparison of the answers revealed a great deal of disagreement among the observers. Of the dentists surveyed, 21.8% disagreed with themselves when shown the same case a second time. It was concluded that, although radiographs are indispensable to endodontic treatment and determination of success, the limitations of visual interpretation must always be considered.
Effect of Aeration and Agitation Regimes on Lipase Production by Newly Isolated Rhodotorula mucilaginosa–MTCC 8737 in Stirred Tank Reactor Using Molasses as Sole Production Medium
The influence of media and process parameters (aeration and agitation) on fermentation broth rheology and biomass formation has been studied in 1.5-l stirred tank reactor for lipase production using Rhodotorula mucilaginosa MTCC 8737. Molasses, as sole production medium, is used for lipase production by varying aeration (1, 2, and 3 vvm) and agitation speeds (100, 200, and 300 rpm). Maximum lipase activity of 72 U/ml was obtained during 96 h of fermentation at 2 vvm, 200 rpm, pH 7, and 25 ± 2°C temperature. Lipase production kinetics with respect to dry cell weight of biomass showed YP/S of 25.71 U/mg, specific product formation of 10.9 U/mg DC, and YX/S 2.35 mg/mg. Maximum lipase activity (MC 2) of 56 U/ml was observed at 1% molasses, and a further increase in the molasses concentration of (%) 1.5 and 2 inhibited the product formation of lipase with 15 and 8.5 U/ml, respectively. The production kinetics of molasses media showed YP/X was 14 U/mg DC, YP/S 16 U/mg, and YX/S 1.14 mg/mg during 96 h of bioreactor operation. The kLa values for all batches (MC 1–MC 4) at 96 h of fermentation were 32, 28, 21, and 19/h, and the |oxygen transfer rate were 54.4, 56, 35.7, and 17.29 mg/l h, respectively. Increase in molasses concentration resulted in decreased lipase activity by increase in viscosity of the fermentation broth.