Disposable plastic rodent feeders for use in an automated filling system.

Rodent feeder devices are often made of reusable, sanitizable materials such as glass and stainless steel. As part of an initiative at the authors' facility to automate the feeder filling process, disposable plastic feeding cups were proposed as a preferable alternative to standard feeders for use in a filling machine. The authors tested and validated designs for rodent meal-type feeder assemblies that incorporated plastic cups. Assemblies included stainless steel shields that prevented rats and mice from chewing on the plastic cups while allowing them full access to food. The use of disposable feeder cups that are filled and sealed automatically reduces labor associated with sanitation, enables staff to prepare feeders for several weeks in advance and limits personnel contact with feed that may contain harmful chemicals.

Dexmedetomidine infusion for sedation during fiberoptic intubation: a report of three cases.

We report three patients undergoing cervical spine surgery who required awake fiberoptic intubation, and in whom sedation was provided using a dexmedetomidine infusion. Dexmedetomidine was used to provide a moderate level of sedation without causing respiratory distress or hemodynamic instability during fiberoptic intubation. Conditions for intubation were acceptable in all three patients after co-administration of topical anesthesia. Dexmedetomidine may serve as a useful adjunct for this procedure. The anesthetic management and anesthetic implications of using dexmedetomidine infusions for awake fiberoptic intubation are discussed.

Ionic reaction of halogens with terminal alkenes: the effect of electron-withdrawing fluorine substituents on the bonding of halonium ions.

Ionic reactions of terminal alkenes with chlorine (Cl(2)), bromine (Br(2)), and iodine monochloride (ICl) are sensitive to the alkyl substituents, and the positions and number of vinyl fluorine atoms. These perturbations influence the symmetry of the halonium ion intermediates, which can be determined by the distribution of the Markovnikov to anti-Markovnikov products. A vinyl fluorine on the number-2 carbon favors an unsymmetrical intermediate with greater charge on the number-2 carbon unless the alkyl group is electron withdrawing. A vinyl fluorine on the terminal number-1 carbon favors positive charge development on that carbon unless a resonance stabilizing group is on the number-2 carbon. The symmetry of halonium ions with vinyl fluorines on both carbons-1 and -2 depends primarily on the characteristics of the alkyl substituent. Intermediates range from open-ions with the positive charge on carbon-2, to various bridged species, to open-ions on the terminal carbon.