Polymerization
reactions of N,N-dimethylacrylamide (DMA), N-isopropylacrylamide (NIPA), and acrylamide (AAm) in aqueous clay (Laponite) dispersions have been investigated by rheometry using oscillatory deformation tests. The gelation profile of AAm polymerization obeys typical gelation kinetics, while a reverse behavior was observed during the DMA or NIPA polymerizations. In the latter cases, after an abrupt increase in elastic and viscous moduli at the start of the reaction, they both decrease continuously during the Whole Worse of the gelation process. Creep-recovery tests performed on the final hydrogels indicate that the time-dependent C59 Wnt cost viscoelastic response of the gels derived from AAm is distinctly different from the other gels. The retardation time of AAm gel is about twice that of DMA or NIPA gels indicating higher mobility of
the crosslink zones in the former gel. As a consequence, a larger amount of energy is dissipated during the deformation of nanocomposite hydrogels based on AAm. Different extent of interactions between the clay particles and the monomers explains the results of observations. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 116: 2328-2335, 2010″
“Objective-To characterize injuries (on the basis of type and severity of injury and affected region of the body) among dogs participating in agility training and competition events and examine associations between injury characteristics and perceived causes of injury.
Design-Internet-based, A-1155463 research buy retrospective, cross-sectional survey.
Animals-3,801 this website privately owned dogs participating in agility training or trials.
Procedures-A retrospective electronic survey was developed to investigate demographic factors for dogs and handlers, frequency of participation in agility training and competition, and perceived causes and characteristics of injuries acquired by dogs during agility-related activities. Respondents were handlers recruited through member lists of large canine agility associations in Canada and the United Kingdom and through promotion on an agility blog site. Associations between cause and anatomic site or type of injury and between injury severity (mild
vs severe) and setting (competition vs practice) were investigated.
Results-Surveys were received from 1,669 handlers of 3,801 agility dogs internationally. Handler-reported data indicated 1,209 of 3,801 (32%) dogs had >= 1 injury; of 1,523 analyzed injuries, the shoulder (349 injuries), back (282), and neck (189) regions and phalanges (202) were predominantly affected. Soft tissue injuries leg, strain [muscle or tendon injury; 807], sprain [ligament injury; 312], and contusion [200]) were common. Injuries were most commonly incurred during interactions with bar jumps, A-frames, and dog walk obstacles (260, 235, and 177 of 1,602 injuries, respectively). Anatomic site and type of injury were significantly associated with perceived cause of injury.