The encoding of word forms into memory may be challenging for college students with developmental language impairment

Purpose: To describe the word-learning problems characteristic of developmental language impairment (LI).

Method: College students with LI (n?=?39) or normal language development (ND, n?=?40) attempted to learn novel word forms. Training for half of the words was meaning-focused; training for the other half was form-focused. Form recognition and stem completion tasks administered immediately after training tapped encoding of the lexical configuration and a repetition of the stem completion task one week later tapped consolidation. A visual world paradigm tapped lexical engagement.

Result: At the immediate post-test, the LI group was poorer at recognition and completion of word forms than their ND peers, suggesting a deficit in encoding the lexical configuration. However, the gap between the LI and ND groups in stem completion did not grow over the week, suggesting intact consolidation. Form-focused training yielded better performance than meaning-focused training at immediate- and one week tests. For both groups, newly trained words slowed the recognition of familiar English words, revealing lexical engagement.

Conclusion: The encoding of word-form configurations is challenging for some, but not all, college students with LI. Training that encourages a focus on the form may be a useful part of vocabulary intervention for those affected.     

[18F]Fluoride labelling of macromolecules in aqueous conditions: silicon and boroaryl‐based [18F]fluorine acceptors, [18F]FDG conjugation and Al18F chelation

[¹⁸F]Fluorination is usually carried out by nucleophilic substitution reactions entailing the use of stringent conditions. A number of novel techniques including silicon and boron‐based fluoride acceptor molecules, [¹⁸F]fluoro‐2‐deoxy‐ d ‐glucose and chelation of the Al¹⁸F complex have been employed recently to achieve [¹⁸F]radiolabelling of macromolecules. These approaches are reviewed herein. Copyright © 2012 John Wiley & Sons, Ltd.     

Screw retained vs. cement retained implant‐supported fixed dental prosthesis

A fixed dental prosthesis can be secured to an endosseous implant via cementation (using a provisional or definitive cement) on an implant abutment that is screw retained to the implant or directly in the implant via screw retention. The clinical decision as to which retention system best suits the individual patient depends on several factors. The aim of this review is to present a detailed overview of the factors potentially influencing whether to choose screw retention or cement retention. These factors include the individual indication, advantages and disadvantages of the different retention mechanisms, the retention provided, retrievability, provisionalization, esthetics and clinical performance, including failures and complications. The results of recently published systematic reviews on this topic are discussed and an overview is provided. A decision tree is presented to facilitate the clinical selection of the retention type. This overview concludes that the choice of retention type (screw retained or cement retained) might not influence the overall survival of the implant‐supported fixed dental prosthesis, but may be responsible for the development of certain complications. The decision may depend on technical feasibility and on weighing the pros and cons.