Frantzen Krarup (drakestart2)
Infants tend to forget experiences much more rapidly than older individuals, a phenomenon referred to as infantile amnesia. This robust, cross-species phenomenon is commonly used to examine memory development. However, in this set of experiments, we examined the novel hypothesis that the expression of infantile amnesia is related to resilience/vulnerability. We conditioned infant rats to associate a white noise with shock. Animals were tested for memory of the association ~1 week later. We found that infants that expressed better memory of the aversive association emitted more vocalizations (indicative of higher levels of distress) when separated from their mother earlier in infancy (Experiment 1). Better expression of memory in infancy also predicted higher levels of conditioned fear (Experiment 2) and anxiety-like behavior (in a light-dark box; Experiment 3) in adulthood. Furthermore, probiotic-treatment administered early in development reduced anxiety-like behavior in animals that exhibited good expression of memory for an aversive association learnt in infancy (Experiment 4). However, the same treatment was ineffective if administered in adulthood. Taken together, these results suggest that individual differences in infants' memory for an aversive association predict anxiety-like behavior throughout development, and that early administration of probiotics can reduce anxiety-like behavior in "at-risk" animals.Symmetric echo-planar spectroscopic imaging (EPSI) supports higher spectral bandwidth and improves signal-to-noise efficiency compared to flyback EPSI with the same readout bandwidth, but suffers from artifacts that are associated with non-uniform temporal sampling in k-t space. Our goal is to eliminate these artifacts and enhance observation of hyperpolarized [1-13C] pyruvate and its metabolites using symmetric EPSI. We used symmetric EPSI to efficiently acquire radially encoded spectroscopic imaging projections with a spectral under-sampling scheme that was optimized for HP pyruvate and its metabolites. A simple approach called selective correction of off-resonance effects (SCORE) was developed and applied to eliminate spectral artifacts. Y-27632 datasheet Simulations were used to assess the relative SNR performance of this technique, and a phantom study was carried out at 3 T to evaluate this method and compare it with alternative strategies. SCORE correction eliminated spectral artifacts due to chemical shift and non-uniform sampling in time. It is also compatible with established methods to eliminate artifacts caused by eddy currents. SCORE corrected symmetric EPSI supported maximal EPSI spectral bandwidth and improved SNR efficiency. Symmetric EPSI with SCORE correction offers a straightforward, efficient, and effective framework for assessment of hyperpolarized [1-13C] pyruvate and its metabolites.Resin-based composite has overtaken dental amalgam as the most popular material for the repair of lost or damaged tooth structure. In spite of the popularity, the average composite lifetime is about half that of amalgam restorations. The leading cause of composite-restoration failure is decay at the margin where the adhesive is applied. The adhesive is intended to seal the composite/tooth interface, but the adhesive seal to dentin is fragile and readily degraded by acids, enzymes and other oral fluids. The inherent weakness of this material system is attributable to several factors including the lack of antimicrobial properties, remineralization capabilities and durable mechanical performance - elements that are central to the integrity of the adhesive/dentin (a/d) interfacial seal. Our approach to this problem offers a transition from a hybrid to a biohybrid structure. Discrete peptides are tethered to polymers to provide multi-bio-functional adhesive formulations that simultaneously achieve antimicrobial and remineralization properties. The bio-additive materials design combines several functional properties wit