Search results for " Plastic"
showing 10 items of 3463 documents
Synthesis and Characterization of Base Labile Poly(N-isopropylacrylamide) Networks Utilizing a Reactive Cross-Linker
2008
Topologically Controlled Interpolyelectrolyte Complexes
2008
The complexation of a cylindrical polyelectrolyte−brush−surfactant complex (PMMPSS−C12) and an oppositely, highly charged cylindrical polyelectrolyte−brush (PMMPEI−PEO) in dimethylformamide (DMF) l...
A Combined DPE/Epoxide Termination Strategy for Hydroxyl End-Functional Poly(2-vinylpyridine) and Amphiphilic AB2-Miktoarm Stars
2011
Reconstruction of full thickness scalp defects after tumour excision in elderly patients: our experience with Integra dermal regeneration template.
2010
Summary Background Scalp reconstruction after wide tumor excision is particularly challenging. Free tissue transfers, local flaps, or skin grafts can be used but present some disadvantages especially with old patients with local advanced cancers, systemic diseases and in patients with a prior history of recurring scalp skin cancers in which the risk of burying a recurring tumor with a flap is likely. The Authors expose their early experience with Integra ® dermal regeneration template for scalp reconstruction after scalp tumor excision. Methods Eight patients with primary or secondary scalp tumor underwent a first surgical procedure under local anaesthesia for tumor removal and Integra ® po…
Thermodynamics-based gradient plasticity theories with an application to interface models
2008
AbstractIn the framework of small deformations, the so-called residual-based gradient plasticity theory is reconsidered and improved. Using the notion of moving geometrically necessary dislocations (GNDs), suitable micromechanics interpretations are heuristically given for the higher order boundary conditions and the long distance particle interactions. Also, a comparison is made between this theory and the analogous virtual work principle (VWP)-based one, whereby their respective conceptual and methodological features are pointed out. The conditions under which the two theories lead to a same constitutive model are investigated, showing that, correspondingly, a certain indeterminacy exhibi…
Apparent interfacial shear strength of short-flax-fiber/starch acetate composites
2016
Abstract The paper deals with an indirect industry-friendly method for identification of the interfacial shear strength (IFSS) in a fully bio-based composite. The IFSS of flax fiber/starch acetate is evaluated by a modified Bowyer and Bader method based on an analysis of the stress–strain curve of a short-fiber-reinforced composite in tension. A shear lag model is developed for the tensile stress–strain response of short-fiber-reinforced composites allowing for an elastic-perfectly plastic stress transfer. Composites with different fiber volume fractions and a variable content of plasticizer have been analyzed. The apparent IFSS of flax/starch acetate is within the range of 5.5–20.5 MPa, de…
Early Social Isolation Stress and Perinatal NMDA Receptor Antagonist Treatment Induce Changes in the Structure and Neurochemistry of Inhibitory Neuro…
2017
AbstractThe exposure to aversive experiences during early life influences brain development and leads to altered behavior. Moreover, the combination of these experiences with subtle alterations in neurodevelopment may contribute to the emergence of psychiatric disorders, such as schizophrenia. Recent hypotheses suggest that imbalances between excitatory and inhibitory (E/I) neurotransmission, especially in the prefrontal cortex and the amygdala, may underlie their etiopathology. In order to understand better the neurobiological bases of these alterations, we studied the impact of altered neurodevelopment and chronic early-life stress on these two brain regions. Transgenic mice displaying fl…
Lack of APP and APLP2 in GABAergic Forebrain Neurons Impairs Synaptic Plasticity and Cognition.
2020
AbstractAmyloid-β precursor protein (APP) is central to the pathogenesis of Alzheimer’s disease, yet its physiological functions remain incompletely understood. Previous studies had indicated important synaptic functions of APP and the closely related homologue APLP2 in excitatory forebrain neurons for spine density, synaptic plasticity, and behavior. Here, we show that APP is also widely expressed in several interneuron subtypes, both in hippocampus and cortex. To address the functional role of APP in inhibitory neurons, we generated mice with a conditional APP/APLP2 double knockout (cDKO) in GABAergic forebrain neurons using DlxCre mice. These DlxCre cDKO mice exhibit cognitive deficits i…
PSA-NCAM is expressed in immature, but not recently generated, neurons in the adult cat cerebral cortex layer II
2011
Neuronal production persists during adulthood in the dentate gyrus and the olfactory bulb, where substantial numbers of immature neurons can be found. These cells can also be found in the paleocortex layer II of adult rodents, but in this case most of them have been generated during embryogenesis. Recent reports have described the presence of similar cells, with a wider distribution, in the cerebral cortex of adult cats and primates and have suggested that they may develop into interneurons. The objective of this study is to verify this hypothesis and to explore the origin of these immature neurons in adult cats. We have analyzed their distribution using immunohistochemical analysis of the …
Intracellular Na+ concentration influences short-term plasticity of glutamate transporter-mediated currents in neocortical astrocytes.
2012
Fast synaptic transmission requires a rapid clearance of the released neurotransmitter from the extracellular space. Glial glutamate transporters (excitatory amino acid transporters, EAATs) strongly contribute to glutamate removal. In this work, we investigated the paired-pulse plasticity of synaptically activated, glutamate transporter-mediated currents (STCs) in cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and GABAB receptor antagonists. In experiments with low [Na+]i (5 mM) intrapipette solution, STCs elicited by paired-pulse stimulation demonstrated paired-pulse facilitation (…