Search results for "plastic"
showing 10 items of 7296 documents
Divu diazepāma devu ietekme uz Alcheimera slimības modeļa dzīvnieku sinaptisko plasticitāti un acetilholīna šķelšanu
2018
Šī darba mērķis bija noteikt gamma-aminosviestskābes (GABA) receptora benzodiazepīna saita agonista diazepāma (DZP) ļoti zemas (0,05 mg/kg) un vidējās (1 mg/kg) devas efektus uz Alcheimera slimības (AD) modeļa žurku sinaptisko plasticitāti un acetilholīna šķelšanu. Rezultāti rāda, ka AD modeļa žurku smadzenēs tika būtiski samazināta sinaptofizīna-1 (SYP) ekspresija un būtiski pieauga acetilholīna šķelšanās. Ļoti zema (0,05 mg/kg) diazepāma deva spēja uzlabot sinaptisko plasticitāti, savukārt abas (0,05 mg/kg un 1 mg/kg) diazepāma devas būtiski normalizēja acetilholīna šķelšanos AD modeļa žurku garozā un hipokampā. Iegūtie dati norāda uz ļoti zemas un vidējas devas diazepāma neiroprotektīvo …
Design, synthesis and structure-activity relationship of 2-(3',4',5'-trimethoxybenzoyl)-benzo[b]furan derivatives as a novel class of inhibitors of t…
2009
The biological importance of microtubules in mitosis and cell division makes them an interesting target for the development of anticancer agents. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. Thus, a new class of inhibitors of tubulin polymerization based on the 2-(3′,4′,5′-trimethoxybenzoyl)-benzo[b]furan molecular skeleton, with electron-donating (Me, OMe or OH) or electron-withdrawing (F, Cl and Br) substituents on the benzene ring, was synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization and cell cycle effects. Adding a methyl group at the C-3 position resulted in increased activity. The most prom…
Improved camouflage through ontogenetic colour change confers reduced detection risk in shore crabs
2019
Abstract Animals from many taxa, from snakes and crabs to caterpillars and lobsters, change appearance with age, but the reasons why this occurs are rarely tested.We show the importance that ontogenetic changes in coloration have on the camouflage of the green shore crabs (Carcinus maenas), known for their remarkable phenotypic variation and plasticity in colour and pattern.In controlled conditions, we reared juvenile crabs of two shades, pale or dark, on two background types simulating different habitats for 10 weeks.In contrast to expectations for reversible colour change, crabs did not tune their background match to specific microhabitats, but instead, and regardless of treatment, all de…
ANAPLASTIC THYROID CANCER: A CASE SERIES WITH A WIDE SPECTRUM OF TREATMENT IN EMERGENCY
2019
Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies of the neck, and for the majority of these patients the cause of death is a compromised airway, metastatic disease, superior vena cava syndrome, asphyxiation, or exsanguination. In case of the airway being compromised, emergency treatment is mandatory but not well defined. We report 4 different kinds of acute presentation of complications. Anaplastic thyroid cancer; diagnostic, clinical and prognostic indication, evaluation of choice of treatment are discussed. The spectrum of treatment varies from observation and preservation of the airway from a tracheostomy to extensive surgery. When a potentially curative rese…
A Green Approach for Recycling Compact Discs
2023
Compact discs (CDs) and digital versatile discs (DVDs) are mainly made by polycarbonate disc, a thin layer of aluminum or silver, a thin layer of a coating and a thin layer of a label of paper or PET. The recycling of these discs is difficult due to the removal of these non-polymeric layers and to our best knowledge, no industrial plants have been resent for their recycling. In this work, we propose a facile way to remove the non-polymeric layers and investigate the effect of the repetitive extrusion process on the processability and on the mechanical properties of the recycled polycarbonate. A few works have been published dealing with both the removal of the non-polymeric layers and the m…
Preliminary Evaluation of Plasmix Compound from Plastics Packaging Waste for Reuse in Bituminous Pavements
2021
Finding an appropriate technical solution for reusing waste plastics is crucial for creating a circular plastic economy. Although mechanical recycling is the best option for recycling post-consumer plastics, some heterogeneous mixed plastics cannot be recycled to produce secondary material due to their very low properties. In this case, alternative routes should be considered in order to limit their disposal as much as possible. Therefore, in order to solve the environmental problems in the landfills of plastic waste recycling, and to improve the mechanical performance of bitumen for road pavement, the reuse of these post-consumer plastic wastes are preliminarily evaluated for the modificat…
CA3–CA1 long‐term potentiation occurs regardless of respiration and cardiac cycle phases in urethane‐anesthetized rats
2023
Breathing and heartbeat synchronize to each other and to brain function and affect cognition in humans. However, it is not clear how cardiorespiratory rhythms modulate such basic processes as synaptic plasticity thought to underlie learning. Thus, we studied if respiration and cardiac cycle phases at burst stimulation onset affect hippocampal long-term potentiation (LTP) in the CA3–CA1 synapse in urethane-anesthetized adult male Sprague–Dawley rats. In a between-subjects design, we timed burst stimulation of the ventral hippocampal commissure (vHC) to systole or diastole either during expiration or inspiration and recorded responses throughout the hippocampus with a linear probe. As classic…
Multidomain SBEM analysis for two dimensionalelastoplastic-contact problems
2012
The Symmetric Boundary Element Method based on the Galerkin hypotheses has found application in the nonlinear analysis of plasticity and contact-detachment problems, but dealt with separately. In this paper we wants to treat these complex phenomena together. This method works in structures by introducing a subdivision into sub-structures, distinguished into macroelements, where elastic behaviour is assumed, and bem-elements, where it is possible for plastic strains to occur. In all the sub-structures, elasticity equations are written and regularity conditions in weighted (weak) form and/or in nodal (strong) form between boundaries have to be introduced, to attain the solving equation system.
Protein levels of brain-derived neurotrophic factor in the hippocampus of low/high aerobic capacity rats
2010
Hippocrates and Plato have first documented the connection between a healthy mind and body, during a period which launched analytical thinking and philosophy in Ancient Greece. Modern research has also indicated the contribution of an active lifestyle to enhanced brain performance and decreased incidence of neurodegenerative diseases and mood disorders such as Alzheimer’s disease and depression respectively. This has been hypothesized to emerge through mechanisms which are enhanced by exercise and contribute on brain plas-ticity and health. The Neurotrophins hypothesis implicates several molecules in brain plasticity and healthy aging. Among them, Brain-derived Neurotrophic Factor (BDNF) ha…
Effect of oil lamination between plasticized starch layers on film properties
2016
International audience; To reduce the hygroscopic character of biodegradable starch-based films, rapeseed oil was incorporated by lamination (starch-oil-starch 3-layers technique). The lipid lamination followed by starch solution casting step induced an emulsion type structure of dried films. Composite films are more opalescent and glossier than fatty free starch films. For all the films, structure is heterogeneous in the cross-section only. Adding fat induced a twice decrease of the tensile strength. Thermal gravimetry analysis did not show differences between films with and without oil. Lipid reduced the moisture absorption particularly at higher RH as well as the surface swelling index, …