24 research outputs found
Terrestrial laser scanning as a key element in the integrated monitoring of tidal influences on a twin-tube concrete tunnel
In 2012, for the first time in Belgium, integrated monitoring was carried out to assess the deformations of a twin-tube tunnel below the River Scheldt in Antwerp under the influence of estuarine tides. Levelling measurements during a tide cycle showed a variation in the height of levelling bolts of up to 10mm between low and high tide. Simultaneous strain-gauge measurements also showed a significant difference in strains. A deformation of the tunnel section during each twice-daily tide cycle, resulting in an eccentric egg or pumpkin shape, could hold large risks for the strength and durability of the tunnel structure. However, laser scanning results showed that there were no significant deformations of the tunnel's shape during the tide cycle. The laser scanning measurements resulted in a more thorough view of the deformation pattern which was much needed and improved the long-term risk assessment of the tunnel
Characterization of brain neurotensin receptors using a new tool : levocabastine
Levocabastine, a non-peptide antihistamine compound, inhibits, with high affinity and selectivity, neurotensin binding to the low affinity neurotensin sites (NTL-sites) in rat, mouse and hamster brain but not in various other mammalian species including man. The use of levocabastine enable to study separately the binding of radiolabelled neurotensin to the high affinity neurotensin binding sites (NTH-sites) and to the NTL-sites. NTH-sites are densely present in the substantia nigra, ventral tegmental area, cingulated cortex, entorhinal cortex, olfactory bulb, rhinal sulcus, superior colliculis and ventral dentate gyrus. They display the properties of a neurotransmitter receptor binding site and should be considered as the physiologically relevant neurotensin receptor. NTH-sites are situated on dopaminergic nerve ending both in the nigrostriatal and mesolimbic pathways. NTH- and NTL-sites are not high and low affinity states of a same receptor, since both neurotensin binding sites show different subcellular distribution patterns after isopycnic centrifugation in sucrose density gradients. Although they show strict stereospecific properties, NTL-sites have, as yet, no defined functional role and are likely to be considered as chemical recognition sites for neurotensin and for levocabastine. NTL-sites are homogeneously present in the various brain areas of the rat brain. They are distinct entities and have no relationship with the histamine-H1 receptors. NTL-sites are suggested to be localized on glial cells. During the ontogenic development, NTJ-sites peak in most brain areas between the 5th and the 10th day of postnatal life. They are then predominant in the cortical areas, but subsequently dramatically regress in many brain areas. In the substantia nigra NTH-sites peak at 15 days and slightly decrease in adulthood. NTL-sited start to appear only from the 15th day of life. Evidence is given herewith that only the NTH-sites can be involved with the regulation of the dopamine release in the rat brain. This knowledge is of essential importance for the development of neurotensin antagonists with potential therapeutic potency is psychiatry, which should therefore be compounds directed exclusively towards the high affinity neurotensin binding sitesThèse de doctorat en sciences biomédicales -- UCL, 198