We studied the topographical distribution of laser sensory thresholds on the human hairy skin, using a small laser beam for pinprick and a large beam for warmth sensations. The threshold for pinprick ...sensation correlated positively with the distance from the brain, suggesting that A delta nociceptors, the fibers which convey pinprick sensation, are more dense at proximal than at distal body sites. This finding adds information to skin biopsy studies of epidermal free nerve endings which showed a similar gradient, but could not differentiate small myelinated from unmyelinated fiber afferents. Possibly because of a diffuse low density of warmth receptors, laser warmth thresholds showed no trend.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We studied the topographical distribution of laser sensory thresholds on the human hairy skin, using a small laser beam for pinprick and a large beam for warmth sensations. The threshold for pinprick ...sensation correlated positively with the distance from the brain, suggesting that Aδ nociceptors, the fibers which convey pinprick sensation, are more dense at proximal than at distal body sites. This finding adds information to skin biopsy studies of epidermal free nerve endings which showed a similar gradient, but could not differentiate small myelinated from unmyelinated fiber afferents. Possibly because of a diffuse low density of warmth receptors, laser warmth thresholds showed no trend.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
R(+)-FIDA2, (R)-(+)-2,3-dimethoxy-5-iodo-N-(1-(4'-fluorobenzyl)-2-pyrrolid iny l)- methylbenzamide, is a new dopamine D2-like receptor imaging agent that can be labeled with either 123I or 18F for ...SPECT or PET imaging. The purpose of this study was to characterize its in vitro and in vivo binding properties.
In vitro binding studies using 125IR(+)-FIDA2 were performed in Sf9 cells expressing dopamine D2 or D3 receptors and in rat basal forebrain homogenates, which contain a high density of dopamine D2-like receptors. A series of in vivo SPECT imaging studies in nonhuman primates (cynomologous monkeys) were performed by intravenously injecting 7.1 +/- 1.0 mCi of 123IR(+)-FIDA2. At least one control study and one displacement experiment, in which a cold compound was injected intravenously 90 min after tracer injection, was performed in each monkey. Data were acquired in 10-min frames for 180 min, and the activity in regions of interest (basal ganglia and cerebellum) were plotted versus time.
Iodine-125-R(+)-FIDA2 displayed Kd values for D2 and D3 receptor subtypes expressed in Sf9 cells of 0.11 and 0.04 nM, respectively. As expected, SPECT images of monkey brain (transaxial sections, 2 mm) showed that the radioactivity was localized in the area of the basal ganglia and reached peak concentrations in 11.5 +/- 5.8 min postinjection. An injection of R(+)7-OH-PIPAT, a new ligand that is selective for dopamine D3 receptors and the high affinity state of dopamine D2 receptors, did not show significant displacement of 123IR(+)-FIDA2 binding in the basal ganglia.
These studies indicate that R(+)-FIDA2 may be a useful ligand for in vitro pharmacological characterization and in vivo imaging of CNS dopamine D2-like receptors.
Data-intensive science communities are progressively adopting FAIR practices that enhance the visibility of scientific breakthroughs and enable reuse. At the core of this movement, research objects ...contain and describe scientific information and resources in a way compliant with the FAIR principles and sustain the development of key infrastructure and tools. This paper provides an account of the challenges, experiences and solutions involved in the adoption of FAIR around research objects over several Earth Science disciplines. During this journey, our work has been comprehensive, with outcomes including: an extended research object model adapted to the needs of earth scientists; the provisioning of digital object identifiers (DOI) to enable persistent identification and to give due credit to authors; the generation of content-based, semantically rich, research object metadata through natural language processing, enhancing visibility and reuse through recommendation systems and third-party search engines; and various types of checklists that provide a compact representation of research object quality as a key enabler of scientific reuse. All these results have been integrated in ROHub, a platform that provides research object management functionality to a wealth of applications and interfaces across different scientific communities. To monitor and quantify the community uptake of research objects, we have defined indicators and obtained measures via ROHub that are also discussed herein.
We discuss in depth the validity and limitations of a theoretical scheme to evaluate photo-electron spectra (PES) through collecting the phase oscillations at a given measuring point. Problems appear ...if the laser pulse is still active when the first bunches of outgoing flow reach the measuring point. This limits the simple scheme for evaluation of PES to low and moderate laser intensities. Using a model of free particle plus dipole field, we develop a generalized scheme which is shown to considerably improve the results for high intensities.
Trajectory surface hopping (TSH) is one of the most widely used quantum-classical algorithms for nonadiabatic molecular dynamics. Despite its empirical effectiveness and popularity, a rigorous ...derivation of TSH as the classical limit of a combined quantum electron-nuclear dynamics is still missing. In this work we aim to elucidate the theoretical basis for the widely used hopping rules. Naturally, we concentrate thereby on the formal aspects of the TSH. Using a Gaussian wave packet limit, we derive the transition rates governing the hopping process at a simple avoided level crossing. In this derivation, which gives insight into the physics underlying the hopping process, some essential features of the standard TSH algorithm are retrieved, namely i) non-zero electronic transition rate ("hopping probability") at avoided crossings; ii) rescaling of the nuclear velocities to conserve total energy; iii) electronic transition rates linear in the nonadiabatic coupling vectors. The well-known Landau-Zener model is then used for illustration.
