| 1. |
- Kumpulainen, Elina, et al.
(författare)
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Plasma and cerebrospinal fluid pharmacokinetics of flurbiprofen in children
- 2010
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley. - 0306-5251 .- 1365-2125. ; 70:4, s. 557-566
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Tidskriftsartikel (refereegranskat)abstract
- Flurbiprofen is a commonly used non-steroidal anti-inflammatory drug in children to treat pain and fever. There is limited information on the pharmacokinetics of flurbiprofen in children and no data on the cerebrospinal fluid permeation of flurbiprofen. WHAT THIS STUDY ADDS Our population pharmacokinetic model indicates that weight-based dosing of flurbiprofen is appropriate in children older than 6 months. The bioavailability of oral flurbiprofen syrup is high, 71-91%, and thus, the oral syrup provides accurate dosing in paediatric patients. Cerebrospinal fluid concentrations of flurbiprofen are markedly higher than the unbound plasma concentrations. AIMS This study was designed to characterize paediatric pharmacokinetics and central nervous system exposure of flurbiprofen. METHODS The pharmacokinetics of flurbiprofen were studied in 64 healthy children aged 3 months to 13 years, undergoing surgery with spinal anaesthesia. Children were administered preoperatively a single dose of flurbiprofen intravenously as prodrug (n = 27) or by mouth as syrup (n = 37). A single cerebrospinal fluid (CSF) sample (n = 60) was collected at the induction of anaesthesia, and plasma samples (n = 304) before, during and after the operation (up to 20 h after administration). A population pharmacokinetic model was built using the NONMEM software package. RESULTS Flurbiprofen concentrations in plasma were well described by a three compartment model. The apparent bioavailability of oral flurbiprofen syrup was 81%. The estimated clearance (CL) was 0.96 l h-1 70 kg-1. Age did not affect the clearance after weight had been included as a covariate. The estimated volume of distribution at steady state (V-ss) was 8.1 l 70 kg-1. Flurbiprofen permeated into the CSF, reaching concentrations that were seven-fold higher compared with unbound plasma concentrations. CONCLUSIONS Flurbiprofen pharmacokinetics can be described using only weight as a covariate in children above 6 months, while more research is needed in neonates and in younger infants.
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| 2. |
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| 3. |
- Luttinen, Arto, et al.
(författare)
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Age, geochemistry, and origin of the mid-Proterozoic Häme mafic dyke swarm, southern Finland
- 2022
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Ingår i: Bulletin of the Geological Society of Finland. - : The Geological Society of Finland. - 0367-5211 .- 1799-4632. ; 94, s. 75-101
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Tidskriftsartikel (refereegranskat)abstract
- We have reappraised the age and composition of the mid-Proterozoic Flame dyke swarm in southern Finland. The dominant trend of the dykes of this swarm is NW to WNW. Petrographic observations and geochemical data indicate uniform, tholeiitic low-Mg parental magmas for all of the dykes. Nevertheless, the variability in incompatible trace element ratios, such as Zr/Y and La/Nb, provides evidence of changing mantle melting conditions and variable crustal contamination. Our ID-TIMS 207Pb/206Pb ages for four low-Zr/Y-type dykes indicate emplacement at 1639 ± 3 Ma, whereas the most reliable previously published ages suggest emplacement of the high-Zr/Y-type dykes at 1642 ± 2 Ma. We propose that the Hame dyke swarm, and possibly also the other mid-Proterozoic mafic dyke swarms in southern Finland, records a progressive decrease in Zr/Y values due to magma generation under developing areas of thinned lithosphere. We consider that the formation of mafic magmas was most probably associated with the upwelling of hot convective mantle in an extensional setting possibly related to the nearby Gothian orogeny. The generation of tholeiitic magmas below continental lithosphere was probably promoted by the elevated mantle temperature underneath the Nuna supercontinent. We speculate that the origin of most of the relatively small mid-Proterozoic mafic dyke swarms, anorthosites, rapakivi granites, and associated rocks found across Nuna was similarly triggered by extensional plate tectonics and the convection of anomalous hot upper mantle below the supercontinent.
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| 4. |
- Salminen, Johanna, et al.
(författare)
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The Precambrian drift history and paleogeography of Baltica
- 2021
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Ingår i: Ancient Supercontinents and the Paleogeography of Earth. - : Elsevier. ; , s. 155-205
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Bokkapitel (refereegranskat)abstract
- We review paleomagnetic data and paleoclimatological indicators of Baltica and its subcratons. Between Neoarchean and middle Mesoproterozoic Karelia and Kola, and later the united Baltica were located mostly at the latitudes between 35°N and 35°S. Location of Baltica oscillated between high latitudes and the equator at late Mesoproterozic–Neoproterozoic. Drift velocities of the separate cratons between Neoarchean and middle Proterozoic are lower than the velocities of the united Baltica at late Paleoproterozoic–middle Mesoproterozoic. At Late Mesoproterozoic–Neoproterozoic Baltica shows high velocity peaks, which correlate temporarily with the ones obtained for Laurentia and can be ascribed to true polar wander. Increase in drift rates correlate temporarily with orogenies related to the formation of the supercontinents Nuna and Rodinia and in smaller scale to the crustal growth of Baltica. Based on the results, we review possible nearest neighbors for the Kola and Karelia in the Superia supercraton and for Baltica in the Nuna and Rodinia supercontinents.
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| 5. |
- Vuori, Leena, et al.
(författare)
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Improved corrosion properties of hot dip galvanized steel by nanomolecular silane layers as hybrid interface between zinc and top coatings
- 2017
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Ingår i: Corrosion: Journal of science and engineering. - : NACE International. - 0010-9312. ; 73:2, s. 169-180
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Tidskriftsartikel (refereegranskat)abstract
- Thin organic coatings (TOC) or paints on hot dip galvanized steel (HDGS) improve the corrosion properties and create visually pleasing surfaces. Delamination of these coatings leads to corrosion and peeling of the paints. Hence, a novel method for improved adhesion and corrosion properties for HDGS surfaces is introduced. It is shown how the fabrication of a nanomolecular silane film as an interfacial layer between the HDGS and TOC or paint improves the corrosion properties of HDGS in different pH regimes. Understanding the corrosion behavior of ultra-thin silane layers under differing pH is crucial, as subsequent coatings have different pHs. By varying the silanization parameters, two different nanomolecular surface structures of aminopropyl trimethoxysilane (APS) on HDGS were fabricated: well-ordered monolayers with approximately 1 nm thickness and highly clustered APS films with a thickness in the range of 5 nm to 8 nm. To verify the nanomolecular APS structures, photoelectron spectroscopy and contact angle measurements were used. The corrosion properties of HDGS and silanized HDGS were studied with linear sweep voltammetry and electrochemical impedance spectroscopy. It is shown that at pH 5 and 7, passivation behavior is observed on silanized samples, but the most significant improvement in corrosion resistance is found at pH 10, where the corrosion currents of silanized samples are up to two orders of magnitude lower than on uncoated metallic samples. Also, it is demonstrated that the corrosion inhibition of APS is not only dependent on the thickness of the silane film, but also the molecular ordering at the surface. The thin, well-ordered APS monolayer is more resistant toward corrosion in NaCl solution (pH 7) than thicker clustered APS layer. This indicates that the highly ordered nanomolecular surface structure protects the HDGS/silane interface from the Cl- adsorption better than the thicker, but more randomly ordered, APS layers. Nanomolecular interfacial silane films for enhanced corrosion and adhesion properties on HDGS are transferrable to industrial production lines providing a low cost and environmentally friendly method for improved HDGS products.
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| 6. |
- Välitalo, Pyry, et al.
(författare)
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Plasma and Cerebrospinal Fluid Pharmacokinetics of Naproxen in Children
- 2012
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Ingår i: Journal of clinical pharmacology. - : Wiley. - 0091-2700 .- 1552-4604. ; 52:10, s. 1516-1526
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to characterize pediatric pharmacokinetics and central nervous system exposure of naproxen after oral administration. The pharmacokinetics of naproxen was studied in 53 healthy children aged 3 months to 12 years undergoing surgery with spinal anesthesia. Children received preoperatively a single dose of 10 mg/kg oral naproxen suspension. A single cerebrospinal fluid (CSF) sample (n = 52) was collected at the induction of anesthesia, and plasma samples (n = 270) were collected before, during, and after the operation (up to 51 hours after administration). A population pharmacokinetic model was built using the NONMEM software. Naproxen concentrations in plasma were well described by a 2-compartment model. The estimated oral clearance (CL/F) was 0.62 L/h when linearly scaled by weight to 70 kg. The apparent volume of distribution at steady state (Vss/F) was 12.5 L/70 kg. The findings are consistent with previously reported pharmacokinetic parameters for children older than 5 years. Naproxen permeated into the CSF and reached CSF concentrations that were 4 times higher than unbound plasma concentrations. Based on these data, weight can be used as a basis for naproxen dosing in children older than 3 months of age.
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