| 1. |
- Davidsson, Peter, et al.
(författare)
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Analysis of sound transmission loss of double-leaf walls in the low-frequency range using the finite element method
- 2004
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Ingår i: Building Acoustics. - : SAGE Publications. - 1351-010X .- 2059-8025. ; 11:4, s. 239-257
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Tidskriftsartikel (refereegranskat)abstract
- The sound transmission loss of double walls in the low-frequency range is studied by means of structure-acoustic finite element analysis. The analysis simulates standard experiments to determine sound transmission loss of walls. The model is a detailed description of the geometry of the system, including both the double wall and the rooms acoustically coupled to the wall. The frequency range studied is in the 1/3-octave bands between 40 Hz and 200 Hz. A parametric study is performed to investigate the influence on the sound transmission loss of various material and geometric properties of the wall and the dimensions of the connecting rooms. The model confirms the importance of primary structural resonance and the size of the connecting rooms in determining the degree of sound transmission loss. The primary structural resonance is mainly determined by the distance between the wall studs and the properties of the sheeting material. Wall length is also important; if the length is such that the wall studs of the last wall cavity are closer together than those of the other wall cavities, the primary structural resonance will be at a higher frequency, thereby decreasing sound transmission loss over a broader frequency range. Similar dimensions of the connecting rooms results in poor transmission loss, mainly at frequencies below 100 Hz (for the wall and room dimensions studied here).
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| 2. |
- Bergamaschi, Peter, et al.
(författare)
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European Obspack compilation of atmospheric carbon dioxide data from ICOS and non-ICOS European stations for the period 1972-2023; : obspack_co2_466_GLOBALVIEWplus_v8.0_2023-04-26
- 2023
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This data package contains high accuracy CO2 dry air mole fractions from 58 ICOS and non-ICOS European observatories at in total 132 observation levels, collected by the ICOS Atmosphere Thematic Centre (ATC) and provided by the station contributors. The package is part of the Globalviewplus v8.0 data product, released in 2022 and is intended for use in carbon cycle inverse modeling, model evaluation, and satellite validation studies. Please report errors and send comments regarding this product to the ObsPack originators. Please read carefully the ObsPack Fair Use statement and cite appropriately. This is the sixth release of the GLOBALVIEWplus (GV+) cooperative data product. Please review the release notes for this product at www.esrl.noaa.gov/gmd/ccgg/obspack/release_notes.html. Metadata for this product are available at https://commons.datacite.org/doi.org/10.18160/CEC4-CAGK. Please visit http://www.gml.noaa.gov/ccgg/obspack/ for more information.
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| 3. |
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| 4. |
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| 5. |
- Brunskog, Jonas, et al.
(författare)
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Measurement of the Acoustic properties of resilient, statically tensile loaded devices in light weight structures: A measurement method and statistical analysis
- 2002
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Ingår i: Building Acoustics. ; 9:2, s. 99-137
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Tidskriftsartikel (refereegranskat)abstract
- Resilient devices are commonly used in lightweight structures to decrease sound transmission in a broad frequency band. Applications of such devices may be found in e.g. resilient mounted ceilings in aeroplanes, ships and buildings. A measurement method to characterise the frequency dependency of the transfer stiffness and the input stiffness of the resilient device is presented. The mechanical characteristics of the measurement method are investigated. In addition, some resilient devices used in buildings are analysed with respect to acoustic properties. Parameters such as static load and mountings for the devices are considered and handled by means of statistical analysis.
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| 6. |
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| 7. |
- Brunskog, Jonas, et al.
(författare)
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Prediction model for the impact sound level of lightweight floors
- 2003
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Ingår i: Acta Acustica united with Acustica. - 1436-7947. ; 89:2, s. 309-322
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Tidskriftsartikel (refereegranskat)abstract
- Lightweight floors are often troubled by poor impact-sound insulation. In order to develop and explain structures with acceptable insulation, a deterministic prediction model was developed. The paper considers transmission through the system and the response of the model. Excitation (as caused by the ISO-tapping machine) is considered in a separate paper [1]. The system description employs a spatial transform technique, making use of the periodicity of the floor structure with the aid of Poisson's sum rule. The radiated power is calculated using numerical integration in the wave-number domain, the radiated power enabling the impact sound level to be calculated. Comparisons are made between measurements found in the literature and the proposed prediction model, the effects of different excitation models being discussed. A relatively close agreement is achieved, especially if an elaborate excitation model is employed.
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| 8. |
- Brunskog, Jonas, et al.
(författare)
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Rigid indenter excitation of plates
- 2003
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Ingår i: Acta Acustica united with Acustica. - 1436-7947. ; 89:3, s. 460-470
-
Tidskriftsartikel (refereegranskat)abstract
- The paper presents expressions for the point mobility of infinite plates driven by a completely rigid indenter. The problem is of general interest in connection with the excitation and transmission of structure-borne sound. The indenter is assumed to be circular, weightless, and stiff compared with the plate. A rigid indenter is assumed to provide a better approximation of the actual situation than a soft indenter would, e.g when a hammer acts on a wooden plate. A detailed three-dimensional analysis is performed. Traditionally, the problem is solved in approximate terms by assuming a pressure distribution at the interface between the indenter and the plate. In the present study, a pressure distribution is also assumed, an optimal choice of the pressure amplitude being found by means of a variational formulation. Numerical results are presented and discussed, the discrepancy between the results obtained and the perfectly rigid indenter being examined.
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| 9. |
- Brunskog, Jonas, et al.
(författare)
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The interaction between the ISO tapping machine and lightweight floors
- 2003
-
Ingår i: Acta Acustica united with Acustica. - 1436-7947. ; 89:2, s. 296-308
-
Tidskriftsartikel (refereegranskat)abstract
- The ISO standard tapping machine, used as an excitation source in rating the impact-sound level of a floor structure, interacts with the floor structure during the hammer impact. Expressions for the force spectrum due to the impact are presented. The 6 dB difference at low frequencies of the force spectrum, evident in measurements, and reasons for it, are discussed. The interaction is investigated by use both of simplified lumped models and arbitrary frequency-dependent models. Local effects due to indentation near the point of impact and to global effects due to stiffeners are included in the description of the mobility involved. Numerical results are presented, where it is concluded that both the local and the global effects of the driving-point mobility are important in describing the force spectrum caused by the interaction between the tapping machine and the complex floor structure.
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| 10. |
- Cuapio, Angelica, et al.
(författare)
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NK cell frequencies, function and correlates to vaccine outcome in BNT162b2 mRNA anti-SARS-CoV-2 vaccinated healthy and immunocompromised individuals
- 2022
-
Ingår i: Molecular Medicine. - : BioMed Central (BMC). - 1076-1551 .- 1528-3658. ; 28:1
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Tidskriftsartikel (refereegranskat)abstract
- Adaptive immune responses have been studied extensively in the course of mRNA vaccination against COVID-19. Considerably fewer studies have assessed the effects on innate immune cells. Here, we characterized NK cells in healthy individuals and immunocompromised patients in the course of an anti-SARS-CoV-2 BNT162b2 mRNA prospective, open-label clinical vaccine trial. See trial registration description in notes. Results revealed preserved NK cell numbers, frequencies, subsets, phenotypes, and function as assessed through consecutive peripheral blood samplings at 0, 10, 21, and 35 days following vaccination. A positive correlation was observed between the frequency of NKG2C+ NK cells at baseline (Day 0) and anti-SARS-CoV-2 Ab titers following BNT162b2 mRNA vaccination at Day 35. The present results provide basic insights in regards to NK cells in the context of mRNA vaccination, and have relevance for future mRNA-based vaccinations against COVID-19, other viral infections, and cancer.Trial registration: The current study is based on clinical material from the COVAXID open-label, non-randomized prospective clinical trial registered at EudraCT and clinicaltrials.gov (no. 2021–000175-37). Description: https://clinicaltrials.gov/ct2/show/NCT04780659?term=2021-000175-37&draw=2&rank=1.
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| 11. |
- Davidsson, Peter, et al.
(författare)
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Sound reduction in double walls at low frequencies - A parametric study
- 2003
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Ingår i: Proceedings of the 10th International Congress on Sound and Vibration. ; , s. 4601-4608
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Konferensbidrag (refereegranskat)abstract
- The sound transmission in double walls at low frequencies is studied using a detailed geometric model, based on FEM. The model simulates the experiments carried out to determine the sound reduction index of the wall. The wall properties effect on the sound transmission loss is investigated and also how the sound reduction is affected by the dimensions of the connecting rooms.
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| 12. |
- Dupret, Vincent, et al.
(författare)
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Non-tetrapod sarcopterygians from the Valentia Slate Formation (Givetian, Devonian) of the Iveragh Peninsula, south-western Ireland: systematic reappraisal and palaeobiogeographic implications
- 2023
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Ingår i: Spanish Journal of Palaeontology. - 2255-0550 .- 2660-9568. ; 38:1, s. 37-45
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Tidskriftsartikel (refereegranskat)abstract
- The Middle Devonian (Givetian) Valentia Slate Formation in the Iveragh Peninsula, southwest Ireland, is more renowned for the second oldest record of tetrapod trackways in the world than for its heavily metamorphosed bone remains. The present study focuses on new discoveries of non-tetrapod sarcopterygian fish fossils from the Valentia Slate Formation. Micro-CT scanning technology allows a re-interpretation of a previously published acanthodian fin spine as a fanged coronoid of a probable Rhizodontida and the identification of a Dipnoi tooth plate and bone. In addition, a scale of Holoptychius is described. The presence of rhizodontids suggests Gondwanan ties, and a first northward dispersal wave of these vertebrates into Euramerica as early as middle Givetian. This hypothesis is supported by the common occurrence of the placoderm Bothriolepis in the Valentia Slate Formation.
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| 13. |
- Dupret, Vincent, et al.
(författare)
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The Bothriolepis (Placodermi, Antiarcha) material from the Valentia Slate Formation of the Iveragh Peninsula (middle Givetian, Ireland) : Morphology, evolutionary and systematic considerations, phylogenetic and palaeogeographic implications
- 2023
-
Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 18:2
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Tidskriftsartikel (refereegranskat)abstract
- Material of the antiarch placoderm Bothriolepis from the middle Givetian of the Valentia Slate Formation in Iveragh Peninsula, Ireland, is described and attributed to a new species, B. dairbhrensis sp. nov. A revision of the genus Bothriolepis is proposed, and its taxonomic content and previous phylogenetic analyses are reviewed, as well as the validity of morphologic characteristics considered important for the establishment of the genus, such as the shape of the preorbital recess of the neurocranium. A series of computerised phylogenetic analyses was performed, which reveals that our new species is the sister taxon to the Frasnian Scottish form B. gigantea. New phylogenetic and biogeographic analyses of the genus Bothriolepis together with comparisons between faunal assemblages reveal a first northward dispersal wave from Gondwana to Euramerica at the latest in the mid Givetian. Other Euramerican species of Bothriolepis seem to belong to later dispersal waves from Gondwana, non-excluding southward waves from Euramerica. Questions remain open such as the taxonomic validity and stratigraphic constraints for the most ancient forms of Bothriolepis in China, and around the highly speciose nature of the genus.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Hammer, Per, et al.
(författare)
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Vibration isolation on light weight floor
- 2002
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Ingår i: Building Acoustics. ; 9:4, s. 257-269
-
Tidskriftsartikel (refereegranskat)abstract
- A theoretical and experimental study of vibration isolation for a source on a lightweight floor structure is presented. The effectiveness of one-stage and two-stage isolator systems is studied. Approximate formulae are presented for both low and high frequency for the receiver, the floor structure. For the mobility, a comparison between approximate formulae, numerical exact results and experimental results are presented. The low frequency asymptote for the approximate mobility is valid up to l/p 1/4. The high frequency asymptote is valid from l/p 1/2. A straight line can be drawn between these two points for the intermediate range 1/4 < l/p < 1/2. Finally, a case study is presented. A fan is mounted on a wooden joist floor. The effect of both one and two stage isolation is demonstrated. It is clearly seen that the high mobility situation for the receiver is increased by adding a rigid body to the mount. Hence, in the frequency range of interest, the 'receiver' acts more or less as a blocked termination. A two-stage isolator almost completely eliminates the structure borne sound and compared to a one-stage isolator it reduces the sound by 20 dB at the rpm for the fan.
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| 18. |
- Hammer, Stephan C., et al.
(författare)
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Squalene hopene cyclases : highly promiscuous and evolvable catalysts for stereoselective CC and CX bond formation
- 2013
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Ingår i: Current opinion in chemical biology. - : Elsevier. - 1367-5931 .- 1879-0402. ; 17:2, s. 293-300
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Tidskriftsartikel (refereegranskat)abstract
- A review. We review here how the inherent promiscuous nature, as well as the evolvability of terpene cyclase enzymes enables new applications in chem. We mainly focus on squalene hopene cyclases, class II triterpene synthases that use a proton-initiated cationic polycyclization cascade to form carbopolycyclic products. We highlight recent findings to demonstrate that these enzymes are capable of activating different functionalities other than the traditional terminal isoprene CC-group as well as being compatible with a wide range of nucleophiles beyond the 'ene-functionality'. Thus, squalene hopene cyclases demonstrate a great potential to be used as a toolbox for general Bronsted acid catalysis.
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| 19. |
- Hammer, Stephan C., et al.
(författare)
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Stereoselective Friedel-Crafts alkylation catalyzed by squalene hopene cyclases
- 2012
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Ingår i: Tetrahedron. - : Elsevier Ltd.. - 0040-4020 .- 1464-5416. ; 68:Copyright (C) 2013 American Chemical Society (ACS). All Rights Reserved., s. 7624-7629
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Tidskriftsartikel (refereegranskat)abstract
- In org. synthesis the Friedel-Crafts alkylation is of eminent importance, as it is a key reaction in many synthetic routes. A general access to enzymic Friedel-Crafts alkylations would be very beneficial due to the high selectivity of biocatalysts. We used designed polyprenyl Ph ethers to specifically address this reaction by using squalene hopene cyclases as catalysts. Polycyclic products with arom. rings constituting important biol. active compds. were obtained. Our results demonstrate that squalene hopene cyclases can be utilized for Friedel-Crafts alkylations and reveal the potential of these enzymes for chiral Bronsted acid catalysis.
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| 20. |
- Hammer, Stephan, et al.
(författare)
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Substrate Pre-Folding and Water Molecule Organization Matters for Terpene Cyclase Catalyzed Conversion of Unnatural Substrates
- 2016
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Ingår i: ChemistrySelect. - : Wiley. - 2365-6549. ; 1, s. 3589-3593
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Tidskriftsartikel (refereegranskat)abstract
- Terpene cyclase enzymes have recently been challenged with terpene substrate derivatives to generate additional chemical complexity beyond to what is currently found in nature. Herein, molecular dynamics and biocatalysis are used to shed light on the flexibility and inherent limitation of a triterpene cyclase in converting unnatural substrates. Our studies suggest that populating binding modes which allows for concerted reaction pathways is a key element towards an expanded substrate scope and new chemistries displayed by terpene cyclases. Additionally, we show that the spatial organization of water, which is influenced by both the substrate architecture as well as the active site geometry, controls the product selectivity. This highlights that activity and selectivity displayed by terpene cyclases acting on unnatural substrates is particularly difficult to predict, since they depend on various parameters.
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| 21. |
- Holmberg, Dag, et al.
(författare)
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Absorption and radiation impedance of finite absorbing patches
- 2003
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Ingår i: Acta Acustica united with Acustica. - 1436-7947. ; 89:3, s. 406-415
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Tidskriftsartikel (refereegranskat)abstract
- A variational formulation is used to calculate the sound absorption in order to incorporate the interaction between several absorbing patches of arbitrary shape. In particular, this formulation is applied to small periodic patches. The absorption characteristics are governed by the radiation impedance, Z(r), which is a function of the absorber's geometry and the incidence angle, together with the surface impedance of the absorber. The behaviour of Z(r) is evaluated numerically for a number of typical configurations, and the effect on the statistical absorption coefficient, alpha(stat) is calculated. The evaluations stress that alpha(stat) is regulated by the interaction between Z(r) and the impedance of the absorber. A comparison is made of results from measurements and calculations performed on the measurement set-up.
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| 22. |
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| 23. |
- Johansson, Ann-Charlotte, et al.
(författare)
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Evaluation of drum sound with ISO tapping machine
- 2005
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Ingår i: Building Acoustics. - : SAGE Publications. - 1351-010X .- 2059-8025. ; 12:2, s. 59-84
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Tidskriftsartikel (refereegranskat)abstract
- A branch norm, EPLF NORM 021029-3,1 has been established for measuring drum sound on laminate floor coverings. ‘Drum sound’ refers to the sound occurring when an object, e.g. a foot, strikes the flooring in the room in which the receiving ear is located. The norm evaluates the subjective perception of the drum sound's loudness using the ISO tapping machine. A round-robin study of the norm is reported along with the results of a paired comparison listening test using the same floor coverings. The article discusses general aspects of evaluation measures, tapping machines, test environments, etc., that need to be considered when measuring drum sound on various floor coverings, such as linoleum, wood parquet and laminate. It is concluded that loudness as measured according to ISO 532B correlates the best with the subjective perception of the drum sound's loudness. The tapping machine can be used to excite hard floor coverings to produce the drum sound, but should be used with caution in studying low-level drum sounds due to the tapping machine's inherent mechanical noise.
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| 24. |
- Johansson, Ann-Charlotte, et al.
(författare)
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Prediction of subjective response from objective measurements applied to walking sound
- 2004
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Ingår i: Acta Acustica united with Acustica. - 1436-7947. ; 90:1, s. 161-170
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses prediction of the subjective response to walking sound - also called drum sound - based on differences in objective measurements. 'Walking sound' refers to the sound heard when someone is walking in the same room as the listener. Walking sound has attracted interest in recent years, particularly due to an increased use of thin floating floor constructions, such as veneer or laminate flooring, which can produce loud and sharp walking sound. A paired comparison test was performed in laboratory where listeners were asked which of the walking sounds was most disturbing. The response was analysed using a modified Bradley and Terry model allowing ties. Various measures, such as loudness according to ISO 532B, were tested against the subjective response using linear regression. The difference in 10-percentile loudness, N-10, between two stimuli was shown to predict the subjective response better than, for example, A-weighted sound pressure level. A difference of about 8% in N-10 resulted in 50% of the subjects noticing a difference. The methodology used is applicable in situations when objective measures that have subjective counterparts are sought. Although the method is based on relative observations, an absolute ranking can be obtained by using a reference or a well-defined recording situation.
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| 25. |
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| 26. |
- Macrae, Duncan J, et al.
(författare)
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Inhaled nitric oxide therapy in neonates and children: reaching a European consensus.
- 2004
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Ingår i: Intensive care medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 30:3, s. 372-80
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Tidskriftsartikel (refereegranskat)abstract
- Inhaled nitric oxide (iNO) was first used in neonatal practice in 1992 and has subsequently been used extensively in the management of neonates and children with cardiorespiratory failure. This paper assesses evidence for the use of iNO in this population as presented to a consensus meeting jointly organised by the European Society of Paediatric and Neonatal Intensive Care, the European Society of Paediatric Research and the European Society of Neonatology. Consensus Guidelines on the Use of iNO in Neonates and Children were produced following discussion of the evidence at the consensus meeting.
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| 27. |
- Melandri, A., et al.
(författare)
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GRB171010A/SN 2017htp : a GRB-SN at z=0.33
- 2019
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Ingår i: Monthly notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 490:4, s. 5366-5374
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Tidskriftsartikel (refereegranskat)abstract
- The number of supernovae known to be connected with long-duration gamma-ray bursts (GRBs) is increasing and the link between these events is no longer exclusively found at low redshift (z less than or similar to 0.3) but is well established also at larger distances. We present a new case of such a liaison at z = 0.33 between GRB171010A and SN 2017htp. It is the second closest GRB with an associated supernova of only three events detected by Fermi-LAT. The supernova is one of the few higher redshift cases where spectroscopic observations were possible and shows spectral similarities with the well-studied SN 1998bw, having produced a similar Ni mass (M-Ni = 0.33 +/- 0.02 M-circle dot) with slightly lower ejected mass (M-ej = 4.1 +/- 0.7 M-circle dot) and kinetic energy (E-K = 8.1 +/- 2.5 x 10(51) erg). The host-galaxy is bigger in size than typical GRB host galaxies, but the analysis of the region hosting the GRB revealed spectral properties typically observed in GRB hosts and showed that the progenitor of this event was located in a very bright H II region of its face-on host galaxy, at a projected distance of similar to 10 kpc from its galactic centre. The star-formation rate (SFRGRB similar to 0.2 M-circle dot yr(-1)) and metallicity (12 + log(O/H) similar to 8.15 +/- 0.10) of the GRB star-forming region are consistent with those of the host galaxies of previously studied GRB-SN systems.
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| 28. |
- Nebel, Bernd A., et al.
(författare)
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A Career in Catalysis : Bernhard Hauer
- 2023
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 13:13, s. 8861-8889
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Forskningsöversikt (refereegranskat)abstract
- On the occasion of Professor Bernhard Hauer′s (partial) retirement, we reflect on and highlight his distinguished career in biocatalysis. Bernhard, a biologist by training, has greatly influenced biocatalysis with his vision and ideas throughout his four-decade career. The development of his career went hand in hand with the evolution of biocatalysis and the application and development of enzymes for chemical processes. In this Account, we present selected examples of his early work on the development of enzymes and their application in an industrial setting, with a focus on his specific contributions to harnessing the catalytic power of enzymes for novel reactions and the understanding and engineering of flexible loops and channels on catalysis.
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| 29. |
- Pallon, Jan, et al.
(författare)
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Symbiotic fungi that are essential for plant nutrient uptake investigated with NMP
- 2007
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Ingår i: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 260:1, s. 149-152
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Tidskriftsartikel (refereegranskat)abstract
- The nuclear microprobe (NMP) technique using PIXE for elemental analysis and STIM on/off axis for parallel mass density normalization has proven successful to investigate possible interactions between minerals and ectomycorrhizal (EM) mycelia that form symbiotic associations with forest trees. The ability for the EM to make elements biologically available from minerals and soil were compared in field studies and in laboratory experiments, and molecular analysis (PCR-RFLP) was used to identify ectomycorrhizal species from the field samplings. EM rhizomorphs associated with apatite in laboratory systems and in mesh bags incubated in forest ecosystems contained larger amounts of Ca than similar rhizomorphs connected to acid-washed sand. EM mycelium produced in mesh bags had a capacity to mobilize P from apatite-amended sand and a high concentration of K in some rhizomorphs suggests that these fungi are good accumulators of K and may have a significant role in transporting K to trees. Spores formed by arbuscular mycorrhizal (AM) fungi in laboratory cultures were compared with spores formed in saline soils in Tunisia in Northern Africa. We found lower concentrations of P and higher concentrations of Cl in the spores collected from the field than in the spores collected from laboratory cultures. For the case of laboratory cultures, the distribution of e.g. P and K was found to be clearly correlated.
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| 30. |
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| 31. |
- Pucetaite, Milda, et al.
(författare)
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Shining new light into soil systems : Spectroscopy in microfluidic soil chips reveals microbial biogeochemistry
- 2021
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717. ; 153
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Tidskriftsartikel (refereegranskat)abstract
- Microfluidic soil chips render optical access to the naturally opaque soil systems and enable direct investigation of microbial growth and interactions in micro-structurally and chemically controlled environments. However, chemical analyses of these interactions at high spatial and temporal resolution are still lacking. Here we propose that the use of advanced microspectroscopy techniques, namely infrared absorption, Raman scattering and synchrotron radiation based X-ray microspectroscopy, in microfluidic soil chips would make it possible to approach these phenomena. They allow monitoring biogeochemical processes in and around soil microbial cells growing in the reproducibly designed microenvironments within the chips at (sub)micrometer scale. Complementary use of several of the microspectroscopy techniques is beneficial for obtaining information about both molecular and elemental composition, oxidation states and local structure of the elements in the sample. Ultimately, we argue that microspectroscopy in microfluidic chips can lead to relevant breakthroughs in frontier research areas in soil science, such as (1) analysis of chemical responses of microbes to environmental triggers at micro-scale spatial resolution, (2) phenotypical identification and phylogenetic classification of single cells of soil microbes in situ, (3) determining spatially and time resolved effects of heavy metals and organic pollutants, including microplastics, on soils and (4) spatially resolved analysis of soil organic matter dynamics for better understanding of soil carbon storage. Tailoring the chip design to achieve optical transparency to the radiation type used by the different microspectroscopy methods is crucial to achieve this; therefore, we expect that this perspective will inspire the scientific community to use the proposed approaches and thus push both the technical development of the microspectroscopy suitable soil chips and the research frontier in soil science.
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| 32. |
- Ramonet, M., et al.
(författare)
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The fingerprint of the summer 2018 drought in Europe on ground-based atmospheric CO 2 measurements : Atmospheric CO 2 anomaly
- 2020
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Ingår i: Philosophical Transactions of the Royal Society B: Biological Sciences. - : The Royal Society. - 0962-8436 .- 1471-2970. ; 375:1810
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Tidskriftsartikel (refereegranskat)abstract
- During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO 2) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO 2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO 2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO 2 cycles from 48 European stations were available for 2017 and 2018. Earlier data were retrieved for comparison from international databases or national networks. Here, we show that the usual summer minimum in CO 2 due to the surface carbon uptake was reduced by 1.4 ppm in 2018 for the 10 stations located in the area most affected by the temperature anomaly, mostly in Northern Europe. Notwithstanding, the CO 2 transition phases before and after July were slower in 2018 compared to 2017, suggesting an extension of the growing season, with either continued CO 2 uptake by photosynthesis and/or a reduction in respiration driven by the depletion of substrate for respiration inherited from the previous months due to the drought. For stations with sufficiently long time series, the CO 2 anomaly observed in 2018 was compared to previous European droughts in 2003 and 2015. Considering the areas most affected by the temperature anomalies, we found a higher CO 2 anomaly in 2003 (+3 ppm averaged over 4 sites), and a smaller anomaly in 2015 (+1 ppm averaged over 11 sites) compared to 2018. This article is part of the theme issue 'Impacts of the 2018 severe drought and heatwave in Europe: from site to continental scale'.
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| 33. |
- Scarpellini, E., et al.
(författare)
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International consensus on the diagnosis and management of dumping syndrome
- 2020
-
Ingår i: Nature Reviews Endocrinology. - : Springer Science and Business Media LLC. - 1759-5029 .- 1759-5037. ; 16:8, s. 448-466
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Tidskriftsartikel (refereegranskat)abstract
- Dumping syndrome is a common but underdiagnosed complication of gastric and oesophageal surgery. We initiated a Delphi consensus process with international multidisciplinary experts. We defined the scope, proposed statements and searched electronic databases to survey the literature. Eighteen experts participated in the literature summary and voting process evaluating 62 statements. We evaluated the quality of evidence using grading of recommendations assessment, development and evaluation (GRADE) criteria. Consensus (defined as >80% agreement) was reached for 33 of 62 statements, including the definition and symptom profile of dumping syndrome and its effect on quality of life. The panel agreed on the pathophysiological relevance of rapid passage of nutrients to the small bowel, on the role of decreased gastric volume capacity and release of glucagon-like peptide 1. Symptom recognition is crucial, and the modified oral glucose tolerance test, but not gastric emptying testing, is useful for diagnosis. An increase in haematocrit >3% or in pulse rate >10 bpm 30 min after the start of the glucose intake are diagnostic of early dumping syndrome, and a nadir hypoglycaemia level <50 mg/dl is diagnostic of late dumping syndrome. Dietary adjustment is the agreed first treatment step; acarbose is effective for late dumping syndrome symptoms and somatostatin analogues are preferred for patients who do not respond to diet adjustments and acarbose. Dumping syndrome is a frequent complication of oesophageal and gastric surgery, as well as bariatric surgery; however, guidance on how to manage patients with this condition is lacking. In this Evidence-based guideline, the authors use a Delphi consensus process to develop uniform guidance for the definition, diagnosis and management of dumping syndrome.
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| 34. |
- Syrén, Per-Olof, et al.
(författare)
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Entropy is Key to the Formation of Pentacyclic Terpenoids by Enzyme-Catalyzed Polycyclization
- 2014
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 53:19, s. 4845-4849
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Tidskriftsartikel (refereegranskat)abstract
- Polycyclizations constitute a cornerstone of chemistry and biology. Multicyclic scaffolds are generated by terpene cyclase enzymes in nature through a carbocationic polycyclization cascade of a prefolded polyisoprene backbone, for which electrostatic stabilization of transient carbocationic species is believed to drive catalysis. Computational studies and site-directed mutagenesis were used to assess the contribution of entropy to the polycyclization cascade catalyzed by the triterpene cyclase from A. acidocaldarius. Our results show that entropy contributes significantly to the rate enhancement through the release of water molecules through specific channels. A single rational point mutation that results in the disruption of one of these water channels decreased the entropic contribution to catalysis by 60kcalmol(-1). This work demonstrates that entropy is the key to enzyme-catalyzed polycyclizations, which are highly relevant in biology since 90% of all natural products contain a cyclic subunit.
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| 35. |
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| 36. |
- Wegler, Christine, et al.
(författare)
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Variability in Mass Spectrometry-based Quantification of Clinically Relevant Drug Transporters and Drug Metabolizing Enzymes
- 2017
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Ingår i: Molecular Pharmaceutics. - : AMER CHEMICAL SOC. - 1543-8384 .- 1543-8392. ; 14:9, s. 3142-3151
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Tidskriftsartikel (refereegranskat)abstract
- Many different methods are used for mass-spectrometry-based protein quantification in pharmacokinetics and systems pharmacology. It has not been established to what extent the results from these various methods are comparable. Here, we compared six different mass spectrometry-based proteomics methods by measuring the expression of clinically relevant drug transporters and metabolizing enzymes in human liver. Mean protein concentrations were in general quantified to similar levels by methods using whole tissue lysates. Methods using subcellular membrane fractionation gave incomplete enrichment of the proteins. When the enriched proteins were adjusted to levels in whole tissue lysates, they were on average 4 fold lower than those quantified directly in whole tissue lysates. The differences in protein levels were propagated into differences in predictions of hepatic clearance. In conclusion, caution is needed when comparing and applying quantitative proteomics data obtained with different methods, especially since membrane fractionation is common practice for protein quantification used in drug clearance predictions.
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| 37. |
- Weiss, Frederik, et al.
(författare)
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Direct Quantification of Cytochromes P450 and Drug Transporters-A Rapid, Targeted Mass Spectrometry-Based Immunoassay Panel for Tissues and Cell Culture Lysates
- 2018
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Ingår i: Drug Metabolism And Disposition. - : AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS. - 0090-9556 .- 1521-009X. ; 46:4, s. 387-396
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Tidskriftsartikel (refereegranskat)abstract
- The quantification of drug metabolizing enzymes and transporters has recently been revolutionized on the basis of targeted proteomic approaches. Isotope-labeled peptides are used as standards for the quantification of the corresponding proteins in enzymatically fragmented samples. However, hurdles in these approaches are low throughput and tedious sample prefractionation steps prior to mass spectrometry (MS) readout. We have developed an assay platform using sensitive and selective immunoprecipitation coupled with mass spectrometric readout allowing the quantification of proteins directly from whole cell lysates using less than 20,000 cells per analysis. Peptide group-specific antibodies (triple X proteomics antibodies) enable the enrichment of proteotypic peptides sharing a common terminus. These antibodies were employed to establish a MS-based immunoassay panel for the quantification of 14 cytochrome P450 (P450) enzymes and nine transporters. We analyzed the P450 enzyme and transporter levels in genotyped liver tissue homogenates and microsomes, and in samples from a time course induction experiment in human hepatocytes addressing different induction pathways. For the analysis of P450 enzymes and transporters only a minute amount of sample is required and no prefractionation is necessary, thus the assay platform bears the potential to bridge cell culture model experiments and results from whole organ tissue studies.
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