| 1. |
- Egeblad, Louise, et al.
(författare)
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Structural and functional studies of the human phosphoribosyltransferase domain containing protein 1
- 2010
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Ingår i: The FEBS Journal. - : Wiley. - 1742-464X .- 1742-4658. ; 277:23, s. 4920-30
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Tidskriftsartikel (refereegranskat)abstract
- Human hypoxanthine-guanine phosphoribosyltransferase (HPRT) (EC 2.4.2.8) catalyzes the conversion of hypoxanthine and guanine to their respective nucleoside monophosphates. Human HPRT deficiency as a result of genetic mutations is linked to both Lesch-Nyhan disease and gout. In the present study, we have characterized phosphoribosyltransferase domain containing protein 1 (PRTFDC1), a human HPRT homolog of unknown function. The PRTFDC1 structure has been determined at 1.7 Å resolution with bound GMP. The overall structure and GMP binding mode are very similar to that observed for HPRT. Using a thermal-melt assay, a nucleotide metabolome library was screened against PRTFDC1 and revealed that hypoxanthine and guanine specifically interacted with the enzyme. It was subsequently confirmed that PRTFDC1 could convert these two bases into their corresponding nucleoside monophosphate. However, the catalytic efficiency (k(cat)/K(m)) of PRTFDC1 towards hypoxanthine and guanine was only 0.26% and 0.09%, respectively, of that of HPRT. This low activity could be explained by the fact that PRTFDC1 has a Gly in the position of the proposed catalytic Asp of HPRT. In PRTFDC1, a water molecule at the position of the aspartic acid side chain position in HPRT might be responsible for the low activity observed by acting as a weak base. The data obtained in the present study indicate that PRTFDC1 does not have a direct catalytic role in the nucleotide salvage pathway.
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| 2. |
- Lustig, Tova, et al.
(författare)
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Möjligheter och utmaningar med avfallsplan och avfallsförebyggande program : En utvärdering av den nationella avfallsplanen och det avfallsförebyggande programmet – Att göra mer med mindre
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Sverige har haft en nationell avfallsplan sedan 2005 och den nuvarande avfallsplanen och avfallsförebyggande programmet Att göra mer med mindre, sträcker sig över 2018 – 2023 och är framtagen av Naturvårdsverket. Både plan och program ska utvärderas vart sjätte år och ses över vid behov. I denna rapport utvärderas nuvarande avfallsplan och avfallsförebyggande program. Syftet är att bedöma vilka effekter som plan och program har bidragit till. För att bedöma detta har samtligakommunala avfallsplaner undersökts. 30 intervjuer med berörda aktörer hargenomförts samt en uppföljning av den statistik som presenterades i avfallsplanen har gjorts.Det är svårt att påvisa någon effekt av plan och program. Utvärderingen visar att planen och programmet inte har haft någon större betydelse för aktörernas arbete för en mer resurseffektiv avfallshantering. Majoriteten av de aktörer som intervjuats anger att de sällan eller aldrig använder avfallsplanen i sitt arbete. Dock nämns det av flertalet aktörer att den är bra som en handbok kring hur avfallshanteringen fungerar i Sverige om ändock något inaktuell i dagsläget. Kommunerna har ofta med de prioriterade områdena som nämns i planen menhar inte haft någon större nytta av planen i sitt arbete med att ta fram kommunala avfallsplaner. I 65 procent av de kommunala avfallsplaner som antagits från år2018 och framåt, nämns den nationella avfallsplanen. Samtidigt anges att den nationella avfallsplanen fungerar som ett medel för att visa för företagsledning och politiker vad man ska prioritera samt var utvecklingen är på väg vilket kan indikera om man är inne på rätt spår. Kännedomen om den nationella avfallsplanen är större än det avfallsförebyggande programmet.Flertalet åtgärder utförs av aktörerna som har koppling till avfallsplan och program men de utförs inte på grund av dessa utan snarare indirekt. Det finns en efterfrågan på åtgärdsförslag och goda exempel på vad man kan göra. Nu visarplanen vad man vill men inte hur man når dit. Särskilt viktigt är åtgärdsförslag för mindre kommuner och organisationer. De flesta anger att det är rätt områden som är prioriterade, men det finns dock en önskan om än mer fokus på förebyggande samt ett avsnitt kring avfall i krissituationer i en uppdaterad plan.En sammanställning av statistik för avfallsmängder år 2020 presenteras i denna rapport för att visa på utvecklingen jämfört med mängder för år 2014.Vidare är den prognos som presenterades för år 2020, vilken redovisades i den nationella avfallsplanen, inkluderad i rapporten. Statistiken visar att textilavfall och batteriavfall har ökat mest fram till år 2020 jämfört med år 2014.I framtida versioner av avfallsplanen vill aktörerna se ett dokument som är tydligare med bilagor för mer information. Ett dokument som visar vilka målen är och varför de finns samt förslag på hur man kan uppnå målen. Det efterfrågas också att planen kopplar till vad andra organisationer gör, vilka initiativ man som läsare kan ansluta sig till. Ett annat önskemål är särskilda dokument riktade motföretag eller prioriterat områden. För kategorin företag är det inte många som enbart har avfallsfrågan på sitt bord. Det är en uppgift bland många andra som en miljö- och kvalitetsansvarig har att hantera. Därför är det viktigt att lyfta frågan högre upp i avfallshierarkin för att visa vad man kan göra för att förebygga avfall. Många kommuner har exempelvisändrat namnet på sin avfallsplan till kretsloppsplan eller resursplan, för att vidga begreppet och förståelsen för det stora område som en kommunal avfallsplan ska täcka. Det kan inkludera allt från inköp och hantering, men även hur det avfall som uppstår ska hanteras. Detsamma gäller för den nationella avfallsplanen som troligen förlorar en del läsare som skulle kunna ha nytta av innehållet i planen men som inte anser sig arbeta med avfall. Kommunikationen kring den nationella avfallsplanen är därför av stor vikt och att den anpassas till olika aktörer.Utvärderingen drar slutsatsen att en handlingsplan som visar exempel på hur man kan nå målen vore önskvärt. För att hålla dokumenten aktuella bör Naturvårdsverket vid möten med aktörer återkoppla hur detta berör avfallsplanen.
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| 3. |
- Eriksson K., Susanna, et al.
(författare)
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Geometrical and energetical structural changes in organic dyes for dye-sensitized solar cells probed using photoelectron spectroscopy and DFT
- 2016
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 18:1, s. 252-260
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Tidskriftsartikel (refereegranskat)abstract
- The effects of alkoxy chain length in triarylamine based donor acceptor organic dyes are investigated with respect to the electronic and molecular surface structures on the performance of solar cells and the electron lifetime. The dyes were investigated when adsorbed on TiO2 in a configuration that can be used for dye sensitized solar cells (DSCs). Specifically, the two dyes D35 and D45 were compared using photoelectron spectroscopy (PES) and density functional theory (DFT) calculations. The differences in solar cell characteristics when longer alkoxy chains are introduced in the dye donor unit are attributed to geometrical changes in dye packing while only minor differences were observed in the electronic structure. A higher dye load was observed for D45 on TiO2. However, D35 based solar cells result in higher photocurrent although the dye load is lower. This is explained by different geometrical structures of the dyes on the surface.
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| 4. |
- Lindström, Anton, 1976-, et al.
(författare)
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Postprocessing of docked protein-ligand complexes using implicit solvation models
- 2011
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Ingår i: Journal of chemical information and modeling. - : American Chemical Society (ACS). - 1549-960X .- 1549-9596. ; 51:2, s. 267-282
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Tidskriftsartikel (refereegranskat)abstract
- Molecular docking plays an important role in drug discovery as a tool for the structure-based design of small organic ligands for macromolecules. Possible applications of docking are identification of the bioactive conformation of a protein−ligand complex and the ranking of different ligands with respect to their strength of binding to a particular target. We have investigated the effect of implicit water on the postprocessing of binding poses generated by molecular docking using MM-PB/GB-SA (molecular mechanics Poisson−Boltzmann and generalized Born surface area) methodology. The investigation was divided into three parts: geometry optimization, pose selection, and estimation of the relative binding energies of docked protein−ligand complexes. Appropriate geometry optimization afforded more accurate binding poses for 20% of the complexes investigated. The time required for this step was greatly reduced by minimizing the energy of the binding site using GB solvation models rather than minimizing the entire complex using the PB model. By optimizing the geometries of docking poses using the GBHCT+SA model then calculating their free energies of binding using the PB implicit solvent model, binding poses similar to those observed in crystal structures were obtained. Rescoring of these poses according to their calculated binding energies resulted in improved correlations with experimental binding data. These correlations could be further improved by applying the postprocessing to several of the most highly ranked poses rather than focusing exclusively on the top-scored pose. The postprocessing protocol was successfully applied to the analysis of a set of Factor Xa inhibitors and a set of glycopeptide ligands for the class II major histocompatibility complex (MHC) Aq protein. These results indicate that the protocol for the postprocessing of docked protein−ligand complexes developed in this paper may be generally useful for structure-based design in drug discovery.
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| 5. |
- Raudsepp, Urmas, et al.
(författare)
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Shipborne nutrient dynamics and impact on the eutrophication in the Baltic Sea
- 2019
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 671, s. 189-207
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Tidskriftsartikel (refereegranskat)abstract
- The Baltic Sea is a severely eutrophicated sea-area where intense shipping as an additional nutrient source is a potential contributor to changes in the ecosystem. The impact of the two most important shipborne nutrients, nitrogen and phosphorus, on the overall nutrient-phytoplankton-oxygen dynamics in the Baltic Sea was determined by using the coupled physical and biogeochemical model system General Estuarine Transport Model–Ecological Regional Ocean Model (GETM-ERGOM) in a cascade with the Ship Traffic Emission Assessment Model (STEAM) and the Community Multiscale Air Quality (CMAQ) model. We compared two nutrient scenarios in the Baltic Sea: with (SHIP) and without nutrient input from ships (NOSHIP). The model uses the combined nutrient input from shipping-related waste streams and atmospheric depositions originating from the ship emission and calculates the effect of excess nutrients on the overall biogeochemical cycle, primary production, detritus formation and nutrient flows. The shipping contribution is about 0.3% of the total phosphorus and 1.25–3.3% of the total nitrogen input to the Baltic Sea, but their impact to the different biogeochemical variables is up to 10%. Excess nitrogen entering the N-limited system of the Baltic Sea slightly alters certain pathways: cyanobacteria growth is compromised due to extra nitrogen available for other functional groups while the biomass of diatoms and especially flagellates increases due to the excess of the limiting nutrient. In terms of the Baltic Sea ecosystem functioning, continuous input of ship-borne nitrogen is compensated by steady decrease of nitrogen fixation and increase of denitrification, which results in stationary level of total nitrogen content in the water. Ship-borne phosphorus input results in a decrease of phosphate content in the water and increase of phosphorus binding to sediments. Oxygen content in the water decreases, but reaches stationary state eventually.
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| 6. |
- Bengtsson, Andreas, 1991, et al.
(författare)
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Improved Success Probability with Greater Circuit Depth for the Quantum Approximate Optimization Algorithm
- 2020
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Ingår i: Physical Review Applied. - 2331-7019. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- Present-day, noisy, small or intermediate-scale quantum processors-although far from fault tolerant-support the execution of heuristic quantum algorithms, which might enable a quantum advantage, for example, when applied to combinatorial optimization problems. On small-scale quantum processors, validations of such algorithms serve as important technology demonstrators. We implement the quantum approximate optimization algorithm on our hardware platform, consisting of two superconducting transmon qubits and one parametrically modulated coupler. We solve small instances of the NP (nondeterministic polynomial time)-complete exact-cover problem, with 96.6% success probability, by iterating the algorithm up to level two.
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| 7. |
- Morfeldt, Johannes, 1983, et al.
(författare)
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Emission pathways and mitigation options for achieving consumption-based climate targets in Sweden
- 2023
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Ingår i: Communications Earth & Environment. - Göteborg : IVL Svenska Miljöinstitutet AB. - 2662-4435. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- National emission reduction targets under the Paris Agreement have a territorial focus, incentivizing mitigation actions domestically. Here we examine the theoretical basis for adopting complementary consumption-based net-zero emission targets and assess the consequences of adopting such proposed targets for Sweden. We apply scenario analyses based on a prospective lifecycle assessment framework. The framework is a hybrid of bottom-up simulations for passenger travel, construction and housing, and food, and top-down analyses for remaining consumption. In this work, we show how consumption-based climate targets may accentuate the need for new demand-side climate policies that contribute to reducing emissions along supply chains of products and services.Our scenario analysis suggests that combining advanced mitigation technologies with behavioral changes could reduce emissions from 9.8 tons of carbon dioxide equivalents per capita in 2019 to between 2.7 and 4.8 tons by 2045 for Swedish residents, depending on global decarbonization pathways. Combining advanced mitigation technologies with behavioural changes could achieve the lowest carbon emissions per capita in Sweden, suggest scenario analyses combining bottom-up simulations for passenger travel, construction and housing, and food, and top-down analyses for remaining consumption.
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| 8. |
- Gustafsson, Mats, 1966-, et al.
(författare)
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Road dust load dynamics and influencing factors for six winter seasons in Stockholm, Sweden
- 2019
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Ingår i: Atmospheric Environment: X. - : Elsevier BV. - 2590-1621.
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Tidskriftsartikel (refereegranskat)abstract
- Traffic related non-exhaust particulate sources and road dust are an increasingly important source for PM10 air pollution as exhaust sources are decreasing due to regulations. In the Nordic countries, the road dust problem is enhanced by use of studded tyres, causing increased road wear and winter road maintenance including gritting. Efforts to reduce road dust emissions requires knowledge on temporal and spatial road dust load dynamics. The city of Stockholm, Sweden, has therefore financed seasonal (October to May) road dust sampling to be able to optimize their winter and spring time street operation measures for reduced road dust emissions. This work describes the outcome of six seasons (2011/2012–2016/2017) of road dust sampling in five central streets using the VTI wet dust sampler (WDS).The results show that road dust load, expressed as DL180 (dust load smaller than 180 μm) has a seasonal variation with the highest loads (up to 200 g/m2) in late winter and early spring and a minimum (down to about 15 g/m2) in early autumn and late spring. The dust load varies between streets and is depending on pavement surface properties. On a smaller scale the dust load has a high variability across streets due to differences in rates of suspension from different parts of the road surface, with low amounts in wheel tracks and higher in-between and outside the tracks. Between 2 and 30% of the DL180 is smaller than 10 μm and could directly contribute to PM10 emissions. In general, higher road surface texture leads to higher dust loads, but the condition of the pavement (e.g. cracks, aggregate loss) might also have an effect. A new, wear resistant pavement accumulated markedly higher road dust amounts than a several years old pavement. This paper closes with a discussion on the complex relation between road dust load and PM10 concentrations and a discussion on the challenges and comparability of road dust sampling techniques and measures.
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| 9. |
- Jalkanen, Jukka-Pekka, et al.
(författare)
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Modelling of discharges from Baltic Sea shipping
- 2021
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Ingår i: Ocean Science. - : Copernicus GmbH. - 1812-0784 .- 1812-0792.
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the new developments of the Ship Traffic Emission Assessment Model (STEAM) which enable the modelling of pollutant discharges to water from ships. These include nutrients from black/grey water discharges as well as from food waste. Further, the modelling of contaminants in ballast, black, grey and scrubber water, bilge discharges, and stern tube oil leaks are also described as well as releases of contaminants from antifouling paints.Each of the discharges is regulated by different sections of the IMO MARPOL convention, and emission patterns of different pollution releases vary significantly. The discharge patterns and total amounts for the year 2012 in the Baltic Sea area are reported and open-loop SOx scrubbing effluent was found to be the second-largest pollutant stream by volume. The scrubber discharges have increased significantly in recent years, and their environmental impacts need to be investigated in detail.
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| 10. |
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