| 1. |
- Elf, Patric, et al.
(författare)
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Molecular Dynamics Simulations of Cellulose and Dialcohol Cellulose under Dry and Moist Conditions
- 2023
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Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 24:6, s. 2706-2720
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Tidskriftsartikel (refereegranskat)abstract
- The development of wood-based thermoplastic polymers that can replace synthetic plastics is of high environmental importance, and previous studies have indicated that cellulose-rich fiber containing dialcohol cellulose (ring-opened cellulose) is a very promising candidate material. In this study, molecular dynamics simulations, complemented with experiments, were used to investigate how and why the degree of ring opening influences the properties of dialcohol cellulose, and how temperature and presence of water affect the material properties. Mechanical tensile properties, diffusion/mobility-related properties, densities, glass-transition temperatures, potential energies, hydrogen bonds, and free volumes were simulated for amorphous cellulosic materials with 0-100% ring opening, at ambient and high (150 °C) temperatures, with and without water. The simulations showed that the impact of ring openings, with respect to providing molecular mobility, was higher at high temperatures. This was also observed experimentally. Hence, the ring opening had the strongest beneficial effect on “processability” (reduced stiffness and strength) above the glass-transition temperature and in wet conditions. It also had the effect of lowering the glass-transition temperature. The results here showed that molecular dynamics is a valuable tool in the development of wood-based materials with optimal thermoplastic properties.
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| 2. |
- Knief, Ulrich, et al.
(författare)
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Highly pathogenic avian influenza causes mass mortality in Sandwich Tern Thalasseus sandvicensis breeding colonies across north-western Europe
- 2024
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Ingår i: Bird conservation international. - : Cambridge University Press. - 0959-2709 .- 1474-0001. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- In 2022, highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b became enzootic and caused mass mortality in Sandwich TernThalasseus sandvicensis and other seabird species across north-western Europe. We present data on the characteristics of the spread of the virus between and within breeding colonies and the number of dead adult Sandwich Terns recorded at breeding sites throughout north-western Europe. Within two months of the first reported mortalities, 20,531 adult Sandwich Terns were found dead, which is >17% of the total north-western European breeding population. This is probably an under-representation of total mortality, as many carcasses are likely to have gone unnoticed and unreported. Within affected colonies, almost all chicks died. After the peak of the outbreak, in a colony established by late breeders, 25.7% of tested adults showed immunity to HPAI subtype H5. Removal of carcasses was associated with lower levels of mortality at affected colonies. More research on the sources and modes of transmission, incubation times, effective containment, and immunity is urgently needed to combat this major threat for colonial seabirds.
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| 3. |
- Molia, Anne, et al.
(författare)
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Elaphomyces section Elaphomyces (Eurotiales, Ascomycota) — taxonomy and phylogeny of North European taxa, with the introduction of three new species
- 2020
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Ingår i: Fungal Systematics and Evolution. - : Westerdijk Fungal Biodiversity Institute. - 2589-3823 .- 2589-3831. ; 5, s. 283-300
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Tidskriftsartikel (refereegranskat)abstract
- The North European species of Elaphomyces section Elaphomyces (Eurotiales, Pezizomycotina) are studied. Three new species, E. citrinopapillatus, E. pusillus, and E. roseoviolaceus are introduced and verified by morphology and sequence data from ITS, nuclear LSU, mitochondrial SSU, and β-tubulin. A lectotype for Elaphomyces granulatus is selected. Elaphomyces granulatus and E. muricatus are epitypified with sequenced material from the Femsjö region in South Sweden. Elaphomyces striatosporus is epitypified with sequenced material from the vicinity of the type locality in Norway. A key to all species of Elaphomyces occurring in Denmark, Norway, and Sweden is provided.
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| 4. |
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| 5. |
- Akhter, Tansim, 1967-, et al.
(författare)
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Dimethylarginines correlate to common carotid artery wall layer dimensions and cardiovascular risk factors in pregnant women with/without preeclampsia : A group comparative study
- 2021
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Ingår i: European Journal of Obstetrics, Gynecology, and Reproductive Biology. - : Elsevier. - 0301-2115 .- 1872-7654. ; 258, s. 288-293
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Asymmetric- and symmetric dimethylarginines (ADMA, SDMA) are elevated in cardiovascular disease (CVD). Preeclampsia is a pregnancy-specific syndrome and is an independent risk factor for subsequent CVD. Aims were to investigate whether ADMA, SDMA levels and L-arginine/ADMA and I.arginine/SDMA ratios during pregnancy and their changes from pregnancy to postpartum are associated to arterial wall layer dimensions and cardiovascular risk factors in women with and without preeclampsia. Study design: Dimethylarginines were analyzed by LC-MS, and the common-carotid-artery (CCA) intima and media thicknesses were estimated using 22-MHz non-invasive ultrasonography in women with preeclampsia (cases = 48) and normal pregnancies (controls = 58) in similar gestational age, with reassessment one-year postpartum. A thick intima, thin media and high intima/media ratio (I/M) indicates a less healthy arterial wall. Results: The median age of cases and controls was 30 years. During pregnancy, women with preeclampsia had higher plasma ADMA, SDMA and lower t-arginine/ADMA and L-arginine/SDMA (all p <0.01) than women with normal pregnancies. Further, ADMA, SDMA, L-arginine/ADMA and L-arginine/SDMA correlated to intima thickness (r(s) = 0.33/0.33/-0.33/-0.35 and p <0.01), UM (r(s) = 0.26/0.28/-0.22/-0.26 and p <0.05) and mean arterial pressure (MAP) (rs = 0.43/0.42/-0.39/-0.40 and p <0.0001). Changes in ADMA, SDMA and t-arginine/SDMA from pregnancy to postpartum correlated to changes in intima thickness (r(s) = 0.22/0.32/-0.21 and p < 0.05/<0.01/<0.05), I/M (r(s) = 0.22/0.31/0.08 and p < 0.05/<0.01/=0.43) and MAP (r(s) = 0.31/0.53/-0.25 and p < 0.01/<0.001/<0.05). No correlations were found for conventional CCA intima-media-thickness. Conclusions: Dimethylarginines were associated to signs of adverse effects on arterial wall layer dimensions and cardiovascular risk factors in women with and without preeclampsia, during pregnancy and to their changes from pregnancy up to one-year postpartum. (C) 2021 The Authors. Published by Elsevier B.V.
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| 6. |
- Akhter, Tansim, 1967-, et al.
(författare)
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Elevated Plasma Levels of Arginines During Labor Among Women with Spontaneous Preterm Birth : A Prospective Cohort Study
- 2024
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Ingår i: American Journal of Reproductive Immunology. - : John Wiley & Sons. - 1046-7408 .- 1600-0897. ; 91:6
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Tidskriftsartikel (refereegranskat)abstract
- Problem: Preterm birth (PTB) is a leading cause of infant mortality and morbidity. The pathogenesis of PTB is complex and involves many factors, including socioeconomy, inflammation and infection. Asymmetric dimethylarginine, ADMA and symmetric dimethylarginine, SDMA are involved in labor as inhibitors of nitric oxide, a known relaxant of the uterine smooth muscles. Arginines are scarcely studied in relation to PTB and we aimed to investigate arginines (ADMA, SDMA and L-arginine) in women with spontaneous PTB and term birth.Methods of the Study: The study was based on data from the population-based, prospective cohort BASIC study conducted in Uppsala County, Sweden, between September 2009 and November 2018. Arginines were analyzed by Ultra-High Performance Liquid Chromatography using plasma samples taken at the onset of labor from women with spontaneous PTB (n = 34) and term birth (n = 45). We also analyzed the inflammation markers CRP, TNF-R1 and TNF-R2 and GDF-15.Results: Women with spontaneous PTB had higher plasma levels of ADMA (p < 0.001), and L-Arginine (p = 0.03). In addition, inflammation marker, TNF-R1 (p = 0.01) was higher in spontaneous PTB compared to term birth. Further, in spontaneous PTB, no significant correlations could be observed when comparing levels of arginines with inflammation markers, except ADMA versus CRP.Conclusions: These findings provide novel evidence for the potential involvement of arginines in the pathogenesis of spontaneous PTB and it seems that arginine levels at labor vary independently of several inflammatory markers. Further research is warranted to investigate the potential of arginines as therapeutic targets in the prevention and management of spontaneous PTB.
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| 7. |
- Akhter, Tansim, 1967-, et al.
(författare)
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Plasma levels of arginines at term pregnancy in relation to mode of onset of labor and mode of childbirth
- 2023
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Ingår i: American Journal of Reproductive Immunology. - : John Wiley & Sons. - 1046-7408 .- 1600-0897. ; 90:3
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Tidskriftsartikel (refereegranskat)abstract
- PROBLEM: The exact biochemical mechanisms that initiate labor are not yet fully understood. Nitric oxide is a potent relaxant of uterine smooth muscles until labor starts, and its precursor is L-arginine. Asymmetric (ADMA) and symmetric (SDMA) dimethylarginines, are potent NO-inhibitors. However, arginines (dimethylarginines and L-arginine) are scarcely studied in relation to labor and childbirth. We aimed to investigate arginines in women with spontaneous (SLVB) and induced (ILVB) term labor with vaginal birth and in women undergoing elective caesarean section (ECS).METHOD OF STUDY: Women at gestational week 16-18 were recruited to the population-based prospective cohort study BASIC at the Uppsala University Hospital, Sweden. Plasma samples taken at start of labor were analyzed for arginines, from SLVB (n = 45), ILVB (n = 45), and ECS (n = 45), using Ultra-High Performance Liquid Chromatography. Between-group differences were assessed using Kruskal-Wallis and Mann-Whitney U-test.RESULTS: Women with SLVB and ILVB had higher levels of ADMA (p < .0001), SDMA (p < .05) and lower L-arginines (p < .01), L-arginine/ADMA (p < .0001), and L-arginine/SDMA (p < .01, respectively <.001) compared to ECS. However, ILVB had higher ADMA (p < .0001) and lower L-arginine (p < .01), L-arginine/ADMA (p < .0001), and L-arginine/SDMA (p < .01) compared to SLVB. Results are adjusted for gestational length at birth and cervical dilatation at sampling.CONCLUSION: Our novel findings of higher levels of dimethylarginines in term vaginal births compared to ECS give insights into the biochemical mechanisms of labor. These findings might also serve as a basis for further studies of arginines in complicated pregnancies and labor.
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| 8. |
- Andersson, Mathias, et al.
(författare)
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Management Measures to Reduce Continuous Underwater Noise from Shipping
- 2023
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Rapport (refereegranskat)abstract
- Underwater radiated noise (URN) from commercial ships is a significant source of elevated noise levels in the oceans and can have a negative impact on marine wildlife. Noise from commercial shipping places additional stress on the oceans, but is one of the least studied environmental pollutants, and there is an urgent need to reduce the aggregate stress levels. Until recently, reduction of underwater noise has not been prioritised by ship designers, shipowners, or crews. Even within the field of marine management, noise has received limited interest. However, the International Maritime organization (IMO) has adopted global guidelines on URN reduction, which are currently being updated. Within the EU, the Marine Strategy Framework Directive (MSFD 2008/56/EC) Descriptor 11 criteria 11.2, now provides a framework for marine administrators to manage noise by establishing threshold values. Marine management focuses on the total noise load on the marine environment. Management entails several considerations before recommendations can be made. As a first step, interdisciplinary teams need to assess the aggregated noise levels and determine acceptable thresholds based on the local ecosystem, then assess which existing mandates and management tools can be used, and finally assess how effective these mandates have been in improving the environment. These activities must also be managed in a way that is acceptable to various relevant stakeholders, who would need to follow the decisions. The URN from a ship can be affected by the vessel’s design, either during its construction or during upgrades, and balances a trade-off against fuel efficiency. However, the URN can also depend on how the ship is operated. Regulating ship speed is one potential management tool, and its effectiveness needs to be assessed. Other management measures include how shipping lanes are drawn, areas to avoid, financial support, information, etc. This report focuses on possible policy measures that the Swedish authorities could adopt to lower URN by regulating the speed of ships. The report presents an interdisciplinary analysis, using a case study of an area in the southern Kattegat that covered several maritime zones, different national jurisdictions, intensive traffic, and high natural values. An important part of the work was to assess whether existing source models for ship noise could be used for the type of ships that are common in waters around Sweden. In this study, the JOMOPANS-ECHO (J-E) model was used.The J-E model was validated by comparing measurement data from a hydrophone station at Vinga on the Swedish coast that collected data from ships (254 passages) that used the port of Gothenburg. The analysis showed some deviation between the J-E model and measurement data, which could be due to differences in the length and speed of ships in waters around Sweden compared to the ships used in the development of the J-E model. However, this was likely to have negligible impact on the outcome of the case study.Analyses of ship traffic in 2021 showed that 4,511 unique vessels visited the study area at least once. Most ships followed the main routes, but no part of the study area was completely free from ship traffic. About 68% of the ships visited the study area for 1-4 days, while about 32% visited the area more regularly. The most common ship types were General Cargo Ships, Dry Bulk Ships, and Tankers. The ships that on average travelled at highest speeds were RoPax Ships, RoRo Ships, Vehicle Carriers, and Container Ships. The ships were registered in 64 countries. About two percent of the ships were registered in Sweden and about four percent in Denmark.Legal analysis showed that Sweden has the right and the responsibility to take measures to reduce underwater noise from ships to the extent that the noise can be deemed to pollute the marine environment. However, this mainly applies to Sweden’s territorial seas, which cover roughly half the area being studied for this report. In the portion that constitutes Danish territorial sea, Denmark has comparable opportunities for managing URN. In areas that are Swedish or Danish exclusive economic zones (EEZs), the ability to introduce mandatory speed limits is significantly limited. There, the most realistic option would be to request the IMO to establish speed limits, or alternatively to issue a recommendation to navigate at lower speeds, although such guidance could not be enforced on ships that do not voluntarily reduce their speed.It was estimated that lowering the ships' speeds to a hypothetical limit of 11 kn would reduce the average URN levels by 4.4 ± 2 dB, as registered by local receivers in the study area. This speed limit would affect approximately 44% of the ships in the area. A maximum speed of 13 kn would instead reduce the level by 1.9 ± 0.5 dB and would affect 11% of the ships on average. The reduction in noise levels may temporarily be much higher in the immediate vicinity of individual fast ships, and there might be a high degree of variation between different ships.The study and report make it clear that it is a complex task to assess the feasibility and benefit of introducing a specific marine management tool, in this case an enforceable local speed limit. But it is also clear that there are reliable methods to make the preliminary assessments, and that it requires interdisciplinary analyses and competence.
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| 9. |
- Aramrattana, Maytheewat, 1988-, et al.
(författare)
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Remote Driving Operation (REDO) project : final report
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents experimental setups and findings from the REDO project, which had been conducted between December 2019 and February 2023. Five main topics are covered in this report: 1) Effects of latency and field-of-view on driving performance; 2) Remote driving feedback and control; 3) Connectivity and mobile network support for remote driving; 4) Video transmission for remote driving; and 5) Laws and regulations concerning remote driving. Contents of this report dives into technical details and findings within each topic. Nevertheless, this report does not intend to repeat all detail and results published in scientific publications, and thus this report should be seen as complementary material to the published results.
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| 10. |
- Arumughan, Vishnu, 1994, et al.
(författare)
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Anion-Specific Adsorption of Carboxymethyl Cellulose on Cellulose
- 2023
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 39:42, s. 15014-15021
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Tidskriftsartikel (refereegranskat)abstract
- Integration of fiber modification step with a modern pulp mill is a resource efficient way to produce functional fibers. Motivated by the need to integrate polymer adsorption with the current pulping system, anion-specific effects in carboxymethylcellulose (CMC) adsorption have been studied. The QCM-D adsorption experiments revealed that CMC adsorption to the cellulose model surface is prone to anion-specific effects. A correlation was observed between the adsorbed CMC and the degree of hydration of the co-ions present in the magnesium salts. The presence of a chaotropic co-ion such as nitrate increased the adsorption of CMC on cellulose compared to the presence of the kosmotropic sulfate co-ion. However, anion-specificity was not significant in the case of salts containing zinc cations. The hydration of anions determines the distribution of the ions at the interface. Chaotropic ions, such as nitrates, are likely to be distributed near the chaotropic cellulose surface, causing changes in the ordering of water molecules and resulting in greater entropy gain once released from the surface, thus increasing CMC adsorption.
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