| 1. |
- Chartkunchand, K. C., et al.
(författare)
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Lifetimes of bound excited states of Pt-
- 2017
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Ingår i: Journal of Physics: Conference Series, Vol. 875, no. 022051. - : IOP Publishing. - 1742-6588.
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Konferensbidrag (refereegranskat)abstract
- Measurements of the radiative lifetimes of the two excited states of the platinum anion Pt- are presented. Pt- ions stored in the cryogenic ion storage ring DESIREE were photodetached at different photon wavelengths and the resulting yield of neutral Pt measured as a function of time was recorded. Analysis of the neutral decay curves show a 2.54 +/- 0.10 s lifetime for the higher-lying 5d(10)6(s) S-2(1/2) excited state and a lifetime in the range of 50-200 ms for the lower- lying 5d(9)6(s)(2) D-2(3/2) excited state. This is the first study to report the lifetime of a bound anion excited state with an electron configuration different from that of the anion ground state.
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| 2. |
- Mernelius, S., et al.
(författare)
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Staphylococcus aureus colonization related to severity of hand eczema
- 2016
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Ingår i: European Journal of Clinical Microbiology and Infectious Diseases. - : Springer. - 0934-9723 .- 1435-4373. ; 35:8, s. 1355-1361
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge on Staphylococcus aureus colonization rates and epidemiology in hand eczema is limited. The aim of this study was to clarify some of these issues. Samples were collected by the "glove juice" method from the hands of 59 patients with chronic hand eczema and 24 healthy individuals. Swab samples were taken from anterior nares and throat from 43 of the 59 patients and all healthy individuals. S. aureus were spa typed and analysed by DNA-microarray-based genotyping. The extent of the eczema was evaluated by the hand eczema extent score (HEES). The colonization rate was higher on the hands of hand eczema patients (69 %) compared to healthy individuals (21 %, p amp;lt; 0.001). This was also seen for bacterial density (p = 0.002). Patients with severe hand eczema (HEES a parts per thousand yen 13) had a significantly higher S. aureus density on their hands compared to those with milder eczema (HEES = 1 to 12, p = 0.004). There was no difference between patients and healthy individuals regarding colonization rates in anterior nares or throat. spa typing and DNA-microarray-based genotyping indicated certain types more prone to colonize eczematous skin. Simultaneous colonization, in one individual, with S. aureus of different types, was identified in 60-85 % of the study subjects. The colonization rate and density indicate a need for effective treatment of eczema and may have an impact on infection control in healthcare.
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| 3. |
- Audet, J., et al.
(författare)
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Forest streams are important sources for nitrous oxide emissions
- 2020
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Ingår i: Global Change Biology. - : Wiley. - 1354-1013 .- 1365-2486. ; 26:2, s. 629-641
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Tidskriftsartikel (refereegranskat)abstract
- Streams and river networks are increasingly recognized as significant sources for the greenhouse gas nitrous oxide (N2O). N2O is a transformation product of nitrogenous compounds in soil, sediment and water. Agricultural areas are considered a particular hotspot for emissions because of the large input of nitrogen (N) fertilizers applied on arable land. However, there is little information on N2O emissions from forest streams although they constitute a major part of the total stream network globally. Here, we compiled N2O concentration data from low-order streams (~1,000 observations from 172 stream sites) covering a large geographical gradient in Sweden from the temperate to the boreal zone and representing catchments with various degrees of agriculture and forest coverage. Our results showed that agricultural and forest streams had comparable N2O concentrations of 1.6±2.1 and 1.3±1.8µgN/L, respectively (mean±SD) despite higher total N (TN) concentrations in agricultural streams (1,520±1,640 vs. 780±600µgN/L). Although clear patterns linking N2O concentrations and environmental variables were difficult to discern, the percent saturation of N2O in the streams was positively correlated with stream concentration of TN and negatively correlated with pH. We speculate that the apparent contradiction between lower TN concentration but similar N2O concentrations in forest streams than in agricultural streams is due to the low pH (<6) in forest soils and streams which affects denitrification and yields higher N2O emissions. An estimate of the N2O emission from low-order streams at the national scale revealed that ~1.8×109g N2O-N are emitted annually in Sweden, with forest streams contributing about 80% of the total stream emission. Hence, our results provide evidence that forest streams can act as substantial N2O sources in the landscape with 800×109gCO2-eq emitted annually in Sweden, equivalent to 25% of the total N2O emissions from the Swedish agricultural sector. © 2019 The Authors. Global Change Biology published by John Wiley & Sons Ltd
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| 6. |
- Bäckström, Torbjörn, et al.
(författare)
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Paradoxical effects of GABA-A modulators may explain sex steroid induced negative mood symptoms in some persons
- 2011
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Ingår i: Neuroscience. - Oxford : Elsevier BV. - 0306-4522 .- 1873-7544. ; 191:Special issue, s. 46-54
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Forskningsöversikt (refereegranskat)abstract
- Some women have negative mood symptoms, caused by progestagens in hormonal contraceptives or sequential hormone therapy or by progesterone in the luteal phase of the menstrual cycle, which may be attributed to metabolites acting on the GABA-A receptor. The GABA system is the major inhibitory system in the adult CNS and most positive modulators of the GABA-A receptor (benzodiazepines, barbiturates, alcohol, GABA steroids), induce inhibitory (e.g. anesthetic, sedative, anticonvulsant, anxiolytic) effects. However, some individuals have adverse effects (seizures, increased pain, anxiety, irritability, aggression) upon exposure. Positive GABA-A receptor modulators induce strong paradoxical effects including negative mood in 3%-8% of those exposed, while up to 25% have moderate symptoms. The effect is biphasic: low concentrations induce an adverse anxiogenic effect while higher concentrations decrease this effect and show inhibitory, calming properties. The prevalence of premenstrual dysphoric disorder (PMDD) is also 3%-8% among women in fertile ages, and up to 25% have more moderate symptoms of premenstrual syndrome (PMS). Patients with PMDD have severe luteal phase-related symptoms and show changes in GABA-A receptor sensitivity and GABA concentrations. Findings suggest that negative mood symptoms in women with PMDD are caused by the paradoxical effect of allopregnanolone mediated via the GABA-A receptor, which may be explained by one or more of three hypotheses regarding the paradoxical effect of GABA steroids on behavior: (1) under certain conditions, such as puberty, the relative fraction of certain GABA-A receptor subtypes may be altered, and at those subtypes the GABA steroids may act as negative modulators in contrast to their usual role as positive modulators; (2) in certain brain areas of vulnerable women the transmembrane C1(-) gradient may be altered by factors such as estrogens that favor excitability; (3) inhibition of inhibitory neurons may promote disinhibition, and hence excitability. This article is part of a Special Issue entitled: Neuroactive Steroids: Focus on Human Brain. (C) 2011 Published by Elsevier Ltd on behalf of IBRO.
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| 7. |
- Dahl, Martin, 1984-, et al.
(författare)
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First assessment of seagrass carbon accumulation rates in Sweden: A field study from a fjord system at the Skagerrak coast
- 2023
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Ingår i: PLoS Climate. - : Public Library of Science (PLoS). - 2767-3200. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Seagrass meadows are globally important blue carbon sinks. In northern cold-temperate regions, eelgrass (Zostera marina) is the dominant seagrass species, and although their sedimentary carbon stocks have been quantified across regions, information regarding the CO2 withdrawal capacity as carbon sinks remains scarce. Here we assessed the carbon (Corg) accumulation rates (CARs) and stocks as well as the organic matter sources in five seagrass meadows in the Gullmar Fjord area on the Swedish Skagerrak coast. We found that the mean (±SD) CAR was 14 ± 3 g Corg m-2 yr-1 over the last ~120–140 years (corresponding to a yearly uptake of 52.4 ± 12.6 g CO2 m-2). The carbon sink capacity is in line with other Z. marina areas but relatively low compared to other seagrass species and regions globally. About half of the sedimentary carbon accumulation (7.1 ± 3.3 g Corg m-2 yr-1) originated from macroalgae biomass, which highlights the importance of non-seagrass derived material for the carbon sink function of seagrass meadows in the area. The Corg stocks were similar among sites when comparing at a standardized depth of 50 cm (4.6–5.9 kg Corg m-2), but showed large variation when assessed for the total extent of the cores (ranging from 0.7 to 20.6 kg Corg m-2 for sediment depths of 11 to at least 149 cm). The low sediment accretion rates (1.18–1.86 mm yr-1) and the relatively thick sediment deposits (with a maximum of >150 cm of sediment depth) suggests that the carbon stocks have likely been accumulated for an extended period of time, and that the documented loss of seagrass meadows in the Swedish Skagerrak region and associated erosion of the sediment could potentially have offset centuries of carbon sequestration.
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| 8. |
- Hammarskjöld, Fredrik, et al.
(författare)
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Possible transmission of Candida albicans on an intensive care unit : intensive care unit
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Nosocomial transmission of Candida spp. has not fully been explored and previous studies have shown conflicting results.Aim: To evaluate the possible nosocomial transmission of Candida spp. on an intensive care unit (ICU).Methods: We conducted a prospective study over 19 month, including all patients on our ICU with growth of Candida spp. from surveillance and directed cultures. Molecular typing, with rep-PCR (DiversiLab) was used to define genotype relationships between the C. albicans and C. glabrata isolates. Candida isolates obtained from blood cultures taken from patients in our county outside the ICU, were used as a reference. Temporal cluster analysis was performed to evaluate genotype distribution over time.Findings: Seventy-seven patients with 78 ICU stays, representing twelve per cent of all ICU stays, were found to harbour 180 isolates of Candida spp. Molecular typing revealed 27 C. albicans genotypes and ten of C. glabrata. Possible clustering, indicated by overlapping stays of patients with indistinguishable candida genotypes was observed on seven occasions with C. albicans and on two occasions with C. glabrata. Two C. albicans genotypes were found significantly more often in the ICU group compared to the reference group. Moreover, C. albicans genotypes isolated from more than one patient were significantly more often found in the ICU group. Temporal cluster analysis revealed a significantly increased number of pairs with indistinguishable genotypes at a 21-dayinterval, indicating clustering.Conclusion: This study indicates transmission of C. albicans between ICU patients based on genotyping and temporal cluster analysis.
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| 9. |
- Kaminska, M, et al.
(författare)
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Storing keV negative ions for hours: Lifetime measurements in new time domains
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Konferensbidrag (refereegranskat)abstract
- We have used one of the cryogenic ion storage rings of DESIREE to measure the lifetime of the 2P o 1/2 level in the sulfur anion to be 503 ± 43 seconds. This is orders of magnitude longer than any previously measured lifetime in a negatively charged ion.
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| 10. |
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