| 1. |
- Dahl, Martin, et al.
(författare)
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Effects of shading and simulated grazing on carbon sequestration in a tropical seagrass meadow
- 2016
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Ingår i: Journal of Ecology. - : Wiley. - 0022-0477 .- 1365-2745. ; 104:3, s. 654-664
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Tidskriftsartikel (refereegranskat)abstract
- 1. There is an ongoing world-wide decline of seagrass ecosystems, one of the world's most efficient carbon sink habitats. In spite of this, there is a clear lack of studies experimentally testing the effects of anthropogenic disturbances on carbon sequestration of seagrass systems. 2. We assessed the effects of two disturbances of global concern on the carbon sink function in a five-month in situ experiment within a tropical seagrass (Thalassia hemprichii) meadow by testing the impacts of shading and simulated grazing at two levels of intensity using shading cloths and clipping of shoot tissue. We measured the effects of these disturbances on the carbon sequestration process by assessing the net community production (NCP), carbon and nitrogen content in tissue biomass, and organic matter and THAA (total hydrolysable amino acids) in the sediment down to 40 cm depth. 3. Treatments of high-intensity shading and high-intensity clipping were similarly impacted and showed a significantly lower NCP and carbon content in the below-ground biomass compared to the seagrass control. No significant effects were seen in organic carbon, total nitrogen, C:N ratio and THAA in the sediment for the seagrass treatments. However, both clipping treatments showed different depth profiles of carbon and THAA compared to the seagrass control, with lower organic carbon and THAA content in the surface sediment. This can be explained by the clipping of shoot tissue causing a less efficient trapping of allochthonous carbon and reduced input of shredded seagrass leaves to the detritus sediment layer. In the clipping plots, erosion of the surface sediment occurred, which was also most likely caused by the removal of above-ground plant biomass. 4. Synthesis. Our findings show that during the course of this experiment, there were no impacts on the sedimentary carbon while the high-intensity disturbances caused a clear depletion of carbon biomass and reduced the seagrass meadow's capacity to sequester carbon. From a long-term perspective, the observed effect on the carbon biomass pool in the high-intensity treatments and the sediment erosion in the clipping plots may lead to loss in sedimentary carbon.
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| 2. |
- Estenberg, Martin, 1970-
(författare)
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"Ett snäpp högre" : En studie av historielärares hanterande av tankeredskap.
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Abstract The aim with this study is to examine how practicing history teachers in upper secondary school deal with historical thinking concepts. The three main questions are: which concepts do teachers use in their courses and when do they use them? How can teachers’ use of different historical thinking concepts be described in terms of reconstruction and construction? What factors influence teachers when they work with historical thinking concepts? To answer these questions, the material, for example tests, lesson plans and notes of seven teachers has been analyzed. These analysis were followed by interviews with the teachers. The empirical data have been handled in two steps. The first step is a survey of what historical thinking concepts teachers use and when they use them. The survey was done as a detailed reading of the teachers’ material. In this survey two historical thinking concepts, evidence and cause and consequence, have been selected for further analysis, which is the second step. The results show that when teachers deal with the historical thinking concept of evidence they show their students models and ways to handle evidence. This is not the case when teachers handle the historical thinking concept of cause and consequence. Models are shown here as well but not to the same extent. The result also shows that the teachers’ handling of evidence in a greater extent leads to construction compared with their handling of cause and consequence. The explanations provided in the study also point to the different character between the two concepts and what form of test the teachers’ use and what words are used to communicate for example cause and consequence. Furthermore, the explanations also indicate that the teachers’ view of what historical knowledge contains of, together with what kind of students and what other subject they teach play some part in their dealing with historical thinking concepts.
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| 3. |
- Gullström, Martin, et al.
(författare)
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Blue Carbon Storage in Tropical Seagrass Meadows Relates to Carbonate Stock Dynamics, Plant–Sediment Processes, and Landscape Context : Insights from the Western Indian Ocean
- 2018
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Ingår i: Ecosystems (New York. Print). - : Springer Science and Business Media LLC. - 1432-9840 .- 1435-0629. ; 21:3, s. 551-566
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Tidskriftsartikel (refereegranskat)abstract
- Globally, seagrass ecosystems are considered major blue carbon sinks and thus indirect contributors to climate change mitigation. Quantitative estimates and multi-scale appraisals of sources that underlie long-term storage of sedimentary carbon are vital for understanding coastal carbon dynamics. Across a tropical–subtropical coastal continuum in the Western Indian Ocean, we estimated organic (Corg) and inorganic (Ccarb) carbon stocks in seagrass sediment. Quantified levels and variability of the two carbon stocks were evaluated with regard to the relative importance of environmental attributes in terms of plant–sediment properties and landscape configuration. The explored seagrass habitats encompassed low to moderate levels of sedimentary Corg (ranging from 0.20 to 1.44% on average depending on species- and site-specific variability) but higher than unvegetated areas (ranging from 0.09 to 0.33% depending on site-specific variability), suggesting that some of the seagrass areas (at tropical Zanzibar in particular) are potentially important as carbon sinks. The amount of sedimentary inorganic carbon as carbonate (Ccarb) clearly corresponded to Corg levels, and as carbonates may represent a carbon source, this could diminish the strength of seagrass sediments as carbon sinks in the region. Partial least squares modelling indicated that variations in sedimentary Corg and Ccarb stocks in seagrass habitats were primarily predicted by sediment density (indicating a negative relationship with the content of carbon stocks) and landscape configuration (indicating a positive effect of seagrass meadow area, relative to the area of other major coastal habitats, on carbon stocks), while seagrass structural complexity also contributed, though to a lesser extent, to model performance. The findings suggest that accurate carbon sink assessments require an understanding of plant–sediment processes as well as better knowledge of how sedimentary carbon dynamics are driven by cross-habitat links and sink–source relationships in a scale-dependent landscape context, which should be a priority for carbon sink conservation.
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| 4. |
- Ansell - Schultz, Anna, et al.
(författare)
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Reduced retromer function results in the accumulation of amyloid-beta oligomers
- 2018
-
Ingår i: Molecular and Cellular Neuroscience. - : Academic Press. - 1044-7431 .- 1095-9327. ; 93, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimers disease (AD) is a neurodegenerative disorder characterized by a progressive loss of multiple cognitive functions. Accumulation of amyloid beta oligomers (oA beta) play a major role in the neurotoxicity associated with the disease process. One of the early affected brain regions is the hippocampus, wherein a reduction of the vacuolar protein sorting-associated protein 35 (VPS35), the core protein comprising the retromer complex involved in cellular cargo sorting, has been identified. To investigate the role of the retromer function on the accumulation and clearance of oA beta, we reduced retromer function by selectively inhibiting VPS35 gene expression using siRNA in differentiated neuronal SH-SY5Y cells. As cell-to-cell transfer of oA beta to new brain regions is believed to be important for disease progression we investigated the effect of VPS35 reduction both in cells with direct uptake of oA beta and in cells receiving oA beta from donor cells. We demonstrate that reduced retromer function increases oA beta accumulation in both cell systems, both the number of cells containing intracellular oA beta and the amount within them. This effect was shown at different time points and regardless if the AD originated from the extracellular milieu or via a direct neuronal cell-to-cell transfer. Interestingly, not only did reduced VPS35 cause oA beta accumulation, but oA beta treatment alone also lead to a reduction of VPS35 protein content. The accumulated oA beta seems to co-localize with VPS35 and early endosome markers. Together, these findings provide evidence that reduced retromer function decreases the ability for neurons to transport and clear neurotoxic oA beta received through different routes resulting in the accumulation of oA beta. Thus, enhancing retromer function may be a potential therapeutic strategy to slow down the pathophysiology associated with the progression of AD.
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| 5. |
- Asplund Samuelsson, Johannes, et al.
(författare)
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Diversity and expression of bacterial metacaspases in an aquatic ecosystem
- 2016
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 7, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Metacaspases are distant homologs of metazoan caspase proteases, implicated in stress response, and programmed cell death (PCD) in bacteria and phytoplankton. While the few previous studies on metacaspases have relied on cultured organisms and sequenced genomes, no studies have focused on metacaspases in a natural setting. We here present data from the first microbial community-wide metacaspase survey; performed by querying metagenomic and metatranscriptomic datasets from the brackish Baltic Sea, a water body characterized by pronounced environmental gradients and periods of massive cyanobacterial blooms. Metacaspase genes were restricted to ~4% of the bacteria, taxonomically affiliated mainly to Bacteroidetes, Alpha- and Betaproteobacteria and Cyanobacteria. The gene abundance was significantly higher in larger or particle-associated bacteria (<0.8 μm), and filamentous Cyanobacteria dominated metacaspase gene expression throughout the bloom season. Distinct seasonal expression patterns were detected for the three metacaspase genes in Nodularia spumigena, one of the main bloom-formers. Clustering of normalized gene expression in combination with analyses of genomic and assembly data suggest functional diversification of these genes, and possible roles of the metacaspase genes related to stress responses, i.e., sulfur metabolism in connection to oxidative stress, and nutrient stress induced cellular differentiation. Co-expression of genes encoding metacaspases and nodularin toxin synthesis enzymes was also observed in Nodularia spumigena. The study shows that metacaspases represent an adaptation of potentially high importance for several key organisms in the Baltic Sea, most prominently Cyanobacteria, and open up for further exploration of their physiological roles in microbes and assessment of their ecological impact in aquatic habitats.
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| 6. |
- Bay-Richter, Cecilie, et al.
(författare)
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A role for inflammatory metabolites as modulators of the glutamate N-methyl-D-aspartate receptor in depression and suicidality
- 2015
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Ingår i: Brain, behavior, and immunity. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0889-1591 .- 1090-2139. ; 43, s. 110-117
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with depression and suicidality suffer from low-grade neuroinflammation. Proinflammatory cytokines activate indoleamine 2,3-dioxygenase, an initial enzyme of the kynurenine pathway. This pathway produces neuroactive metabolites, including quinolinic- and kynurenic acid, binding to the glutamate N-methyl-D-aspartate-receptor, which is hypothesized to be part of the neural mechanisms underlying symptoms of depression. We therefore hypothesized that symptoms of depression and suicidality would fluctuate over time in patients prone to suicidal behavior, depending on the degree of inflammation and kynurenine metabolite levels in the cerebrospinal fluid (CSF). Methods: We measured cytokines and kynurenine metabolites in CSF, collected from suicide attempters at repeated occasions over 2 years (total patient samples n = 143, individuals n = 30) and healthy controls (n = 36). The association between the markers and psychiatric symptoms was assessed using the Montgomery Asberg Depression Rating Scale and the Suicide Assessment Scale. Results: Quinolinic acid was increased and kynurenic acid decreased over time in suicidal patients versus healthy controls. Furthermore, we found a significant association between low kynurenic acid and severe depressive symptoms, as well as between high interleukin-6 levels and more severe suicidal symptoms. Conclusions: We demonstrate a long-term dysregulation of the kynurenine pathway in the central nervous system of suicide attempters. An increased load of inflammatory cytokines was coupled to more severe symptoms. We therefore suggest that patients with a dysregulated kynurenine pathway are vulnerable to develop depressive symptoms upon inflammatory conditions, as a result the excess production of the NMDA-receptor agonist quinolinic acid. This study provides a neurobiological framework supporting the use of NMDA-receptor antagonists in the treatment of suicidality and depression. (C) 2014 Elsevier Inc. All rights reserved.
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| 7. |
- Berg, Carlo, et al.
(författare)
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Dissection of Microbial Community Functions during a Cyanobacterial Bloom in the Baltic Sea via Metatranscriptomics
- 2018
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745.
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Tidskriftsartikel (refereegranskat)abstract
- Marine and brackish surface waters are highly dynamic habitats that undergo repeated seasonal variations in microbial community composition and function throughout time. While succession of the various microbial groups has been well investigated, little is known about the underlying gene-expression of the microbial community. We investigated microbial interactions via metatranscriptomics over a spring to fall seasonal cycle in the brackish Baltic Sea surface waters, a temperate brackish water ecosystem periodically promoting massive cyanobacterial blooms, which have implications for primary production, nutrient cycling, and expansion of hypoxic zones. Network analysis of the gene expression of all microbes from 0.22 to 200 mu m in size and of the major taxonomic groups dissected the seasonal cycle into four components that comprised genes peaking during different periods of the bloom. Photoautotrophic nitrogen-fixing Cyanobacteria displayed the highest connectivity among the microbes, in contrast to chemoautotrophic ammonia-oxidizing Thaumarchaeota, while heterotrophs dominated connectivity among pre- and post-bloom peaking genes. The network was also composed of distinct functional connectivities, with an early season balance between carbon metabolism and ATP synthesis shifting to a dominance of ATP synthesis during the bloom, while carbon degradation, specifically through the glyoxylate shunt, characterized the post-bloom period, driven by Alphaproteobacteria as well as by Gammaproteobacteria of the SAR86 and SAR92 clusters. Our study stresses the exceptionally strong biotic driving force executed by cyanobacterial blooms on associated microbial communities in the Baltic Sea and highlights the impact cyanobacterial blooms have on functional microbial community composition.
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| 8. |
- Brandberg, Martin, 1972, et al.
(författare)
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A comparative study on simple and interference reaction times in women and men.
- 2018
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Ingår i: Conference program, The 13th Nordic Meeting in Neuropsychology, Stockholm, 2018.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: studies on reaction time (RT) indicate faster reactions for men than women. However, when comparing samples across decades, this difference seems to decrease. The aim of this study was to explore reaction times in a large contemporary sample of adult males and females (age range = 15-82). Methods: Simple reaction time and interference reaction time (a go/no go reaction task) were measured with the Vienna Reaction Apparatus (Wiener Reaktionstest, Schuhfried), RT, version S1 and S2 for simple reaction time and version S3 and S4 for interference reaction time. Results: men responded faster on the interference reaction task, S3 (M=441,57, SD=80,86) than women (M=461,53, SD=91,53). This difference was significant, t(3,7) = p<0,001 and represent a small sized effect, d = .21. There were no significant differences regarding simple reaction time (S1 and S2) or on the other interference task (S4). In regards to intraindividual variability there was a significant difference, t(3.1), p =.002, d =.21, with less variability in males (M =65.99) as compared to females (M=70,45) on S3. Conclusions: when comparing groups, men performed slightly faster on one of the interference tasks. However, there were no significant differences on the other measures. This result is consistent with previous studies indicating a decrease in differences on reaction times, comparing men and women.
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| 9. |
- Brundin, L., et al.
(författare)
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An enzyme in the kynurenine pathway that governs vulnerability to suicidal behavior by regulating excitotoxicity and neuroinflammation
- 2016
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Ingår i: Translational Psychiatry. - : Springer Science and Business Media LLC. - 2158-3188. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Emerging evidence suggests that inflammation has a key role in depression and suicidal behavior. The kynurenine pathway is involved in neuroinflammation and regulates glutamate neurotransmission. In the cerebrospinal fluid (CSF) of suicidal patients, levels of inflammatory cytokines and the kynurenine metabolite quinolinic acid (QUIN), an N-methyl-D-aspartate receptor agonist, are increased. The enzyme amino-beta-carboxymuconate-semialdehyde-decarboxylase (ACMSD) limits QUIN formation by competitive production of the neuroprotective metabolite picolinic acid (PIC). Therefore, decreased ACMSD activity can lead to excess QUIN. We tested the hypothesis that deficient ACMSD activity underlies suicidal behavior. We measured PIC and QUIN in CSF and plasma samples from 137 patients exhibiting suicidal behavior and 71 healthy controls. We used DSM-IV and the Montgomery-Asberg Depression Rating Scale and Suicide Assessment Scale to assess behavioral changes. Finally, we genotyped ACMSD tag single nucleotide polymorphisms (SNPs) in 77 of the patients and 150 population-based controls. Suicide attempters had reduced PIC and a decreased PIC/QUIN ratio in both CSF (P<0.001) and blood (P=0.001 and P<0.01, respectively). The reductions of PIC in CSF were sustained over 2 years after the suicide attempt based on repeated measures. The minor C allele of the ACMSD SNP rs2121337 was more prevalent in suicide attempters and associated with increased CSF QUIN. Taken together, our data suggest that increased QUIN levels may result from reduced activity of ACMSD in suicidal subjects. We conclude that measures of kynurenine metabolites can be explored as biomarkers of suicide risk, and that ACMSD is a potential therapeutic target in suicidal behavior.
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| 10. |
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| 11. |
- Enmark, Martin, 1984-, et al.
(författare)
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A closer study of peak distortions in supercritical fluid chromatography as generated by the injection
- 2015
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1400, s. 131-139
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Tidskriftsartikel (refereegranskat)abstract
- Abstract In SFC the sample cannot be dissolved in the mobile phase, so it is often dissolved in pure modifier, or another liquid, sometimes resulting in serious distortions of the eluted peak profiles already at moderately high injection volumes. It is suspected the reasons for these effects are solvent strength mismatch and/or viscosity mismatch. This study presents a systematic and fundamental investigation of the origin of these peak deformations due to the injection solvent effects in SFC, using both systematic experiments and numerical modeling. The first set of experiments proved that the injection volume and the elution strength of the sample solution had a major impact of the shapes of the eluted peaks. Secondly, the sample band elution profile was numerically modeled on a theoretical basis assuming both un-retained and retained co-solvent injection plugs, respectively. These calculations quantitatively confirmed our first set of experiments but also pointed out that there is also an additional significant effect. Third, viscous fingering experiments were performed using viscosity contrast conditions imitating those encountered in SFC. These experiments clearly proved that viscous fingering effects play a significant role. A new method for determination of adsorption isotherms of solvents was also developed, called the “Retention Time Peak Method” (RTPM). The RTPM was used for fast estimation of the adsorption isotherms of the modifier and required using only two experiments.
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| 12. |
- Enmark, Martin, et al.
(författare)
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Evaluation of scale-up from analytical to preparative supercritical fluid chromatography
- 2015
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1425, s. 280-286
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Tidskriftsartikel (refereegranskat)abstract
- An approach for reliable transfer from analytical to preparative scale supercritical fluid chromatography was evaluated. Here, we accounted for the conditions inside the columns as well as to the fact that most analytical instruments are volume-controlled while most preparative scale units are mass-controlled. The latter is a particular problem when performing pilot scale experiments and optimizations prior to scaling up to production scale. This was solved by measuring the mass flow, the pressure and the temperature on the analytical unit using external sensors. Thereafter, it was revealed with a design of experiments approach that the methanol fraction and the pressure are the two most important parameters to control for preserved retention throughout the scale-up; for preserved selectivity the temperature was most important in this particular system. Using this approach, the resulting chromatograms from the preparative unit agreed well with those from the analytical unit while keeping the same column length and particles size. A brief investigation on how the solute elution volume varies with the volumetric flow rate revealed a complex dependency on pressure, density and apparent methanol content. Since the methanol content is a parameter of great importance to control during the scale up, we must be careful when changing operational and column design conditions which generates deviations in pressure, density and methanol content between different columns. (C) 2015 Elsevier B.V. All rights reserved.
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| 13. |
- Enmark, Martin, 1984-, et al.
(författare)
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Investigation of factors influencing the separation of diastereomers of phosphorothioated oligonucleotides
- 2019
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer. - 1618-2642 .- 1618-2650. ; 411:15, s. 3383-3394
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a systematic investigation of factors influencing the chromatographic separation of diastereomers of phosphorothioated pentameric oligonucleotides as model solutes. Separation was carried out under ion-pairing conditions using an XBridge C18 column. For oligonucleotides with a single sulfur substitution, the diastereomer selectivity was found to increase with decreasing carbon chain length of the tertiary alkylamine used as an ion-pair reagent. Using an ion-pair reagent with high selectivity for diastereomers, triethylammonium, it was found the selectivity increased with decreased ion-pair concentration and shallower gradient slope. Selectivity was also demonstrated to be dependent on the position of the modified linkage. Substitutions at the center of the pentamer resulted in higher diastereomer selectivity compared to substitutions at either end. For mono-substituted oligonucleotides, the retention order and stereo configuration were consistently found to be correlated, with Rp followed by Sp, regardless of which linkage was modified. The type of nucleobase greatly affects the observed selectivity. A pentamer of cytosine has about twice the diastereomer selectivity of that of thymine. When investigating the retention of various oligonucleotides eluted using tributylammonium as the ion-pairing reagent, no diastereomer selectivity could be observed. However, retention was found to be dependent on both the degree and position of sulfur substitution as well as on the nucleobase. When analyzing fractions collected in the front and tail of overloaded injections, a significant difference was found in the ratio between Rp and Sp diastereomers, indicating that the peak broadening observed when using tributylammonium could be explained by partial diastereomer separation.
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| 14. |
- Enmark, Martin, 1984-, et al.
(författare)
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Investigation of robustness for supercritical fluid chromatography separation of peptides : Isocratic vs gradient mode
- 2018
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1568, s. 177-187
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Tidskriftsartikel (refereegranskat)abstract
- We investigated and compared the robustness of supercritical fluid chromatography (SFC) separations of the peptide gramicidin, using either isocratic or gradient elution. This was done using design of experiments in a design space of co-solvent fraction, water mass fraction in co-solvent, pressure, and temperature. The density of the eluent (CO2-MeOH-H2O) was experimentally determined using a Coriolis mass flow meter to calculate the volumetric flow rate required by the design. For both retention models, the most important factor was the total co-solvent fraction and water mass fraction in co-solvent. Comparing the elution modes, we found that gradient elution was more than three times more robust than isocratic elution. We also observed a relationship between the sensitivity to changes and the gradient steepness and used this to draw general conclusions beyond the studied experimental system. To test the robustness in a practical context, both the isocratic and gradient separations were transferred to another laboratory. The gradient elution was highly reproducible between laboratories, whereas the isocratic system was not. Using measurements of the actual operational conditions (not the set system conditions), the isocratic deviation was quantitatively explained using the retention model. The findings indicate the benefits of using gradient elution in SFC as well as the importance of measuring the actual operational conditions to be able to explain observed differences between laboratories when conducting method transfer.
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| 15. |
- Forss, Erik, et al.
(författare)
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Chemometric evaluation of the combined effect of temperature, pressure, and co-solvent fractions on the chiral separation of basic pharmaceuticals using actual vs set operational conditions
- 2017
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Ingår i: Journal of Chromatography A. - : Elsevier. - 0021-9673 .- 1873-3778. ; 1499, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- The need to determine the actual operational conditions, instead of merely using the set operational conditions, was investigated for in packed supercritical fluid chromatography (SFC) by design of experiments (DoE) using a most important type of compounds, pharmaceutical basics, as models. The actual values of temperature, pressure, and methanol levels were recorded and calculated from external sensors, while the responses in the DoE were the retention factors and selectivity. A Kromasil CelluCoat columh was used as the stationary phase, carbon dioxide containing varying methanol contents as the mobile phase, and the six racemates of alprenolol, atenolol, metoprolol, propranolol, clenbuterol, and mianserin were selected as model solutes. For the retention modeling, the most important term was the methanol fraction followed by the temperature and pressure. Significant differences (p<0.05) between most of the coefficients in the retention models were observed when comparing models from set and actual conditions. The selectivity was much less affected by operational changes, and therefore was not severely affected by difference between set and actual conditions. The temperature differences were usually small, maximum +/- 1.4 degrees C, whereas the pressure differences were larger, typically approximately +10.5 bar. The set and actual fractions of methanol also differed, usually by +/- 0.4 percentage points. A cautious conclusion is that the primary reason for the discrepancy between the models is a mismatch between the set and actual methanol fractions. This mismatch is more serious in retention models at low methanol fractions. The study demonstrates that the actual conditions should almost always be preferred. (C) 2017 Elsevier B.V. All rights reserved.
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| 16. |
- Friberg, Henrik, 1965-
(författare)
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Historielärares klassrumsbedömningar : Innehåll och roll i ett historiedidaktiskt perspektiv
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Assessment is a permanent part of history teaching, and the interest in assessment is highly current in the Swedish educational system. One aspect is formative assessment and feedback as a tool for learning; another aspect is that assessment tends to be more and more formalized.Earlier research on written assignments and tests show that history teachers often focus on assessing history knowledge as content and memorizing school textbook. Thus the risk is that history education and assessment does not correspond to the new curricula and rating scale with a wider range of goals.This study investigates the ongoing assessment in the history classroom, frequently entitled ”the black box”. Four history teachers in Swedish upper secondary school were interviewed about assessment, and their classroom assessments in a series of lessons were observed and recorded. The requested historical competencies in teachers´ questioning and feedback are interpreted through the concepts of the historical thinking tradition. Similarities and differences are discussed.Results show a great variety in questioning and feedback. Closed questions are present, but are not in majority, and encouraging feedback is more frequent than rejective. All teachers have the same principle – first order concepts or content come first, then second order concepts or thinking about the first order concepts. Among the second order concepts comparision stands as a universal tool to understand content and handle second order concepts. Cause and consequence combined with continuity and change (most focus on change) also appear to be common in the classroom assessements. More rare are historical persectives and significance. Most teachers consider the classroom assessment as valuable chances to get to know pupils´ history knowledge, but one teacher consider the ongoing pupils’ statements as far more reliable than the written ones, when it comes to grading.The over all result indicates that classroom assessments can involve more than history knowledge as memorized content like single facts.
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| 17. |
- Fridén, Mikael E, 1984-, et al.
(författare)
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Evaluation and analysis of environmentally sustainable methodologies for extraction of betulin from birch bark with a focus on industrial feasibility
- 2016
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 18:2, s. 516-523
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Tidskriftsartikel (refereegranskat)abstract
- Betulin from birch bark was extracted using two principally different extraction methodologies - classical Reflux Boiling (RB) and Pressurized Liquid Extraction (PLE). The extraction methods were analyzed based on both recovery and purity as well as for RB industrial feasibility. The purity and recovery for the different extraction methods were analyzed using High Performance Liquid Chromatography (HPLC) coupled with three different detection principles: Diode Array Detection (DAD), Mass Spectrometry (MS) and Charged Aerosol Detection (CAD). The chromatographic purity was determined by all detections whereas the DAD was used also for complementary gravimetric calculations of the purity of the extracts. The MS detection (in MS and MS/MS modes) was mainly used to characterize the impurities. Two steps to increase the purity of RB extracts were evaluated - pre-boiling the bark in water and precipitation by adding water to the extract. Finally, the methods were compared in terms of amounts of betulin produced and solvent consumed. The RB method including a precipitation step produced the highest purity of betulin. However, results indicate that PLE using three cycles with the precipitation step gives similar purities as for RB. The PLE method produced up to 1.6 times higher amount of extract compared to the RB method. However, the solvent consumption (liter solvent per gram product) for PLE was around 4.5 times higher as compared to the classical RB. PLE performed with only one extraction cycle gave results more similar to RB with 1.2 times higher yield and 1.4 times higher solvent consumption. The RB process was investigated on an industrial scale using a model approach and several important key-factors could be identified. The most energy demanding step was the recycling of extraction solvent which motivates that solvent consumption should be kept low and calculations show a great putative energy reduction by decreasing the ethanol concentration used in the RB process to lower than 90%.
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| 18. |
- Geyer, Holly L., et al.
(författare)
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Associations between gender, disease features and symptom burden in patients with myeloproliferative neoplasms : an analysis by the MPN QOL International Working Group
- 2017
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Ingår i: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 102:1, s. 85-93
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Tidskriftsartikel (refereegranskat)abstract
- The myeloproliferative neoplasms, including polycythemia vera, essential thrombocythemia and myelofibrosis, are distinguished by their debilitating symptom profiles, life-threatening complications and profound impact on quality of life. The role gender plays in the symptomatology of myeloproliferative neoplasms remains under-investigated. In this study we evaluated how gender relates to patients' characteristics, disease complications and overall symptom expression. A total of 2,006 patients (polycythemia vera=711, essential thrombocythemia=830, myelofibrosis=460, unknown=5) were prospectively evaluated, with patients completing the Myeloproliferative Neoplasm-Symptom Assessment Form and Brief Fatigue Inventory Patient Reported Outcome tools. Information on the individual patients' characteristics, disease complications and laboratory data was collected. Consistent with known literature, most female patients were more likely to have essential thrombocythemia (48.6% versus 33.0%; P<0.001) and most male patients were more likely to have polycythemia vera (41.8% versus 30.3%; P<0.001). The rate of thrombocytopenia was higher among males than females (13.9% versus 8.2%; P<0.001) and males also had greater red-blood cell transfusion requirements (7.3% versus 4.9%; P=0.02) with shorter mean disease duration (6.4 versus 7.2 years, P=0.03). Despite there being no statistical differences in risk scores, receipt of most therapies or prior complications (hemorrhage, thrombosis), females had more severe and more frequent symptoms for most individual symptoms, along with overall total symptom score (22.8 versus 20.3; P<0.001). Females had particularly high scores for abdominal-related symptoms (abdominal pain/discomfort) and microvascular symptoms (headache, fatigue, insomnia, concentration difficulties, dizziness; all P<0.01). Despite complaining of more severe symptom burden, females had similar quality of life scores to those of males. The results of this study suggest that gender contributes to the heterogeneity of myeloproliferative neoplasms by influencing phenotypic profiles and symptom expression.
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| 19. |
- Geyer, Holly L., et al.
(författare)
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The role of sexuality symptoms in myeloproliferative neoplasm symptom burden and quality of life : An analysis by the MPN QOL International Study Group
- 2016
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Ingår i: Cancer. - : Wiley. - 0008-543X .- 1097-0142. ; 122:12, s. 1888-1896
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUNDPatients with myeloproliferative neoplasms (MPNs) including polycythemia vera, essential thrombocythemia, and myelofibrosis, are faced with oppressive symptom profiles that compromise daily functioning and quality of life. Among these symptoms, sexuality-related symptoms have emerged as particularly prominent and largely unaddressed. In the current study, the authors evaluated how sexuality symptoms from MPN relate to other patient characteristics, disease features, treatments, and symptoms. METHODSA total of 1971 patients with MPN (827 with essential thrombocythemia, 682 with polycythemia vera, 456 with myelofibrosis, and 6 classified as other) were prospectively evaluated and patient responses to the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC-QLQ C30) were collected, along with information regarding individual disease characteristics and laboratory data. Sexuality scores were compared with an age-matched, healthy control population. RESULTSOverall, patients with MPN were found to have greater sexual dysfunction compared with the healthy population (MPN-SAF score of 3.6 vs 2.0; P<.001), with 64% of patients with MPN describing some degree of sexual dysfunction and 43% experiencing severe symptoms. The presence of sexual symptoms correlated closely with all domains of patient functionality (physical, social, cognitive, emotional, and role functioning) and were associated with a reduced quality of life. Sexual problems also were found to be associated with other MPN symptoms, particularly depression and nocturnal and microvascular-related symptoms. Sexual dysfunction was more severe in patients aged >65 years and in those with cytopenias and transfusion requirements, and those receiving certain therapies such as immunomodulators or steroids. ConclusionsThe results of the current study identify the topic of sexuality as a prominent issue for the MPN population, and this area would appear to benefit from additional investigation and management. Cancer 2016;122:1888-96. (c) 2016 American Cancer Society. Sexuality problems impact all domains of functionality, depression, microvascular symptoms, and overall quality of life among patients with myeloproliferative neoplasms. These problems correlate with patient age, the presence of cytopenias, transfusion requirements, and common therapies for myeloproliferative neoplasms. See also pages 1804-6.
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| 20. |
- Geyer, Holly, et al.
(författare)
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Symptomatic Profiles of Patients With Polycythemia Vera : Implications of Inadequately Controlled Disease
- 2016
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Ingår i: Journal of Clinical Oncology. - 0732-183X .- 1527-7755. ; 34:2, s. 151-
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) associated with disabling symptoms and a heightened risk of life-threatening complications. Recent studies have demonstrated the effectiveness of JAK inhibitor therapy in patients with PV patients who have a history of prior hydroxyurea (HU) use (including resistance or intolerance), phlebotomy requirements, and palpable splenomegaly. We aimed to determine how these features contribute alone and in aggregate to the PV symptom burden.PATIENTS AND METHODS: Through prospective evaluation of 1,334 patients with PV who had characterized symptom burden, we assessed patient demographics, laboratory data, and the presence of splenomegaly by disease feature (ie, known HU use, known phlebotomy requirements, splenomegaly).RESULTS: The presence of each feature in itself is associated with a moderately high symptom burden (MPN symptom assessment form [SAF] total symptom score [TSS] range, 27.7 to 29.2) that persists independent of PV risk category. In addition, symptoms incrementally increase in severity with the addition of other features. Patients with PV who had all three features (PV-HUPS) faced the highest total score (MPN-SAF TSS, 32.5) but had similar individual symptom scores to patients with known HU use (PV-HU), known phlebotomy (PV-P), and splenomegaly (PV-S).CONCLUSION: The results of this study suggest that patients with PV who have any one of the features in question (known HU use, known phlebotomy, or splenomegaly) have significant PV-associated symptoms. Furthermore, it demonstrates that many PV symptoms remain severe independent of the number of features present.
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| 21. |
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| 22. |
- Häggbom, Jannica, et al.
(författare)
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Miljöledning i staten 2016 : En redovisning
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- För verksamhetsåret 2016 har samtliga 185 myndigheter som omfattas avförordning (2009:907) om miljöledning i statliga myndigheter2redovisat tillNaturvårdsverket. Sammanlagt innebär det att miljöledning genomsyrar verksamheter av mycket olika slag.Utmärkande i redovisning av 2016 års miljöledningsarbete är ökningen av ställda miljökrav i samband med upphandlingar hos myndigheterna. Totala upphandlingsvärdet var ca 76 miljarder kronor var av 58 miljarder med miljökrav, vilket motsvarar 76 procent. Detta är en ökning med 16 procentenheter jämfört med 2015.Lagefterlevnaden är god bland myndigheterna. Majoriteten redovisar alla uppgifter enligt bilagan till miljöledningsförordningen och visar att miljöledning spelar en viktig roll i miljöarbetet. Det finns ändå behov av fortsatt arbete med att öka datakvaliteten och fullständigheten i rapporteringen.Under 2016 har ytterligare två myndigheter certifierat sin verksamhet vilket innebär att sammanlagt 42 myndigheter har redovisat att deras verksamhet helt eller delvis är certifierade enligt ISO 14001 eller annat tredjepartsgranskat system.Omkring 80 myndigheter har redovisat mål för både sin direkta och indirekta miljöpåverkan och inkluderat mål för miljökrav i upphandling, endast 9 myndigheter har inte redovisat några mål för år 2016. Ungefär en tredjedel av de myndigheter som får ha ett förenklat miljöledningssystem har ändå satt mål för den indirekta miljöpåverkan. Många goda exempel finns på tydliga målstrukturer och åtgärder för att bidra till positiv miljöpåverkan via sin verksamhetsutövning bland redovisningarna.Vi har valt att särskilt lyfta fram länsstyrelserna i årets redovisning mot bakgrund av deras centrala roll i miljöarbetet på regional nivå. Fokus ligger på åtgärdsarbetet men även länsstyrelsegemensam statistik har tagits fram.Länsstyrelsernas indirekta positiva påverkan är omfattande, bl.a. via de regionala åtgärdsprogrammen för att nå miljökvalitetsmålen samt tillsyn, prövning, områdesskydd och ekonomisk stödgivning. Dessutom genomför länsstyrelserna riktadeinformationsinsatser samt håller utbildningar och rådgivningar till kommuner, näringsliv och organisationer i länet.Allt fler myndigheter rapporterar in sin användning av resfria möten. Det senaste året har det skett en ökning från i snitt 6 till 11 resfria möten per anställd och år. Vid en jämförelse mellan antal resfria möten och antalet resor ser man att myndigheterna i snitt reser dubbelt så ofta som man har ett resfritt möte. Bland de myndigheter som deltagit under flera år i REMM-projektet har man i snitt något fler resfria möten än resor. REMM-myndigheterna har minskat sinakoldioxidutsläpp från resande med 23 procent under en femårsperiod, vilket kan jämföras med en minskning på 4 procent bland de övriga myndigheterna.Totala utsläppen av koldioxid från resor och transporter var ca 372 000 ton 2016,en minskning med ca 2 600 ton, vilket motsvarar 520 varv runt jorden med bil3. Utsläpp från flyg, bil och buss visar en viss minskning jämfört med år 2015.Myndigheternas sammanlagda redovisade energianvändning från verksamhetsel, fastighetsel, värme och kyla är ca 2,7 TWh, dvs. i princip oförändrat sedan år 2015. Hälften av myndigheterna anger att de har minskat energianvändningen, vilket inte syns i statistiken. 49 myndigheter har redovisat att de har 100 procent förnybar energi, 124 stycken att de helt eller delvis ställer krav på produktionsspecificerad förnybar el och 42 stycken att de helt eller delvis sitter i miljöklassade byggnader.Medelvärdet i rankingen är 14 poäng, samma som år 2015, men medianvärdet har ökat med en poäng. 20 myndigheter har höjt och 16 myndigheter har sänkt sin samlade poäng. Drygt hälften av myndigheter med någon form av certifiering, ligger mellan 18 och 22 poäng. Resultatet visar att 34 myndigheter har höga poängvärden för samtliga kriterier (mål, åtgärder och måluppfyllelse).Slutsatsen är att myndigheternas systematiska miljöledningsarbete även i år har utvecklats och förbättrats. Detta är väl i överenstämmelse med miljöledningsförordningens syfte som är att skapa förutsättningar för ett integrerat miljöarbete i myndigheternas verksamhet där miljöfrågorna blir ett naturligt inslag i det dagliga arbetet, såväl i det strategiska som i det operativa arbetet. Att myndigheternas koldioxidutsläpp endast har minskat något och energianvändningen ligger kvar på samma nivå som 2015 visar att ett fortsatt aktivt åtgärdsarbete behövs.Myndigheterna bedriver ett omfattande åtgärdsarbete för att bidra till att nationella och internationella miljömål ska nås. Detta arbete rapporteras, utvärderas och redovisas i flera olika sammanhang. Vi ser att det finns samordningsvinster, både gällande resurser och kvalitet, av att samordna och samutnyttja dessa olika underlag, både inom myndigheterna inför redovisningarna och nationellt i samband med olika typer av utvärderingar. Dessutom finns behov av att se över och samordna redovisningskraven.
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| 23. |
- Janelidze, Shorena, et al.
(författare)
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IL-8 is associated with anxiety in suicidal patients: genotypes and biological measures in cerebrospinal fluid and plasma
- 2015
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley. - 0001-690X .- 1600-0447. ; 131:4, s. 269-278
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Tidskriftsartikel (refereegranskat)abstract
- Objective Recent studies indicate that inflammation may play a role in the pathophysiology of suicidality. Interleukin-8 (IL-8) is a chemokine that in addition to its function in the immune system also exert neuroprotective properties. The involvement of this chemokine in neuropsychiatric conditions is incompletely known. Method We measured plasma and cerebrospinal fluid (CSF) IL-8, as well as the genotype frequency of a single nucleotide polymorphism (-251A/T, rs4073) in the promoter region of the IL8 gene, in suicide attempters (n = 206) and healthy controls (n = 578). Results Plasma and CSF levels of IL-8 were significantly lower in suicide attempters with anxiety than in healthy controls. IL-8 in both plasma and CSF correlated negatively with symptoms of anxiety. Compared with the population-based cohort, the IL-8-251T allele was more prevalent among female suicide attempters. Furthermore, suicide attempters carrying this allele showed more severe anxiety. This correlative study warrants further mechanistic studies on the effects of IL-8 in the central nervous system. Conclusion We suggest that IL-8 might be involved in the biological mechanisms mediating resilience to anxiety. Thus, our findings highlight the chemokine IL-8 as a potential target for future development of anti-anxiety treatments and suicide prevention.
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| 24. |
- Janelidze, Shorena, et al.
(författare)
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Low IL-8 is associated with anxiety in suicidal patients: genetic variation and decreased protein levels
- 2015
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Ingår i: Acta Psychiatrica Scandinavica. - : Wiley: 12 months. - 0001-690X .- 1600-0447. ; 131:4, s. 269-278
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveRecent studies indicate that inflammation may play a role in the pathophysiology of suicidality. Interleukin-8 (IL-8) is a chemokine that in addition to its function in the immune system also exert neuroprotective properties. The involvement of this chemokine in neuropsychiatric conditions is incompletely known. MethodWe measured plasma and cerebrospinal fluid (CSF) IL-8, as well as the genotype frequency of a single nucleotide polymorphism (-251A/T, rs4073) in the promoter region of the IL8 gene, in suicide attempters (n=206) and healthy controls (n=578). ResultsPlasma and CSF levels of IL-8 were significantly lower in suicide attempters with anxiety than in healthy controls. IL-8 in both plasma and CSF correlated negatively with symptoms of anxiety. Compared with the population-based cohort, the IL-8-251T allele was more prevalent among female suicide attempters. Furthermore, suicide attempters carrying this allele showed more severe anxiety. This correlative study warrants further mechanistic studies on the effects of IL-8 in the central nervous system. ConclusionWe suggest that IL-8 might be involved in the biological mechanisms mediating resilience to anxiety. Thus, our findings highlight the chemokine IL-8 as a potential target for future development of anti-anxiety treatments and suicide prevention.
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| 25. |
- Lesko, Marek, et al.
(författare)
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Choice of Model for Estimation of Adsorption Isotherm Parameters in Gradient Elution Preparative Liquid Chromatography
- 2015
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Ingår i: Chromatographia. - : Springer Berlin/Heidelberg. - 0009-5893 .- 1612-1112. ; 78:19-20, s. 1293-1297
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Tidskriftsartikel (refereegranskat)abstract
- The inverse method is a numerical method for fast estimation of adsorption isotherm parameters directly from a few overloaded elution profiles and it was recently extended to adsorption isotherm acquisition in gradient elution conditions. However, the inverse method in gradient elution is cumbersome due to the complex adsorption isotherm models found in gradient elution. In this case, physicochemically correct adsorption models have very long calculation times. The aim of this study is to investigate the possibility of using a less complex adsorption isotherm model, with fewer adjustable parameters, but with preserved/acceptable predictive abilities. We found that equal or better agreement between experimental and predicted elution profiles could be achieved with less complex models. By being able to select a model with fewer adjustable parameters, the calculation times can be reduced by at least a factor of 10.
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| 26. |
- Magnéli, Martin, et al.
(författare)
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Validation of adverse events after hip arthroplasty : a Swedish multi-centre cohort study.
- 2019
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Preventing adverse events (AEs) after orthopaedic surgery is a field with great room for improvement. A Swedish instrument for measuring AEs after hip arthroplasty based on administrative data from the national patient register is used by both the Swedish Hip Arthroplasty Register and the Swedish Association of Local Authorities and Regions. It has never been validated and its accuracy is unknown. The aim of this study was to validate the instrument's ability to detect AEs, and to calculate the incidence of AEs following primary hip arthroplasties.DESIGN: Retrospective cohort study using retrospective record review with Global Trigger Tool methodology in combination with register data.SETTING: 24 different hospitals in four major regions of Sweden.PARTICIPANTS: 2000 patients with either total or hemi-hip arthroplasty were recruited from the SHAR. We included both acute and elective patients.PRIMARY AND SECONDARY OUTCOME MEASURES: The sensitivity and specificity of the instrument. Adjusted cumulative incidence and incidence rate.RESULTS: The sensitivity for all identified AEs was 5.7% (95% CI: 4.9% to 6.7%) for 30 days and 14.8% (95% CI: 8.2 to 24.3) for 90 days, and the specificity was 95.2% (95% CI: 93.5% to 96.6%) for 30 days and 92.1% (95% CI: 89.9% to 93.8%) for 90 days. The adjusted cumulative incidence for all AEs was 28.4% (95% CI: 25.0% to 32.3%) for 30 days and 29.5% (95% CI: 26.0% to 33.8%) for 90 days. The incidence rate was 0.43 AEs per person-month (95% CI: 0.39 to 0.47).CONCLUSIONS: The AE incidence was high, and most AEs occurred within the first 30 days. The instrument sensitivity for AEs was very low for both 30 and 90 days, but the specificity was high for both 30 and 90 days. The studied instrument is insufficient for valid measurements of AEs after hip arthroplasty.
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| 27. |
- Magnuson, Martin, 1965-, et al.
(författare)
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Compositional dependence of epitaxial Tin+1SiCn MAX-phase thin films grown from a Ti3SiC2 compound target
- 2019
-
Ingår i: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films. - : American Institute of Physics (AIP). - 0734-2101 .- 1520-8559. ; 37:2
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Tidskriftsartikel (refereegranskat)abstract
- The authors investigate sputtering of a Ti3SiC2 compound target at temperatures ranging from RT (no applied external heating) to 970 °C as well as the influence of the sputtering power at 850 °C for the deposition of Ti3SiC2 films on Al2O3(0001) substrates. Elemental composition obtained from time-of-flight energy elastic recoil detection analysis shows an excess of carbon in all films, which is explained by differences in the angular distribution between C, Si, and Ti, where C scatters the least during sputtering. The oxygen content is 2.6 at. % in the film deposited at RT and decreases with increasing deposition temperature, showing that higher temperatures favor high purity films. Chemical bonding analysis by x-ray photoelectron spectroscopy shows C–Ti and Si–C bonding in the Ti3SiC2 films and Si–Si bonding in the Ti3SiC2 compound target. X-ray diffraction reveals that the phases Ti3SiC2, Ti4SiC3, and Ti7Si2C5 can be deposited from a Ti3SiC2 compound target at substrate temperatures above 850 °C and with the growth of TiC and the Nowotny phase Ti5Si3Cx at lower temperatures. High-resolution scanning transmission electron microscopy shows epitaxial growth of Ti3SiC2, Ti4SiC3, and Ti7Si2C5 on TiC at 970 °C. Four-point probe resistivity measurements give values in the range ∼120 to ∼450 μΩ cm and with the lowest values obtained for films containing Ti3SiC2, Ti4SiC3, and Ti7Si2C5.
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| 28. |
- Magnuson, Martin, 1965-, et al.
(författare)
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Reactive magnetron sputtering of tungsten target in krypton/trimethylboron atmosphere
- 2019
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Ingår i: Thin Solid Films. - : Elsevier. - 0040-6090 .- 1879-2731. ; 688
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Tidskriftsartikel (refereegranskat)abstract
- W-B-C films were deposited on Si(100) substrates held at elevated temperature by reactive sputtering from a W target in Kr/trimethylboron (TMB) plasmas. Quantitative analysis by Xray photoelectron spectroscopy (XPS) shows that the films are W-rich between ~ 73 and ~ 93 at.% W. The highest metal content is detected in the film deposited with 1 sccm TMB. The C and B concentrations increase with increasing TMB flow to a maximum of ~18 and ~7 at.%, respectively, while the O content remains nearly constant at 2-3 at.%. Chemical bonding structure analysis performed after samples sputter-cleaning reveals C-W and B-W bonding and no detectable W-O bonds. During film growth with 5 sccm TMB and 500 o C or with 10 sccm TMB and 300-600 o C thin film X-ray diffraction shows the formation of cubic 100-oriented WC1-x with a possible solid solution of B. Lower flows and lower growth temperatures favor growth of W and W2C, respectively. Depositions at 700 and 800 o C result in the formation of WSi2 due to a reaction with the substrate. At 900 o C, XPS analysis shows ~96 at.% Si in the film due to Si interdiffusion. Scanning electron microscopy images reveal a fine-grained microstructure for the deposited WC1-x films. Nanoindentation gives hardness values in the range from ~23 to ~31 GPa and reduced elastic moduli between ~220 and 280 GPa in the films deposited at temperatures lower than 600 o C. At higher growth temperatures the hardness decreases by a factor of 3 to 4 following the formation of WSi2 at 700-800 o C and Si-rich surface at 900 o C.
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| 29. |
- Martín-Rodríguez, Saúl, et al.
(författare)
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Is tensiomyography a useful assessment tool in sports medicine?
- 2017
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Ingår i: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA. - : Springer Science and Business Media LLC. - 1433-7347. ; 25:12, s. 3980-3981
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 30. |
- Olofsson, Hans, 1960-
(författare)
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Historia på högstadiet : Historiekulturella yttringar i och utanför ett klassrum i Sverige hösten 2009
- 2019
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- How do students use schools´ history education to develop their historical consciousness? In which ways could history education be regarded as a historical-culture expression, i.e. as a part of a society’s interest in the past? This thesis takes its point of departure in these overarching questions. More specifically the research was carried out as a contextualised case study of sixteen history lessons in a Swedish Year 9 class, in the autumn of 2009. The contextualisation consists of an analysis on historical-culture expressions in Sweden at that time. Despite conflicting opinions, the major finding was the common view of Sweden as a country that solves her problems in a peaceful way, both in the past, the present and the future. The classroom study was conducted with an ethnographical approach with close attention to teacher-student interactions. The research was guided by an analytical model inspired by the historian Jörn Rüsen’s theories on history learning processes.The results show in detail the complicated learning processes in the classroom but also the connection with the historical-culture expressions in Sweden at that moment. One major finding was the tendency to react to the rise of contemporary islamophobia and nationalism in Sweden by making comparisons with the development in Weimar Germany in the beginning of the 1930s. This tendency was present both in and outside the classroom.
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| 31. |
- Samuelsson, Jörgen, 1971-, et al.
(författare)
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Optimizing Column Length and Particle Size in Preparative Batch Chromatography Using Enantiomeric Separations of Omeprazole and Etiracetam as Models : Feasibility of Taguchi Empirical Optimization
- 2018
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Ingår i: Chromatographia. - Heidelberg : Springer. - 0009-5893 .- 1612-1112. ; 81:6, s. 851-860
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Tidskriftsartikel (refereegranskat)abstract
- The overreaching purpose of this study is to evaluate new approaches for determining the optimal operational and column conditions in chromatography laboratories, i.e., how best to select a packing material of proper particle size and how to determine the proper length of the column bed after selecting particle size. As model compounds, we chose two chiral drugs for preparative separation: omeprazole and etiracetam. In each case, two maximum allowed pressure drops were assumed: 80 and 200 bar. The processes were numerically optimized (mechanistic modeling) with a general rate model using a global optimization method. The numerical predictions were experimentally verified at both analytical and pilot scales. The lower allowed pressure drop represents the use of standard equipment, while the higher allowed drop represents more modern equipment. For both compounds, maximum productivity was achieved using short columns packed with small-particle size packing materials. Increasing the allowed backpressure in the separation leads to an increased productivity and reduced solvent consumption. As advanced numerical calculations might not be available in the laboratory, we also investigated a statistically based approach, i.e., the Taguchi method (empirical modeling), for finding the optimal decision variables and compared it with advanced mechanistic modeling. The Taguchi method predicted that shorter columns packed with smaller particles would be preferred over longer columns packed with larger particles. We conclude that the simpler optimization tool, i.e., the Taguchi method, can be used to obtain “good enough” preparative separations, though for accurate processes, optimization, and to determine optimal operational conditions, classical numerical optimization is still necessary
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| 32. |
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| 33. |
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| 34. |
- Schwieler, L., et al.
(författare)
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Electroconvulsive therapy suppresses the neurotoxic branch of the kynurenine pathway in treatment-resistant depressed patients
- 2016
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Ingår i: Journal of Neuroinflammation. - : Springer Science and Business Media LLC. - 1742-2094. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Neuroinflammation is increasingly recognized as contributing to the pathogenesis of depression. Key inflammatory markers as well as kynurenic acid (KYNA) and quinolinic acid (QUIN), both tryptophan metabolites, have been associated with depressive symptoms and suicidality. The aim of the present study is to investigate the peripheral concentration of cytokines and tryptophan and kynurenine metabolites in patients with unipolar treatment-resistant depression before and after electroconvulsive therapy (ECT), the most effective treatment for depression. Methods: Cytokines in plasma from patients with major depressive disorder (MDD; n = 19) and healthy volunteers (n = 14) were analyzed with electrochemiluminescence detection. Tryptophan and kynurenine metabolites were detected with high-performance liquid chromatography (HPLC) and LC/MS. KYNA was analyzed in a second healthy control cohort (n = 22). Results: Patients with MDD had increased plasma levels of interleukin (IL)-6 compared to healthy volunteers (P < 0.05). We also found an altered kynurenine metabolism in these patients displayed by decreased plasma levels of KYNA (P < 0.0001) as well as a significantly increased QUIN/KYNA ratio (P < 0.001). Plasma levels of tryptophan, kynurenine, and QUIN did not differ between patients and controls. Treatment with ECT was associated with a significant decrease in the plasma levels of tryptophan (P < 0.05), kynurenine (P < 0.01), and QUIN (P < 0.001), whereas plasma levels of KYNA did not change. The QUIN/KYNA ratio was found to significantly decrease in ECT-treated patients (P < 0.05). There was a significant inverse correlation between symptom severity and kynurenine levels at baseline (r = -0.67, P = 0.002). Conclusions: This study confirms an imbalanced kynurenine pathway in MDD supporting the hypothesis of a netstimulation of N-methyl-D-aspartic acid (NMDA) receptors in the disorder. Treatment with ECT profoundly decreased QUIN, an NMDA-receptor agonist previously suggested to be implicated in the pathogenesis of depression, an effect that might have bearing for the good clinical outcome of ECT.
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| 35. |
- Schwieler, Lilly, et al.
(författare)
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Increased levels of IL-6 in the cerebrospinal fluid of patients with chronic schizophrenia - significance for activation of the kynurenine pathway.
- 2015
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Ingår i: Journal of Psychiatry & Neuroscience. - : CMA-CANADIAN MEDICAL ASSOC. - 1180-4882 .- 1488-2434. ; 40:2, s. 126-13
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Accumulating evidence indicates that schizophrenia is associated with brain immune activation. While a number of reports suggest increased cytokine levels in patients with schizophrenia, many of these studies have been limited by their focus on peripheral cytokines or confounded by various antipsychotic treatments. Here, well-characterized patients with schizophrenia, all receiving olanzapine treatment, and healthy volunteers were analyzed with regard to cerebrospinal fluid (CSF) levels of cytokines. We correlated the CSF cytokine levels to previously analyzed metabolites of the kynurenine (KYN) pathway.METHODS: We analyzed the CSF from patients and controls using electrochemiluminescence detection with regard to cytokines. Cell culture media from human cortical astrocytes were analyzed for KYN and kynurenic acid (KYNA) using high-pressure liquid chromatography or liquid chromatography/mass spectrometry.RESULTS: We included 23 patients and 37 controls in our study. Patients with schizophrenia had increased CSF levels of interleukin (IL)-6 compared with healthy volunteers. In patients, we also observed a positive correlation between IL-6 and the tryptophan:KYNA ratio, indicating that IL-6 activates the KYN pathway. In line with this, application of IL-6 to cultured human astrocytes increased cell medium concentration of KYNA.LIMITATIONS: The CSF samples had been frozen and thawed twice before analysis of cytokines. Median age differed between patients and controls. When appropriate, all present analyses were adjusted for age.CONCLUSION: We have shown that IL-6, KYN and KYNA are elevated in patients with chronic schizophrenia, strengthening the idea of brain immune activation in patients with this disease. Our concurrent cell culture and clinical findings suggest that IL-6 induces the KYN pathway, leading to increased production of the N-methyl-D-aspartate receptor antagonist KYNA in patients with schizophrenia.
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| 36. |
- Scotch, Allison H, et al.
(författare)
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Symptom burden profile in myelofibrosis patients with thrombocytopenia : Lessons and unmet needs
- 2017
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Ingår i: Leukemia Research. - : Elsevier BV. - 0145-2126 .- 1873-5835. ; 63, s. 34-40
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Tidskriftsartikel (refereegranskat)abstract
- Myelofibrosis is a myeloproliferative neoplasm associated with progressive cytopenias and high symptom burden. MF patients with thrombocytopenia have poor prognosis but the presence of thrombocytopenia frequently precludes the use of JAK2 inhibitors. In this study, we assessed quality of life and symptom burden in 418 MF patients with (n = 89) and without (n = 329) thrombocytopenia using prospective data from the MPN-QOL study group database, including the Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) and Total Symptom Score (MPN10). Thrombocytopenia, defined as platelet count < 100 x10(9)/L (moderate 51-100 x 10(9)/L; severe <= 50 x10(9)/L), was associated with anemia (76% vs. 45%, p < 0.001), leukopenia (29% vs. 11%, p < 0.001), and need for red blood cell transfusion (35% vs. 19%, p = 0.002). Thrombocytopenic patients had more fatigue, early satiety, inactivity, dizziness, sad mood, cough, night sweats, itching, fever, and weight loss; total symptom scores were also higher (33 vs. 24, p < 0.001). Patients with severe thrombocytopenia were more likely to have anemia (86% vs. 67%, p = 0.04), leukopenia (40% vs. 20%, p = 0.04), and transfusion requirements (51% vs. 20%, p = 0.002) but few differences in symptoms when compared to patients with moderate thrombocytopenia. These results suggest that MF patients with thrombocytopenia experience greater symptomatic burden than MF patients without thrombocytopenia and may benefit from additional therapies.
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| 37. |
- Seitz, Arne, et al.
(författare)
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Concept validation study for fuselage wake-filling propulsion integration
- 2018
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Ingår i: 31st Congress of the International Council of the Aeronautical Sciences, ICAS 2018.
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Konferensbidrag (refereegranskat)abstract
- The present paper provides an overview together with intermediate results of the work-in-progress research performed in the EC-funded Horizon 2020 collaborative project CENTRELINE (“ConcEpt validatioN sTudy foR fusElage wake-filLIng propulsioN integration”), aiming at demonstrating the proof of concept for a groundbreaking approach to synergistic propulsion-airframe integration, the so-called Propulsive Fuselage Concept (PFC). The concept features a turbo-electrically driven propulsive device integrated in the very aft-section of the fuselage, dedicated to the purpose of fuselage wake-filling. Currently at TRL 1-2, CENTRELINE's target is to mature the technological key features of the PFC to TRL 3-4. The core of the targeted proof-of-concept is formed by two experimental test campaigns supported by high-fidelity 3D numerical simulation and integrated multidisciplinary design optimisation techniques for aerodynamics, aero-structures as well as the energy and propulsion system.
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| 38. |
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| 39. |
- Stolare, Martin, 1969-, et al.
(författare)
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The Swedes and their history
- 2017
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Ingår i: London Review of Education. - London : Routledge. - 1474-8460 .- 1474-8479. ; 15:2, s. 243-258
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Tidskriftsartikel (refereegranskat)
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| 40. |
- Ventorp, Filip, et al.
(författare)
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The CD44 ligand hyaluronic acid is elevated in the cerebrospinal fluid of suicide attempters and is associated with increased blood-brain barrier permeability.
- 2016
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Ingår i: Journal of Affective Disorders. - : Elsevier BV. - 1573-2517 .- 0165-0327. ; 193, s. 349-354
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Tidskriftsartikel (refereegranskat)abstract
- The glycosaminoglycan hyaluronic acid (HA) is an important component of the extracellular matrix (ECM) in the brain. CD44 is a cell adhesion molecule that binds to HA in the ECM and is present on astrocytes, microglia and certain neurons. Cell adhesion molecules have been reported to be involved in anxiety and mood disorders. CD44 levels are decreased in the cerebrospinal fluid (CSF) of depressed individuals, and the CD44 gene has been identified in brain GWAS studies as a possible risk gene for suicidal behavior.
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| 41. |
- Vera, C. M., et al.
(författare)
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A preliminary study on the selectivity of linear polynuclear aromatic hydrocarbons in SFC using phenyl-type stationary phases
- 2015
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Ingår i: Microchemical journal (Print). - : Elsevier. - 0026-265X .- 1095-9149. ; 121, s. 136-140
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Tidskriftsartikel (refereegranskat)abstract
- The retention behaviour of a homologous series of polyaromatic hydrocarbons was evaluated on two phenyl-type stationary phases in reversed phase supercritical fluid chromatography (SFC). These phases were the Synergi polar-RP phase and the Cosmosil 5PBB phase, both of which are polar end-capped and incorporate an ether in a propyl chain that tethers the phenyl ring to the silica surface. The Cosmosil 5PBB phase also has five bromine atoms on the phenyl ring. The retention capacity of the Cosmosil column was substantially greater than the Synergi column. However, selectivity on the Cosmosil column was effectively independent of the acetonitrile modifier composition in the CO2 mobile phase, whereas, selectivity on the Synergi column was greatly affected by the acetonitrile modifier in the CO2 mobile phase. The results from this study showed that selectivity and retention studies in HPLC cannot be used to predict selectivity and retention behaviour in SFC. (C) 2015 Elsevier B.V. All rights reserved.
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| 42. |
- Vera, C. M., et al.
(författare)
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Contrasting selectivity between HPLC and SFC using phenyl-type stationary phases : A study on linear polynuclear aromatic hydrocarbons
- 2015
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Ingår i: Microchemical journal (Print). - : Elsevier. - 0026-265X .- 1095-9149. ; 119, s. 40-43
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Tidskriftsartikel (refereegranskat)abstract
- A selectivity study was undertaken using two types of phenyl-type (Synergi polar RP and Cosmosil 5PBB) stationary phases in supercritical fluid chromatography. The mobile phases used in the SFC environment employed CO2 with methanol as the modifier. These columns were tested using linear polynuclear aromatic hydrocarbons as the test solutes. The retention behaviour of these PAHs in SFC was compared to their behaviour in HPLC and there were very distinct differences. On the Synergi-polar stationary phase the PAH selectivity was highly dependent on the methanol modifier concentration, but in comparison on the Cosmosil column, the selectivity between the members of this PAH test group showed almost no change as a function of the methanol concentration, even though the retentivity on the Cosmosil stationary phase was far greater than the Synergi stationary. In fact, the mobile phase played a very passive role in the separations observed on the Cosmosil stationary phase. (C) 2014 Elsevier B.V. All rights reserved.
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