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  • 1.
    Bylund, Dan
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Henriksson, Anders E.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences. Sundsvalls sjukhus.
    Proteomic approaches to identify circulating biomarkers in patients with abdominal aortic aneurysm2015In: American Journal of Cardiovascular Disease, ISSN 2160-200X, Vol. 5, no 3, p. 140-145Article, review/survey (Refereed)
    Abstract [en]

    Abdominal aortic aneurysm (AAA) is a common condition with high mortality when ruptured. Most clinicians agree that small AAAs are best managed by ultrasonographic surveillance. However, it has been stated in recent reviews that a serum/plasma biomarker that predicts AAA rupture risk would be a powerful tool in stratifying patients with small AAAs. Identification of such circulating biomarkers with traditional hypothesis driven studies has been unsuccessful. In this review we summarize six studies using different proteomic approaches to find new, potential plasma AAA biomarker candidates. In conclusion, by using proteomic approaches novel potential plasma biomarkers for AAA have been identified.

  • 2.
    Bång, Joakim
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of applied science and design.
    Anderbrant, Olle
    Lund Univ, Dept Biol, Lund, Sweden.
    Stereoisomeric separation of derivatized 2-alkanols using gas chromatography – mass spectrometry: Sex pheromone precursors found in pine sawfly species2012In: Analytical Letters, ISSN 0003-2719, E-ISSN 1532-236X, Vol. 45, no 9, p. 1016-1027Article in journal (Refereed)
    Abstract [en]

    Stereoisomers of long-chain secondary alcohols are used as sex pheromone precursors among pine sawflies, which can be severe pest to conifers. To use the pheromone in environmentally friendly pest managements, methods are needed that can determine the exact stereochemistry of the precursor alcohols. Combinations of 11 acid chloride derivatives and 10 GC columns were evaluated for separation of the stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol, 3,7-dimethyltridecan-2-ol, 3,7-dimethyltetradecan-2-ol, and 3,7-dimethylpentadecan-2-ol. Derivatisation with (2S)-2-acetoxypropionyl chloride in combination with the Chiraldex B-PA column separated all eight stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol and 3,7-dimethyltridecan-2-ol. A combination of two different derivatisation methods was needed to separate all stereoisomers of the longer chained alcohols, 3,7-dimethyltetradecan-2-ol and 3,7-dimethylpentadecan-2-ol. An extract of the pine sawfly Neodiprion lecontei was also analysed, and the stereochemistry of the sex pheromone alcohol prcursor was determined to be (2S,3S,7S)-3,7-dimethylpentadecan-2-ol, at an amount of about 7 ng/female. This paper presents the first GC-MS-separation of all eight stereoisomers of 3,7-dimethylundecan-2-ol, 3,7-dimethyldodecan-2-ol and 3,7-dimethyltridecan-2-ol in a single analytical run, and also the first determination of the stereochemistry of the sex pheromone precursor of N. lecontei.

  • 3.
    Fredriksson, Mattias
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Petersson, Patrik
    AstraZeneca.
    Axelsson, Bengt-Olof
    AstraZeneca.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    A component tracking algorithm for accelerated and improved liquid chromatography-mass spectrometry method development2010In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1217, no 52, p. 8195-8204Article in journal (Refereed)
    Abstract [en]

    A method for tracking of sample components during liquid chromatography–mass spectrometry (LC–MS) method development has been proposed. The method manages to, fully automatically and without user intervention, find the chromatographic peaks in the data sets, discriminate them to sample components and track them when the separation conditions have been changed. The algorithm utilises the resolution obtained from all considered data sets and has the ability to discriminate the non informative parts. The technique has a great sensitivity even in cases where a majority of the tracked components cannot easily be spotted by means of traditional total ion chromatogram (TIC) or base peak chromatogram (BPC) representations. The method was tested on an experimental sample using six different columns and an average of 79% of the suggested sample components could be successfully tracked at a minimum area of 0.05% of the main component in the sample. 66 components with 79–92% of the total suggested component area were able to be tracked between all data sets. The method could be used to rapidly investigate selectivity during different types of separation conditions.

  • 4.
    Koptioug, Andrei
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering and Sustainable Development.
    New Transmission Line Resonators for ESE1998In: EPR Newsletter, Vol. 9, no 3, p. 20-22Article in journal (Other academic)
  • 5.
    Koptioug, Andrei
    et al.
    Department of Bio-Medical Physics and Bio-Engineering, University of Aberdeen, Foresterhill, Aberdeen AB9 2ZD, United Kingdom..
    Reijerse, Edward
    Klaassen, A. K.
    New Transmission-Line Resonator for Pulsed EPR1997In: Journal of magnetic resonance, ISSN 1090-7807, E-ISSN 1096-0856, no 125, p. 369-371Article in journal (Refereed)
  • 6.
    Koptyug, Andrey
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Optical Detection of the Radical-Ion Pair Spectra in Weak Magnetic Fields1987In: Doklady Akademii Nauk, ISSN 0869-5652, Vol. 297, no 6, p. 1414-1418Article in journal (Refereed)
  • 7.
    Norström, Sara H
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Vestin, Jenny LK
    Swedish geotechnical institute.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    Influences of dissolved organic carbon on stream water chemistry in two forested catchments in central Sweden2010In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 101, no 1-3, p. 229-241Article in journal (Refereed)
    Abstract [en]

    Stream water chemistry in two headwater streams draining two small, adjacent catchments in Bispgården, central Sweden was studied during the 2003 and 2004 growing seasons. The two catchments closely resemble each other in regard to size, shape and drainage density, with the major difference found in the area of wetland lining the streambeds. The emphasis of the study was to investigate the stream water chemistry of these closely resembling catchments, regarding the quality and quantity of dissolved organic carbon (DOC) and its influence on the concentrations of di- and trivalent cations. The streams showed significant differences in the content and size distribution of DOC and in the distribution of cations between the different size fractions. For both streams the high flow events induced by precipitation influenced the chemistry of the streams through increase of organic matter and its associated cations. Fanbergsbäcken, with relatively low pH and high DOC concentration, had a greater amount of high molecular mass (HMM) DOC to which approximately 75% of Al and Fe and about 50% of Ca and Mg were associated. Gråbergsbäcken, with a higher pH and lower DOC level, had approximately 65% of Al, 40% of Fe and 30% of Ca and Mg associated to its HMM DOC fraction. Sixteen different low molecular mass organic acids were found in the stream water, of which oxalic and lactic acid were present in the highest concentrations.

  • 8.
    Olofsson, Madelen
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    On the investigation of chemical parameters reflecting microbial activity linked to nutrient availability in forest soil2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    As agrarian society developed, the most fertile soils able to sustain the nutritional requirements needed for high crop yield were assigned to farming, while the more penurious soils were left to uphold the forest ecosystems. Some temperate forests are developed on acidic soils considered to be nutrient poor, as much of the inorganic nutrients are entrapped in poorly weatherable soil minerals and not easily accessed by plant roots. In an undisturbed ecosystem, the largest contribution of available nutrients comes from the recycling of organically bound nutrients via the decomposition of dead plant material. If biomass is removed, for instance with a more intensified exploitation of the forest ecosystems including whole tree harvesting, this source of nutrients is consequently decreased. The importance of soil mineral weathering as a source of nutrients, and especially that promoted by soil biota, is thereby emphasized.

    This thesis addresses biotic parameters associated with mineral weathering. Different aspects of soil solution sampling strategies and analysis of different organic ligands as well as biomarkers for the estimation of fungal biomass were investigated. These chemical parameters were also evaluated as indicators of microbial activity in relation to mineral nutrient availability in soil.

    With the assumption that the current nutrient status of a soil will affect the microbial interest of certain minerals as sources of inorganic nutrients, a mineral amendment trial was performed in a Swedish boreal forest soil. Overall, the amended soil presented good nutrient status, but with a possible shortage of iron. Due to this, it was hypothesized that the amended mineral with the highest iron content i.e. biotite would cause an elevation of microbial activity in its vicinity when compared to the bulk soil.

    The level of microbial activity in the vicinity of the amended minerals was evaluated via quantification of organic acids and siderophores, as well as estimation of fungal biomass and enzymatic activity.

    The highest microbial activity was measured for the O horizon of the investigated podzol, although nothing indicated an elevated association with the amended minerals. In the E horizon, however, elevation in microbial activity was observed in the vicinity of the biotite mineral when compared with bulk soil, although only a few of the investigated parameters differed significantly when evaluated separately.  

    To enable this study, a highly sensitive analytical method employing liquid chromatography and mass spectrometry was developed to quantify a number of hydroxamate siderophores. On-line pre-concentration enabled detection of these organic ligands in the pico-molar range – a necessity when analyzing natural samples.

    Furthermore, an analytical method was developed for the estimation of fungal biomass via quantification of chitin-derived glucosamine, which also employed liquid chromatography and tandem mass spectrometry. Unlike currently available methods, the one presented in this thesis did not involve analyte derivatization, which resulted in high sample throughput while simultaneously avoiding complications involved with the additional derivatization procedure.

    The distribution of a group of organic ligands known as aromatic low molecular mass organic acids was also studied in a boreal forest podzol soil. Different sampling and samples preparation techniques, namely tension-lysimeters, soil centrifugation and liquid-soil extraction, were compared when analyzing soil solution components. Significant differences in analyte amount and species type were found between these sampling techniques. Some of the differences could be accounted for by variation in soil composition at different depths of the investigated podzol, but others could be attributed to structural differences within the studied analyte group. This clearly illustrated the intricacy of sampling and analysis when working with a sample matrix as complex and diverse as soil.

    As previously, liquid chromatography and mass spectrometry was used to quantify the analytes of interest. A highly sensitive analytical method was developed that was able to detect eleven aromatic low molecular mass organic acids in the nano-molar range. High selectivity was ensured by applying multiple reaction monitoring enabled by collision induced fragmentation of the analytes.

     

  • 9.
    Olofsson, Madelen
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Analysis of hydroxamate siderophores in soil solution using liquid chromatography with mass spectrometry and tandem mass spectrometry with on-line sample preconcentration2015In: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 38, no 19, p. 3305-3312Article in journal (Refereed)
    Abstract [en]

    A liquid chromatography-electrospray ionization-mass spectrometry method was developed to quantitatively and qualitatively analyze thirteen hydroxamate siderophores (ferrichrome, ferrirubin, ferrirhodin, ferrichrysin, ferricrocin, ferrioxamine B, D1, E and G, neocoprogen I and II, coprogen and triacetylfusarinine C). Samples were pre-concentrated on-line via switch-valve setup prior to analyte separation on a Kinetex C18 column. Gradient elution was performed using a mixture of an ammonium formate buffer and acetonitrile. Total analysis time including column conditioning was 20.5 minutes. Analyte were fragmented by applying collision induced dissociation, enabling structural identification via tandem mass spectrometry. Limit of detection values for the selected ion monitoring method ranged from 71 pM to 1.5 nM with corresponding values of two to nine times higher for the multiple reaction monitoring method. The liquid chromatography-mass spectrometry method resulted in a robust and sensitive quantification of hydroxamate siderophores as indicated by retention time stability, linearity, sensitivity, precision and recovery. The analytical error of the methods, assessed trough random-order, duplicate analysis of soil samples extracted with a mixture of 10 mM phosphate buffer and methanol, appears negligible in relation to between-sample variations. 

  • 10.
    Olofsson, Madelen
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Liquid Chromatography with Electrospray Ionization and Tandem Mass Spectrometry Applied in the Quantitative Analysis of Chitin-Derived Glucosamine for a Rapid Estimation of Fungal Biomass in Soil2016In: International Journal of Analytical Chemistry, ISSN 1687-8760, E-ISSN 1687-8779, article id 9269357Article in journal (Refereed)
    Abstract [en]

    This method employs liquid chromatography-tandem mass spectrometry to rapidly quantify chitin-derived glucosamine for estimating fungal biomass. Analyte retention was achieved using hydrophilic interaction liquid chromatography, with a zwitter-ionic stationary phase (ZIC-HILIC), and isocratic elution using 60 % 5 mM ammonium formate buffer (pH 3.0) and 40 % ACN. Inclusion of muramic acid, and its chromatographic separation from glucosamine, enabled calculation of the bacterial contribution to the latter. Galactosamine, an isobaric isomer to glucosamine, found in significant amounts in soil samples, was also investigated. The two isomers form the same precursor and product ions, and could not be chromatographically separated using this rapid method. Instead, glucosamine and galactosamine were distinguished mathematically, using the linear relationships describing the differences in product ion intensities for the two analytes. The m/z transitions of 180→72 and 180→84 were applied for the detection of glucosamine and galactosamine and that of 252→126 for muramic acid. Limits of detection were in the pico-molar range for all included analytes. The total analysis time was 6 min, providing a high sample through-put method.

  • 11.
    Olofsson, Madelen
    et al.
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Norström, Sara
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Bylund, Dan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Evaluation of sampling and sample preparation procedures for the determination of aromatic acids and their distribution in a podzol soil using liquid chromatography-tandem mass spectrometry2014In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 232-234, p. 373-380Article in journal (Refereed)
    Abstract [en]

    In this work the distribution of free and weekly adsorbed aromatic acids (phthalic acid and ten phenolicacids; gallic, p-hydroxybenzoic, salicylic, vanillic, protocatechuic, p-coumaric, syringic, sinapic, ferulic and caffeicacid), which could participate in weathering and soil formation processes, were studied for O, E and Bhorizons in a podzol soil in central Sweden. For the analysis a simple and rapid quantitative and qualitative liquidchromatography–tandem mass spectrometry method (using gradient elution) was developed with LODs rangingfrom 5 to 25 nM. Different soil solution sampling techniques (tension-lysimeter and soil centrifugation) and soilextraction with either 10 mM phosphate buffer (pH 7.2) or 50:50 (v/v) 10 mM phosphate buffer:MeOHwere compared. All eleven acids were found in detectable or trace concentrations. The most abundant aromaticacids were vanillic and phthalic acid with concentrations around 1 μM for O and E horizon respectively.Lysimeter samples resulted in the lowest concentrations followed by centrifugation samples. Ingeneral, buffer:MeOH extraction resulted in the highest concentrations for the O horizon, likely due toMeOH's ability to compete for hydrophobic sites on soil organic matter (SOM). Then again, pure bufferwith its higher ion strength, interfering with the acids electrostatic interactions with clay particles, leads tohigher extracted concentrations for the E and B horizons. Since the efficiency of the extraction solutions, to alarge extent, depends on the sample properties, a general approach is hard to appoint. However, the extractionof substituted cinnamic acids is in general facilitated by adding MeOH to the extraction solution. The use of statisticalmethods for the evaluation of the results showed a large and significant difference in aromatic acid concentrationsreceived using different sampling techniques and sample preparations. In fact, sampling methodsresulted in higher variations in aromatic acid concentrations than sampled horizon.

  • 12.
    Pokorny, T.
    et al.
    Institute of Sensory Ecology, Heinrich-Department of Animal Ecology, Evolution and Biodiversity, Ruhr University Bochum, 44780 Bochum, Germany .
    Hannibal, M.
    Institute of Sensory Ecology, Heinrich-Heine University Düsseldorf, 40225 Düsseldorf, Germany .
    Quezada-Euan, J. J. G.
    Departamento de Apicultura, Universidad Autónoma de Yucatán, Mérida, Yucatán, 97100, Mexico .
    Hedenström, Erik
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Sjöberg, Natalia
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Bång, Joakim
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences.
    Eltz, T.
    Department of Animal Ecology, Evolution and Biodiversity, Ruhr University Bochum, 44780 Bochum, Germany .
    Acquisition of species-specific perfume blends: Influence of habitat-dependent compound availability on odour choices of male orchid bees (Euglossa spp.)2013In: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 172, no 2, p. 417-425Article in journal (Refereed)
    Abstract [en]

    Male orchid bees (Euglossini, Apidae, Hymenoptera) expose species-specific blends of volatile chemicals (perfume bouquets) during their courtship display. The perfumes are acquired by collecting fragrant substances from environmental sources, which are then accumulated in specialised hind leg pouches. To balance the perfume composition, the males need to find and collect the required substances in specific relative amounts while facing seasonal, local or habitat-dependent differences in compound availability. Experience-dependent choice of odours, i.e. 'learned avoidance' of recently collected components, has been proposed as the mechanism that mediates the accumulation of the stereotypical compound ratios. In the present study, we used the presence of certain compounds in male hind leg pouches as proxy for the respective local compound availability, and investigated whether differences in content are correlated with differences in chemical choice assays. Our results suggest that volatile availability differs between localities (n = 16) as well as habitats (n = 2; coastal vs. inland) across the Yucatán peninsula, Mexico, for both studied species. Male Euglossa dilemma showed a pronounced preference for benzyl benzoate and eugenol at locations where those compounds were rare in hind leg extracts, as predicted by the learned avoidance model. No equivalent correlations were found for Euglossa viridissima. This is the first study to combine chemical analyses of perfumes with bioassays of odour choice. It strengthens the view that negative feedback from collected odours modifies future chemical choice and helps males to acquire specific perfume blends. © 2013 Springer-Verlag Berlin Heidelberg.

  • 13.
    Smits, Mark M
    et al.
    Microbial Ecology, Lund University, Ecology Building, SE-223 62 Lund, Sweden.
    Herrmann, Anke M
    Department of Chemistry, SLU, PO Box 7015, SE-750 07 Uppsala, Sweden.
    Duane, Michael
    Department of Earth and Environmental Sciencea, Faculty of Science, PO Box 5969, Safat 13060, Kuwait.
    Duckworth, Owen W
    Department of Soil Science, North Carolina State University, PO Box 7619, Raleigh, North Carolina, 27695 7619, USA.
    Bonneville, S
    Benning, L G
    Lundström, Ulla S
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Natural Sciences, Engineering and Mathematics.
    The fungal-mineral interface: Challanges and considerations of micro-analytical developments2009In: Fungal Biology Reviews, ISSN 1749-4613, E-ISSN 1878-0253, Vol. 23, no 4, p. 122-131Article in journal (Refereed)
    Abstract [en]

    Over recent years, the role of fungi, especially mycorrhizal fungi, in the weathering of rock-forming minerals has been increasingly recognised. Much of our understanding of the effects of fungi on mineral weathering is based on macroscopic studies. However, the ability of fungi to translocate materials, including organic acids and siderophores, to specific areas of a mineral surface leads to significant spatial heterogeneity in the weathering process. Thus, geomycologists are confronted with unique challenges of how to comprehend and quantify such a high degree of diversity and complicated arrays of interactions. Recent advances in experimental and analytical techniques have increased our ability to probe the fungal-mineral interface at the resolution necessary to decouple significant biogeochemical processes. Modern microscopy, spectroscopy, mass spectrometry, wet chemistry, and scattering techniques allow for the selective extraction of physical, chemical, and structural data at the micro- to nano-scale. These techniques offer exciting possibilities to study fungal-mineral interactions at the scale of individual hyphae. In this review, we give an overview of some of these techniques with their characteristics, advantages and limitations, and how they can be used to further our understanding of biotic mineral weathering.

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