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  • 1.
    Alhouayek, Mireille
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology. Catholic Univ Louvain, Brussels, Belgium.
    Gouveia-Figueira, Sandra
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Swedish Univ Agr Sci, Umea, Sweden.
    Hammarström, Marie-Louise
    Umeå University, Faculty of Medicine, Department of Clinical Microbiology, Clinical Immunology.
    Fowler, Christopher J.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Pharmacology.
    Involvement of CYP1B1 in interferon gamma-induced alterations of epithelial barrier integrity2018In: British Journal of Pharmacology, ISSN 0007-1188, E-ISSN 1476-5381, Vol. 175, no 6, p. 877-890Article in journal (Refereed)
    Abstract [en]

    BACKGROUND AND PURPOSE CYP1B1 and CYP1A1 are important extra-hepatic cytochromes, expressed in the colon and involved in the metabolism of dietary constituents and exogenous compounds. CYP1B1 expression is increased by pro-inflammatory cytokines, and it has been recently implicated in regulation of blood brain barrier function. We investigated its involvement in the increased permeability of the intestinal epithelial barrier observed in inflammatory conditions. EXPERIMENTAL APPROACH Epithelial monolayers formed by human T84 colon carcinoma cells cultured on transwells, were disrupted by incubation with IFN gamma (10 ng.mL(-1)). Monolayer integrity was measured using transepithelial electrical resistance. CYP1A1 and CYP1B1 inhibitors or inducers were applied apically. Potential mechanisms of action were investigated using RT-qPCR. KEY RESULTS IFN gamma disrupts the barrier integrity of the T84 monolayers and increases CYP1B1 and HIF1 alpha mRNA expression. CYP1B1 induction is inhibited by the NF-kappa B inhibitor ammonium pyrrolidinedithiocarbamate (100 mu M) but not by the HIF1 alpha inhibitor 3-(5-hydroxymethyl-2-furyl)-1-benzyl indazole (50 mu M). Inhibition of CYP1B1 with the selective inhibitor 2,4,3,5-tetramethoxystilbene (100 nM) partly reverses the effects of IFN gamma on epithelial permeability. CONCLUSIONS AND IMPLICATIONS These data suggest that increased expression of CYP1B1 is involved in the effects of IFN gamma on epithelial permeability. Inhibition of CYP1B1 counteracts the alterations of epithelial barrier integrity induced by IFN gamma and could thus have a therapeutic potential in disorders of intestinal permeability associated with inflammation.

  • 2.
    Babaahmadi, Arezou
    et al.
    Chalmers University of Technology, Gothenburg, Sweden.
    Figueira, João
    Umeå University.
    Chloride binding in slag containing composite cements2023In: International RILEM conference on synergising expertise towards sustainability and robustness of cement-based materials and concrete structures: SynerCrete’23 - volume 1 / [ed] Agnieszka Jędrzejewska; Fragkoulis Kanavaris; Miguel Azenha; Farid Benboudjema; Dirk Schlicke, Cham: Springer, 2023, 1, , p. 13p. 645-657Chapter in book (Refereed)
    Abstract [en]

    Higher availability of grand granulated blast furnace slag compared to coal fly ash has attributed lots of attention to this supplementary cementitious material in recent years, especially with respect to applications in infrastructure. Therefore, further research on long term performance of slag containing binders in chloride containing environments is promoted. In this article chloride binding in a high slag containing composite binder (70% substitution) with respect to the changes in structure of CSH gel prior and after exposure to chlorides and its effect on chemical and physical chloride binding is accounted for. The changes in the structure of CSH are accounted by NMR analysis and the effect of these changes on chloride binding is addressed through adsorption tests. The results are compared with a ternary binder of cement-silica fume-metakaolin, given the relatively similar chemical composition between these two composite binders, as well as a reference Portland cement binder. The results infer that the slag containing binder exhibits higher chloride binding capacity compared to the metakaolin-silica fume containing. Moreover, a higher share of chemically bound chloride (meaning a lower physical binding) in SCM containing binders is foreseen compared to pure Portland cement system, due to the increased C(-A)-S-H chain length and Al/Si molar ratio in these binders. Furthermore, it is shown that exposure to NaCl causes a higher share of chemically bound chlorides compared to the CaCl2 exposure while the total bound chloride content increases upon exposure to CaCl2.

  • 3.
    Babaahmadi, Arezou
    et al.
    Chalmers University of Technology, Department of Architecture and Civil Engineering, Gotenburg, Sweden.
    Machner, Alisa
    Technical University of Munich, TUM School of Engineering and Design, Department of Materials Engineering, Professorship for Mineral Construction Materials, Munich, Germany.
    Kunther, Wolfgang
    Technical University of Denmark, Department of Environmental and Resource Engineering, Kongens Lyngby, Denmark.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hemstad, Petter
    Norwegian University of Science and Technology, NTNU, Department of Structural Engineering, Trondheim, Norway.
    De Weerdt, Klaartje
    Norwegian University of Science and Technology, NTNU, Department of Structural Engineering, Trondheim, Norway.
    Chloride binding in Portland composite cements containing metakaolin and silica fume2022In: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 161, article id 106924Article in journal (Refereed)
    Abstract [en]

    This paper investigates how the composition of Portland composite cements affects their chloride-binding properties. Hydrated cement pastes prepared with a reference Portland cement and composite Portland cements containing metakaolin and/or silica fume were exposed to NaCl or CaCl2 solutions. Chloride-binding isotherms were determined and the hydrate assemblage was investigated using TGA, XRD, 27Al NMR, 29Si NMR and thermodynamic modelling. Compared to the reference Portland cement paste, silica fume replacement did not alter the chloride-binding capacity. The metakaolin replacement resulted in the highest chloride-binding capacity. When combining silica fume with metakaolin, the chloride binding is similar to the reference Portland cement. In this study the differences in chloride binding were linked not only to changes in the AFm content, but also to alterations in the Al-uptake and chain length of the C(-A)-S-H.

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  • 4.
    Bratthäll, Tove
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Nording, Malin L.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Influence of divalent cations on the extraction of organic acids in coffee determined by GC-MS and NMR2024In: Heliyon, E-ISSN 2405-8440, Vol. 10, no 5, article id e26625Article in journal (Refereed)
    Abstract [en]

    The perceived flavor of coffee varies depending on the composition of the brewing water, and the influencing mechanisms are poorly understood. To investigate the effect of dissolved divalent cations on the extraction of organic acids in coffee, magnesium and calcium chloride salts were added pre- and post-brew. Citric, malic, lactic and quinic acid were analyzed using gas chromatography – mass spectrometry and nuclear magnetic resonance techniques. At concentrations typically found in drinking water, the salts resulted in limited variation of the acid content, while ten-fold higher salt concentrations produced more pronounced variations. Comparisons between pre- and post-brew additions showed similar acid content in most cases, suggesting that extraction of acids proceeds independent of the water composition. Interactions taking place post-brew may, however, influence the perceived flavor. A scientific basis for water quality recommendations in the coffee industry is long overdue and this work provides experimental and analytical contributions to continued research.

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  • 5.
    Figueira, Joao
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Adolfsson, Rolf
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Nordin Adolfsson, Annelie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences, Diagnostic Radiology. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Öhman, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Serum Metabolite Markers of Dementia Through Quantitative NMR Analysis: The Importance of Threonine-Linked Metabolic Pathways2019In: Journal of Alzheimer's Disease, ISSN 1387-2877, E-ISSN 1875-8908, Vol. 69, no 3, p. 763-774Article in journal (Refereed)
    Abstract [en]

    There is a great need for diagnostic biomarkers of impending dementia. Metabolite markers in blood have been investigated in several studies, but inconclusive findings encourage further investigation, particularly in the pre-diagnostic phase. In the present study, the serum metabolomes of 110 dementia or pre-diagnostic dementia individuals and 201 healthy individuals matched for age, gender, and education were analyzed by nuclear magnetic resonance spectroscopy in combination with multivariate data analysis. 58 metabolites were quantified in each of the 311 samples. Individuals with dementia were discriminated from controls using a panel of seven metabolites, while the pre-diagnostic dementia subjects were distinguished from controls using a separate set of seven metabolites, where threonine was a common significant metabolite in both panels. Metabolite and pathway alterations specific for dementia and pre-diagnostic dementia were identified, in particular a disturbed threonine catabolism at the pre-diagnostic stage that extends to several threonine-linked pathways at the dementia stage.

  • 6.
    Figueira, Joao
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Jonsson, Pär
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Nordin Adolfsson, Annelie
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Adolfsson, Rolf
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Psychiatry.
    Nyberg, Lars
    Umeå University, Faculty of Medicine, Department of Radiation Sciences. Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB).
    Öhman, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    NMR analysis of the human saliva metabolome distinguishes dementia patients from matched controls2016In: Molecular Biosystems, ISSN 1742-206X, E-ISSN 1742-2051, Vol. 12, no 8, p. 2562-2571Article in journal (Refereed)
    Abstract [en]

    Saliva is a biofluid that is sensitive to metabolic changes and is straightforward to collect in a non-invasive manner, but it is seldom used for metabolite analysis when studying neurodegenerative disorders. We present a procedure for both an untargeted and targeted analysis of the saliva metabolome in which nuclear magnetic resonance (NMR) spectroscopy is used in combination with multivariate data analysis. The applicability of this approach is demonstrated on saliva samples selected from the 25 year prospective Betula study, including samples from dementia subjects with either Alzheimer's disease (AD) or vascular dementia at the time of sampling or who developed it by the next sampling/assessment occasion five years later, and age-, gender-, and education-matched control individuals without dementia. Statistically significant multivariate models were obtained that separated patients with dementia from controls and revealed seven discriminatory metabolites. Dementia patients showed significantly increased concentrations of acetic acid (fold change (fc) = 1.25, p = 2 x 10(-5)), histamine (fc = 1.26, p = 0.019), and propionate (fc = 1.35, p = 0.002), while significantly decreased levels were observed for dimethyl sulfone (fc = 0.81, p = 0.005), glycerol (fc = 0.79, p = 0.04), taurine (fc = 0.70, p = 0.007), and succinate (fc = 0.62, p = 0.008). Histamine, succinate, and taurine are known to be important in AD, and acetic acid and glycerol are involved in related pathways. Dimethyl sulfone and propionate originate from the diet and bacterial flora and might reflect poorer periodontal status in the dementia patients. For these seven metabolites, a weak but statistically significant pre-diagnostic value was observed. Taken together, we present a robust and general NMR analysis approach for studying the saliva metabolome that has potential use for screening and early detection of dementia.

  • 7.
    Figueira, João
    et al.
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Gouveia-Figueira, Sandra
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Öhman, Carina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lif Holgerson, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Nording, Malin L
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Öhman, Anders
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Metabolite quantification by NMR and LC-MS/MS reveals differences between unstimulated, stimulated, and pure parotid saliva2017In: Journal of Pharmaceutical and Biomedical Analysis, ISSN 0731-7085, E-ISSN 1873-264X, Vol. 140, p. 295-300Article in journal (Refereed)
    Abstract [en]

    Saliva is a readily available biofluid that is sensitive to metabolic changes and can be collected through rapid and non-invasive collection procedures, and it shows great promise for clinical metabolomic studies. This work studied the metabolite composition of, and the differences between, saliva samples collected by unstimulated spitting/drooling, paraffin chewing-stimulated spitting, and parotid gland suction using targeted nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for metabolite quantification. As applied here, these two analytical techniques provide complementary metabolite information and together extend the metabolome coverage with robust NMR quantification of soluble metabolites and sensitive targeted LC-MS/MS analysis of bioactive lipids in specific metabolic pathways. The NMR analysis was performed on ultrafiltrated (3kDa cutoff) saliva samples and resulted in a total of 45 quantified metabolites. The LC-MS/MS analysis was performed on both filtered and unfiltered samples and resulted in the quantification of two endocannabinoids (AEA and PEA) and 22 oxylipins, which at present is the most comprehensive targeted analysis of bioactive lipids in human saliva. Important differences in the metabolite composition were observed between the three saliva sample collection methods, which should be taken into consideration when designing metabolomic studies of saliva. Furthermore, the combined use of the two metabolomics platforms (NMR and LC-MS/MS) proved to be viable for research and clinical studies of the salivary metabolome.

  • 8. Gouveia, Marisol
    et al.
    Figueira, João
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jardim, Manuel G.
    Castro, Rita
    Tomas, Helena
    Rissanen, Kari
    Rodrigues, Joao
    Poly(alkylidenimine) Dendrimers Functionalized with the Organometallic Moiety [Ru(η5-C5H5)(PPh3)2]+ as Promising Drugs Against Cisplatin-Resistant Cancer Cells and Human Mesenchymal Stem Cells2018In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 23, no 6, article id 1471Article in journal (Refereed)
    Abstract [en]

    Here and for the first time, we show that the organometallic compound [Ru(η5-C5H5)(PPh3)2Cl] (RuCp) has potential to be used as a metallodrug in anticancer therapy, and further present a new approach for the cellular delivery of the[Ru(η5-C5H5)(PPh3)2]+ fragment via coordination on the periphery of low-generation poly(alkylidenimine) dendrimers through nitrile terminal groups. Importantly, both the RuCp and the dendrimers functionalized with [Ru(η5-C5H5)(PPh3)2]+ fragments present remarkable toxicity towards a wide set of cancer cells (Caco-2, MCF-7, CAL-72, and A2780 cells), including cisplatin-resistant human ovarian carcinoma cell lines (A2780cisR cells). Also, RuCp and the prepared metallodendrimers are active against human mesenchymal stem cells (hMSCs), which are often found in the tumor microenvironment where they seem to play a role in tumor progression and drug resistance.

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  • 9.
    Latham, Kenneth G.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Discipline of Chemistry, University of Newcastle, NSW, Callaghan, Australia.
    Kozyatnyk, Ivan
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Rosenbaum, Erik
    MTC-Miljötekniskt Center AB, Dåva Energiväg 8, Umeå, Sweden.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Self-generation of low ash carbon microspheres from the hydrothermal supernatant of anaerobic digestate: Formation insights and supercapacitor performance2021In: Chemical Engineering Journal Advances, E-ISSN 2666-8211, Vol. 6, article id 100097Article in journal (Refereed)
    Abstract [en]

    This work provides the first observations of and insights into the self-generation of carbon microspheres from the supernatant after hydrothermal carbonization of anaerobic digestate has been completed and the hydrochar removed. Solid State NMR and XPS revealed that the carbon microspheres were comprised of decomposed fragments of proteins, carbohydrates and lignin. The carbon microspheres were significantly lower in ash content (3.1%), compared to the hydrothermal solid (41.2%) and precursor (25.2%) and their formation reduced the total organic carbon load of the supernatant. The low ash content allowed them to be easily activated, achieving a surface area of 1711.0 m2 g−1, compared to 51.4 m2 g−1 for the activated hydrothermal solid and 12.8 m2 g−1 for the activated precursor. The microcarbon spheres achieved a specific capacitance from cyclic voltammetry of 86 F g−1 at 100 mV s−1 to 176 F g−1 at 1 mV s−1, while the gravimetric capacitance was 42 F g−1 at 25 A g−1 and 140 F g−1 at 0.5 A g−1 in 0.5 M Li2SO4 and a 1.8V potential window. Overall, this study highlights the importance of exploring this new product and its valorisation potential for the hydrothermal carbonization of ash-rich precursors.

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  • 10.
    Latham, Kenneth G.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Discipline of Chemistry, University of Newcastle, NSW, Callaghan, Australia.
    Matsakas, Leonidas
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Kozyatnyk, Ivan
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Occupational and Environmental Medicine Center, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
    Rova, Ulrika
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Christakopoulos, Paul
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Impact of temperature and residence time on the hydrothermal carbonization of organosolv lignin2022In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 166, article id 105623Article in journal (Refereed)
    Abstract [en]

    Herein, we have investigated how pure lignin extracted from birch and spruce via a hybrid organosolv/steam explosion method reacts under hydrothermal carbonization (HTC) to produce hydrochar, a product that has found applications in environmental remediation, energy storage and catalysis. We subjected thirteen lignin samples obtained from birch and spruce under different extraction conditions to HTC at 260 ℃ for four hours. The yield of hydrochar varied between the different extraction conditions and source, although no clear correlation between extraction conditions and yield could be observed. For instance, lignin from birch pretreated in 60%v/v ethanol for 15 min resulted in a hydrochar yield of 39 wt%. Increasing the time to 30 and 60 resulted in a hydrochar yield of 27 wt% and 23 wt%, respectively. This suggested that small changes in the organosolv reaction conditions might produce highly structurally different lignin, resulting in the difference in HTC yield. Thus, we chose a subset of four lignin samples to investigate in-depth, subjecting these samples to a range of hydrothermal reaction temperatures and residence times. Solid State NMR and FTIR analysis indicated that the most significant structural changes occurred below 230 ℃ resulting in the breaking of C-O- linkages. Increasing the temperature or time had minimal impact, with no further C-O- linkages broken and no changes to the ring structure of C-C groups. Size exclusion chromatography indicated that the degree of micro and macromolecules in the liquid product varied significantly with lignin source and HTC reaction conditions. Overall, this study demonstrated that lignin has a large reaction range where it produces a very chemically similar solid product, with the only major difference being the yield of material. This is important for industry, as it indicates that a similar solid product can be easily achieved independently of extraction conditions allowing the HTC reaction to be tuned towards extracting the maximum benefit from products contained in the liquid.

  • 11.
    Latham, Kenneth G.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Discipline of Chemistry, University of Newcastle, Callaghan, NSW, Australia.
    Matsakas, Leonidas
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Figueira, João
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Rova, Ulrika
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Christakopoulos, Paul
    Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, Luleå, Sweden.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Examination of how variations in lignin properties from Kraft and organosolv extraction influence the physicochemical characteristics of hydrothermal carbon2021In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 155, article id 105095Article in journal (Refereed)
    Abstract [en]

    Seven different lignin samples, three from Kraft extraction and four from organosolv extraction, were subjected to hydrothermal treatment at 260℃ for four hours to assess the impact of lignin type on the physicochemical properties of the hydrothermal material. The 13C Solid state NMR, XPS, FTIR and SEM analysis revealed that the different sources of lignin and the extraction conditions created variations in the degree of syringyl and guaiacyl subunits, inter-unit bonding arrangements, morphology and surface composition. Hydrothermal carbonization appeared to “normalize” the differences between each of the lignin samples, via breaking β-O-4 or α-O-4 linkages, removal of methoxy and syringyl subunits, and creation of C–C and 4-O-5 linkages to polymerization into large 100−200 μm amorphous carbon particles. Overall, this study indicates that the source and extraction type have minimal influence on the physicochemical structure and morphology of the final hydrothermal product.

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  • 12.
    Ripszam, Matyas
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Paczkowska, Joanna
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Figueira, João
    Umeå University, Faculty of Medicine, Department of Pharmacology and Clinical Neuroscience, Clinical Neuroscience.
    Veenaas, Cathrin
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Dissolved organic carbon quality and sorption of organic pollutants in the Baltic Sea in light of future climate change2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 3, p. 1445-1452Article in journal (Refereed)
    Abstract [en]

    Regional climate change scenarios predict increased temperature and precipitation in the northern Baltic Sea, leading to a greater runoff of fresh water and terrestrial dissolved organic carbon (DOC) within the second part of the 21st century. As a result, the current north to south gradient in temperature and salinity is likely to be shifted further toward the south. To examine if such climate change effects would cause alterations in the environmental fate of organic pollutants, spatial variations of DOC quality and sorption behavior toward organic contaminants were examined using multiple analytical methods. The results showed declining contents of aromatic functional groups in DOC along a north to south gradient. Similarly, the sorption of a diverse set of organic contaminants to DOC also showed spatial differences. The sorption behavior of these contaminants was modeled using poly parameter linear energy relationships. The resulting molecular descriptors indicated clear differences in the sorption properties of DOC sampled in northern and southern parts of the Baltic Sea, which imply that more organic contaminants are sorbed to DOC in the northern part. The extent of this sorption process determines whether individual contaminants will partition to biota via direct uptake or through sorption to DOC, which serves as food source for bacteria-based food-webs.

  • 13. Salehi, Alireza M.
    et al.
    Nilsson, Ida A. K.
    Figueira, João
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Thornton, Laura M.
    Abdulkarim, Israa
    Pålsson, Erik
    Bulik, Cynthia M.
    Landén, Mikael
    Serum profiling of anorexia nervosa: A 1H NMR-based metabolomics study2021In: European Neuropsychopharmacology, ISSN 0924-977X, E-ISSN 1873-7862, Vol. 49, p. 1-10Article in journal (Refereed)
    Abstract [en]

    Our understanding of pathophysiological mechanisms underlying anorexia nervosa (AN) is incomplete. The aim was to conduct a metabolomics profiling of serum samples from women with AN (n = 65), women who have recovered from AN (AN-REC, n = 65), and age-matched healthy female controls (HC, n = 65). Serum concentrations of 21 metabolites were measured using proton nuclear magnetic resonance (1H NMR). We used orthogonal partial least-squares discriminant analysis (OPLS-DA) modeling to assign group classification based on the metabolites. Analysis of variance (ANOVA) was used to test for metabolite concentration differences across groups. The OPLS-DA model could distinguish between the AN and HC groups (p = 9.05 × 10–11 R2Y = 0.36, Q2 = 0.37) and between the AN-REC and HC groups (p = 8.47 × 10–6, R2Y = 0.36, Q2 = 0.24,), but not between the AN and AN-REC groups (p = 0.63). Lower methanol concentration in the AN and AN-REC group explained most of the variance. Likewise, the strongest finding in the univariate analyses was lower serum methanol concentration in both AN and AN-REC compared with HC, which withstood adjustment for body mass index (BMI). We report for the first time lower serum concentrations of methanol in AN. The fact that low methanol was also found in recovered AN suggests that low serum concentration of methanol could either be trait marker or a scar effect of AN.

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  • 14.
    Serk, Henrik
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Nilsson, Mats B.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Krüger, Jan Paul
    UDATA GmbH - Umwelt und Bildung, Neustadt an der Weinstraße, Germany; Departement Umweltgeowissenschaften, Universität Basel, Basel, Switzerland.
    Leifeld, Jens
    Departement Umweltgeowissenschaften, Universität Basel, Basel, Switzerland; Agroscope, Climate and Agriculture Group, Zurich, Switzerland.
    Alewell, Christine
    Departement Umweltgeowissenschaften, Universität Basel, Basel, Switzerland.
    Schleucher, Jürgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Organochemical characterization of peat reveals decomposition of specific hemicellulose structures as the main cause of organic matter loss in the acrotelm2022In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 56, no 23, p. 17410-17419Article in journal (Refereed)
    Abstract [en]

    Peatlands store carbon in the form of dead organic residues. Climate change and human impact impose risks on the sustainability of the peatlands carbon balance due to increased peat decomposition. Here, we investigated molecular changes in the upper peat layers (0-40 cm), inferred from high-resolution vertical depth profiles, from a boreal peatland using two-dimensional 1H-13C nuclear magnetic resonance (NMR) spectroscopy, and comparison to δ13C, δ15N, and carbon and nitrogen content. Effects of hydrological conditions were investigated at respective sites: natural moist, drainage ditch, and natural dry. The molecular characterization revealed preferential degradation of specific side-chain linkages of xylan-type hemicelluloses within 0-14 cm at all sites, indicating organic matter losses up to 25%. In contrast, the xylan backbone, galactomannan-type hemicelluloses, and cellulose were more resistant to degradation and accumulated at the natural moist and drainage site. δ13C, δ15N, and carbon and nitrogen content did not correlate with specific hemicellulose structures but reflected changes in total carbohydrates. Our analysis provides novel insights into peat carbohydrate decomposition and indicates substantial organic matter losses in the acrotelm due to the degradation of specific hemicellulose structures. This suggests that variations in hemicellulose content and structure influence peat stability, which may have important implications with respect to climate change.

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  • 15.
    Serk, Henrik
    et al.
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics. Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Nilsson, Mats B.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wieloch, Thomas
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    Schleucher, Jürgen
    Umeå University, Faculty of Medicine, Department of Medical Biochemistry and Biophysics.
    CO2 fertilization of Sphagnum peat mosses is modulated by water table level and other environmental factors2021In: Plant, Cell and Environment, ISSN 0140-7791, E-ISSN 1365-3040, Vol. 44, no 6, p. 1756-1768Article in journal (Refereed)
    Abstract [en]

    Sphagnum mosses account for most accumulated dead organic matter in peatlands. Therefore, understanding their responses to increasing atmospheric CO2 is needed for estimating peatland C balances under climate change. A key process is photorespiration: a major determinant of net photosynthetic C assimilation that depends on the CO2 to O2 ratio. We used climate chambers to investigate photorespiratory responses of Sphagnum fuscum hummocks to recent increases in atmospheric CO2 (from 280 to 400 ppm) under different water table, temperature, and light intensity levels. We tested the photorespiratory variability using a novel method based on deuterium isotopomers (D6S/D6R ratio) of photosynthetic glucose. The effect of elevated CO2 on photorespiration was highly dependent on water table. At low water table (−20 cm), elevated CO2 suppressed photorespiration relative to C assimilation, thus substantially increasing the net primary production potential. In contrast, a high water table (~0 cm) favored photorespiration and abolished this CO2 effect. The response was further tested for Sphagnum majus lawns at typical water table levels (~0 and −7 cm), revealing no effect of CO2 under those conditions. Our results indicate that hummocks, which typically experience low water table levels, benefit from the 20th century's increase in atmospheric CO2.

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  • 16.
    Shi, Andong
    et al.
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Nunan, Naoise
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden; Institute of Ecology and Environmental Sciences, Sorbonne Université, Paris, France.
    Figueira, Joao
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Herrmann, Anke M.
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Wetterlind, Johanna
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Skara, Sweden.
    Long-term ley and manure managements have consistent effects on microbial functional profiles and organic C groups across soils from a latitudinal gradient2022In: Agronomy for Sustainable Development, ISSN 1774-0746, E-ISSN 1773-0155, Vol. 42, no 6, article id 107Article in journal (Refereed)
    Abstract [en]

    Soil organic matter (SOM) is important in maintaining soil fertility and other ecosystem functions. Yet, land management in intensive agriculture has caused SOM level to decrease, with knock-on effects for soil fertility and quality. Therefore, land management options that ensure that SOM is not depleted and that soil functions are better sustained are of increasing interest. However, there is limited knowledge on how different land managements affect the composition of SOM and associated microbial functional profiles. Twelve long-term field experiments, covering a wide range of climatic zones and soil types, were selected in Sweden. They focused on the role of combining ley in crop rotations with the manure application (livestock farm), as opposed to the management without ley and receiving only inorganic fertilizer (arable farm). In ten out of the 12 study sites, livestock farm management tended to have higher proportions of aliphatic and double bonded C groups, as estimated by mid-infrared spectroscopy. This was further confirmed by 13C NMR analysis, which found greater proportions of O-alkyl and di-O-alkyl groups and less aromatic C in livestock farm than arable farm management in five of the eight sites analyzed. The changes in SOM composition were reflected in microbial functional profiles across many sites: soils from livestock farm management utilized more carbohydrates and amino acids, while polymer and aromatic compounds were associated with arable farm management. Overall, shifts in both microbial functional profiles and SOM composition showed great consistency across geographical and climatic zones. Livestock farm management maintained higher levels of microbial functional diversity and were associated with higher proportions of “reactive” C functional groups. Our investigation demonstrates that livestock farm management could maintain soil fertility over the long-term via the changes in SOM composition and the regulation of microbial functional profiles.

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