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  • 1.
    Albinsson, Ola
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Lundevall, Åsa
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Sehati, Parisa
    Linköpings universitet.
    Stålhanske, Christina
    RISE.
    Sundberg, P
    Mattsson, Lards-Göran
    KTH Royal Institute of Technology .
    Sjövall, Peter
    Rise.
    The influence of surface composition and plasma treatment on adhesion2015In: Proceedings of GPD Glass Performance Days 2015, 2015, p. 11-14Conference paper (Other academic)
  • 2. Almstrand, A-C
    et al.
    Ljungström, E
    Lausmaa, J
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Bake, B
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Olin, A-C
    Airway Monitoring by Collection and Mass Specrometric Analysis of Exhaled Particles2009In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 81, no 2, p. 662-668Article in journal (Refereed)
    Abstract [en]

    We describe a new method for simultaneously collecting particles in exhaled air for subsequent chemical analysis and measuring their size distribution. After forced exhalation, particles were counted and collected in spots on silicon wafers with a cascade impactor. Several phospholipids were identified by time-of-flight secondary ion mass spectrometric analysis of the collected spots, suggesting that the particles originated from the lower airways. The amount of particles collected in ten exhalations was sufficient for characterizing the phospholipid composition. The feasibility of the technique in respiratory research is demonstrated by analysis of the phospholipid composition of exhaled particles from healthy controls, patients with asthma, and patients with cystic fibrosis. We believe this technology will be useful for monitoring patients with respiratory disease and has a high potential to detect new biomarkers in exhaled air.

  • 3.
    Carlred, Louise
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik. Chalmers University of Technology, Sweden.
    Michno, Wojciech
    University of Gothenburg, Sweden.
    Kaya, Ibrahim
    University of Gothenburg, Sweden.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik. Chalmers University of Technology, Sweden.
    Syvänen, Stina
    Uppsala University, Sweden.
    Hanrieder, Jörg
    University of Gothenburg, Sweden; Chalmers University of Technology, Sweden; University College London, UK.
    Probing amyloid-β pathology in transgenic Alzheimer's disease (tgArcSwe) mice using MALDI imaging mass spectrometry2016In: Journal of Neurochemistry, ISSN 0022-3042, E-ISSN 1471-4159, Vol. 138, no 3, p. 469-478Article in journal (Refereed)
    Abstract [en]

    The pathological mechanisms underlying Alzheimer's disease (AD) are still not understood. The disease pathology is characterized by the accumulation and aggregation of amyloid-β (Aβ) peptides into extracellular plaques, however the factors that promote neurotoxic Aβ aggregation remain elusive. Imaging mass spectrometry (IMS) is a powerful technique to comprehensively elucidate the spatial distribution patterns of lipids, peptides and proteins in biological tissues. In the present study, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS)-based imaging was used to study Aβ deposition in transgenic mouse brain tissue and to elucidate the plaque-associated chemical microenvironment. The imaging experiments were performed in brain sections of transgenic Alzheimer's disease mice carrying the Arctic and Swedish mutation of amyloid-beta precursor protein (tgArcSwe). Multivariate image analysis was used to interrogate the IMS data for identifying pathologically relevant, anatomical features based on their chemical identity. This include cortical and hippocampal Aβ deposits, whose amyloid peptide content was further verified using immunohistochemistry and laser microdissection followed by MALDI MS analysis. Subsequent statistical analysis on spectral data of regions of interest revealed brain region-specific differences in Aβ peptide aggregation. Moreover, other plaque-associated protein species were identified including macrophage migration inhibitory factor suggesting neuroinflammatory processes and glial cell reactivity to be involved in AD pathology. The presented data further highlight the potential of IMS as a powerful approach in neuropathology. Hanrieder et al. described an imaging mass spectrometry based study on comprehensive spatial profiling of C-terminally truncated Aβ species within individual plaques in tgArcSwe mice. Here, brain region-dependent differences in Aβ truncation and other plaque-associated proteins, such as macrophage migration inhibitory factor, were observed. The data shed further light on plaque-associated molecular mechanisms implicated in Alzheimer's pathogenesis.

  • 4.
    Carlred, Louise
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Simultaneous imaging of amyloid-β and lipids in brain tissue using antibody-coupled liposomes and time-of-flight secondary ion mass spectrometry2014In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, no 28, p. 9973-9981Article in journal (Refereed)
    Abstract [en]

    The spatial localization of amyloid-β peptide deposits, the major component of senile plaques in Alzheimer's disease (AD), was mapped in transgenic AD mouse brains using time-of-flight secondary ion mass spectrometry (ToF-SIMS), simultaneously with several endogenous molecules that cannot be mapped using conventional immunohistochemistry imaging, including phospholipids, cholesterol and sulfatides. Whereas the endogenous lipids were detected directly, the amyloid-β deposits, which cannot be detected as intact entities with ToF-SIMS because of extensive ion-induced fragmentation, were identified by specific binding of deuterated liposomes to antibodies directed against amyloid-β. Comparative investigation of the amyloid-β deposits using conventional immunohistochemistry and fluorescence microscopy suggests similar sensitivity but a more surface-confined identification due to the shallow penetration depth of the ToF-SIMS signal. The recorded ToF-SIMS images thus display the localization of lipids and amyloid-β in a narrow (∼10 nm) two-dimensional plane at the tissue surface. As compared to a frozen nontreated tissue sample, the liposome preparation protocol generally increased the signal intensity of endogenous lipids, likely caused by matrix effects associated with the removal of salts, but no severe effects on the tissue integrity and the spatial distribution of lipids were observed with ToF-SIMS or scanning electron microscopy (SEM). This method may provide an important extension to conventional tissue imaging techniques to investigate the complex interplay of different kinds of molecules in neurodegenerative diseases, in the same specimen. However, limitations in target accessibility of the liposomes as well as unspecific binding need further consideration.

  • 5.
    Carlred, Louise
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik. Chalmers University of Technology, Sweden.
    Vukojević, Vladana
    Karolinska Institute, Sweden.
    Johansson, Björn
    Karolinska Institute, Sweden.
    Schalling, Martin
    Karolinska Institute, Sweden.
    Höök, Fredrik
    Chalmers University of Technology, Sweden.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik. Chalmers University of Technology, Sweden.
    Imaging of amyloid-β in alzheimer’s disease transgenic mouse brains with ToF-SIMS using immunoliposomes2016In: Biointerphases, ISSN 1934-8630, E-ISSN 1559-4106, Vol. 11, no 2, p. 1-11, article id 02A312Article in journal (Refereed)
    Abstract [en]

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been proven to successfully image different kinds of molecules, especially a variety of lipids, in biological samples. Proteins, however, are difficult to detect as specific entities with this method due to extensive fragmentation. To circumvent this issue, the authors present in this work a method developed for detection of proteins using antibody-conjugated liposomes, so called immunoliposomes, which are able to bind to the specific protein of interest. In combination with the capability of ToF-SIMS to detect native lipids in tissue samples, this method opens up the opportunity to analyze many different biomolecules, both lipids and proteins, at the same time, with high spatial resolution. The method has been applied to detect and image the distribution of amyloid-β (Aβ), a biologically relevant peptide in Alzheimer’s disease (AD), in transgenic mouse brain tissue. To ensure specific binding, the immunoliposome binding was verified on a model surface using quartz crystal microbalance with dissipation monitoring. The immunoliposome binding was also investigated on tissue sections with fluorescence microscopy, and compared with conventional immunohistochemistry using primary and secondary antibodies, demonstrating specific binding to Aβ. Using ToF-SIMS imaging, several endogenous lipids, such as cholesterol and sulfatides, were also detected in parallel with the immunoliposome-labeled Aβ deposits, which is an advantage compared to fluorescence microscopy. This method can thus potentially provide further information about lipid–protein interactions, which is important to understand the mechanisms of neurodegeneration in AD.

  • 6. Carlsson, Lennart
    et al.
    Lausmaa, Jukka
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    A cell preparation method allowing subcellular localization of cholesterol and phosphocholine with imaging ToF-SIMS2003In: Colloids and Surfaces B: Biointerface, Vol. 30, no 30, p. 87-92Article in journal (Refereed)
    Abstract [en]

    A cell preparation method allowing subcellular localization of cholesterol and phosphocholine with imaging ToF-SIMS

  • 7.
    Colombo, Stefan
    et al.
    Uppsala University, Sweden.
    Brisander, Magnus
    XSpray Microparticles AB, Sweden.
    Haglöf, Jakob
    Uppsala University, Sweden.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Andersson, Per
    XSpray Microparticles AB, Sweden.
    Østergaard, Jesper
    University of Copenhagen, Denmark.
    Malmsten, Martin
    Uppsala University, Sweden.
    Matrix effects in nilotinib formulations with pH-responsive polymer produced by carbon dioxide-mediated precipitation2015In: International Journal of Pharmaceutics, ISSN 0378-5173, E-ISSN 1873-3476, Vol. 494, no 1, p. 205-217, article id 15114Article in journal (Refereed)
    Abstract [en]

    Factors determining the pH-controlled dissolution kinetics of nilotinib formulations with the pH-titrable polymer hydroxypropyl methylcellulose phthalate, obtained by carbon dioxide-mediated precipitation, were mechanistically examined in acid and neutral environment. The matrix effect, modulating the drug dissolution, was characterized with a battery of physicochemical methodologies, including ToF-SIMS for surface composition, SAXS/WAXS and modulated DSC for crystallization characterization, and simultaneous UV-imaging and Raman spectroscopy for monitoring the dissolution process in detail. The hybrid particle formulations investigated consisted of amorphous nilotinib embedded in a polymer matrix in single continuous phase, displaying extended retained amorphicity also under wet conditions. It was demonstrated by Raman and FTIR spectroscopy that the efficient drug dispersion and amorphization in the polymer matrix were mediated by hydrogen bonding between the drug and the phthalate groups on the polymer. Simultaneous Raman and UV-imaging studies of the effect of drug load on the swelling and dissolution of the polymer matrix revealed that high nilotinib load prevented matrix swelling on passage from acid to neutral pH, thereby preventing re-precipitation and re-crystallization of incorporated nilotinib. These findings provide a mechanistic foundation of formulation development of nilotinib and other protein kinase inhibitors, which are now witnessing an intense therapeutic and industrial attention due to the difficulty in formulating these compounds so that efficient oral bioavailability is reached.

  • 8.
    Drake, Henrik
    et al.
    Linnaeus University, Sweden.
    Aström, Mats E.
    Linnaeus University, Sweden.
    Heim, Christine
    Georg-August University, Germany.
    Broman, Curt
    Stockholm University, Sweden.
    Aström, Jan
    CSC-IT Center for Science, Finland.
    Whitehouse, Martin
    Swedish Museum of Natural History, Sweden.
    Ivarsson, Magnus
    Swedish Museum of Natural History, Sweden.
    Siljeström, Sandra
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Extreme 13 C depletion of carbonates formed during oxidation of biogenic methane in fractured granite2015In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 6, article id 7020Article in journal (Refereed)
    Abstract [en]

    Precipitation of exceptionally 13C-depleted authigenic carbonate is a result of, and thus a tracer for, sulphate-dependent anaerobic methane oxidation, particularly in marine sediments. Although these carbonates typically are less depleted in 13C than in the source methane, because of incorporation of C also from other sources, they are far more depleted in 13C (δ13C as light as -69% V-PDB) than in carbonates formed where no methane is involved. Here we show that oxidation of biogenic methane in carbon-poor deep groundwater in fractured granitoid rocks has resulted in fracture-wall precipitation of the most extremely 13Cdepleted carbonates ever reported, δ13C down to -125% V-PDB. A microbial consortium of sulphate reducers and methane oxidizers has been involved, as revealed by biomarker signatures in the carbonates and S-isotope compositions of co-genetic sulphide. Methane formed at shallow depths has been oxidized at several hundred metres depth at the transition to a deep-seated sulphate-rich saline water. This process is so far an unrecognized terrestrial sink of methane.

  • 9.
    Gren, Johan A.
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Eriksson, Mats E.
    Lund University, Sweden.
    Sylvestersen, Rene L.
    MUSERUM, Denmark.
    Marone, Frederica
    Paul Scherrer Institute, Switzerland.
    Sigfridsson Clauss, Kajsa G. V.
    MAX IV Laboratory, Sweden.
    Taylor, Gavin J.
    Lund University, Sweden.
    Carlson, Stefan
    MAX IV Laboratory, Sweden.
    Uvdal, Per
    Lund University, Sweden.
    Lindgren, Johan
    Lund University, Sweden.
    Molecular and microstructural inventory of an isolated fossil bird feather from the Eocene Fur Formation of Denmark2017In: Palaeontology, ISSN 0031-0239, E-ISSN 1475-4983, Vol. 60, no 1, p. 73-90Article in journal (Refereed)
    Abstract [en]

    An isolated, yet virtually intact contour feather (FUM-1980) from the lower Eocene Fur Formation of Denmark was analysed using multiple imaging and molecular techniques, including field emission gun scanning electron microscopy (FEG-SEM), X-ray absorption spectroscopy and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Additionally, synchrotron radiation X-ray tomographic microscopy (SRXTM) was employed in order to produce a digital reconstruction of the fossil. Under FEG-SEM, the proximal, plumulaceous part of the feather revealed masses of ovoid microstructures, about 1.7 μm long and 0.5 μm wide. Microbodies in the distal, pennaceous portion were substantially smaller (averaging 0.9 × 0.2 μm), highly elongate, and more densely packed. Generally, the microbodies in both the plumulaceous and pennaceous segments were aligned along the barbs and located within shallow depressions on the exposed surfaces. Biomarkers consistent with animal eumelanins were co-localized with the microstructures, to suggest that they represent remnant eumelanosomes (i.e. eumelanin-housing cellular organelles). Additionally, ToF-SIMS analysis revealed the presence of sulfur-containing organics – potentially indicative of pheomelanins – associated with eumelanin-like compounds. However, since there was no correlation between melanosome morphology and sulfur content, we conclude these molecular structures derive from diagenetically incorporated sulfur rather than pheomelanin. Melanosomes corresponding roughly in both size and morphology with those in the proximal part of FUM-1980 are known from contour feathers of extant parrots (Psittaciformes), an avian clade that has previously been reported from the Fur Formation.

  • 10. Gunnarsson, A
    et al.
    Jonsson, P
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Höök, F
    Probing molecular recognition on the single molecule level2010In: European Cells and Materials, ISSN 1473-2262, E-ISSN 1473-2262, Vol. 20, no S.3, p. 97-Article in journal (Refereed)
  • 11. Gunnarsson, A
    et al.
    Kollmer, F
    Sohn, S
    Höök, F
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Spatial-resolution limits in mass spectrometry imaging of supported lipid bilayers and individual lipid vesicles2010In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 82, no 6, p. 2426-2433Article in journal (Refereed)
    Abstract [en]

    The capabilities of time-of-flight secondary ion mass spectrometry (TOF-SIMS) with regards to limits in lateral resolution for biological samples are examined using supported lipid bilayers and individual lipid vesicles, both being among the most commonly used cell membrane mimics. Using supported 1-palmitoyl-2-oleoyl-sn-glycero3-phosphocholine (POPC) bilayers confined to a SiO2 substrate by a chemically modified gold surface, the edge of the lipid bilayer was analyzed by imaging TOFSIMS to assess the lateral resolution. The results using 80 keV Bi32+ primary ions show that, under optimized conditions, mass spectrometry imaging of specific unlabeled lipid fragments is possible with sub-100 nm lateral resolution. Comparison of the secondary ion yields for the phosphocholine ion (m/z 184) from a POPC bilayer using C60+ or Bi3+ primary ions showed similar results, indicating an advantage of Bi3+ primary ions for high-resolution imaging of lipid membranes, due to their better demonstrated focusing capability. Moreover, using 300 nm vesicles of different lipid composition, the capability to detect and chemically identify individual submicrometer lipid vesicles at separations down to ~ 1 μm is demonstrated.

  • 12.
    Gunnarsson, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Kollmer, Felix
    Sohn, Sascha
    Höök, Fredrik
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    High-resolution mass spectrometry imaging of supported lipid bilayers and individual lipid vesicles2010In: Analytical Chemistry, Vol. 82, p. 2426-2433Article in journal (Refereed)
  • 13.
    Gunnarsson, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Höök, Fredrik
    Liposome-based bio-barcodes for on-chip DNA detection using imaging mass spectrometry2010In: Nano Letters, Vol. 10, p. 732-737Article in journal (Refereed)
  • 14.
    Hannestad, Jonas
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. Chalmers University of Technology, Sweden.
    Höök, Fredrik
    Chalmers University of Technology, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials. Chalmers University of Technology, Sweden.
    Nanometer-scale molecular organization in lipid membranes studied by time-of-flight secondary ion mass spectrometry2018In: Biointerphases, ISSN 1934-8630, E-ISSN 1559-4106, Vol. 13, no 3, article id 03B408Article in journal (Refereed)
    Abstract [en]

    The organization of lipid membranes plays an important role in a wide range of biological processes at different length scales. Herein, the authors present a procedure based on time-of-flight secondary ion mass spectrometry (ToF-SIMS) to characterize the nanometer-scale ordering of lipids in lipid membrane structures on surfaces. While ToF-SIMS is a powerful tool for label-free analysis of lipid-containing samples, its limited spatial resolution prevents in-depth knowledge of how lipid properties affect the molecular assembly of the membrane. The authors overcome this limitation by measuring the formation of lipid dimers, originating in the same nanometer-sized primary ion impact areas. The lipid dimers reflect the local lipid environment and thus allow us to characterize the membrane miscibility on the nanometer level. Using this technique, the authors show that the chemical properties of the constituting lipids are critical for the structure and organization of the membrane on both the nanometer and micrometer length scales. Our results show that even at lipid surface compositions favoring two-phase systems, lipids are still extracted from solid, gel phase, domains into the surrounding fluid supported lipid bilayer surrounding the gel phase domains. The technique offers a means to obtain detailed knowledge of the chemical composition and organization of lipid membranes with potential application in systems where labeling is not possible, such as cell-derived supported lipid bilayers.

  • 15. Heim, C
    et al.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Lausmaa, J
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Leefmann, T
    Thiel, V
    Spectral characterisation of eight glycerolipid standards and detection in natural samples using time-of-flight secondary iion mass spectrometry2009In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 23, no 17, p. 2741-2753Article in journal (Refereed)
    Abstract [en]

    In recent years, time-of-flight secondary ion mass spectrometry (ToF-SIMS) with cluster ion sources has opened new perspectives for the analysis of lipid biomarkers in geobiology and organic geochemistry. However, published ToF-SIMS reference spectra of relevant compounds are still sparse, and the influence of the chemical environment (matrix) on the ionisation of molecules and their fragmentation is still not well explored. This study presents ToF-SIMS spectra of eight glycerolipids as common target compounds in biomarker studies, namely ester- and ether-bound phosphatidylethanolamine, ester- and ether-bound phosphatidylcholine, ester-bound phosphatidylcholine, ester- and ether-bound diglycerides and archaeol, obtained with a Bi 3 + cluster ion source. For all of these compounds, the spectra obtained in positive and negative analytical modes showed characteristic fragments that could clearly be assigned to e.g. molecular ions, functional groups and alkyl chains. By comparison with the reference spectra, it was possible to track some of these lipids in a pre-characterised organic extract and in cryosections of microbial mats. The results highlight the potential of ToF-SIMS for the laterally resolved analysis of organic biomarkers in environmental materials. The identification of the target compounds, however, may be hampered by matrix effects (e.g. adduct formation) and often require careful consideration of all spectral features and taking advantage of the molecular imaging capability of ToF-SIMS.

  • 16. Heindel, K
    et al.
    Birgel, D
    Brunner, B
    Thiel, V
    Westphal, H
    Gischler, E
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Post-glacial microbialate formation in coral reefs of the Pacific, Atlantic and Indian Oceans2012In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 304-305, p. 117-130Article in journal (Refereed)
    Abstract [en]

    The occurrence of microbialites in post-glacial coral reefs has been interpreted to reflect an ecosystem response to environmental change. The greater thickness of microbialites in reefs with a volcanic hinterland compared to thinner microbial crusts in reefs with a non-volcanic hinterland led to the suggestion that fertilization of the reefal environment by chemical weathering of volcanic rocks stimulated primary productivity and microbialite formation. Using a molecular and isotopic approach on reef-microbialites from Tahiti (Pacific Ocean), it was recently shown that sulfate-reducing bacteria favored the formation of microbial carbonates. To test if similar mechanisms induced microbialite formation in other reefs as well, the Tahitian microbialites are compared with similar microbialites from coral reefs off Vanuatu (Pacific Ocean), Belize (Caribbean Sea, Atlantic Ocean), and the Maldives (Indian Ocean) in this study. The selected study sites cover a wide range of geological settings, reflecting variable input and composition of detritus. The new lipid biomarker data and stable sulfur isotope results confirm that sulfate-reducing bacteria played an intrinsic role in the precipitation of microbial carbonate at all study sites, irrespective of the geological setting. Abundant biomarkers indicative of sulfate reducers include a variety of terminally-branched and mid chain-branched fatty acids as well as mono-O-alkyl glycerol ethers. Isotope evidence for bacterial sulfate reduction is represented by low δ 34S values of pyrite (-43 to -42‰) enclosed in the microbialites and, compared to seawater sulfate, slightly elevated δ 34S and δ 18O values of carbonate-associated sulfate (21.9 to 22.2‰ and 11.3 to 12.4‰, respectively). Microbialite formation took place in anoxic micro-environments, which presumably developed through the fertilization of the reef environment and the resultant accumulation of organic matter including bacterial extracellular polymeric substances (EPS), coral mucus, and marine snow in cavities within the coral framework. ToF-SIMS analysis reveals that the dark layers of laminated microbialites are enriched in carbohydrates, which are common constituents of EPS and coral mucus. These results support the hypothesis that bacterial degradation of EPS and coral mucus within microbial mats favored carbonate precipitation. Because reefal microbialites formed by similar processes in very different geological settings, this comparative study suggests that a volcanic hinterland is not required for microbialite growth. Yet, detrital input derived from the weathering of volcanic rocks appears to be a natural fertilizer, being conductive for the growth of microbial mats, which fosters the development of particularly abundant and thick microbial crusts.

  • 17. Jacobsson, Ulf
    et al.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Surface Analysis of Precision Weights for the Study of Commonly Occurring Contaminants: Chapter 332006In: Nanoscale Calibration Standards and Methods: Dimensional and Related Measurements in the Micro- and Nanometer Range / [ed] Günter Wilkening, Ludger Koenders, Wiley-VCH Verlagsgesellschaft, 2006, p. 434-442Chapter in book (Refereed)
  • 18.
    Jansson, Anna
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Carlred, Louise
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Borchardt, Per
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Sipilä, Konsta
    VTT, Finland.
    Joki, Harri
    VTT, Finland.
    Surface sensitive analysis for investigation of oxidation profiles in rubber sealing material2018Conference paper (Refereed)
    Abstract [en]

    Oxidation is the dominating degradation process in most polymers during long term use in nuclear power plant (NPP) applications. Under radiation, oxygen diffusion is known to be detrimental for poly-mers at room temperature and it is accelerated by increased temperature. Diffusion limited oxidation (DLO) has an effect to the heterogeneous oxidation behavior of polymers. [1]. During normal service of NPPs the temperature within the containment can be tens of degrees beyond room temperature. Also radiation levels can vary, depending on e.g. the reactor design, typically being less than 10 Gy/h during normal service [2].

    The long-term performance of polymeric materials is obviously best assessed by exposure of test specimens to natural ageing conditions followed by examination of their performance characteristics in terms of changes in physical properties. The testing conditions can be either in-door or out-door envi-ronments, and the first signs of degradation are often detected by testing mechanical properties such as tensile strength and elongation-at-break [3]. Although natural ageing is the most reliable

    exposure method for examining long-term performance, its use is restricted due to the extremely long exposure times required to achieve service lifetimes. In order to decrease the testing time significantly, and thereby achieve more rapid prediction of long-term behaviour of polymeric materials, artificial ac-celerated test methods involving harsher environments are used [4]. However, the accelerated ageing conditions cause at least two kinds of problems. Firstly, the chemistry of degradation can be markedly affected when the conditions of artificial ageing are too harsh. One consequence of this is a poor cor-relation with the changes that occur during natural ageing, resulting in misleading performance data. Secondly, all factors used in artificial ageing to induce chemical degradation and obtain observable physical changes must be accelerated to the same degree. However, neither the factors responsible for the ultimate degradation of a more or less complex polymeric system, nor the effects of their inter-relation are known. Consequently, it is essential that the analytical tools used to follow the ageing are capable of detecting and identifying differences between the employed accelerated tests and the natu-ral ageing already at an early stage of degradation. Moreover, sensitive tools can limit the need for high acceleration factors in artificial ageing.

    During accelerated ageing DLO effects may cause heterogeneous oxidation of the polymer which usu-ally does not occur to the same extent under normal service conditions at NPP. Combined to DLO ef-fects, understanding the combined effects of ionizing radiation and temperature is essential when evaluating the lifetime of polymeric components during normal service life or in Design Based Accident (DBA) situations.

    In order to study the oxygen containing degradation products on the surface compared to the bulk ma-terial a surface sensitive analytical instrument, Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS), was applied on EPDM samples. The aim is ultimately to evaluate the possibility to use ToF-SIMS in oxidation profile measurements. For comparisons this study includes differential scanning DSC, and Fourier transform infrared Spectroscopy (FTIR) as well as tensile testing.

  • 19.
    Jansson, Anna
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Polymer och fiber.
    Möller, Kenneth
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Analysis of polymer oxidation using 18O2 and TOF-SIMS2003In: Polymer Degradation and Stability, Vol. 80, no 80, p. 345-352Article in journal (Refereed)
  • 20.
    Johansson, L
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Energiteknik (ET).
    Tullin, C
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Energiteknik (ET).
    Leckner, B
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Energiteknik (ET).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Energiteknik (ET).
    Particle emissions from biomass combustion in small combustors.2003In: Biomass and Bioenergy, Vol. 25, p. 435-446Article in journal (Refereed)
  • 21. Kunze, A
    et al.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Kasemo, B
    Svedhem, S
    In situ preparation and modification of supported lipid layers by lipid transfer from vesicles studied by QCM-D and TOF-SIMS2009In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 131, no 7, p. 2450-2451Article in journal (Refereed)
    Abstract [en]

    The study of lipid transfer between lipid membranes is of great interest for the fundamental understanding of this complex and important process and, furthermore, for providing a new avenue for the in situ modification of supported lipid bilayers (SLBs). SLBs are conveniently formed by vesicle spreading onto a solid support, but this method is limited to conditions (i.e., combination of vesicle lipid composition, surface chemical properties, and buffer) such that the vesicles break spontaneously upon adsorption to the surface. Many SLB compositions are not accessible by this approach. In the present study, we give an example of how lipid transfer can be made use of to form lipid layers with striking new features, notably with respect to stability. After lipid transfer between negatively charged POPS small unilamellar vesicles and a positively charged POEPC SLB on TiO2, an SLB is obtained, which, upon exposure to SDS, leaves behind a lipid monolayer. It is shown how this monolayer can be used for creating new SLBs. The several step procedure, bilayer formation, lipid transfer, removal of a lipid monolayer and the reassembly of a bilayer, is monitored in real time by the quartz crystal microbalance with a dissipation (QCM-D) technique, and the lipid composition is analyzed for each step in postpreparation spectroscopic analyses using time-of-flight secondary ion mass spectrometry (TOF-SIMS). Comparison of the measured signal ratios with those of the reference samples containing known fractions of D31-POPS directly shows that the relative concentration of D31-POPS is 50% in the SLB after D31-POPS exchange, significantly higher in the monolayer prepared in situ by SDS rinse, and 20-25% after reassembly of the SLB using POEPC vesicles. The results thus provide unambiguous evidence for extensive lipid transfer between the initial POEPC SLB and D31-POPS vesicles in solution. We suggest that the reassembled SLB has a significant asymmetry between the two leaflets, and we propose that the described method is promising for the in situ preparation of asymmetric SLBs.

  • 22. Lanekoff, Ingela
    et al.
    Hill, Rowland
    Fletcher, John S.
    Vickerman, John C.
    Winograd, Nick
    Ewing, Andrew
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Kurczy, Michael E.
    Time of Flight Mass Spectrometry Imaging of Samples Fractured In Situ with a Spring-Loaded Trap System.2010In: Analytical Chemistry, Vol. 82, p. 6652-6659Article in journal (Refereed)
  • 23.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Siljeström, Sandra
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Hode, Tomas
    Toporski, Jan
    Thiel, Volker
    Detection of organic biomarkers in crude oil using ToF-SIMS2009In: Organic Geochemistry, Vol. 40, p. 135-143Article in journal (Refereed)
  • 24.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Analysis of archaeal core ether lipids using time-of-flight secondary ion mass spectrometry (ToF-SIMS): Exploring a new concept for the study of biomarkers in geobiology2007In: Geobiology, Vol. 5, p. 75-83Article in journal (Refereed)
  • 25.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Ancient microbial activity recorded in fracture fillings from granitic rocks (Äspö Hard Rock Laboratory, Sweden)2012In: Geobiology, ISSN 1472-4677, E-ISSN 1472-4669, Vol. 10, no 4, p. 280-297Article in journal (Refereed)
  • 26.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Comparison of exhaled endogenous particles from smokers and non-smokers using multivariate analysis2013In: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 86, no 2, p. 135-142Article in journal (Refereed)
  • 27.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Mass spectrometric imaging of lipids in brain tissue2004In: Anal. Chem., Vol. 76, p. 4271-4278Article in journal (Refereed)
  • 28.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    TOF-SIMS analysis of exhaled particles from patients with asthma and healthy controls2012In: European Respiratory Journal, ISSN 0903-1936, E-ISSN 1399-3003, Vol. 39, no 1, p. 59-66Article in journal (Refereed)
  • 29.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    TOF-SIMS imaging of lipids in cell membranes2005In: Surface and Interface Analysis, no Special Issue:Bio Surface and Interface Analysis, p. 1401-12Article in journal (Refereed)
    Abstract [en]

    Surface and Interface Analysis

  • 30.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Johansson, B
    Belazi, Dalila
    Stenvinkel, Peter
    Lindholm, Bengt
    Schalling, Martin
    TOF-SIMS analysis of adipose and muscle tissue from patients with chronic kidney disease2008In: Appl. Surface Sci, Vol. 255, p. 1177-1180Article in journal (Refereed)
  • 31.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Johansson, Björn
    Belazi, Dalila
    Stenvinkel, Peter
    Lindholm, Bengt
    Schalling, Martin
    TOF-SIMS analysis of adipose tissue from patients with chronic kidney disease.2008In: Applied Surface Science, Vol. 255, p. 1177-1180Article in journal (Refereed)
  • 32.
    Lausmaa, Jukka
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Siljeström, Sandra
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Hode, Tomas
    Analysis of single oil-bearing fluid inclusions in mid-Proterozoic sandstones (Roper Group, Australia)2013In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 122, p. 448-463Article in journal (Refereed)
  • 33.
    Leefman, Tim
    et al.
    Georg-August-University of Göttingen, Germany; Macquarie University, Australia.
    Heim, Christine
    Georg-August-University of Göttingen, Germany.
    Lausmaa, Jukka
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Ionescu, Danny
    Max Planck Institute for Marine Microbiology, Germany; Leibniz Institute for Freshwater Ecology and Inland Fisheries, Germany.
    Reitner, Joachim
    Georg-August-University of Göttingen, Germany.
    Thiel, Volker
    Georg-August-University of Göttingen, Germany.
    An Imaging Mass Spectrometry Study on the Formation of Conditioning Films and Biofilms in the Subsurface (Äspö Hard Rock Laboratory, SE Sweden)2015In: Geomicrobiology Journal, ISSN 0149-0451, E-ISSN 1521-0529, Vol. 32, no 3-4, p. 197-206Article in journal (Refereed)
    Abstract [en]

    Conditioning films and biofilms forming on surfaces of solid materials exposed to aqueous media play a key role in in the interaction between the geo- and biospheres. In this study, time-of-flight secondary ion mass spectrometry and scanning electron microscopy were used to investigate the time scale, mode of formation, and chemistry of conditioning films and biofilms that formed on Si substrates exposed to aquifer water in the subsurface Äspö Hard Rock Laboratory, SE-Sweden. The detection of fragment ions of amino acids, carbohydrates, and carboxylic acids revealed that different types of organic compounds had adhered to the Si surface already after 10 min of exposure to the aquifer fluids, whereas the attachment of microbial cells was first observed after 1000 min. The organic compounds first formed isolated μm-sized accumulations and subsequently started to distribute on the wafer surface more homogenously. Simultaneously further microorganisms attached to the surface and formed biofilm-like cell accumulations after 3 months of exposure to aquifer water.

  • 34.
    Lehti, Satu
    et al.
    Wihuri Research Institute, Finland.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Käkelä, Reijo
    University of Helsinki, Finland.
    Mäyränpää, Mikko I.
    University of Helsinki, Finland.
    Kovanen, Petri T.
    Wihuri Research Institute, Finland.
    Öörni, Katariina
    Wihuri Research Institute, Finland.
    Spatial distributions of lipids in atherosclerosis of human coronary arteries studied by time-of-flight secondary ion mass spectrometry2015In: American Journal of Pathology, ISSN 0002-9440, E-ISSN 1525-2191, Vol. 185, no 5, p. 1216-1233Article in journal (Refereed)
    Abstract [en]

    The accurate spatial distribution of various lipid species during atherogenesis has remained unexplored. Herein, we used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to analyze the lipid dis-tribution in human coronary artery cryosections. The images from the TOF-SIMS allowed visualization ofions derived from individual species of cholesterol esters, phospholipids, and triacylglycerols in thecontext of lesion characteristics and severity. In addition, cholesterol-containing crystal-like structureswere seen in high-resolution images of advanced lesions. The ratio of cholesterol fragment ions (m/z385:m/z 369) was found to differentiate unesterified cholesterol from cholesterol esters. This ratiochanged during atherogenesis and in different areas of the lesions, reflecting differences in theaccumulation of the two forms of cholesterol. Thus, atheromas were characterized by accumulation ofcholesterol esters with apolipoprotein B near the intima-media border, whereas in the complicatedlesions, unesterified cholesterol dominated in neovessel-containing areas enriched in glycophorin A.Interestingly, triacylglycerols were found in areas surrounding neovessels and lacking either form ofcholesterol. The lipid composition of the tunica media reflected the alterations observed in the intimallipids, yet being more subtle. The detailed molecular information obtained by TOF-SIMS revealedunanticipated differences in the type and composition of the accumulating lipids in different stages ofatherogenesis, notably the spatial segregation of cholesterol and triglycerides in the advancing lesions.

  • 35.
    Lindgren, J.
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Carney, R. M.
    Brown University, USA.
    Uvdal, P. D.
    Lund University, Sweden.
    Gren, J. A.
    Lund University, Sweden.
    Schultz, B. P.
    Muserum, Denmark.
    Shawkey, M. D.
    University of Akron, USA.
    Barnes, K. R.
    Mosasaur Ranch Museum, USA.
    Polcyn, M. J.
    Southern Methodist University, USA.
    Skin pigmentation provides evidence of convergent melanism in extinct marine reptiles2014In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 506, no 7489, p. 484-488Article in journal (Refereed)
    Abstract [en]

    Throughout the animal kingdom, adaptive colouration serves critical functions ranging from inconspicuous camouflage to ostentatious sexual display, and can provide important information about the environment and biology of a particular organism. The most ubiquitous and abundant pigment, melanin, also has a diverse range of non-visual roles, including thermoregulation in ectotherms. However, little is known about the functional evolution of this important biochrome through deep time, owing to our limited ability to unambiguously identify traces of it in the fossil record. Here we present direct chemical evidence of pigmentation in fossilized skin, from three distantly related marine reptiles: a leatherback turtle, a mosasaur and an ichthyosaur. We demonstrate that dark traces of soft tissue in these fossils are dominated by molecularly preserved eumelanin, in intimate association with fossilized melanosomes. In addition, we suggest that contrary to the countershading of many pelagic animals, at least some ichthyosaurs were uniformly dark-coloured in life. Our analyses expand current knowledge of pigmentation in fossil integument beyond that of feathers, allowing for the reconstruction of colour over much greater ranges of extinct taxa and anatomy. In turn, our results provide evidence of convergent melanism in three disparate lineages of secondarily aquatic tetrapods. Based on extant marine analogues, we propose that the benefits of thermoregulation and/or crypsis are likely to have contributed to this melanisation, with the former having implications for the ability of each group to exploit cold environments.

  • 36. Lindgren, J
    et al.
    Uvdal, P
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Nilsson, DE
    Engdahl, A
    Schultz, BP
    Molecular preservation of the pigment melanin in fossil melanosmoses2012In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 3, article id art no 824Article in journal (Refereed)
    Abstract [en]

    Fossil feathers, hairs and eyes are regularly preserved as carbonized traces comprised of masses of micrometre-sized bodies that are spherical, oblate or elongate in shape. For a long time, these minute structures were regarded as the remains of biofilms of keratinophilic bacteria, but recently they have been reinterpreted as melanosomes; that is, colour-bearing organelles. Resolving this fundamental difference in interpretation is crucial: if endogenous then the fossil microbodies would represent a significant advancement in the fields of palaeontology and evolutionary biology given, for example, the possibility to reconstruct integumentary colours and plumage colour patterns. It has previously been shown that certain trace elements occur in fossils as organometallic compounds, and hence may be used as biomarkers for melanin pigments. Here we expand this knowledge by demonstrating the presence of molecularly preserved melanin in intimate association with melanosome-like microbodies isolated from an argentinoid fish eye from the early Eocene of Denmark.

  • 37.
    Lindgren, Johan
    et al.
    Lund University, Sweden.
    Kuriyama, Takeo
    Lund University, Sweden; University of Hyogo, Japan; Wildlife Management Research Center, Japan.
    Madsen, Henrik
    Mo-clay Museum, Denmark.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Zheng, Wenxia
    North Carolina State University, USA; North Carolina Museum of Natural Sciences, USA.
    Uvdal, Per
    Lund University, Sweden.
    Engdahl, Anders
    Lund University, Sweden.
    Moyer, Alison E.
    North Carolina State University, USA.
    Gren, Johan A.
    Lund University, Sweden.
    Kamezaki, Naoki
    Okayama University of Science, Japan.
    Ueno, Shintaro
    University of Tokyo, Japan.
    Schweitzer, Mary H.
    Lund University, Sweden; North Carolina State University, USA; North Carolina Museum of Natural Sciences, USA.
    Biochemistry and adaptive colouration of an exceptionally preserved juvenile fossil sea turtle2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, no 1, article id 13324Article in journal (Refereed)
    Abstract [en]

    The holotype (MHM-K2) of the Eocene cheloniine Tasbacka danica is arguably one of the best preserved juvenile fossil sea turtles on record. Notwithstanding compactional flattening, the specimen is virtually intact, comprising a fully articulated skeleton exposed in dorsal view. MHM-K2 also preserves, with great fidelity, soft tissue traces visible as a sharply delineated carbon film around the bones and marginal scutes along the edge of the carapace. Here we show that the extraordinary preservation of the type of T. danica goes beyond gross morphology to include ultrastructural details and labile molecular components of the once-living animal. Haemoglobin-derived compounds, eumelanic pigments and proteinaceous materials retaining the immunological characteristics of sauropsid-specific β-keratin and tropomyosin were detected in tissues containing remnant melanosomes and decayed keratin plates. The preserved organics represent condensed remains of the cornified epidermis and, likely also, deeper anatomical features, and provide direct chemical evidence that adaptive melanism - a biological means used by extant sea turtle hatchlings to elevate metabolic and growth rates - had evolved 54 million years ago. © 2017 The Author(s).

  • 38.
    Lindgren, Johan
    et al.
    Lund University, Sweden.
    Moyer, Alison E.
    North Carolina State University, US.
    Schweitzer, Mary Higby
    Lund University, Sweden; North Carolina State University, US; North Carolina Museum of Natural Sciences, US.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Uvdal, Peter
    Lund University, Sweden.
    Nilsson, Dan Eric
    Lund University, Sweden.
    Heimdal, Jimmy
    Lund University, Sweden.
    Engdahl, Anders
    Lund University, Sweden.
    Gren, Johan A.
    Lund University, Sweden.
    Schultz, Bo Pagh
    MUSERUM, Denmark.
    Kear, Benjamin P.
    Uppsala University, Sweden.
    Interpreting melanin-based coloration through deep time: A critical Review2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, no 1813, article id 20150614Article, review/survey (Refereed)
    Abstract [en]

    Colour, derived primarily from melanin and/or carotenoid pigments, is integral to many aspects of behaviour in living vertebrates, including social signalling, sexual display and crypsis. Thus, identifying biochromes in extinct animals can shed light on the acquisition and evolution of these biological traits. Both eumelanin and melanin-containing cellular organelles (melanosomes) are preserved in fossils, but recognizing traces of ancient melanin-based coloration is fraught with interpretative ambiguity, especially when observations are based on morphological evidence alone. Assigning microbodies (or, more often reported, their ‘mouldic impressions’) as melanosome traces without adequately excluding a bacterial origin is also problematic because microbes are pervasive and intimately involved in organismal degradation. Additionally, some forms synthesize melanin. In this review, we survey both vertebrate and microbial melanization, and explore the conflicts influencing assessment of microbodies preserved in association with ancient animal soft tissues.We discuss the types of data used to interpret fossil melanosomes and evaluate whether these are sufficient for definitive diagnosis. Finally, we outline an integrated morphological and geochemical approach for detecting endogenous pigment remains and associated microstructures in multimillion-year-old fossils.

  • 39.
    Lindgren, Johan
    et al.
    Lund University, Sweden.
    Nilsson, Dan Eric
    Lund University, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Jarenmark, Martin
    Lund University, Sweden.
    Ito, Shosuke
    Fujita Health University School of Health Sciences, Japan.
    Wakamatsu, Kazumasa
    Fujita Health University School of Health Sciences, Japan.
    Kear, Benjamin
    Uppsala University, Sweden.
    Schultz, Bo
    Fur Museum, Denmark.
    Sylvestersen, Rene
    Fur Museum, Denmark.
    Madsen, Henrik
    Mo-clay Museum, Denmark.
    LaFountain, James
    University at Buffalo, US.
    Alwmark, Carl
    Lund University, Sweden.
    Eriksson, Mats
    Lund University, Sweden.
    Hall, Stephen
    Lund University, Sweden.
    Lindgren, Paula
    Lund University, Sweden.
    Rodríguez-Meizoso, Irene
    Lund University, Sweden.
    Ahlberg, Per
    Lund University, Sweden.
    Fossil insect eyes shed light on trilobite optics and the arthropod pigment screen2019In: Nature, ISSN 0028-0836, E-ISSN 1476-4687Article in journal (Refereed)
    Abstract [en]

    Fossilized eyes permit inferences of the visual capacity of extinct arthropods1–3. However, structural and/or chemical modifications as a result of taphonomic and diagenetic processes can alter the original features, thereby necessitating comparisons with modern species. Here we report the detailed molecular composition and microanatomy of the eyes of 54-million-year-old crane-flies, which together provide a proxy for the interpretation of optical systems in some other ancient arthropods. These well-preserved visual organs comprise calcified corneal lenses that are separated by intervening spaces containing eumelanin pigment. We also show that eumelanin is present in the facet walls of living crane-flies, in which it forms the outermost ommatidial pigment shield in compound eyes incorporating a chitinous cornea. To our knowledge, this is the first record of melanic screening pigments in arthropods, and reveals a fossilization mode in insect eyes that involves a decay-resistant biochrome coupled with early diagenetic mineralization of the ommatidial lenses. The demonstrable secondary calcification of lens cuticle that was initially chitinous has implications for the proposed calcitic corneas of trilobites, which we posit are artefacts of preservation rather than a product of in vivo biomineralization4–7. Although trilobite eyes might have been partly mineralized for mechanical strength, a (more likely) organic composition would have enhanced function via gradient-index optics and increased control of lens shape.

  • 40.
    Lindgren, Johan
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Carney, Ryan M.
    Brown University, US.
    Cincotta, Aude
    Royal Belgian Institute of Natural Sciences; Belgium; University of Namur, Belgium.
    Uvdal, Per
    Lund University, Sweden.
    Hutcheson, Steven W.
    University of Maryland, US.
    Gustafsson, Ola
    Lund University, Sweden.
    Lefèvre, Ulysse
    Royal Belgian Institute of Natural Sciences, Belgium; Liège University, Belgium.
    Escuillié, Francois
    Eldonia, France.
    Heimdal, Jimmy
    Lund University, Sweden.
    Engdahl, Anders
    Lund University, Sweden.
    Gren, Johan A.
    Lund University, Sweden.
    Kear, Benjamin P.
    Uppsala University, Sweden.
    Wakamatsu, Kazumasa
    Fujita Health University, Japan.
    Yans, Johan
    University of Namur, Belgium.
    Godefroit, Pascal
    Royal Belgian Institute of Natural Sciences, Belgium.
    Molecular composition and ultrastructure of Jurassic paravian feathers2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, article id 13520Article in journal (Refereed)
    Abstract [en]

    Feathers are amongst the most complex epidermal structures known, and they have a well-documented evolutionary trajectory across non-avian dinosaurs and basal birds. Moreover, melanosome-like microbodies preserved in association with fossil plumage have been used to reconstruct original colour, behaviour and physiology. However, these putative ancient melanosomes might alternatively represent microorganismal residues, a conflicting interpretation compounded by a lack of unambiguous chemical data. We therefore used sensitive molecular imaging, supported by multiple independent analytical tests, to demonstrate that the filamentous epidermal appendages in a new specimen of the Jurassic paravian Anchiornis comprise remnant eumelanosomes and fibril-like microstructures, preserved as endogenous eumelanin and authigenic calcium phosphate. These results provide novel insights into the early evolution of feathers at the sub-cellular level, and unequivocally determine that melanosomes can be preserved in fossil feathers.

  • 41.
    Lindgren, Johan
    et al.
    Lund University, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Thiel, Volker
    University of Göttingen, Germany.
    Zheng, Wenxia
    North Carolina State University, USA.
    Ito, Shosuke
    Fujita Health University School of Health Sciences, Japan.
    Wakamatsu, Kazumasa
    Fujita Health University School of Health Sciences, Japan.
    Hauff, Rolf Bernhard
    Urweltmuseum Hauff, Germany.
    Kear, Benjamin P.
    Uppsala University, Sweden.
    Engdahl, Anders
    Lund University, Sweden.
    Alwmark, Carl
    Lund University, Sweden.
    Eriksson, Mats Erik
    Lund University, Sweden.
    Jarenmark, Martin
    Lund University, Sweden.
    Sachs, Sven
    Naturkunde-Museum Bielefeld, Germany.
    Ahlberg, Per Erik
    Uppsala University, Sweden.
    Marone, Federica
    Paul Scherrer Institute, Switzerland.
    Kuriyama, Takeo
    University of Hyogo, Japan; Wildlife Management Research Center, Japan.
    Gustafsson, Ola S.E.
    Lund University, Sweden.
    Malmberg, Per
    Chalmers University of Technology, Sweden.
    Thomen, Aurélien
    University of Gothenburg, Sweden.
    Rodríguez-Meizoso, Irene
    Lund University, Sweden.
    Uvdal, Per E.
    Lund University, Sweden.
    Ojika, Makoto
    Nagoya University, Japan.
    Schweitzer, Mary Higby
    Lund University, Sweden; North Carolina State University, USA; North Carolina Museum of Natural Sciences, USA.
    Soft-tissue evidence for homeothermy and crypsis in a Jurassic ichthyosaur2018In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 564, no 7736, p. 359-365Article in journal (Refereed)
    Abstract [en]

    Ichthyosaurs are extinct marine reptiles that display a notable external similarity to modern toothed whales. Here we show that this resemblance is more than skin deep. We apply a multidisciplinary experimental approach to characterize the cellular and molecular composition of integumental tissues in an exceptionally preserved specimen of the Early Jurassic ichthyosaur Stenopterygius. Our analyses recovered still-flexible remnants of the original scaleless skin, which comprises morphologically distinct epidermal and dermal layers. These are underlain by insulating blubber that would have augmented streamlining, buoyancy and homeothermy. Additionally, we identify endogenous proteinaceous and lipid constituents, together with keratinocytes and branched melanophores that contain eumelanin pigment. Distributional variation of melanophores across the body suggests countershading, possibly enhanced by physiological adjustments of colour to enable photoprotection, concealment and/or thermoregulation. Convergence of ichthyosaurs with extant marine amniotes thus extends to the ultrastructural and molecular levels, reflecting the omnipresent constraints of their shared adaptation to pelagic life.

  • 42.
    Lu, Xiaohu
    et al.
    Nynas AB, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Soenen, Hilde
    Nynas NV, Belgium.
    Andersson, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Microstructures of bitumen observed by environmental scanning electron microscopy (ESEM) and chemical analysis using time-of-flight secondary ion mass spectrometry (TOF-SIMS)2018In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 229, p. 198-208Article in journal (Refereed)
    Abstract [en]

    The aim of this study is to characterize structures induced on bitumen surfaces under analysis by environmental scanning electron microscopy (ESEM), and to examine possible contributing factors to the formation of their formation. Various bitumen samples are investigated, including soft and hard, as well as polymer modified bitumen. Chemical characterization is carried out by time-of-flight secondary ion mass spectrometry (TOF-SIMS), combined with principle component analysis (PCA). The study shows that, for soft bitumen, a tube pattern or worm structure is rapidly formed during ESEM analysis, but for hard bitumen, a longer exposure time is needed to develop a structure. The structures on the hard bitumen are also denser as compared to those on the soft bitumen. When sample specimens are deformed or stretched, the orientation of the created deformation is clearly reflected in the structures formed under ESEM, and for soft bitumen, the structure disappears overnight in vacuum but reappears with the same pattern upon repeated ESEM analysis. TOF-SIMS shows small but consistent chemical differences, indicating higher aliphatic and lower aromatic contents on the surface of the structured area compared to the unstructured area. Based on an estimated temperature increase on the bitumen surface due to the electron-beam irradiation, it is speculated that the ESEM-induced worm structure may be attributed to evaporation of volatiles, surface hardening and local expansion. In addition, under the electron-beam exposure, certain chemical reactions (e.g. breaking of chemical bonds, chain scission and crosslinking) may take place, possibly resulting in the observed chemical differences between the structured and unstructured areas.

  • 43.
    Lu, Xiaohu
    et al.
    Nynas AB, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Soenen, Hilde
    Nynas NV, Belgium.
    Blom, Johan
    Antwerp University, Belgium.
    Andersson, Martin
    RISE - Research Institutes of Sweden, Bioscience and Materials, Surface, Process and Formulation.
    Visualization and chemical analysis of bitumen microstructures2019In: RILEM Bookseries, 2019, p. 168-173Conference paper (Refereed)
    Abstract [en]

    Microstructures of bitumen were investigated using atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM), and a chemical characterization was successfully carried out using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The bee structures were observed by AFM, for which a chemical explanation by wax was confirmed by the TOF-SIMS analysis. A tube pattern or worm structures were generated and visualized by ESEM on bitumen surfaces. Chemical differences between the structured and unstructured areas, as well as between different areas of the structure, were observed. A mechanism for the structure formation on bitumen surface during ESEM analysis is suggested.

  • 44.
    Lu, Xiauhu
    et al.
    Nynas AB, Sweden.
    Sjövall, Peter
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Soenen, Hilde
    Nynas NV, Belgium.
    Structural and chemical analysis of bitumen using time-of-flight secondary ion mass spectrometry (TOF-SIMS)2017In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 199, p. 206-218Article in journal (Refereed)
    Abstract [en]

    The chemical composition and structures of bitumen surfaces are characterised using time-of-flight secondary ion mass spectrometry (TOF-SIMS). The effect of wax is considered by comparing a wax-free bitumen with a bitumen that contains natural wax and a wax-free bitumen to which a small amount of wax has been added. The results demonstrate that TOF-SIMS is a powerful method for the chemical characterisation of surface structures and phase segregation phenomena in bitumen. It is evident that the structures formed on the bitumen surface are closely related to the wax content and that these structures, as well as the surface in general, are enriched in wax-related compounds (aliphatic hydrocarbons with a high degree of saturation). For the wax-free bitumen, the surface is characterised by a homogeneous distribution without chemical variations or phase structures and by a stronger signal intensity from aromatic compounds. When adding wax to the wax-free bitumen, extensive wax segregation occurs, but differently from the natural waxy bitumen, no bee structures are observed. Furthermore, fracture surfaces of all the wax-containing samples reveal circular structures, which are distinctly different from those observed on the original surfaces. The obtained chemical knowledge on bitumen surfaces and phase structures is of fundamental importance to understand performance differences of this type of materials.

  • 45. Magnusson, Y
    et al.
    Friberg, P
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Dangardt, F
    Malmberg, P
    Chen, Y
    Lipid imaging of human skeletal muscle using TOF-SIMS with bismuth cluster ion as a primary ion source2008In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 28, no 3, p. 202-209Article in journal (Refereed)
    Abstract [en]

    Intramyocellular lipids are of importance in lipid-related diseases. The techniques in this field are limited because of a lack of adequate tools for localization of various lipids. The most usual methods for the localization of lipid distribution in the skeletal muscle are histochemistry and fluorescence probes. Different chromatography methods and mass spectrometry techniques have also been used for lipid identification. Our aim was to localize the spatial distribution of lipids in their native forms by using static time-of-flight secondary-ion mass spectrometry (TOF-SIMS). Human percutaneous skeletal muscle biopsies were obtained from the middle part of the lateral vastus muscle in the right leg of healthy adolescents with a body mass index >30. Samples were prepared by high-pressure freezing, freeze-fracturing and freeze-drying, and analysed by imaging TOF-SIMS equipped with a Bi3+ cluster ion gun. In the positive spectra, we identified phosphocholine, cholesterol, diacylglycerol, phospholipids and triacylglycerol. Phosphocholine was localized to the edge of the fibre, representing the sarcoplasma or endomysium. Weak cholesterol signals were observed in the intracellular areas. High diacylglycerol and low triacylglycerol signal intensities were seen in intracellular spaces of the transversal area of the muscle fibre. In the negative spectra, we identified fatty acids. We observed co-localization of fatty acids and diacylglycerol, which may indicate lipid-storing parts of the skeletal muscle. Thus, TOF-SIMS imaging can be used to depict the heterogeneous localization of lipids in human skeletal muscle.

  • 46. Malm, J
    et al.
    Giannaras, D
    Riehle, MO
    Gadagaard, N
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, YKI – Ytkemiska institutet.
    Fixation and drying protocols for the preparation of cell samples for time-of-flight secondary ion mass spectrometry analysis2009In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 81, no 17, p. 7197-7205Article in journal (Refereed)
    Abstract [en]

    Time-of-flight secondary ion mass spectrometry (TOFSIMS) is a promising tool for subcellular chemical analysis of biological cells. However, to obtain relevant information, the method used for sample preparation is critical. In this work, we have used TOF-SIMS, scanning electron microscopy (SEM), and interference reflection microscopy (IRM) to study the effects of different fixation and drying methods on the morphology and chemical structure of human fibroblast cells (hTERT) adhered to a silicon surface. Specifically, two fixation techniques (chemical fixation with glutaraldehyde and cryofixation by plunge freezing) and two drying techniques (freeze drying and alcohol substitution drying) were investigated. Cryofixation followed by freeze drying was determined to produce dried cells with preserved cell morphology, intact cell membranes, and retained sodium/potassium ion concentration gradients across the plasma membrane. By washing samples in an aqueous solution of ammonium formate (AF) before cryofixation, the accumulation of salts on the sample surface during drying could be suppressed. IRM measurements showed that the cell morphology was preserved during washing with ammonium formate, although some swelling occurred. Compared with cryofixation, cells fixed with glutaraldehyde showed finer structures on the cell surface in SEM and similar lipid distributions in TOF-SIMS, but the sodium/potassium ion gradients were not retained. Alcohol drying was determined to remove cell membrane phospholipids significantly, although the use of osmium tetroxide as a post-fixative was shown to decrease this effect.

  • 47. Maria de Peppo, Giuseppe
    et al.
    Bigdeli, Narmin
    Lennerås, Maria
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Lindahl, Anders
    Karlsson, Camilla
    Hyllner, Johan
    Superior osteogenic capacity of human embryonic stem cells adapted to matrix-free growth compared to human mesenchymal stem cells2010In: Tissue Engineering A, Vol. 16, p. 3427-3440Article in journal (Refereed)
  • 48. Maria de Peppo, Giuseppe
    et al.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Lennerås, Maria
    Strehl, Raimund
    Hyllner, Johan
    Thomsen, Peter
    Karlsson, Camilla
    Osteogenic Potential of Human Mesenchymal Stem Cells and Human Embryonic Stem Cell-derived Mesodermal Progenitors: a Tissue Engineering Perspective2010In: Tissue Engineering A, Vol. 16, p. 3413-3426Article in journal (Refereed)
    Abstract [en]

    Tissue Engineering A, 16(11):3413-3426, 2010

  • 49.
    Möller, Kenneth
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Jansson, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Polymer och fiber.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Analysis of oxidative polymer degradation using 18O and TOF-SIMS spectrometry2002Conference paper (Other academic)
  • 50.
    Möller, Kenneth
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik.
    Jansson, Anna
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Polymer och fiber.
    Sjövall, Peter
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Funktionella material (KMf).
    Degradation of post-consumer polypropylene materials exposed to simulated recycling – mechanical properties2003In: Polymer Degradation and Stability, Vol. 82, p. 37-46Article in journal (Refereed)
123 1 - 50 of 108
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