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- Thiel, V, et al.
(författare)
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Analysis of archaeal core ether lipids using Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS): Exploring a new prospect for the study of biomarkers in geobiology
- 2007
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Ingår i: Geobiology. - 1472-4677 .- 1472-4669. ; 5:1, s. 75-83
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Tidskriftsartikel (refereegranskat)abstract
- The capability of Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) of analysing molecular archaeal biomarkers in geobiological samples was tested and demonstrated. Using a bismuth cluster primary ion source, isopranyl glycerol di- and tetraether core lipids were detected in small amounts of total organic extracts from methanotrophic microbial mats, simultaneously and without further chemical treatment and chromatographic separation. ToF-SIMS was also employed to track the distribution of fossilized ether lipids in a massive carbonate (aragonite) microbialite that precipitated as a result of the microbial anaerobic oxidation of methane. An unambiguous signal was obtained when analysing a freshly broken rock surface (base of a microdrill core). Though some limitation occurred due to μm-topographical effects (sample roughness), it was possible to display the abundance of high molecular weight (C86) of tetraethers exposed in particular regions of the rock surface. 'Molecular mapping' revealed that a part of these molecules was encased within the rock fabric in a cluster-like distribution that might trace the arrangement of the calcifying microbial colonies in the once active mat system. The results reveal promising perspectives of ToF-SIMS for (i) the quasi-nondestructive analysis of lipids in extremely small geobiological samples at low concentrations; (ii) resolving the spatial distribution of these compounds on a μm2- to cm2-scale; and (iii) the more exact assignment of lipid biomarkers to their biological source. © 2006 The Authors.
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| 4. |
- Chappuis, S, et al.
(författare)
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Photocatalytically active titania layers: Production at ambient temperature and characterisation of biological properties
- 2009
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Ingår i: Plasma Processes and Polymers. - : Wiley. - 1612-8850 .- 1612-8869. ; 6:6-7, s. 440-445
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Tidskriftsartikel (refereegranskat)abstract
- The production of phase-pure, photocatalytically active titania layers at ambient temperature is described. This novel synthesis route has been achieved by using direct-current reactive magnetron sputtering as well as plasma-enhanced chemical vapour deposition processes. As a consequence substrates degrading under increased temperature such as, e.g., polymers, biological fibres, tissues, etc., may be coated. The obtained titania coatings are characterised with respect to structure, morphology, phase purity and biological activity. The results of these investigations confirm promising and reproducible photocatalytic, biocompatible as well as bioactive properties. A figure is presented.
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| 5. |
- de Peppo, Giuseppe Maria, 1981, et al.
(författare)
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Free-form-fabricated commercially-pure Ti and Ti6Al4V porous scaffolds support the growth of human embryonic stem cell-derived medsodermal progenitors
- 2012
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Ingår i: The Scientific World Journal. - : Hindawi Limited. - 2356-6140 .- 1537-744X. ; 2012
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Tidskriftsartikel (refereegranskat)abstract
- Commercially-pure titanium (cp-Ti) and the titanium-aluminum-vanadium alloy (Ti6Al4V) are widely used as reconstructive implants for skeletal engineering applications, due to their good mechanical properties, biocompatibility and ability to integrate with the surrounding bone. Electron beam melting technology (EBM) allows the fabrication of customized implants with tailored mechanical properties and high potential in the clinical practice. In order to augment the interaction with the biological tissue, stem cells have recently been combined with metallic scaffolds for skeletal engineering applications. We previously demonstrated that human embryonic stem cell-derived mesodermal progenitors (hES-MPs) hold a great potential to provide a homogeneous and unlimited supply of cells for bone engineering applications. This study demonstrates the effect of EBM-fabricated cp-Ti and Ti6Al4V porous scaffolds on hES-MPs behavior, in terms of cell attachment, growth and osteogenic differentiation. Displaying different chemical composition but similar surface properties, EBM-fabricated cp-Ti and Ti6Al4V scaffolds supported cell attachment and growth, and did not seem to alter the expression of genes involved in osteogenic differentiation and affect the alkaline phosphatase activity. In conclusion, interfacing hES-MPs to EBM-fabricated scaffolds may represent an interesting strategy for design of third-generation biomaterials, with the potential to promote implant integration in clinical conditions characterized by poor bone quality. Copyright 2012 G. M. de Peppo et al.
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| 6. |
- Englund, F., et al.
(författare)
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Spectroscopic studies of surface chemical composition and wettability of modified wood
- 2009
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Ingår i: Wood Material Science & Engineering. - : Taylor & Francis Group. - 1748-0272 .- 1748-0280. ; 4:1-2, s. 80-85
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in spectroscopic methods used in the surface science field may provide new valuable information about the surface chemical composition of engineering materials. Such methods, combined with wettability analyses, have been applied in the development of well-designed adhesives and coating systems for newly developed and commercially available modified wood materials. The main objective of this paper is to demonstrate and present some aspects on the application of two different state-of-the-art spectroscopic methods for surface chemical composition studies of a complex material such as modified wood. The methods are X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), the former generating more quantitative data and the latter more qualitative data. The spectroscopic data are also combined with wettability data obtained from contact angle measurements using the Wilhelmy method. Modified wood samples were prepared from pilot plant or commercially produced acetylated, furfurylated and thermally modified wood. Effects of wood surface ageing, i.e. the time after machining, on the surface chemical composition and wettability were also studied. Results clearly indicate a hydrophobization process due to ageing of the unmodified and certain modified wood, probably mainly related to a migration and reformation of extractives in the surface. The surface composition and wettability of acetylated wood was not appreciably affected by the ageing process. Such findings could be quantified by the XPS measurements, which is further discussed and related to the different wood modification routes. ToF- SIMS is a powerful tool and complementary to XPS for identification of, for example, specific hydrophobic substances in the wood surfaces. In addition, this method provides ion images, mapping the lateral distribution of selected secondary ions signals within an analysed wood surface area.
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| 8. |
- Heim, C, et al.
(författare)
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Spectral characterisation of eight glycerolipid standards and detection in natural samples using time-of-flight secondary iion mass spectrometry
- 2009
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Ingår i: Rapid Communications in Mass Spectrometry. - 0951-4198 .- 1097-0231. ; 23:17, s. 2741-2753
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Holopainen, Riikka, et al.
(författare)
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Physiotherapists’ validating and invalidating communication before and after participating in brief cognitive functional therapy training : Test of concept study
- 2023
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Ingår i: European Journal of Physiotherapy. - : Taylor & Francis. - 2167-9169 .- 2167-9177. ; 25:2, s. 73-79
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim of this study was to investigate physiotherapists' validating and invalidating communication, before and after brief Cognitive Functional Therapy (CFT) training that included a session on validation skills. Associations between validation/invalidation and the characteristics of the interviews and physiotherapists were also explored.Methods: Eighteen physiotherapists treating patients with low back pain participated in the study. The study had a within-group design in which validation and invalidation for physiotherapists were rated before and after training using a reliable observational scale. We also collected data on interview length and physiotherapists' and patients' speech percentages.Results: The physiotherapists' validating responses increased and invalidating responses decreased from pre- to post-training. The within-group effect size was large for validating responses and medium for invalidating responses. The interview length increased from pre- to post-training (large effect size). However, the reason for this was related to factors other than validation and invalidation. The results indicate that increased validation is associated with an increase in physiotherapists' speech percentage.Conclusions: The results of this study show changes invalidating and invalidating communication among physiotherapists from pre- to post-CFT training. The study also found associations between specific interview characteristics and validating communication. Future studies with larger samples and control groups are needed.
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