| 81. |
- Svensson, Olof, et al.
(författare)
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Adsorption of delmopinol at the solid/liquid interface - the role of the acid-base equilibrium
- 2010
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier Inc.. - 0021-9797 .- 1095-7103. ; 350:1, s. 275-281
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Tidskriftsartikel (refereegranskat)abstract
- Delmopinol is a tertiary amine surfactant that is used to counteract dental plaque formation. As it is of interest to understand the interfacial behavior from both fundamental and applied perspectives the adsorption of delmopinol to model surfaces was investigated. Adsorption on Teflon, titanium and stainless steel was studied by radioactive labeling and adsorption on silica was studied by quartz crystal microbalance (QCM), ellipsometry and particle electrophoresis. It was shown that the adsorption of delmopinol was complex and strongly influenced by pH and concentration. Pronounced peak values were detected in the adsorption curves (adsorbed amount versus concentration) exceeding the expected value for a bilayer type of structure. To account for this behavior two surface active component were assumed to be present. Accordingly, the high amounts result from the deposition of the component with lower solubility and the decrease at the critical micelle concentration can be explained by solubilization of this component. Based on data from several experimental methods and the pH dependence of the effect we propose an explanation in which the protonated and non-protonated forms of delmopinol represent the two components. However, it cannot be excluded that the component with the lower solubility could be a compound chemically different from delmopinol in the sample.
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| 82. |
- Svensson, Olof, et al.
(författare)
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Adsorption of serum albumin on silica : The influence of surface cleaning procedures
- 2010
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier Inc.. - 0021-9797 .- 1095-7103. ; 344:1, s. 44-47
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the investigation was to study how different surface cleaning procedures affect the subsequent adsorption of bovine serum albumin (BSA) on silica. Ellipsometry was used to monitor the adsorbed amount and thickness of the protein films in situ at physiological buffer conditions. Plasma treatment was found to effectively reduce the amount of BSA on silica and on surfaces cleaned with hydrogen peroxide solutions (RCA method) adsorption was essentially absent. On clean silica surfaces the ellipsometric data furthermore suggest that a depletion zone is present at the surface where the BSA concentration is lower than in the bulk solution. Additional experiments showed that calcium did not promote the adsorption of BSA and that the adsorption of human serum albumin (HSA) is essentially absent on clean silica surfaces in agreement with the results obtained for BSA. The presented work contributes to the general understanding of protein adsorption as well as provides information on how to control serum albumin adsorption on silica based biomedical devices.
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| 83. |
- Svensson, Olof, et al.
(författare)
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Antibody–antigen interaction on polystyrene : An in situ ellipsometric study
- 2012
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier. - 0021-9797 .- 1095-7103. ; 368:1, s. 533-539
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this investigation was to monitor the adsorption of antibodies to polystyrene surfaces using ellipsometry. Commercial polystyrene slides used for solid state diagnostics were selected as substrates and the adsorption of three different antibodies (human IgG, bovine IgG and goat anti-human IgG) were evaluated. Based on theoretical models describing the ellipsometric data, it was concluded that the adsorption of antibodies should result in layers that are sufficiently thick to be able to monitor the adsorption in terms of adsorbed amount and thickness of the layer with a reasonable precision. The experimental results confirmed this assumption and values of 2.0–2.3 mg/m2 were detected for the adsorbed amount with a corresponding thickness of 10–16 nm. It was furthermore found that the antibodies bound irreversibly with respect to rinsing with protein-free solutions. In additional experiments, the consecutive incubation of human IgG and anti-human IgG was investigated. These results showed that, on average, approximately half of the surface immobilized anti-human IgG molecules are capable of binding to human IgG during its incubation. From the consecutive binding experiments it could also be concluded that antibodies present in the polyclonal anti-human IgG preparation were capable of binding to around four different epitopes on the human IgG. A final set of experiments addressed the stability of adsorbed human IgG layers with respect to drying and incubation with surfactant. The results revealed that the adsorbed antibody layer is relatively resistant to these treatments.
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| 84. |
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| 85. |
- Svensson, Olof, et al.
(författare)
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Mucin layers and multilayers — Physicochemical properties and applications
- 2010
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Ingår i: Current Opinion in Colloid & Interface Science. - : Elsevier. - 1359-0294 .- 1879-0399. ; 15:6, s. 395-405
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- The present review summarizes recent, and important previous, findings on properties of mucin layers and multilayers and ways to tailor their properties. Specifically, progress has been made in understanding the effects of mucin type, preparations, ambient conditions and surface properties on adsorption and on mixed layer assembly including multilayers. Apart from structural features the stability, lubrication and biological functions of such layers are addressed.
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| 86. |
- Svensson, Peter, 1974-
(författare)
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The Dynamics of Innovation and Knowledge-Based Regional Development
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Geographical regions as diverse as Silicon Valley, California and Linköping, Sweden have been the sources of new technology and endogenously created innovations. Scholars and policymakers recognise that specific regions or clusters of businesses have the capability to engage in more innovative activities and new business formation and to experience higher employment growth than others. This dissertation uses qualitative methods to study various aspects of regional development and innovation. It is based on five papers by the author and colleagues with levels of analysis ranging from regional to firms’ first sales in order to capture the dynamics of both the top and bottom levels of regional development. It then uses these papers’ empirical material to address the research questions of (a) how a new scientific knowledge base becomes established and exploited in a spatial context, and (b) how people create and diffuse innovations in a social and spatial context. This dissertation’s main findings are that (a) regional leadership involving the building of alliances with triple-helix actors is crucial for initiating a knowledge-based regional development process, (b) a consensus space is a catalytic mechanism for ensuring the speed and effectiveness of regional development, (c) lowering the barriers for the actors involved boosts participation and the rate of innovation, and (d) users’ perspectives are essential for social, institutional and commercial innovation. This dissertation’s main implications are that knowledge-based regional development’s initial stages require leadership that (a) builds alliances and establish an arena for the triple-helix actors, (b) analyses the regional barriers to the commercialisation of knowledge, and (c) utilises both endogenous and exogenous resources.
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| 87. |
- Sörman, Karolina, et al.
(författare)
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Forensic Mental Health Professionals’ Perceptions of Psychopathy : a Prototypicality Analysis of the Comprehensive Assessment of Psychopathic Personality in Sweden
- 2014
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Ingår i: Law and human behavior. - : American Psychological Association (APA). - 0147-7307 .- 1573-661X. ; 38:5, s. 405-417
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Tidskriftsartikel (refereegranskat)abstract
- Assessments of psychopathic traits are used on a routine basis in forensic evaluations across Westernized countries. Despite this, consensus has not yet emerged concerning what exactly are the “core” features of this construct. Moreover, relatively little is known about how practitioners in the field construe this disorder. This study explored perceptions and attitudes regarding psychopathy among individuals working in the forensic mental health system (N = 90) in Sweden. Participants provided prototype ratings of what they considered to be core psychopathy features based on the Comprehensive Assessment of Psychopathic Personality (CAPP), a model that increasingly is the focus of research in North America and Europe. The study protocol also included questions regarding (a) global perceptions and attitudes about a number of aspects of the psychopathy construct (e.g., personal experience, perceived prevalence), and (b) attitudinal scales that assessed perceived correlates of psychopathic traits across a variety of domains (e.g., violence proneness, treatment amenability) and moral judgments and attitudes concerning how psychopathic offenders should be treated within the legal system. The majority of the 33 individual CAPP items and the six CAPP scales were rated as at least moderately prototypical of psychopathy, with Dominance, Self, and Attachment domains obtaining the highest mean ratings. Participants viewed psychopaths as more likely to commit crimes than the average criminal, without being blatantly “evil” people. We believe our results help to advance our understanding of the psychopathy construct by exploring forensic professionals’ perceptions of this disorder in general and in relation to the CAPP model specifically.
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| 88. |
- Talle, Malin, et al.
(författare)
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Mowing for biodiversity : grass trimmer and knife mower perform equally well
- 2014
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 23:12, s. 3073-3089
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Tidskriftsartikel (refereegranskat)abstract
- Mowing of semi-natural grasslands is an important management method to maintain the conservation value and species-richness of this habitat. Mowing using cutting instruments, e.g. sickle bar mowers, is thought to be superior by practitioners compared with other mechanical instruments that tears off the plant material, e.g. grass trimmers. However, almost no studies exist that supports this assumption. We analysed a 12-year field trial in a semi-natural grassland in south-eastern Sweden, with the aim of determining which mowing technique best maintains the conservation value of semi-natural grasslands. Two mowing techniques were compared: mowing using a hand-pushed sickle bar mower (a type of knife mower), or mowing using a grass trimmer at a 5-cm or 0-cm cutting height. The odds that a recorded species belongs to a group of indicator species were calculated for sample plots, and odds ratios were calculated contrasting treatments. Three types of indicator species classification systems were used: (i) indicators of management for species richness, (ii) indicators of excess nitrogen and (iii) indicators of lack of management. The odds ratios were calculated for years 1-5, 7 and 12 of the trial. In addition, Principal Response Curve analysis was performed to analyse the change in vegetation composition over time and ANOVA for plant species richness in plots. The results showed that over time there were no differences in the odds of finding indicators of any of the three types, for any of the mowing techniques. Furthermore, there were no apparent change in vegetation composition and only a small effect on richness. These results suggest that mowing using a sickle bar mower or a grass trimmer had the same effect on the floristic composition of grasslands, and both techniques can be recommended for use in semi-natural grasslands.
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| 89. |
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| 90. |
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