| 1. |
- Eneslätt, Kjell, et al.
(författare)
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Signatures of T cells as correlates of immunity to Francisella tularensis
- 2012
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3, s. e32367-
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Tidskriftsartikel (refereegranskat)abstract
- Tularemia or vaccination with the live vaccine strain (LVS) of Francisella tularensis confers long-lived cell-mediated immunity. We hypothesized that this immunity depends on polyfunctional memory T cells, i.e., CD4(+) and/or CD8(+) T cells with the capability to simultaneously express several functional markers. Multiparametric flow cytometry, measurement of secreted cytokines, and analysis of lymphocyte proliferation were used to characterize in vitro recall responses of peripheral blood mononuclear cells (PBMC) to killed F. tularensis antigens from the LVS or Schu S4 strains. PBMC responses were compared between individuals who had contracted tularemia, had been vaccinated, or had not been exposed to F. tularensis (naive). Significant differences were detected between either of the immune donor groups and naive individuals for secreted levels of IL-5, IL-6, IL-10, IL-12, IL-13, IFN-gamma, MCP-1, and MIP-1 beta. Expression of IFN-gamma, MIP-1 beta, and CD107a by CD4(+)CD45RO(+) or CD8(+) CD45RO(+) T cells correlated to antigen concentrations. In particular, IFN-gamma and MIP-1 beta strongly discriminated between immune and naive individuals. Only one cytokine, IL-6, discriminated between the two groups of immune individuals. Notably, IL-2- or TNF-alpha-secretion was low. Our results identify functional signatures of T cells that may serve as correlates of immunity and protection against F. tularensis.
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| 2. |
- Gräsvik, John, et al.
(författare)
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Evaluation of four ionic liquids for pretreatment of lignocellulosic biomass.
- 2014
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Ingår i: BMC Biotechnology. - : Springer. - 1472-6750. ; 14:1, s. 34-45
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lignocellulosic biomass is highly recalcitrant and various pretreatment techniques are needed to facilitate its effective enzymatic hydrolysis to produce sugars for further conversion to bio-based chemicals. Ionic liquids (ILs) are of interest in pretreatment because of their potential to dissolve lignocellulosic materials including crystalline cellulose.RESULTS: Four imidazolium-based ionic liquids (ILs) ([C=C2C1im][MeCO2], [C4C1im][MeCO2], [C4C1im][Cl], and [C4C1im][HSO4]) well known for their capability to dissolve lignocellulosic species were synthesized and then used for pretreatment of substrates prior to enzymatic hydrolysis. In order to achieve a broad evaluation, seven cellulosic, hemicellulosic and lignocellulosic substrates, crystalline as well as amorphous, were selected. The lignocellulosic substrates included hybrid aspen and Norway spruce. The monosaccharides in the enzymatic hydrolysate were determined using high-performance anion-exchange chromatography. The best results, as judged by the saccharification efficiency, were achieved with [C4C1im][Cl] for cellulosic substrates and with the acetate-based ILs for hybrid aspen and Norway spruce. After pretreatment with acetate-based ILs, the conversion to glucose of glucan in recalcitrant softwood lignocellulose reached similar levels as obtained with pure crystalline and amorphous cellulosic substrates. IL pretreatment of lignocellulose resulted in sugar yields comparable with that obtained with acidic pretreatment. Heterogeneous dissolution with [C4C1im][HSO4] gave promising results with aspen, the less recalcitrant of the two types of lignocellulose included in the investigation.CONCLUSIONS: The ability of ILs to dissolve lignocellulosic biomass under gentle conditions and with little or no by-product formation contributes to making them highly interesting alternatives for pretreatment in processes where high product yields are of critical importance.
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| 3. |
- Luca, Bogdan, et al.
(författare)
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Clinical and Microbiological Characteristics of Severe Streptococcus pyogenes Disease in Europe.
- 2009
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Ingår i: Journal of Clinical Microbiology. - 1098-660X. ; 47, s. 1155-1165
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to compare the epidemiology of severe S. pyogenes infection within Europe, prospective data were collected through the Strep-EURO programme. Surveillance of severe S. pyogenes infection diagnosed during 2003 and 2004 was undertaken in eleven countries across Europe using a standardised case definition and questionnaire. Patient data as well as bacterial isolates were collected and characterized by T- and, M/emm-typing and selected strains were analysed for presence of superantigen genes. Data were analysed to compare the clinical and microbiological patterns of infections across participating countries. Totally 4353 isolates were collected from 5521 cases with severe S. pyogenes infection identified. It was wide diversity of M/emm-types (104) found among the S. pyogenes clinical isolates but M/emm-type distribution varied broadly between participating countries. The ten most predominant M/emm-types were 1, 28, 3, 89, 87, 12, 4, 83, 81, and 5 in descending order. A correlation was found between some specific disease manifestation, age of patients and emm-types. Streptococcal toxic shock syndrome and necrotizing fasciitis, although caused by a large number of types, were particularly associated with M/emm-types 1 and 3. The emm-types included in the 26-valent vaccine under development, were generally well represented in the presentmaterial; 16 of the vaccine types accounted for 69% of isolates. The Strep-EURO collaborative programme has contributed to enhance the knowledge on the spread of invasive disease caused by S. pyogenes within Europe and encourage future surveillance with notification of cases and characterisation of strains, important for vaccine strategies and other health care issues.
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| 4. |
- Normark, Carl Jörgen, et al.
(författare)
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Evaluation of car instrumentation clusters by using eye-tracking
- 2007
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Ingår i: EAEC 2007 Proceedings. - : EAEC.
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Konferensbidrag (refereegranskat)abstract
- The importance of the ambience presented by instrumentation in the vehicle of today is of great significance for the automotive industry. The rapid technological development of electronic equipment has enabled the large amount of information devices in the drivers' environment. The types of driver information and their appearances are well identified by car manufacturers, but there is a lack of knowledge regarding drivers' perceptions of instrumentation clusters as well as their appearance. To increase this knowledge a study was conducted in order to measure these perceptions. Twenty-three subjects were studied using a method consisting of eye-tracking, assessments and interviews. Each subject was to view eight clusters and to assess each cluster according to six different semantic descriptions. The interviews were based on the subject's individual eye-tracking data. The subject was monitored by an eye-tracking equipment during the assessment task. The results showed that there were some significant correlations between time spent viewing a cluster and its assessment. Moreover, the results also give a view on how clusters are assessed and why they are assessed in particular ways.
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| 5. |
- Normark, Monica, et al.
(författare)
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Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine
- 2014
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Ingår i: BMC Biotechnology. - : BioMed Central (BMC). - 1472-6750. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. Results: All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Conclusions: Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass.
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| 6. |
- Normark, Monica, et al.
(författare)
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Biochemical Conversion of Torrefied Norway Spruce After Pretreatment with Acid or Ionic Liquid
- 2016
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Ingår i: Bioenergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 9:1, s. 355-368
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Tidskriftsartikel (refereegranskat)abstract
- The chemical effects of torrefaction and the possibility to combine torrefaction with biochemical conversion were explored in experiments with five preparations of wood of Norway spruce that had been torrefied using different degrees of severity. Compositional analysis and analyses using solid-state CP/MAS C-13 NMR, Fourier-transform infrared (FTIR) spectroscopy, and Py-GC/MS showed small gradual changes, such as decreased hemicellulosic content and increased Klason lignin value, for torrefaction conditions in the range from 260 A degrees C and 8 min up to 310 A degrees C and 8 min. The most severe torrefaction conditions (310 A degrees C, 25 min) resulted in substantial loss of glucan and further increase of the Klason lignin value, which was attributed to conversion of carbohydrate to pseudo-lignin. Even mild torrefaction conditions led to decreased susceptibility to enzymatic hydrolysis of cellulose, a state which was not changed by pretreatment with sulfuric acid. Pretreatment with the ionic liquid (IL) 1-butyl-3-methylimidazolium acetate overcame the additional recalcitrance caused by torrefaction, and the glucose yields after 72 h of enzymatic hydrolysis of wood torrefied at 260 A degrees C for 8 min and at 285 A degrees C for 16.5 min were as high as that of IL-pretreated non-torrefied spruce wood. Compared to IL-pretreated non-torrefied reference wood, the glucose production rates after 2 h of enzymatic hydrolysis of IL-pretreated wood torrefied at 260 A degrees C for 8 min and at 285 A degrees C for 16.5 min were 63 and 40 % higher, respectively. The findings offer increased understanding of the effects of torrefaction and indicate that mild torrefaction is compatible with biochemical conversion after pretreatment with alternative solvents that disrupt pseudo-lignin-containing lignocellulose.
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| 7. |
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| 8. |
- Normark, Monica, 1980-
(författare)
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Pretreatment and enzymatic saccharification of lignocellulose : formation and effects of pseudolignin
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Production of advanced biofuels, green chemicals, and bio-based materials from renewable lignocellulosic biomass would contribute to decreased dependence on fossil resources and to sustainable development. The overall aim of the investigations was to explore how preprocessing and pretreatment technologies affected the chemical composition of cellulosic materials and their susceptibility to enzymatic saccharification, which is one of the major routes for biorefining of lignocellulose. Special attention was given to formation and effects of pseudolignin, an aromatic substance derived from polysaccharides. Pseudolignin is formed during dry thermal preprocessing, such as torrefaction, and during dilute-acid pretreatment, techniques that are highly relevant for biorefining of wood.The susceptibility of seven fractions of Scots pine to dilute-acid pretreatment and enzymatic saccharification was investigated. Harsh pretreatment conditions led to slow initial conversion, which was tentatively attributed to pseudolignin. Pretreatment with ionic liquids was investigated using substrates consisting of crystalline and amorphous cellulose, hemicelluloses, and wood. The susceptibility of torrefied spruce wood to enzymatic saccharification after pretreatment with acid or ionic liquid was investigated. The results showed that the negative effects of mild torrefaction on enzymatic saccharification were possible to overcome using pretreatment with the ionic liquid. In a subsequent study, the possibility to dissolve pseudolignin with ionic liquids and conventional solvents was explored. The effects of pseudolignin on wood polysaccharides and enzymatic saccharification were further studied using NMR, FTIR, XPS, TOF-SIMS, and SEM. The surface-sensitive analytical methods TOF-SIMS, XPS, and SEM revealed how pseudolignin formed a coat on the surface of the polysaccharide, which could explain the effects on the enzymatic saccharification.
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