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  • 1.
    Abdel-Rehim, Mohamed
    et al.
    Karlstads universitet, Institutionen för kemi.
    Altun, Zeki
    Karlstads universitet, Institutionen för kemi.
    Blomberg, Lars
    Karlstads universitet, Institutionen för kemi.
    Microextraction in packed syringe (MEPS) for liquid and gas chromatographic applications: Part II - Determination of ropivacaine and its metabolites in human plasma samples using MEPS with liquid chromatography/tandem mass spectrometry2004Inngår i: Journal of Mass Spectrometry, ISSN 1076-5174, E-ISSN 1096-9888, Vol. 39, nr 12, s. 1488-1493Artikkel i tidsskrift (Fagfellevurdert)
  • 2.
    Alriksson, Björn
    et al.
    Karlstads universitet, Institutionen för kemi.
    Horváth, Ilona Sárvári
    Karlstads universitet, Institutionen för kemi.
    Sjöde, Anders
    Karlstads universitet, Institutionen för kemi.
    Nilvebrant, Nils-Olof
    Karlstads universitet, Institutionen för kemi.
    Jönsson, Leif J
    Karlstads universitet, Institutionen för kemi.
    Ammonium hydroxide detoxification of spruce acid hydrolysates.2005Inngår i: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 121-124, s. 911-22Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When dilute-acid hydrolysates from spruce are fermented to produce ethanol, detoxification is required to make the hydrolysates fermentable at reasonable rates. Treatment with alkali, usually by overliming, is one of the most efficient approaches. Several nutrients, such as ammonium and phosphate, are added to the hydrolysates prior to fermentation. We investigated the use of NH4OH for simultaneous detoxification and addition of nitrogen source. Treatment with NH4OH compared favorably with Ca(OH)2, Mg(OH)2, Ba(OH)2, and NaOH to improve fermentability using Saccharomyces cerevisiae. Analysis of monosaccharides, furan aldehydes, phenols, and aliphatic acids was performed after the different treatments. The NH4OH treatments, performed at pH 10.0, resulted in a substantial decrease in the concentrations of furfural and hydroxymethylfurfural. Under the conditions studied, NH4OH treatments gave better results than Ca(OH)2 treatments. The addition of an extra nitrogen source in the form of NH4Cl at pH 5.5 did not result in any improvement in fermentability that was comparable to NH4OH treatments at alkaline conditions. The addition of CaCl2 or NH4Cl at pH 5.5 after treatment with NH4OH or Ca(OH)2 resulted in poorer fermentability, and the negative effects were attributed to salt stress. The results strongly suggest that the highly positive effects of NH4OH treatments are owing to chemical conversions rather than stimulation of the yeast cells by ammonium ions during the fermentation.

  • 3.
    Altun, Zeki
    Karlstads universitet, Institutionen för kemi.
    New Techniques for Sample Preparation in Analytical Chemistry2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Sample preparation is often a bottleneck in systems for chemical analysis. The aim of this work was to investigate and develop new techniques to address some of the shortcomings of current sample preparation methods. The goal has been to provide full automation, on-line coupling to detection systems, short sample preparation times and high-throughput.

    A new technique for sample preparation that can be connected on-line to liquid chromatography (LC) and gas chromatography (GC) has been developed. Microextraction in packed syringe (MEPS) is a new solid-phase extraction (SPE) technique that is miniaturized and can be fully automated. In MEPS approximately 1 mg of sorbent material is inserted into a gas tight syringe (100-250 μL) as a plug. Sample preparation takes place on the packed bed. Evaluation of the technique was done by the determination of local anaesthetics in human plasma samples using MEPS on-line with LC and tandem mass spectrometry (MS-MS). MEPS connected to an autosampler was fully automated and clean-up of the samples took one minute. In addition, in the case of plasma samples the same plug of sorbent could be used for about 100 extractions before it was discarded.

    A further aim of this work was to increase sample preparation throughput. To do that disposable pipette tips were packed with a plug of porous polymer monoliths as sample adsorbent and were then used in connection with 96-well plates and LC-MS-MS. When roscovitine in human plasma and water samples was used as model substance, a 96-plate was handled in two minutes.

  • 4.
    Altun, Zeki
    et al.
    Karlstads universitet, Institutionen för kemi.
    Abdel-Rehim, Mohamed
    Karlstads universitet, Institutionen för kemi.
    Blomberg, Lars G.
    Karlstads universitet, Institutionen för kemi.
    New trends in sample preparation: on-line microextraction in packed syringe (MEPS) for LC and GC applications Part III: Determination and validation of local anaesthetics in human plasma samples using a cation-exchange sorbent, and MEPS–LC–MS–MS2004Inngår i: Journal of chromatography. B, ISSN 1570-0232, E-ISSN 1873-376X, Vol. 813, nr 1-2, s. 129-135Artikkel i tidsskrift (Fagfellevurdert)
  • 5.
    Altun, Zeki
    et al.
    Karlstads universitet, Institutionen för kemi.
    Blomberg, Lars G.
    Karlstads universitet, Institutionen för kemi.
    Abdel-Rehim, Mohamed
    Karlstads universitet, Institutionen för kemi.
    Increasing Sample Preparation Throughput Using Monolithic Methacrylate Polymer as Packing Material for 96-Tips: 2 Minutes per 96-Well Plate2005Manuskript (preprint) (Annet vitenskapelig)
  • 6.
    Andersson, Magnus S.
    Karlstads universitet, Institutionen för kemi.
    Capillary electrophoresis methods for the separation of the basic compound lidocaine and its metabolites2003Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    For the separation of the basic compound lidocaine and its metabolites a variety of capillary electrophoresis (CE) methods have been developed. This includes capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC) and nonaqueous CE separations. The parameters affecting the separations were investigated and optimized.

    In CZE reproducible separations were obtained in both un-coated and polyacrylamide-coated fused silica capillaries using a TFA/TEA electrolyte at pH 2.5.

    The MEKC method: a low pH phosphate/Tris buffer containing the cationic surfactant cetyltrimethylammonium bromide (CTAB) was successfully validated in human plasma.

    A couple of nonaqueous methods were developed. One of the methods 70 mM ammonium formate and 2 M formic acid in acetonitrile/methanol (60:40 v/v) was used for capillary electrophoresis-electrospray mass spectrometry analysis. Reproducible determinations in human plasma were obtained. The sensitivity was improved compared to UV. The detection limits for lidocaine and the metabolites monoethylglycinexylidide (MEGX) and glycinexylidide (GX) were 69 nM, 130 nM and 337 nM respectively. Parameters such as sheath liquid composition, nebulizing gas pressure and drying gas temperature were considered.

    The results show that CE is a simple and powerful technique for the separation of basic compounds.

  • 7.
    Bergeld, Linnéa
    Karlstads universitet, Institutionen för kemi.
    Trametes versicolor laccase: random mutagenesis and heterologous expression in Pichia pastoris2008Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    Laccase is a blue multi-copper oxidase. It has a broad biotechnical potential which increases the interest to study the enzyme further. A laccase-encoding gene from the white-rot fungus Trametes versicolor (lcc2) was mutated using two different methods for random mutagenesis: error-prone PCR and a method based on an E.coli strain (ES1301 mutS) that introduces random mutations. For the error-prone PCR reaction, the vector pPICZB with the lcc2 gene inserted was used as template. The E. coli strain ES1301 mutS was transformed with the vector pBluescript SKII with the lcc2 gene as insert. The mutagenesis products were cloned into the Pichia pastoris expression vector pPICZB for transformation of P. pastoris SMD1168. The transformants were spread on agar plates containing zeocin. Laccase-secreting transformants were selected by their ability to oxidize the substrates ABTS [2,2´-azinobis-(3-ethylbenzthiazoline-6-sulfonic acid)] and syringaldazine [N,N´-bis(3,5-dimethoxy-4-hydroxybenzylidene)hydrazine], the products of which give green and purple colour, respectively. Around 20 transformants from each of the mutagenesis methods were transformed to plates containing 1 mM ABTS or 1 mM syringaldazine. None of the transformants produced any colour. Control transformants (pPICZB with unmutated lcc2) were also spread on plates with either ABTS or syringaldazine. The transformants gave rise to green colour after 24 hours on the ABTS plates and to purple colour after 72 hours on the syringaldazine plates. Experimets with different chromogenic substrates indicated that ABTS and syringaldazine were best suited for screening of mutants. Remazol Brilliant Blue and Phenol Red are two substrates that after optimisation can serve as alternatives for the selection of laccase-secreting transformants.

  • 8.
    Bergendahl, Rikard
    Karlstads universitet, Institutionen för kemi.
    Felkällor och systematiska avvikelser i kvalitetsuppföljningen av tidnings- och journalpapper2008Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [sv]

    I papperstillverkning ställs det krav inte bara på kvalité och kvantitet utan också att stickprov från produktion utförs och tas hand om på ett korrekt sätt. Från det att ett stickprov tas ut och undersöks på brukets laboratorium kan en del källor till förändringar på provresultatet uppstå. Sådana förändringar kan uppstå för det första vid hanteringen av stickprov från pappersmaskin och provens transportering till laboratoriet och för det andra vid laboratoriets hantering och uppföljning av kvalitén. En annan faktor som kan påverka stickproven är klimatet. Årstiderna vår och höst är de tider som proverna kan påverkas mest. Prover undersöks med jämna mellanrum från färdigt papper och används till kalibrering av on-line mätning på pappersmaskin. Vissa av provresultaten skickas direkt till kunden i form av ett analyscertifikat.

    I detta examensarbete var syftet att analysera vissa felkällor i provhanteringen och vad klimatet hade för påverkan på provresultatet. Det undersöktes hur varierande klimatförhållanden på pappersmaskin kunde påverka provresultaten för prov som undersöktes direkt på laboratoriet. Resultat från de proven har sen jämförts med prov som konditionerades en tid på laboratoriet i ett fast klimat (23°C, 50 % RH). Prov konditionerades både efter att provet tagits ut direkt och efter att provet hade legat uppe i maskinhallen under en längre tid. I arbetet ingick det att årstider skulle simuleras och det utfördes på Stora Enso Research Center i Falun i ett speciellt klimatrum. Klimaten som papper undersöktes i då var extremt torrt och extremt fuktigt och dessa resultat jämfördes med resultat från normalt provtagningsklimat.

    Papperskvalitéerna som undersöktes var 45 g/m2 standard tidningspapper från PM 11 och 52 g/m2 SC-papper (obestruket journalpapper) från Kvarnsvedens nya maskin PM 12. Det som undersöktes var de kritiska parametrarna där det föreligger risk för att papper måste kasseras. De kritiska egenskaperna som har kassaktionsgräns är ytvikt, ljushet, nyans och i även vissa fall ytråhet och rivstyrka.

    Resultaten visade att vid extrema klimatförhållanden från undersökningen på Stora Enso Research Center hade många prover påverkats till den grad att de hade lett till kassaktion. För SC-papper var ytråheten den egenskap som var mest kritisk vid extremt torrt klimat och vid fuktigt klimat var ytvikt den mest känsliga egenskapen. För standard tidningspapper var ytvikt och rivstyrka de egenskaper som påverkades mest av extremt klimat och pappret hade fått kasseras vid både extremt torrt och fuktigt klimat.

    Vid undersökningen på Kvarnsveden visade resultaten att fukthalten i pappret påverkades mer än vad papprets övriga egenskaper gjorde. Förändringarna i papprets övriga egenskaper var endast marginella och höll sig inom respektive gränsvärde för kassaktion. Nyans och de andra optiska egenskaperna hade marginella förändringar för både varierande och extrema klimatförhållanden och förändringarna kan i de flesta fall anses försumbara för produktionen.

    I de fall där det råder extrema klimatförhållanden som det kan göra vid vissa årstider är det mycket viktigt att operatörens hantering av stickprov sker på ett korrekt sätt. Då gäller det att stickproverna skickas ner till laboratoriet så snabbt som möjligt där påverkan är mindre än vad den kan vara inne i maskinhallen.

  • 9.
    Bergman, Helene
    et al.
    Karlstads universitet, Institutionen för kemi.
    Gillstedt, Anna
    Karlstads universitet, Institutionen för kemi.
    Tungmetallbalans över Gruvöns bruk2002Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
  • 10.
    Bohlin, Maria E.
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap. Karlstads universitet, Institutionen för kemi.
    Capillary electrophoresis of β2-glycoprotein I2006Licentiatavhandling, med artikler (Annet vitenskapelig)
  • 11.
    Bohlin, Maria E.
    et al.
    Karlstads universitet, Institutionen för kemi.
    Blomberg, Lars G.
    Karlstads universitet, Institutionen för kemi.
    Heegard, Niels H.H.
    Department of Autoimmunology, Statens Serum Institut, Copenhagen.
    Utilizing the pH hysteresis effect for versatile and simple electrophoretic analysis of protein in bare fused-silica capillaries2005Inngår i: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 26, nr 21, s. 4043-4049Artikkel i tidsskrift (Fagfellevurdert)
  • 12.
    Bohlin, Maria E.
    et al.
    Karlstads universitet, Institutionen för kemi.
    Kogutowska, Ewa
    Department of Autoimmunology, Statens Serum Institut, Copenhagen.
    Blomberg, Lars G.
    Karlstads universitet, Institutionen för kemi.
    Heegaard, Niels H.H.
    Department of Autoimmunology, Statens Serum Institut, Copenhagen.
    Capillary electrophoresis-based analysis of phospholipid and glycosaminoglycan binding by human β2-glycoprotein I2004Inngår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1059, s. 215-222Artikkel i tidsskrift (Fagfellevurdert)
  • 13.
    Carlsson, Gunilla
    Karlstads universitet, Institutionen för kemi.
    Latex Colloid Dynamics in Complex Dispersions: Fluorescence Microscopy Applied to Coating Color Model Systems2004Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Coating colors are applied to the base paper in order to maximize the performance of the end product. Coating colors are complex colloidal systems, mainly consisting of water, binders, and pigments. To understand the behavior of colloidal suspensions, an understanding of the interactions between its components is essential.

  • 14.
    Carlsson, Gunilla
    et al.
    Karlstads universitet, Institutionen för kemi.
    Järnström, Lars
    Karlstads universitet, Institutionen för kemi.
    van Stam, Jan
    Karlstads universitet, Institutionen för kemi.
    Latex Diffusion at High Volume Fractions Studied by Fluorescence Microscopy2006Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 298, nr 1, s. 162-171Artikkel i tidsskrift (Fagfellevurdert)
  • 15.
    Carlsson, Gunilla
    et al.
    Karlstads universitet, Institutionen för kemi.
    van Stam, Jan
    Karlstads universitet, Institutionen för kemi.
    Interactions between Charged Latex Colloids and Starch Polyelectrolytes Studied with Fluorescence  Microscopy with Image Analysis2005Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 20, nr 2, s. 192-199Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The interactions between carboxylated polystyrene latex probe particles and ionically substituted starches have been investi-gated by fluorescence microscopy with image analysis. The degree of substitution of the starches was varied, as was also thepolyelectrolyte molecular weight and the probe size. 

  • 16.
    Carlsson, Gunilla
    et al.
    Karlstads universitet, Institutionen för kemi.
    van Stam, Jan
    Karlstads universitet, Institutionen för kemi.
    Latex Film Formation Studied with Fluorecence MicroscopyManuskript (Annet (populærvitenskap, debatt, mm))
  • 17.
    Carlsson, Gunilla
    et al.
    Karlstads universitet, Institutionen för kemi.
    Warszynski, Piotr
    van Stam, Jan
    Karlstads universitet, Institutionen för kemi.
    Dynamic Fluorescence Microscopy As a Feasible Technique for Estimating the Diffusion Coefficients of Small Particles in the Presence of Additives2003Inngår i: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 267, nr 2, s. 500-508Artikkel i tidsskrift (Fagfellevurdert)
  • 18.
    Danielsson, Fredrik
    Karlstads universitet, Institutionen för kemi.
    Optimering av blekeriet i CTMP-linjen vid Rottneros Bruk2006Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    At Rottneros pulp mill mechanical pulp is bleached with hydrogen peroxide. The changes of bleaching chemicals that are used for different grades are taken from bleaching tables; however these tables are old and need to be updated. The purpose of this thesis was to be the basis of new documentation.

    In this thesis three pulps where studied with the aim to find the optimal bleaching chemical changes (total NaOH/VP-quote) for each pulp. The pulps were taken from the filter before the bleaching tower and the pulps were bleached in the lab. The most important pulp property in this study was the brightness and how that was influenced by the chemical dosages. A fiberline inspection was also done to examine the brightness gain during the process. Finally a study was carried out to examine how freeness affected the brightness for low- and high freeness pulps.

    The studies showed that reduced chemical consumption was possible to achieve for all pulps studied. For pulp CA 683 a total NaOH/VP-ratio of 0,8 was suggested, while the ratio were 1,1 for CA 970 and 0,7 for CS 770.

    Lower freeness increased the brightening of the pulp at the same chemical consumption.

  • 19.
    Danielsson Thorell, Helena
    et al.
    Karlstads universitet, Institutionen för kemi.
    Karlsson, Jan
    Karlstads universitet, Institutionen för kemi.
    Portelius, Erik
    Karlstads universitet, Institutionen för kemi.
    Nilsson, Thomas
    Karlstads universitet, Institutionen för kemi.
    Cloning, characterisation, and expression of a novel gene encoding chlorite dismutase from Ideonella dechloratans2002Inngår i: Biochimica et Biophysica Acta, Gene Structure and Expression, ISSN 0167-4781, E-ISSN 1879-2634, Vol. 1577, nr 1, s. 445-451Artikkel i tidsskrift (Fagfellevurdert)
  • 20.
    Danielsson Thorell, Helena
    et al.
    Karlstads universitet, Institutionen för kemi.
    Stenklo, Katarina
    Karlstads universitet, Institutionen för kemi.
    Karlsson, Jan
    Karlstads universitet, Institutionen för kemi.
    Nilsson, Thomas
    Karlstads universitet, Institutionen för kemi.
    A Gene Cluster for Chlorate Metabolism in Ideonella dechloratans2003Inngår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 69, nr 9, s. 5585-5592Artikkel i tidsskrift (Fagfellevurdert)
  • 21.
    Eriksson, Björn
    Karlstads universitet, Institutionen för kemi.
    In-line application of electric fields in capillary separation systems2006Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The magnitude of an electric field possible to apply in a capillary separation system is limited, because a high electric field causes a too high current through the capillary. Application of the electric field in-line will give an increased conductivity in the column, further increasing the risk of too high currents. The conductivity changes were found to result from an overall increase in ionic strength within the electric field. The increase in ionic strength is caused by the increase in mobile phase ions with electrophoretic velocity against the flow, together with OH- or H3O+ ions (depending on polarity) formed at the inlet electrode. Further it was found that the use of a pressurized reservoir or splitting of the flow at the inlet electrode could significantly limit the conductivity changes and thereby the maximum applicable electric field strengths could be increased.

  • 22.
    Eriksson, Björn
    et al.
    Karlstads universitet, Institutionen för kemi.
    Andersson, Magnus
    Department of Analytical Chemistry, Pharmaceutical and Analytical Research and Development, AstraZeneca AB, Sweden.
    Blomberg, Lars
    Karlstads universitet, Institutionen för kemi.
    Deviation from Ohm’s law in electric field assisted capillary LC2003Inngår i: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1010, nr 1, s. 17-24Artikkel i tidsskrift (Fagfellevurdert)
  • 23.
    Erlandsson, Ann
    Karlstads universitet, Institutionen för kemi.
    Idiotypic and antiidiotypic antibodies, Oral presentation2005Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 24.
    Erlandsson, Ann
    et al.
    Karlstads universitet, Institutionen för kemi.
    Holm, Patrik
    Karlstads universitet, Institutionen för kemi.
    Ullén, Amanda
    Department of Immunology, Umeå University.
    Stigbrand, Torgny
    Department of Immunology, Umeå University.
    Sundström, Birgitta E.
    Karlstads universitet, Institutionen för kemi.
    Studies of the interactions between the anticytokeratin 8 monoclonal antibody TS1, its antigen and its anti-idiotypic antibody αTS12003Inngår i: Journal of Molecular Recognition, ISSN 0952-3499, E-ISSN 1099-1352, Vol. 16, nr 3, s. 157-163Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The monoclonal antibody TS1 against cytokeratin 8 and its antiidiotype αTS1 have been used for immunotargeting and therapy of carcinomas in experimental tumor model systems. The interaction surfaces between mab TS1, the cytokeratin 8 epitope, and its anti-idiotypic antibody, αTS1, were studied in detail in order to make future veneering of the interactions possible. The V-genes of TS1 and αTS1 were cloned and sequenced and the CDRs and the framework residues were identified. Amino acids participating in the interactions were identified following chemical modifications of residues in non-protected and protected molecules of cytokeratin 8, αTS1 and TS1. From the sequences, the three-dimensional structures were generated using computer modelling of the antibody variable regions. Several charged amino acid, histidine and tyrosine residues were displayed in the antibody surfaces implicated in the interactions and chemical modification confirmed the importance of these amino acids. The cytokeratin 8 epitope has previously been identified by Johansson et al. and it displays negatively charged amino acid residues which could be identified in the chemical modification. It was also revealed that the TS1 binding to cytokeratin 8 and αTS1 respectively are partly overlapping; a histidine identified in TS1 is probably involved only in the interaction with αTS1. Furthermore, the chemical modification demonstrated that exchanging aspartic–glutamic acids to asparagine–glutamine residues in TS1 increased the binding of TS1 to cytokeratin 8, indicating that there is at least one acidic amino acid that is an obstacle in the TS1–CK8 binding. The detailed assembly of the interaction surfaces will facilitate the future use of site directed mutagenesis to improve the TS1–CK8 association rate and the clearing of TS1 with αTS1 in vivo.

  • 25.
    Forshult, Stig E.
    Karlstads universitet, Institutionen för kemi.
    Quantitative analysis with pulsed NMR and the CONTIN computer program2004Rapport (Annet vitenskapelig)
    Abstract [en]

    Various substances have been analyzed by pulsed NMR at 0.47 T in order to extract quantitative information from the CPMG spin-echo signal. This signal can be considered to show the true T2 relaxation of the analyte/s. In most cases the relaxation is a first order process and the FID will be a sum of several exponentially decreasing signals. This can be resolved into its components by an inverse Laplace transform. To achieve this the CONTIN computer program has been our tool. The result is a spectrum-like graph with the peaks of the individual FIDs as functions of the time constants T2. By calculating the peak areas and divide them with the T2 of the peaks one can find the total number of protons relaxing in a T2-range. This may also bee done by drawing the graph with a logarithmic abscissa. Then the peak areas, now integrals of f(T2) with respect to lg T2, will directly show the relative amounts of protons at each T2 The spectrum will also be better resolved over a broader range of various relaxation times. However, as the peaks are assumed to have Gaussian shapes, they will be slightly distorted on a logarithmic abscissa.

    Thus, with an inverse Laplace transform it is possible to make calculations of the relative amount of protons in a sample without any chemical pretreatment. The result is not a full analysis of the sample but can be regarded as a characterization of its main components.

  • 26.
    Fredriksson, Lars
    Karlstads universitet, Institutionen för kemi.
    A Brief Survey of Lévy Walks: with applications to probe diffusion2010Independent thesis Basic level (degree of Bachelor), 15 poäng / 22,5 hpOppgave
    Abstract [en]

    Lévy flights and Lévy walks are two mathematical models used to describe anomalous diffusion(i.e. those having mean square displacements nonlinearly related to time (as opposed to Brownian motion)). Lévy flights follow probability distributions p(|r|) yielding infinite mean square displacements since some rare steps are very long. Lévy walks, however, have coupled space-time probability distributions penalising very long steps. Both Lévy flights and Lévy walks are dominated by a few long steps, but most steps are much, much smaller. The semi-experimental part ofthis work dealt with how fluorescent probes moved in systems of cationic starch and latex/solutions of dodecyl trimethyl ammonium bromide, respectively. Visually, no Lévy walks couldbe detected. However, mathematical regression suggested enhanced diffusion and subdiffusion. Moreover, time-dependent diffusion coefficients were calculated. Also examined was how Microsoft Excel could be used to generate normal diffusion as well as anomalous diffusion.

  • 27.
    Holm, Patrik
    Karlstads universitet, Institutionen för kemi.
    Single-chain antibody construction and functional mapping of the monoclonal antibody TS1: Its interaction with the antigen and the anti-idiotype2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The aims of this study are to synthesize and produce a single-chain antibody (scFv) of the anti-cytokeratin 8 monoclonal IgG antibody TS1 and to functionally map amino acid residues important for the interaction with its antigen and the anti-idiotypic antibody TS1. The TS1 antibody has been shown to be effective in binding cytokeratin 8 (CK8) expressed in tumors in vivo and is proposed to be useful in immunotargeting and/or immunotherapy. The anti-idiotypic antibody TS1 can be used to regulate the tumor:non-tumor ratio. Mutagenesis of certain amino acid residues can be used to alter the affinity to improve the tumor:non-tumor ratio further.

    In the present study, the TS1 IgG was chemically modified to specify groups of residues important for interaction with both CK8 and TS1. If important residues were found in the CDRs, they were mutated in the TS1 scFv construct and the effect was studied using ELISA.

    The main conclusions drawn from this study are that the important amino acid residues in TS1 for the interaction with both CK8 and TS1 are mainly tyrosines, charged residues and a tryptophan. A central interacting interface was identified with the somewhat unusual participation of residues in the CDR 2 of the light chain. Mutations which resulted in increased affinity to both CK8 and TS1 were also identified.

  • 28.
    Holm, Patrik
    et al.
    Karlstads universitet, Institutionen för kemi.
    Jafari, Rozbeh
    Erlandsson, Ann
    Stigbrand, Torgny
    Functional Mapping and Single Chain Construction of the Anti-Cytokeratin 8 Monoclonal Antibody TS1Manuskript (Annet (populærvitenskap, debatt, mm))
  • 29.
    Hong, Feng
    et al.
    Institute of Biological Sciences and Biotechnology, Donghua University, Shanghai.
    Sjöde, Anders
    Karlstads universitet, Institutionen för kemi.
    Nilvebrant, Nils-Olof
    STFI-Packforsk AB, Swedish Pulp and Paper Research Institute, Stockholm, Sweden.
    Jönsson, Leif J.
    Karlstads universitet, Institutionen för kemi.
    Enzymatic method for rapid determination of oxalic acid in bleaching filtrates from the pulp and paper Industry2005Inngår i: Journal of Donghua University, Vol. 22, s. 64-68Artikkel i tidsskrift (Fagfellevurdert)
  • 30.
    Horváth, Ilona Sárvári
    et al.
    Karlstads universitet, Institutionen för kemi.
    Sjöde, Anders
    Karlstads universitet, Institutionen för kemi.
    Alriksson, Björn
    Karlstads universitet, Institutionen för kemi.
    Jönsson, Leif J
    Karlstads universitet, Institutionen för kemi.
    Nilvebrant, Nils-Olof
    Karlstads universitet, Institutionen för kemi.
    Critical conditions for improved fermentability during overliming of acid hydrolysates from spruce.2005Inngår i: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 121-124, s. 1031-44Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bioethanol can be produced from wood via acid hydrolysis, but detoxification is needed to achieve good fermentability. Overliming was investigated in a factorial designed experiment, in which pH and temperature were varied. Degradation of inhibitory furan aldehydes was more extensive compared to monosaccharides. Too harsh conditions led to massive degradation of sugars and formation of inhibiting acids and phenols. The ethanol productivity and yield after optimal overliming reached levels exceeding reference fermentations of pure glucose. A novel metric, the balanced ethanol yield, which takes both ethanol production and losses of fermentable sugars into account, was introduced and showed the optimal conditions within the investigated range. The findings allow process technical and economical considerations to govern the choice of conditions for overliming.

  • 31.
    Jardeby, Kristina
    et al.
    Karlstads universitet, Institutionen för kemi.
    Germgård, Ulf
    Karlstads universitet, Institutionen för kemi.
    Kreutz, Björn
    Heinze, Thomas
    Heinze, Ute
    Lennholm, Helena
    Effect of pulp properties on the characteristics of undissolved residuals in CMC-solutionsManuskript (preprint) (Annet vitenskapelig)
  • 32.
    Jonsson, Ann-Sofie
    Karlstads universitet, Institutionen för kemi.
    Development and Validation of a Liquid Chromatography-Tandem Mass Spectrometry Method for Determination of Cyclosporine A in Whole Blood2009Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Cyklosporin A (CsA) är en cyklisk polypeptid med molekylvikten är 1202.6 Da. Substansen har svampursprung (Tolypocladium inflatum Gams) och starka immunhämmande egenskaper. CsA används därför som immunsuppressivt läkemedel för att förhindra avstötning av transplanterade organ och benmärg, samt vid behandling av graft-versus-host-disease (transplantat-mot-värd-sjukdom). CsA har ett snävt terapeutiskt fönster, vilket betyder att skillnaden mellan effektivitet och toxicitet är liten. Biverkningarna av substansen är många och en del av dem allvarliga, såsom nedsatt njurfunktion och ökad risk för utvecklande av diabetes och maligna sjukdomar som exempelvis lymfom. Den inter- och intraindividuella variabiliteten i farmakokinetik och farmakodynamik är dessutom stor. Det är därför ytterst viktigt att följa behandlingen med koncentrationsbestämningar av CsA i helblod.

    Det finns ett flertal olika analysmetoder för CsA tillgängliga, såsom immunoassays, vätskekromatografi (HPLC) och vätskekromatografi-tandem-massspektrometri (LC-MS/MS). Avdelningen för klinisk kemi vid Centralsjukhuset i Karlstad har sedan många år använt en radioimmunoassay, CYCLO-Trac SP®, från DiaSorin för att bestämma CsA i helblod. Laboratoriets önskan är att ersätta denna metod, vilken använder radioaktiva isotoper, med en snabbare och mer selektiv LC-MS/MS-metod. 

    I detta arbete har en LC-MS/MS-metod för analys av cyklosporin A i helblod utvecklats och validerats. Metoden har snabb provupparbetning och kromatografi och använder positiv elektrospray som joniseringsteknik. Två procedurer för proteinfällning utvärderades som provupparbetningsförfarande under metodutvecklingen och två olika internstandarder testades; CsA analogen cyklosporin D och isotopmärkt CsA (d12-CsA). 

    Efter den fullständiga valideringen infördes metoden i rutinarbetet 2009-11-01. Resultat från både LC-MS/MS och den radioimmunologiska metoden lämnas ut parallellt under minst fem månader.

  • 33.
    Karlsson, Jan
    et al.
    Karlstads universitet, Institutionen för kemi.
    Nilsson, Thomas
    Karlstads universitet, Institutionen för kemi.
    The C subunit of Ideonella dechloratans chlorate reductase: Expression, purification, refolding, and heme reconstitution2005Inngår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 41, nr 2, s. 306-312Artikkel i tidsskrift (Fagfellevurdert)
  • 34.
    Kindlund, Sören
    et al.
    Karlstads universitet, Institutionen för kemi.
    Schulstad, Johan
    Karlstads universitet, Institutionen för kemi.
    Modellering och styrning av tvåstegs syrgasdelignifiering på Gruvöns Bruk2001Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
  • 35.
    Kjellgren, Henrik
    Karlstads universitet, Institutionen för kemi.
    Barrier properties of greaseproof paper2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The barrier properties of greaseproof paper are achieved by extensive beating of the fibres. This treatment results in high costs for energy, both as beating energy and drying energy. A full-scale trial has been performed to investigate the role of the pulp with respect to energy demand and the barrier properties of the final papers. The paper made of 100% sulphite pulp with a low degree of beating showed the lowest energy consumption at a given level of barrier properties such as air permeance, grease resistance and water vapour transmission rate.

    The papers produced in the full-scale trial have been used as substrates for coating. Greaseproof paper has a closed surface and should therefore be a good base paper for barrier coatings.

    Chitosan has been used as a barrier coating because of its good oxygen barrier properties. Moreover, chitosan is a renewable material. Coating trials on a bench-scale showed that greaseproof paper can be upgraded to provide a good oxygen barrier. The oxygen barrier could not be achieved on a pilot-scale using the metered size press technique, because of the low coat weight applied.

    The influence of the base paper on the barrier properties of chitosan-coated paper has been investigated. It was found that greaseproof paper is better than a paper with a higher porosity. The coating seemed to stay more on the surface of the greaseproof papers and to form a continuous coating layer with better barrier properties.

  • 36.
    Land, Cecilia
    Karlstads universitet, Institutionen för kemi.
    Laboratory method for the study of moisture-induced waviness in paper2004Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Paper that is subjected to moisture undergoes dimensional changes. It expands during moistening and shrinks during drying. When the paper is under tension between rollers, the effects are complex since shrinkage and expansion are restricted in the width direction. Waves can then appear on the paper web. This can be a problem in heatset web offset printing. The problem is known as waviness or fluting. The printed papers exhibit a wavy shape, which is visually disturbing due to light reflections which create glossy streaks. The aim of the work described in this thesis was to develop a method suitable for studying the moisture- and tension-induced waviness. Experiments were carried out on a laboratory scale to study how such waves develop during moistening and drying. The experimental setup was based on a modified tensile tester. A CCD camera and image analysis based on the STFI-OptiTopo technique was used to characterise the waviness. Moistening and drying were achieved by changing the surrounding air humidity. The method was used to study the effect of moisture uptake by the paper, and to evaluate the effect of tension on the waviness. It was found that increasing moisture resulted in a higher waviness amplitude, but that the web tension controlled the wavelength of the waviness. A high tension gave rise to a shorter wavelength. The measured wavelength was compared with a previously suggested model and the predicted wavelength was about twice as high as the measured wavelength.

  • 37.
    Lanzer, Therese
    Karlstads universitet, Institutionen för kemi.
    Ytspänningens inverkan på klisterfogsstyrkan hos Frövi light kartong2005Independent thesis Advanced level (degree of Master (One Year)), 10 poäng / 15 hpOppgave
  • 38.
    Larsson, Johan
    et al.
    Karlstads universitet, Institutionen för kemi.
    Sonemalm, Annica
    Karlstads universitet, Institutionen för kemi.
    Förändring av pappersegenskaper vid lagring under dragspänning2006Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Sammanfattning

    I en pappersrulle är de yttre lagren utsatta för dragspänning. Om det finns variationer i rullens diameter i form av valkar finns det risk för att papperet förlängs irreversibelt i dessa positioner och orsaka slappa stråk. Den deformation som uppstår vid långvarig belastning av papper kallas krypning.

    Uppgiften i detta arbete var, att på lab., simulera valkar genom att utsätta pappersremsor för konstant dragspänning av olika storlekar. En av frågeställningarna var om egenskapsförändringar kan påvisas när papper utsätts för konstant inspänningskraft under en längre tid. De parametrar som undersökts var töjning, kryphastighet och relaxation, även mätningar på papperets mekaniska egenskaper dragstyrka, brottöjning och dragstyvhet har utförts i detta arbete.

    De papperskvalitéer som undersöktes var 71g/m2 MG-papper, 80g/m2 optisk liner och 135g/m2 liner. Inspänningskraften som papperet utsattes för motsvarade 10 %, 30 % och 50 % av dragstyrkan hos varje kvalité. Provremsor belastades under ett, fyra och sju dygn, för att sedan relaxeras.

    Resultaten visar att dragstyrkan och dragstyvheten inte påverkas av att papperet varit utsatt för en inspänningskraft. Däremot blev brottöjningen mindre ju större den irreversibla förlängningen hos papperet var. Samtliga papperskvalitéer relaxerar tillbaka till ursprungslängd efter fyra dygn när belastningen var 10 %. Om belastningen däremot var 30 % och 50 % uppstod en irreversibel förlängning redan efter ett dygn. Vid belastning under sju dygn uppstod permanent förlängning hos samtliga kvalitéer och belastningar utom MG-papper 10 % som relaxerade till ursprungslängd. MG-papper är därmed den papperskvalité som står emot krypning bäst och är på så sätt minst känslig för valkar i pappersrullen.

    En högre belastning ger en högre kryphastighet och större irreversibel förlängning. För att undvika uppkomsten av slappa stråk bör därför banspänningen som används vid upprullningen av papperet inte vara större än 10 % av dragstyrkan hos papperskvalitén.

    Hur länge papperet är belastat påverkar också den slutliga irreversibla förlängningen. Det innebär att lagring ökar risken för att slappa stråk kommer att uppstå i efterbearbetningen.

  • 39.
    Lauth, Angelica
    Karlstads universitet, Institutionen för kemi.
    Rivning av cellsal Akzo Nobel: Risker och möjligheter2008Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [sv]

    På uppdrag av Hifab Byggprojektledaren AB:s (Hifab AB) filial i Karlstad kommer riskerna för spridning av miljöstörande avfall såsom asbest, dioxin, kvicksilver samt PCB att inventeras och utvärderas vid rivning av kemisk industrienhet vid Akzo Nobels anläggning i Skoghall.

    Inventeringen begränsas till att omfatta den gamla kloralkalifabriken byggd 1938-1946 innehållande cellsalar, likriktarutrymmen samt personaldelar.

    Riktad provtagning bygger på tidigare erfarenheter och kunskaper av liknande objekt. Byggnationsår kan ge indikationer på vilka ämnen som kan misstänkas finnas i ev. byggnad då vissa material användes under olika epoker. Metoden är ekonomiskt fördelaktig men ger inte en heltäckande bild över hur föroreningen är spridd.

    Vid riskanalysen är den så kallade MIFO-modellen använd, där bedömning sker från tillgänglig data från den riktade provtagningen.

    Efter genomgången gasskyddsutbildning gavs möjlighet att okulärbesikta gamla cellsalarna med tillhörande personalutrymmen, förråd samt transformator- och likriktarutrymmen. Prover togs för senare analys av asbest och övrig provtagning gällande kvicksilver på platsen är daterade 1999 av Envipro.

    Analysresultaten påvisade ingen asbest i proverna. Enligt uppgift från ansvarig personal på Akzo Nobel har tidigare PCB-prover visat sig vara negativa. Dock har stora mängder kvicksilver påträffats i objektet.

    Slutsatsen är att i cellsalen har halter som överstiger Naturvårdsverkets gränsvärden gällande mindre känslig markanvändning av kvicksilver uppmätts.

    Detta är ett stort miljöproblem som måste åtgärdas så fort som möjligt.

  • 40.
    Mørk, Cato
    et al.
    Department of Dermatology, Rikshospitalet University Hospital, Norway.
    Salerud, E Göran
    Department of Biomedical Engineering, Linköping University.
    Asker, Claes L
    Karlstads universitet, Institutionen för kemi.
    Kvernebo, Knut
    Department of Cardiothoracic Surgery, Ullevaal University Hospital, Norway.
    The Prostaglandin E1 Analog Misoprostol Reduces Symptoms and Microvascular Arteriovenous Shunting in Erythromelalgia: A Double-Blind, Crossover, Placebo-Compared Study2004Inngår i: Journal of Investigative Dermatology, ISSN 0022-202X, E-ISSN 1523-1747, Vol. 122, nr 3, s. 587-593Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Based on previous experience with parenteral prostanoids, we studied the effect of misoprostol treatment, an orally administered prostaglandin E1 analog, in patients with erythromelalgia. Treatment with placebo was followed by treatment with misoprostol (0.4–0.8 mg per d), both for 6 wk. The patients (n=21) and a study nurse who administered the trial were blinded. The endpoints were change in pain and need for cooling and global assessment of the treatment. Following central body heat provocation, global skin perfusion, capillary morphology, and change in pain were also recorded before and after each treatment period. Results were compared with data from healthy control subjects (n=11) that did not undergo treatment. Clinical safety and tolerability evaluation included physical examinations, clinical laboratory tests, and monitoring of adverse events. All clinical outcome measures were significantly better after treatment with misoprostol (p<0.01) as compared with placebo treatment and after a 3-mo follow-up without treatment. The heat-induced increase in global perfusion after misoprostol treatment was similar to the control group and significantly lower when compared with baseline (p<0.01) and placebo treatment (p<0.05), respectively. This study demonstrates that misoprostol is clinically superior to placebo in patients with erythromelalgia. The results of the perfusion studies may imply that the mechanism of action of the beneficial effect of misoprostol is reduced microvascular arteriovenous shunting in affected skin.

  • 41.
    Piercecchi, Marco
    Karlstads universitet, Institutionen för kemi.
    Undersökning av affinitet till TS1-218, TS1-2182 och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider cytokeratin 8 för TS1-218, TS1-2182 och HE1-Q enkelkedjeantikroppar i multicellulära tumörsfäroider2009Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    In vitro-test för upptäckt och behandling av tumör eller mikrometastaser har de senaste 30 åren gjort stora framsteg tack vare immunokemi och nya framgångsrika cellodlings- tekniker som bättre reproducerar celltillväxt i tre dimensioner (3D) och det omgivande stromat (multicellulär tumörsfäroidodling). TS1-218 scFv (single chain variable fragment) är en monoklonal antikropp som har affinitet till ett protein tillhörande cytoskelettet (cytokeratin). Av TS1-218 har skapats olika varianter (en dimer TS1-2182 och en mutant HE1-Q) med syftet att öka affinitet och retentionstid på platsen för dess verkan. I det här projektet försökte vi att testa och jämföra egenskaper hos alla 3 joderade antikropparna genom att inkubera odlade Hela Hep 2 tumörcellssfäroider med dessa antikroppar. Alla tre antikroppsvarianter visade god förmåga att penetrera sfäroider och att binda deras epitop i cytokeratin 8. Försöken visade att det fanns affinitetsskillnader mellan TS1-218 monomer, dimer och mutant vilket visade sig som olika inbindningsförmåga till sfäroiderna.

  • 42.
    Rova, Maria
    et al.
    Karlstads universitet, Institutionen för kemi.
    Mc Ewen, Birgitta
    Karlstads universitet, Institutionen för natur och miljö.
    Fredriksson, Per-Olof
    Karlstads universitet, Institutionen för kemi.
    Styring, Stenbjörn
    Section of Chemistry, Uppsala University, Uppsala.
    Photoactivation and photoinhibition of photosystem II in a mutant of Chlamydomonas reinhardtii lacking the 23 kDa extrinsic subunit1996Inngår i: Photosynthesis - From Light to Biosphere: Proceedings of the 10th International congress, Montpellier, France, 20-25 August 1995. Vol 2 / [ed] Mathis, Paul, Dortrecht: Kluwer Academic Publishers, 1996, s. 291-294Konferansepaper (Annet vitenskapelig)
  • 43.
    Rådberg, Weronica
    Karlstads universitet, Institutionen för kemi.
    Determination of Distribution of Fines in a Paper Structure using Fluorescence Microscopy- an introduction2010Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    When making paper, fibers and additives are suspended in water to a fiber suspension. The sheet is formed by draining a specific amount of suspension through a wire-cloth. The procedure is well known, but the underlying mechanisms are not fully understood. To understand how the different particles such as fines, fibers, retention aids and other additives interact with each other, further research is needed. This knowledge is important because in the production of paper, the retention and the distribution of fines and additives within a paper structure are vital parameters for the properties and also for the profitability of the final product. In this study fluorescence microscopy was used to study fines from bleached kraft pulp which were labeled with fluorophores. When the fines exhibit fluorescence we can study their individual trajectories and understand more about the interactions between fibers, fines and additives in different chemical environments. Fines from bleached kraft pulp have no fluorescent properties and therefore it is necessary to bind a fluorophore to the material. It was difficult to find a suitable fluorophore which binds covalently to the cellulose, the dominating part of fines. The result from this study was that the labeled fines did exhibited fluorescence. As the fines were aggregated no individual trajectories could be analyzed with fluorescence microscopy. Further development of the technique for labeling fines must be carried out to avoid aggregation of fines.

  • 44.
    Stenklo, Katarina
    et al.
    Karlstads universitet, Institutionen för kemi.
    Danielsson Thorell, Helena
    Karlstads universitet, Institutionen för kemi.
    Bergius, Helena
    Karlstads universitet, Institutionen för kemi.
    Aasa, Roland
    Department of Molecular Biotechnology, Chalmers University of Technology, Lundberg Laboratory.
    Nilsson, Thomas
    Karlstads universitet, Institutionen för kemi.
    Chlorite dismutase from Ideonella dechloratans2001Inngår i: Journal of Biological Inorganic Chemistry, ISSN 0949-8257, E-ISSN 1432-1327, J Biol Inorg Chem 2001 June;5 (5-6):601-7, Vol. 6, nr 5-6, s. 601-607Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Chlorite dismutase has been purified from the chlorate-metabolizing bacterium Ideonella dechloratans. The purified enzyme is tetrameric, with a relative molecular mass of 25,000 for the subunit, and contains about 0.6 heme/subunit as isolated. Its catalytic properties are similar, but not identical, to those found for a similar enzyme purified earlier from the bacterium GR-1. The heme group in Ideonella chlorite dismutase is readily reduced by dithionite, in contrast to the GR-1 enzyme, and redox titration gave a value of -21 mV for the midpoint potential at pH 7. The heme group has been characterized by optical and EPR spectroscopy. It is high-spin ferric at neutral pH, with spectroscopic properties similar to those found for cytochrome c peroxidase. In the alkaline pH range, a low-spin compound is formed. A 22-residue N-terminal amino acid sequence has been determined and no homologue has been found in the protein sequence databases.

  • 45.
    Stjernlöf, Anna
    Karlstads universitet, Institutionen för kemi.
    Portable capillary electrophoresis system with LED-absorbance photometric and LED-induced fluorescence detection: Design, characterisation and testing2008Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Capillary electrophoresis (CE) has a wide range of applications in the field of analytical chemistry. In general the most expensive part in a CE system is the detector due to the fact that the detector must have a high sensitivity for small detection volumes and low concentrations. Building portable instruments is one way to make the instruments cheaper and has the advantage that they can be used virtually everywhere. However, downscaling of CE instruments puts some extra demands on the detector. This report describes the design and building of two homemade light-emitting diode (LED) based detectors; a LEDabsorbance photometric detector (LED-AP) and a LED-induced fluorescence (LED-IF) detector. The main goal was to install them inside a portable CE and make a simple separation. The performance of the two detectors had to be evaluated before the main goal could be achieved. p-Nitrophenol was used to create a sensitivity graph for the LED-AP detector, calculating the upper linearity to 5.6 mM when the sensitivity had dropped 10 % caused by non-linearity. The sensitivity graph also showed that the detector had an effective pathlength of 74.2 µm and a stray light of 4.5 % for a 75 µm i.d fused-silica capillary. The LED-IF detector was evaluated by determining the limit of detection (LOD) for fluorescein, at a signal to noise ratio of 3. The LOD was 0.72 µM ± 0.01 µM when immersion oil was used to limit the light scattering from the optic fibres in to the capillary and 0.58 µM ±0.02 µM when silicone oil was used. Without doing any improvements only the LED-AP detector could be used in the portable CE. As a common application area for portable CE instruments is environmental analysis, indirect detection using p-nitrophenol as a probe for separating anions was done to test the system. All analytes were eluted in less than 4 minutes.

  • 46.
    Sundberg, Veronica
    Karlstads universitet, Institutionen för kemi.
    Projektering av en etanolfermenteringsanläggning i pilotskala med Biostilteknologi2007Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Abstract

    This degree thesis was made in cooperation with Chematur Engineering in Karlskoga.

    Many of the environmental issues of today are a result of the motor traffic. Consumption of fossil fuels harms our environmental through formation of carbon dioxide and other greenhouse gases. To get under control with our environmental issues it’s important to find substitutes for oil that are both cheap and environmentally friendly. Ethanol has a long history as a motor fuel and is both enviromentally friendly has a high efficiency.

    According to the EU commissions directives for motor fuels, 5, 75 % of all the fuels in Sweden should be renewable in 2010. Ethanol is international the most widely used and imported renewable fuel. 70 millions litres of ethanol is manufactured in Sweden yearly and the majority comes from the factory in Norrköping owned by Lantmännen. In order to make the Swedish ethanol more competitive the import duty has been increased in 2007.

    The ethanol produced in Sweden mainly is made from wheat and grain, while the production in USA mainly is corn based.

    Ethanol can be manufactured by fermentation from all materials containing suger or some form of chemical composition that can be transformed into suger. The raw material used for ethanol production can be divided into three groups: suger, starch and cellulose.

    Biostil is a process developed in order to make ethanol production as cheap and environmentally friendly as possible. This method is used to manufacture both fuel and technichal ethanol. The raw material used is all kinds of starch containing material.

    Chematur Engineering has developed their own concept within biostil called BiostilÒ 2000. Biostil is a recycling concept that gives a high ethanol yield and lower water consumption.

    To be able to develop the biostil furher, Chematur Engineering aims to build a pilot plant on Kilsta industrial estate.

  • 47.
    Westberg, Robert
    Karlstads universitet, Institutionen för kemi.
    En laboratoriestudie över olika processtegs inverkan på flutingens styrke- och krypegenskaper2001Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
  • 48.
    Öhman, Marcus
    Karlstads universitet, Institutionen för kemi.
    Development of new methods for miniaturized separation techniques2004Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The aim of this study has been to develop and investigate separation methods for miniaturized systems. Micro liquid chromatography was coupled on-line with a mass spectrometer equipped with an electrospray ionization source for the separation and characterization of flavonoids in Citrus juices. Capillary electrophoresis was utilized for the separation of four different types of fatty acid isomers. In the micellar electrokinetic chromatography mode the performance of a number of buffer systems with different additives was examined. For the composition of the basic buffers ingredients multivariate methods were employed. In order to improve electrophoretic separations of analytes that easily adsorb onto the capillary wall, e.g. proteins, a new coating method was developed.

    The coated capillaries were tested for a broad range of applications and a new method for fingerprinting peptide digest of a bacterial protein was developed.The main conclusions are that miniaturized systems offer a lot of benefits due to extremely low volume requirement of buffer components as well as samples. These advantages make it possible to use more expensive buffer ingredients and lower the consumption of solvents dramatically. Low sample consumption is desirable in a lot of areas e.g. in the field of analytical biotechnology. Moreover, separation and detection parameters were improved in miniaturized systems.

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