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  • 1.
    Abghoui, Younes
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Computational design, synthesis, and characterization of oseltamivir molecularly imprinted polymers2012Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
  • 2.
    Abrahamsson, Victor
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Development of a fluorometric method for the quantification of sulfite and thiol-containing compounds in beer2011Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sulfite is the most important antioxidant in beer. Quantification of sulfite is crucial due to restrictions as an additive and for investigative purposes of sulfite and thiol-containing proteins role as redox mediators. A method based on fluorometric determination of sulfite and thiol-containing compounds in beer was developed. The analytes were derivatized with ThioGlo®  1 and subsequently separated on a C18 column with wide pore size, featuring a high-performance liquid chromatography system equipped with fluorescence detector. Two peaks corresponding to sulfite derivatives were observed. The two derivatives were assessed with exact mass spectrometry and both provided identical mass spectra. To compensate for adverse matrix effects in samples a matrix-matched calibration curve is proposed. Sulfite diminished in an inverse exponential manner upon hydrogen peroxide addition in beer. The amount of thiol groups decreased when beer was subjected to oxidative stress, thus confirming its antioxidative role in beer.

  • 3.
    Abrahamsson, Victor
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hoff, Signe
    University of Copenhagen, Denmark.
    Nielsen, Nikoline J.
    University of Copenhagen, Denmark.
    Lund, Marianne N.
    University of Copenhagen, Denmark.
    Andersen, Mogens L.
    University of Copenhagen, Denmark.
    Determination of Sulfite in Beer Based on Fluorescent Derivatives and Liquid Chromatographic Separation2012In: Journal of the American Society of Brewing Chemists, ISSN 0361-0470, E-ISSN 1943-7854, Vol. 70, no 4, p. 296-302Article in journal (Refereed)
    Abstract [en]

    A method was developed for quantification of sulfite in beer based on derivatization with the maleimide-derived probe ThioGlo I followed by separation of fluorescent adducts by reversed-phase high-performance liquid chromatography and fluorescence detection. Sulfite gave two ThioGlo 1 derivatives and it was shown by mass spectrometry that both had identical mass spectra. Matrix effects were observed when constructing sulfite standard curves in different beers and, therefore, use of a matrix-matched calibration curve is proposed. ThioGlo I was found to generate fluorescent adducts with both bound and free sulfite, providing a quantification of the total sulfite content in beer. The limit of quantification of sulfite was 0.6 mg/L and the method can be used for quantification of sulfite in highly colored beers.

  • 4.
    Acuña, Ulyana Muñoz
    et al.
    Ohio State University, USA.
    Carcache, Peter J Blanco
    Ohio State University, USA.
    Matthew, Susan
    Ohio State University, USA.
    Carcache de Blanco, Esperanza J
    Ohio State University, USA.
    New acyclic bis phenylpropanoid and neolignans, from Myristica fragrans Houtt., exhibiting PARP-1 and NF-κB inhibitory effects.2016In: Food Chemistry, ISSN 0308-8146, E-ISSN 1873-7072, Vol. 202, p. 269-275Article in journal (Refereed)
    Abstract [en]

    The bioassay-guided fractionation of the aril of Myristica fragrans (mace spice) yielded five phenolic compounds, one new acyclic bis phenylpropanoid (1) and four previously known phenolic compounds: compounds (1) (S) 1-(3,4,5-trimethoxyphenyl)-2-(3-methoxy-5-(prop-1-yl) phenyl)-propan-1-ol, (2) benzenemethanol; α-[1-[2,6-dimethoxy-4-(2-propen-1-yl)phenoxy]ethyl]-3,4-dimethoxy-1-acetate, (3) odoratisol A, phenol, 4-[(2S,3S)-2,3-dihydro-7-methoxy-3-methyl-5-(1E)-1-propenyl-2-benzofuranyl]-2,6-dimethoxy, (4) 1,3-benzodioxate-5-methanol,α-[1-[2,6-dimethoxy-4-(2-propenyl)phenoxy]ethyl]-acetate, (5) licarin C; benzofuran,2,3-dihydro-7-methoxy-3-methyl-5-(1E)-1-yl-2-(3,4,5-trimethoxyphenyl). An NMR tube Mosher ester reaction was used in an approach to characterize and determine the assignment of the absolute configuration of the new isolated chiral alcohol (1). The PARP-1 inhibitory activity was evaluated for compound (1) (IC50=3.04μM), compound (2) (IC50=0.001μM), compound (4) (IC50=22.07μM) and compound (5) (IC50=3.11μM). Furthermore, the isolated secondary metabolites were tested for NF-κB and K-Ras inhibitory activities. When tested in the p65 assay, compounds (2) and (4) displayed potent NF-κB inhibition (IC50=1.5 nM and 3.4nM, respectively).

  • 5.
    Adbo, Karina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Constructing the chemical bond concept2012In: Nankai University, 2012Conference paper (Other (popular science, discussion, etc.))
  • 6.
    Adbo, Karina
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Emergent Chemistry: Using Visualizations to Develop Abstract Thinking and a Sense of Scale Within the Preschool Setting2022In: Active Learning - Research and Practice for STEAM and Social Sciences Education / [ed] Ortega-Sánchez, Delfín, IntechOpen , 2022Chapter in book (Refereed)
    Abstract [en]

    This chapter is a summary of 5-years of research regarding children’s emerging abstract concepts. A longitudinal study focusing on children’s conversations during a series of activities with a chemistry focus was designed and implemented. Results show that practical experience with magnifying glasses, microscopes, and the deconstruction of several items did not provide enough backdrop for the children to imagine what an even smaller world would look like. Instead, the children applied their experiences from the macroscopic world to describe what they saw. It was not until aminations, zooming in from the macroscopic to the atomic and molecular levels were used that the children’s concept of small began to develop. Results show that the next stage of concept development, besides using descriptions from everyday experiences was the realization these were new experiences, that it was in fact something new they were seeing. Animation technology also helped the children realize that atoms and molecules are everywhere in everything, suggesting that the time elapsed between the transition from the macroscopic level to the submicroscopic level also provided the children with a sense of scale.

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  • 7.
    Adbo, Karina
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Kinetics of enantioselective solid-phase extraction on Trager's base molecularly imprinted polymers, in: Molecularly imprinted polymer science and technology2000Conference paper (Refereed)
  • 8.
    Adbo, Karina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Relationships between models used for teaching chemistry and those expressed by students2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is focused upon chemistry as a school subject and students' interpretations and use of formally introduced teaching models. To explore students' developing repertoire of chemical models, a longitudinal interview study was undertaken spanning the first year of upper secondary school chemistry. Matter in its different states was selected as the target framework for this study. The results presented are derived from both generalisations of groups of students as well as a case study describing an individual learner's interpretation of formal content. The results obtained demonstrated that the formal teaching models provided to the students included in this study were not sufficient to afford them a coherent framework of matter in its different states or for chemical bonding. Instead, students' expressed models of matter and phase change were to a high degree dependent on electron movement (Paper I), anthropomorphism (Paper II) and, for one student, a mechanistic approach based on small particles and gravitation (Paper III). The results from this study place focus on the importance of learners' prior learning (previous experiences) and the need to develop a coherent framework of formal teaching models for the nature of matter and phase change.

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  • 9.
    Adbo, Karina
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Andersson, Håkan S.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ankarloo, Jonas
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Karlsson, Jesper G.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Norell, M C
    Olofsson, Linus
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svenson, Johan
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Örtegren, U
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Enantioselective synthetic receptors for Tröger’s base1999In: Bioorganic Chemistry, Vol. 27, no 5, p. 363-371Article in journal (Refereed)
  • 10.
    Adbo, Karina
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Enantioselective SPE on Tröger 's base molecularly imprinted polymers2001Conference paper (Refereed)
  • 11.
    Adbo, Karina
    et al.
    Linnaeus University, Faculty of Social Sciences, Department of Education.
    Taber, Keith
    University of Cambridge, UK.
    Developing an Understanding of Chemistry: A case study of one Swedish student's rich conceptualisation for making sense of upper secondary school chemistry2014In: International Journal of Science Education, ISSN 0950-0693, E-ISSN 1464-5289, Vol. 36, no 7, p. 1107-1136Article in journal (Refereed)
    Abstract [en]

    In this paper, we report a case study of a 16-year-old Swedish upper secondary student's developing understanding of key concept areas studied in his upper secondary school chemistry course. This study illustrates how the thinking of an individual learner, Jesper, evolves over a school year in response to formal instruction in a particular educational context. Jesper presented a range of ideas, some of which matched intended teaching whilst others were quite inconsistent with canonical chemistry. Of particular interest, research data suggest that his initial alternative conceptions influenced his thinking about subsequent teaching of chemistry subject matter, illustrating how students' alternative conceptions interact with formal instruction. Our findings support the claims of some researchers that alternative conceptions may be stable and tenacious in the context of instruction. Jesper's rich conceptualisation of matter at submicroscopic scales drew upon intuitions about the world that led to teaching being misinterpreted to develop further alternative conceptions. Yet his intuitive thinking also offered clear potential links with canonical scientific concepts that could have been harnessed to channel his developing thinking. These findings support the argument that identifying students' intuitive thinking and how it develops in different instructional contexts can support the development of more effective science pedagogy.

  • 12.
    Adbo, Karina
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Vidal Carulla, Clara
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Designing play-based learning chemistry activities in the preschool environment2019In: Chemistry Education Research and Practice, E-ISSN 1756-1108, Vol. 20, no 3, p. 542-553Article in journal (Refereed)
    Abstract [en]

    This study focuses on the design of play-based learning activities for chemistry in preschool. Viewing chemistry as a part of our past and present culture instead of as a subject, provides the backdrop for a more holistic approach to chemistry within this specific environment. A cultural-historical perspective, together with scaffolding, emergent science skills and sustained shared thinking, made up the framework for the design of the learning activities. Results show that when scaffolding and emergent science skills are used within the design, they provide good support for both the content and the teacher in the actual learning situation. Working with scaffolding was also beneficial for professional development. However, for a progressive and inclusive activity design, it is essential to take into account aspects of the immediate environment and methods for direct evaluation.

  • 13.
    Adbo, Karina
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Vidal Carulla, Clara
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Learning About Science in Preschool: Play-Based Activities to Support Children's Understanding of Chemistry Concepts2020In: International Journal of Early Childhood, ISSN 0020-7187, E-ISSN 1878-4658, Vol. 52, no 1, p. 17-35Article in journal (Refereed)
    Abstract [en]

    The study explores children's emerging understanding of an important science concept in chemistry. Play-based learning activities were designed for children to experience and imagine the concept of 'small' as used in chemistry, moving from the visually experienced level of 'small' towards more imaginative understandings. Data were collected through visual ethnography. Analyses of six vignettes of conversations between children and the teacher illustrate development of children's understanding of the focus concept. Deconstruction of everyday items familiar to the children and visual computer animations provided experiences that enabled children to transition from a macro-level of understanding to visualise the molecular/atomic level to differentiate between macro- and micro-understandings of 'small'. A process of 'sustained shared thinking' could describe the teaching/learning processes evident in the children's and teacher's conversations. The analyses suggest that sustained and shared conversations between children and teachers should stem from children's everyday experiences. ResumeL'etude explore chez les enfants la comprehension emergente d'un concept scientifique important en chimie. Des activites d'apprentissage basees sur le jeu ont ete concues pour que les enfants experimentent et imaginent le concept du 'petit' tel qu'il est utilise en chimie, en passant de la decouverte visuelle au niveau du 'petit' vers des comprehensions plus imaginatives. Des donnees ont ete recueillies par le biais de l'ethnographie visuelle. L'analyse de six vignettes de conversations entre les enfants et l'enseignant illustre le developpement chez les enfants de la comprehension du concept examine. La deconstruction d'objets quotidiens familiers pour les enfants et d'animations visuelles sur ordinateur ont fourni des experiences qui ont permis aux enfants de passer d'un niveau de comprehension macro a une visualisation du niveau moleculaire /atomique, et de faire la difference entre les comprehensions macro et micro du 'petit'. Un processus de 'pensee partagee soutenue' pourrait decrire les processus d'enseignement /apprentissage evidents dans les conversations entre enfants et enseignants. Les analyses suggerent que les conversations soutenues et partagees entre les enfants et les enseignants devraient decouler des experiences quotidiennes des enfants. ResumenEl presente estudio explora la comprension reciente de los ninos de un importante concepto de ciencia en el campo de la quimica. Se disenaron actividades ludicas de aprendizaje para que los ninos experimentaran e imaginaran el concepto de tamano "pequeno" segun se utiliza en el campo de la quimica, alternando entre el nivel de experiencia visual del concepto "pequeno" hasta una comprension mas imaginativa. Se recolecto informacion por medio de etnografia visual. Analisis de seis fragmentos de conversaciones entre los ninos y el educador ilustraron el desarrollo de la comprension de los ninos del concepto principal. La deconstruccion de elementos cotidianos comunes para los ninos y las animaciones visuales computarizadas brindaron experiencias que les permitieron a los ninos navegar desde un nivel macro de comprension a visualizar el nivel molecular/atomico, asi como diferenciar entre la comprension macro y micro del concepto "pequeno". Los procesos de ensenanza/aprendizaje que se evidencian en las conversaciones entre ninos y educadores se pueden describir mediante un proceso de "constante pensamiento comun". Los analisis sugieren que conversaciones constantes y compartidas entre ninos y educadores deben emanar de las experiencias cotidianas de los infantes.

  • 14.
    Agell, Blenda
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Effect of Antibacterial Mouthwash on Basal Metabolic Rate in Humans: A Randomized, Double-blinded, Cross-over Study2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The use of mouthwash is a common complement to oral care. However, the physiological implication of this use, besides of effects on oral hygiene, is poorly known. The research of the gut micro flora and its implications on the host is a very active area of research today. Many important connections between the gut micro flora and obesity and diabetes have been found. These billions of bacteria are part of the immune system, they produce essential vitamins and they make inaccessible polysaccharides more digestible to the host, just to mention a few of their symbiotic roles for the host.

    A less explored area is the micro flora in the oral cavity. On the back of the tongue, anaerobic bacteria can reduce dietary nitrate to nitrite which then further can be reduced to nitric oxide, NO. NO is important in several important biological functions, e.g. as a signal substance, vasoregulation, mucus production and antibacterial effects. Vegetables as beetroot and spinach are dietary sources with a high nitrate content. Also drinking water and processed meats can be of relevance. Nitrite is added to processed meat for the prevention of botulism but also adds taste and color.  

    Experiments on humans indicate that mitochondrial efficiency increases after nitrate load, manifested as a decreased oxygen demand during physical exercise. This can also be relevant under conditions where the mitochondrial function is impaired, such as in diabetes and cardiovascular diseases.

    First a pilot study was made to evaluate the nitrate reducing effect from the antibacterial mouthwash. The mouthwash proved very effective. The concentrations of nitrate and nitrite in saliva was analyzed by HPLC and saliva from the antibacterial treatment showed greatly reduced concentrations of nitrite and high concentrations of nitrate. Saliva from placebo mouthwash showed high concentrations of nitrite and low concentrations of nitrate as expected.

    To study the importance of oral bacteria on metabolism, we performed a randomized, cross-over double-blinded study with 19 healthy males between 22-43 years. During two separate three-day periods they used an antibacterial and placebo mouthwash, respectively. On the fourth day their basal metabolic rate (BMR) was measured with an indirect calorimetric system. Moreover, samples from saliva, urine and blood were collected but these results are not included in this thesis. An earlier, unpublished study has demonstrated that nitrate administration reduces the basal metabolic rate. Accordingly, our aim was to study potential effects on the basal metabolic rate following reduction of the number of oral bacteria by aid of antibacterial mouthwash. Our hypothesis was that the reduced availability of nitrite would decrease the availability of NO in the body and manifest as an increased basal metabolic rate.

    The results from indirect calorimetry measurements showed no significant difference between placebo and antibacterial mouthwash, but there may be confounding factors. Further study is needed to assess the potential effects on host metabolism by these bacteria.

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  • 15.
    Ahlin, Ellen
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Utvärdering av dricksvattenkvaliteten i Bjuv: Kartläggning av klagomål och eftersökning av orsak2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vid bytet från grundvattentäkt till ytvattentäkt i Bjuvs kommun började klagomål om dricksvattnets kvalitet att strömma in till Nordvästra Skånes Vatten och Avlopp (NSVA), ansvarig för vattenverksamheten i kommunen. Syftet med denna studie är att kartlägga klagomålen kring dricksvattnet, ringa in problemet och eftersöka orsaken. Detta har skett genom intervjuer med konsumenter liksom vattenprovtagningar hos dessa. En geografisk spridning låg till grund vid valet av provtagningspunkterna. Utöver mikrobiologiska, kemiska och fysikaliska parametrar som inkluderas i Livsmedelsverkets föreskrifter om dricksvatten har vattnet analyserats för innehåll av geosmin, 2-metylisoborneol och 2,4,6-trikloranisol då dessa föreningar är kända för att orsaka dålig lukt och bismak på dricksvatten. Analysresultaten visar generellt på ett vatten med god kvalitet. Av de intervjuer som gjorts hos de utvalda konsumenterna framgår det dock att vattenkvaliteten inte är tillfredsställande. Det är i huvudsak vattnets lukt och smak som kritiseras där unken och mögel är den vanligaste beskrivningen. Vad denna lukt och smak beror på har inte kunnat fastställas. En kartläggning av klagomålen och definiering av problemet har dock påbörjats vilket underlättar för fortsatta studier och eventuella åtgärder.

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  • 16.
    Ahlstrand, Emma
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Hermansson, Kersti
    Uppsala University.
    Friedman, Ran
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Interaction Energies in Complexes of Zn and Amino Acids: A Comparison of Ab Initio and Force Field Based Calculations2017In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 121, no 13, p. 2643-2654Article in journal (Refereed)
    Abstract [en]

    Zinc plays important roles in structural stabilization of proteins, eniyine catalysis, and signal transduction. Many Zn binding sites are located at the interface between the protein and the cellular fluid. In aqueous solutions, Zn ions adopt an octahedral coordination, while in proteins zinc can have different coordinations, with a tetrahedral conformation found most frequently. The dynainics of Zn binding to proteins and the formation of complexes that involve Zn are dictated by interactions between Zn and its binding partners. We calculated the interaction energies between Zn and its ligands in complexes that mimic protein binding sites and in Zn complexes of water and one or two amino acid moieties, using quantum mechanics (QM) and molecular mechanics (MM). It was found that MM calculations that neglect or only approximate polarizability did not reproduce even the relative order of the QM interaction energies in these complexes. Interaction energies calculated with the CHARMM-Diode polarizable force field agreed better with the ab initio results,:although the deviations between QM and MM were still rather large (40-96 kcallmol). In order to gain further insight into Zn ligand interactions, the free energies of interaction were estimated by QM calculations with continuum solvent representation, and we performed energy decomposition analysis calculations to examine the characteristics of the different complexes. The ligand-types were found to have high impact on the relative strength of polarization and electrostatic interactions. Interestingly, ligand ligand interactions did not play a significant role in the binding of Zn. Finally) analysis of ligand exchange energies suggests that carboxylates could be exchanged with water molecules, which explains the flexibility in Zn:binding dynamics. An exchange between earboxylate (Asp/Glii) and imidazole (His) is less likely.

  • 17.
    Ahlstrand, Emma
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Spångberg, Daniel
    Uppsala University.
    Hermansson, Kersti
    Uppsala University.
    Friedman, Ran
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Interaction energies between metal ions (Zn2+ and Cd2+) and biologically relevant ligands2013In: International Journal of Quantum Chemistry, ISSN 0020-7608, E-ISSN 1097-461X, Vol. 113, no 23, p. 2554-2562Article in journal (Refereed)
    Abstract [en]

    Interactions between the group XII metals Zn2+ and Cd2+ and amino acid residues play an important role in biology due to the prevalence of the first and the toxicity of the second. Estimates of the interaction energies between the ions and relevant residues in proteins are however difficult to obtain. This study reports on calculated interaction energy curves for small complexes of Zn2+ or Cd2+ and amino acid mimics (acetate, methanethiolate, and imidazole) or water. Given that many applications and models (e.g., force fields, solvation models, etc.) begin with and rely on an accurate description of gas-phase interaction energies, this is where our focus lies in this study. Four density functional theory (DFT)-functionals and MP2 were used to calculate the interaction energies not only at the respective equilibrium distances but also at a relevant range of ion–ligand separation distances. The calculated values were compared with those obtained by CCSD(T). All DFT-methods are found to overestimate the magnitude of the interaction energy compared to the CCSD(T) reference values. The deviation was analyzed in terms of energy components from localized molecular orbital energy decomposition analysis scheme and is mostly attributed to overestimation of the polarization energy. MP2 shows good agreement with CCSD(T) [root mean square error (RMSE) = 1.2 kcal/mol] for the eight studied complexes at equilibrium distance. Dispersion energy differences at longer separation give rise to increased deviations between MP2 and CCSD(T) (RMSE = 6.4 kcal/mol at 3.0 Å). Overall, the results call for caution in applying DFT methods to metalloprotein model complexes even with closed-shell metal ions such as Zn2+ and Cd2+, in particular at ion–ligand separations that are longer than the equilibrium distances.

  • 18.
    Ahlstrand, Emma
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Zukerman Schpector, Julio
    Universidade Federal de São Carlos, Brazil.
    Friedman, Ran
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Computer simulations of alkali-acetate solutions: Accuracy of the forcefields in difference concentrations2017In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 147, p. 1-10, article id 194102Article in journal (Refereed)
    Abstract [en]

    When proteins are solvated in electrolyte solutions that contain alkali ions, the ions interact mostlywith carboxylates on the protein surface. Correctly accounting for alkali-carboxylate interactionsis thus important for realistic simulations of proteins. Acetates are the simplest carboxylates thatare amphipathic, and experimental data for alkali acetate solutions are available and can be comparedwith observables obtained from simulations. We carried out molecular dynamics simulations of alkali acetate solutions using polarizable and non-polarizable forcefields and examined the ionacetateinteractions. In particular, activity coefficients and association constants were studied in a range of concentrations (0.03, 0.1, and 1M). In addition, quantum-mechanics (QM) based energy decomposition analysis was performed in order to estimate the contribution of polarization, electrostatics, dispersion, and QM (non-classical) effects on the cation-acetate and cation-water interactions. Simulations of Li-acetate solutions in general overestimated the binding of Li+ and acetates. In lower concentrations, the activity coefficients of alkali-acetate solutions were too high, which is suggested to be due to the simulation protocol and not the forcefields. Energy decomposition analysis suggested that improvement of the forcefield parameters to enable accurate simulations of Li-acetate solution scan be achieved but may require the use of a polarizable forcefield. Importantly, simulations with some ion parameters could not reproduce the correct ion-oxygen distances, which calls for caution in thechoice of ion parameters when protein simulations are performed in electrolyte solutions.

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  • 19.
    Airey, John
    et al.
    Stockholm University, Sweden.
    Patron, Emelie
    Linnaeus University, Faculty of Social Sciences, Department of Education and Teacher's Practice. Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Wikman, Susanne
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Making the Invisible Visible: The role of undergraduate textbooks in the teaching and learning of physics and chemistry2023In: Designing futures: The 11th International Conference on Multimodality; Book of abstracts, London Conference, London: UCL , 2023Conference paper (Refereed)
    Abstract [en]

    As disciplines, undergraduate physics and chemistry leverage a particularly wide range of semiotic systems (modes) in order to create and communicate their scientific meanings. Examples of the different semiotic systems employed are: spoken and written language, mathematics, chemical formulae, graphs, diagrams, sketches, computer simulations, hands-on work with experimental apparatus, computer simulations, etc. Individual semiotic resources within this range of semiotic systems are coordinated in specific constellations (Airey & Linder, 2009) in order to mediate scientific knowledge. In this Swedish Research Council project, we are interested in the representation of scientific phenomena that cannot be seen. The question we pose is: How is scientific knowledge mediated when we cannot directly interact with the phenomena in question through our senses?  We adopt a social semiotic approach (Airey & Linder, 2017; van Leeuwen, 2005), to investigate the ways in which two phenomena—electromagnetic fields and chemical bonds—are presented in undergraduate textbooks. To do this we carried out a semiotic audit (Airey & Erikson, 2019) of eight textbooks (four in each discipline). We note that the individual resources used have a mixture of affordances—whilst the majority retain high disciplinary affordance, others are unpacked (Patron et al. 2021) providing higher pedagogical affordance. We discuss the ways in which the resources have been combined and orchestrated (Bezemer & Jewitt, 2010) in order to attempt to make visible that which is invisible, and identify a number of potential problems. In earlier work, Volkwyn et al. (2019) demonstrated how experimental work with physics devices can make the Earth’s magnetic field accessible to students through chains of transduction. Thus, we propose that encouraging transductions across the semiotic resource systems provided in textbooks may help students to experience the invisible.

    References

    Airey, J. (2006). Physics students' experiences of the disciplinary discourse encountered in lectures in English and Swedish (Licentiate dissertation, Department of Physics, Uppsala University).

    Airey, J. (2009). Science, language, and literacy: Case studies of learning in Swedish university physics (Doctoral dissertation, Acta Universitatis Upsaliensis).

    Airey, J. (2015). Social Semiotics in Higher Education: Examples from teaching and learning in undergraduate physics. In In: SACF Singapore-Sweden Excellence Seminars, Swedish Foundation for International Cooperation in Research in   Higher Education (STINT) , 2015 (pp. 103). 

    Airey, J., & Eriksson, U. (2019). Unpacking the Hertzsprung-Russell diagram: A social semiotic analysis of the disciplinary and pedagogical affordances of a central resource in astronomy. Designs for Learning, 11(1), 99-107.

    Goodwin, C. (2015). Professional vision. In Aufmerksamkeit: Geschichte-Theorie-Empirie (pp. 387-425). Wiesbaden: Springer Fachmedien Wiesbaden.

    O’Halloran, K. (2007). Mathematical and scientific forms of knowledge: A systemic functional multimodal grammatical approach. language, Knowledge and pedagogy: functional linguistic and sociological perspective, 205-236.

    Patron, E. (2022). Exploring the role that visual representations play when teaching and learning chemical bonding: An approach built on social semiotics and phenomenography(Doctoral dissertation, Linnaeus University Press).

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    Presentation
  • 20.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Elastic Properties and Hardness of Mixed Alkaline Earth Silicate Oxynitride Glasses2022In: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 15, no 14, article id 5022Article in journal (Refereed)
    Abstract [en]

    The incorporation of nitrogen as a second anion species into oxide glasses offers unique opportunities for modifying glass properties via changes in glass polymerization and structure. In this work, the compositional dependence of elastic properties and the nanoindentation hardness of mixed alkaline-earth silicate oxynitride glasses containing a high amount of nitrogen (>15 at.%, c.a. 35 e/o) were investigated. Three series of silicon oxynitride glass compositions AE-Ca-Si-O-N glasses (where AE = Mg, Sr, and Ba) having varying amounts of modifiers were prepared using a new glass synthesis route, in which a precursor powder of metal hydrides was used. The obtained glasses contained high amounts of N (19 at.%, c.a. 43 e/o) and modifier cations (26 at.%, c.a. 39 e/o). Mg-Ca-Si-O-N glasses had high values of nanohardness (12-16 GPa), along with a reduced elastic modulus (130-153 GPa) and Young's modulus (127-146 GPa), in comparison with the Sr-Ca- and Ba-Ca-bearing oxynitride glasses. Both the elastic modulus and the nanohardness of AE-Ca-Si-O-N glasses decreased with an increase in the atomic number of the AE element. These property changes followed a linear dependence on the effective cation field strength (ECFS) of the alkaline earth (AE) modifier, according to their valences and ionic radii. No mixed alkaline-earth effect was observed in the current investigation, indicating that the properties were more dictated by the nitrogen content.

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  • 21.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Hakeem, Abbas Saeed
    King Fahd Univ Petr & Minerals, Saudi Arabia.
    Eriksson, Mirva
    Stockholm University, Sweden.
    Wojcik, Natalia Anna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gdansk Univ Technol, Poland.
    A novel approach for processing CaAlSiON glass-ceramics by spark plasma sintering: Mechanical and electrical properties2022In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 42, no 1, p. 96-104Article in journal (Refereed)
    Abstract [en]

    Lithium containing glassy materials can be used as solid electrolytes or electrode materials for lithium-ion batteries due to their high energy density. Conventional melt-quenched Ca11Al14Si16O49N10 glass powder containing 24 e/o N, doped with Li-ions (1, 3, and 6 wt. %) and sintered by spark plasma sintering technique (SPS) was studied. The benefits of using SPS to produce glass-ceramics are rapid heating rates compared to conventional consolidation techniques and tuning of properties, adjusting the temperature, holding time (closed to Tg temperature), heating rate (solidification), and pressure (densification) profile during the heat treatment using SPS. Pure glass and glass-ceramic were obtained under identical SPS conditions and compared with pristine oxynitride and soda-lime-silicate (float) glasses. XRD and SEM analysis confirmed that increasing the amount of Li increases the crystallinity in the glass matrix. Nano-indentation analysis showed a decreased hardness and reduced elastic modulus values with the addition of Li-ions. The direct current conductivity increases with the addition of Li due to the high mobility of Li-ions. However, the float glass sample doped with 6 wt.% of Li exhibits even higher values of D.C. conductivity, than the analogously doped Ca11Al14Si16O49N10 glass. The magnitude of activation energy (more than 1 eV) is typical for an ion hopping mechanism and the D.C. conduction mechanism is dominated by Li+ hopping.

  • 22.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Difficulties associated with the formation of oxynitride glasses2014Conference paper (Refereed)
  • 23.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Formation and properties of nitrogen rich Ca-Si- (Al)-O-N glasses and Ceramics2014In: Conference proceeding 2014 Spring World Congress on Engineering and Technology, Shanghai, China (April 2014)., 2014, p. 59-59Conference paper (Refereed)
  • 24.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Properties of nitrogen rich mixed La-Pr silicon oxynitride glasses2014Conference paper (Refereed)
  • 25.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    J. Pomeroy, Michael
    University of Limerick, Ireland.
    Stuart, Hampshire
    University of Limerick, Ireland.
    Issues associated with the development of transparent oxynitride glasses2015In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 41, no 3, p. 3345-3354Article in journal (Refereed)
    Abstract [en]

    Oxynitride glasses and glass ceramics are increasingly recognized as potential materials in specialist applications in modern industrial sectors. Oxynitride glasses have superior mechanical, rheological and optical properties to their oxide glass counterparts. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. In contrast to oxide glasses, oxynitride glasses are difficult to prepare which adds to production costs. Furthermore, they contain impurities in the form of elemental silicon and silicides, have poor oxidation resistance in air above their glass transition temperatures and have poor transparency in the visible region. This article reviews the above issues in relation to the potential applications of these glasses.

  • 26.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Greczynski, Grzegorz
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Novel transparent Mg-Si-O-N thin films with high hardness and refractive index2016In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 131, p. 1-4Article in journal (Refereed)
    Abstract [en]

    There is an increasing demand for glass materials with better mechanical and optical properties for display and electronic applications. This paper describes the deposition of novel thin films of Mg-Si-O-N onto float glass substrates. Amorphous thin films in the Mg-Si-O-N system with high nitrogen and magnesium contents were deposited by reactive RF magnetron co-sputtering from Mg and Si targets in Ar/N2/O2 gas mixtures. The thin films studied span an unprecedented range of compositions up to 45 at% Mg and 80 at% N out of cations and anions respectively. Thin films in the Mg-Si-O-N system were found to be homogeneous and transparent in the visible region. Mechanical properties like hardness (H) and reduced elastic modulus (Er) show high values, up to 21 GPa and 166 GPa respectively. The refractive index (1.87-2.00) increases with increasing magnesium and nitrogen contents.

  • 27.
    Alice, Landmér
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Wet spinning of carbon fiber precursors from cellulose-lignin blends in a cold NaOH(aq) solvent system2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Carbon fiber (CF) is predominantly produced from fossil-based sources and is therefore an area of interest for further development towards a more sustainable society. The purpose of this thesis work was to investigate the possibility of producing precursor fibers (PFs) for CF production from a blend of renewable cellulose andlignin. Cellulose, which is used to some extent for CF production, was chosen, while the possibility of adding lignin was investigated in hope of increasing the gravimetric yield of the CF production. Blends of softwood kraft cellulose pulp (SKP) and softwood kraft lignin (SKL) were dissolved in an alkaline (NaOH) solvent system at different cellulose/lignin ratios. A total of eight dopes were prepared (SKP/SKL ratios of 100/0–60/40 wt./wt.) with total dope concentrations ranging from 4.5 wt.% to 9.2 wt.%. The addition of SKL resulted in dark colored dopes with viscosities of which mainly appeared to depend on the SKP concentration. The dopes were wet spun, resulting in continuously spun PFs. The PFs showed on an increasing pyrolysis yield with increased SKL content but decreasing mechanical properties. However, process optimization was not included in the work, subsequently leading to the assumption that greater values on mechanical properties can be achieved. A pure SKP PF and a SKP-SKL (70/30 wt./wt.) PF were successfully thermally converted into CFs by carbonization at 1000 °C. The PF containing SKL had a total gravimetric yield more than twice as high as the pure SKP PF, 28 wt.% and 12 wt.%, respectively. Thereby, the addition of SKL seems to have a positive impact on the CF yield when utilizing a NaOH(aq) solvent system. This thesis work has become a base for the future work towards the development of CFs from wet spun cellulose-lignin PFs in the NaOH(aq) solvent system.  

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  • 28.
    Allender, Chris J.
    et al.
    Cardiff University, UK.
    Andersson, Håkan S.
    University of Kalmar, School of Pure and Applied Natural Sciences. Cardiff University, UK.
    Brain, Keith R.
    Cardiff University, UK.
    Ramström, Olof
    Cardiff University, UK.
    Preface2001In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 435, no 1, p. 1-2Article in journal (Other academic)
  • 29.
    Alnehmry, Shaima
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Effektiviteten av läkemedelsbehandling för att minska muntorrhet och förebygga karies2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Background: Dry mouth (xerostomia) is a common symptom which is connected with hypofunction of salivary glands induced by transient physiological conditions, pathology or as a side effect of drugs or radiation. Xerostomia almost always develops after destruction of salivary glands in connection with the treatment of head and neck cancer with ionizing radiation. Certain autoimmune diseases such as Sjogren's syndrome can also give dry mouth symptoms. The use of anticholinergic drugs and certain antihistamines may also cause a decrease in salivation. Aging is another factor that can induce salivary gland hypofunction due to physiological changes and/or use of medications. The treatment goals for patients with dry mouth is to relieve symptoms, prevent or ameliorate the consequences of salivary dysfunction, and treating the underlying disease. Treatments to improve function include saliva stimulation and saliva substitutes with fluoride. The systemic drugs bromhexine and pilocarpine are tested as saliva stimulants. Pilocarpine (Salagen) is a non-selective muscarinic agonist that increases the secretion of saliva.

    The purpose of this thesis was to investigate the effect of drug treatments to reduce dry mouth and prevent tooth decay, with the help of scientific articles.

    Results showed that in patients with some remaining unstimulated salivary flow rate daily treatments with a fluoride concentration of 0.42% F was enough to prevent tooth decay to a large extent. Use of 1.23% F-gel was not better than the 0.42% gel treatment. Casein derivatives complexed with calcium phosphate could be an alternative to fluoride treatment. Salivary secretion increased significantly after mouth rinse with 1% or 2% pilocarpine with a plateau between 45 and 75 minutes. 2% pilocarpine solution also increased the sense of salivary flow. Dry mouth was improved in 12.1; 63.6; 69.7 % of the patients who received Salagen tablets (5mg pilocarpine hydrochloride), 3mg or 5mg pilocarpine lozenge, respectively, compared with 42.4 % of patients receiving placebo lozenge. Mouth wash with pilocarpine 0.1% increased secretion from minor salivary glands and whole unstimulated saliva secretion compared to 0.9% saline mouthwash. The effectiveness in relieving subjective dry mouth was not significantly different between the solutions.

    Conclusions: Patients with unstimulated salivary flow <0.1 ml / min have a higher risk of caries lesions compared to unstimulated salivary flow> 0.1 ml / min. Patients with stimulated salivary flow <0.5 ml / min have a higher risk of caries lesions compared to stimulated salivary flow >0.5 ml / min. Mouthwash with pilocarpine solutions at concentrations of 1-2% pilocarpine induce a significant objective and subjective dose dependent increase in salivary flow. Pilocarpine lozenge produced the better clinical responses and a faster subjective improvement of dry mouth than Salagen tablets.

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    Shaima examensarbete
  • 30.
    Amann, Laura
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Development and Validation of an Analytical Method for Phenolic Acid Extraction from Cereals and Quantification using HPLC-UV2018Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Cereals are rich in phenolic acids, a group of secondary plant metabolites that are associated with reduced risk of chronic diseases. The objective was to develop and internally validate a method for extraction and quantification of phenolic acids in cereals using HPLC-UV and to apply this method for quantification of the content of phenolic acids in several species of Swedish cereals. Different procedures for extraction of phenolic acids from cereal grains using acid or base hydrolysis with and without subsequent enzymatic treatment were tested. Both the extraction procedure and the chromatographic conditions for quantification with HPLC-UV were optimized. Phenolic acids from 14 cereal samples, representing different cultivars of rye, wheat, barley, and oat, were extracted and analyzed under optimized conditions. Using the optimized method, 15 phenolic acids could be quantified with limits of detection and quantification ranging from 0.4 to 11.4 µg/g and from 1.3 to 38.0 µg/g, respectively. The hydrolysis procedure and further sample treatment showed a substantial effect on the yield of phenolic acids from cereals. The highest yield was achieved by 90‑minute base hydrolysis at room temperature using sodium hydroxide solution containing ascorbic acid and EDTA. Mean recoveries ranged from 88 to 108%. The following phenolic acids were found in the analyzed cereal grains with ferulic acid being the most abundant one: p‑hydroxybenzoic acid, vanillic acid, vanillin, caffeic acid, syringic acid, ferulic acid, sinapic acid, and 3,4‑dihydroxybenzaldehyde. A further compound was p‑coumaric acid or the co‑eluting syringaldehyde or a mixture of both. The content of phenolic acids in Swedish cereals ranged from 6 µmol/g DM in rye to 3 µmol/g DM in oat and a barley cultivar. In conclusion, a simple and accurate method for extraction and quantification of phenolic acids in cereals was developed and successfully applied.

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    Master's Thesis
  • 31.
    Anaspure, Prasad
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Novel strategies for C-C/X bond formation2022Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The formation of C-C/X bonds is essential for the manufacture of a broad range of chemicals and materials used in areas critical for maintaining quality of life in modern society, e.g. pharmaceuticals, agrochemicals and polymers, and for aspects of research in organic chemistry. The use of catalysts for facilitating these reactions is highly desirable due to the improvements in energy and atom economies that can potentially be achieved.The primary objective of the thesis was to explore novel approaches for catalysis of C-C/X bond-forming reactions, both through C-H activation. In paper I, at unable cobalt catalyzed C-H activation-driven annulation of benzamides with unsymmetrical diynes was developed, where either 3- or 4-substitution of the isoquinolone could be steered by the nature of the diyne used. Anunprecedented iridium catalyzed tandem bis-arylsulfenylation of indoles was described (paper II), where an adamantoyl sacrificial directing group plays a key role in the simultaneous direction of arylsulfenylation to the 2- and 4- positions. In paper III, a flow reactor in a lab-on-a-chip device was developed for the Suzuki cross-coupling reaction. Miniaturization provides the opportunity to reduce material consumption. Polyethyleneimine (PEI)-brushes were used for the immobilization of Pd-nanoparticles, and high efficiencies were observed. Collectively, the research underpinning this thesis provides new strategies forC-C and C-X(S) bond formation.

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  • 32.
    Anaspure, Prasad
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Suriyanarayanan, Subramanian
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Nicholls, Ian A.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences. Linnaeus University, Linnaeus Knowledge Environments, Advanced Materials.
    Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context2021In: RSC Advances, E-ISSN 2046-2069, Vol. 11, no 56, p. 35161-35164Article in journal (Refereed)
    Abstract [en]

    Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions. This thin film-format demonstrated good catalytic efficiency (TON up to 3.4 x 10(3)) and stability. Incorporation into a quartz crystal microbalance (QCM) instrument illustrated the potential for using this approach in lab-on-a-chip-based synthesis applications.

  • 33. Anderbrant, Olle
    et al.
    Matteson, Donald S.
    Unelius, C. Rikard
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Pharazyn, Philip S
    Santangelo, Ellen M.
    Schlyter, Fredrik
    Birgersson, Göran
    Pheromone of the elm bark beetle Scolytus laevis (Coleoptera: Scolytidae): stereoisomers of 4-methyl-3-heptanol reduce interspecific competition2010In: Chemoecology, ISSN 0937-7409, E-ISSN 1423-0445, Vol. 20, no 3, p. 179-187Article in journal (Refereed)
    Abstract [en]

    Stereoisomers of 4-methyl-3-heptanol (MH) are pheromone components of several Scolytus bark beetles. The elm bark beetle Scolytus laevis (Coleoptera: Scolytidae) has in previous studies been caught in traps baited with commercial MH containing all four stereoisomers, but the lure has been considered a weak attractant. In this study, we addressed the question whether stereospecific responses by S. laevis to stereoisomers of MH might contribute to its niche separation from other sympatric Scolytus species. Using GC–MS, we analyzed extracts of hindguts and abdomens from male and female S. laevis and the sympatric S. triarmatus. We also tested all four MH-stereoisomers individually and in combinations in the field to determine their role for S. laevis. All four stereoisomers were synthesized via a boronic ester method with 1,2-dicyclohexylethanediol as chiral director. In addition, the (3S,4R)-stereoisomer of MH was prepared through enantioselective, lipase-mediated transesterification of a mixture of the four stereoisomers of MH. Females of both species contained small amounts of syn-MH, and males contained trace amounts of anti-MH. The anti stereoisomer (3R,4S)-MH was attractive to male and female S. laevis, whereas the syn stereoisomer (3S,4S)-MH acted as an inhibitor or deterrent and reduced the catch when added to the attractive isomer. The syn isomer is the main aggregation pheromone component of the larger and sympatric S. scolytus and possibly also of S. triarmatus. The avoidance response of S. laevis to the (3S,4S)-stereoisomer may reduce interspecific competition for host trees.

  • 34.
    Andersson, Fredrik
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Studies on organic liquid baby-food gruel: The effect of including organic flour and starch from corn2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Introduction: Studies conducted on foods aimed for infants and young children have shown that foods containing rice have a high content of arsenic and cadmium. Arsenic and cadmium are toxic elements classified as carcinogens. It is therefore especially important to keep the levels low in foods for infants and young children since they have a high intestinal absorption and since the negative effects become apparent only after many years of chronic exposure.

    Aim: The aim of this project was to investigate if the rice flour in baby-food gruel could be replaced with corn flour with the aim to decrease the content of primarily arsenic and cadmium and sustain low levels of lead and mercury while retaining sensory properties. A native corn starch was also evaluated in terms of heavy metal content and sensory properties.

    Material & Methods: The rice flour in 4 different recipes was replaced with various proportions of flour and starch from corn whereon sensory evaluations were performed. Stability and viscosity measurements were conducted and the content of arsenic, cadmium, lead and mercury was analysed.

    Results/Conclusion: No differences in texture and mouth feel could be perceived at low corn flour concentrations when mixed with rice flour. Replacement of 60% of the rice flour fraction with corn flour in a gruel which contained 1.1% rice flour (w/w), may have led to an increased arsenic content. The corn starch provided the highest viscosity and had a smoother mouth feel at the same concentration compared to the corn flour and might be a better choice than the corn flour. In addition, corn starch had a lower content of cadmium and lead compared to the corn flour but further research is needed to establish which one contains the lowest level of arsenic. Both had a lower content of arsenic compared to the rice flour when the flours were analysed separately.

  • 35.
    Andersson, Håkan S.
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Figueredo, Sharel M.
    Haugaard-Kedström, Linda M.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Bengtsson, Elina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Daly, Norelle L.
    Qu, Xiaoqing
    Craik, David J.
    Ouellette, Andre J.
    Rosengren, K. Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    The alpha-defensin salt-bridge induces backbone stability to facilitate folding and confer proteolytic resistance2012In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 43, no 4, p. 1471-1483Article in journal (Refereed)
    Abstract [en]

    Salt-bridge interactions between acidic and basic amino acids contribute to the structural stability of proteins and to protein-protein interactions. A conserved salt-bridge is a canonical feature of the alpha-defensin antimicrobial peptide family, but the role of this common structural element has not been fully elucidated. We have investigated mouse Paneth cell alpha-defensin cryptdin-4 (Crp4) and peptide variants with mutations at Arg(7) or Glu(15) residue positions to disrupt the salt-bridge and assess the consequences on Crp4 structure, function, and stability. NMR analyses showed that both (R7G)-Crp4 and (E15G)-Crp4 adopt native-like structures, evidence of fold plasticity that allows peptides to reshuffle side chains and stabilize the structure in the absence of the salt-bridge. In contrast, introduction of a large hydrophobic side chain at position 15, as in (E15L)-Crp4 cannot be accommodated in the context of the Crp4 primary structure. Regardless of which side of the salt-bridge was mutated, salt-bridge variants retained bactericidal peptide activity with differential microbicidal effects against certain bacterial cell targets, confirming that the salt-bridge does not determine bactericidal activity per se. The increased structural flexibility induced by salt-bridge disruption enhanced peptide sensitivity to proteolysis. Although sensitivity to proteolysis by MMP7 was unaffected by most Arg(7) and Glu(15) substitutions, every salt-bridge variant was degraded extensively by trypsin. Moreover, the salt-bridge facilitates adoption of the characteristic alpha-defensin fold as shown by the impaired in vitro refolding of (E15D)-proCrp4, the most conservative salt-bridge disrupting replacement. In Crp4, therefore, the canonical alpha-defensin salt-bridge facilitates adoption of the characteristic alpha-defensin fold, which decreases structural flexibility and confers resistance to degradation by proteinases.

  • 36.
    Andersson, Håkan S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Jacobsson, Erik
    Uppsala University.
    Eriksson, Camilla
    Uppsala University.
    Hedström, Martin
    Lund University.
    Seth, Henrik
    University of Gothenburg.
    McEvoy, Eric G
    Liverpool John Moores University.
    Sundberg, Per
    University of Gothenburg.
    Strand, Malin
    Swedish University of Agricultural Sciences.
    Göransson, Ulf
    Uppsala University.
    Discovery of peptide toxins in ribbon worms: challenging claims of tetrodotoxin production2015Conference paper (Other academic)
  • 37.
    Andersson, Håkan S.
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Chemistry and Biomedical Sciences.
    Jacobsson, Erik
    Uppsala University.
    Eriksson, Camilla
    Uppsala University.
    Rosengren, K. Johan
    University of Queensland, Australia.
    Andrén, Per
    Uppsala University.
    Strand, Malin
    Swedish agricultural university (SLU).
    Göransson, Ulf
    Uppsala University.
    Discovery of peptide toxins in the bootlace worm, the world's longest animal2015Conference paper (Other academic)
  • 38.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Karlsson, Jesper G.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Piletsky, S A
    Koch-Schmidt, Ann-Christin
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Mosbach, K
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Influence of monomer-template ratio on selectivity and load capacity of molecularly imprinted polymers: indications of template self-association1999In: Journal of Chromatography A, Vol. 848, no 1-2, p. 39-49Article in journal (Refereed)
  • 39.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Karlsson, Jesper G.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Svenson, Johan
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nicholls, Ian A.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Can template-template self-association contribute to polymer-ligand recognition characteristics?2000Conference paper (Refereed)
  • 40.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Koch-Schmidt, Ann-Christin
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Ohlson, Sten
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Study of the Nature of Recognition in Molecularly Imprinted Polymers1996In: J. Mol. Recogn., Vol. 9, p 675-682Article in journal (Refereed)
  • 41.
    Andersson, Håkan S.
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Koch-Schmidt, Ann-Christin
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    University of Kalmar, School of Pure and Applied Natural Sciences.
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  • 50.
    Andreasson, Johan
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Emissioner av flyktiga organiska föreningar från vattenburna lacker2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Arbetet har jämfört de emissioner som olika tjocklek på lacklagren samt olika torkningstemperaturer ger upphov till. Det konstaterades att tjocka lager ger upphov till oproportionerligt höga emissioner både på kort och framförallt på lång sikt. En högre torkningstemperatur orsakar lägre emissioner på kort sikt men lika höga eller högre på lång sikt. Inverkan från underlaget som lacken applicerades på undersöktes också och där konstaterades att ett porösare medium, i detta fall en MDF-skiva, orsaker lägre emissioner. Sannolikt pga att ämnena sugs upp av materialet. Den tredje delen bestod i att jämföra olika testkammares förmåga att registrera de sökta ämnena. Två stycken kammare med volymen 1m3 och en liten kammare med volymen 3ml användes. Det visade sig att de båda stora kamrarna visade liknande resultat om tiden efter att lacken applicerats på proverna var densamma. Den mindre visade klart lägre koncentrationer i försöksluften men omräknat till ytspecifik utsöndring var värdena jämförbara. Ämnen med hög kokpunkt var överrepresenterade i den lilla kammaren och ämnen med låg kokpunkt underrepresenterade, vilket gör att kammaren lämpar sig bäst för jämförande studier.

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