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  • 1. Abe, Minori
    et al.
    Tsutsui, Takashi
    Tokyo Metropolitan Univ, Grad Sch Sci, Dept Chem, Tokyo, Japan..
    Ekman, Jörgen
    Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM).
    Hada, Masahiko
    Das, Bhanu
    Accurate determination of the enhancement factor X for the nuclear Schiff moment in (TlF)-Tl-205 molecule based on the four-component relativistic coupled-cluster theory2020In: Molecular Physics, ISSN 0026-8976, E-ISSN 1362-3028, Vol. 118, no 23, article id e1767814Article in journal (Refereed)
    Abstract [en]

    Studies of parity (P) and time-reversal (T) symmetry violations using molecules are important and attractive because they are complementary to the high-energy tests of physics beyond the Standard Model of elementary particles. The focus of our present work is to surpass the current accuracies of the quantity X, an enhancement factor for the nuclear Schiff moment (Q), and the nucleon electric dipole moments for the (TlF)-Tl-205 molecule. We obtain X = 6856 a.u. using a relativistic coupled-cluster singles and doubles and perturbative triples (CCSD(T)) approach. This new value of X improves the upper limits for Q and the proton EDM by about ten percent over the previous ones. [GRAPHICS] .

  • 2.
    Abou Assaf, Mohamad
    Malmö University, Faculty of Education and Society (LS).
    kemiundervisning utifrån flerspråkiga elevers språkutveckling2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna studie belyser de svårigheter som flerspråkiga elever möter i kemiämnet vilket påverkar deras utveckling och hindrar dem att nå kunskapskraven. Studien lägger särskilt fokus på de undervisningsmetoder som lärare använder och det stöd som flerspråkiga elever får för att uppnå sina mål. Studien består av semistrukturerade intervjuer med en grupp elever på högstadiet som läser svenska som andraspråk i skolan och det var både flickor och pojkar som deltog. De berörda eleverna talar svenska som andraspråk. I uppsatsen har även en grupp kemilärare på högstadiet intervjuats. Vi diskuterade de viktigaste undervisningsmetoderna som används för att stödja utvecklingen hos flerspråkiga elever för att nå målet. Detta gjordes genom att involvera eleverna i lösningen genom att presentera sina åsikter och idéer om undervisningsprocessen.Resultaten som framkom visar att eleverna har svårt att hantera vetenskapliga texter, nya begrepp och abstrakta ord. Det kan naturligtvis vara svårt eller abstrakt med vetenskapliga uttryck även när de använder sitt modersmål. Lärarna strävar efter att använda en lämplig arbetsmetod som utgår från flerspråkiga elevers modersmål, vardagsspråk och förkunskaper för att kommunicera kemiämnet.För att stödja flerspråkiga elever bör lärarna fokusera på både ämnesspråket och vardagsspråket i sin undervisning.

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  • 3.
    Adbo, Karina
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    Constructing the chemical bond concept2012In: Nankai University, 2012Conference paper (Other (popular science, discussion, etc.))
  • 4.
    Adbo, Karina
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    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.

  • 5.
    Adbo, Karina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Kinetics of enantioselective solid-phase extraction on Trager's base molecularly imprinted polymers, in: Molecularly imprinted polymer science and technology2000Conference paper (Refereed)
  • 6.
    Adbo, Karina
    Linnéuniversitetet, Institutionen för naturvetenskap, NV.
    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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  • 7.
    Adbo, Karina
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Andersson, Håkan S.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Ankarloo, Jonas
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Karlsson, Jesper G.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Norell, M C
    Olofsson, Linus
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Svenson, Johan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Örtegren, U
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Enantioselective synthetic receptors for Tröger’s base1999In: Bioorganic Chemistry, Vol. 27, no 5, p. 363-371Article in journal (Refereed)
  • 8.
    Adbo, Karina
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Enantioselective SPE on Tröger 's base molecularly imprinted polymers2001Conference paper (Refereed)
  • 9.
    Adbo, Karina
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian Alan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Enantioselective SPE on Tröger’s base molecularly imprinted polymers2001Conference paper (Refereed)
  • 10.
    Adbo, Karina
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian Alan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Study of the kinetics of enantioselective solid-phase extraction on Tröger’s base molecularly imprinted polymers2001In: Analytica Chimica Acta, Vol. 435, p. 115-120Article in journal (Refereed)
  • 11.
    Adbo, Karina
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian Alan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Kinetics of enantioselective solid-phase extraction of Tröger’s base molecularly imprinted polymers2000Conference paper (Refereed)
  • 12.
    Adbo, Karina
    et al.
    Linnéuniversitetet, Institutionen för utbildningsvetenskap (UV).
    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.

  • 13.
    Adbo, Karina
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Vidal Carulla, Clara
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    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.

  • 14.
    Adbo, Karina
    et al.
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    Vidal Carulla, Clara
    Linnéuniversitetet, Institutionen för biologi och miljö (BOM).
    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.

  • 15.
    Albertin, S.
    et al.
    Lund Univ, Div Synchrotron Radiat Res, Box 118, S-22100 Lund, Sweden..
    Gustafson, J.
    Lund Univ, Div Synchrotron Radiat Res, Box 118, S-22100 Lund, Sweden..
    Zhou, J.
    Lund Univ, Div Combust Phys, SE-22100 Lund, Sweden..
    Pfaff, S.
    Lund Univ, Div Combust Phys, SE-22100 Lund, Sweden..
    Shipilin, M.
    Stockholm Univ, Div Phys Chem, SE-10691 Stockholm, Sweden..
    Blomberg, S.
    Lund Univ, Dept Chem Engn, SE-22100 Lund, Sweden..
    Merte, Lindsay R.
    Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM).
    Gutowski, O.
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Dippel, A-C
    Deutsch Elektronen Synchrotron DESY, D-22607 Hamburg, Germany..
    Zetterberg, J.
    Lund Univ, Div Combust Phys, SE-22100 Lund, Sweden..
    Lundgren, E.
    Lund Univ, Div Synchrotron Radiat Res, Box 118, S-22100 Lund, Sweden..
    Hejral, U.
    Lund Univ, Div Synchrotron Radiat Res, Box 118, S-22100 Lund, Sweden..
    Surface optical reflectance combined with x-ray techniques during gas-surface interactions2020In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 53, no 22, article id 224001Article in journal (Refereed)
    Abstract [en]

    High energy surface x-ray diffraction (HESXRD), x-ray reflectivity (XRR), mass spectrometry (MS) and surface optical reflectance (SOR) have been combined to simultaneously obtain sub-second information on the surface structure and morphology from a Pd(100) model catalyst during in situ oxidation at elevated temperatures and pressures resulting in Pd bulk oxide formation. The results show a strong correlation between the HESXRD and SOR signal intensities during the experiment, enabling phase determination and a time-resolved thickness estimation of the oxide by HESXRD, complemented by XRR measurements. The experiments show a remarkable sensitivity of the SOR to changes in the surface phase and morphology, in particular to the initial stages of oxidation/reduction. The data imply that SOR can detect the formation of an ultrathin PdO surface oxide layer of only 2-3 angstrom thickness.

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  • 16.
    Albertin, Stefano
    et al.
    Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden.
    Merte, Lindsay R.
    Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM).
    Lundgren, Edvin
    Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden.
    Martin, Rachel
    Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States.
    Weaver, Jason F.
    Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611, United States.
    Dippel, Ann-Christin
    Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany.
    Gutowski, Olof
    Deutsches Elektronen-Synchrotron (DESY), 22603 Hamburg, Germany.
    Hejral, Uta
    Division of Synchrotron Radiation Research, Lund University, SE-22100 Lund, Sweden.
    Oxidation and Reduction of Ir(100) Studied by High-Energy Surface X-ray Diffraction2022In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 126, no 11, p. 5244-5255Article in journal (Refereed)
    Abstract [en]

    The oxidation and reduction of an Ir(100) surface using 2.5, 5, and 10 mbar O2 partial pressure and a sample temperature of 775 K have been studied by using high-energy surface X-ray diffraction (HESXRD) which allowed to record large volumes of reciprocal space in short time periods. The complex 3D diffraction patterns could be disentangled in a stepwise procedure. For the 2.5mbar experiment the measurements indicate the formation of an Ir(100)-O c(2 × 2) oxygen superstructure along with the onset of epitaxial IrO2(110) bulk oxide formation. For the 5 and 10 mbar O2 partial pressures the formation of additional IrO2 bulk oxide epitaxies with (100) and (101) orientations as well as of polycrystalline IrO2 was observed. Upon CO reduction, we found the IrO2 islands to be reduced into epitaxial and metallic Ir(111) and (221) oriented islands.

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  • 17.
    Aleksejeva, Olga
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nilsson, Nicklas
    Obducat Technol AB, S-22363 Lund, Sweden..
    Genevskiy, Vladislav
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Thulin, Kristian
    Obducat Technol AB, S-22363 Lund, Sweden..
    Shleev, Sergey
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Photobioanodes Based on Nanoimprinted Electrodes and Immobilized Chloroplasts2022In: ChemElectroChem, E-ISSN 2196-0216, Vol. 9, no 2, p. 37-42Article in journal (Refereed)
    Abstract [en]

    As the global energy demand continues to increase, the interest in photosynthetic energy conversion is growing accordingly. Chloroplasts, photosynthetic organelles present in plants and algae, are attractive candidates for construction of bio solar cells; however, they have been less studied because of their complex membrane system, which restricts electrochemical communication with an electrode surface. Nevertheless, in this work photobioanodes based on planar and nanoimprinted gold substrates modified with chloroplasts were designed and evaluated. Apparently, nanoimprint lithography contributed to higher photocurrent densities, not only owing to the enlarged real surface area, but also due to boosting electrochemical communication between the photosynthetic organelles and the electrode. Combining chloroplast-modified nanoimprinted gold electrodes with a capacitive part made of a planar gold substrate, coated with a conductive polymer, resulted in a dual-feature photobioanode providing a lower open-circuit potential, i. e., -0.11 V vs. Ag|AgCl|KClsat, and an enhanced capacitance of ca. 37 F m(-2) upon illumination of 400 W m(-2).

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  • 18.
    Aleksejeva, Olga
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Sokolov, A. V.
    Russia Saint-Petersburg State University, Russia.
    Marquez, I.
    University of Seville, Spain.
    Gustafsson, Anna
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Bushnev, S.
    Russian Academy of Sciences, Russia.
    Eriksson, Håkan
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Ljunggren, Lennart
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Shleev, Sergey
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Russian Academy of Sciences, Russia.
    Autotolerant ceruloplasmin based biocathodes for implanted biological power sources2021In: Bioelectrochemistry, ISSN 1567-5394, E-ISSN 1878-562X, Vol. 140Article in journal (Refereed)
    Abstract [en]

    High-performance autotolerant bioelectrodes should be ideally suited to design implantable bioelectronic devices. Because of its high redox potential and ability to reduce oxygen directly to water, human ceruloplasmin, HCp, the only blue multicopper oxidase present in human plasma, appears to be the ultimate biocatalyst for oxygen biosensors and also biocathodes in biological power sources. In comparison to fungal and plant blue multicopper oxidases, e.g. Myrothecium verrucaria bilirubin oxidase and Rhus vernicifera laccase, respectively, the inflammatory response to HCp in human blood is significantly reduced. Partial purification of HCp allowed to preserve the native conformation of the enzyme and its biocatalytic activity. Therefore, electrochemical studies were carried out with the partially purified enzyme immobilised on nanostructured graphite electrodes at physiological pH and temperature. Amperometric investigations revealed low reductive current densities, i.e. about 1.65 µA cm−2 in oxygenated electrolyte and in the absence of any mediator, demonstrating nevertheless direct electron transfer based O2 bioelectroreduction by HCp for the first time. The reductive current density obtained in the mediated system was about 12 µA cm−2. Even though the inflammatory response of HCp is diminished in human blood, inadequate bioelectrocatalytic performance hinders its use as a cathodic bioelement in a biofuel cell.

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  • 19.
    Ambaw, Y. A.
    et al.
    Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore; Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Harvard University, Cambridge, MA 02138, USA.
    Dahl, S. R.
    Department of Chemistry, University of Oslo, 0315 Oslo, Norway; Hormone Laboratory, Department of Medical Biochemistry, Oslo University Hospital, 0424 Oslo, Norway.
    Chen, Y.
    Department of Chemistry, University of Oslo, 0315 Oslo, Norway.
    Greibrokk, T.
    Department of Chemistry, University of Oslo, 0315 Oslo, Norway.
    Lundanes, E.
    Department of Chemistry, University of Oslo, 0315 Oslo, Norway.
    Lazraq, Issam
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Shinde, Sudhirkumar
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. School of Consciousness, Dr Vishwanath Karad Maharashtra Institute of Technology–World Peace University, Kothrud, Pune 411038, Maharashtra, India.
    Selvalatchmanan, J.
    Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore.
    Wenk, M. R.
    Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore.
    Sellergren, Börje
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Torta, F.
    Precision Medicine Translational Research Programme and Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore; SLING, Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore.
    Tailored polymer-based selective extraction of lipid mediators from biological samples2021In: Metabolites, ISSN 2218-1989, E-ISSN 2218-1989, Vol. 11, no 8, article id 539Article in journal (Refereed)
    Abstract [en]

    Lipid mediators, small molecules involved in regulating inflammation and its resolution, are a class of lipids of wide interest as their levels in blood and tissues may be used to monitor health and disease states or the effect of new treatments. These molecules are present at low levels in biological samples, and an enrichment step is often needed for their detection. We describe a rapid and selective method that uses new low-cost molecularly imprinted (MIP) and non-imprinted (NIP) polymeric sorbents for the extraction of lipid mediators from plasma and tissue samples. The extraction process was carried out in solid-phase extraction (SPE) cartridges, manually packed with the sorbents. After extraction, lipid mediators were quantified by liquid chromatography–tandem mass spectrometry (LC–MSMS). Various parameters affecting the extraction efficiency were evaluated to achieve optimal recovery and to reduce non-specific interactions. Preliminary tests showed that MIPs, designed using the prostaglandin biosynthetic precursor arachidonic acid, could effectively enrich prostaglandins and structurally related molecules. However, for other lipid mediators, MIP and NIP displayed comparable recoveries. Under optimized conditions, the recoveries of synthetic standards ranged from 62% to 100%. This new extraction method was applied to the determination of the lipid mediators concentration in human plasma and mouse tissues and compared to other methods based on commercially available cartridges. In general, the methods showed comparable performances. In terms of structural specificity, our newly synthesized materials accomplished better retention of prostaglandins (PGs), hydroxydocosahexaenoic acid (HDoHE), HEPE, hydroxyeicosatetraenoic acids (HETE), hydroxyeicosatrienoic acid (HETrE), and PUFA compounds, while the commercially available Strata-X showed a higher recovery for dihydroxyeicosatetraenoic acid (diHETrEs). In summary, our results suggest that this new material can be successfully implemented for the extraction of lipid mediators from biological samples. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

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  • 20. Andoralov, Viktor
    et al.
    Shleev, Sergey
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Arnebrant, Thomas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Ruzgas, Tautgirdas
    Malmö högskola, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Flexible micro(bio)sensors for quantitative analysis of bioanalytes in a nanovolume of human lachrymal liquid2013In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 405, no 11, p. 3871-3879Article in journal (Refereed)
    Abstract [en]

    A flexible electrochemical micro(bio)sensor has been designed for determination of several biological compounds, specifically, ascorbate, dopamine, and glucose, in human lachrymal liquid (tears). The microsensor for simultaneous determination of ascorbate and dopamine concentrations was based on a gold microwire modified with the tetrathiafulvalen–7,7,8,8-tetracyanoquinodimethane complex as a catalyst. To monitor glucose concentration in tears, glucose dehydrogenase was immobilized on a gold microwire modified with carbon nanotubes and an osmium redox polymer. A capillary microcell was constructed for sampling tears. The cell had a working volume of 60–100 nL with a sampling deviation of 6.7 %. To check if the microcell was properly filled with buffer or tear sample, a control electrode was introduced into the construction. The electrode was used to measure the electrical resistance of a fully filled nanovolume cell. The mechanical flexibility is one of the most important features of the prototype and allowed direct collection of tears with minimized risk of damage to the eye.

  • 21.
    Argatov, Ivan
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Institut für Mechanik, Technische Universität Berlin, 10623 Berlin, Germany.
    Engblom, Johan
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Modeling of composite sorption isotherm for stratum corneum2022In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1864, no 7, p. 1-8, article id 183910Article in journal (Refereed)
    Abstract [en]

    Equilibrium water sorption in stratum corneum (SC) is considered by treating it as a biocomposite with two main phases, namely, corneocytes and lipids. To validate the rule of mixtures for the individual phase sorption isotherms, a new flexible fitting model is introduced by accounting for characteristic features observed in the variations of the thermodynamic correction factors corresponding to the individual sorption isotherms. The comparison of the model fitting performance with that of the five-parameter Park's model shows a remarkably good ability to fit experimental data for different types of sorption isotherms. The effect of the lipids content on the variance of the composite sorption isotherm of stratum corneum is highlighted. The sensitivity analysis reveals that for the typical water content 20-30 wt%, which corresponds to the SC in a stable condition, the sensitivity of the composite sorption isotherm to the variation of the lipids content on dry basis is predominantly positive and sufficiently small. The good agreement observed between the experimental sorption isotherm for SC and the composite isotherm, which is based on the rule of mixtures for the individual phase sorption isotherms, yields a plausible conclusion (hypothesis) that the corneocytes-lipids mechanical interaction during unconstrained swelling of the SC membrane in the in vitro laboratory experiment is negligible.

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  • 22.
    Argatov, Ivan
    et al.
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Chongqing University, China.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    An empirical model for sorption by glassy polymers: An assessment of thermodynamic parameters2021In: Polymer testing, ISSN 0142-9418, E-ISSN 1873-2348, Vol. 99Article in journal (Refereed)
    Abstract [en]

    A new fitting model for sorption by glassy polymers is suggested based on the Flory–Huggins (FH) equation with a composite formula for the FH interaction parameter, χ, which is applicable if sorption experimental data shows a single-maximum variation of the FH parameter. Namely, a power-like and a linear approximation is assumed for χ(φ1), as a function of solvent volume fraction φ1, before and after the point of its maximum. After determining the maximum point from a direct inspection of the sorption data, the three fitting parameters are evaluated by solving two independent least-square minimization problems. Several sorption studies of biopolymers taken from the literature show that the endset of the glass transition region is correlated with the position of the maximum of the FH interaction parameter. Based on this hypothesis and the Vrentas–Vrentas model for sorption of glassy polymers, a theoretical framework for the glass transition analysis is developed. In particular, the solvent-induced glass transition temperature variation can be estimated from the sorption isotherm as a function of the solvent content corresponding to temperatures above the temperature of sorption.

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  • 23.
    Argatov, Ivan
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Tech Univ Berlin, Inst Mech, D-10623 Berlin, Germany..
    Roosen-Runge, Felix
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Dynamics of post-occlusion water diffusion in stratum corneum2022In: Scientific Reports, E-ISSN 2045-2322, Vol. 12, no 1, article id 17957Article in journal (Refereed)
    Abstract [en]

    Diffusion of water through membranes presents a considerable challenge, as the diffusivity often depends on the local concentration of water. One particular example with strong biological relevance is the stratum corneum (SC) as the primary permeability barrier for the skin. A simple alternative for the constant diffusivity model is provided by the Fujita's two-parameter rational approximation, which captures the experimentally observed fact that the SC diffusion constant for water increases with increasing the water concentration. Based on Fick's law of diffusion, a one-dimensional concentration-dependent diffusion model is developed and applied for the analysis of both the steady-state transepidermal water loss (TEWL) and the non-steady-state so-called skin surface water loss (SSWL) occurred after removal of an occlusion patch from the SC surface. It is shown that some of the age-related changes in the SSWL can be qualitatively explained by the variation of the dimensionless Fujita concentration-dependence parameter.

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  • 24.
    Asplund, Karin
    et al.
    Malmö University, Faculty of Education and Society (LS), Department of Natural Science, Mathematics and Society (NMS).
    Karlsson, Martin
    Malmö University, Faculty of Education and Society (LS), Department of Natural Science, Mathematics and Society (NMS).
    Hur upplever elever olika läroboksupplägg?2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Det finns mycket forskning kring läroböckers upplägg, men inte ur ett elevperspektiv. Syftet med den här studien är därför att undersöka vem eleven är i ett kemididaktiskt perspektiv i relation till olika läroboksupplägg. Studien tar sin utgångspunkt från lärobokens multimodala utformning och metoden ”Motivationsstrategier för inlärning” som kan kopplas till bokens utformning, dess övningsuppgifter och extramaterial. Genom analys av läroböcker, enkätstudie med slutna och öppna frågor samt semistrukturerade intervjuer av gymnasieelever som läser naturvetenskapliga programmet karaktäriseras hur elever upplever olika läroboksupplägg. Resultatet visar att elever kan ha helt olika upplevelse av samma lärobok och främst saknar nivåindelade övningsuppgifter i läroböcker och extramaterial. Vad läraren tar med på proven avgör vilka delar av läroboken som eleverna prioriterar. Slutsatsen från studien är att ingen lärobok uppfyller alla elevers behov eftersom olika elever tolkar kemins förenkling av verkligheten via text och bild på olika sätt. Därför blir det viktigt att läraren kompenserar för lärobokens begränsningar genom att presentera samma fenomen med andra förklaringsmodeller.

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  • 25.
    Banan, Kamran
    et al.
    Shahid Beheshti Univ Med Sci, Sch Pharm, Dept Pharmaceut, Tehran, Iran..
    Ghorbani-Bidkorbeh, Fatemeh
    Shahid Beheshti Univ Med Sci, Sch Pharm, Dept Pharmaceut, Tehran, Iran..
    Afsharara, Hanif
    Shahid Beheshti Univ Med Sci, Sch Pharm, Dept Med Chem, Tehran, Iran..
    Hatamabadi, Dara
    Shahid Beheshti Univ Med Sci, Sch Pharm, Dept Med Chem, Tehran, Iran..
    Landi, Behnaz
    Shahid Beheshti Univ Med Sci, Sch Pharm, Dept Pharmaceut, Tehran, Iran..
    Kecili, Rustem
    Anadolu Univ, Yunus Emre Vocat Sch Hlth Serv, Dept Med Serv & Tech, Eskisehir, Turkey..
    Sellergren, Börje
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Nano-sized magnetic core-shell and bulk molecularly imprinted polymers for selective extraction of amiodarone from human plasma2022In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 1198, article id 339548Article in journal (Refereed)
    Abstract [en]

    Bulk and magnetic core-shell Molecularly Imprinted Polymers (MMIPs) have been introduced and compared to extract and determine amiodarone from a complex matrix, i.e., plasma, due to the importance of Therapeutic Drug Monitoring (TDM). Polymer synthesis was confirmed by FTIR, AFM, TGA, DLS, VSM, TEM, and the adsorption studies such as capacity, isothermal models, selectivity, and regeneration were performed to evaluate and compare polymer efficiency in extraction and separation of amiodarone from sample solutions and human plasma. Both nano-sized and bulk polymers successfully extracted the target molecule at the low therapeutic ranges and the overdose concentrations (recoveries of 98.38%-102.70%). The maximum adsorption capacity of the MMIPs was 42.5 mu g/mg compared with 2.6 mu g/mg for bulk polymers. The imprinting factors of the polymers were 15.12 and 6.84 for MMIPs and bulk, respectively. MMIPs and bulk polymers presented 4.68 and 1.66 selectivity factors, respectively, towards amiodarone compared with lidocaine. LOD, LOQ and enrichment factor in human plasma were 0.09, 0.28 mu g mL(-1), and 10 respectively. Recoveries of therapeutic concentration from plasma were 91.38 and 97.33% for bulk and MMIPs, respectively. MMIPs as an adsorbent in amiodarone extraction from plasma offered reduced necessary sample amount, less adsorbent consumption, reduced pretreatment time, and reduced elution solvent waste while yielding higher extraction recovery and more specificity for the target compared with the bulk polymer. Bulk polymers have a more straightforward synthesis procedure due to fewer synthesis steps and fewer variables, and Molecularly Imprinted Polymer Solid-phase Extraction (MIP-SPE) has already been introduced commercially. MMIPs prevail on a small scale, and in the context of a simple extraction, separation, or concentration in large-scale bioanalysis, efforts towards optimization and development of MMIPs can unearth tremendous opportunities for green chemistry principles. 

  • 26.
    Beck, Christian
    et al.
    Univ Tubingen, Inst Angew Phys, Morgenstelle 10, D-72076 Tubingen, Germany.;Inst Max von Laue Paul Langevin, 71 Ave Martyrs, F-38042 Grenoble, France..
    Grimaldo, Marco
    Inst Max von Laue Paul Langevin, 71 Ave Martyrs, F-38042 Grenoble, France..
    Braun, Michal K.
    Univ Tubingen, Inst Angew Phys, Morgenstelle 10, D-72076 Tubingen, Germany..
    Buhl, Lena
    Univ Tubingen, Inst Angew Phys, Morgenstelle 10, D-72076 Tubingen, Germany..
    Matsarskaia, Olga
    Inst Max von Laue Paul Langevin, 71 Ave Martyrs, F-38042 Grenoble, France..
    Jalarvo, Niina H.
    Forschungszentrum Julich, Julich Ctr Neutron Sci JCNS, D-52425 Julich, Germany.;Oak Ridge Natl Lab, Chem & Engn Mat Div, Neutron Sci Directorate, POB 2008, Oak Ridge, TN 37831 USA.;Oak Ridge Natl Lab, JCNS Outstn Spallat Neutron Source SNS, POB 2008, Oak Ridge, TN 37831 USA..
    Zhang, Fajun
    Univ Tubingen, Inst Angew Phys, Morgenstelle 10, D-72076 Tubingen, Germany..
    Roosen-Runge, Felix
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Lund Univ, Div Phys Chem, Nat Vetarvagen 14, S-22100 Lund, Sweden..
    Schreiber, Frank
    Univ Tubingen, Inst Angew Phys, Morgenstelle 10, D-72076 Tubingen, Germany..
    Seydel, Tilo
    Inst Max von Laue Paul Langevin, 71 Ave Martyrs, F-38042 Grenoble, France..
    Temperature and salt controlled tuning of protein clusters2021In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, no 37, p. 8506-8516Article in journal (Refereed)
    Abstract [en]

    The formation of molecular assemblies in protein solutions is of strong interest both from a fundamental viewpoint and for biomedical applications. While ordered and desired protein assemblies are indispensable for some biological functions, undesired protein condensation can induce serious diseases. As a common cofactor, the presence of salt ions is essential for some biological processes involving proteins, and in aqueous suspensions of proteins can also give rise to complex phase diagrams including homogeneous solutions, large aggregates, and dissolution regimes. Here, we systematically study the cluster formation approaching the phase separation in aqueous solutions of the globular protein BSA as a function of temperature (T), the protein concentration (c(p)) and the concentrations of the trivalent salts YCl3 and LaCl3 (c(s)). As an important complement to structural, i.e. time-averaged, techniques we employ a dynamical technique that can detect clusters even when they are transient on the order of a few nanoseconds. By employing incoherent neutron spectroscopy, we unambiguously determine the short-time self-diffusion of the protein clusters depending on c(p), c(s) and T. We determine the cluster size in terms of effective hydrodynamic radii as manifested by the cluster center-of-mass diffusion coefficients D. For both salts, we find a simple functional form D(c(p), c(s), T) in the parameter range explored. The calculated inter-particle attraction strength, determined from the microscopic and short-time diffusive properties of the samples, increases with salt concentration and temperature in the regime investigated and can be linked to the macroscopic behavior of the samples.

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  • 27.
    Beck, Christian
    et al.
    Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany; Institut Max von Laue Paul Langevin (ILL), CS 20156, F-38042 Grenoble Cedex 9, France..
    Pounot, Kevin
    Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany; Institut Max von Laue Paul Langevin (ILL), CS 20156, F-38042 Grenoble Cedex 9, France..
    Mosca, Ilaria
    Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany; Institut Max von Laue Paul Langevin (ILL), CS 20156, F-38042 Grenoble Cedex 9, France..
    H Jalarvo, Niina
    Jülich Centre for Neutron Science (JCNS), Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany; Chemical and Engineering Materials Division, Neutron Sciences Directorate, and JCNS Outstation at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, USA.
    Roosen-Runge, Felix
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Schreiber, Frank
    Institut für Angewandte Physik, Universität Tübingen, Auf der Morgenstelle 10, 72076 Tübingen, Germany.
    Seydel, Tilo
    Institut Max von Laue Paul Langevin (ILL), CS 20156, F-38042 Grenoble Cedex 9, France.
    Notes on Fitting and Analysis Frameworks for QENS Spectra of (Soft) Colloid Suspensions2022In: EPJ Web of Conferences, E-ISSN 2100-014X, Vol. 272, p. 01004-01004Article in journal (Refereed)
    Abstract [en]

    With continuously improving signal-to-noise ratios, a statistically sound analysis of quasi-elasticneutron scattering (QENS) spectra requires to fit increasingly complex models which poses several challenges.Simultaneous fits of the spectra for all recorded values of the momentum transfer become a standard approach.Spectrometers at spallation sources can have a complicated non-Gaussian resolution function which has to bedescribed most accurately. At the same time, to speed up the fitting, an analytical convolution with this resolutionfunction is of interest. Here, we discuss basic concepts to efficient approaches for fits of QENS spectra basedon standard MATLAB and Python fit algorithms. We illustrate the fits with example data from IN16B, BASIS,and BATS.

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  • 28.
    Bogdanova, Ekaterina
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. NextBioForm Competence Centre, Stockholm, Sweden.
    Fureby, Anna Millqvist
    RISE Research Institutes of Sweden, Stockholm, Sweden; NextBioForm Competence Centre, Stockholm, Sweden.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. NextBioForm Competence Centre, Stockholm, Sweden.
    Influence of cooling rate on ice crystallization and melting in sucrose-water system2022In: Journal of Pharmaceutical Sciences, ISSN 0022-3549, E-ISSN 1520-6017, Vol. 111, no 7, p. 2030-2037, article id S0022-3549(22)00035-1Article in journal (Refereed)
    Abstract [en]

    The ice crystallization and melting in systems where the equilibrium state is difficult to reach is one of the growing areas in pharmaceutical freeze-drying research. The quality of the final freeze-dried product depends on the parameters of the cooling step, which affect the ice nucleation and growth. In this paper, we present a DSC study of ice crystallization and melting in a sucrose-water system. Using two different types of thermal cycles, we examine the influence of cooling and heating rates on the thermal behavior of sucrose-water solutions with water contents between 50 and 100 wt%.

    The DSC results show that low cooling rates provide crystallization at higher temperatures and lead to lower amount of nonfreezing water. Consequently, the glass transition and ice melting properties observed upon heating depend on the cooling conditions in the preceding step. Based on the experimental results, we investigate the reasons for the existence of the two steps on DSC heating curves in sucrose-water systems: the glass transition step and the onset of ice melting. We show that diffusion of water can be the limiting factor for ice growth and melting in the sucrose-water system when the amorphous phase is in a liquid state. In particular, when the diffusion coefficient drops below 10−14 m2/sec, the ice crystals growth or melting becomes strongly suppressed even above the glass transition temperature. Understanding the diffusion limitations in the sucrose-water system can be used for the optimization of the freeze-drying protocols for proteins and probiotics.

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  • 29.
    Bogdanova, Ekaterina
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Lages, Sebastian
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. MAX IV Laboratory, Lund University, Lund SE-22484, Sweden.
    Phan-Xuan, Tuan
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. MAX IV Laboratory, Lund University, Lund SE-22484, Sweden.
    Kamal, Md Arif
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Division of Physical Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden.
    Terry, Ann
    MAX IV Laboratory, Lund University, Lund SE-22484, Sweden.
    Millqvist Fureby, Anna
    RISE Research Institutes of Sweden, Stockholm SE-114 86, Sweden.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Lysozyme-Sucrose Interactions in the Solid State: Glass Transition, Denaturation, and the Effect of Residual Water.2023In: Molecular Pharmaceutics, ISSN 1543-8384, E-ISSN 1543-8392, Vol. 20, no 9, p. 4664-4675Article in journal (Refereed)
    Abstract [en]

    The freeze-drying of proteins, along with excipients, offers a solution for increasing the shelf-life of protein pharmaceuticals. Using differential scanning calorimetry, thermogravimetric analysis, sorption calorimetry, and synchrotron small-angle X-ray scattering (SAXS), we have characterized the properties at low (re)hydration levels of the protein lysozyme, which was freeze-dried together with the excipient sucrose. We observe that the residual moisture content in these samples increases with the addition of lysozyme. This results from an increase in equilibrium water content with lysozyme concentration at constant water activity. Furthermore, we also observed an increase in the glass transition temperature (Tg) of the mixtures with increasing lysozyme concentration. Analysis of the heat capacity step of the mixtures indicates that lysozyme does not participate in the glass transition of the sucrose matrix; as a result, the observed increase in the Tg of the mixtures is the consequence of the confinement of the amorphous sucrose domains in the interstitial space between the lysozyme molecules. Sorption calorimetry experiments demonstrate that the hydration behavior of this formulation is similar to that of the pure amorphous sucrose, while the presence of lysozyme only shifts the sucrose transitions. SAXS analysis of amorphous lysozyme–sucrose mixtures and unfolding of lysozyme in this environment show that prior to unfolding, the size and shape of lysozyme in a solid sucrose matrix are consistent with its native state in an aqueous solution. The results obtained from our study will provide a better understanding of the low hydration behavior of protein–excipient mixtures and support the improved formulation of biologics.

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  • 30.
    Bogdanova, Ekaterina
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Millqvist Fureby, Anna
    RISE Research Institutes of Sweden.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Hydration enthalpies of amorphous sucrose, trehalose and maltodextrins and their relationship with heat capacities2021In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, no 26, p. 14433-14448Article in journal (Refereed)
    Abstract [en]

    The mechanisms of glass transitions and the behavior of small solute molecules in a glassy matrix are some of the most important topics of modern thermodynamics. Water plays an important role in the physical and chemical stability of lyophilized biologics formulations, in which glassy carbohydrates act as cryoprotectants and stabilizers. In this study, sorption calorimetry was used for simultaneous measurements of water activity and the enthalpy of water sorption by amorphous sucrose, trehalose and maltodextrins. Moreover, the heat capacity of these carbohydrates in mixtures with water was measured by DSC in a broad range of water contents. The hydration enthalpies of glassy sucrose, trehalose and maltodextrins are exothermic, and the enthalpy change of water-induced isothermal glass transitions is higher for small molecules. The partial molar enthalpy of mixing of water in slow experiments is about -18 kJ mol-1, but less exothermic in the case of small molecules at fast hydration scan rates. By measuring the heat capacities of disaccharides and maltodextrins as a function of water content, we separated the contributions of carbohydrates and water to the total heat capacities of the mixtures. The combination of these data allowed testing of thermodynamic models describing the hydration-induced glass transitions. The heat capacity changes calculated by the fitting of the hydration enthalpy data for disaccharides are in good agreement with the heat capacity data obtained by DSC, while for maltodextrins, the effect of sub-Tg transitions should be taken into account. Combining the data obtained by different techniques, we found a distinct difference in the behavior of water in glassy polymers compared to that in glassy disaccharides. By understanding the behavior of water in glassy carbohydrates, these results can be used to improve the design of freeze-dried formulations of proteins and probiotics.

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  • 31.
    Boyd, Hannah
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Gonzalez-Martinez, Juan F
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Welbourn, Rebecca J L
    Rutherford Appleton Laboratory, UK.
    Ma, Kun
    Rutherford Appleton Laboratory, UK.
    Li, Peixun
    Rutherford Appleton Laboratory, UK.
    Gutfreund, Philipp
    Institut Laue Langevin, France.
    Klechikov, Alexey
    Institut Laue Langevin, France; Uppsala University.
    Arnebrant, Thomas
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Barker, Robert
    University of Kent, UK.
    Sotres, Javier
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Effect of nonionic and amphoteric surfactants on salivary pellicles reconstituted in vitro2021In: Scientific Reports, E-ISSN 2045-2322, Vol. 11, no 1, article id 12913Article in journal (Refereed)
    Abstract [en]

    Surfactants are important components of oral care products. Sodium dodecyl sulfate (SDS) is the most common because of its foaming properties, taste and low cost. However, the use of ionic surfactants, especially SDS, is related to several oral mucosa conditions. Thus, there is a high interest in using non-ionic and amphoteric surfactants as they are less irritant. To better understand the performance of these surfactants in oral care products, we investigated their interaction with salivary pellicles i.e., the proteinaceous films that cover surfaces exposed to saliva. Specifically, we focused on pentaethylene glycol monododecyl ether (C12E5) and cocamidopropyl betaine (CAPB) as model nonionic and amphoteric surfactants respectively, and investigated their interaction with reconstituted salivary pellicles with various surface techniques: Quartz Crystal Microbalance with Dissipation, Ellipsometry, Force Spectroscopy and Neutron Reflectometry. Both C12E5 and CAPB were gentler on pellicles than SDS, removing a lower amount. However, their interaction with pellicles differed. Our work indicates that CAPB would mainly interact with the mucin components of pellicles, leading to collapse and dehydration. In contrast, exposure to C12E5 had a minimal effect on the pellicles, mainly resulting in the replacement/solubilisation of some of the components anchoring pellicles to their substrate.

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  • 32.
    Braud, N.
    et al.
    Univ Bremen, Inst Solid State Phys, Otto Hahn Allee 1, D-28359 Bremen, Germany..
    Buss, L.
    Brandenburg Univ Technol Cottbus Senftenberg, Appl Phys & Semicond Spect, K Zuse Str 1, D-03046 Cottbus, Germany..
    Lundgren, E.
    Lund Univ, Div Synchrotron Radiat Res, S-22100 Lund, Sweden..
    Merte, L. R.
    Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM).
    Wallander, H.
    Malmö University, Faculty of Technology and Society (TS), Department of Materials Science and Applied Mathematics (MTM).
    Krisponeit, J. -O
    Univ Bremen, Inst Solid State Phys, Otto Hahn Allee 1, D-28359 Bremen, Germany.;Univ Bremen, MAPEX Ctr Mat & Proc, D-28359 Bremen, Germany..
    Locatelli, A.
    Elettra Sincrotrone Trieste SCpA, SS 14,Km 163-5 Area Sci Pk, I-34149 Trieste, Italy..
    Mentes, T. O.
    Elettra Sincrotrone Trieste SCpA, SS 14,Km 163-5 Area Sci Pk, I-34149 Trieste, Italy..
    Jugovac, M.
    Elettra Sincrotrone Trieste SCpA, SS 14,Km 163-5 Area Sci Pk, I-34149 Trieste, Italy..
    Flege, J. I.
    Brandenburg Univ Technol Cottbus Senftenberg, Appl Phys & Semicond Spect, K Zuse Str 1, D-03046 Cottbus, Germany..
    Falta, J.
    Univ Bremen, Inst Solid State Phys, Otto Hahn Allee 1, D-28359 Bremen, Germany.;Univ Bremen, MAPEX Ctr Mat & Proc, D-28359 Bremen, Germany..
    Cleaning and tailoring the Pt3Sn(111) surface for surface experiments2023In: Surface Science, ISSN 0039-6028, E-ISSN 1879-2758, Vol. 732, article id 122281Article in journal (Refereed)
    Abstract [en]

    The cleaning process of the bimetallic Pt3Sn(111) surface has been studied by means of low-energy electron microscopy (LEEM), microspot low-energy electron diffraction (mu.-LEED), and X-ray photoemission electron microscopy (XPEEM). Different cleaning procedures, performed under ultra-high vacuum conditions (UHV), including sputtering with argon ions and repeated cycles of annealing up to 1500 K were investigated. In this work, we show that a clean Pt3Sn(111) surface of high structural quality with a sharp and brilliant (2 x 2) bulk reconstruction in LEED as well as a perfectly smooth surface with terraces of micron size can be achieved by sputtering, annealing at very high temperatures, followed by a subsequent slow (0.09 K/s) and careful cooling procedure. Additionally, we show the possibility of tailoring the Sn concentration in the topmost layers of Pt3Sn(111) as a function of annealing temperature and subsequent cooling rate. Structural changes of the surface are induced by Sn segregation combined with a surface order-disorder transition at 1340 K. Moreover, two new surface reconstructions depending on the cooling rate are reported.

  • 33.
    Bäcklund, Frida
    et al.
    Malmö University, Faculty of Education and Society (LS), Department of Natural Science, Mathematics and Society (NMS).
    Elin, Kullberg
    Malmö University, Faculty of Education and Society (LS), Department of Natural Science, Mathematics and Society (NMS).
    Utomhuspedagogik i kemiämnet2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
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  • 34. Cao, Cheng
    et al.
    Chen, Fan
    Garvey, Christopher J.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Stenzel, Martina H
    Drug-Directed Morphology Changes in Polymerization-Induced Self-Assembly (PISA) Influence the Biological Behavior of Nanoparticles2020In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 12, no 27, p. 30221-30233Article in journal (Refereed)
    Abstract [en]

    The effect of the hydrophobic block length on the morphologies of polymerization-induced self-assembled (PISA) nanoparticles is well understood. However, the influence of drug loading on the phase morphology of the nanoparticles during the PISA process, and the resulting biological function of PISA nanoparticles, has barely been investigated. In this work, we show that the addition of a drug, curcumin, during the PISA process shifts the phase diagram toward different morphologies. The PISA system was based on hydrophilic poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC), which was chain extended with hydrophobic methyl methacrylate (MMA) in various concentrations of curcumin. According to transmission electron microscopy, the presence of curcumin led to the transition of, for example, worms to polymersome and micelles to worms analysis. To understand the interaction between polymer particles and drug, small-angle X-ray scattering (SAXS), small-angle neutron scattering (SANS), and fluorescence lifetime measurements were carried out. These measurements show that curcumin is predominantly located in the core in the case of micelles and worms while it is found in the shell of polymersomes. The change in morphology influences the cellular uptake by MCF-7 cells and the movement of the particles in multicellular cancer spheroids (3D model). With the increasing amount of drug, the cellular uptake of micelles and worms was enhanced with the increasing grafting density of MPC chains, which contrasts the decreasing cellular uptake in the higher drug-loaded polymersomes due to the lower shell hydration.

  • 35.
    Cao, Cheng
    et al.
    Centre for Advanced Macromolecular Design, School of Chemistry, The University of New South Wales, Sydney, 2052, Australia.
    Zhang, Lin
    Centre for Advanced Macromolecular Design, School of Chemistry, The University of New South Wales, Sydney, 2052, Australia.
    Kent, Ben
    Centre for Advanced Macromolecular Design, School of Chemistry, The University of New South Wales, Sydney, 2052, Australia.
    Wong, Sandy
    Centre for Advanced Macromolecular Design, School of Chemistry, The University of New South Wales, Sydney, 2052, Australia.
    Garvey, Christopher J.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Australian Centre for Neutron Scattering, Australia Nuclear Science and Technology Organisation, Lucas Heights, 2234, Australia; Lund Institute for Advanced Neutron and X-ray Science, Lund, 22100, Sweden.
    Stenzel, Martina H.
    Centre for Advanced Macromolecular Design, School of Chemistry, The University of New South Wales, Sydney, 2052, Australia.
    The Protein Corona Leads to Deformation of Spherical Micelles2021In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 60, no 18, p. 10342-10349Article in journal (Refereed)
    Abstract [en]

    The formation of a non-specific protein corona around nanoparticles (NPs) has been identified as one of the culprits for failed nanomedicine. The amount and type of adsorbed protein from the blood plasma are known to determine the fate of NPs and the accessibility of targeting ligands. Herein, we show that the adsorbed protein may not only enlarge the NPs and change their surface properties but also, in the case of soft NPs such as polymer micelles, lead to deformation. Poly(1-O-methacryloyl -beta-D-fructopyranose)-b-poly(methylmethacrylate) (P(1-O-MAFru)-b-PMMA) block co-polymers were self-assembled into NPs with a spherical core-shell morphology as determined by small angle neutron scattering (SANS). Upon incubation with albumin, TEM, SANS, and small angle X-ray scattering (SAXS) revealed the adsorption of albumin and deformation of the NPs with a spheroid geometry. Removal of the protein led to the reversal of the morphology back to the spherical core-shell structure. Structural studies and cell studies of uptake of the NPs imply that the observed deformation may influence blood circulation time and cell uptake.

  • 36.
    Chushkin, Yuriy
    et al.
    ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France.
    Gulotta, Alessandro
    Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden.
    Roosen-Runge, Felix
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden.
    Pal, Antara
    Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden.
    Stradner, Anna
    Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden; Lund Institute of advanced Neutron and X-ray Science LINXS, Lund University, Lund, Sweden.
    Schurtenberger, Peter
    Division of Physical Chemistry, Lund University, Naturvetarvägen 14, 22100 Lund, Sweden; Lund Institute of advanced Neutron and X-ray Science LINXS, Lund University, Lund, Sweden.
    Probing Cage Relaxation in Concentrated Protein Solutions by X-Ray Photon Correlation Spectroscopy2022In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 129, no 23, article id 238001Article in journal (Refereed)
    Abstract [en]

    Diffusion of proteins on length scales of their size is crucial for understanding the machinery of living cells. X-ray photon correlation spectroscopy (XPCS) is currently the only way to access long-time collective diffusion on these length scales, but radiation damage so far limits the use in biological systems. We apply a new approach to use XPCS to measure cage relaxation in crowded α-crystallin solutions. This allows us to correct for radiation effects, obtain missing information on long time diffusion, and support the fundamental analogy between protein and colloid dynamical arrest.

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  • 37. Clifton, Luke A
    et al.
    Campbell, Richard A
    Sebastiani, Federica
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Campos-Terán, José
    Gonzalez-Martinez, Juan F
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Björklund, Sebastian
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Sotres, Javier
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Cárdenas, Marité
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Design and use of model membranes to study biomolecular interactions using complementary surface-sensitive techniques.2020In: Advances in Colloid and Interface Science, ISSN 0001-8686, E-ISSN 1873-3727, Vol. 277, article id 102118Article in journal (Refereed)
    Abstract [en]

    Cellular membranes are complex structures and simplified analogues in the form of model membranes or biomembranes are used as platforms to understand fundamental properties of the membrane itself as well as interactions with various biomolecules such as drugs, peptides and proteins. Model membranes at the air-liquid and solid-liquid interfaces can be studied using a range of complementary surface-sensitive techniques to give a detailed picture of both the structure and physicochemical properties of the membrane and its resulting interactions. In this review, we will present the main planar model membranes used in the field to date with a focus on monolayers at the air-liquid interface, supported lipid bilayers at the solid-liquid interface and advanced membrane models such as tethered and floating membranes. We will then briefly present the principles as well as the main type of information on molecular interactions at model membranes accessible using a Langmuir trough, quartz crystal microbalance with dissipation monitoring, ellipsometry, atomic force microscopy, Brewster angle microscopy, Infrared spectroscopy, and neutron and X-ray reflectometry. A consistent example for following biomolecular interactions at model membranes is used across many of the techniques in terms of the well-studied antimicrobial peptide Melittin. The overall objective is to establish an understanding of the information accessible from each technique, their respective advantages and limitations, and their complementarity.

  • 38. Coman, Vasile
    et al.
    Vaz-Dominguez, Cristina
    Ludwig, Roland
    Harreither, Wolfgang
    Haltrich, Dietmar
    De Lacey, Antonio L.
    Ruzgas, Tautgirdas
    Malmö högskola, Faculty of Health and Society (HS).
    Gorton, Lo
    Shleev, Sergey
    Malmö högskola, Faculty of Health and Society (HS).
    A membrane-, mediator-, cofactor-less glucose/oxygen biofuel cell2008In: Physical Chemistry Chemical Physics, Vol. 10, no 40, p. 6093-6096Article in journal (Refereed)
  • 39.
    Conn, Charlotte E
    et al.
    RMIT University, Australia.
    de Campo, Liliana
    Australian Nuclear Science and Technology Organisation.
    Whitten, Andrew E
    Australian Nuclear Science and Technology Organisation.
    Garvey, Christopher J.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Australian Nuclear Science and Technology Organisation; Lund Institute for Advanced Neutron and X-Ray Science.
    Krause-Heuer, Anwen M
    Australian Nuclear Science and Technology Organisation.
    van 't Hag, Leonie
    Monash University, Monash University.
    Membrane Protein Structures in Lipid Bilayers; Small-Angle Neutron Scattering With Contrast-Matched Bicontinuous Cubic Phases2020In: Frontiers in chemistry, ISSN 2296-2646, Vol. 8, article id 619470Article in journal (Refereed)
    Abstract [en]

    . Deuterated vesicles can be used to obtain the radius of gyration of membrane proteins, but protein-protein interference effects within the vesicles severely limits this method such that the protein structure cannot be modeled. We show herein that different membrane protein conformations can be distinguished within the lipid bilayer of the bicontinuous cubic phase using contrast-matching. Time-resolved studies performed using SANS illustrate the complex phase behavior in lyotropic liquid crystalline systems and emphasize the importance of this development. We believe that studying membrane protein structures and phase behavior in contrast-matched lipid bilayers will advance both biological and pharmaceutical applications of membrane-associated proteins, biosensors and food science.

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  • 40.
    Cárdenas, Marité
    et al.
    Malmö högskola, Faculty of Health and Society (HS).
    Arnebrant, Thomas
    Malmö högskola, Faculty of Health and Society (HS).
    Schillén, Karin
    Alfredsson, Viveka
    Duan, Rui-DOng
    Nyberg, Lena
    Solubilization of sphingomyelin vesicles by addition of a bile salt2008In: Chemistry and Physics of Lipids, ISSN 0009-3084, E-ISSN 1873-2941, Vol. 151, no 1, p. 10-17Article in journal (Refereed)
    Abstract [en]

    The interactions of the bile salt sodium taurocholate (TC) in 50 mM Trizma–HCl buffer and 150 mM NaCl (pH 9) at 37 °C with membranes composed of sphingomyelin (SM) were studied by dynamic light scattering, cryogenic transmission electron microscopy (cryo-TEM) and turbidity measurements. Small unilamellar SM vesicles were prepared by extrusion. Below the CMC of TC, taurocholate addition leads to vesicle growth due to incorporation of the taurocholate molecules into the vesicle bilayer. At around half the CMC of the bile salt, the SM vesicles are transformed into SM/TC mixed worm-like micelles, which are visualized by cryo-TEM for the first time. Further increase in the taurocholate concentration leads to the rupture of these structures into small spherical micelles. Interestingly, large non-spherical micelles were also identified for pure taurocholate solutions. Similar threadlike structures have been reported earlier for the bile salt sodium taurodeoxycholate [Rich, A., Blow, D., 1958. Nature 182, 1777; Blow, D.M., Rich, A., 1960. J. Am. Chem. Soc. 82, 3566–3571; Galantini, L., Giglio, E., La Mesa, C., Viorel-Pavel, N., Punzo, F., 2002. Langmuir 18, 2812] and for mixtures of taurocholate and phosphatidylcholate [Ulmius, J., Lindblom, G., Wennerström, H., Johansson, L.B.-Å., Fontel, K., Söderman, O., Ardvisson, G., 1982. Biochemistry 21, 1553; Hjelm, R.P., Thiyagarajan, P., Alkan-Onyuksel, H., 1992. J. Phys. Chem. 96, 8653] as determined by various scattering methods.

  • 41.
    Cárdenas, Marité
    et al.
    Malmö högskola, Faculty of Health and Society (HS).
    Arnebrant, Thomas
    Malmö högskola, Faculty of Health and Society (HS).
    Thomas, Robert
    Fragnetto, Giovanna
    Rennie, Adrian
    Lindh, Liselott
    Malmö högskola, Faculty of Odontology (OD).
    Human Saliva Forms a Complex Film Structure on Alumina Surfaces2007In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 8, no 1, p. 65-69Article in journal (Refereed)
    Abstract [en]

    Films formed from saliva on surfaces are important for maintenance of oral health and integrity by protection against chemical and/or biological agents. The aim of the present study was to investigate adsorbed amounts, thickness and the structure of films formed from human whole saliva on alumina surfaces by means of in situ ellipsometry, neutron reflectivity and atomic force microscopy. Alumina (Al2O3, synthetic sapphire) is a relevant and interesting substrate for saliva adsorption studies as it has an isoelectric point close to that of tooth enamel. The results showed that saliva adsorbs rapidly on alumina. The film could be modelled in two layers: an inner and dense thin region which forms a uniform layer, and an outer, more diffuse and thicker region that protrudes towards the bulk of the solution. The film morphology described a uniformly covering dense layer and a second outer layer containing polydisperse adsorbed macromolecules or aggregates.

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  • 42.
    Cárdenas, Marité
    et al.
    Malmö högskola, Faculty of Health and Society (HS). Malmö högskola, Faculty of Odontology (OD).
    Elofsson, Ulla
    Lindh, Liselott
    Malmö högskola, Faculty of Health and Society (HS). Malmö högskola, Faculty of Odontology (OD).
    Salivary mucin MUC5B could be an important component of in vitro pellicles of human saliva: an in situ ellipsometry and atomic force microscopy study2007In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 8, no 4, p. 1149-1156Article in journal (Refereed)
    Abstract [en]

    This paper describes a combined investigation of the salivary and MUC5B films structure and topography in conditions similar to those found in the oral cavity in terms of ionic strength, pH, and protein concentration. AFM and ellipsometry were successfully used to give a detailed picture of the film structure and topography both on hydrophilic and on hydrophobic substrata. Regardless of the substrata, the salivary film can be described as having a two sublayer structure in which an inner dense layer is decorated by large aggregates. However, the shape and height of these larger aggregates largely depend on the type of substrata used. Additionally, we show that the adsorption of MUC5B is controlled by the type of substrata and the MUC5B film topography is similar to that of the larger aggregates present in the salivary films, especially on hydrophobic substrates. Therefore, we conclude that MUC5B is a major component in the salivary film when formed on hydrophobic substrates. Furthermore, we studied how resistant the salivary and MUC5B films are against elutability by buffer rinsing and addition of SDS solution. We conclude that the adsorbed proteins contain fractions with varying binding strengths to the two types of surfaces. Specifically, we have shown that the large MUC5B biomacromolecules on the hydrophobic substrates are especially resistant to both elution with buffer solution and SDS. Therefore, these large mucins can be responsible for the increased resistance of HWS films on hydrophobic substrates and can protect the intraoral surfaces against surface-active components present in oral health care products.

  • 43. Dagys, Marius
    et al.
    Haberska, Karolina
    Shleev, Sergey
    Malmö högskola, Faculty of Health and Society (HS).
    Arnebrant, Thomas
    Malmö högskola, Faculty of Health and Society (HS).
    Kulys, Juozas
    Ruzgas, Tautgirdas
    Malmö högskola, Faculty of Health and Society (HS).
    Laccase-gold nanoparticle assisted bioelectrocatalytic reduction of oxygen2010In: Electrochemistry communications, ISSN 1388-2481, E-ISSN 1873-1902, Vol. 12, no 7, p. 933-935Article in journal (Refereed)
    Abstract [en]

    It was found that homogeneous activity of Trametes hirsuta laccase is considerably diminished in the presence of gold nanoparticles (Au-NPs). Heterogeneous electron transfer studies revealed that Au-NPs facilitate direct electron transfer (DET) between the T1 copper site of the laccase and the surface of Au-NP modified electrodes. DET was characterized by the standard heterogeneous ET constant of 0.5 +/- 0.6 s(-1) at Au-NPs with an average diameter of 50 nm. As a consequence of this a well pronounced DET based bioelectrocatalytic oxygen reduction with current densities of 5-30 mu A cm(-2) has been achieved at the laccase-Au-NP modified electrodes.

  • 44.
    Darmal, Khalid
    Malmö University, Faculty of Education and Society (LS), Department of Natural Science, Mathematics and Society (NMS).
    Kemiundervisning ur ett relevant perspektiv i högstadiet2022Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med uppsatsen är att undersöka kemilärares uppfattning om vad som är en relevant kemiundervisning samt hur de arbetar för att göra kemiämnet relevant för sina elever på högstadiet. Studien är baserad på en kvalitativ metod med semistrukturerade intervjuer. I studien används Stuckeys et. al (2013) modell som handlar om relevansen av naturvetenskaplig utbildning och Roberts vision Ⅰ och vision Ⅱ för Scientific Literacy som ett teoretiskt ramverk. Empirin i denna studie har analyserats framför allt på ett deduktivt sätt men det finns även en del empiri som har präglats av en induktiv strategi. Resultaten av empirin visar att lärarna tolkar begreppet relevans på olika sätt och relaterar detta begrepp till olika sammanhang. 

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  • 45.
    Ding, R.
    et al.
    Nanyang Technological University, Singapore.
    Joon, N. K.
    Åbo Akademi University, Finland.
    Ahamed, A.
    Åbo Akademi University, Finland; Nanyang Environment and Water Research Institute, Singapore.
    Shafaat, Atefeh
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Guzinski, M.
    Vanderbilt University Medical Center, Nashville, USA.
    Wagner, M.
    Nanyang Environment and Water Research Institute, Singapore.
    Ruzgas, Tautgirdas
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Bobacka, J.
    Åbo Akademi University, Finland.
    Lisak, G.
    Nanyang Technological University, Singapore; Nanyang Environment and Water Research Institute, Singapore.
    Gold-modified paper as microfluidic substrates with reduced biofouling in potentiometric ion sensing2021In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 344, article id 130200Article in journal (Refereed)
    Abstract [en]

    Microfluidic sampling media based on paper and its modifications with either gold nanoparticles or sputtered gold were evaluated for potentiometric determination of Na+, K+, and Cl– ions in clinically relevant samples. The measurements were conducted in comparison to other commonly considered microfluidic substrates, i.e. sponge, polyester textile, and polyamide textile. Ion determination was done by using solid-contact ion-selective electrodes based on plasticized PVC membranes for Na+, K+, and Cl– ions and utilizing PEDOT(PSS) or PEDOT(Cl) as the ion-to-electron transducer. The solid-contact ion-selective electrodes and a solid-state reference electrode were placed directly on the substrate into which the sample solution was wicked. Transport of bovine serum albumin (BSA) through the paper substrate was studied by ellipsometry. Modification of the paper substrates by gold nanoparticles (AuNPs) was found to slow down the transport of BSA through the paper, when compared with unmodified paper substrates and when compared with all the other alternative sampling matrices studied. The retention of BSA obtained with AuNP-modified paper substrates significantly improved the accuracy of the potentiometric ion determinations in sweat, saliva, artificial tears, and artificial serum. The potentiometric results were validated by inductively coupled plasma optical emission spectrometry (ICP-OES) and ion chromatography (IC). The study indicates that modification of paper by AuNPs is a feasible approach to reduce biofouling of sensors that are used in the paper-based analysis of clinically relevant samples. © 2021 Elsevier B.V.

  • 46.
    El-Schich, Zahra
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Zhang, Yuecheng
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Göransson, Tommy
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Dizeyi, Nishtman
    Lund University.
    Persson, Jenny L.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Umeå University.
    Johansson, Emil
    Umeå University.
    Caraballo, Remi
    Umeå University.
    Elofsson, Mikael
    Umeå University.
    Shinde, Sudhirkumar
    World Peace University, India.
    Sellergren, Börje
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Gjörloff Wingren, Anette
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Sialic Acid as a Biomarker Studied in Breast Cancer Cell Lines In Vitro Using Fluorescent Molecularly Imprinted Polymers2021In: Applied Sciences, E-ISSN 2076-3417, Vol. 11, no 7, article id 3256Article in journal (Refereed)
    Abstract [en]

    Sialylations are post-translational modifications of proteins and lipids that play important roles in many cellular events, including cell-cell interactions, proliferation, and migration. Tumor cells express high levels of sialic acid (SA), which are often associated with the increased invasive potential in clinical tumors, correlating with poor prognosis. To overcome the lack of natural SA-receptors, such as antibodies and lectins with high enough specificity and sensitivity, we have used molecularly imprinted polymers (MIPs), or "plastic antibodies", as nanoprobes. Because high expression of epithelial cell adhesion molecule (EpCAM) in primary tumors is often associated with proliferation and a more aggressive phenotype, the expression of EpCAM and CD44 was initially analyzed. The SA-MIPs were used for the detection of SA on the cell surface of breast cancer cells. Lectins that specifically bind to the a-2,3 SA and a-2,6 SA variants were used for analysis of SA expression, with both flow cytometry and confocal microscopy. Here we show a correlation of EpCAM and SA expression when using the SA-MIPs for detection of SA. We also demonstrate the binding pattern of the SA-MIPs on the breast cancer cell lines using confocal microscopy. Pre-incubation of the SA-MIPs with SA-derivatives as inhibitors could reduce the binding of the SA-MIPs to the tumor cells, indicating the specificity of the SA-MIPs. In conclusion, the SA-MIPs may be a new powerful tool in the diagnostic analysis of breast cancer cells.

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  • 47.
    Engstedt, Jenni
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces. Camurus AB, Ideon Science Park, Gamma Building, Sölvegatan 41, SE-22379 Lund, Sweden.
    Barauskas, Justas
    Camurus AB, Ideon Science Park, Gamma Building, Sölvegatan 41, SE-22379 Lund, Sweden.
    Kocherbitov, Vitaly
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Phase behavior of soybean phosphatidylcholine and glycerol dioleate in hydrated and dehydrated states studied by small-angle X-ray scattering2023In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 19, no 43, p. 8305-8317Article in journal (Refereed)
    Abstract [en]

    Soybean phosphatidylcholine (SPC) and glycerol dioleate (GDO) form liquid crystal nanostructures in aqueous environments, and their mixtures can effectively encapsulate active pharmaceutical ingredients (API). When used in a subcutaneous environment, the liquid crystalline matrix gradually hydrates and degrades in the tissue whilst slowly releasing the API. Hydration dependent SPC/GDO phase behavior is complex, non-trivial, and still not fully understood. A deeper understanding of this system is important for controlling its function in drug delivery applications. The phase behavior of the mixture of SPC/GDO/water was studied as a function of hydration and lipid ratio. Small-angle X-ray scattering (SAXS) was used to identify space groups in liquid crystalline phases and to get detailed structural information on the isotropic reverse micellar phase. The reported pseudo ternary phase diagram includes eight different phases and numerous multiphase regions in a thermodynamically consistent way. For mixtures with SPC as the predominant component, the system presents a reverse hexagonal, lamellar and R3m phase. For mixtures with lower SPC concentrations, reverse cubic (Fd3m and Pm3n) as well as intermediate and isotropic micellar phases were identified. By modeling the SAXS data using a core–shell approach, the properties of the isotropic micellar phase were studied in detail as a function of concentration. Moreover, SAXS analysis of other phases revealed new structural features in relation to lipid–water interactions. The new improved ternary phase diagram offers valuable insight into the complex phase behavior of the SPC/GDO system. The detailed structural information is important for understanding what APIs can be incorporated in the liquid crystal structure.

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  • 48.
    Esmail Tehrani, Sheida
    et al.
    Tech Univ Denmark, Natl Ctr Nano Fabricat & Characterizat, DTU Nanolab, Orsteds Plads,Bldg 347, DK-2800 Lyngby, Denmark..
    Quang Nguyen, Long
    Tech Univ Denmark, Natl Ctr Nano Fabricat & Characterizat, DTU Nanolab, Orsteds Plads,Bldg 347, DK-2800 Lyngby, Denmark..
    Garelli, Giulia
    Tech Univ Denmark, Natl Ctr Nano Fabricat & Characterizat, DTU Nanolab, Orsteds Plads,Bldg 347, DK-2800 Lyngby, Denmark..
    Jensen, Bettina M.
    Copenhagen Univ Hosp Herlev Gentofte, Allergy Clin, Gentofte Hosp Vej 8, DK-2900 Hellerup, Denmark..
    Ruzgas, Tautgirdas
    Malmö University, Biofilms Research Center for Biointerfaces. Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV).
    Emneus, Jenny
    Tech Univ Denmark, Dept Biotechnol & Biomed DTU Bioengn, Bldg 423, DK-2800 Lyngby, Denmark..
    Sylvest Keller, Stephan
    Tech Univ Denmark, Natl Ctr Nano Fabricat & Characterizat, DTU Nanolab, Orsteds Plads,Bldg 347, DK-2800 Lyngby, Denmark..
    Hydrogen Peroxide Detection Using Prussian Blue-modified 3D Pyrolytic Carbon Microelectrodes2021In: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 33, no 12, p. 2516-2528Article in journal (Refereed)
    Abstract [en]

    A highly sensitive amperometric Prussian blue-based hydrogen peroxide sensor was developed using 3D pyrolytic carbon microelectrodes. A 3D printed multielectrode electrochemical cell enabled simultaneous highly reproducible Prussian blue modification on multiple carbon electrodes. The effect of oxygen plasma pre-treatment and deposition time on Prussian blue electrodeposition was studied. The amperometric response of 2D and 3D sensors to the addition of hydrogen peroxide in mu M and sub-mu M concentrations in phosphate buffer was investigated. A high sensitivity comparable to flow injection systems and a detection limit of 0.16 mu M was demonstrated with 3D pyrolytic carbon microelectrodes at stirred batch condition

  • 49.
    Fagerström, Anton
    et al.
    Malmö högskola, Faculty of Health and Society (HS).
    Kocherbitov, Vitaly
    Malmö högskola, Faculty of Health and Society (HS).
    Lamberg, Peter
    Malmö högskola, Faculty of Health and Society (HS).
    Bergström, Karin
    Westbye, Peter
    Ruzgas, Tautgirdas
    Malmö högskola, Faculty of Health and Society (HS).
    Engblom, Johan
    Malmö högskola, Faculty of Health and Society (HS).
    Factors Affecting Transport of Tebuconazole over Silicone Membrane and Leaf Cuticle2010In: Proceedings of the 9th International Symposium on Adjuvants for Agrochemicals, ISAA Society , 2010, p. 329-336Conference paper (Other academic)
  • 50.
    Falk, Magnus
    et al.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Nilsson, Emelie J.
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Cirovic, Stefan
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Tudosoiu, Bogdan
    Covercast AB, Drottensgatan 4, 222 23 Lund, Sweden.
    Shleev, Sergey
    Malmö University, Faculty of Health and Society (HS), Department of Biomedical Science (BMV). Malmö University, Biofilms Research Center for Biointerfaces.
    Wearable Electronic Tongue for Non-Invasive Assessment of Human Sweat2021In: Sensors, E-ISSN 1424-8220, Vol. 21, no 21, article id 7311Article in journal (Refereed)
    Abstract [en]

    Sweat is a promising biofluid in allowing for non-invasive sampling. Here, we investigate the use of a voltammetric electronic tongue, combining different metal electrodes, for the purpose of non-invasive sample assessment, specifically focusing on sweat. A wearable electronic tongue is presented by incorporating metal electrodes on a flexible circuit board and used to non-invasively monitor sweat on the body. The data obtained from the measurements were treated by multivariate data processing. Using principal component analysis to analyze the data collected by the wearable electronic tongue enabled differentiation of sweat samples of different chemical composition, and when combined with 1H-NMR sample differentiation could be attributed to changing analyte concentrations.

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