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  • 701. Wang, Richard B.
    et al.
    Koerbel, Sabine
    Saha, Santanu
    Botti, Silvana
    Skorodumova, Natalia V.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Multiscale Materials Modelling. Uppsala University, Sweden.
    Structure and Optical Properties of Small (TiO2)(n) Nanoparticles, n=21-242017In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 121, no 17, p. 9528-9536Article in journal (Refereed)
    Abstract [en]

    Recently, nanostructured TiO2 ("black TiO2") has been discovered to absorb visible light, which makes, it an efficient material for water splitting. Hydrogenization has been proposed to be at the origin of this beneficial electronic structure of black TiO2. Here, we investigate, using ab initio methods, alternative mechanisms related to structure modifications in nanoclusters that could be responsible for absorption in the visible range. To that end, we apply a combination of computational structure prediction using simulated annealing and minima-hopping methods based on density-functional theory to predict low-energy configurations and time-dependent density-functional theory (TDDFT) using a hybrid functional with optimized Hartree Fock content to obtain optical absorption edges.

  • 702. Wang, X.
    et al.
    Herting, G.
    Odnevall Wallinder, I.
    Blomberg, Eva
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. Department of Chemistry, Surface and Corrosion Science, KTH Royal Institute of Technology.
    Adsorption of bovine serum albumin on silver surfaces enhances the release of silver at pH neutral conditions2015In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 28, p. 18524-18534Article in journal (Refereed)
    Abstract [en]

    Metallic biomaterials are widely used to replace and/or restore the function of damaged bodily parts. The use of silver as antibacterial coatings onto implants has recently gained large interest in medical applications. The extent of silver that can be released into different biological fluids from such coatings is, except for the surface characteristics of the coating, governed by parameters such as protein characteristics, adsorbed layer properties, formation of silver-protein complexes as well as concentrations of proteins in the solution. This study aims to relate the structure of adsorbed net negatively charged bovine serum albumin (BSA), which is the most abundant protein in serum, to the release of silver from metallic silver surfaces in order to elucidate if the net charge of the protein has any effect of the silver release. Simultaneous adsorption measurements were performed in real time on the very same surface using combined ellipsometry and quartz crystal microbalance with dissipation monitoring (QCM-D) measurements to provide a more comprehensive understanding on adsorption kinetics and layer structures. The amount of released silver into solution was measured by means of graphite furnace atomic absorption spectroscopy (GF-AAS). The structure of the adsorbed BSA layer largely influenced the amount of released silver, an enhancement that increased with BSA concentration. These observations are in complete contrast to the effect of net positively charged lysozyme (LSZ) adsorbed on silver, previously studied by the authors, for which a complete surface coverage suppressed the possibility for silver release. The underlying mechanisms behind the enhanced release of silver in the presence of BSA were mainly attributed to surface complexation between BSA and silver followed by an enhanced exchange rate of these surface complexes with BSA molecules in the solution, which in turn increase the amount of released silver in solution.

  • 703.
    Wang, Xiaojing
    et al.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Bleiker, Simon J.
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Antelius, Mikael
    Stemme, Göran
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering (EES), Micro and Nanosystems.
    Narrow footprint copper sealing rings for low-temperature hermetic wafer-level packaging2017In: TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems, Institute of Electrical and Electronics Engineers (IEEE), 2017, p. 423-426, article id 7994077Conference paper (Refereed)
    Abstract [en]

    This paper reports a narrow footprint sealing ring design for low-temperature, hermetic, and mechanically stable wafer-level packaging. Copper (Cu) sealing rings that are as narrow as 8 μm successfully seal the enclosed cavities on the wafers after bonding at a temperature of 250 °C. Different sealing structure designs are evaluated and demonstrate excellent hermeticity after 3 months of storage in ambient atmosphere. A leak rate of better than 3.6×10'16 mbarL/s is deduced based on results from residual gas analysis measurements. The sealing yield after wafer bonding is found to be not limited by the Cu sealing ring width but by a maximum acceptable wafer-to-wafer misalignment.

  • 704.
    Wang, Yan
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Bergenstråhle-Wohlert, Malin
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Tu, Yaoquan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wohlert, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Swelling and dimensional stability of xyloglucan/montmorillonite nanocomposites in moist conditions from molecular dynamics simulations2017In: Computational Materials Science, ISSN 0927-0256, Vol. 128, p. 191-197Article in journal (Refereed)
    Abstract [en]

    Nacre-mimetic biocomposites made from the combination of montmorillonite clay and the hemicellulose xyloglucan give materials that retain much of their material properties even at high relative humidity. Here, a model composite system consisting of two clay platelets intercalated by xyloglucan oligomers was studied at different levels of hydration using molecular dynamics simulations, and compared to the pure clay. It was found that xyloglucan inhibits swelling of the clay at low water contents by promoting the formation of nano-sized voids that fill with water without affecting the material's dimensions. At higher water contents the XG itself swells, but at the same time maintaining contact with both platelets across the gallery, thereby acting as a physical cross-linker in a manner similar to the role of XG in the plant cell wall.

  • 705.
    Wang, Yan
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Wohlert, Jakob
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Tu, Yaoquan
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Molecular dynamics simulation of strong interaction mechanisms at wet interfaces in clay-polysaccharide nanocomposites2014In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, no 25, p. 9541-9547Article in journal (Refereed)
    Abstract [en]

    Bio-composites comprised of the polysaccharide xyloglucan (XG) and montmorillonite (MTM) clay has potential as a 'green' replacement of conventional petroleum-derived polymers in the packaging industry. These materials have been shown to possess excellent material properties, even in high relative humidity. Although interfacial interaction between XG and MTM, and the molecular structure of XG can be identified as key parameters for the complex formation process and the resulting tensile properties, these properties are usually difficult to address using experimental methods. Here we use molecular dynamics (MD) simulations to study the adsorption of fully atomistic models of both native and chemically modified XG to MTM clay surfaces in explicit water. We show that the driving force for adsorption is a favorable change in enthalpy, and furthermore that native XG adsorbs stronger than modified XG. This highlights the importance of molecular structure details to molecular adhesion. The present study provides insights into the molecular scale adsorption mechanisms and can therefore help in designing routes for further improvements of bio-composite materials.

  • 706.
    Wang, Ying
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Rinkevicius, Zilvinas
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ahlquist, Mårten S. G.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Formation of N-oxide in the third oxidation of [Ru-II(tpy)(L)(OH2)](2+)2017In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 53, no 41, p. 5622-5624Article in journal (Refereed)
    Abstract [en]

    The widely studied water oxidation catalyst [Ru-II(tpy)(L)(OH2)](2+) (tpy = 2,2': 6',2"-terpyridine, L = bpy = 2,2'-bipyridine or L = bpm = 2,2'-bipyrimidine) is still under scrutiny. Here we present a new suggestion for one of the key steps, results that could resolve conflicting interpretations of experimental results. Instead of the previously proposed Ru-V=O species, a proposed key species in water oxidation catalysis, we propose that the third oxidation of RuII could lead to a Ru-III N-oxide, via rapid water coordination followed by oxidation and concerted N-O bond formation.

  • 707.
    Warczak, Magdalena
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gryszel, Maciej
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Jakesova, Marie
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Derek, Vedran
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering. Rudjer Boskovic Inst, Croatia.
    Glowacki, Eric
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Organic semiconductor perylenetetracarboxylic diimide (PTCDI) electrodes for electrocatalytic reduction of oxygen to hydrogen peroxide2018In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, no 16, p. 1960-1963Article in journal (Refereed)
    Abstract [en]

    Hydrogen peroxide is one of the most important industrial chemicals and there is great demand for the production of H2O2 usingmore sustainable and environmentally benign methods. We show electrochemical production of H2O2 by the reduction of O-2, enabled by an organic semiconductor catalyst, N,N-dimethyl perylenetetracarboxylic diimide (PTCDI). We make PTCDI cathodes that are capable of stable and reusable operation in aqueous electrolytes in a pH range of 1-13 with a catalytic figure of merit as high as 26 kg H2O2 per g catalyst per h. These performance and stability open new avenues for organic small molecule semiconductors as electrocatalysts.

  • 708.
    Webling, Kristin
    Stockholm University, Faculty of Science, Department of Neurochemistry.
    Galanin receptor ligands: Design, synthesis, characterization and biological effects2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Galanin is a 29/30 amino acid long bioactive peptide discovered over 30 years ago when C-terminally amidated peptides were isolated from porcine intestines. The name galanin originates from a combination of the first and last amino acids - G from glycine and the rest from alanine. The first 15 amino acids are highly conserved among species which indicates that the N-terminus is important for receptor recognition and subsequent binding. Galanin exerts its effects by binding to three different G-protein coupled receptors, which all differ in regional distribution, the affinity for shortened galanin fragments, as well as the G-protein signaling cascade used. At the time of publication, galanin was found to cause muscle contraction as well as hyperglycemia.  Over the years, galanin has been reported to be involved in a wide variety of biological and pathological functions, for example epilepsy, food intake and depression.

    Determining the specific involvement of the three different galanin receptors in several biological and pathological processes is limited by the small amount of galanin receptor selective/specific ligands available as research tools. Furthermore, the fast degradation of peptides limits the administration routes in animal studies.

    This thesis aims at developing new galanin receptor-selective ligands to help delineate the involvement of the three different galanin receptors also known as the galaninergic system.

    Paper 1 demonstrates that the neuroprotective effects of galanin in a kainic acid induced excitotoxic animal model was mediated through galanin receptor 1. Furthermore, a new robust protocol for evaluating G-protein signaling using a label-free real time impedance technique was presented and compared to two different classical second-messenger assays.

    Paper 2 presents a series of systemically active galanin receptor 2 selective ligands subsequently evaluated in two different depression-like animal models.

    In conclusion, this thesis presents six new galanin ligands, which can be used to evaluate the galaninergic system as well as to investigate the possible use of peptides as pharmaceuticals.

  • 709.
    Wedin, Helena
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Antonsson, Stefan
    Ragnar, Martin
    Lindström, Mikael E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Influence Of Xylan Content On The Oxygen Delignification Performance Of Eucalypt Kraft Pulps As Studied Using Prehydrolysis And Xylanase Treatments2012In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 7, no 4, p. 5527-5541Article in journal (Refereed)
    Abstract [en]

    Common metrics for evaluating the efficiency of oxygen delignification include the kappa number and Klason lignin content. As a change in xylan content often leads to a change in HexA content, the kappa number must be corrected for the HexA contribution before evaluating the degree of oxygen delignification when trying to understand the process in detail. Questions could also be raised about the accuracy of the Klason lignin method for oxygen-delignified hardwood kraft pulps, since the amount of residual lignin is small in such pulp. This study investigates the influence of xylan content on oxygen delignification efficiency in Eucalyptus urograndis kraft pulps. Xylan content was varied using two methods: treatment with xylanase and with acid prehydrolysis for various times before kraft cooking. The degree of oxygen delignification, expressed as the HexA-corrected kappa number, indicated no significant trend with xylan removal, and no significant trend was evident when expressed as Klason lignin content.

  • 710.
    Wedin, Helena
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Fiskari, Juha
    Kovasin, Kari
    Ragnar, Martin
    Lindström, Mikael E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Further insights into extended-impregnation kraft cooking of birch2012In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, no 5, p. 890-899Article in journal (Refereed)
    Abstract [en]

    Extended-impregnation kraft cooking (EIC) is a cooking concept that combines prolonged impregnation with modern improved modified kraft cooking. In the current investigation, the EIC cooking of birch was studied in relation to conventional kraft cooking. Specifically, the reject content and carbohydrate yield retention when terminating at a high cooking kappa number were examined. It was demonstrated that EIC cooking reduced the reject content. Unexpectedly, a high cooking kappa number led to no increase in carbohydrate yield, possibly due to the chemical composition of birch wood and the EIC cook lab procedure. A large amount of liquor was withdrawn after the impregnation, resulting in a loss of dissolved xylan that otherwise could have redeposited on the fibres and contributed to the carbohydrate yield. The effects of EIC cooking on extended oxygen delignification, bleaching chemical requirement in a D(OP)DP sequence, and strength properties were also examined. Compared with conventional lab cooking, EIC cooking resulted in a lower bleaching chemical requirement and similar strength properties.

  • 711.
    Wedin, Helena
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Sevastyanova, Olena
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Evtuguin, Dmitry
    Ragnar, Martin
    Lindström, Mikael E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.
    Influence of extended-impregnation kraft cooking on the xylan structure of Eucalyptus urograndisManuscript (preprint) (Other academic)
  • 712.
    Wehbe, Mohamed
    et al.
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada.;Univ British Columbia, Fac Pharmaceut Sci, Vancouver, BC, Canada..
    Anantha, Malathi
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada..
    Backstrom, Ian
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada..
    Leung, Ada
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada.;Univ British Columbia, Dept Pathol & Lab Med, Vancouver, BC V5Z 1M9, Canada..
    Chen, Kent
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada..
    Malhotra, Armaan
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada..
    Edwards, Katarina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry. Uppsala Univ, Dept Chem, 3 Husargatan B7, Uppsala, Sweden..
    Bally, Marcel B.
    British Columbia Canc Res Ctr, Expt Therapeut, Vancouver, BC V5Z 1L3, Canada.;Univ British Columbia, Fac Pharmaceut Sci, Vancouver, BC, Canada.;Univ British Columbia, Dept Pathol & Lab Med, Vancouver, BC V5Z 1M9, Canada.;Ctr Drug Res & Dev, Vancouver, BC, Canada..
    Nanoscale Reaction Vessels Designed for Synthesis of Copper-Drug Complexes Suitable for Preclinical Development2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 4, article id e0153416Article in journal (Refereed)
    Abstract [en]

    The development of copper-drug complexes (CDCs) is hindered due to their very poor aqueous solubility. Diethyldithiocarbamate (DDC) is the primary metabolite of disulfiram, an approved drug for alcoholism that is being repurposed for cancer. The anticancer activity of DDC is dependent on complexation with copper to form copper bis-diethyldithiocarbamate (Cu(DDC)(2)), a highly insoluble complex that has not been possible to develop for indications requiring parenteral administration. We have resolved this issue by synthesizing Cu(DDC)(2) inside liposomes. DDC crosses the liposomal lipid bilayer, reacting with the entrapped copper; a reaction that can be observed through a colour change as the solution goes from a light blue to dark brown. This method is successfully applied to other CDCs including the anti-parasitic drug clioquinol, the natural product quercetin and the novel targeted agent CX-5461. Our method provides a simple, transformative solution enabling, for the first time, the development of CDCs as viable candidate anticancer drugs; drugs that would represent a brand new class of therapeutics for cancer patients.

  • 713.
    Weibull, Emilie
    et al.
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Bai, Yunpeng
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Jönsson, Håkan
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Andersson Svahn, Helen
    KTH, School of Biotechnology (BIO), Proteomics and Nanobiotechnology. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Interfacing picoliter droplet microfluidics with addressable μl-compartments using FACS2013In: 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013, 2013, Vol. 3, p. 1632-1634Conference paper (Refereed)
    Abstract [en]

    We present a high-throughput technique to interface picoliter droplet microfluidics for single cell analysis with a macro scale accessible array platform by the addition of an agarose gelling agent to droplets and patterned positioning of the resulting hydrogel beads using a fluorescence activated cell sorter (FACS). This resulted in a pattern with 95 % single bead accuracy. Agarose beads containing eGFP expressing E. Coli were single sorted into microwells and E. coli growth was monitored over time.

  • 714. Wesselmark, M.
    et al.
    Wickman, B.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    The impact of iridium on the stability of platinum on carbon thin-filmmodel electrodes2013In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 111, p. 152-159Article in journal (Refereed)
    Abstract [en]

    Increasing the stability and lifetime of the electrodes is one of the most important factors in order to realise a large scale use of polymer electrolyte membrane fuel cells (PEMFC). By using well-defined thin-film model electrodes, the stability of Pt and Pt on Ir were examined as cathode catalysts in a single cell PEMFC setup. The electrodes were fabricated by evaporating thin layers of Pt and Pt on Ir onto the microporous layer of a gas diffusion layer. The amount of Pt deposited was equivalent to 3 nm (about 6.3 mu g cm(-2)) and the amount of Ir was varied between 1.5 nm and 20 nm (between 3.4 mu g cm(-2) and 45.3 mu g cm(-2)). All samples with Ir showed an increased stability over samples with sole Pt during cyclic corrosion test between 0.6V and 1.2V vs. the reversible hydrogen electrode. For thin layers of Ir, the initial activity for the oxygen reduction reaction was equal to or superior to that of sole Pt but for thicker Ir films it was somewhat lower. Hydrogen underpotential deposition and CO stripping were used to estimate the electrochemical surface area during the experiments and physical characterisation using scanning electron microscopy and X-ray photoelectron spectroscopy were used to determine the structure of the samples. The results suggest that Ir can stabilise Pt in the cathode electrode.

  • 715.
    Westerlund, Annie M.
    et al.
    KTH, School of Engineering Sciences (SCI), Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Harpole, Tyler
    KTH, School of Engineering Sciences (SCI), Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Blau, C.
    Delemotte, Lucie
    KTH, School of Engineering Sciences (SCI), Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Inference of Calmodulin's Ca2+-Dependent Free Energy Landscapes via Gaussian Mixture Model Validation2018In: Journal of Chemical Theory and Computation, ISSN 1549-9618, E-ISSN 1549-9626, Vol. 14, no 1, p. 63-71Article in journal (Refereed)
    Abstract [en]

    A free energy landscape estimation method based on the well-known Gaussian mixture model (GMM) is used to compare the efficiencies of thermally enhanced sampling methods with respect to regular molecular dynamics. The simulations are carried out on two binding states of calmodulin, and the free energy estimation method is compared with other estimators using a toy model. We show that GMM with cross-validation provides a robust estimate that is not subject to overfitting. The continuous nature of Gaussians provides better estimates on sparse data than canonical histogramming. We find that diffusion properties determine the sampling method effectiveness, such that diffusion-dominated apo calmodulin is most efficiently sampled by regular molecular dynamics, while holo calmodulin, with its rugged free energy landscape, is better sampled by enhanced sampling methods.

  • 716. Wibe, Atle
    et al.
    Borg Karlsson, Anna-Karin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. Univ Tartu, Inst Technol, Sect Organ Chem, Estonia.
    Cross, Jerry
    Bichao, Helena
    Fountain, Michelle
    Liblikas, Ilme
    Sigsgaard, Lene
    Combining 1,4-dimethoxybenzene, the major flower volatile of wild strawberry Fragaria vesca, with the aggregation pheromone of the strawberry blossom weevil Anthonomus rubi improves attraction2014In: Crop Protection, ISSN 0261-2194, E-ISSN 1873-6904, Vol. 64, p. 122-128Article in journal (Refereed)
    Abstract [en]

    The aggregation pheromone of strawberry blossom weevil [Anthonomus rubi Herbst (Col.: Curculionidae)1, a 1:4:1 blend of Grandlure I, II and racemic lavadulol, has been available for pest monitoring for several years but shows low attractancy. Attempts to control A. rubi using the pheromone alone were also unsuccessful. This paper reports the finding that addition of the major flower volatile from wild strawberry flowers [Fragaria vesca L. (Rosaceae)], 1,4-dimethoxybenzene (comprising 98% of the volatiles emitted from wild strawberry flowers), to the aggregation pheromone increased trap catches by over two fold compared to the pheromone alone. There was no significant difference between the response of overwintered or summer emerged adults. Field trials in 2007-2008 in central and southern Norway, Denmark and southern England used green funnel traps with white cross vanes for the evaluations. (-)-Germacrene D, previously shown to be emitted by plants in increased amounts in the presence of pheromone producing weevils, did not improve trap catches. Thus, the combined use of the aggregation pheromone and 1,4-dimethoxybenzene is promising for improved monitoring and possibly control of this important pest of strawberry.

  • 717. Wieland, D. C. F.
    et al.
    Degen, P.
    Zander, T.
    Gayer, S.
    Raj, A.
    An, J.
    Dédinaité, Andra A
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, School of Chemical Sciences and Engineering, Department of Chemistry, Surface and Corrosion Science.
    Claesson, Per M.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. Department of Chemistry Surface and Corrosion Science, KTH Royal Institute of Technology.
    Willumeit-Römer, R.
    Structure of DPPC-hyaluronan interfacial layers-effects of molecular weight and ion composition2016In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 12, no 3, p. 729-740Article in journal (Refereed)
    Abstract [en]

    Hyaluronan and phospholipids play an important role in lubrication in articular joints and provide in combination with glycoproteins exceptionally low friction coefficients. We have investigated the structural organization of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) Langmuir layers at the solution-air interface at different length scales with respect to the adsorption of hyaluronan (HA). This allows us to assemble a comprehensive picture of the adsorption and the resulting structures, and how they are affected by the molecular weight of HA and the presence of calcium ions. Brewster angle microscopy and grazing incident diffraction were used to determine the lateral structure at the micro- and macro scale. The data reveals an influence of HA on both the macro and micro structure of the DPPC Langmuir layer, and that the strength of this effect increases with decreasing molecular weight of HA and in presence of calcium ions. Furthermore, from X-ray reflectivity measurements we conclude that HA adsorbs to the hydrophilic part of DPPC, but data also suggest that two types of interfacial structures are formed at the interface. We argue that hydrophobic forces and electrostatic interactions play important rules for the association between DPPC and HA. Surface pressure area isotherms were used to determine the influence of HA on the phase behavior of DPPC while electrophoretic mobility measurements were used to gain insight into the binding of calcium ions to DPPC vesicles and hyaluronan.

  • 718. Wieland, D. C. F.
    et al.
    Garamus, V. M.
    Zander, T.
    Krywka, C.
    Wang, M.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor. Department of Chemistry, Surface and Corrosion Science, KTH Royal Institute of Technology.
    Dédinaité, Andra A
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Life Science. KTH Royal Institute of Technology, School of Chemical Sciences and Engineering, Department of Chemistry, Surface and Corrosion Science.
    Claesson, Per M.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Material och ytteknik. Department of Chemistry Surface and Corrosion Science, KTH Royal Institute of Technology.
    Willumeit-Römera, R.
    Studying solutions at high shear rates: A dedicated microfluidics setup2016In: Journal of Synchrotron Radiation, ISSN 0909-0495, E-ISSN 1600-5775, Vol. 23, no 2, p. 480-486Article in journal (Refereed)
    Abstract [en]

    The development of a dedicated small-angle X-ray scattering setup for the investigation of complex fluids at different controlled shear conditions is reported. The setup utilizes a microfluidics chip with a narrowing channel. As a consequence, a shear gradient is generated within the channel and the effect of shear rate on structure and interactions is mapped spatially. In a first experiment small-angle X-ray scattering is utilized to investigate highly concentrated protein solutions up to a shear rate of 300000 s-1. These data demonstrate that equilibrium clusters of lysozyme are destabilized at high shear rates.

  • 719. Wigestrand, Mattis B.
    et al.
    Stenberg, Mia
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Waalas, S Ivar
    Fonnum, Frode
    Andersson, Patrik
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Non-dioxin-like PCBs inhibit [3H]WIN-35,428 binding to dopamine active transporter:  a structure activity relationship study2013In: Naunyn-Schmiedeberg's Archives of Pharmacology, ISSN 0028-1298, E-ISSN 1432-1912Article in journal (Other academic)
  • 720.
    Willgert, Markus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Solid Polymer Lithium-ion Conducting Electrolytes for Structural Batteries2012Licentiate thesis, comprehensive summary (Other academic)
  • 721.
    Willighagen, Egon
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Pharmaceutical Biosciences.
    3D Molecular Representations2010In: Handbook of Chemoinformatics Algorithms / [ed] J-l. Faulon, A. Bender, Boca Raton: CRC Press , 2010Chapter in book (Other academic)
  • 722. Willighagen, Egon
    Groovy Cheminformatics with the Chemistry Development Kit2011 (ed. 1.3.8-0)Book (Other (popular science, discussion, etc.))
  • 723.
    Winberg, Mikael
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education.
    Learning by computer-simulated laboratory exercises – effects on learning outcomes.2001Conference paper (Other academic)
  • 724.
    Winberg, Mikael
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education.
    Using PCA for analysis of questionnaires, a journey into the affective domain.2001Conference paper (Refereed)
  • 725.
    Winberg, Mikael
    et al.
    Umeå University, Faculty of Science and Technology, Department of Science and Mathematics Education. Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Berg, A
    Lunberg, B
    Computer simulated acid-base titrations as prelab: effects on learning outcome2001Conference paper (Refereed)
  • 726.
    Winberg, Mikael
    et al.
    Umeå University, Faculty of Teacher Education, Mathematics, Technology and Science Education.
    Berg, Anders
    Umeå University, Faculty of Teacher Education, Mathematics, Technology and Science Education.
    Students' cognitive focus during a chemistry laboratory exercise: Effects of a computer simulated prelab2007In: Journal of research in science teaching, ISSN 0022-4308, Vol. 44, no 8, p. 1098-2736Article in journal (Refereed)
    Abstract [en]

    To enhance the learning outcomes achieved by students, learners undertook a computer-simulated activity based on an acid-base titration prior to a university-level chemistry laboratory activity. Students were categorized with respect to their attitudes toward learning. During the laboratory exercise, questions that students asked their assistant teachers were used as indicators of cognitive focus. During the interviews, students' frequency and level of spontaneous use of chemical knowledge served as an indicator of knowledge usability. Results suggest that the simulation influenced students toward posing more theoretical questions during their laboratory work and, regardless of attitudes, exhibiting a more complex, correct use of chemistry knowledge in their interviews. A more relativistic student attitude toward learning was positively correlated with interview performance in both the control and treatment groups.

  • 727.
    Winberg, T. Mikael
    et al.
    Umeå University, Faculty of Teacher Education, Mathematics, Technology and Science Education.
    Hedman, Leif
    Umeå University, Faculty of Social Sciences, Department of Psychology.
    Student attitudes toward learning, level of pre-knowledge and instruction type in a computer-simulation: effects on flow experiences and perceived learning outcomes2008In: Instructional science, ISSN 0020-4277, E-ISSN 1573-1952, Vol. 36, no 4, p. 269-287Article in journal (Refereed)
    Abstract [en]

    Attitudes toward learning (ATL) have been shown to influence students’ learning outcomes. However, there is a lack of knowledge about the ways in which the interaction between ATL, the learning situation, and the level of students’ prior knowledge influence affective reactions and conceptual change. In this study, a simulation of acid-base titrations was examined to assess the impact of instruction format, level of prior knowledge and students’ ATL on university-level students, with respect to flow experiences (Csikszentmihalyi, 1990) and perceived conceptual change. Results show that the use of guiding instructions was correlated with a perceived conceptual change and high levels of “Challenge,” “Enjoyment,” and “Concentration,” but low sense of control during the exercise. Students who used the open instructions scored highly on the “Control flow” component, but their perceived learning score was lower than that for the students who used the guiding instructions. In neither case did students’ ATL or their pre-test results contribute strongly to students’ flow experiences or their perceived learning in the two different learning situations.

  • 728. Wu, Zhihua
    et al.
    Lundberg, Pontus
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Zhang, Yuning
    Zeng, Xianghui
    Feliu, Neus
    Fadeel, Bengt
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Nyström, Andreas M.
    Engineering biocompatible drug delivery systems based on dendritic polymers2012In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 243Article in journal (Other academic)
  • 729.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Cellulose Fibers and Fibrils as Templates for the Layer-by-Layer (LbL) Technology2012In: Multilayer Thin Films: Assembly of Nanocomposite Materials: Second Edition, Wiley-VCH Verlagsgesellschaft, 2012, 2, Vol. 1, p. 171-187Chapter in book (Refereed)
  • 730.
    Wågberg, Lars
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Fall, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Nyström, Gustav
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindström, Stefan
    Colloidal stability of nanofibrillated cellulose: Models, characterization, and assembly of fibrils2014In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 247, p. 124-CELL-Article in journal (Other academic)
  • 731. Xia, Na
    et al.
    Yang, Yuanqing
    Li, Qiang
    Qiu, Min
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Optics and Photonics, OFO. Zhejiang University, China.
    Tunable unidirectional long-range surface plasmon polaritons launching based on nanoslits2015In: AOPC 2015: MICRO/NANO OPTICAL MANUFACTURING TECHNOLOGIES; AND LASER PROCESSING AND RAPID PROTOTYPING TECHNIQUES, SPIE - International Society for Optical Engineering, 2015, article id UNSP 96730WConference paper (Refereed)
    Abstract [en]

    We propose a tunable unidirectional long-range surface plasmon polaritons (LRSPP) launcher based on subwavelength metallic nanoslits in the visible range. The direction of the generated LRSPPs could be tuned simply by varying the incident angles. The extinction ratio reaches up to 28 dB with a wide angular width of 30 degrees. The influences of the launcher geometry on its performance are investigated in this study as well. The broadband property of the launcher is also demonstrated.

  • 732. Xiang, W.
    et al.
    Han, X.
    Astorsdotter, Jennifer
    KTH.
    Farrauto, R.
    Catalysts promoted with niobium oxide for air pollution abatement2017In: Catalysts, ISSN 2073-4344, Vol. 7, no 5, article id 144Article in journal (Refereed)
    Abstract [en]

    Pt-containing catalysts are currently used commercially to catalyze the conversion of carbon monoxide (CO) and hydrocarbon (HC) pollutants from stationary chemical and petroleum plants. It is well known that Pt-containing catalysts are expensive and have limited availability. The goal of this research is to find alternative and less expensive catalysts to replace Pt for these applications. This study found that niobium oxide (Nb2O5), as a carrier or support for certain transition metal oxides, promotes oxidation activity while maintaining stability, making them candidates as alternatives to Pt. The present work reports that the orthorhombic structure of niobium oxide (formed at 800◦C in air) promotes Co3O4 toward the oxidation of both CO and propane, which are common pollutants in volatile organic compound (VOC) applications. This was a surprising result since this structure of Nb2O5 has a very low surface area (about 2 m2/g) relative to the more traditional Al2O3 support, with a surface area of 150 m2/g. The results reported demonstrate that 1% Co3O4/Nb2O5 has comparable fresh and aged catalytic activity to 1% Pt/γ-Al2O3 and 1% Pt/Nb2O5. Furthermore, 6% Co3O4/Nb2O5 outperforms 1% Pt/Al2O3 in both catalytic activity and thermal stability. These results suggest a strong interaction between niobium oxide and the active component—cobalt oxide—likely by inducing an oxygen defect structure with oxygen vacancies leading to enhanced activity toward the oxidation of CO and propane.

  • 733. Xie, Fei
    et al.
    Nylander, Tommy
    Piculell, Lennart
    Utsel, Simon
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Åkesson, Torbjörn
    Forsman, Jan
    Polyelectrolyte Adsorption on Solid Surfaces: Theoretical Predictions and Experimental Measurements2013In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 29, no 40, p. 12421-12431Article in journal (Refereed)
    Abstract [en]

    This work utilizes a combination of theory and experiments to explore the adsorption of two different cationic polyelectrolytes onto oppositely charged silica surfaces at pH 9. Both polymers, poly(diallyldimethylammonium chloride), PDADMAC, and poly(4-vinyl N-methylpyridinium iodide), PVNP, are highly charged and highly soluble in water. Another important aspect is that a silica surface carries a relatively high surface charge density at this pH level. This means that we have specifically chosen to investigate adsorption under conditions where electrostatics can be expected to dominate the interactions. Of specific focus in this work is the response of the adsorption to the addition of simple salt (i.e., a process where electrostatics is gradually screened out). Theoretical predictions from a recently developed correlation-corrected classical density functional theory for polyelectrolytes are evaluated by direct quantitative comparisons with corresponding experimental data, as obtained by ellipsometry measurements. We find that, at low concentrations of simple salt, the adsorption increases with ionic strength, reaching a maximum at intermediate levels (about 200 mM). The adsorption then drops but retains a finite level even at very high salt concentrations, indicating the presence of nonelectrostatic contributions to the adsorption. In the theoretical treatment, the strength of this relatively modest but otherwise largely unknown nonelectrostatic surface affinity was estimated by matching predicted and experimental slopes of adsorption curves at high ionic strength. Given these estimates for the nonelectrostatic part, experimental adsorption data are essentially captured with quantitative accuracy by the classical density functional theory.

  • 734. Xie, Yongshu
    et al.
    Wei, Pingchun
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Hong, Tao
    Zhang, Kai
    Furuta, Hiroyuki
    Macrocycle Contraction and Expansion of a Dihydrosapphyrin Isomer2013In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 135, no 51, p. 19119-19122Article in journal (Refereed)
    Abstract [en]

    Cyclization of a pentapyrrane with two terminal beta-linked pyrroles afforded a dihydrosapphyrin isomer (1) with the pyrroles linked in a unique beta,alpha-alpha,beta mode, which was rather reactive, and thus it readily underwent a ring-contracted rearrangement to a pyrrolyl norrole (2), and succeeding ring expansion to a terpyrrole-containing isosmaragdyrin analogue (4). 1, 2, and 4 contain the internal ring pathways with a minimum of 17, 15, and 16 atoms, respectively. 1, 2, and 4 are almost nonfluorescent, whereas the complex of 2 with Zn2+ shows a distinct NIR emission peak at 741 nm. The unprecedented pyrrole transformation chemistry by confusion approach is illustrated.

  • 735.
    Xiong, Ruisheng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Arkhypchuk, Anna I.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Kovacs, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Orthaber, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Borbas, K. Eszter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Directly linked hydroporphyrin dimers2016In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 52, no 58, p. 9056-9058Article in journal (Refereed)
    Abstract [en]

    Directly linked hydroporphyrin (chlorin) dimers were accessed regioselectively from bromochlorins. Versatile 15-borylated chlorins were prepared in excellent yield via Miyaura borylation. Suzuki coupling yielded meso-beta-linked homo- and heterodimers, and meso-blinked dimers. The photophysical and electrochemical properties of the dimers are reported.

  • 736.
    Xiong, Ruisheng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Borbas, K. Eszter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Mild Microwave-Assisted Synthesis of Dipyrromethanes and Their Analogues2015In: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, Vol. 26, no 4, p. 484-488Article in journal (Refereed)
    Abstract [en]

    The Mannich reaction between pyrroles or indoles and Eschenmoser's salt (dimethylmethylideneammonium iodide) forms N,N-dimethylamino-methylated derivatives in good to excellent yields. The reaction is highly regioselective, and for pyrroles both 2- and 3-substituted derivatives could be obtained. The N,N-dimethylaminomethylpyrroles and indoles underwent substitution with pyrrole under microwave irradiation, affording the appropriate dipyrromethanes, N-confused, and indolo-dipyrromethanes in moderate to excellent overall yield.

  • 737.
    Xu, Chao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Lindgren, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Philippe, Bertrand
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Molecular and Condensed Matter Physics.
    Gorgoi, Mihaela
    Helmholtz Zentrum Berlin Germany.
    Björefors, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Gustafsson, Torbjörn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Improved Performance of the Silicon Anode for Li-Ion Batteries: Understanding the Surface Modification Mechanism of Fluoroethylene Carbonate as an Effective Electrolyte Additive2015In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 27, no 7, p. 2591-2599Article in journal (Refereed)
    Abstract [en]

    Silicon as a negative electrode material for lithium-ion batteries has attracted tremendous attention due to its high theoretical capacity, and fluoroethylene carbonate (FEC) was used as an electrolyte additive, which significantly improved the cyclability of silicon-based electrodes in this study. The decomposition of the FEC additive was investigated by synchrotron-based X-ray photoelectron spectroscopy (PES) giving a chemical composition depth-profile. The reduction products of FEC were found to mainly consist of LiF and -CHF-OCO2-type compounds. Moreover, FEC influenced the lithium hexafluorophosphate (LiPF6) decomposition reaction and may have suppressed further salt degradation. The solid electrolyte interphase (SEI) formed from the decomposition of ethylene carbonate (EC) and diethyl carbonate (DEC), without the FEC additive present, covered surface voids and lead to an increase in polarization. However, in the presence of FEC, which degrades at a higher reduction potential than EC and DEC, instantaneously a conformal SEI was formed on the silicon electrode. This stable SEI layer sufficiently limited the emergence of large cracks and preserved the original surface morphology as well as suppressed the additional SEI formation from the other solvent. This study highlights the vital importance of how the chemical composition and morphology of the SEI influence battery performance.

  • 738. Xu, Jing
    et al.
    Marsac, Remi
    Costa, Dominique
    Cheng, Wei
    Wu, Feng
    Boily, Jean-Francois
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hanna, Khalil
    Co-Binding of Pharmaceutical Compounds at Mineral Surfaces: Molecular Investigations of Dimer Formation at Goethite/Water Interfaces2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 15, p. 8343-8349Article in journal (Refereed)
    Abstract [en]

    The emergence of antibiotic and anti-inflammatory agents in aquatic and terrestrial systems is becoming a serious threat to human and animal health worldwide. Because pharmaceutical compounds rarely exist individually in nature, interactions between various compounds can have unforeseen effects on their binding to mineral surfaces. This work demonstrates this important possibility for the case of two typical antibiotic and anti-inflammatory agents (nalidixic acid (NA) and niflumic acid (NFA)) bound at goethite (alpha FeOOH) used as a model mineral surface. Our multidisciplinary study, which makes use of batch sorption experiments, vibration spectroscopy and periodic density functional theory calculations, reveals enhanced binding of the otherwise weakly bound NFA caused by unforeseen intermolecular interactions with mineral-bound NA. This enhancement is ascribed to the formation of a NFA NA dimer whose energetically favored formation (-0.5 eV compared to free molecules) is predominantly driven by van der Waals interactions. A parallel set of efforts also showed that no. cobinding occurred with sulfamethoxazole (SMX) because of the lack of molecular interactions with coexisting contaminants. As such, this article raises the importance of recognizing drug cobinding, and lack of cobinding, for predicting and developing policies on the fate of complex mixtures of antibiotics and anti-inflammatory agents in nature.

  • 739. Yager, Tom
    et al.
    Webb, Matthew J.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Yakimova, Rositsa
    Lara-Avila, Samuel
    Kubatkin, Sergey
    High mobility epitaxial graphene devices via aqueous-ozone processing2015In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 106, no 6, article id 063503Article in journal (Refereed)
    Abstract [en]

    We find that monolayer epitaxial graphene devices exposed to aggressive aqueous-ozone processing and annealing became cleaner from post-fabrication organic resist residuals and, significantly, maintain their high carrier mobility. Additionally, we observe a decrease in carrier density from inherent strong n-type doping to extremely low p-type doping after processing. This transition is explained to be a consequence of the cleaning effect of aqueous-ozone processing and annealing, since the observed removal of resist residuals from SiC/G enables the exposure of the bare graphene to dopants present in ambient conditions. The resulting combination of charge neutrality, high mobility, large area clean surfaces, and susceptibility to environmental species suggest this processed graphene system as an ideal candidate for gas sensing applications. (C) 2015 AIP Publishing LLC.

  • 740. Yan, H.
    et al.
    Zhu, L.
    Li, X.
    Kwok, A.
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Zhao, Y.
    Photothermal-responsive [2]rotaxanes2013In: RSC Advances, ISSN 2046-2069, Vol. 3, no 7, p. 2341-2350Article in journal (Refereed)
    Abstract [en]

    Three photothermal-responsive α-cyclodextrin-based [2]rotaxanes were prepared via the copper(i)-catalyzed azide-alkyne cycloaddition, in which the α-cyclodextrin ring was threaded onto the azobenzene dumbbell component. The difference between the three [2]rotaxanes are the length of the ethylene glycol repeating chains connected between the azobenzene and triazole units in the dumbbell components. The α-cyclodextrin rings in the [2]rotaxanes can be reversibly switched between the azobenzene unit and triazole/ethylene glycol unit driven by the trans-cis isomerization of the azobenzene unit. The trans-to-cis isomerization of the azobenzene unit under UV light irradiation (365 nm) leads the α-cyclodextrin ring moving to the triazole/ethylene glycol unit, while the cis-to-trans isomerization of the azobenzene unit under either visible light irradiation or heating enables the α-cyclodextrin ring shuttling back to the azobenzene station. The different ethylene glycol repeating chains in the [2]rotaxanes can affect (1) the isomerization rates of the azobenzene units, i.e. the longer the chain, the faster the isomerization rate, and (2) fluorescent quantum yields of the [2]rotaxanes, i.e. the longer the chain, the lower the fluorescent quantum yield. In addition, the quantum yields of the [2]rotaxanes were enhanced by UV light irradiation and decreased back upon visible light irradiation or heating at 65 °C. The current research provides a fundamental understanding of the working mechanism for photothermal-responsive [2]rotaxanes.

  • 741.
    Yan, Jinyue
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes. Mälardalen University, Sweden .
    Chou, S. K.
    Dahlquist, E.
    Li, H.
    Innovative Research For Sustainable Energy Systems2015In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 12, no 3, p. 191-191Article in journal (Other academic)
  • 742. Yang, Fengmei
    et al.
    Sun, Weiwei
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering. Uppsala University, Sweden .
    Li, Yuhan
    Yuan, Haiyan
    Dong, Zhiyong
    Li, Huanhuan
    Tian, Jumei
    Zheng, Yiying
    Zhang, Jingping
    Li2FePO4F and its metal-doping for Li-ion batteries: an ab initio study2014In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 4, no 91, p. 50195-50201Article in journal (Refereed)
    Abstract [en]

    The electrochemical properties of three isotopic Li2FePO4F compounds, as cathode materials under different space groups Pbcn, P (1) over bar and Pnma were investigated using first principle calculations. Their structures and average open circuit voltages for step delithiation reactions were explored, and the results are in good agreement with the reported experimental data. We estimate the substitution effect of Fe by Co in Pnma-Li2FePO4F. The substitution of Fe by Co in Li2Fe1-xCoxPO4F may enhance the discharge potential of the materials, and the rate of its volume change during the redox process is between 0.6% and 2.1%. Furthermore, from the projected density of states for Li2Fe0.5Co0.5PO4F, we found strong hybridization for Fe-3d and Co-3d bands near the Fermi level, which implies that the Co-doped Li2Fe1-xCoxPO4F may possess better electronic conductivity than the pure phase.

  • 743. Yang, Jie
    et al.
    Yu, Xinhai
    Yan, Jinyue
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Tu, Shan-Tung
    CO2 Capture Using Amine Solution Mixed with Ionic Liquid2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 7, p. 2790-2799Article in journal (Refereed)
    Abstract [en]

    It is a focus to reduce the energy consumption and operating cost of CO2 capture from low-pressure flue gas streams of power plants using an aqueous amine-based absorbent. In this study, CO2 capture experiments were conducted in an absorption-desorption loop system using amine-based absorbents. The gas mixture containing CO2, O-2, SO2, and N-2 in the composition range of flue gas from coal-fired power plant after flue gas desulfurization was selected as the feed gas. For an aqueous amine solution, the largest contribution to monoethanolamine (MEA) loss was made by evaporation during desorption, followed by the formation of sulfate and heat-stable salts. To reduce MBA loss and meanwhile decrease the energy consumption during CO2 desorption, an aqueous amine solution mixed with ionic liquid (30 wt % MBA + 40 wt % [bmim][BF4] + 30 wt % H2O) was proposed. The energy consumption of the mixed ionic liquid solution for absorbent regeneration was 37.2% lower than that of aqueous MEA solution. The MEA loss per ton of captured CO2 for the mixed solution was 1.16 kg, which is much lower than that of 3.55 kg for the aqueous amine solution. No ionic liquid loss was detected. In addition, the mixed ionic liquid solution showed a low viscosity of 3.54 mPa s at 323 K, indicating that the ionic liquid disadvantage of high viscosity can be overcome for absorbent delivery of CO2 capture.

  • 744. Yang, Lei
    et al.
    Zhang, Jinbao
    Shen, Yang
    Park, Byung-Wook
    Bi, Dongqin
    Häggman, Leif
    Johansson, Erik M. J.
    Boschloo, Gerrit
    Hagfeldt, Anders
    Vlachopoulos, Nick
    Snedden, Alan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jarboui, Adel
    Chams, Amani
    Perruchot, Christian
    Jouini, Mohamed
    New Approach for Preparation of Efficient Solid-State Dye-Sensitized Solar Cells by Photoelectrochemical Polymerization in Aqueous Micellar Solution2013In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 4, no 23, p. 4026-4031Article in journal (Refereed)
    Abstract [en]

    Hereby, we present a new, cost-effective, and environmentally friendly method of preparing an efficient solid-state dye-sensitized solar cell (sDSC) using a PEDOT conducting polymer as the hole conductor and a recently developed organic sensitizer. PEDOT is generated and deposited on the dye-sensitized TiO2 electrode by in situ photoelectropolymerization of bis-EDOT in aqueous micellar solution. The advantages of this approach are the use of water as the solvent and the obtainment of a sDSC simply by adding a silver layer on the as-obtained polymer film deposited on dye/TiO2 without the need for electrolytic solution. The sDSC containing the film prepared as above is compared to those where the organic dye is used to generate the same polymer film but in organic solvent. The energy conversion efficiency values of the two cells appear comparable, 4.8% for sDSC prepared in the aqueous-phase polymerized PEDOT and 6% for the sDSC prepared with in organic-phase polymerized PEDOT.

  • 745.
    Yang, Li
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Mihali, Viorica-Alina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Karlsson, Christoffer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Brandell, Daniel
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Conjugated polymers as anodes in organic matter based batteries2014Conference paper (Other academic)
  • 746.
    Yang, Miao
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Barreiro Fidalgo, Alexandre
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Sundin, Sara
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Inhibition of radiation induced dissolution of UO2 by sulfide-A comparison with the hydrogen effect2013In: Journal of Nuclear Materials, ISSN 0022-3115, E-ISSN 1873-4820, Vol. 434, no 1-3, p. 38-42Article in journal (Refereed)
    Abstract [en]

    In this work we have studied the influence of H2S on radiation induced dissolution of spent nuclear fuel using simple model systems. The reaction between H2O2 and H2S/HS- has been studied experimentally as well as the effect of H2S/HS - on γ-radiation induced dissolution of a UO2 pellet. The experiments clearly show that the reaction of H2O 2 and H2S/HS- is fairly rapid and that H 2O2 and H2S/HS- stoichiometry is favorable for inhibition. Radiolysis experiments show that H2S/ HS- can effectively protect UO2 from oxidative dissolution. The effect depends on sulfide concentration in combination with dose rate. Autoclave experiments were also conducted to study the role of H 2S/HS- in the reduction of U(VI) in the presence and absence of H2 and Pd particles in anoxic aqueous solution. The aqueous solutions were pressurized with H2 or N2 and two different concentrations of H2S/HS- were used in the presence and absence of Pd. No catalytic effect of Pd on the U(VI) reduction by H2S/HS- could be found in N2 atmosphere. U(VI) reduction was found to be proportional to H2S/HS- concentration in H2 and N2 atmosphere. It is clearly shown the Pd catalyzed H2 effect is more powerful than the effect of H2S/HS-. H2S/HS- poisoning of the Pd catalyst is not observed under the present conditions.

  • 747.
    Yang Nilsson, Ting
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Wagner, Michal
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials2015In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 8, no 23, p. 4081-4085Article in journal (Refereed)
    Abstract [en]

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by P-31 nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70mAhg(-1)). The modification of softwood and hardwood lignin derivatives yielded 50% and 23% higher charge capacity than the original lignin, respectively.

  • 748. Yang, Yong
    et al.
    Wang, Mei
    Xue, Liqin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Zhang, Fengbo
    Chen, Lin
    Ahlquist, Mårten S. G.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. State Key Laboratory of Fine Chemicals, DUT-KTH Education and Research Centre on Molecular Devices, Dalian University of Technology (DUT), China.
    Nickel Complex with Internal Bases as Efficient Molecular Catalyst for Photochemical H-2 Production2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 10, p. 2889-2897Article in journal (Refereed)
    Abstract [en]

    A Ni complex with internal bases that contain bipyridine-derived ligands, [Ni(L)(2)(H2O)(2)](BF4)(2) ([1](BF4)(2), L=2-(2-pyridyl)-1,8-naphthyridine), and a reference complex that bears analogous bipyridine-derived ligands but without an internal base, [Ni(L)(3)](BF4)(2) ([2](BF4)(2), L=2-(2-pyridyl)quinoline), were synthesized and characterized. The electrochemical properties of these complexes were studied in CH3CN, H2O, and a mixture of EtOH/H2O. The fluorescence spectroscopic studies suggest that both dynamic and the sphere-of-action static quenching exist in the fluorescein Fl(2-)/[1](2+) and Fl(2-)/[2](2+) systems. These noble-metal-free molecular systems were studied for photocatalytic H-2 generation. Under optimal conditions, the turnover number of H-2 evolution reaches 3230 based on [1](2+), whereas [2](2+) displays only approximately one third of the turnover of [1](2+). A plausible mechanism for the catalytic H-2 generation by [1](2+) is presented based on DFT calculations.

  • 749. Ye, Chen-Qing
    et al.
    Hu, Rong-Gang
    Dong, Shi-Gang
    Zhang, Xiao-Juan
    Hou, Rui-Qing
    Du, Rong-Gui
    Lin, Chang-Jian
    Pan, Jin-Shan
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science.
    EIS analysis on chloride-induced corrosion behavior of reinforcement steel in simulated carbonated concrete pore solutions2013In: Journal of Electroanalytical Chemistry, ISSN 1572-6657, Vol. 688, p. 275-281Article in journal (Refereed)
    Abstract [en]

    The corrosion behavior of reinforcement steel in simulated carbonated concrete pore (SCCP) solution containing different concentrations of chloride was studied by electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) measurements simultaneously, and the topographies of the steel specimens and the elemental distribution at corrosion area were examined by scanning electron microscope (SEM)/electron microprobe analysis (EMPA). The results showed the capacitive loop and polarization resistance decreased with chloride increasing. Furthermore, when the chloride concentration reached a critical value, the Bode plots obviously exhibited two phase angle peaks indicating two time constants. However, when the chloride content exceeded a critical value, the phase angle peaks decreased to one phenomenal peak. An equivalent circuit with two RC loops was used to characterize the corrosion behavior of reinforcement steel in SCCP solution according to the measurements of EIS. Based on the dependence of the equivalent circuit elements on chloride content and immersion time, the formation, growth and breakdown of passive film of the steel were discussed. It was found that the EIS evaluation of corrosion behavior for reinforcement steel in SCCP solution was good agreement with the LPR and SEM measurements. The EMPA mapping revealed MnS inclusions at steel surface play a leading role in the initiation of pitting corrosion.

  • 750.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Stockholm University.
    Organohalogen contaminants in wildlife from the Yangtze River Delta: Development of methods and assessments of legacy and emerging persistent organic pollutants2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rapid economic development has occurred during the past few decades in China with the Yangtze River Delta (YRD) area as one of the most progressive areas. The urbanization, industrialization, agricultural and aquaculture activities result in extensive production and application of chemicals. Organohalogen contaminants (OHCs) have been widely used as i.e. pesticides, flame retardants and plasticizers. They are persistent, bioaccumulative and pose a potential threat to ecosystem and human health. However, limited research has been conducted in the YRD with respect to chemicals environmental exposure.

    The main objective of this thesis is to investigate the contamination level, distribution pattern and sources of OHCs in the YRD. Wildlife from different habitats are used to indicate the environmental pollution situation, and evaluate selected matrices for use in long term biomonitoring to determine the environmental stress the contamination may cause. In addition, a method is developed for dicofol analysis. Moreover, a specific effort is made to introduce statistic power analysis to assist in optimal sampling design.

    The thesis results show extensive contamination of OHCs in wildlife in the YRD. The occurrences of high concentrations of chlorinated paraffins (CPs) are reported in wildlife, in particular in terrestrial species, (i.e. short-tailed mamushi snake and peregrine falcon). Impurities and byproducts of pentachlorophenol products, i.e. polychlorinated diphenyl ethers (PCDEs) and hydroxylated polychlorinated diphenyl ethers (OH-PCDEs) are identified and reported for the first time in eggs from black-crowned night heron and whiskered tern. High concentrations of octachlorodibenzo-p-dioxin (OCDD) are determined in these samples. The toxic equivalents (TEQs) of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs) are at mean levels of 300 and 520 pg TEQ g-1lw (WHO2005 TEQ) in eggs from the two bird species, respectively. This is two orders of magnitude higher than European Union (EU) regulation limit in chicken eggs. Also, a novel pattern of polychlorinated biphenyls (PCBs) with octa- to decaCBs, contributing to as much as 20% of total PCBs therein, are reported in birds. The legacy POPs shows a common characteristic with relatively high level of organochlorine pesticides (i.e. DDT, hexacyclohexanes (HCHs) and Mirex), indicating historic applications. In contrast, rather low concentrations are shown of industrial chemicals such as PCBs and polybrominated diphenyl ethers (PBDEs).

    A refined and improved analytical method is developed to separate dicofol from its major decomposition compound, 4,4’-dichlorobenzophenone. Hence dicofol is possible to assess as such. Statistic power analysis demonstrates that sampling of sedentary species should be consistently spread over a larger area to monitor temporal trends of contaminants in a robust manner.

    The results presented in this thesis show high CPs and OCDD concentrations in wildlife. The levels and patterns of OHCs in YRD differ from other well studied areas of the world. This is likely due to the extensive production and use of chemicals in the YRD. The results strongly signal the need of research biomonitoring programs that meet the current situation of the YRD. Such programs will contribute to the management of chemicals and environment in YRD, with the potential to grow into the human health sector, and to expand to China as a whole.

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