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  • 301. Makarova, I. V.
    et al.
    Kharitonov, D. S.
    Dobryden', Illia B.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Chernik, A. A.
    Corrosion Behavior in Acid and Alkaline Media of Nickel Coatings Deposited at Room Temperature2018In: Russian journal of applied chemistry, ISSN 1070-4272, E-ISSN 1608-3296, Vol. 91, no 9, p. 1441-1450Article in journal (Refereed)
    Abstract [en]

    Impedance spectroscopy, chronovoltammetry, chronopotentiometry, scanning electron microscopy, and atomic-force microscopy were used to examine the corrosion behavior in acid and alkaline media and the morphology of nickel coatings electrodeposited from acetate, tartrate, and isobutyrate electrolytes at a temperature of 20–25°C. Models describing the nickel corrosion processes in H2SO4 and NaOH solutions were suggested. It was found that nickel coatings formed from isobutyrate electrolytes have the highest corrosion resistance.

  • 302.
    Makarova, Irina
    et al.
    Belarusian State Technol Univ, Chem Technol & Engn Fac, Dept Chem Technol Electrochem Prod & Elect Engn M, Sverdlova Str 13a, Minsk 220006, BELARUS.;LUT Univ, Sch Engn Sci, Dept Separat & Purificat, Yliopistonkatu 34, FI-53850 Lappeenranta, Finland..
    Dobryden, Illia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Kharitonov, Dmitry
    Belarusian State Technol Univ, Chem Technol & Engn Fac, Dept Chem Technol Electrochem Prod & Elect Engn M, Sverdlova Str 13a, Minsk 220006, BELARUS.;Polish Acad Sci, Jerzy Haber Inst Catalysis & Surface Chem, Niezapominajek 8, PL-30239 Krakow, Poland..
    Kasach, Aliaksandr
    Belarusian State Technol Univ, Chem Technol & Engn Fac, Dept Chem Technol Electrochem Prod & Elect Engn M, Sverdlova Str 13a, Minsk 220006, BELARUS..
    Ryl, Jacek
    Gdansk Univ Technol, Dept Electrochem Corros & Mat Engn, Narutowicza Str 11-12, PL-80233 Gdansk, Poland..
    Repo, Eveliina
    LUT Univ, Sch Engn Sci, Dept Separat & Purificat, Yliopistonkatu 34, FI-53850 Lappeenranta, Finland..
    Vuorinen, Esa
    Lulea Univ Technol, Dept Engn Sci & Math, S-97187 Lulea, Sweden..
    Nickel-nanodiamond coatings electrodeposited from tartrate electrolyte at ambient temperature2019In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 380, article id 125063Article in journal (Refereed)
    Abstract [en]

    In this study, nanocrystalline Ni and Ni-diamond coatings were obtained by electrodeposition from tartrate electrolyte at ambient temperature aiming at improving corrosion and wear properties of the material. The created surfaces were investigated with regard to microhardness, adhesion, wear- and corrosion-resistance. The various methods such as atomic force microscopy, scanning electron microscopy, electrochemical impedance spectroscopy and linear polarization technique were applied to study the coating surface properties. The introduction of nanodiamond particles into the coating led to a rougher surface structure and a bigger grain size in comparison to bare nickel coating. Our study shows that the addition of 5.10(-2) (g dm(-3)) of nanodiamonds to the plating bath is enough to obtain composite coatings with a clear increase in microhardness and wear resistance. The slightly improved corrosion resistance of the coating, decrease in corrosion current density from 0.41 to 0.14 mu A cm(-2) in neutral chloride-containing medium, and nobler values of the corrosion potential were also observed.

  • 303.
    Martinez-Abad, Antonio
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. AlbaNova University Centre.
    Giummarella, Nicola
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Differences in extractability under subcritical water reveal interconnected hemicellulose and lignin recalcitrance in birch hardwoods2018In: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270Article in journal (Refereed)
    Abstract [en]

    Hardwoods constitute an essential renewable resource for the production of platform chemicals and bio-based materials. A method for the sequential extraction of hemicelluloses and lignin from hardwoods is proposed using subcritical water in buffered conditions without prior delignification. This allows the cascade isolation of mannan, xylan and lignin-carbohydrate complexes based on their extractability and recalcitrance in birch lignocellulose. The time evolution of the extraction was monitored in terms of composition, oligomeric mass profiling and sequencing of the hemicelluloses, and molecular structure of the lignin and lignin-carbohydrate complexes (LCCs) by heteronuclear single quantum coherence nuclear magnetic resonance (2D HSQC NMR). The minor mannan and pectin populations are easily extractable at short times (<5 min), whereas the major glucuronoxylan (GX) becomes enriched at moderate extraction times. Longer extraction times results in major hydrolysis exhibiting GX fractions with tighter glucuronation spacing and lignin enrichment. The pattern of acetylation and glucuronation in GX is correlated with extractability and with connectivity with lignin through LCCs. This interconnected molecular heterogeneity of hemicelluloses and lignin has important implications for their supramolecular assembly and therefore determines the recalcitrance of hardwood lignocellulosic biomass.

  • 304.
    Martinez-Abad, Antonio
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. Univ Alicante, Analyt Chem Nutr & Food Sci, Alicante, Spain.
    Jimenez-Quero, Amparo
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Wohlert, Jakob
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Spruce hemicelluloses (galactoglucomannan and arabinoglucuronoxylan): Interplay with cellulose and lignin in softwoods2019In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal (Other academic)
  • 305.
    Martinez-Abad, Antonio
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Quero, Amparo Jimenez
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Berglund, Jennie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Giummarella, Nicola
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Henriksson, Gunnar
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Lindström, Mikael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Wallenberg Wood Sci Ctr, Stockholm, Sweden.;KTH Royal Inst Technol, Fibre & Polymer Technol, Stockholm, Sweden..
    Wohlert, Jakob
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Lawoko, Martin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Influence of the molecular structure of wood hemicelluloses on the recalcitrance of lignocellulosic biomass2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 306.
    Martins, Antonio
    et al.
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden..
    Pfirrmann, Thorsten
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden.;Martin Luther Univ Halle Wittenberg, Inst Physiol Chem, D-06114 Halle, Germany..
    Heessen, Stijn
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden.;Sanofi Aventis Deutschland GmbH, Global Business Dev & Licensing Consumer Healthca, D-65926 Frankfurt, Germany..
    Sundqvist, Gustav
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Bulone, Vincent
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Andreasson, Claes
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden..
    Ljungdahl, Per O.
    Stockholm Univ, Wenner Gren Inst, Dept Mol Biosci, SE-10691 Stockholm, Sweden..
    Ssy5 is a signaling serine protease that exhibits atypical biogenesis and marked S1 specificity2018In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 293, no 22, p. 8362-8378Article in journal (Refereed)
    Abstract [en]

    Ssy5 is a signaling endoprotease that plays a key role in regulating central metabolism, cellular aging, and morphological transitions important for growth and survival of yeast (Saccharomyces cerevisiae) cells. In response to extracellular amino acids, Ssy5 proteolytically activates the transcription factors Stp1 and Stp2, leading to enhanced Ssy1-Ptr3-Ssy5 (SPS) sensor-regulated gene expression. Ssy5 comprises a catalytic (Cat) domain and an extensive regulatory prodomain. Ssy5 is refractory to both broad-spectrum and serine protease-specific inhibitors, confounding its classification as a protease, and no information about Ssy5's cleavage-site preferences and its mechanism of substrate selection is available. Here, using mutational and inhibition experiments, we investigated the biogenesis and catalytic properties of Ssy5 and conclusively show that it is a serine protease. Atypical for the majority of serine proteases, Ssy5's prodomain was obligatorily required in cis during biogenesis for the maturation of the proteolytic activity of the Cat domain. Autolysis and Stp1 and Stp2 cleavage occurred between a cysteine (at the P1 site) and a serine or alanine (at the P1 site) and required residues with short side chains at the P1 site. Substitutions in the Cat domain affecting substrate specificity revealed that residues Phe-634, His-661, and Gly-671 in the S1-binding pocket of this domain are important for Ssy5 catalytic function. This study confirms that the signaling protease Ssy5 is a serine protease and provides a detailed understanding of the biogenesis and intrinsic properties of this key enzyme in yeast.

  • 307. Matveev, V. V.
    et al.
    Markelov, D. A.
    Dvinskikh, Sergey
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Shishkin, A. N.
    Tyutyukin, K. V.
    Penkova, A. V.
    Tatarinova, E. A.
    Ignat'Eva, G. M.
    Milenin, S. A.
    Investigation of Melts of Polybutylcarbosilane Dendrimers by 1H NMR Spectroscopy2017In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, no 1, article id 13710Article in journal (Refereed)
    Abstract [en]

    Melts of polybutylcarbosilane (PBC) dendrimers from third (G3) up to sixth (G6) generations are investigated by 1H NMR spectroscopy in a wide temperature range up to 493 K. At room temperature, NMR spectra of G3-G5 dendrimers exhibit resolved, solution-like spectra ("liquid" phase). In contrast, the spectrum of the G6 dendrimer is characterized by a single unresolved broad line at whole temperature range, which supports the presence of an anomalous phase state of G6 at temperatures higher than glass transition temperature. For the first time, an unexpected transition of G5 dendrimer from a molecular liquid state to an anomalous state/phase upon temperature increase has been detected using NMR data. Specifically, an additional wide background line appears in the G5 spectrum above 473 K, and this line corresponds to a G5 state characterized by restricted molecular mobility, i.e., a state similar to the "anomalous" phase of G6 melt. The fraction of the G5 dendrimers in "anomalous" phase at 493 K is approximately 40%. Analysis of the spectral shapes suggests that changes in the G5 dendrimers are reversible with temperature.

  • 308.
    Mazo, Juan J.
    et al.
    Univ Zaragoza, Dept Fis Mat Condensada, Zaragoza, Spain.;Univ Zaragoza, CSIC, Inst Ciencia Mat Aragon, Zaragoza, Spain..
    Martinez, Pedro J.
    Univ Zaragoza, CSIC, Inst Ciencia Mat Aragon, Zaragoza, Spain.;Univ Zaragoza, Dept Fis Aplicada, Zaragoza, Spain..
    Pedraz, Patricia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Hennig, Jana
    Friedrich Schiller Univ Jena, Otto Schott Inst Mat Res OSIM, Lobdergraben 32, D-07743 Jena, Germany..
    Gnecco, Enrico
    Friedrich Schiller Univ Jena, Otto Schott Inst Mat Res OSIM, Lobdergraben 32, D-07743 Jena, Germany..
    Plowing-Induced Structuring of Compliant Surfaces2019In: Physical Review Letters, ISSN 0031-9007, E-ISSN 1079-7114, Vol. 122, no 25, article id 256101Article in journal (Refereed)
    Abstract [en]

    The structures produced by a sharp tip scraping a compliant surface are modeled in the illustrative case of scan patterns formed by a series of parallel lines. This is made possible by a modified version of the Prandtl model for stick-slip friction, with an interaction energy landscape replicating the morphology of the evolving surface. As a result, a ripple motif emerges with a tilt angle increasing linearly with the distance between the scan lines, except for the region close to the left boundary of the scanned area, where the ripples are oriented at 90 degrees. This region can penetrate considerably to the right, forming a complex branched pattern. These predictions are substantiated by atomic force microscopy nanolithography experiments on polystyrene surfaces at room temperature. A simple and robust theoretical protocol for reproducing early-stage wear processes (potentially going beyond single contacts) is thus made available.

  • 309.
    McCarrick, Sarah
    et al.
    Karolinska Inst, Inst Environm Med, S-17177 Stockholm, Sweden..
    Wei, Zheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Moelijker, Nynke
    Toxys, Leiden, Netherlands..
    Derr, Remco
    Toxys, Leiden, Netherlands..
    Persson, Kjell-Arne
    Swerim AB, Lulea, Sweden..
    Hendriks, Giel
    Toxys, Leiden, Netherlands..
    Odnevall Wallinder, Inger
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Hedberg, Yolanda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Karlsson, Hanna L.
    Karolinska Inst, Inst Environm Med, S-17177 Stockholm, Sweden..
    High variability in toxicity of welding fume nanoparticles from stainless steel in lung cells and reporter cell lines: the role of particle reactivity and solubility2019In: Nanotoxicology, ISSN 1743-5390, E-ISSN 1743-5404Article in journal (Refereed)
    Abstract [en]

    Millions of people in the world perform welding as their primary occupation resulting in exposure to metal-containing nanoparticles in the fumes generated. Even though health effects including airway diseases are well-known, there is currently a lack of studies investigating how different welding set-ups and conditions affect the toxicity of generated nanoparticles of the welding fume. The aim of this study was to investigate the toxicity of nine types of welding fume particles generated via active gas shielded metal arc welding (GMAW) of chromium-containing stainless steel under different conditions and, furthermore, to correlate the toxicity to the particle characteristics. Toxicological endpoints investigated were generation of reactive oxygen species (ROS), cytotoxicity, genotoxicity and activation of ToxTracker reporter cell lines. The results clearly underline that the choice of filler material has a large influence on the toxic potential. Fume particles generated by welding with the tested flux-cored wire (FCW) were found to be more cytotoxic compared to particles generated by welding with solid wire or metal-cored wire (MCW). FCW fume particles were also the most potent in causing ROS and DNA damage and they furthermore activated reporters related to DNA double- strand breaks and p53 signaling. Interestingly, the FCW fume particles were the most soluble in PBS, releasing more chromium in the hexavalent form and manganese compared to the other fumes. These results emphasize the importance of solubility of different metal constituents of the fume particles, rather than the total metal content, for their acute toxic potential.

  • 310.
    McCracken, Joselle M.
    et al.
    Univ Illinois, Dept Chem, 600 S Matthews Ave, Urbana, IL 61801 USA..
    Rauzan, Brittany M.
    Univ Illinois, Dept Chem, 600 S Matthews Ave, Urbana, IL 61801 USA..
    Kjellman, Jacob C. E.
    Univ Illinois, Dept Chem, 600 S Matthews Ave, Urbana, IL 61801 USA..
    Su, Hanxiao
    Univ Illinois, Frederick Seitz Mat Res Lab, 1304 West Green St, Urbana, IL 61801 USA.;Univ Illinois, Dept Mat Sci & Engn, 1304 West Green St, Urbana, IL 61801 USA..
    Rogers, Simon A.
    Univ Illinois, Dept Chem & Biomol Engn, 600 S Matthews Ave, Urbana, IL 61801 USA..
    Nuzzo, Ralph G.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Univ Illinois, Dept Chem, 600 S Matthews Ave, Urbana, IL 61801 USA.;Univ Illinois, Frederick Seitz Mat Res Lab, 1304 West Green St, Urbana, IL 61801 USA.;Univ Illinois, Dept Mat Sci & Engn, 1304 West Green St, Urbana, IL 61801 USA.;KTH Royal Inst Technol, Surface & Corros Sci, Sch Engn Sci Chem Biotechnol & Hlth, Drottning Kristinasvag 51, S-10044 Stockholm, Sweden..
    Ionic Hydrogels with Biomimetic 4D-Printed Mechanical Gradients: Models for Soft-Bodied Aquatic Organisms2019In: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 29, no 28, article id 1806723Article in journal (Refereed)
    Abstract [en]

    Direct-ink writing (DIW), a rapidly growing and advancing form of additive manufacturing, provides capacities for on-demand tailoring of materials to meet specific requirements for final designs. The penultimate challenge faced with the increasing demand of customization is to extend beyond modification of shape to create 4D structures, dynamic 3D structures that can respond to stimuli in the local environment. Patterning material gradients is foundational for assembly of 4D structures, however, there remains a general need for useful materials chemistries to generate gray scale gradients via DIW. Here, presented is a simple materials assembly paradigm using DIW to pattern ionotropic gradients in hydrogels. Using structures that architecturally mimic sea-jelly organisms, the capabilities of spatial patterning are highlighted as exemplified by selectively programming the valency of the ion-binding agents. Spatial gradients, when combined with geometry, allow for programming the flexibility and movement of iron oxide nanoparticle-loaded ionotropic hydrogels to generate 4D-printed structures that actuate in the presence of local magnetic fields. This work highlights approaches to 4D design complexity that exploits 3D-printed gray-scale/gradient mechanics.

  • 311.
    McKee, Lauren S.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Martinez-Abad, Antonio
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Ruthes, Andrea C.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. AlbaNova Univ Ctr, KTH Royal Inst .
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Brumer, Harry
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Focused Metabolism of beta-Glucans by the Soil Bacteroidetes Species Chitinophaga pinensis2019In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 85, no 2, article id UNSP e02231-18Article in journal (Refereed)
    Abstract [en]

    The genome and natural habitat of Chitinophaga pinensis suggest it has the ability to degrade a wide variety of carbohydrate-based biomass. Complementing our earlier investigations into the hydrolysis of some plant polysaccharides, we now show that C. pinensis can grow directly on spruce wood and on the fungal fruiting body. Growth was stronger on fungal material, although secreted enzyme activity was high in both cases, and all biomass-induced secretomes showed a predominance of beta-glucanase activities. We therefore conducted a screen for growth on and hydrolysis of beta-glucans isolated from different sources. Most noncrystalline beta-glucans supported good growth, with variable efficiencies of polysaccharide deconstruction and oligosaccharide uptake, depending on the polysaccharide backbone linkage. In all cases, beta-glucan was the only type of polysaccharide that was effectively hydrolyzed by secreted enzymes. This contrasts with the secretion of enzymes with a broad range of activities observed during growth on complex heteroglycans. Our findings imply a role for C. pinensis in the turnover of multiple types of biomass and suggest that the species may have two metabolic modes: a "scavenging mode," where multiple different types of glycan may be degraded, and a more "focused mode" of beta-glucan metabolism. The significant accumulation of some types of beta-gluco-oligosaccharides in growth media may be due to the lack of an appropriate transport mechanism, and we propose that this is due to the specificity of expressed polysaccharide utilization loci. We present a hypothetical model for beta-glucan metabolism by C. pinensis that suggests the potential for nutrient sharing among the microbial litter community. IMPORTANCE It is well known that the forest litter layer is inhabited by a complex microbial community of bacteria and fungi. However, while the importance of fungi in the turnover of natural biomass is well established, the role of their bacterial counterparts is less extensively studied. We show that Chitinophaga pinensis, a prominent member of an important bacterial genus, is capable of using both plant and fungal biomass as a nutrient source but is particularly effective at deconstructing dead fungal material. The turnover of dead fungus is key in natural elemental cycles in the forest. We show that C. pinensis can perform extensive degradation of this material to support its own growth while also releasing sugars that may serve as nutrients for other microbial species. Our work adds detail to an increasingly complex picture of life among the environmental microbiota.

  • 312.
    Mei, Nanxuan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Hedberg, Jonas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Odnevall Wallinder, Inger
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Blomberg, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Division Bioscience and Materials, RISE Research Institutes of Sweden, Stockholm, 111 21, Sweden.
    Influence of Biocorona Formation on the Transformation and Dissolution of Cobalt Nanoparticles under Physiological Conditions2019In: ACS Omega, ISSN 2470-1343, Vol. 4, no 26, p. 21778-21791Article in journal (Refereed)
    Abstract [en]

    Cobalt (Co) nanoparticles (NPs) are produced in different applications and unintentionally generated at several occupational and traffic settings. Their diffuse dispersion may lead to interactions with humans and aquatic organisms via different exposure routes that include their transformation/dissolution in biological media. This paper has investigated the particle stability and reactivity of Co NPs (dispersed by sonication prior to exposure) interacting with selected individual biomolecules (amino acids, polypeptides, and proteins) in phosphate-buffered saline (PBS). No or minor adsorption of amino acids (glutamine, glutamic acid, lysine, and cysteine) was observed on the Co NPs, independent of the functional group and charge. Instead, phosphate adsorption resulted in the formation of a surface layer (a corona) of Co phosphate. The adsorption of larger biomolecules (polyglutamic acid, polylysine, lysozyme, and mucin) was evident in parallel with the formation of Co phosphate. The dissolution of the Co NPs was rapid as 35-55% of the particle mass was dissolved within the first hour of exposure. The larger biomolecules suppressed the dissolution initially compared to exposure in PBS only, whereas the dissolution was essentially unaffected by the presence of amino acids, with cysteine as an exception. The formation of Co phosphate on the NP surface reduced the protective properties of the surface oxide of the Co NPs, as seen from the increased levels of the released Co when compared with the nonphosphate-containing saline. The results underline the diversity of possible outcomes with respect to surface characteristics and dissolution of Co NPs in biological media and emphasize the importance of surface interactions with phosphate on the NP characteristics and reactivity.

  • 313.
    Meng, Qijun
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Zhang, Biaobiao
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Fan, Lizhou
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Liu, H.
    Valvo, M.
    Edström, K.
    Cuartero, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    de Marco, R.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Efficient BiVO4 Photoanodes by Postsynthetic Treatment: Remarkable Improvements in Photoelectrochemical Performance from Facile Borate Modification2019In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 58, no 52, p. 19027-19033Article in journal (Refereed)
    Abstract [en]

    Water-splitting photoanodes based on semiconductor materials typically require a dopant in the structure and co-catalysts on the surface to overcome the problems of charge recombination and high catalytic barrier. Unlike these conventional strategies, a simple treatment is reported that involves soaking a sample of pristine BiVO4 in a borate buffer solution. This modifies the catalytic local environment of BiVO4 by the introduction of a borate moiety at the molecular level. The self-anchored borate plays the role of a passivator in reducing the surface charge recombination as well as that of a ligand in modifying the catalytic site to facilitate faster water oxidation. The modified BiVO4 photoanode, without typical doping or catalyst modification, achieved a photocurrent density of 3.5 mA cm−2 at 1.23 V and a cathodically shifted onset potential of 250 mV. This work provides an extremely simple method to improve the intrinsic photoelectrochemical performance of BiVO4 photoanodes.

  • 314.
    Menzel, Carolin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Gonzalez-Martinez, Chelo
    Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Chiralt, Amparo
    Univ Politecn Valencia, Inst Ingn Alimentos Desarrolla, Dept Tecnol Alimentos, Valencia, Spain..
    Vilaplana, Francisco
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Antioxidant starch films containing sunflower hull extracts2019In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 214, p. 142-151Article in journal (Refereed)
    Abstract [en]

    This study explores the preparation of antioxidant starch food packaging materials by the incorporation of valuable phenolic compounds extracted from sunflower hulls, which are an abundant by-product from food industry. The phenolic compounds were extracted with aqueous methanol and embedded into starch films. Their effect on starch films was investigated in terms of antioxidant activity, optical, thermal, mechanical, barrier properties and changes in starch molecular structure. The starch molecular structure was affected during thermal processing resulting in a decrease in molar mass, smaller amylopectin molecules and shorter amylose branches. Already 1-2% of extracts were sufficient to produce starch films with high antioxidant capacity. Higher amounts (4-6%) of extract showed the highest antioxidant activity, the lowest oxygen permeability and high stiffness and poor extensibility. The phenolic extracts affected predominantly the mechanical properties, whereas other changes could mainly be correlated to the lower glycerol content which was partially substituted by the extract.

  • 315.
    Meyer, Gerd
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Small cause - Great effect: What the 4f(n+1)5d(0) -> 4f(n)5d(1) configuration crossover does to the chemistry of divalent rare-earth halides and coordination compounds2019In: Journal of Solid State Chemistry, ISSN 0022-4596, E-ISSN 1095-726X, Vol. 270, p. 324-334Article in journal (Refereed)
    Abstract [en]

    The rare-earth elements in the divalent state, i.e. with oxidation number + 2, may either have the electron configuration 4f(n+1)5d degrees(symbolized as R2+) or 4f(n)5d(1) (R(3+)e(-)). As R2+ (R = Eu, Yb, Sm, Tm, Dy, Nd) they can either be contained in extended solids as in the insulating diiodides RI2, or in coordination complexes such as samarocene, Kagan's reagent, or TmI2(DME)(3). In the case of R(3+)e(-), the "excess" d electron can either be delocalized and cause (semi)metallic behavior in extended solids, e.g. in LaI2, or localized with the R(3+)e(-) = 4f(n)5d(1) ion trapped in a coordination complex with (super)bulky ligands such as in [K(2.2.2-crypt)][LaCp ''(3)]. Thus, the seemingly small cause of a one-electron configuration crossover, 4f(n+1)5d degrees <--> Hf(n)5d(1) has a large effect on the chemical behavior and physical properties of the respective compounds where atomic properties and ligand effects play important roles.

  • 316.
    Mikkonen, Saara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. Univ Bern, Inst Infect Dis, Clin Pharmacol Lab, Bern, Switzerland..
    Caslayskal, Jitka
    Univ Bern, Inst Infect Dis, Clin Pharmacol Lab, Bern, Switzerland..
    Gebauer, Petr
    Czech Acad Sci, Inst Analyt Chem, Brno, Czech Republic..
    Thormanni, Wolfgang
    Univ Bern, Inst Infect Dis, Clin Pharmacol Lab, Bern, Switzerland..
    Inverse cationic ITP for separation of methadone enantiomers with sulfated beta-cyclodextrin as chiral selector2019In: Electrophoresis, ISSN 0173-0835, E-ISSN 1522-2683, Vol. 40, no 5, p. 659-667Article in journal (Refereed)
    Abstract [en]

    Chiral ITP of the weak base methadone using inverse cationic configurations with H+ as leading component and multiple isomer sulfated beta-CD (S-beta-CD) as leading electrolyte (LE) additive, has been studied utilizing dynamic computer simulation, a calculation model based on steady-state values of the ITP zones, and capillary ITP. By varying the amount of acidic S-beta-CD in the LE composed of 3-morpholino-2-hydroxypropanesulfonic acid and the chiral selector, and employing glycylglycine as terminating electrolyte (TE), inverse cationic ITP provides systems in which either both enantiomers, only the enantiomer with weaker complexation, or none of the two enantiomers form cationic ITP zones. For the configuration studied, the data reveal that only S-methadone migrates isotachophoretically when the S-beta-CD concentration in the LE is between about 0.484 and 1.113 mM. Under these conditions, R-methadone migrates zone electrophoretically in the TE. An S-beta-CD concentration between about 0.070 and 0.484 mM results in both S- and R-methadone forming ITP zones. With >1.113 mM and < about 0.050 mM of S-beta-CD in the LE both enantiomers are migrating within the TE and LE, respectively. Chiral inverse cationic ITP with acidic S-beta-CD in the LE is demonstrated to permit selective ITP trapping and concentration of the less interacting enantiomer of a weak base.

  • 317. Mittal, P.
    et al.
    Prasoodanan Pk, V.
    Dhakan, D. B.
    Kumar, Sanjiv
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. Metagenomics and Systems Biology Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh, India.
    Sharma, V. K.
    Metagenome of a polluted river reveals a reservoir of metabolic and antibiotic resistance genes2019In: Environmental Microbiomes, ISSN 2524-6372, Vol. 14, no 1, article id 5Article in journal (Refereed)
    Abstract [en]

    Background: Yamuna, a major tributary of Ganga, which flows through the national capital region of Delhi, is among the major polluted rivers in India. The accumulation of various effluents, toxic chemicals, heavy metals, and increased organic load in the Yamuna directly affects the organisms that thrive inside or around this river. It also makes it an ideal site for studying the impact of pollution on the river microflora, which are sentinels of the water quality. Results: In this study, the microbial community structure and functional diversity of the Yamuna river water was assessed from the New Delhi region. The community structure of Yamuna during pre-monsoon (June) was found to be significantly different from the post-monsoon (November) time, with Acinetobacter being the most abundant genus during June, and Aeromonas during November. The functional characterization revealed the higher abundance of Methyl-accepting chemotaxis protein in the river water, which could be important for the microbial chemosensory adaptation in the environment. A higher abundance of genes related to nitrogen and sulfur metabolism, metal tolerance, and xenobiotic degradation, and complete degradation pathways of aromatic compounds such as toluene, xylene, benzene and phenol were identified. Further, the results showed the presence of a pool of antibiotic resistance genes in the bacterial microbiome in the Yamuna alongside a large number of broad-spectrum antibiotics, such as carbapenemases and metallo-β-lactamases. Efflux mechanism of resistance was found to dominate among these microbes conferring multi-drug resistance. The Principal Coordinate Analysis of the taxonomic composition of the Yamuna River water with publicly available freshwater and sewage datasets revealed significant differences in the two Yamuna samples and a greater resemblance of pre-monsoon Yamuna sample to sewage sample owing to the higher pollution levels in Yamuna in the pre-monsoon time. Conclusion: The metagenomic study of the Yamuna river provides the first insights on the bacterial microbiome composition of this large polluted river, and also helps to understand the dynamics in the community structure and functions due to seasonal variations. The presence of antibiotic resistance genes and functional insights on the metabolic potential of a polluted river microbiome are likely to have several applications in health, biotechnology and bioremediation.

  • 318.
    Mozuraitis, Raimondas
    et al.
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden.;Nat Res Ctr, Inst Ecol, Lab Chem & Behav Ecol, Akad 2, LT-08412 Vilnius, Lithuania..
    Murtazina, Rushana
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Zurita, Javier
    Stockholm Univ, Dept Environm Sci & Analyt Chem, SE-10691 Stockholm, Sweden..
    Pei, Yuxin
    Northwest A&F Univ, Dept Appl Chem, Yangling 712100, Shaanxi, Peoples R China..
    Ilag, Leopold
    Stockholm Univ, Dept Environm Sci & Analyt Chem, SE-10691 Stockholm, Sweden..
    Wiklund, Christer
    Stockholm Univ, Dept Zool, SE-10691 Stockholm, Sweden..
    Borg-Karlson, Anna-Karin
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry. Tartu Univ, Div Organ Chem, Inst Technol, EE-50411 Tartu, Estonia..
    Anti-aphrodisiac pheromone, a renewable signal in adult butterflies2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 14262Article in journal (Refereed)
    Abstract [en]

    The male butterfly Pieris napi produces the anti-aphrodisiac pheromone methyl salicylate (MeS) and transfers it to the female during mating. After mating she releases MeS, when courted by conspecific males, which decreases her attractiveness and the duration of male harassment, thus increasing her time available for egg-laying. In previous studies we have shown that males produced MeS from the amino acid L-phenylalanine (L-Phe) acquired during larval stage. In this study we show that adult males of P. napi can utilize L-Phe and aromatic flower volatiles as building blocks for production of anti-aphrodisiac pheromone and transfer it to females during mating. We demonstrate this by feeding butterflies with stable isotope labelled molecules mixed in sugar solutions, and, to mimic the natural conditions, we fed male butterflies with floral nectar of Bunias orientalis plants treated with labelled L-Phe. The volatiles from butterflies and plants were collected and identified by solid phase micro extraction, gas chromatography and mass spectrometry techniques. Since P. napi is polygamous, males would gain from restoring the titre of MeS after mating and the use of aromatic precursors for production of MeS could be considered as an advantageous trait which could enable butterflies to relocate L-Phe for other needs.

  • 319.
    Mueller, Katharina
    et al.
    Helmholtz Zentrum Dresden Rossendorf, Inst Resource Ecol, Bautzner Landstr 400, D-01328 Dresden, Germany..
    Szabo, Zoltan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Zhang, Xiaobin
    Univ Manitoba, Dept Chem, 144 Dysart Rd, Winnipeg, MB R3T 2N2, Canada..
    Interdisciplinary Round-Robin Test on Molecular Spectroscopy of the U(VI) Acetate System2019In: ACS Omega, ISSN 2470-1343, Vol. 4, no 5, p. 8167-8177Article in journal (Refereed)
    Abstract [en]

    A comprehensive molecular analysis of a simple aqueous complexing system. U(VI) acetate. selected to be independently investigated by various spectroscopic (vibrational, luminescence, X-ray absorption, and nuclear magnetic resonance spectroscopy) and quantum chemical methods was achieved by an international round-robin test (RRT). Twenty laboratories from six different countries with a focus on actinide or geochemical research participated and contributed to this scientific endeavor. The outcomes of this RRT were considered on two levels of complexity: first, within each technical discipline, conformities as well as discrepancies of the results and their sources were evaluated. The raw data from the different experimental approaches were found to be generally consistent. In particular, for complex setups such as accelerator-based X-ray absorption spectroscopy, the agreement between the raw data was high. By contrast, luminescence spectroscopic data turned out to be strongly related to the chosen acquisition parameters. Second, the potentials and limitations of coupling various spectroscopic and theoretical approaches for the comprehensive study of actinide molecular complexes were assessed. Previous spectroscopic data from the literature were revised and the benchmark data on the U(VI) acetate system provided an unambiguous molecular interpretation based on the correlation of spectroscopic and theoretical results. The multimethodologic approach and the conclusions drawn address not only important aspects of actinide spectroscopy but particularly general aspects of modern molecular analytical chemistry.

  • 320.
    Mushi, Ngesa Ezekiel
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. Department of Mechanical and Industrial Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar es Salaam, Tanzania.
    Nishino, Takashi
    Kobe Univ, Dept Chem Sci & Engn, Kobe, Hyogo 6578501, Japan..
    Berglund, Lars A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Strong and Tough Chitin Film from alpha-Chitin Nanofibers Prepared by High Pressure Homogenization and Chitosan Addition2019In: ACS Sustainable Chemistry and Engineering, ISSN 2168-0485, Vol. 7, no 1, p. 1692-1697Article in journal (Refereed)
    Abstract [en]

    Chitin nanofibers are an interesting biological nanomaterial for advanced applications, for example, in medicine, electronics, packaging and water purification. The challenge is to separate chitin nanofibers from protein in the exoskeleton structure of arthropods and avoid nanofibril aggregation to realize the mechanical potential of chitin. In this work, we developed a new method for the preparation of chitin nanofibers from lobster shell exoskeleton using 10 wt % chitosan as a sacrificial polymer. The addition of chitosan in the raw chitin colloidal suspension during high pressure homogenization process at pH 3 significantly reduced the agglomeration of chitin nanofibers as revealed by dynamic light scattering and transmission electron microscopy. Chitin film prepared from the chitin nanofiber suspension by vacuum filtration exhibited a true nanofibrils network structure without fibril aggregations as characterized by scanning electron microscopy. The presence of chitosan not only improves the colloidal stability of chitin nanofibers suspension but also facilitates the formation of chitin nanofiber network structure in the film as indicated by wide-angle X-ray diffraction analysis. The chitin nanofiber film with 4 +/- 1 wt % residual chitosan showed high tensile strength (187.2 +/- 5.6 MPa) and high work of fracture (12.1 +/- 0.4 MJ/m(3)), much higher than those chitin and chitosan films reported previously in the literature.

  • 321. Nadiv, R.
    et al.
    Fernandes, Ricardo M. F.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Ochbaum, G.
    Dai, Jing
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Buzaglo, M.
    Varenik, M.
    Biton, R.
    Furo, Istvan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Regev, O.
    Polymer nanocomposites: Insights on rheology, percolation and molecular mobility2018In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 153, p. 52-60Article in journal (Refereed)
    Abstract [en]

    The integration of carbon nanotubes (CNTs) into a polymer matrix strongly affects the rheological behavior that in turn may hamper the overall performance of the resulting composite. Research in this topic has focused on bulk rheological properties, while here we employ NMR diffusion experiments to explore the mobility (diffusivity) of epoxy molecules when loaded with CNTs. Rheology and light microscopy indicate percolation of CNT aggregates. Those aggregates cage a substantial amount of epoxy molecules while small angle X-ray scattering indicates some rearrangement of epoxy molecules in the vicinity of the nanotubes. NMR diffusion experiments distinguish between the slow diffusion of the caged molecules and that of the free ones, and relate the fraction of the former to the macroscopic system viscosity. The demonstrated surface-induced slowing-down of diffusion is attributed to strong intermolecular π-π interactions among the epoxy molecules, and between them and the CNT surface. These findings demonstrate the utility of NMR diffusion experiments as an additional method applied to nanocomposites. 

  • 322.
    Natarajan Arul, Murugan
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
    Nordberg, Agneta
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Centres, Albanova VinnExcellence Center for Protein Technology, ProNova. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Different Positron Emission Tomography Tau Tracers Bind to Multiple Binding Sites on the Tau Fibril: Insight from Computational Modeling2018In: ACS Chemical Neuroscience, ISSN 1948-7193, E-ISSN 1948-7193, Vol. 9, no 7, p. 1757-1767Article in journal (Refereed)
    Abstract [en]

    Using the recently reported cryo-EM structure for the tau fibril [Fitzpatrick et al. (2017) Nature 547, 185-190], which is a potential target concerning Alzheimer's disease, we present the first molecular modeling studies on its interaction with various positron emission tomography (PET) tracers. Experimentally, based on the binding assay studies, at least three different high affinity binding sites have been reported for tracers in the tau fibril. Herein, through integrated modeling using molecular docking, molecular dynamics, and binding free energy calculations, we provide insight into the binding patterns of various tracers to the tau fibril. We suggest that there are four different high affinity binding sites available for many of the studied tracers showing varying binding affinity to different binding sites. Thus, PBB3 binds most strongly to site 4, and interestingly, this site is not a preferable site for any other tracers. For THIC5351, our data show that it strongly binds to sites 3 and 1, the former one being more preferable. We also find that MK6240 and T807 bind to site 1 specifically. The modeling data also give some insight into whether a tracer bound to a specific site can be replaced by others or not. For example, the displacement of T807 by PBB3 as reported experimentally can also be explained and attributed to the larger binding affinity of the latter compound in all binding sites. The binding free energy results explain very well the small binding affinity of THK523 compared to all the aryl quinoline moieties containing THK tracers. The ability of certain tau tracers, like FDDNP and THK523, to bind to amyloid fibrils has also been investigated. Furthermore, such off-target interaction of tau tracers with amyloid beta fibrils has been validated using a quantum mechanical fragmentation approach.

  • 323. Nelson, A. Z.
    et al.
    Schweizer, K. S.
    Rauzan, B. M.
    Nuzzo, Ralph G.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States.
    Vermant, J.
    Ewoldt, R. H.
    Designing and transforming yield-stress fluids2019In: Current opinion in solid state & materials science, ISSN 1359-0286, E-ISSN 1879-0348, Vol. 23, no 5, article id 100758Article, review/survey (Refereed)
    Abstract [en]

    We review progress in designing and transforming multi-functional yield-stress fluids and give a perspective on the current state of knowledge that supports each step in the design process. We focus mainly on the rheological properties that make yield-stress fluids so useful and the trade-offs which need to be considered when working with these materials. Thinking in terms of “design with” and “design of” yield-stress fluids motivates how we can organize our scientific understanding of this field. “Design with” involves identification of rheological property requirements independent of the chemical formulation, e.g. for 3D direct-write printing which needs to accommodate a wide range of chemistry and material structures. “Design of” includes microstructural considerations: conceptual models relating formulation to properties, quantitative models of formulation-structure-property relations, and chemical transformation strategies for converting effective yield-stress fluids to be more useful solid engineering materials. Future research directions are suggested at the intersection of chemistry, soft-matter physics, and material science in the context of our desire to design useful rheologically-complex functional materials.

  • 324.
    Neranon, Kitjanit
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Alberch, Laura
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Royal Inst Technol, Dept Chem, Teknikringen 36, S-10044 Stockholm, Sweden..
    Ramström, Olof
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Design, Synthesis and Self-Assembly of Functional Amphiphilic Metallodendrimers2020In: ChemistryOpen, ISSN 2191-1363, Vol. 9, no 1, p. 45-52Article in journal (Refereed)
    Abstract [en]

    A new family of alkynylated, amphiphilic dendrimers consisting of amidoamine linkers connected to 5,5 '-functionalized 2,2 '-bipyridine cores has been developed and evaluated in the formation of metallodendrimers of different generations and in self-assembly protocols. A convergent synthetic strategy was applied to provide dumbbell-shaped amphiphilic dendrimers, where the 2,2 '-bipyridine cores could be coordinated to Fe-II centers to afford corresponding metallodendrimers. The ability of the metallic- and non-metallic dendritic structures to self-assemble into functional supramolecular aggregates were furthermore evaluated in aqueous solution. Spherical aggregates with sizes of a few hundred nanometers were generally produced, where controlled disassembly of the metallodendrimers through decomplexation could be achieved.

  • 325.
    Ni, Shengjun
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Carbocation Catalysis for Organic Synthesis2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The most common view of carbocations in organic chemistry is that they are short-lived intermediates in several fundamental reactions, e.g. the classic SN1-reaction. However, carbocations that can delocalize their positive charge can be stable enough to be isolated and used as Lewis acid catalysts, phase transfer catalysts or oxidants in various reactions. The theme of this thesis concerns applying trityl cations as Lewis acid catalysts in different organic reactions. The first chapter presents a general introduction of the field of Lewis acids, the characteristics and applications of carbocations in different organic reactions, and the aims of this thesis. The second chapter describes the carbocation-catalyzed asymmetric Diels–Alder reactions assisted by chiral counteranions. The third chapter shows that carbocations can be utilized as catalysts in oxa-Diels–Alder reactions with unactivated aldehydes and dienes as substrates. The fourth chapter investigates the application of carbocation catalysis in bromination reactions for selective functionalization at the benzylic position and on the aromatic ring, respectively. The fifth chapter highlights that carbocation-catalyzed aldehyde–olefin metathesis reactions can be achieved in high yields by suppressing the decomposition of both starting materials and products.

  • 326.
    Ni, Shengjun
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Abd El Aleem Ali Ali El Remaily, Mahmoud
    Franzén, Johan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Carbocation Catalyzed Bromination of Alkyl Arenes, a Chemoselective sp3 vs. sp2 C−H Functionalization2018In: Advanced Synthesis and Catalysis, ISSN 1615-4150, E-ISSN 1615-4169, Vol. 360, no 21, p. 4197-4204Article in journal (Refereed)
    Abstract [en]

    The versatility of the trityl cation (TrBF4) as a highly efficient Lewis acid organocatalyst isdemonstrated in a light induced benzylic brominaion of alkyl-arenes under mild conditions. The reaction wasconducted at ambient temperature under common hood light (55 W fluorescent light) with catalyst loadingsdown to 2.0 mol% using N-bromosuccinimide (NBS) as the brominating agent. The protocol is applicable toan extensive number of substrates to give benzyl bromides in good to excellent yields. In contrast to mostpreviously reported strategies, this protocol does not require any radical initiator or extensive heating. Forelectron-rich alkyl-arenes, the trityl ion catalyzed bromination could be easily switched between benzylic sp3CH functionalization and arene sp2 CH functionalization by simply alternating the solvent. Thischemoselective switch allows for high substrate control and easy preparation of benzyl bromides andbromoarenes, respectively. The chemoselective switch was also applied in a one-pot reaction of 1-methylnaphthalene for direct introduction of both sp3 CBr and sp2 CBr functionality.

  • 327.
    Ni, Shengjun
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Franzén, Johan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Carbocation catalysed ring closing aldehyde-olefin metathesis2018In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 54, no 92, p. 12982-12985Article in journal (Refereed)
    Abstract [en]

    A highly efficient aldehyde-olefin metathesis catalysed by the carbocation, 4-phenylphenyl-diphenylmethylium ion, has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.

  • 328.
    Ni, Shengjun
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Franzén, Johan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Carbocation Catalyzed Ring Closing Aldehyde-Olefin MetathesisManuscript (preprint) (Other academic)
    Abstract [en]

    A highly efficient aldehyde-olefin metathesis catalyzed by the carbocation, 4-phenylphenyl-diphenylmethylium ion has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.

  • 329. Ni, Wenjun
    et al.
    Gurzadyan, Gagik G.
    Zhao, Jianzhang
    Che, Yuanyuan
    Li, Xiaoxin
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Organic chemistry.
    Singlet Fission from Upper Excited Electronic States of Cofacial Perylene Dimer2019In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, no 10, p. 2428-2433Article in journal (Refereed)
    Abstract [en]

    Singlet fission directly from the upper excited vibrational and electronic states of cofacial perylene dimers, bypassing the relaxed state S-1, was detected within 50 fs. This process competes well with vibrational cooling in S-1 (4.7-7.0 ps) and S-2 -> S-1 internal conversion (380 fs). The singlet fission has the energy threshold E = 3.06 eV. Other competitive relaxation processes are excimer and dimer cation formation on an ultrafast time scale. Excitation to higher energy levels (4.96 eV) leads to a higher efficiency of singlet fission.

  • 330. Niga, P.
    et al.
    Hansson-Mille, P. M.
    Swerin, Agne
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. RISE – Research Institute of Sweden.
    Claesson, Per M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. RISE – Research Institute of Sweden.
    Schoelkopf, J.
    Gane, P. A. C.
    Bergendal, Erik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Tummino, A.
    Campbell, R. A.
    Johnson, C. Magnus
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Interactions between model cell membranes and the neuroactive drug propofol2018In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 526, p. 230-243Article in journal (Refereed)
    Abstract [en]

    Vibrational sum frequency spectroscopy (VSFS) complemented by surface pressure isotherm and neutron reflectometry (NR) experiments were employed to investigate the interactions between propofol, a small amphiphilic molecule that currently is the most common general anaesthetic drug, and phospholipid monolayers. A series of biologically relevant saturated phospholipids of varying chain length from C18 to C14 were spread on either pure water or propofol (2,6-bis(1-methylethyl)phenol) solution in a Langmuir trough, and the change in the molecular structure of the film, induced by the interaction with propofol, was studied with respect to the surface pressure. The results from the surface pressure isotherm experiments revealed that propofol, as long as it remains at the interface, enhances the fluidity of the phospholipid monolayer. The VSF spectra demonstrate that for each phospholipid the amount of propofol in the monolayer region decreases with increasing surface pressure. Such squeeze out is in contrast to the enhanced interactions that can be exhibited by more complex amphiphilic molecules such as peptides. At surface pressures of 22–25 mN m−1, which are relevant for biological cell membranes, most of the propofol has been expelled from the monolayer, especially in the case of the C16 and C18 phospholipids that adopt a liquid condensed phase packing of its alkyl tails. At lower surface pressures of 5 mN m−1, the effect of propofol on the structure of the alkyl tails is enhanced when the phospholipids are present in a liquid expanded phase. Specifically, for the C16 phospholipid, NR data reveal that propofol is located exclusively in the head group region, which is rationalized in the context of previous studies. The results imply a non-homogeneous distribution of propofol in the plane of real cell membranes, which is an inference that requires urgent testing and may help to explain why such low concentration of the drug are required to induce general anaesthesia.

  • 331.
    Niga, Petru
    et al.
    RISE Res Inst Sweden Chem Mat & Surfaces, Box 5607, SE-11486 Stockholm, Sweden..
    Hansson-Mille, Petra M.
    RISE Res Inst Sweden Chem Mat & Surfaces, Box 5607, SE-11486 Stockholm, Sweden..
    Swerin, Agne
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Claesson, Per M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Schoelkopf, Joachim
    Omya Int AG, Baslerstr 42, CH-4665 Oftringen, Switzerland..
    Gane, Patrick A. C.
    Omya Int AG, Baslerstr 42, CH-4665 Oftringen, Switzerland.;Aalto Univ, Sch Chem Technol, Dept Bioprod & Biosyst, FI-00076 Helsinki, Finland..
    Dai, Jing
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Furo, Istvan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Campbell, Richard A.
    Inst Laue Langevin, 71 Ave Martyrs,CS20156, F-38042 Grenoble 9, France.;Univ Manchester, Div Pharm & Optometry, Manchester M13 9PT, Lancs, England..
    Johnson, C. Magnus
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Propofol adsorption at the air/water interface: a combined vibrational sum frequency spectroscopy, nuclear magnetic resonance and neutron reflectometry study2019In: Soft Matter, ISSN 1744-683X, E-ISSN 1744-6848, Vol. 15, no 1, p. 38-46Article in journal (Refereed)
    Abstract [en]

    Propofol is an amphiphilic small molecule that strongly influences the function of cell membranes, yet data regarding interfacial properties of propofol remain scarce. Here we consider propofol adsorption at the air/water interface as elucidated by means of vibrational sum frequency spectroscopy (VSFS), neutron reflectometry (NR), and surface tensiometry. VSFS data show that propofol adsorbed at the air/ water interface interacts with water strongly in terms of hydrogen bonding and weakly in the proximity of the hydrocarbon parts of the molecule. In the concentration range studied there is almost no change in the orientation adopted at the interface. Data from NR show that propofol forms a dense monolayer with a thickness of 8.4 angstrom and a limiting area per molecule of 40 angstrom(2), close to the value extracted from surface tensiometry. The possibility that islands or multilayers of propofol form at the air/water interface is therefore excluded as long as the solubility limit is not exceeded. Additionally, measurements of the 1H NMR chemical shifts demonstrate that propofol does not form dimers or multimers in bulk water up to the solubility limit.

  • 332.
    Nordgren, Niklas
    et al.
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Alvarez-Asencio, Ruben
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. IMDEA Nanosci, Inst Adv Studies, Madrid, Spain..
    Wallqvist, Viveca
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Kjellin, Mikael
    SP Tech Res Inst Sweden, Stockholm, Sweden..
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. SP Tech Res Inst Sweden, Stockholm, Sweden..
    Camacho, Alejandra
    LOreal Res & Innovat, Chicago, IL USA..
    Luengo, Gustavo
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Nanomechanical properties of the stratum corneum and its interaction with a single hair fiber2016In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal (Other academic)
  • 333.
    Nordgren, Niklas
    et al.
    KTH, School of Chemical Science and Engineering (CHE).
    Eklöf, Jens
    KTH, School of Biotechnology (BIO).
    Zhou, Qi
    KTH, Superseded Departments (pre-2005), Biotechnology. AlbaNova Univ Ctr, Royal Inst Technol, Sch Biotechnol, S-10691 Stockholm, Sweden..
    Brumer, Harry
    KTH, School of Biotechnology (BIO).
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    CELL 260-Top-down grafting of xyloglucan to gold monitored by QCM-D and AFM: Enzymatic activity and interactions with cellulose2008In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 235Article in journal (Other academic)
  • 334.
    Nordgren, Niklas
    et al.
    KTH, School of Chemical Science and Engineering (CHE).
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    COLL 468-Nanotribological properties of responsive films: Effect of pH and temperature2008In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 235Article in journal (Other academic)
  • 335.
    Nordgren, Niklas
    et al.
    SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden..
    Skedung, Lisa
    SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden..
    Baghdadli, Nawel
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden.;KTH Royal Inst Technol, Dept Chem, Stockholm, Sweden..
    Luengo, Gustavo
    LOreal Res & Innovat, Aulnay Sous Bois, France..
    Tactile and hair-hair friction behavior of hair fibers2017In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Article in journal (Other academic)
  • 336.
    Nordgren, Niklas
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Stiernstedt, Johanna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Brumer, Harry
    KTH.
    Wågberg, Lars
    KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation. KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Gray, Derek G.
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    CELL 109-Interactions of cellulose surfaces: Friction, adhesion and polysaccharide adsorption2007In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 233, p. 838-838Article in journal (Other academic)
  • 337.
    Norrfors, K. Karin
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Björkbacka, Åsa
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Kessler, Amanda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Wold, Susanna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Jonsson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    γ-radiation induced corrosion of copper in bentonite-water systems under anaerobic conditions2018In: Radiation Physics and Chemistry, ISSN 0969-806X, E-ISSN 1879-0895, Vol. 144, p. 8-12Article in journal (Refereed)
    Abstract [en]

    In this work we have experimentally studied the impact of bentonite clay on the process of radiation-induced copper corrosion in anoxic water. The motivation for this is to further develop our understanding of radiation-driven processes occurring in deep geological repositories for spent nuclear fuel where copper canisters containing the spent nuclear fuel will be embedded in compacted bentonite. Experiments on radiation-induced corrosion in the presence and absence of bentonite were performed along with experiments elucidating the impact irradiation on the Cu2+ adsorption capacity of bentonite. The experiments presented in this work show that the presence of bentonite clay has no or very little effect on the magnitude of radiation-induced corrosion of copper in anoxic aqueous systems. The absence of a protective effect similar to that observed for radiation-induced dissolution of UO2 is attributed to differences in the corrosion mechanism. This provides further support for the previously proposed mechanism where the hydroxyl radical is the key radiolytic oxidant responsible for the corrosion of copper. The radiation effect on the bentonite sorption capacity of Cu2+ (reduced capacity) is in line with what has previously been reported for other cations. The reduced cation sorption capacity is partly attributed to a loss of Al-OH sites upon irradiation.

  • 338.
    Nystrom, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordstrom, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Frenning, Goran
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Peptide loaded microgels as antimicrobial surface coatings2017In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Article in journal (Other academic)
  • 339.
    Nyström, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordström, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Bramhill, Jane
    Univ Manchester, Manchester, Lancs, England..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. IMDEA Nanosci, Inst Adv Studies, Madrid, Spain..
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. SP Tech Res Inst Sweden, SP Chem Mat & Surfaces, Stockholm, Sweden.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden.;Univ Copenhagen, Dept Pharm, Copenhagen, Denmark..
    Peptide-loaded microgels as carriers of antimicrobial peptides2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 340.
    Nyström, Lina
    et al.
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Nordström, Randi
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Strömstedt, Adam
    Uppsala Univ, Dept Med Chem, Uppsala, Sweden..
    Saunders, Brian
    Univ Manchester, Manchester, Lancs, England..
    Alvarez-Asencio, Ruben
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Malmsten, Martin
    Uppsala Univ, Dept Pharm, Uppsala, Sweden..
    Peptide-loaded microgels as antimicrobial surface coatings2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 341.
    Okur, Halil I.
    et al.
    Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    Drexler, Chad I.
    Penn State Univ, Dept Chem, University Pk, PA 16802 USA..
    Tyrode, Eric
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    Cremer, Paul S.
    Penn State Univ, Dept Chem, University Pk, PA 16802 USA.;Penn State Univ, Biochem & Mol Biol, University Pk, PA 16802 USA..
    Roke, Sylvie
    Ecole Polytech Fed Lausanne, Inst Bioengn IBI, Sch Engn STI, Lab Fundamental BioPhoton LBP, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Inst Mat Sci IMX, Sch Engn STI, CH-1015 Lausanne, Switzerland.;Ecole Polytech Fed Lausanne, Lausanne Ctr Ultrafast Sci LACUS, CH-1015 Lausanne, Switzerland..
    The Jones-Ray Effect Is Not Caused by Surface-Active Impurities2018In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 9, no 23, p. 6739-6743Article in journal (Refereed)
    Abstract [en]

    Pure aqueous electrolyte solutions display a minimum in surface tension at concentrations of 2 +/- 1 mM. This effect has been a source of controversy since it was first reported by Jones and Ray in the 1930s. The Jones Ray effect has frequently been dismissed as an artifact linked to the presence of surface-active impurities. Herein we systematically consider the effect of surface-active impurities by purposely adding nanomolar concentrations of surfactants to dilute electrolyte solutions. Trace amounts of surfactant are indeed found to decrease the surface tension and influence the surface chemistry. However, surfactants can be removed by repeated aspiration and stirring cycles, which eventually deplete the surfactant from solution, creating a pristine surface. Upon following this cleaning procedure, a reduction in the surface tension by millimolar concentrations of salt is still observed. Consequently, we demonstrate that the Jones Ray effect is not caused by surface-active impurities.

  • 342. Ou, J.
    et al.
    Xiang, J.
    Liu, J.
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, Dalian University of Technology, Dalian, 116024, China.
    Surface-Supported Metal-Organic Framework Thin-Film-Derived Transparent CoS 1.097 @N-Doped Carbon Film as an Efficient Counter Electrode for Bifacial Dye-Sensitized Solar Cells2019In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, no 16, p. 14862-14870Article in journal (Refereed)
    Abstract [en]

    An effective design for counter electrode (CE) catalytic materials with superior catalytic activity, excellent stability, low cost, and a facile fabrication process is urgently needed for industrialization of dye-sensitized solar cells (DSSCs). Herein, we report a facile in situ method to fabricate transparent CoS 1.097 anchored on an N-doped carbon film electrode through sulfurization of a cobalt-metalloporphyrin metal-organic framework thin film on fluorine-doped tin oxide glass. The transparent film as counter electrode in bifacial DSSCs exhibited higher power conversion efficiency (9.11% and 6.64%), respectively, from front and rear irradiation than that of Pt (8.04% and 5.87%). The uniformly dispersed CoS 1.097 nanoparticles on an N-doped carbon film provide a large catalytic active area and facilitate the electron transfer, which leads to the excellent catalytic ability of the CoS 1.097 @N-doped carbon film. In addition, the in situ preparation of the uniform film with a nanosheet structure offers high electrical conductivity and unobstructed access for the diffusion of triiodide to available electroactive sites, resulting in excellent device performance with superior long-term stability over 1000 h under natural conditions.

  • 343.
    Parrilla, Marc
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Cuartero, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Wearable potentiometric ion sensors2019In: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 110, p. 303-320Article, review/survey (Refereed)
    Abstract [en]

    Wearable potentiometric ion sensors (WPISs) have become an exciting analytical platform that combines chemical, material and electronic efforts to supply physiological information during certain human activities. The real possibility of wearing an analytical device with diverse configurations-sweatband, patches, garments-without disturbing the welfare of the carrier has enabled potentiometric ion sensors both as health quality and sport performance controllers. Recent studies show a large involvement of WPISs in the following of critical biomarkers (timely or continuously), such as sodium, potassium, calcium, magnesium, ammonium and chloride, which are present at relatively high concentrations in sweat (similar to mM levels). Certainly, the non-invasive nature of WPISs and other significant features, e.g., simplicity and cost-effectiveness, have broadened new horizons in relation to applied analytical chemistry. This has been pointed out in the literature over the last decade with the predominance of two analytical outcomes: (i) the improvement of sport performance as a result of continuous detection of ions in sweat (health status of the individual) while decreasing physiological complications (injuries, muscle cramps, fatigue and dehydration) during practice; and (ii) advancements in clinical diagnostics and preventive medicine as a consequence of the monitoring of the health status of patients suffering from any kind of disorder. Beyond the undeniable importance of the integration of WPISs to satisfy current societal needs, the following crucial questions about misleading and missing analytical features need to be answered: To what extent is WPIS technology a reliable analytical tool for the quantification of ions? Is cross-validation the current bottleneck toward further progress? Which are the fundamental steps involving the ion-selective electrode side that would benefit WPIS outcomes? Why is sweat the main (and almost the only) biological fluid to be monitored by WPISs? What is the best sampling strategy to be incorporated into WPIS devices for on-body monitoring of sweat? Which precision limits should be considered to assure a reliable decision-making process? Accordingly, this review focuses on the progression of WPISs from an analytical perspective-merely our vision of the field-within the period between 2010 and 2018. An updated search using specific keywords (wearable, ion, potentiometry, sensor) provided 43 contributions, which are herein highlighted, with a sustainable acceleration over the last three years. Thus, this review describes the current state of WPIS technology, the construction of wearable all-solid-state potentiometric sensors, critical requirements of potentiometric sensors to be fulfilled in a wearable configuration and key features regarding the ideal implementation of WPISs as reliable messengers of physiological information in real scenarios.

  • 344.
    Parrilla, Marc
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Cuartero, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Sanchez, Sara Padrell
    Karolinska Inst, Dept Clin Sci Intervent & Technol, K 57, SE-14186 Stockholm, Sweden.;Karolinska Univ Sjukhuset, Div Obstet & Gynecol, S-14186 Stockholm, Sweden..
    Rajabi, Mina
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Roxhed, Niclas
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Niklaus, Frank
    KTH, School of Electrical Engineering and Computer Science (EECS), Micro and Nanosystems.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Wearable All-Solid-State Potentiometric Microneedle Patch for Intradermal Potassium Detection2019In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, no 2, p. 1578-1586Article in journal (Refereed)
    Abstract [en]

    A new analytical all-solid-state platform for intradermal potentiometric detection of potassium in interstitial fluid is presented here. Solid microneedles are modified with different coatings and polymeric membranes to prepare both the potassium-selective electrode and reference electrode needed for the potentiometric readout. These microneedle-based electrodes are fixed in an epidermal patch suitable for insertion into the skin. The analytical performances observed for the potentiometric cell (Nernstian slope, limit of detection of 10(-4.9) potassium activity, linear range of 10(-4.2) to 10(-1.1), drift of 0.35 +/- 0.28 mV h(-1)), together with a fast response time, adequate selectivity, and excellent reproducibility and repeatability, are appropriate for potassium analysis in interstitial fluid within both clinical and harmful levels. The potentiometric response is maintained after several insertions into animal skin, confirming the resiliency of the microneedle-based sensor. Ex vivo tests based on the intradermal detection of potassium in chicken and porcine skin demonstrate that the microneedle patch is suitable for monitoring potassium changes inside the skin. In addition, the dimensions of the microneedles modified with the corresponding layers necessary to enhance robustness and provide sensing capabilities (1000 mu m length, 45 degrees tip angle, 15 mu m thickness in the tip, and 435 mu m in the base) agree with the required ranges for a painless insertion into the skin. In vitro cytotoxicity experiments showed that the patch can be used for at least 24 h without any side effect for the skin cells. Overall, the developed concept constitutes important progress in the intradermal analysis of ions related to an electrolyte imbalance in humans, which is relevant for the control of certain types of diseases.

  • 345.
    Parrilla, Marc
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Ortiz-Gomez, Inmaculada
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Univ Granada, Fac Sci, Dept Analyt Chem, Campus Fuentenueva, E-18071 Granada, Spain..
    Canovas, Rocio
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Salinas-Castillo, Alfonso
    Univ Granada, Fac Sci, Dept Analyt Chem, Campus Fuentenueva, E-18071 Granada, Spain..
    Cuartero, Maria
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Wearable Potentiometric Ion Patch for On-Body Electrolyte Monitoring in Sweat: Toward a Validation Strategy to Ensure Physiological Relevance2019In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 91, no 13, p. 8644-8651Article in journal (Refereed)
    Abstract [en]

    Herein, the reproducibility and a double validation of on-body measurements provided by new wearable potentiometric ion sensors (WPISs) is presented. Sweat collected during sport practice was first analyzed using the developed device, the pH-meter, and ion chromatography (IC) prior to onbody measurements (off-site validation). Subsequently, the accuracy of onbody measurements accomplished by the WPISs was evaluated by comparison with pH-meter readings and IC after collecting sweat (every 10-12.5 min) during sport practice. The developed device contains sensors for pH, Cl-, K+, and Na+ that are embedded in a flexible sampling cell for sweat analysis. The electrode array was fabricated employing MWCNTs (as an ion-to-electron transducer) and stretchable materials that have been exhaustively characterized in terms of analytical performance, presenting Nernstian slopes within the expected physiological range of each ion analyte (Cl-, 10-100 mM; 10-10 mM; and Na+, 10- 100 mM and pH, 4.5-7.5), drift suitable for midterm exercise practice (0.3 +/- 0.2 mV h(-1)), fast response time, adequate selectivity for sweat measurements, and excellent reversibility. Besides that, the designed sampling cell avoids any sweat contamination and evaporation issues while supplying a passive sweat flow encompassing specifically the individual's perspiration. The interpretation of ion concentration profiles may permit the identification of personal dynamic patterns in sweat composition while practicing sport.

  • 346.
    Paulraj, Thomas
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Crespo, Gaston
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry.
    Svagan, Anna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Cage-like cellulose nanofiber-based microcapsules for electrochemical and biosensor applications2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 256Article in journal (Other academic)
  • 347.
    Paulraj, Thomas
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wennmalm, Stefan
    KTH, School of Engineering Sciences (SCI), Applied Physics, Experimental Biomolecular Physics. KTH, Centres, Science for Life Laboratory, SciLifeLab. ..
    Riazanova, Anastasia, V
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Wu, Qiong
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Crespo, Gaston A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Svagan, Anna J.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Porous Cellulose Nanofiber-Based Microcapsules for Biomolecular Sensing2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 48, p. 41146-41154Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibers (CNFs) have recently attracted a lot of attention in sensing because of their multifunctional character and properties such as renewability, nontoxicity, biodegradability, printability, and optical transparency in addition to unique physicochemical, barrier, and mechanical properties. However, the focus has exclusively been devoted toward developing two-dimensional sensing platforms in the form of nanopaper or nanocellulose-based hydrogels. To improve the flexibility and sensing performance in situ, for example, to detect biomarkers in vivo for early disease diagnostics, more advanced CNF-based structures are needed. Here, we developed porous and hollow, yet robust, CNF-based microcapsules using only the primary plant cell wall components, CNF, pectin, and xyloglucan, to assemble the capsule wall. The fluorescein isothiocyanate-labeled dextrans with M-w of 70 and 2000 kDa could enter the hollow capsules at a rate of 0.13 +/- 0.04 and 0.014 +/- 0.009 s(-1), respectively. This property is very attractive because it minimizes the influence of mass transport through the capsule wall on the response time. As a proof of concept, glucose oxidase (GOx) enzyme was loaded (and cross-linked) in the microcapsule interior with an encapsulation efficiency of 68 +/- 2%. The GOx-loaded microcapsules were immobilized on a variety of surfaces (here, inside a flow channel, on a carbon-coated sensor or a graphite rod) and glucose concentrations up to 10 mM could successfully be measured. The present concept offers new opportunities in the development of simple, more efficient, and disposable nanocellulose-based analytical devices for several sensing applications including environmental monitoring, healthcare, and diagnostics.

  • 348. Peng, T.
    et al.
    Yan, Q.
    Li, Gen
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Zhang, X.
    The Influence of Cu/Fe Ratio on the Tribological Behavior of Brake Friction Materials2018In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 66, no 1, article id 18Article in journal (Refereed)
    Abstract [en]

    Copper and iron are the major ingredients in friction materials, among which Fe often been served as friction reinforcement in the past. But in our recent study, the coefficients of friction (COF) decreased with increasing iron content in composites. In order to study the influence of Cu/Fe ratio on the tribological behavior of the composite under simulative braking conditions, a subscale testing apparatus with the pad-on-disk configuration under various initial braking speeds (IBS) was applied. The changes in mean COFs, wear rates, morphologies and chemical constitutions of friction surface for different composites were investigated. Results showed that the composite containing more Fe content always showed lower mean COF and wear rate, which different from the previous studies. This is because, under severe braking conditions, the tribological behavior of composite mainly depends on the evolution of tribo-oxide film on the surface, not just on the substrate themselves. Higher Fe content accelerated the formation of tribo-oxide film and in turn inhibited the destruction of tribo-oxide film on the surface, which leading to lower mean COF and wear rate, as well as a higher critical IBS for the transition of mean COF and wear rate. This work also provides a way to characterize the fracture strength of tribo-film by carried out a peeling test.

  • 349.
    Petronico, Aaron
    et al.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Moneypenny, Timothy P., II
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA.;Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA..
    Nicolau, Bruno G.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Moore, Jeffrey S.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA.;Univ Illinois, Beckman Inst Adv Sci & Technol, Urbana, IL 61801 USA..
    Nuzzo, Ralph G.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. Univ Illinois, Dept Chem, Urbana, IL 61801 USA.
    Gewirth, Andrew A.
    Univ Illinois, Dept Chem, Urbana, IL 61801 USA..
    Solid-Liquid Lithium Electrolyte Nanocomposites Derived from Porous Molecular Cages2018In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 140, no 24, p. 7504-7509Article in journal (Refereed)
    Abstract [en]

    We demonstrate that solid-liquid nanocomposites derived from porous organic cages are effective lithium ion electrolytes at room temperature. A solid-liquid electrolyte nanocomposite (SLEN) fabricated from a LiTFSI/DME electrolyte system and a porous organic cage exhibits ionic conductivity on the order of 1 x 10(-3) S cm(-1). With an experimentally measured activation barrier of 0.16 eV, this composite is characterized as a superionic conductor. Furthermore, the SLEN displays excellent oxidative stability up to 4.7 V vs Li/Li+. This simple three-component system enables the rational design of electrolytes from tunable discrete molecular architectures.

  • 350.
    Petrou, Georgia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Investigating mucin interactions with diverse surfaces for biomedical applications2019Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mucous membranes are covered with mucus, a viscoelastic hydrogel that plays an essential role in their protection from shear and pathogens. The viscoelasticity of mucus is owing to mucins, a group of densely glycosylated proteins. Mucins can interact with a wide range of surfaces; thus, there is big interest in exploring and manipulating such interactions for biomedical applications. This thesis presents investigations of mucin interactions with hydrophobic surfaces in order to identify the key features of mucin lubricity, as well as describes the development of materials that are optimized to interact with mucins.

     

    In Paper I we investigated the domains which make mucins outstanding boundary lubricants. The results showed that the hydrophobic terminal domains of mucins play a crucial role in the adsorption and lubrication on hydrophobic surfaces. Specifically, protease digestion of porcine gastric mucins and salivary mucins resulted in the cleavage of these domains and the loss of lubricity and surface adsorption. However, a “rescue” strategy was successfully carried out by grafting hydrophobic phenyl groups to the digested mucins and enhancing their lubricity. This strategy also enhanced the lubricity of polymers which are otherwise bad lubricants.

     

    In Paper II we developed mucoadhesive materials based on genetically engineered partial spider silk proteins. The partial spider silk protein 4RepCT was successfully functionalized with six lysines (pLys-4RepCT), or the Human Galectin-3 Carbohydrate Recognition Domain (hGal3-4RepCT). These strategies were aiming to either non-specific electrostatic interactions between the positive lysines and the negative mucins, or specific binding between the hGal3 and the mucin glycans. Coatings, fibers, meshes and foams were prepared from the new silk proteins, and the adsorption of porcine gastric mucins and bovine submaxillary mucins was measured, demonstrating enhanced adsorption.

     

    The work presented demonstrates how mucin-material interactions can provide us with valuable information for the development of new biomaterials. Specifically, mucin-based and mucin-inspired lubricants could provide desired lubrication to a wide range of surfaces, while our new silk based materials could be valuable tools for the development of mucosal dressings.

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