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  • 1. Aili, Daniel
    et al.
    Enander, Karin
    Baltzer, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi.
    Liedberg, Bo
    Assembly of polypeptide-functionalized gold nanoparticles through a heteroassociation- and folding-dependent bridging2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 8, s. 2473-2478Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gold nanoparticles were functionalized with a synthetic polypeptide, de novo-designed to associate with a charge complementary linker polypeptide in a folding-dependent manner. A heterotrimeric complex that folds into two disulphide-linked four-helix bundles is formed when the linker polypeptide associates with two of the immobilized peptides. The heterotrimer forms in between separate particles and induces a rapid and extensive aggregation with a well-defined interpartide spacing. The aggregated particles are redispersed when the disulphide bridge in the linker polypeptide is reduced.

  • 2. Aili, Daniel
    et al.
    Gryko, Piotr
    Sepulveda, Borja
    Dick, John A. G.
    Kirby, Nigel
    Heenan, Richard
    Baltzer, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Liedberg, Bo
    Ryan, Mary P.
    Stevens, Molly M.
    Polypeptide Folding-Mediated Tuning of the Optical and Structural Properties of Gold Nanoparticle Assemblies2011Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 11, nr 12, s. 5564-5573Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Responsive hybrid nanomaterials with well-defined properties are of significant interest for the development of biosensors with additional applications in tissue engineering and drug delivery. Here, we present a detailed characterization using UV-vis spectroscopy and small angle X-ray scattering of a hybrid material comprised of polypeptide-decorated gold nanoparticles with highly controllable assembly properties. The assembly is triggered by a folding-dependent bridging of the particles mediated by the heteroassociation of immobilized helix-loop-helix polypeptides and a complementary nonlinear polypeptide present in solution. The polypeptides are de novo designed to associate and fold into a heterotrimeric complex comprised of two disulfide-linked four-helix bundles. The particles form structured assemblies with a highly defined interparticle gap (4.8 +/- 0.4 nm) that correlates to the size of the folded polypeptides. Transitions in particle aggregation dynamics, mass-fractal dimensions and ordering, as a function of particle size and the concentration of the bridging polypeptide, are observed; these have significant effects on the optical properties of the assemblies. The assembly and ordering of the particles are highly complex processes that are affected by a large number of variables including the number of polypeptides bridging the particles and the particle mobility within the aggregates. A fundamental understanding of these processes is of paramount interest for the development of novel hybrid nanomaterials with tunable structural and optical properties and for the optimization of nanoparticle-based colorimetric biodetection strategies.

  • 3. Berseth, Polly A
    et al.
    Harter, Andrew G
    Zidan, Ragaiy
    Blomqvist, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Araújo, C Moysés
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Scheicher, Ralph H
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Ahuja, Rajeev
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Jena, Puru
    Carbon nanomaterials as catalysts for hydrogen uptake and release in NaAlH42009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 4, s. 1501-1505Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A synergistic approach involving experiment and first-principles theory not only shows that carbon nanostructures can be used as catalysts for hydrogen uptake and release in complex metal hydrides such as sodium alanate, NaAlH(4), but also provides an unambiguous understanding of how the catalysts work. Here we show that the stability of NaAlH(4) originates with the charge transfer from Na to the AlH(4) moiety, resulting in an ionic bond between Na(+) and AlH(4)(-) and a covalent bond between Al and H. Interaction of NaAlH(4) with an electronegative substrate such as carbon fullerene or nanotube affects the ability of Na to donate its charge to AlH(4), consequently weakening the Al-H bond and causing hydrogen to desorb at lower temperatures as well as facilitating the absorption of H(2) to reverse the dehydrogenation reaction. In addition, based on our experimental observations and theoretical calculations it appears the curvature of the carbon nanostructure plays a role in the catalytic process. Ab initio molecular dynamics simulation further reveals the time evolution of the charge transfer process.

  • 4. Bogan, Michael J
    et al.
    Benner, W Henry
    Boutet, Sébastien
    Rohner, Urs
    Frank, Matthias
    Barty, Anton
    Seibert, M Marvin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Maia, Filipe
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Marchesini, Stefano
    Bajt, Sasa
    Woods, Bruce
    Riot, Vincent
    Hau-Riege, Stefan P
    Svenda, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Marklund, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Spiller, Eberhard
    Hajdu, Janos
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Molekylär biofysik.
    Chapman, Henry N
    Single particle X-ray diffractive imaging2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 1, s. 310-6Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In nanotechnology, strategies for the creation and manipulation of nanoparticles in the gas phase are critically important for surface modification and substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified the capability of single-shot imaging of nanoscale objects at suboptical resolutions beyond the radiation-induced damage threshold. By intercepting electrospray-generated particles with a single 15 femtosecond soft-X-ray pulse, we demonstrate diffractive imaging of a nanoscale specimen in free flight for the first time, an important step toward imaging uncrystallized biomolecules.

  • 5.
    Cheah, Seng Kian
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi.
    Perre, Emilie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Rooth, Mårten
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Oorganisk kemi.
    Fondell, Mattis
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Oorganisk kemi.
    Hårsta, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Oorganisk kemi.
    Nyholm, Leif
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Oorganisk kemi.
    Boman, Mats
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Oorganisk kemi.
    Gustafsson, Torbjörn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Lu, Jun
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrostrukturlaboratoriet, MSL.
    Simon, Patrice
    CIRIMAT, Université Paul Sabatier, Toulouse, France.
    Edström, Kristina
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Self-Supported Three-Dimensional Nanoelectrodes for Microbattery Applications2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 9, s. 3230-3233Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A nanostructured three-dimensional (3D) microbattery has been produced and cycled in a Li-ion battery. It consists of a current collector of aluminum nanorods, a uniform layer of 17 nm TiO2 covering the nanorods made using ALD, an electrolyte and metallic lithium counter electrode. The battery is electrochemically cycled more than 50 times. The increase in total capacity is 10 times when using a 3D architechture compared to a 2D system for the same footprint area.

  • 6. Ctistis, G.
    et al.
    Papaioannou, E.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap.
    Patoka, P.
    Gutek, J.
    Fumagalli, P.
    Giersig, M.
    Optical and Magnetic Properties of Hexagonal Arrays of Subwavelength Holes in Optically Thin Cobalt Films2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 1, s. 1-6Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, we present our experimental results on the optical, magnetic, as well as magneto-optic properties of hexagonal arrays of subwavelength holes in optically thin cobalt films. Different meshes were used with hole diameters ranging between 220 and 330 nm while the interhole distance has been kept constant at 470 nm. The hole pattern modifies completely the magnetic behavior of the cobalt films; it gives rise to an increase of the coercive field of the in-plane magnetization with increasing hole diameter and to the appearance of out-of-plane magnetization components. Magneto-optic measurements show a spectacular magneto-optic response at wavelengths where surface plasmon-polaritons are supported by the structure as deduced in optical measurements. The experiments demonstrate the ability to artificially control the magnetic and thus the magneto-optic properties in hole array structures.

  • 7.
    Ding, Feng
    et al.
    Fysiska Institutionen, Göteborgs Universitet.
    Larsson, Peter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap, Materialteori.
    Larsson, J Andreas
    Tyndall National Institute, Unversity College Cork.
    Ahuja, Rajeev
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap, Materialteori.
    Duan, Haiming
    Fysiska Institutionen, Göteborgs Universitet.
    Rosén, Arne
    Fysiska Institutionen, Göteborgs Universitet.
    Bolton, Kim
    University College of Borås.
    The importance of strong carbon-metal adhesion for catalytic nucleation of single-walled carbon nanotubes2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 2, s. 463-468Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Density functional theory is used to show that the adhesion between single-walled carbon nanotubes (SWNTs) and the catalyst particles from which they grow needs to be strong to support nanotube growth. It is found that Fe, Co, and Ni, commonly used to catalyze SWNT growth, have larger adhesion strengths to SWNTs than Cu, Pd, and Au and are therefore likely to be more efficient for supporting growth. The calculations also show that to maintain an open end of the SWNT it is necessary that the SWNT adhesion strength to the metal particle is comparable to the cap formation energy of the SWNT end. This implies that the difference between continued and discontinued SWNT growth to a large extent depends on the carbon-metal binding strength, which we demonstrate by molecular dynamics (MD) simulations. The results highlight that first principles computations are vital for the understanding of the binding strength's role in the SWNT growth mechanism and are needed to get accurate force field parameters for MD.

  • 8.
    Fransson, J
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap.
    Spin Inelastic Electron Tunneling Spectroscopy on Local Spin Adsorbed on Surface2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 6, s. 2414-2417Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The recent experimental conductance measurements taken on magnetic impurities on metallic surfaces, using scanning tunneling microscopy technique and suggesting occurrence of inelastic scattering processes, are theoretically addressed. We argue that the observed conductance signatures are caused by transitions between the spin states that have opened due to, for example, exchange coupling between the local spins and the tunneling electrons, and are directly interpretable in terms of inelastic transitions energies. Feasible measurements using spin-polarized scanning tunneling microscopy that would enable new information about the excitation spectrum of the local spins are discussed.

  • 9.
    Fransson, Jonas
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    King, M. -G
    Yoon, Y.
    Xiao, S.
    Ochiai, Y.
    Reno, J. L.
    Aoki, N.
    Bird, J. P.
    Tuning the Fano Resonance with an Intruder Continuum2014Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 14, nr 2, s. 788-793Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Through a combination of experiment and theory we establish the possibility of achieving strong tuning of Fano resonances (FRs), by allowing their usual two-path geometry to interfere with an additional, "intruder", continuum. As the coupling strength to this intruder is varied, we predict strong modulations of the resonance line shape that, in principle at least, may exceed the amplitude of the original FR itself. For a proof-of-concept demonstration of this phenomenon, we construct a nanoscale interferometer from nonlocally coupled quantum point contacts and utilize the unique features of their density of states to realize the intruder. External control of the intruder coupling is enabled by means of an applied magnetic field, in the presence of which we demonstrate the predicted distortions of the FR. This general scheme for resonant control should be broadly applicable to a Variety of wave-based systems, opening up the possibility of new applications in areas such as chemical and biological sensing and secure communications.

  • 10.
    Fransson, Jonas
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Manoharan, H. C.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Balatsky, A. V.
    Detection and Cloaking of Molecular Objects in Coherent Nanostructures Using Inelastic Electron Tunneling Spectroscopy2010Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 10, nr 5, s. 1600-1604Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We address quantum invisibility in the context of electronics in nanoscale quantum structures. We make use of the freedom of design that quantum corrals provide and show that quantum mechanical objects can be hidden inside the corral, with respect to inelastic electron scattering spectroscopy in combination with scanning tunneling microscopy, and we propose a design strategy. A simple illustration of the invisibility is given in terms of an elliptic quantum corral containing a molecule, with a local vibrational mode, at one of the foci. Our work has implications to quantum information technology and presents new tools for nonlocal quantum detection and distinguishing between different molecules.

  • 11.
    Fu, Le
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Xie, Ling
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Fu, Wenbo
    Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianshan Road 64, Mianyang, Sichuan 621900, People’s Republic of China.
    Hu, Shuanglin
    Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianshan Road 64, Mianyang, Sichuan 621900, People’s Republic of China.
    Zhang, Zhibin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Leifer, Klaus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Engqvist, Håkan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Xia, Wei
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Ultrastrong translucent glass ceramic with nanocrystalline, biomimetic structure2018Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 18, nr 11, s. 7146-7154Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Transparent/translucent glass ceramics (GCs) have broad applications in biomedicine, armor, energy, and constructions. However, GCs with improved optical properties typically suffer from impaired mechanical properties, compared to traditional sintered full-ceramics. We present a method of obtaining high-strength, translucent GCs by preparing ZrO2-SiO2 nanocrystalline glass ceramics (NCGCs), with a microstructure of monocrystalline ZrO2 nanoparticles (NPs), embedded in an amorphous SiO2 matrix. The ZrO2-SiO2 NCGC with a composition of 65%ZrO2-35%SiO2 (molar ratio, 65Zr) achieved an average flexural strength of 1 GPa. This is one of the highest flexural strength values ever reported for GCs. ZrO2 NPs have a core-shell structure, and the shell is a thin (2–3 nm) amorphous Zr/Si interfacial layer that provides strong bonding between the ZrO2 NPs and SiO2 matrix. The diffusion of Si atoms into the ZrO2 NPs forms a Zr-O-Si superlattice. Electron tomography results show that some of the ZrO2 NPs are connected in one direction, forming in situ ZrO2 nanofibers (with length of ~500 nm), and that the ZrO2 nanofibers are stacked in an ordered way in all three dimensions. The nano-architecture of the ZrO2 nanofibers mimics the architecture of mineralized collagen fibril in cortical bone. Strong interface bonding enables efficient load transfer from the SiO2 matrix to the 3D nano-architecture built by ZrO2 nanofibers and NPs, and the 3D nano-architecture carries the majority of the external load. These two factors synergistically contribute to the high strength of the 65Zr NCGC. This study deepens our fundamental understanding of the microstructure-mechanical strength relationship, which could guide the design and manufacture of other high-strength, translucent GCs.

  • 12.
    Gawronski, Heiko
    et al.
    Institute for Solid State Physics, Leibniz University of Hannover.
    Fransson, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Morgenstern, Karina
    Institute for Solid State Physics, Leibniz University of Hannover.
    Real-Space Imaging of Inelastic Friedel-like Surface Oscillations Emerging from Molecular Adsorbates2011Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 11, nr 7, s. 2720-2724Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report real space imaging measurements of inelastic Friedel oscillations. The inelastic electron tunneling spectroscopy, using scanning tunneling microscopy, around dimers of dichlorobenze adsorbates on Au(111) surface display clear spatial modulations that we attribute to inelastic scattering at the molecular sites caused by molecular vibrations. Due to local interactions between the adsorbate and the surface states, the molecular vibrations generate a redistribution of the charge density at energies in a narrow range around the inelastic mode. Our experimental findings are supported by theoretical arguments.

  • 13.
    Hägglund, Carl
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik. Department of Applied Physics, Chalmers University of Technology.
    Apell, Peter S.
    Department of Applied Physics, Chalmers University of Technology.
    Kasemo, Bengt
    Department of Applied Physics, Chalmers University of Technology.
    Maximized optical absorption in ultrathin films and its application to plasmon-based two-dimensional photovoltaics2010Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 10, nr 8, s. 3135-3141Artikkel i tidsskrift (Fagfellevurdert)
  • 14.
    Hägglund, Carl
    et al.
    Department of Applied Physics, Chalmers University of Technology.
    Apell, Peter S.
    Department of Applied Physics, Chalmers University of Technology.
    Kasemo, Bengt
    Department of Applied Physics, Chalmers University of Technology.
    Maximized optical absorption in ultrathin films and its application to plasmon-based two-dimensional photovoltaics (vol 10, pg 3135, 2010)2011Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 11, nr 2, s. 915-916Artikkel i tidsskrift (Fagfellevurdert)
  • 15.
    Hägglund, Carl
    et al.
    Stanford University.
    Zeltzer, G.
    Ruiz, R.
    Thomann, I.
    Lee, H.B.R.
    Brongersma, M.
    Bent, S.
    Self-assembly based plasmonic arrays tuned by atomic layer deposition for extreme visible light absorption2013Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 13, nr 7, s. 3352-3357Artikkel i tidsskrift (Fagfellevurdert)
  • 16.
    Isaksson, Simon
    et al.
    Chalmers, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden..
    Watkins, Erik B.
    Los Alamos Natl Lab, Mat Phys & Applicat Div, MPA 11, Los Alamos, NM 87545 USA..
    Browning, Kathryn L.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Farmaceutiska fakulteten, Institutionen för farmaci.
    Lind, Tania Kjellerup
    Malmo Univ, Dept Biomed Sci, SE-20500 Malmo, Sweden.;Malmo Univ, Biofilm Res Ctr Biointerfaces Hlth & Soc, SE-20500 Malmo, Sweden..
    Cardenas, Marite
    Malmo Univ, Dept Biomed Sci, SE-20500 Malmo, Sweden.;Malmo Univ, Biofilm Res Ctr Biointerfaces Hlth & Soc, SE-20500 Malmo, Sweden..
    Hedfalk, Kristina
    Univ Gothenburg, Dept Chem & Mol Biol, SE-40530 Gothenburg, Sweden..
    Hook, Fredrik
    Chalmers, Dept Appl Phys, SE-41296 Gothenburg, Sweden..
    Andersson, Martin
    Chalmers, Dept Chem & Chem Engn, SE-41296 Gothenburg, Sweden..
    Protein-Containing Lipid Bilayers Intercalated with Size-Matched Mesoporous Silica Thin Films2017Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 17, nr 1, s. 476-485Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Proteins are key components in a multitude of biological processes, of which the functions carried out by transmembrane (membrane-spanning) proteins are especially demanding for investigations. This is because this class of protein needs to be incorporated into a lipid bilayer representing its native environment, and in addition, many experimental conditions also require a solid support for stabilization and analytical purposes. The solid support substrate may, however, limit the protein functionality due to protein material interactions and a lack of physical space. We have in this work tailored the pore size and pore ordering of a mesoporous silica thin film to match the native cell-membrane arrangement of the transmembrane protein human aquaporin 4 (hAQP4). Using neutron reflectivity (NR), we provide evidence of how substrate pores host the bulky water-soluble domain of hAQP4, which is shown to extend 7.2 nm into the pores of the substrate. Complementary surface analytical tools, including quartz crystal microbalance with dissipation monitoring (QCM-D) and fluorescence microscopy, revealed successful protein-containing supported lipid bilayer (pSLB) formation on mesoporous silica substrates, whereas pSLB formation was hampered on nonporous silica. Additionally, electron microscopy (TEM and SEM), light scattering (DLS and stopped-flow), and small-angle X-ray scattering (SAXS) were employed to provide a comprehensive characterization of this novel hybrid organic-inorganic interface, the tailoring of which is likely to be generally applicable to improve the function and stability of a broad range of membrane proteins containing water-soluble domains.

  • 17. Liu, H J
    et al.
    Guo, J H
    Yin, Y D
    Augustsson, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap, Mjukröntgenfysik.
    Dong, C L
    Nordgren, Joseph
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap, Mjukröntgenfysik.
    Chang, C L
    Alivisatos, P
    Thornton, G
    Ogletree, D G
    Requejo, F G
    de Groot, F
    Salmeron, M
    Electronic structure of cobalt nanocrystals suspended in liquid2007Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 7, nr 7, s. 1919-1922Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The electronic structure of cobalt nanocrystals suspended in liquid as a function of size has been investigated using in situ X-ray absorptionand emission spectroscopy. A sharp absorption peak associated with the ligand molecules is found that increases in intensity upon reducingthe nanocrystal size. X-ray Raman features due to d−d and to charge-transfer excitations of ligand molecules are identified. The study revealsthe local symmetry of the surface of E-Co phase nanocrystals, which originates from a dynamic interaction between Co nanocrystals andsurfactant + solvent molecules.

  • 18. Marinova, Maya
    et al.
    Rault, Julien E.
    Gloter, Alexandre
    Nemsak, Slavomir
    Pálsson, Gunnar Karl
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Rueff, Jean-Pascal
    Fadley, Charles S.
    Carretero, Cecile
    Yamada, Hiroyuki
    March, Katia
    Garcia, Vincent
    Fusil, Stephane
    Barthelemy, Agnes
    Stephan, Odile
    Colliex, Christian
    Bibes, Manuel
    Depth Profiling Charge Accumulation from a Ferroelectric into a Doped Mott Insulator2015Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 15, nr 4, s. 2533-2541Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The electric field control of functional properties is a crucial goal in oxide-based electronics. Nonvolatile switching between different resistivity or magnetic states in an oxide channel can be achieved through charge accumulation or depletion from an adjacent ferroelectric. However, the way in which charge distributes near the interface between the ferroelectric and the oxide remains poorly known, which limits our understanding of such switching effects. Here, we use a first-of-a-kind combination of scanning transmission electron microscopy with electron energy loss spectroscopy, near-total-reflection hard X-ray photoemission spectroscopy, and ab initio theory to address this issue. We achieve a direct, quantitative, atomic-scale characterization of the polarization-induced charge density changes at the interface between the ferroelectric BiFeO3 and the doped Mott insulator Ca1-xCexMnO3, thus providing insight on how interface-engineering can enhance these switching effects.

  • 19.
    Nyström, Gustav
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Razaq, Aamir
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Strømme, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Nyholm, Leif
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Oorganisk kemi.
    Mihranyan, Albert
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Ultrafast All-Polymer Paper-Based Batteries2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 10, s. 3635-3639Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Conducting polymers for battery applications have been subject to numerous investigations during the last two decades. However, the functional charging rates and the cycling stabilities have so far been found to be insufficient for practical applications. These shortcomings can, at least partially, be explained by the fact that thick layers of the conducting polymers have been used to obtain sufficient capacities of the batteries. In the present letter, we introduce a novel nanostructured high-surface area electrode material for energy storage applications composed of cellulose fibers of algal origin individually coated with a 50 nm thin layer of polypyrrole. Our results show the hitherto highest reported charge capacities and charging rates for an all polymer paper-based battery. The composite conductive paper material is shown to have a specific surface area of 80 m(2) g(-1) and batteries based on this material can be charged with currents as high as 600 mA cm(-2) with only 6% loss in capacity over 100 subsequent charge and discharge cycles. The aqueous-based batteries, which are entirely based on cellulose and polypyrrole and exhibit charge capacities between 25 and 33 mAh g(-1) or 38-50 mAh g(-1) per weight of the active material, open up new possibilities for the production of environmentally friendly, cost efficient, up-scalable and lightweight energy storage systems.

  • 20.
    Pelucchi, E.
    et al.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    Watanabe, S.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    Leifer, Klaus
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Zhu, Q.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    Dwir, B.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    De Los Rios, P.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    Kapon, E.
    Ecole Polytechnique Fe´de´rale de Lausanne (EPFL), Institute of Theoretical Physics, CH-1015 Lausanne, Switzerland.
    Mechanisms of quantum dot energy engineering by metalorganic vapor phase epitaxy on patterned nonplanar substrates2007Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 7, nr 5, s. 1282-1285Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel technique for tuning the strength of quantum confinement in site-controlled semiconductor quantum dots (QDs) is introduced and investigated theoretically and experimentally. The method makes use of controlled local growth rates during metalorganic vapor phase epitaxy on patterned arrays of inverted pyramids. A model accounting for precursor migration and adatom incorporation predicts the tuning in QD thickness as a function of the pattern parameters. The results are in good agreement with experimental findings. This technique offers means for designing QD photonic structures with potential applications in QD-based cavity quantum electrodynamics and quantum information processing. © 2007 American Chemical Society.

  • 21.
    Peng, Xiangyang
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap.
    Ahuja, Rajeev
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och materialvetenskap.
    Symmetry Breaking Induced Bandgap in Epitaxial Graphene Layers on SiC2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 12, s. 4464-4468Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By performing density-functional calculations, we have investigated the electronic bandgap of single epitaxial and multiepitaxial graphene layers on SiC. The calculations show that a defect-free graphene layer above the carbon buffer layer is very flat and no bandgap is found in the Dirac bands. By introducing a finite density of Stone-Wales defects in the graphene layer(s), we find that a bandgap is opened and decreases as the thickness of graphene layers increases, in good agreement with experiments. The band splitting and the charge distribution vary greatly with the number of graphene layers. The bandgap opening is due to the symmetry breaking within the single graphene layer. The narrowing of the bandgap in multiple graphene layers is induced by interlayer interaction.

  • 22.
    Persson, Fredrik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för cell- och molekylärbiologi, Beräknings- och systembiologi. Uppsala universitet, Science for Life Laboratory, SciLifeLab.
    Fritzsche, Joachim
    Mir, Kalim U.
    Modesti, Mauro
    Westerlund, Fredrik
    Tegenfeldt, Jonas O.
    Lipid-Based Passivation in Nanofluidics2012Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 12, nr 5, s. 2260-2265Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stretching DNA in nanochannels is a useful tool for direct, visual studies of genomic DNA at the single molecule level. To facilitate the study of the interaction of linear DNA with proteins in nanochannels, we have implemented a highly effective passivation scheme based on lipid bilayers. We demonstrate virtually complete long-term passivation of nanochannel surfaces to a range of relevant reagents, including streptavidin-coated quantum dots, RecA proteins, and RecA-DNA complexes. We show that the performance of the lipid bilayer is significantly better than that of standard bovine serum albumin-based passivation. Finally, we show how the passivated devices allow us to monitor single DNA cleavage events during enzymatic degradation by DNase I. We expect that our approach will open up for detailed, systematic studies of a wide range of protein-DNA interactions with high spatial and temporal resolution.

  • 23.
    Prasongkit, Jariyanee
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Grigoriev, Anton
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Pathak, Biswarup
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Ahuja, Rajeev
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Scheicher, Ralph H.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Transverse Conductance of DNA Nucleotides in a Graphene Nanogap from First Principles2011Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 11, nr 5, s. 1941-1945Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The fabrication of nanopores in atomically thin graphene has recently been achieved, and translocation of DNA has been demonstrated. Taken together with an earlier proposal to use graphene nanogaps for the purpose of DNA sequencing, this approach can resolve the technical problem of achieving single-base resolution in electronic nucleobase detection. We have theoretically evaluated the performance of a graphene nanogap setup for the purpose of whole-genome sequencing, by employing density functional theory and the nonequilibrium Green's function method to investigate the transverse conductance properties of nucleotides inside the gap. In particular, we determined the electrical tunneling current variation at finite bias due to changes in the nucleotides orientation and lateral position. Although the resulting tunneling current is found to fluctuate over several orders of magnitude, a distinction between the four DNA bases appears possible, thus ranking the approach promising for rapid whole-genome sequencing applications.

  • 24. Preobrajenski, A. B.
    et al.
    Ng, M. L.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik V.
    Vinogradov, N. A.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik V.
    Vinogradov, S
    Lundgren, E
    Mikkelsen, A
    Mårtensson, N
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Fysiska institutionen, Fysik V.
    Impact of Oxygen Coadsorption on Intercalation of Cobalt under the h-BN Nanomesh2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 9, nr 7, s. 2780-2787Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The process of penetration of cobalt atoms through the h-BN nanomesh on Rh(111) is investigated with both spectroscopic and microscopic techniques. It is discovered that oxygen coadsorption can drastically modify the physical properties and behavior of the deposited Co clusters upon postannealing. In the absence of oxygen, Co forms small nanoparticles in the pores (bonding parts) of the h-BN nanomesh, which start to agglomerate at elevated temperatures without any considerable intercalation. However, even a tiny amount of coadsorbed oxygen reduces cobalt agglomeration and greatly promotes its intercalation and trapping under h-BN. The oxygen exposure necessary for a complete intercalation of 1-2 monolayers of Co is very low, and the formation of oxidic species can be easily avoided, The nanomesh structure remains intact upon intercalating submonolayer amounts of Co, while further intercalation gradually distorts and finally destroys the periodic corrugation. Fortunately, this process is not accompanied by damaging the h-BN sheet itself, and the original structure can be restored by removing Co upon annealing at higher temperatures.

  • 25. Preobrajenski, Alexei
    et al.
    May Ling, Ng
    Vinogradov, N. A.
    Vinogradov, A. S.
    Lundgren, Edvin
    Mikkelsen, Anders
    Mårtensson, Nils
    Impact of coadsorption on intercalation of cobalt under the h-BN nanomesh2009Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 7Artikkel i tidsskrift (Fagfellevurdert)
  • 26. Rollinger, Markus
    et al.
    Thielen, Philip
    Melander, Emil
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Östman, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Kapaklis, Vassilios
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Obry, Björn
    Tech Univ Kaiserslautern, Fachbereich Phys, D-67663 Kaiserslautern, Germany;Tech Univ Kaiserslautern, Forschungszentrum OPTIMAS, D-67663 Kaiserslautern, Germany.
    Cinchetti, Mirko
    García-Martín, Antonio
    Aeschlimann, Martin
    Papaioannou, Evangelos Th.
    Fachbereich Physik and Forschungszentrum OPTIMAS, Technische Universität Kaiserslautern.
    Light Localization and Magneto-Optic Enhancement in Ni Antidot Arrays2016Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 16, nr 4, s. 2432-2438Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    We reveal an explicit strategy to design the magneto-optic response of a magneto-plasmonic crystal by correlating near- and far-fields effects. We use photoemission electron microscopy to map the spatial distribution of the electric near-field on a nanopatterned magnetic surface that supports plasmon polaritons. By using different photon energies and polarization states of the incident light we reveal that the electric near-field is either concentrated in spots forming a hexagonal lattice with the same symmetry as the Ni nanopattern or in stripes oriented along the Gamma-K direction of the lattice and perpendicular to the polarization direction. We show that the polarization-dependent near-field enhancement on the patterned surface is directly correlated to both the excitation of surface plasmon polaritons on the patterned surface as well as the enhancement of the polar magneto-optical Kerr effect. We obtain a relationship between the size of the enhanced magneto optical behavior and the polarization and wavelength of optical excitation. The engineering of the magneto-optic response based on the plasmon-induced modification of the optical properties introduces the concept of a magneto-plasmonic meta-structure.

  • 27. Rudberg, Elias
    et al.
    Salek, Pawel
    Luo, Yi
    Nonlocal exchange interaction removes half-metallicity in graphene nanoribbons2007Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 7, nr 8, s. 2211-2213Artikkel i tidsskrift (Fagfellevurdert)
  • 28.
    Saygun, T.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Bylin, J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Hammar, Henning
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Fransson, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialfysik.
    Voltage-Induced Switching Dynamics of a Coupled Spin Pair in a Molecular Junction2016Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 16, nr 4, s. 2824-2829Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Molecular spintronics is made possible by the coupling between electronic configuration and magnetic polarization of the molecules. For control and application of the individual molecular states, it is necessary to both read and write their spin states. Conventionally, this is achieved by means of external magnetic fields or ferromagnetic contacts, which may change the intentional spin state and may present additional challenges when downsizing devices. Here, we predict that coupling magnetic molecules together opens up possibilities for all electrical control of both the molecular spin states as well as the current flow through the system. By tuning between the regimes of ferromagnetic and antiferromagnetic exchange interaction, the current can be at least an order of magnitude enhanced or reduced. The effect is susceptible to the tunnel coupling and molecular level alignment that can be used to achieve current rectification.

  • 29.
    Serrano, I. G.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Molekyl- och kondenserade materiens fysik.
    Panda, Jaganandha
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Molekyl- och kondenserade materiens fysik.
    Denoel, Fernand
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets fysik.
    Vallin, Örjan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Phuyal, Dibya
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Molekyl- och kondenserade materiens fysik.
    Karis, Olof
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Molekyl- och kondenserade materiens fysik.
    Kamalakar, M. Venkata
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Molekyl- och kondenserade materiens fysik.
    Two-Dimensional Flexible High Diffusive Spin Circuits2019Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, nr 2, s. 666-673Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Owing to their unprecedented electronic properties, graphene and two-dimensional (2D) crystals have brought fresh opportunities for advances in planar spintronic devices. Graphene is an ideal medium for spin transport while being an exceptionally resilient material for flexible nanoelectronics. However, these extraordinary traits have never been combined to create flexible graphene spin circuits. Realizing such circuits could lead to bendable strain-spin sensors, as well as a unique platform to explore pure spin current based operations and low-power 2D flexible nanoelectronics. Here, we demonstrate graphene spin circuits on flexible substrates for the first time. Despite the rough topography of the flexible substrates, these circuits prepared with chemical vapor deposited monolayer graphene reveal an efficient room temperature spin transport with distinctively large spin diffusion coefficients ∼0.2 m2 s–1. Compared to earlier graphene devices on Si/SiO2 substrates, such values are up to 20 times larger, leading to one order higher spin signals and an enhanced spin diffusion length ∼10 μm in graphene-based nonlocal spin valves fabricated using industry standard systems. This high performance arising out of a characteristic substrate terrain shows promise of a scalable and flexible platform towards flexible 2D spintronics. Our innovation is a key step for the exploration of strain-dependent 2D spin phenomena and paves the way for flexible graphene spin memory–logic units and planar spin sensors.

  • 30.
    Shah, Furqan
    et al.
    Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy, Department of Materials Science and Engineering, McMaster University, Hamilton .
    Lee, Bryan
    School of Biomedical Engineering, McMaster University, Hamilton.
    Tedesco, James
    Department of Materials Science and Engineering, McMaster University, Hamilton.
    Larsson Wexell, Cecilia
    Department of Biomaterials, Sahlgrenska Academy at University, Department of Oral and Maxillofacial Surgery, Sö dra Älvsborg Hospital of Gothenburg, BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therap.
    Persson, Cecilia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Thomsen, Peter
    Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg,BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy .
    Grandfield, Kathryn
    School of Biomedical Engineering, McMaster University, Hamilton, Department of Materials Science and Engineering, McMaster University, Hamilton.
    Palmquist, Anders
    Department of Biomaterials, Sahlgrenska Academy at University of Gothenburg, BIOMATCELL VINN Excellence Center of Biomaterials and Cell Therapy .
    Micrometre-sized magnesium whitlockite crystals in micropetrosis of bisphosphonate-exposed human alveolar bone2017Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 17, nr 10, s. 6210-6216Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Osteocytes are contained within spaces called lacunae and play a central role in bone remodelling. Administered frequently to prevent osteoporotic fractures, antiresorptive agents such as bisphosphonates suppress osteocyte apoptosis and may be localized within osteocyte lacunae. Bisphosphonates also reduce osteoclast viability and thereby hinder the repair of damaged tissue. Osteocyte lacunae contribute to toughening mechanisms. Following osteocyte apoptosis, the lacunar space undergoes mineralization, termed “micropetrosis”. Hypermineralized lacunae are believed to increase bone fragility. Using nanoanalytical electron microscopy with complementary spectroscopic and crystallographic experiments, postapoptotic mineralization of osteocyte lacunae in bisphosphonate-exposed human bone was investigated. We report an unprecedented presence of ∼80 nm to ∼3 μm wide, distinctly faceted, magnesium whitlockite [Ca18Mg2(HPO4)2(PO4)12] crystals and consequently altered local nanomechanical properties. These findings have broad implications on the role of therapeutic agents in driving biomineralization and shed new insights into a possible relationship between bisphosphonate exposure, availability of intracellular magnesium, and pathological calcification inside lacunae.

  • 31.
    Strömberg, Mattias
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Göransson, Jenny
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Gunnarsson, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets fysik.
    Nilsson, Mats
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Svedlindh, Peter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets fysik.
    Strømme, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Sensitive molecular diagnostics using volume-amplified magnetic nanobeads2008Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 8, nr 3, s. 816-821Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this letter, we demonstrate a new principle for diagnostics based on DNA sequence detection using single-stranded oligonucleotide tagged magnetic nanobeads. The target DNA is recognized and volume-amplified to large coils by circularization of linear padlock probes through probe hybridization and ligation, followed by rolling circle amplification (RCA). Upon hybridization of the nanobeads in the RCA coils, the complex magnetization spectrum of the beads changes dramatically, induced by the attached volume-amplified target molecules. We show that the magnetization spectrum of the nanobeads can be used for concentration determination of RCA coils down to the pM range, thus creating the opportunity for nonfluorescence-based cost-efficient high-sensitivity diagnostics tool. We also show that the bead incorporation in the coils is diffusion-controlled and consequently may be accelerated by incubating the sample at higher temperatures.

  • 32. Sytnyk, Mykhailo
    et al.
    Kirchschlager, Raimund
    Bodnarchuk, Maryna I.
    Primetzhofer, Daniel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Tillämpad kärnfysik.
    Kriegner, Dominik
    Enser, Herbert
    Stangl, Julian
    Bauer, Peter
    Voith, Michael
    Hassel, Achim Walter
    Krumeich, Frank
    Ludwig, Frank
    Meingast, Arno
    Kothleitner, Gerald
    Kovalenko, Maksym V.
    Heiss, Wolfgang
    Tuning the Magnetic Properties of Metal Oxide Nanocrystal Heterostructures by Cation Exchange2013Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 13, nr 2, s. 586-593Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For three types of colloidal magnetic nanocrystals, we demonstrate that postsynthetic cation exchange enables tuning of the nanocrystal's magnetic properties and achieving characteristics not obtainable by conventional synthetic routes. While the cation exchange procedure, performed in solution phase approach, was restricted so far to chalcogenide based semiconductor nanocrystals, here ferrite-based nanocrystals were subjected to a Fe2+ to Co2+ cation exchange procedure. This allows tracing of the compositional modifications by systematic and detailed magnetic characterization. In homogeneous magnetite nanocrystals and in gold/magnetite core shell nanocrystals the cation exchange increases the coercivity field, the remanence magnetization, as well as the superparamagnetic blocking temperature. For core/shell nanoheterostructures a selective doping of either the shell or predominantly of the core with Co2+ is demonstrated. By applying the cation exchange to FeO/CoFe2O4 core/shell nanocrystals the Neel temperature of the core material is increased and exchange-bias effects are enhanced so that vertical shifts of the hysteresis loops are obtained which are superior to those in any other system.

  • 33.
    Vallhov, Helen
    et al.
    Karolinska Institutet.
    Gabrielsson, Susanne
    Karolinska Institutet.
    Strömme, Maria
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Scheynius, Annika
    Karolinska Institutet.
    Garcia Bennett, Alfonso E
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Nanoteknologi och funktionella material.
    Mesoporous silica particles induce size dependent effects on human dendritic cells2007Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 7, nr 12, s. 3576-3582Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    The effects of mesoporous silica nano- (270 nm) and microparticles (2.5 μm) with surface areas above 500 m2/g were evaluated on human monocyte-derived dendritic cells (MDDC). Size- and concentration-dependent effects were seen where the smaller particles and lower concentrations affected MDDC to a minor degree compared to the larger particles and higher concentrations, both in terms of viability, uptake, and immune regulatory markers. Our findings support the further development of mesoporous silica particles in drug and vaccine delivery systems.

  • 34.
    Zhang, Pan
    et al.
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Xia, Min
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Zhuge, Fuwei
    Huazhong Univ Sci & Technol, Sch Mat Sci & Engn, Wuhan 430074, Hubei, Peoples R China.
    Zhou, Yue
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Wang, Zhenyu
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Dong, Boyi
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Fu, Yaoyao
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Yang, Kecheng
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Li, Yi
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    He, Yuhui
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Scheicher, Ralph H.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Materialteori.
    Miao, Xiang Shui
    Huazhong Univ Sci & Technol, Wuhan Natl Lab Optoelect, Sch Opt & Elect Informat, Wuhan 430074, Hubei, Peoples R China.
    Nanochannel-Based Transport in an Interfacial Memristor Can Emulate the Analog Weight Modulation of Synapses2019Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, nr 7, s. 4279-4286Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By exploiting novel transport phenomena such as ion selectivity at the nanoscale, it has been shown that nanochannel systems can exhibit electrically controllable conductance, suggesting their potential use in neuromorphic devices. However, several critical features of biological synapses, particularly their conductance modulation, which is both memorable and gradual, have rarely been reported in these types of systems due to the fast flow property of typical inorganic electrolytes. In this work, we demonstrate that electrically manipulating the nanochannel conductance can result in nonvolatile conductance tuning capable of mimicking the analog behavior of synapses by introducing a room-temperature ionic liquid (IL) and a KCl solution into the two ends of a nanochannel system. The gradual conductance-tuning mechanism is identified through fluorescence measurements as the voltage-induced movement of the interface between the immiscible IL and KCl solution, while the successful memorization of the conductance tuning is ascribed to the large viscosity of the IL. We applied a nanochannel-based synapse to a handwritten digit-recognition task, reaching an accuracy of 94%. These promising results provide important guidance for the future design of nanochannel-based neuromorphic devices and the manipulation of nanochannel transport for computing.

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