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  • 1. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Asano, K.
    Atwood, W. B.
    Johannesson, G.
    Johnson, A. S.
    Ryde, Felix
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Ziegler, M.
    Conrad, Jan
    Mc Glynn, Sinéad
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Ylinen, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Moretti, Elena
    University and INFN of Trieste.
    A limit on the variation of the speed of light arising from quantum gravity effects2009Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 462, nr 7271, s. 331-334Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A cornerstone of Einstein's special relativity is Lorentz invariance-the postulate that all observers measure exactly the same speed of light in vacuum, independent of photon-energy. While special relativity assumes that there is no fundamental length-scale associated with such invariance, there is a fundamental scale (the Planck scale, l(Planck) approximate to 1.62 x 10(-33) cm or E-Planck = M(Planck)c(2) approximate to 1.22 x 10(19) GeV), at which quantum effects are expected to strongly affect the nature of space-time. There is great interest in the (not yet validated) idea that Lorentz invariance might break near the Planck scale. A key test of such violation of Lorentz invariance is a possible variation of photon speed with energy(1-7). Even a tiny variation in photon speed, when accumulated over cosmological light-travel times, may be revealed by observing sharp features in gamma-ray burst (GRB) light-curves(2). Here we report the detection of emission up to similar to 31GeV from the distant and short GRB090510. We find no evidence for the violation of Lorentz invariance, and place a lower limit of 1.2E(Planck) on the scale of a linear energy dependence (or an inverse wavelength dependence), subject to reasonable assumptions about the emission (equivalently we have an upper limit of l(Planck)/1.2 on the length scale of the effect). Our results disfavour quantum-gravity theories(3,6,7) in which the quantum nature of space-time on a very small scale linearly alters the speed of light.

  • 2. Abdo, A. A.
    et al.
    Ackermann, M.
    Ajello, M.
    Axelsson, Magnus
    Johannesson, G.
    Johnson, A. S.
    Ryde, Felix
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Sikora, M.
    Ylinen, Tomi
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    et al,
    A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 2792010Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 463, nr 7283, s. 919-923Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight(1). The size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. Here we report the coincidence of a gamma (gamma)-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and gamma-ray emission regions and indicates a highly ordered jet magnetic field. The results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 10(5) gravitational radii.

  • 3. Adriani, O.
    et al.
    Barbarino, G. C.
    Bazilevskaya, G. A.
    Bellotti, R.
    Boezio, M.
    Bogomolov, E. A.
    Bonechi, L.
    Bongi, M.
    Bonvicini, V.
    Bottai, S.
    Bruno, A.
    Cafagna, F.
    Campana, D.
    Carlson, Per
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Casolino, M.
    Castellini, G.
    De Pascale, M. P.
    De Rosa, G.
    De Simone, N.
    Di Felice, V.
    Galper, A. M.
    Grishantseva, L.
    Hofverberg, Petter
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Koldashov, S. V.
    Krutkov, S. Y.
    Kvashnin, A. N.
    Leonov, A.
    Malvezzi, V.
    Marcelli, L.
    Menn, W.
    Mikhailov, V. V.
    Mocchiutti, E.
    Orsi, Silvio
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Osteria, G.
    Papini, P.
    Pearce, Mark
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Picozza, P.
    Ricci, M.
    Ricciarini, S. B.
    Simon, M.
    Sparvoli, R.
    Spillantini, P.
    Stozhkov, Y. I.
    Vacchi, A.
    Vannuccini, E.
    Vasilyev, G.
    Voronov, S. A.
    Yurkin, Y. T.
    Zampa, G.
    Zampa, N.
    Zverev, V. G.
    An anomalous positron abundance in cosmic rays with energies 1.5-100 GeV2009Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 458, nr 7238, s. 607-609Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Antiparticles account for a small fraction of cosmic rays and are known to be produced in interactions between cosmic-ray nuclei and atoms in the interstellar medium(1), which is referred to as a 'secondary source'. Positrons might also originate in objects such as pulsars(2) and microquasars(3) or through dark matter annihilation(4), which would be 'primary sources'. Previous statistically limited measurements(5-7) of the ratio of positron and electron fluxes have been interpreted as evidence for a primary source for the positrons, as has an increase in the total electron+positron flux at energies between 300 and 600 GeV (ref. 8). Here we report a measurement of the positron fraction in the energy range 1.5-100 GeV. We find that the positron fraction increases sharply overmuch of that range, in a way that appears to be completely inconsistent with secondary sources. We therefore conclude that a primary source, be it an astrophysical object or dark matter annihilation, is necessary.

  • 4. Babaev, Egor
    et al.
    Sudbo, A.
    Ashcroft, N. W.
    A superconductor to superfluid phase transition in liquid metallic hydrogen2004Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 431, nr 7009, s. 666-668Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although hydrogen is the simplest of atoms, it does not form the simplest of solids or liquids. Quantum effects in these phases are considerable (a consequence of the light proton mass) and they have a demonstrable and often puzzling influence on many physical properties(1), including spatial order. To date, the structure of dense hydrogen remains experimentally elusive(2). Recent studies of the melting curve of hydrogen(3,4) indicate that at high (but experimentally accessible) pressures, compressed hydrogen will adopt a liquid state, even at low temperatures. In reaching this phase, hydrogen is also projected to pass through an insulator-to-metal transition. This raises the possibility of new state of matter: a near ground-state liquid metal, and its ordered states in the quantum domain. Ordered quantum fluids are traditionally categorized as superconductors or superfluids; these respective systems feature dissipationless electrical currents or mass flow. Here we report a topological analysis of the projected phase of liquid metallic hydrogen, finding that it may represent a new type of ordered quantum fluid. Specifically, we show that liquid metallic hydrogen cannot be categorized exclusively as a superconductor or superfluid. We predict that, in the presence of a magnetic field, liquid metallic hydrogen will exhibit several phase transitions to ordered states, ranging from superconductors to superfluids.

  • 5.
    Belonoshko, Anatoly B.
    et al.
    KTH, Tidigare Institutioner                               , Fysik.
    Ahuja, Rajeev
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Johansson, Börje
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Stability of the body-centred-cubic phase of iron in the Earth's inner core2003Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 424, nr 6952, s. 1032-1034Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Iron is thought to be the main constituent of the Earth's core(1), and considerable efforts(2-14) have therefore been made to understand its properties at high pressure and temperature. While these efforts have expanded our knowledge of the iron phase diagram, there remain some significant inconsistencies, the most notable being the difference between the 'low' and 'high' melting curves(15). Here we report the results of molecular dynamics simulations of iron based on embedded atom models fitted to the results of two implementations of density functional theory. We tested two model approximations and found that both point to the stability of the body-centred-cubic (b.c.c.) iron phase at high temperature and pressure. Our calculated melting curve is in agreement with the 'high' melting curve, but our calculated phase boundary between the hexagonal close packed (h. c. p.) and b.c.c. iron phases is in good agreement with the 'low' melting curve. We suggest that the h.c.p.-b.c.c. transition was previously misinterpreted as a melting transition, similar to the case of xenon(16-18), and that the b.c.c. phase of iron is the stable phase in the Earth's inner core.

  • 6.
    Cao, Lina
    et al.
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Liu, Wei
    Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei, Anhui, Peoples R China..
    Luo, Qiquan
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Yin, Ruoting
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Wang, Bing
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Weissenrieder, Jonas
    KTH, Skolan för teknikvetenskap (SCI).
    Soldemo, Markus
    KTH, Skolan för teknikvetenskap (SCI).
    Yan, Huan
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Lin, Yue
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China..
    Sun, Zhihu
    Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei, Anhui, Peoples R China..
    Ma, Chao
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China..
    Zhang, Wenhua
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China..
    Chen, Si
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Wang, Hengwei
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Guan, Qiaoqiao
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China..
    Yao, Tao
    Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei, Anhui, Peoples R China..
    Wei, Shiqiang
    Univ Sci & Technol China, Natl Synchrotron Radiat Lab, Hefei, Anhui, Peoples R China..
    Yang, Jinlong
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Collaborat Innovat Ctr Chem Energy Mat iChEM, Hefei, Anhui, Peoples R China..
    Lu, Junling
    Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Dept Chem Phys, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, Collaborat Innovat Ctr Chem Energy Mat iChEM, Hefei, Anhui, Peoples R China.;Univ Sci & Technol China, CAS Key Lab Mat Energy Convers, Hefei, Anhui, Peoples R China..
    Atomically dispersed iron hydroxide anchored on Pt for preferential oxidation of CO in H-22019Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 565, nr 7741, s. 631-635Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Proton-exchange-membrane fuel cells (PEMFCs) are attractive next-generation power sources for use in vehicles and other applications(1), with development efforts focusing on improving the catalyst system of the fuel cell. One problem is catalyst poisoning by impurity gases such as carbon monoxide (CO), which typically comprises about one per cent of hydrogen fuel(2-4). A possible solution is on-board hydrogen purification, which involves preferential oxidation of CO in hydrogen (PROX)(3-7). However, this approach is challenging(8-15) because the catalyst needs to be active and selective towards CO oxidation over a broad range of low temperatures so that CO is efficiently removed (to below 50 parts per million) during continuous PEMFC operation (at about 353 kelvin) and, in the case of automotive fuel cells, during frequent cold-start periods. Here we show that atomically dispersed iron hydroxide, selectively deposited on silica-supported platinum (Pt) nanoparticles, enables complete and 100 per cent selective CO removal through the PROX reaction over the broad temperature range of 198 to 380 kelvin. We find that the mass-specific activity of this system is about 30 times higher than that of more conventional catalysts consisting of Pt on iron oxide supports. In situ X-ray absorption fine-structure measurements reveal that most of the iron hydroxide exists as Fe-1(OH)(x) clusters anchored on the Pt nanoparticles, with density functional theory calculations indicating that Fe-1(OH)(x)-Pt single interfacial sites can readily react with CO and facilitate oxygen activation. These findings suggest that in addition to strategies that target oxide-supported precious-metal nanoparticles or isolated metal atoms, the deposition of isolated transition-metal complexes offers new ways of designing highly active metal catalysts.

  • 7.
    Cederström, Björn
    et al.
    KTH, Tidigare Institutioner                               , Fysik.
    Cahn, R. N.
    Danielsson, Mats
    KTH, Tidigare Institutioner                               , Fysik.
    Lundqvist, M.
    Nygren, D. R.
    Focusing hard X-rays with old LPs2000Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 404, nr 6781, s. 951-951Artikel i tidskrift (Refereegranskat)
  • 8.
    Cederwall, Bo
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Ghazi Moradi, Farnaz
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Bäck, Torbjörn
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Johnson, Arne
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Blomqvist, Jan-Erik
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Clément, E.
    Grand Accélérateur National d´lons Lourds, Cean Cedex, France.
    de France, G.
    Grand Accélérateur National d´lons Lourds, Cean Cedex, France.
    Wadsworth, R.
    Department of Physics, University of York, UK.
    Andgren, Karin
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Lagergren, Karin
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Dijon, A.
    Grand Accélérateur National d´lons Lourds, Cean Cedex, France.
    Jaworski, G.
    Heavy Ion Laboratory, Univeristy of Warsaw, Warsaw, Poland.
    Liotta, Roberto
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik.
    Qi, Chong
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Nyakó, B. M.
    Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary.
    Nyberg, J.
    Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden.
    Palacz, M.
    Heavy Ion Laboratory, Univeristy of Warsaw, Warsaw, Poland.
    Al-Azri, H.
    Department of Physics, University of York, UK.
    Algora, A.
    IFIC, CSIC University of Valencia, Valencia, Spain.
    de Angelis, G.
    Instituto Nazionael di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, Italy.
    Atac, Ayse
    KTH, Skolan för teknikvetenskap (SCI).
    Bhattacharyya, S.
    Grand Accélérateur National d´lons Lourds, Cean Cedex, France.
    Brock, T.
    Department of Physics, University of York, York, UK.
    Brown, J. R.
    Department of Physics, University of York, York, UK.
    Davies, P.
    Department of Physics, University of York, York, UK.
    Di Nitto, A.
    Dipartimento di Scienze Fisiche, Universitá di Napoli and Instituto Nazionale di Fisica Nucleare, Napoli, Italy.
    Dombrádi, Zs.
    Institute of Nuclear Research of the Hungarian Academy of Science, Debrecen, Hungary.
    Gadea, A.
    IFIC, CSIC, University of Valencia, Valencia, Spain.
    Gál, J.
    Institute of Nuclear Research of the Hungarian Academy of Science, Debrecen, Hungary.
    Hadinia, Baharak
    KTH, Skolan för teknikvetenskap (SCI), Fysik.
    Johnston-Theasby, F.
    Department of Physics, University of York, York, UK.
    Joshi, P.
    Department of Physics, University of York, York, UK.
    Juhász, K.
    Department of Information Technology, Universty of Debrecen, Debrecen, Hungary.
    Julin, R.
    Department of Physics, University of Jyväskylä, Jyväskylä, Finland.
    Jungclaus, A.
    Instituto de Estructura de la Materia, Madrid, Spain .
    Kalinka, G.
    Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary.
    Kara, S. O.
    Department of Physics, Ankara University, Tandogan Ankarar, Turkey.
    Khaplanov, Anton
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Kownacki, J.
    Heavy Ion Laboratory, Universty of Warsaw, Warsaw, Poland.
    La Rana, G.
    Dipartimento di Scienze Fisiche, Universitá di Napoli and Instituto Nazionale di Fisica Nucleare, Napoli, Italy.
    Lenzi, S. M.
    Dipartimento di Fisica dell'Universitá di Padova and Instituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova, Italy.
    Molnár, J.
    Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary.
    Moro, R.
    Dipartimento di Scienze Fisiche, Universitá di Napoli and Instituto Nazionale di Fisica Nucleare, Napoli, Italy.
    Napoli, D. R.
    Instituto Nazionale di Fisica Nucleare, Laboratori Natzionali di Legnaro, Legnaro, Italy.
    Nara Singh, B. S.
    Department of Physics, University of York, York, UK.
    Persson, Andreas
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnfysik.
    Recchia, F.
    Dipartimento di Fisica dell'Universitá di Padova and Instituto Nazionale di Fisica Nucleare, Sezione di Padova, Padova, Italy.
    Sandzelius, Mikael
    KTH, Skolan för teknikvetenskap (SCI), Fysik.
    Scheurer, J. -N
    Université Bordeaux, Centre d'Etudes Nucléaires de Bordeaux Gradignan, Gradignan, France.
    Sletten, G.
    The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
    Sohler, D.
    Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary.
    Söderström, P. -A
    Department of Physics and Astromony, Uppsala University, Uppsala, Sweden.
    Taylor, M. J.
    Department of Physics, University of York, York, UK.
    Timár, J.
    Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen, Hungary.
    Valiente-Dobón, J. J.
    instituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Legnaro, Italy.
    Vardaci, E.
    Dipartimento di Scienze Fisiche, Universitá di Napoli and Instituto Nazionale di Fisica Nucleare, Napoli, Italy.
    Williams, S.
    TRIUMF, Vancouver, British Columbia, Canada.
    Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd2011Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 469, nr 7328, s. 68-71Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.

  • 9.
    Contreras, F.-Xabier
    et al.
    Heidelberg University.
    Ernst, Andreas M
    Heidelberg University.
    Haberkant, Per
    Heidelberg University.
    Björkholm, Patrik
    Stockholm University.
    Lindahl, Erik
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Beräkningsbiofysik.
    Gönen, Başak
    Tischer, Christian
    Heidelberg University.
    Elofsson, Arne
    Stockholm University.
    von Heijne, Gunnar
    Stockholm University.
    Thiele, Christoph
    Heidelberg University.
    Pepperkok, Rainer
    Heidelberg University.
    Wieland, Felix
    Heidelberg University.
    Brügger, Britta
    Heidelberg University.
    Molecular recognition of a single sphingolipid species by a protein's transmembrane domain2012Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 481, nr 7382, s. 525-529Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Functioning and processing of membrane proteins critically depend on the way their transmembrane segments are embedded in the membrane. Sphingolipids are structural components of membranes and can also act as intracellular second messengers. Not much is known of sphingolipids binding to transmembrane domains (TMDs) of proteins within the hydrophobic bilayer, and how this could affect protein function. Here we show a direct and highly specific interaction of exclusively one sphingomyelin species, SM 18, with the TMD of the COPI machinery protein p24 (ref. 2). Strikingly, the interaction depends on both the headgroup and the backbone of the sphingolipid, and on a signature sequence (VXXTLXXIY) within the TMD. Molecular dynamics simulations show a close interaction of SM 18 with the TMD. We suggest a role of SM 18 in regulating the equilibrium between an inactive monomeric and an active oligomeric state of the p24 protein, which in turn regulates COPI-dependent transport. Bioinformatic analyses predict that the signature sequence represents a conserved sphingolipid-binding cavity in a variety of mammalian membrane proteins. Thus, in addition to a function as second messengers, sphingolipids can act as cofactors to regulate the function of transmembrane proteins. Our discovery of an unprecedented specificity of interaction of a TMD with an individual sphingolipid species adds to our understanding of why biological membranes are assembled from such a large variety of different lipids.

  • 10. D'Alisa, Giacomo
    et al.
    Armiero, Marco
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Filosofi och teknikhistoria, Historiska studier av teknik, vetenskap och miljö.
    De Rosa, Salvatore Paolo
    Rethink Campania's toxic-waste scandal2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 509, nr 7501, s. 427-427Artikel i tidskrift (Refereegranskat)
  • 11.
    Dubrovinsky, L.
    et al.
    Bayerisches Geoinstitut, Universität Bayreuth.
    Dubrovinskaia, N.
    Bayerisches Geoinstitut, Universität Bayreuth.
    Langenhorst, F.
    Bayerisches Geoinstitut, Universität Bayreuth.
    Dobson, D.
    Bayerisches Geoinstitut, Universität Bayreuth.
    Rubie, D.
    Bayerisches Geoinstitut, Universität Bayreuth.
    Gessgmann, C.
    Max-Planck-Institut für Chemie, Mainz.
    Abrikosov, I. A.
    Condensed Matter Theory Group, Department of Physics, Uppsala University.
    Johansson, Börje
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Baykov, Vitaly
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Vitos, Levente
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Le Bihan, T.
    European Synchrotron Radiation Facility, Grenoble.
    Crichton, W. A.
    European Synchrotron Radiation Facility, Grenoble.
    Dmitriev, V.
    Swiss-Norwegian Beam Lines at ESRF, Grenoble.
    Weber, H. P.
    Swiss-Norwegian Beam Lines at ESRF, Grenoble.
    Iron-silica interaction at extreme conditions and the electrically conducting layer at the base of Earth's mantle2003Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 422, nr 6927, s. 58-61Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The boundary between the Earth's metallic core and its silicate mantle is characterized by strong lateral heterogeneity and sharp changes in density, seismic wave velocities, electrical conductivity and chemical composition(1-7). To investigate the composition and properties of the lowermost mantle, an understanding of the chemical reactions that take place between liquid iron and the complex Mg-Fe-Si-Al-oxides of the Earth's lower mantle is first required(8-15). Here we present a study of the interaction between iron and silica (SiO2) in electrically and laser-heated diamond anvil cells. In a multianvil apparatus at pressures up to 140 GPa and temperatures over 3,800 K we simulate conditions down to the core-mantle boundary. At high temperature and pressures below 40 GPa, iron and silica react to form iron oxide and an iron-silicon alloy, with up to 5 wt% silicon. At pressures of 85-140 GPa, however, iron and SiO2 do not react and iron-silicon alloys dissociate into almost pure iron and a CsCl-structured (B2) FeSi compound. Our experiments suggest that a metallic silicon-rich B2 phase, produced at the core-mantle boundary (owing to reactions between iron and silicate(2,9,10,13)), could accumulate at the boundary between the mantle and core and explain the anomalously high electrical conductivity of this region(6).

  • 12. Dubrovinsky, L. S.
    et al.
    Dubrovinskaia, N. A.
    Swamy, V.
    Muscat, J.
    Harrison, N. M.
    Ahuja, Rajeev
    Holm, B.
    Johansson, Börje
    KTH, Tidigare Institutioner                               , Materialvetenskap.
    Materials science - The hardest known oxide2001Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 410, nr 6829, s. 653-654Artikel i tidskrift (Refereegranskat)
  • 13. Dujon, B
    et al.
    Albermann, K
    Aldea, M
    Alexandraki, D
    Ansorge, W
    Arino, J
    Benes, V
    Bohn, C
    BolotinFukuhara, M
    Bordonne, R
    Boyer, J
    Camasses, A
    Casamayor, A
    Casas, C
    Cheret, G
    Cziepluch, C
    DaignanFornier, B
    Dang, V
    deHaan, M
    Delius, H
    Durand, P
    Fairhead, C
    Feldmann, H
    Gaillon, L
    Galisson, F
    Gamo, J
    Gancedo, C
    Goffeau, A
    Goulding, E
    Grivell, A
    Habbig, B
    Hand, J
    Hani, J
    Hattenhorst, U
    Hebling, U
    Hernando, Y
    Herrero, E
    Heumann, K
    Hiesel, R
    Hilger, F
    Hofmann, B
    Hollenberg, P
    Hughes, B
    Jauniaux, C
    Kalogeropoulos, A
    Katsoulou, C
    Kordes, E
    Lafuente, J
    Landt, O
    Louis, J
    Maarse, C
    Madania, A
    Mannhaupt, G
    Marck, C
    Martin, P
    Mewes, W
    Michaux, G
    Paces, V
    ParleMcDermott, G
    Pearson, M
    Perrin, A
    Pettersson, B
    Poch, O
    Pohl, M
    Poirey, R
    Portetelle, D
    Pujol, A
    Purnelle, B
    Rad, R
    Rechmann, S
    Schwager, C
    Schweizer, M
    Sor, F
    Sterky, Fredrik
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Tarassov, A
    Teodoru, C
    Tettelin, H
    Thierry, A
    Tobiasch, E
    Tzermia, M
    Uhlen, Mathias
    KTH, Tidigare Institutioner                               , Bioteknologi.
    Unseld, M
    Valens, M
    Vandenbol, M
    Vetter, I
    Vicek, C
    Voet, M
    Volckaert, G
    Voss, H
    Wambutt, R
    Wedler, H
    Wiemann, S
    Winsor, B
    Wolfe, H
    Zollner, A
    Zumstein, E
    Kleine, K
    The nucleotide sequence of Saccharomyces cerevisiae chromosome XV1997Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 387, nr 6632, s. 98-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chromosome XV was one of the last two chromosomes of Saccharomyces cerevisiae to be discovered(1). It is the third-largest yeast chromosome after chromosomes XII and IV, and is very similar in size to chromosome VII. It alone represents 9% of the yeast genome (8% if ribosomal DNA is included). When systematic sequencing of chromosome XV was started, 93 genes or markers were identified, and most of them were mapped(2). However, very little else was known about chromosome XV which, in contrast to shorter chromosomes, had not been the object of comprehensive genetic or molecular analysis. It was therefore decided to start sequencing chromosome XV only in the third phase of the European Yeast Genome Sequencing Programme, after experience was gained on chromosomes III, XI and II (refs 3-5). The sequence of chromosome XV has been determined from a set of partly overlapping cosmid clones derived from a unique yeast strain, and physically mapped at 3.3-kilobase resolution before sequencing. As well as numerous new open reading frames (ORFs) and genes encoding tRNA or small RNA molecules, the sequence of 1,091,283 base pairs confirms the high proportion of orphan genes and reveals a number of ancestral and successive duplications with other yeast chromosomes.

  • 14. Egorov, A. V.
    et al.
    Hamam, B. N.
    Fransén, Erik
    KTH, Tidigare Institutioner, Numerisk analys och datalogi, NADA.
    Hasselmo, M. E.
    Alonso, A. A.
    Graded persistent activity in entorhinal cortex neurons2002Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 420, nr 6912, s. 173-178Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Working memory represents the ability of the brain to hold externally or internally driven information for relatively short periods of time(1,2). Persistent neuronal activity is the elementary process underlying working memory but its cellular basis remains unknown. The most widely accepted hypothesis is that persistent activity is based on synaptic reverberations in recurrent circuits. The entorhinal cortex in the parahippocampal region is crucially involved in the acquisition, consolidation and retrieval of long-term memory traces for which working memory operations are essential(2). Here we show that individual neurons from layer V of the entorhinal cortex-which link the hippocampus to extensive cortical regions(3)-respond to consecutive stimuli with graded changes in firing frequency that remain stable after each stimulus presentation. In addition, the sustained levels of firing frequency can be either increased or decreased in an input-specific manner. This firing behaviour displays robustness to distractors; it is linked to cholinergic muscarinic receptor activation, and relies on activity-dependent changes of a Ca2+-sensitive cationic current. Such an intrinsic neuronal ability to generate graded persistent activity constitutes an elementary mechanism for working memory.

  • 15.
    Fuso Nerini, Francesco
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystemanalys.
    Shore up support for climate action using SDGs correspondence2018Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 557, nr 7703Artikel i tidskrift (Refereegranskat)
  • 16.
    Fälthammar, Carl-Gunne
    et al.
    KTH, Tidigare Institutioner, Alfvénlaboratoriet. KTH, Skolan för elektro- och systemteknik (EES), Rymd- och plasmafysik.
    Akasofu, S.I.
    Alfvén, Hannes
    KTH, Tidigare Institutioner, Alfvénlaboratoriet. KTH, Skolan för elektro- och systemteknik (EES), Rymd- och plasmafysik.
    Significance of magnetospheric research for progress in astrophysics1978Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 275, s. 185-188Artikel i tidskrift (Refereegranskat)
  • 17. Haas, Brian J.
    et al.
    Kamoun, Sophien
    Zody, Michael C.
    Jiang, Rays H. Y.
    Handsaker, Robert E.
    Cano, Liliana M.
    Grabherr, Manfred
    Kodira, Chinnappa D.
    Raffaele, Sylvain
    Torto-Alalibo, Trudy
    Bozkurt, Tolga O.
    Bulone, Vincent
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Fugelstad, Johanna
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans2009Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 461, nr 7262, s. 393-398Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population(1). Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion(2). Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars(3,4). Here we report the sequence of the P. infestans genome, which at similar to 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for similar to 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.

  • 18. Hudson, Thomas J.
    et al.
    Anderson, Warwick
    Aretz, Axel
    Barker, Anna D.
    Bell, Cindy
    Bernabe, Rosa R.
    Bhan, M. K.
    Calvo, Fabien
    Eerola, Iiro
    Gerhard, Daniela S.
    Guttmacher, Alan
    Guyer, Mark
    Hemsley, Fiona M.
    Jennings, Jennifer L.
    Kerr, David
    Klatt, Peter
    Kolar, Patrik
    Kusuda, Jun
    Lane, David P.
    Laplace, Frank
    Lu, Youyong
    Nettekoven, Gerd
    Ozenberger, Brad
    Peterson, Jane
    Rao, T. S.
    Remacle, Jacques
    Schafer, Alan J.
    Shibata, Tatsuhiro
    Stratton, Michael R.
    Vockley, Joseph G.
    Watanabe, Koichi
    Yang, Huanming
    Yuen, Matthew M. F.
    Knoppers, M.
    Bobrow, Martin
    Cambon-Thomsen, Anne
    Dressler, Lynn G.
    Dyke, Stephanie O. M.
    Joly, Yann
    Kato, Kazuto
    Kennedy, Karen L.
    Nicolas, Pilar
    Parker, Michael J.
    Rial-Sebbag, Emmanuelle
    Romeo-Casabona, Carlos M.
    Shaw, Kenna M.
    Wallace, Susan
    Wiesner, Georgia L.
    Zeps, Nikolajs
    Lichter, Peter
    Biankin, Andrew V.
    Chabannon, Christian
    Chin, Lynda
    Clement, Bruno
    de Alava, Enrique
    Degos, Francoise
    Ferguson, Martin L.
    Geary, Peter
    Hayes, D. Neil
    Johns, Amber L.
    Nakagawa, Hidewaki
    Penny, Robert
    Piris, Miguel A.
    Sarin, Rajiv
    Scarpa, Aldo
    van de Vijver, Marc
    Futreal, P. Andrew
    Aburatani, Hiroyuki
    Bayes, Monica
    Bowtell, David D. L.
    Campbell, Peter J.
    Estivill, Xavier
    Grimmond, Sean M.
    Gut, Ivo
    Hirst, Martin
    Lopez-Otin, Carlos
    Majumder, Partha
    Marra, Marco
    Ning, Zemin
    Puente, Xose S.
    Ruan, Yijun
    Stunnenberg, Hendrik G.
    Swerdlow, Harold
    Velculescu, Victor E.
    Wilson, Richard K.
    Xue, Hong H.
    Yang, Liu
    Spellman, Paul T.
    Bader, Gary D.
    Boutros, Paul C.
    Flicek, Paul
    Getz, Gad
    Guigo, Roderic
    Guo, Guangwu
    Haussler, David
    Heath, Simon
    Hubbard, Tim J.
    Jiang, Tao
    Jones, Steven M.
    Li, Qibin
    Lopez-Bigas, Nuria
    Luo, Ruibang
    Pearson, John V.
    Quesada, Victor
    Raphael, Benjamin J.
    Sander, Chris
    Speed, Terence P.
    Stuart, Joshua M.
    Teague, Jon W.
    Totoki, Yasushi
    Tsunoda, Tatsuhiko
    Valencia, Alfonso
    Wheeler, David A.
    Wu, Honglong
    Zhao, Shancen
    Zhou, Guangyu
    Stein, Lincoln D.
    Lathrop, Mark
    Ouellette, B. F. Francis
    Thomas, Gilles
    Yoshida, Teruhiko
    Axton, Myles
    Gunter, Chris
    McPherson, John D.
    Miller, Linda J.
    Kasprzyk, Arek
    Zhang, Junjun
    Haider, Syed A.
    Wang, Jianxin
    Yung, Christina K.
    Cros, Anthony
    Liang, Yong
    Gnaneshan, Saravanamuttu
    Guberman, Jonathan
    Hsu, Jack
    Chalmers, Don R. C.
    Hasel, Karl W.
    Kaan, Terry S. H.
    Knoppers, Bartha M.
    Lowrance, William W.
    Masui, Tohru
    Rodriguez, Laura Lyman
    Vergely, Catherine
    Cloonan, Nicole
    Defazio, Anna
    Eshleman, James R.
    Etemadmoghadam, Dariush
    Gardiner, Brooke B.
    Kench, James G.
    Sutherland, Robert L.
    Tempero, Margaret A.
    Waddell, Nicola J.
    Wilson, Peter J.
    Gallinger, Steve
    Tsao, Ming-Sound
    Shaw, Patricia A.
    Petersen, Gloria M.
    Mukhopadhyay, Debabrata
    DePinho, Ronald A.
    Thayer, Sarah
    Muthuswamy, Lakshmi
    Shazand, Kamran
    Beck, Timothy
    Sam, Michelle
    Timms, Lee
    Ballin, Vanessa
    Ji, Jiafu
    Zhang, Xiuqing
    Chen, Feng
    Hu, Xueda
    Yang, Qi
    Tian, Geng
    Zhang, Lianhai
    Xing, Xiaofang
    Li, Xianghong
    Zhu, Zhenggang
    Yu, Yingyan
    Yu, Jun
    Tost, Joerg
    Brennan, Paul
    Holcatova, Ivana
    Zaridze, David
    Brazma, Alvis
    Egevad, Lars
    Prokhortchouk, Egor
    Banks, Rosamonde Elizabeth
    Uhlén, Mathias
    KTH, Centra, Science for Life Laboratory, SciLifeLab. KTH, Skolan för bioteknologi (BIO), Proteomik (stängd 20130101).
    Viksna, Juris
    Pontén, Fredrik
    Skryabin, Konstantin
    Birney, Ewan
    Borg, Ake
    Borresen-Dale, Anne-Lise
    Caldas, Carlos
    Foekens, John A.
    Martin, Sancha
    Reis-Filho, Jorge S.
    Richardson, Andrea L.
    Sotiriou, Christos
    van't Veer, Laura
    Birnbaum, Daniel
    Blanche, Helene
    Boucher, Pascal
    Boyault, Sandrine
    Masson-Jacquemier, Jocelyne D.
    Pauporte, Iris
    Pivot, Xavier
    Vincent-Salomon, Anne
    Tabone, Eric
    Theillet, Charles
    Treilleux, Isabelle
    Bioulac-Sage, Paulette
    Decaens, Thomas
    Franco, Dominique
    Gut, Marta
    Samuel, Didier
    Zucman-Rossi, Jessica
    Eils, Roland
    Brors, Benedikt
    Korbel, Jan O.
    Korshunov, Andrey
    Landgraf, Pablo
    Lehrach, Hans
    Pfister, Stefan
    Radlwimmer, Bernhard
    Reifenberger, Guido
    Taylor, Michael D.
    von Kalle, Christof
    Majumder, Partha P.
    Pederzoli, Paolo
    Lawlor, Rita T.
    Delledonne, Massimo
    Bardelli, Alberto
    Gress, Thomas
    Klimstra, David
    Zamboni, Giuseppe
    Nakamura, Yusuke
    Miyano, Satoru
    Fujimoto, Akihiro
    Campo, Elias
    de Sanjose, Silvia
    Montserrat, Emili
    Gonzalez-Diaz, Marcos
    Jares, Pedro
    Himmelbauer, Heinz
    Bea, Silvia
    Aparicio, Samuel
    Easton, Douglas F.
    Collins, Francis S.
    Compton, Carolyn C.
    Lander, Eric S.
    Burke, Wylie
    Green, Anthony R.
    Hamilton, Stanley R.
    Kallioniemi, Olli P.
    Ley, Timothy J.
    Liu, Edison T.
    Wainwright, Brandon J.
    International network of cancer genome projects2010Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 464, nr 7291, s. 993-998Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The International Cancer Genome Consortium (ICGC) was launched to coordinate large-scale cancer genome studies in tumours from 50 different cancer types and/or subtypes that are of clinical and societal importance across the globe. Systematic studies of more than 25,000 cancer genomes at the genomic, epigenomic and transcriptomic levels will reveal the repertoire of oncogenic mutations, uncover traces of the mutagenic influences, define clinically relevant subtypes for prognosis and therapeutic management, and enable the development of new cancer therapies.

  • 19. Jun, C.
    et al.
    Ban, Yifang
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geoinformatik.
    Li, S.
    Open access to Earth land-cover map2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 514, nr 7253Artikel i tidskrift (Refereegranskat)
  • 20. Jun, Chen
    et al.
    Ban, Yifang
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Li, Songnian
    China: Open access to Earth land-cover map2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 514, nr 7523, s. 434-434Artikel i tidskrift (Refereegranskat)
  • 21. Kaukua, Nina
    et al.
    Shahidi, Maryam Khatibi
    Konstantinidou, Chrysoula
    Dyachuk, Vyacheslav
    Kaucka, Marketa
    Furlan, Alessandro
    An, Zhengwen
    Wang, Longlong
    Hultman, Isabell
    Ahrlund-Richter, Larsa
    Blom, Hans
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Brismar, Hjalmar
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Cellens fysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Lopes, Natalia Assaife
    Pachnis, Vassilis
    Suter, Ueli
    Clevers, Hans
    Thesleff, Irma
    Sharpe, Paul
    Ernfors, Patrik
    Fried, Kaj
    Adameyko, Igor
    Glial origin of mesenchymal stem cells in a tooth model system2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 513, nr 7519, s. 551-554Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mesenchymal stem cells occupy niches in stromal tissues where they provide sources of cells for specialized mesenchymal derivatives during growth and repair(1). The origins of mesenchymal stem cells have been the subject of considerable discussion, and current consensus holds that perivascular cells form mesenchymal stem cells in most tissues. The continuously growing mouse incisor tooth offers an excellent model to address the origin of mesenchymal stem cells. These stem cells dwell in a niche at the tooth apex where they produce a variety of differentiated derivatives. Cells constituting the tooth are mostly derived from two embryonic sources: neural crest ectomesenchyme and ectodermal epithelium(2). It has been thought for decades that the dental mesenchymal stem cells(3) giving rise to pulp cells and odontoblasts derive from neural crest cells after their migration in the early head and formation of ectomesenchymal tissue(4,5). Here we show that a significant population of mesenchymal stem cells during development, self-renewal and repair of a tooth are derived from peripheral nerve-associated glia. Glial cells generate multipotent mesenchymal stem cells that produce pulp cells and odontoblasts. By combining a clonal colour-coding technique(6) with tracing of peripheral glia, we provide new insights into the dynamics of tooth organogenesis and growth.

  • 22.
    Larsbrink, Johan
    et al.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Rogers, Theresa E.
    Hemsworth, Glyn R.
    McKee, Lauren S.
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Tauzin, Alexandra S.
    Spadiut, Oliver
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap. KTH, Skolan för kemivetenskap (CHE), Centra, Wallenberg Wood Science Center.
    Klinter, Stefan
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Pudlo, Nicholas A.
    Urs, Karthik
    Koropatkin, Nicole M.
    Creagh, A. Louise
    Haynes, Charles A.
    Kelly, Amelia G.
    Nilsson Cederholm, Stefan
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    Davies, Gideon J.
    Martens, Eric C.
    Brumer, Harry
    KTH, Skolan för bioteknologi (BIO), Glykovetenskap.
    A discrete genetic locus confers xyloglucan metabolism in select human gut Bacteroidetes2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 506, nr 7489, s. 498-502Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A well-balanced human diet includes a significant intake of non-starch polysaccharides, collectively termed 'dietary fibre', from the cell walls of diverse fruits and vegetables(1). Owing to the paucity of alimentary enzymes encoded by the human genome(2), our ability to derive energy from dietary fibre depends on the saccharification and fermentation of complex carbohydrates by the massive microbial community residing in our distal gut(3,4). The xyloglucans (XyGs) are a ubiquitous family of highly branched plant cell wall polysaccharides(5,6) whose mechanism(s) of degradation in the human gut and consequent importance in nutrition have been unclear(1,7,8). Here we demonstrate that a single, complex gene locus in Bacteroides ovatus confers XyG catabolism in this common colonic symbiont. Through targeted gene disruption, biochemical analysis of all predicted glycoside hydrolases and carbohydrate-binding proteins, and three-dimensional structural determination of the vanguard endo-xyloglucanase, we reveal the molecular mechanisms through which XyGs are hydrolysed to component monosaccharides for further metabolism. We also observe that orthologous XyG utilization loci (XyGULs) serve as genetic markers of XyG catabolism in Bacteroidetes, that XyGULs are restricted to a limited number of phylogenetically diverse strains, and that XyGULs are ubiquitous in surveyed human metagenomes. Our findings reveal that the metabolism of even highly abundant components of dietary fibre may be mediated by niche species, which has immediate fundamental and practical implications for gut symbiont population ecology in the context of human diet, nutrition and health(9-12).

  • 23.
    Laurell, Fredrik
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Laserfysik.
    Margulis, W.
    Lesche, B.
    Imagingthe χ2 grating in a frequency doubling fibre1995Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687Artikel i tidskrift (Refereegranskat)
  • 24.
    Margulis, Walter
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik. RISE Acreo, Dept Fiber Opt, S-16440 Kista, Sweden..
    Glowing fabrics communicate2018Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 560, nr 7717, s. 170-171Artikel i tidskrift (Övrigt vetenskapligt)
  • 25.
    Marklund, Göran T.
    et al.
    KTH, Tidigare Institutioner                               , Alfvénlaboratoriet.
    Ivchenko, Nickolay V.
    KTH, Tidigare Institutioner                               , Alfvénlaboratoriet.
    Karlsson, Tomas
    KTH, Tidigare Institutioner                               , Alfvénlaboratoriet.
    Fazakerley, A.
    Dunlop, M.
    Lindqvist, Per-Arne
    KTH, Tidigare Institutioner                               , Alfvénlaboratoriet.
    Buchert, S.
    Owen, C.
    Taylor, M.
    Vaivalds, A.
    Carter, P.
    Andre, M.
    Balogh, A.
    Temporal evolution of the electric field accelerating electrons away from the auroral ionosphere2001Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 414, nr 6865, s. 724-727Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The bright night-time aurorae that are visible to the unaided eye are caused by electrons accelerated towards Earth by an upward-pointing electric field(1-3). On adjacent geomagnetic field lines the reverse process occurs: a downward-pointing electric field accelerates electrons away from Earth(4-11). Such magnetic-field-aligned electric fields in the collisionless plasma above the auroral ionosphere have been predicted(12), but how they could be maintained is still a matter for debate(13). The spatial and temporal behaviour of the electric fields-a knowledge of which is crucial to an understanding of their nature-cannot be resolved uniquely by single satellite measurements. Here we report on the first observations by a formation of identically instrumented satellites crossing a beam of upward-accelerated electrons. The structure of the electric potential accelerating the beam grew in magnitude and width for about 200 s, accompanied by a widening of the downward-current sheet, with the total current remaining constant. The 200-s timescale suggests that the evacuation of the electrons from the ionosphere contributes to the formation of the downward-pointing magnetic-field-aligned electric fields. This evolution implies a growing load in the downward leg of the current circuit, which may affect the visible discrete aurorae.

  • 26. Miniati, Francesco
    et al.
    Beresnyak, Andrey
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Self-similar energetics in large clusters of galaxies2015Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 523, nr 7558, s. 59-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Massive galaxy clusters are filled with a hot, turbulent and magnetized intra-cluster medium. Still forming under the action of gravitational instability, they grow in mass by accretion of supersonic flows. These flows partially dissipate into heat through a complex network of large-scale shocks(1), while residual transonic (near-sonic) flows create giant turbulent eddies and cascades(2,3). Turbulence heats the intra-cluster medium(4) and also amplifies magnetic energy by way of dynamo action(5-8). However, the pattern regulating the transformation of gravitational energy into kinetic, thermal, turbulent and magnetic energies remains unknown. Here we report that the energy components of the intra-cluster medium are ordered according to a permanent hierarchy, in which the ratio of thermal to turbulent to magnetic energy densities remains virtually unaltered throughout the cluster's history, despite evolution of each individual component and the drive towards equipartition of the turbulent dynamo. This result revolves around the approximately constant efficiency of turbulence generation from the gravitational energy that is freed during mass accretion, revealed by our computational model of cosmological structure formation(3,9). The permanent character of this hierarchy reflects yet another type of self-similarity in cosmology(10-13), while its structure, consistent with current data(14-18), encodes information about the efficiency of turbulent heating and dynamo action.

  • 27.
    Nerini, Francesco Fuso
    KTH.
    Use SDGs to guide climate action2018Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 557, nr 7703, s. 31-31Artikel i tidskrift (Refereegranskat)
  • 28. Neugebohren, J.
    et al.
    Borodin, D.
    Hahn, H. W.
    Altschäffel, J.
    Kandratsenka, A.
    Auerbach, D. J.
    Campbell, C. T.
    Schwarzer, D.
    Harding, Dan J.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Processteknologi. University of Goettingen, Göttingen, German.
    Wodtke, A. M.
    Kitsopoulos, T. N.
    Velocity-resolved kinetics of site-specific carbon monoxide oxidation on platinum surfaces2018Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 558, nr 7709, s. 280-283Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Catalysts are widely used to increase reaction rates. They function by stabilizing the transition state of the reaction at their active site, where the atomic arrangement ensures favourable interactions 1. However, mechanistic understanding is often limited when catalysts possess multiple active sites - such as sites associated with either the step edges or the close-packed terraces of inorganic nanoparticles 2-4 - with distinct activities that cannot be measured simultaneously. An example is the oxidation of carbon monoxide over platinum surfaces, one of the oldest and best studied heterogeneous reactions. In 1824, this reaction was recognized to be crucial for the function of the Davy safety lamp, and today it is used to optimize combustion, hydrogen production and fuel-cell operation 5,6. The carbon dioxide products are formed in a bimodal kinetic energy distribution 7-13 ; however, despite extensive study 5, it remains unclear whether this reflects the involvement of more than one reaction mechanism occurring at multiple active sites 12,13. Here we show that the reaction rates at different active sites can be measured simultaneously, using molecular beams to controllably introduce reactants and slice ion imaging 14,15 to map the velocity vectors of the product molecules, which reflect the symmetry and the orientation of the active site 16. We use this velocity-resolved kinetics approach to map the oxidation rates of carbon monoxide at step edges and terrace sites on platinum surfaces, and find that the reaction proceeds through two distinct channels 11-13 : it is dominated at low temperatures by the more active step sites, and at high temperatures by the more abundant terrace sites. We expect our approach to be applicable to a wide range of heterogeneous reactions and to provide improved mechanistic understanding of the contribution of different active sites, which should be useful in the design of improved catalysts.

  • 29.
    Newton, Phillip T.
    et al.
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Karolinska Univ Hosp, Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden.;Karolinska Univ Hosp, Pediat Endocrinol Unit, Stockholm, Sweden..
    Li, Lei
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Zhou, Baoyi
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Schweingruber, Christoph
    Karolinska Inst, Dept Neurosci, Stockholm, Sweden..
    Hovorakova, Maria
    Czech Acad Sci, Inst Expt Med, Dept Dev Biol, Prague, Czech Republic..
    Xie, Meng
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Sun, Xiaoyan
    Karolinska Inst, Dept Biosci & Nutr, Huddinge, Sweden.;Karolinska Inst, Ctr Innovat Med, Huddinge, Sweden..
    Sandhow, Lakshmi
    Karolinska Inst, Ctr Hematol & Regenerat Med, Huddinge, Sweden..
    Artemov, Artem V.
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Sechenov First Moscow State Med Univ, Inst Regenerat Med, Moscow, Russia..
    Ivashkin, Evgeny
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Suter, Simon
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Dyachuk, Vyacheslav
    Karolinska Inst, Dept Neurosci, Stockholm, Sweden.;Russian Acad Sci, Far Eastern Branch, Natl Sci Ctr Marine Biol, Vladivostok, Russia..
    El Shahawy, Maha
    Univ Gothenburg, Sahlgrenska Acad, Dept Oral Biochem, Gothenburg, Sweden..
    Gritli-Linde, Amel
    Univ Gothenburg, Sahlgrenska Acad, Dept Oral Biochem, Gothenburg, Sweden..
    Bouderlique, Thibault
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden..
    Petersen, Julian
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Med Univ Vienna, Ctr Brain Res, Dept Mol Neurosci, Vienna, Austria..
    Mollbrink, Annelie
    KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, Centra, Science for Life Laboratory, SciLifeLab. KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Genteknologi.
    Enikolopov, Grigori
    SUNY Stony Brook, Ctr Dev Genet, Stony Brook, NY 11794 USA.;SUNY Stony Brook, Dept Anesthesiol, Stony Brook, NY 11794 USA..
    Qian, Hong
    Karolinska Inst, Ctr Hematol & Regenerat Med, Huddinge, Sweden..
    Fried, Kaj
    Karolinska Inst, Dept Neurosci, Stockholm, Sweden..
    Kasper, Maria
    Karolinska Inst, Dept Biosci & Nutr, Huddinge, Sweden.;Karolinska Inst, Ctr Innovat Med, Huddinge, Sweden..
    Hedlund, Eva
    Karolinska Inst, Dept Neurosci, Stockholm, Sweden..
    Adameyko, Igor
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Med Univ Vienna, Ctr Brain Res, Dept Mol Neurosci, Vienna, Austria..
    Savendahl, Lars
    Karolinska Univ Hosp, Karolinska Inst, Dept Womens & Childrens Hlth, Stockholm, Sweden.;Karolinska Univ Hosp, Pediat Endocrinol Unit, Stockholm, Sweden..
    Chagin, Andrei S.
    Karolinska Inst, Dept Physiol & Pharmacol, Stockholm, Sweden.;Sechenov First Moscow State Med Univ, Inst Regenerat Med, Moscow, Russia..
    A radical switch in clonality reveals a stem cell niche in the epiphyseal growth plate2019Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 567, nr 7747, s. 234-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Longitudinal bone growth in children is sustained by growth plates, narrow discs of cartilage that provide a continuous supply of chondrocytes for endochondral ossification 1 . However, it remains unknown how this supply is maintained throughout childhood growth. Chondroprogenitors in the resting zone are thought to be gradually consumed as they supply cells for longitudinal growth 1,2 , but this model has never been proved. Here, using clonal genetic tracing with multicolour reporters and functional perturbations, we demonstrate that longitudinal growth during the fetal and neonatal periods involves depletion of chondroprogenitors, whereas later in life, coinciding with the formation of the secondary ossification centre, chondroprogenitors acquire the capacity for self-renewal, resulting in the formation of large, stable monoclonal columns of chondrocytes. Simultaneously, chondroprogenitors begin to express stem cell markers and undergo symmetric celldivision. Regulation of the pool of self-renewing progenitors involves the hedgehog and mammalian target of rapamycin complex 1 (mTORC1) signalling pathways. Our findings indicate that a stem cell niche develops postnatally in the epiphyseal growth plate, which provides a continuous supply of chondrocytes over a prolonged period.

  • 30.
    Nilsson, Måns
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    Griggs, D.
    Visbeck, M.
    Erratum: Create a global microbiome effort (Nature (2015) 526 631-634))2016Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 534, nr 7607Artikel i tidskrift (Refereegranskat)
  • 31.
    Nilsson, Måns
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms). Stockholm Environment Institute, Sweden.
    Griggs, Dave
    Visbeck, Martin
    Map the interactions between Sustainable Development Goals2016Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 534, nr 7607, s. 320-322Artikel i tidskrift (Refereegranskat)
  • 32.
    Nystedt, Björn
    et al.
    Stockholm University.
    Vezzi, Francesco
    KTH, Skolan för datavetenskap och kommunikation (CSC), Beräkningsbiologi, CB. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Alekseenko, Andrey
    KTH, Skolan för bioteknologi (BIO), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Sahlin, Kristoffer
    KTH, Skolan för datavetenskap och kommunikation (CSC), Beräkningsbiologi, CB. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Hällman, Jimmie
    KTH, Skolan för bioteknologi (BIO), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Käller, Max
    KTH, Skolan för bioteknologi (BIO), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Rilakovic, Nemanja
    KTH, Skolan för bioteknologi (BIO), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Arvestad, Lars
    KTH, Skolan för datavetenskap och kommunikation (CSC), Beräkningsbiologi, CB. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Lundeberg, Joakim
    KTH, Skolan för bioteknologi (BIO), Genteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    et, al,
    The Norway spruce genome sequence and conifer genome evolution2013Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 497, nr 7451, s. 579-584Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Conifers have dominated forests for more than 200 million years and are of huge ecological and economic importance. Here we present the draft assembly of the 20-gigabase genome of Norway spruce (Picea abies), the first available for any gymnosperm. The number of well-supported genes (28,354) is similar to the >100 times smaller genome of Arabidopsis thaliana, and there is no evidence of a recent whole-genome duplication in the gymnosperm lineage. Instead, the large genome size seems to result from the slow and steady accumulation of a diverse set of long-terminal repeat transposable elements, possibly owing to the lack of an efficient elimination mechanism. Comparative sequencing of Pinus sylvestris, Abies sibirica, Juniperus communis, Taxus baccata and Gnetum gnemon reveals that the transposable element diversity is shared among extant conifers. Expression of 24-nucleotide small RNAs, previously implicated in transposable element silencing, is tissue-specific and much lower than in other plants. We further identify numerous long (>10,000 base pairs) introns, gene-like fragments, uncharacterized long non-coding RNAs and short RNAs. This opens up new genomic avenues for conifer forestry and breeding.

  • 33.
    Ohlsson, Tommy
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Teoretisk partikelfysik.
    Another collider is not the way forward2013Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 494, nr 7435, s. 35-35Artikel i tidskrift (Övrigt vetenskapligt)
  • 34.
    Ohlsson, Tommy
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Teoretisk partikelfysik.
    Don't let furore over neutrinos blur results2012Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 485, nr 7398, s. 309-309Artikel i tidskrift (Refereegranskat)
  • 35.
    Ohlsson, Tommy
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Teoretisk partikelfysik.
    International Linear Collider: Another collider is not the way forward2013Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 494, nr 7435Artikel i tidskrift (Refereegranskat)
  • 36.
    Ohlsson, Tommy
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Teoretisk partikelfysik.
    Preprint servers: Follow arXiv's lead2012Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 489, nr 7416, s. 367-Artikel i tidskrift (Refereegranskat)
  • 37.
    Olson, Jonas
    KTH, Skolan för elektro- och systemteknik (EES), Rymd- och plasmafysik.
    The magnetospheric clock of Saturn: a self-organized plasma dynamoIngår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687Artikel i tidskrift (Övrigt vetenskapligt)
  • 38. Percec, V.
    et al.
    Dulcey, A. E.
    Balagurusamy, V. S. K.
    Miura, Y.
    Smidrkal, J.
    Peterca, M.
    Nummelin, S.
    Edlund, Ulrica
    KTH, Tidigare Institutioner                               , Polymerteknologi.
    Hudson, S. D.
    Heiney, P. A.
    Hu, D. A.
    Magonov, S. N.
    Vinogradov, S. A.
    Self-assembly of amphiphilic dendritic dipeptides into helical pores2004Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 430, nr 7001, s. 764-768Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Natural pore-forming proteins act as viral helical coats(1) and transmembrane channels(2-4), exhibit antibacterial activity(5) and are used in synthetic systems, such as for reversible encapsulation(6) or stochastic sensing(7). These diverse functions are intimately linked to protein structure(1-4). The close link between protein structure and protein function makes the design of synthetic mimics a formidable challenge, given that structure formation needs to be carefully controlled on all hierarchy levels, in solution and in the bulk. In fact, with few exceptions(8,9), synthetic pore structures capable of assembling into periodically ordered assemblies that are stable in solution and in the solid state(10-13) have not yet been realized. In the case of dendrimers, covalent(14) and non- covalent(15) coating and assembly of a range of different structures(15-17) has only yielded closed columns(18). Here we describe a library of amphiphilic dendritic dipeptides that self-assemble in solution and in bulk through a complex recognition process into helical pores. We find that the molecular recognition and self-assembly process is sufficiently robust to tolerate a range of modifications to the amphiphile structure, while preliminary proton transport measurements establish that the pores are functional. We expect that this class of self-assembling dendrimers will allow the design of a variety of biologically inspired systems with functional properties arising from their porous structure.

  • 39.
    Phan, T. D.
    et al.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Eastwood, J. P.
    Imperial Coll London, Blackett Lab, London, England..
    Shay, M. A.
    Univ Delaware, Newark, DE USA..
    Drake, J. F.
    Univ Maryland, College Pk, MD 20742 USA..
    Sonnerup, B. U. O.
    Dartmouth Coll, Hanover, NH 03755 USA..
    Fujimoto, M.
    JAXA, ISAS, Sagamihara, Kanagawa, Japan..
    Cassak, P. A.
    West Virginia Univ, Morgantown, WV USA..
    Oieroset, M.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Burch, J. L.
    Southwest Res Inst, San Antonio, TX USA..
    Torbert, R. B.
    Univ New Hampshire, Durham, NH 03824 USA..
    Rager, A. C.
    Catholic Univ Amer, Washington, DC 20064 USA.;NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Dorelli, J. C.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Gershman, D. J.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Pollock, C.
    Denali Sci, Healy, AK USA..
    Pyakurel, P. S.
    Univ Delaware, Newark, DE USA..
    Haggerty, C. C.
    Univ Delaware, Newark, DE USA..
    Khotyaintsev, Y.
    Swedish Inst Space Phys, Uppsala, Sweden..
    Lavraud, B.
    Univ Toulouse, Inst Rech Astrophys & Planetol, Toulouse, France..
    Saito, Y.
    JAXA, ISAS, Sagamihara, Kanagawa, Japan..
    Oka, M.
    Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA..
    Ergun, R. E.
    Univ Colorado, LASP, Boulder, CO 80309 USA..
    Retino, A.
    Ecole Polytech, CNRS, Paris, France..
    Le Contel, O.
    Ecole Polytech, CNRS, Paris, France..
    Argall, M. R.
    Univ New Hampshire, Durham, NH 03824 USA..
    Giles, B. L.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Moore, T. E.
    NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
    Wilder, F. D.
    Univ Colorado, LASP, Boulder, CO 80309 USA..
    Strangeway, R. J.
    Univ Calif Los Angeles, Los Angeles, CA USA..
    Russell, C. T.
    Univ Calif Los Angeles, Los Angeles, CA USA..
    Lindqvist, Per-Arne
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Rymd- och plasmafysik.
    Magnes, W.
    Austrian Acad Sci, Space Res Inst, Graz, Austria..
    Electron magnetic reconnection without ion coupling in Earth's turbulent magnetosheath2018Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 557, nr 7704, s. 202-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Magnetic reconnection in current sheets is a magnetic-to-particle energy conversion process that is fundamental to many space and laboratory plasma systems. In the standard model of reconnection, this process occurs in a minuscule electron-scale diffusion region(1,2). On larger scales, ions couple to the newly reconnected magnetic-field lines and are ejected away from the diffusion region in the form of bi-directional ion jets at the ion Alfven speed(3-5). Much of the energy conversion occurs in spatially extended ion exhausts downstream of the diffusion region(6). In turbulent plasmas, which contain a large number of small-scale current sheets, reconnection has long been suggested to have a major role in the dissipation of turbulent energy at kinetic scales(7-11). However, evidence for reconnection plasma jetting in small-scale turbulent plasmas has so far been lacking. Here we report observations made in Earth's turbulent magnetosheath region (downstream of the bow shock) of an electron-scale current sheet in which diverging bi-directional super-ion-Alfvenic electron jets, parallel electric fields and enhanced magnetic-to-particle energy conversion were detected. Contrary to the standard model of reconnection, the thin reconnecting current sheet was not embedded in a wider ion-scale current layer and no ion jets were detected. Observations of this and other similar, but unidirectional, electron jet events without signatures of ion reconnection reveal a form of reconnection that can drive turbulent energy transfer and dissipation in electron-scale current sheets without ion coupling.

  • 40. Rockstrom, Johan
    et al.
    Steffen, Will
    Noone, Kevin
    Persson, Asa
    Chapin, F. Stuart, III
    Lambin, Eric F.
    Lenton, Timothy M.
    Scheffer, Marten
    Folke, Carl
    Schellnhuber, Hans Joachim
    Nykvist, Bjorn
    de Wit, Cynthia A.
    Hughes, Terry
    van der Leeuw, Sander
    Rodhe, Henning
    Sörlin, Sverker
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Teknik- och vetenskapshistoria.
    Snyder, Peter K.
    Costanza, Robert
    Svedin, Uno
    Falkenmark, Malin
    Karlberg, Louise
    Corell, Robert W.
    Fabry, Victoria J.
    Hansen, James
    Walker, Brian
    Liverman, Diana
    Richardson, Katherine
    Crutzen, Paul
    Foley, Jonathan A.
    A safe operating space for humanity2009Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 461, nr 7263, s. 472-475Artikel i tidskrift (Refereegranskat)
  • 41.
    Sörlin, Sverker
    Filosofi och historia, KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Filosofi och teknikhistoria, Historiska studier av teknik, vetenskap och miljö. KTH Royal Inst Technol, Div Hist Sci Technol & Environm, Stockholm, Sweden..
    Floating Coast: An Environmental History of the Bering Strait2019Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 572, nr 7768, s. 176-177Artikel, recension (Övrigt vetenskapligt)
  • 42. Taga, A.
    et al.
    Nordstrom, L.
    James, P.
    Johansson, Börje
    Eriksson, O.
    Non-collinear states in magnetic sensors2000Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 406, nr 6793, s. 280-282Artikel i tidskrift (Refereegranskat)
  • 43. Tong, L. M.
    et al.
    Gattass, R. R.
    Ashcom, J. B.
    He, Sailing
    Lou, J. Y.
    Shen, M. Y.
    Maxwell, I.
    Mazur, E.
    Subwavelength-diameter silica wires for low-loss optical wave guiding2003Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 426, nr 6968, s. 816-819Artikel i tidskrift (Refereegranskat)
  • 44. Uhlen, P.
    et al.
    Laestadius, A.
    Jahnukainen, T.
    Soderblom, T.
    Backhed, F.
    Celsi, G.
    Brismar, Hjalmar
    Normark, S.
    Aperia, A.
    Richter-Dahlfors, A.
    alpha-Haemolysin of uropathogenic E-coli induces Ca2+ oscillations in renal epithelial cells2000Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 405, nr 6787, s. 694-697Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pyelonephritis is one of the most common febrile diseases in children. If not treated appropriately, it causes irreversible renal damage and accounts for a large proportion of end stage renal failures(1). Renal scarring can occur in the absence of inflammatory cells, indicating that bacteria may have a direct signalling effect on renal cells(2). Intracellular calcium ([Ca2+](i)) oscillations can protect cells from the cytotoxic effects of prolonged increases in intracellular calcium(3,4). However, no pathophysiologically relevant protein that induces such oscillations has been identified. Here we show that infection by uropathogenic Escherichia coli induces a constant, low-frequency oscillatory [Ca2+](i) response in target primary rat renal epithelial cells induced by the secreted RTX (repeats-in-toxin) toxin alpha-haemolysin. The response depends on calcium influx through L-type calcium channels as well as from internal stores gated by inositol triphosphate. Internal calcium oscillations induced by alpha-haemolysin in a renal epithelial cell line stimulated production of cytokines interleukin (IL)-6 and IL-8. Our findings indicate a novel role for alpha-haemolysin in pyelonephritis: as an inducer of an oscillating second messenger response in target cells, which fine-tunes gene expression during the inflammatory response.

  • 45. Wang, Kaituo
    et al.
    Sitsel, Oleg
    Meloni, Gabriele
    Autzen, Henriette Elisabeth
    Andersson, Magnus
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Beräkningsbiofysik. KTH, Centra, Science for Life Laboratory, SciLifeLab.
    Klymchuk, Tetyana
    Nielsen, Anna Marie
    Rees, Douglas C.
    Nissen, Poul
    Gourdon, Pontus
    Structure and mechanism of Zn2+-transporting P-type ATPases2014Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 514, nr 7523, s. 518-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Zinc is an essential micronutrient for all living organisms. It is required for signalling and proper functioning of a range of proteins involved in, for example, DNA binding and enzymatic catalysis(1). In prokaryotes and photosynthetic eukaryotes, Zn2+-transporting P-type ATPases of class IB (ZntA) are crucial for cellular redistribution and detoxification of Zn2+ and related elements(2,3). Here we present crystal structures representing the phosphoenzyme ground state (E2P) and a dephosphorylation intermediate (E2.P-i) of ZntA from Shigella sonnei, determined at 3.2 angstrom and 2.7 angstrom resolution, respectively. The structures reveal a similar fold to Cu+-ATPases, with an amphipathic helix at the membrane interface. A conserved electronegative funnel connects this region to the intramembranous high-affinity ion-binding site and may promote specific uptake of cellular Zn2+ ions by the transporter. The E2P structure displays a wide extracellular release pathway reaching the invariant residues at the high-affinity site, including C392, C394 and D714. The pathway closes in the E2.P-i state, in which D714 interacts with the conserved residue K693, which possibly stimulates Zn2+ release as a built-in counter ion, as has been proposed for H+-ATPases. Indeed, transport studies in liposomes provide experimental support for ZntA activity without counter transport. These findings suggest a mechanistic link between P-IB-type Zn2+-ATPases and P-III-type H+-ATPases and at the same time show structural features of the extracellular release pathway that resemble P-II-type ATPases such as the sarcoplasmic/endoplasmic reticulum Ca2+-ATPase(4,5) (SERCA) and Na+, K+-ATPase(6). These findings considerably increase our understanding of zinc transport in cells and represent new possibilities for biotechnology and biomedicine.

  • 46.
    Wildermuth, Stephan
    et al.
    Physikalisches Institut, Universität Heidelberg.
    Hofferberth, Sebastian
    Physikalisches Institut, Universität Heidelberg.
    Lesanovsky, Igor
    Physikalisches Institut, Universität Heidelberg.
    Haller, Elmar
    Physikalisches Institut, Universität Heidelberg.
    Andersson, L. Mauritz
    Physikalisches Institut, Universität Heidelberg.
    Groth, Sönke
    Physikalisches Institut, Universität Heidelberg.
    Bar-Joseph, Israel
    Department of Condensed Matter Physics, The Weizmann Institute of Science.
    Krüger, Peter
    Physikalisches Institut, Universität Heidelberg.
    Schmiedmayer, Jörg
    Physikalisches Institut, Universität Heidelberg.
    Bose-Einstein condensates: Microscopic magnetic-field imaging2005Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 435, nr 7041, s. 440-Artikel i tidskrift (Övrigt vetenskapligt)
  • 47.
    Xiang, Jinbao
    et al.
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA.;Jilin Univ, Sch Pharmaceut Sci, Ctr Combinatorial Chem & Drug Discovery, Jilin, Jilin, Peoples R China..
    Shang, Ming
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Kawamata, Yu
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Lundberg, Helena
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemi, Organisk kemi. Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Reisberg, Solomon H.
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Chen, Miao
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Mykhailiuk, Pavel
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA.;Enamine Ltd, Kiev, Ukraine.;Taras Shevchenko Natl Univ Kyiv, Chem Dept, Kiev, Ukraine..
    Beutner, Gregory
    Bristol Myers Squibb, Chem & Synthet Dev, New Brunswick, NJ USA..
    Collins, Michael R.
    Pfizer Inc, Dept Chem, La Jolla Labs, San Diego, CA USA..
    Davies, Alyn
    Pfizer Med Sci, Groton, CT USA..
    Del Bel, Matthew
    Pfizer Inc, Dept Chem, La Jolla Labs, San Diego, CA USA..
    Gallego, Gary M.
    Pfizer Inc, Dept Chem, La Jolla Labs, San Diego, CA USA..
    Spangler, Jillian E.
    Pfizer Inc, Dept Chem, La Jolla Labs, San Diego, CA USA..
    Starr, Jeremy
    Pfizer Med Sci, Groton, CT USA..
    Yang, Shouliang
    Pfizer Inc, Dept Chem, La Jolla Labs, San Diego, CA USA..
    Blackmond, Donna G.
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Baran, Phil S.
    Scripps Res, Dept Chem, La Jolla, CA 92037 USA..
    Hindered dialkyl ether synthesis with electrogenerated carbocations2019Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 573, nr 7774, s. 398-+Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Hindered ethers are of high value for various applications; however, they remain an underexplored area of chemical space because they are difficult to synthesize via conventional reactions(1,2). Such motifs are highly coveted in medicinal chemistry, because extensive substitution about the ether bond prevents unwanted metabolic processes that can lead to rapid degradation in vivo. Here we report a simple route towards the synthesis of hindered ethers, in which electrochemical oxidation is used to liberate high-energy carbocations from simple carboxylic acids. These reactive carbocation intermediates, which are generated with low electrochemical potentials, capture an alcohol donor under non-acidic conditions; this enables the formation of a range of ethers (more than 80 have been prepared here) that would otherwise be difficult to access. The carbocations can also be intercepted by simple nucleophiles, leading to the formation of hindered alcohols and even alkyl fluorides. This method was evaluated for its ability to circumvent the synthetic bottlenecks encountered in the preparation of 12 chemical scaffolds, leading to higher yields of the required products, in addition to substantial reductions in the number of steps and the amount of labour required to prepare them. The use of molecular probes and the results of kinetic studies support the proposed mechanism and the role of additives under the conditions examined. The reaction manifold that we report here demonstrates the power of electrochemistry to access highly reactive intermediates under mild conditions and, in turn, the substantial improvements in efficiency that can be achieved with these otherwise-inaccessible intermediates.

  • 48.
    Yu, ChaoQing
    et al.
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China.;Cross Strait Tsinghua Res Inst, AI Earth Lab, Xiamen, Peoples R China..
    Huang, Xiao
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China.;Norwegian Inst Bioecon Res, Saerheim, Norway..
    Chen, Han
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Godfray, H. Charles J.
    Univ Oxford, Dept Zool, Oxford, England.;Univ Oxford, Oxford Martin Sch, Oxford, England..
    Wright, Jonathon S.
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Hall, Jim W.
    Univ Oxford, Environm Change Inst, Oxford, England..
    Gong, Peng
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China.;Cross Strait Tsinghua Res Inst, AI Earth Lab, Xiamen, Peoples R China..
    Ni, ShaoQiang
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Qiao, ShengChao
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Huang, GuoRui
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Xiao, YuChen
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Zhang, Jie
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Feng, Zhao
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Ju, XiaoTang
    China Agr Univ, Coll Resources & Environm Sci, Beijing, Peoples R China..
    Ciais, Philippe
    LSCE, Gif Sur Yvette, France..
    Stenseth, Nils Chr.
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China.;Univ Oslo, CEES, Oslo, Norway..
    Hessen, Dag O.
    Univ Oslo, Sect Aquat Biol & Toxicol AQUA, Oslo, Norway..
    Sun, ZhanLi
    Leibniz Inst Agr Dev Transit Econ IAMO, Halle, Saale, Germany..
    Yu, Le
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Cai, WenJia
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Fu, HaoHuan
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Huang, XiaoMeng
    Tsinghua Univ, Dept Earth Syst Sci, Minist Educ, Key Lab Earth Syst Modeling, Beijing, Peoples R China..
    Zhang, Chi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH).
    Liu, HongBin
    Chinese Acad Agr Sci, Inst Agr Resources & Reg Planning, Beijing, Peoples R China..
    Taylor, James
    Newcastle Univ, Sch Nat & Environm Sci, Newcastle, England..
    Managing nitrogen to restore water quality in China2019Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 567, nr 7749, s. 516-520Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The nitrogen cycle has been radically changed by human activities(1). China consumes nearly one third of the world's nitrogen fertilizers. The excessive application of fertilizers(2,3) and increased nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen 'boundary'(4) in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 +/- 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated 'safe' nitrogen discharge threshold (5.2 +/- 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 +/- 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 +/- 0.3 megatonnes of nitrogen per year-about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18-29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services.

  • 49. Zhang, R.
    et al.
    Zhang, Y.
    Dong, Z. C.
    Jiang, S.
    Zhang, C.
    Chen, L. G.
    Zhang, L.
    Liao, Y.
    Aizpurua, J.
    Luo, Yi
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Yang, J. L.
    Hou, J. G.
    Chemical mapping of a single molecule by plasmon-enhanced Raman scattering2013Ingår i: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 498, nr 7452, s. 82-86Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Visualizing individual molecules with chemical recognition is a longstanding target in catalysis, molecular nanotechnology and biotechnology. Molecular vibrations provide a valuable 'finger-print' for such identification. Vibrational spectroscopy based on tip-enhanced Raman scattering allows us to access the spectral signals of molecular species very efficiently via the strong localized plasmonic fields produced at the tip apex(1-11). However, the best spatial resolution of the tip-enhanced Raman scattering imaging is still limited to 3-15 nanometres(5,12-16), which is not adequate for resolving a single molecule chemically. Here we demonstrate Raman spectral imaging with spatial resolution below one nanometre, resolving the inner structure and surface configuration of a single molecule. This is achieved by spectrally matching the resonance of the nanocavity plasmon to the molecular vibronic transitions, particularly the downward transition responsible for the emission of Raman photons. This matching is made possible by the extremely precise tuning capability provided by scanning tunnelling microscopy. Experimental evidence suggests that the highly confined and broadband nature of the nanocavity plasmon field in the tunnelling gap is essential for ultrahigh-resolution imaging through the generation of an efficient double-resonance enhancement for both Raman excitation and Raman emission. Our technique not only allows for chemical imaging at the single-molecule level, but also offers a new way to study the optical processes and photochemistry of a single molecule.

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