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Katayama S, Pradere B, Grossmann N, Potretzke A, Boorjian S, Daneshmand S, Djaladat H, Sfakianos J, Mari A, Khene Z, D’Andrea D, Kikuchi E, Fujita K, Heindenreich A, Raman J, Roumiguié M, Abdollah F, Marcus J, Breda A, Fontana M, Rouprêt M, Araki M, Nasu Y, Shariat S. Clinical significance of tumor location for ureteroscopic tumor grading in upper tract urothelial carcinoma. Eur Urol 2022. [DOI: 10.1016/s0302-2838(22)00383-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Reni M, Braverman J, Hendifar A, Li CP, Macarulla Mercade T, Oh DY, Riess H, Tempero M, Lu B, Marcus J, Joshi N, Botterman M, Dueck A. Evaluation of minimal important difference (MID) for the European organisation for research and treatment of cancer (EORTC) pancreatic cancer module (PAN26) in patients with surgically resected pancreatic adenocarcinoma. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz247.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yurcheshen M, Marsella J, Nguyen K, Marcus J, Marcus C, Dorsey E, Pigeon W. 1066 Interrater Reliability in Telemedicine vs. In-person Evaluations for Obstructive Sleep Apnea. Sleep 2018. [DOI: 10.1093/sleep/zsy061.1065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- M Yurcheshen
- University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - J Marsella
- University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - K Nguyen
- Saddleback Memorial Hospital, Los Angeles, CA
| | - J Marcus
- University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - C Marcus
- University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - E Dorsey
- University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - W Pigeon
- University of Rochester School of Medicine and Dentistry, Rochester, NY
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Koperski M, Nogajewski K, Arora A, Cherkez V, Mallet P, Veuillen JY, Marcus J, Kossacki P, Potemski M. Single photon emitters in exfoliated WSe2 structures. Nat Nanotechnol 2015; 10:503-6. [PMID: 25938573 DOI: 10.1038/nnano.2015.67] [Citation(s) in RCA: 304] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 03/12/2015] [Indexed: 05/20/2023]
Abstract
Crystal structure imperfections in solids often act as efficient carrier trapping centres, which, when suitably isolated, act as sources of single photon emission. The best known examples of such attractive imperfections are well-width or composition fluctuations in semiconductor heterostructures (resulting in the formation of quantum dots) and coloured centres in wide-bandgap materials such as diamond. In the recently investigated thin films of layered compounds, the crystal imperfections may logically be expected to appear at the edges of commonly investigated few-layer flakes of these materials exfoliated on alien substrates. Here, we report comprehensive optical micro-spectroscopy studies of thin layers of tungsten diselenide (WSe2), a representative semiconducting dichalcogenide with a bandgap in the visible spectral range. At the edges of WSe2 flakes (transferred onto Si/SiO2 substrates) we discover centres that, at low temperatures, give rise to sharp emission lines (100 μeV linewidth). These narrow emission lines reveal the effect of photon antibunching, the unambiguous attribute of single photon emitters. The optical response of these emitters is inherently linked to the two-dimensional properties of the WSe2 monolayer, as they both give rise to luminescence in the same energy range, have nearly identical excitation spectra and have very similar, characteristically large Zeeman effects. With advances in the structural control of edge imperfections, thin films of WSe2 may provide added functionalities that are relevant for the domain of quantum optoelectronics.
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Affiliation(s)
- M Koperski
- 1] Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25 Rue des Martyrs, Grenoble 38042, France [2] Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - K Nogajewski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25 Rue des Martyrs, Grenoble 38042, France
| | - A Arora
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25 Rue des Martyrs, Grenoble 38042, France
| | - V Cherkez
- Institut Néel, CNRS-UGA, Grenoble 38042, France
| | - P Mallet
- Institut Néel, CNRS-UGA, Grenoble 38042, France
| | | | - J Marcus
- Institut Néel, CNRS-UGA, Grenoble 38042, France
| | - P Kossacki
- 1] Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25 Rue des Martyrs, Grenoble 38042, France [2] Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw 02-093, Poland
| | - M Potemski
- Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, 25 Rue des Martyrs, Grenoble 38042, France
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Marcus J, Touraud D, Prévost S, Diat O, Zemb T, Kunz W. Influence of additives on the structure of surfactant-free microemulsions. Phys Chem Chem Phys 2015; 17:32528-38. [DOI: 10.1039/c5cp06364g] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In surfactant-free microemulsions, the combination ethanol/antagonistic salt behaves like a surfactant.
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Affiliation(s)
- J. Marcus
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - D. Touraud
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
| | - S. Prévost
- ESRF
- The European Synchrotron
- 38000 Grenoble
- France
| | - O. Diat
- Institut de Chimie Séparative de Marcoule
- UMR 5257 (CEA/CNRS/UM/ENSCM)
- 30207 Bagnols sur Cèze
- France
| | - T. Zemb
- Institut de Chimie Séparative de Marcoule
- UMR 5257 (CEA/CNRS/UM/ENSCM)
- 30207 Bagnols sur Cèze
- France
| | - W. Kunz
- Institute of Physical and Theoretical Chemistry
- University of Regensburg
- 93040 Regensburg
- Germany
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Grayson DK, Meltzer DJ, Buikstra JE, Flannery KV, Fowler CS, Marcus J, O'Connell JF, Piperno DR, Sabloff JA, Smith BD, Thomas DH, Willerslev E, Zeder MA. Early Americans: respecting ancestors. Science 2014; 345:390. [PMID: 25061197 DOI: 10.1126/science.345.6195.390-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- D K Grayson
- Department of Anthropology and Quaternary Research Center, University of Washington, Seattle, WA 98185, USA.
| | - D J Meltzer
- Department of Anthropology, Southern Methodist University, Dallas, TX 75275, USA
| | - J E Buikstra
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287, USA
| | - K V Flannery
- Museum of Anthropological Archaeology, University of Michigan, Ann Arbor, MI 48109, USA
| | - C S Fowler
- Department of Anthropology, University of Nevada, Reno, NV 89557, USA
| | - J Marcus
- Museum of Anthropological Archaeology, University of Michigan, Ann Arbor, MI 48109, USA
| | - J F O'Connell
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
| | - D R Piperno
- Program in Human Ecology and Archaeobiology and Smithsonian Tropical Research Institute (Panama), National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | | | - B D Smith
- Program in Human Ecology and Archaeobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
| | - D H Thomas
- Division of Anthropology, American Museum of Natural History, New York, NY 10024, USA
| | - E Willerslev
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, DK-1350 Copenhagen K, Denmark
| | - M A Zeder
- Program in Human Ecology and Archaeobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560, USA
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Schöttl S, Marcus J, Diat O, Touraud D, Kunz W, Zemb T, Horinek D. Emergence of surfactant-free micelles from ternary solutions. Chem Sci 2014. [DOI: 10.1039/c4sc00153b] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Hilz M, Koehn J, Ammon F, Marcus J, Flanagan S, De Fina P, Baltadzhieva R, Schwab S, Moeller S. Valsalva maneuver shows prolonged sympathetic outflow in patients with a history of mild traumatic brain injury. J Neurol Sci 2013. [DOI: 10.1016/j.jns.2013.07.2378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Toulemonde P, Santos-Cottin D, Lepoittevin C, Strobel P, Marcus J. Dependence of the structural, transport and magnetic properties of Tl(1-y)Fe(2-z)(Se(1-x)S(x))2 with isovalent substitution of Se by S. J Phys Condens Matter 2013; 25:075703. [PMID: 23343616 DOI: 10.1088/0953-8984/25/7/075703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The effect of selenium substitution by sulfur in the Tl(1-y)Fe(2-z)Se(2) antiferromagnet was studied by x-ray and electron diffraction, magnetization and transport measurements. Tl(0.8)Fe(1.5)(Se(1-x)S(x))(2) (nominal composition) solid solution was synthesized in the full x range (0 ≤ x(S) ≤ 1) using the sealed tube technique. No superconductivity was found down to 4.2 K in the series despite the fact that the optimal crystallographic parameters, determined by Rietveld refinements, are reached in the series (i.e. the Fe-(Se, S) interplane height and (Se, S)-Fe-(Se, S) angle for which the critical superconducting transition T(c) is usually maximal in pnictides). A quasi-full Tl site (y ~ 0.05) compared to significant alkaline deficiency (y = 0.2-0.3) in analogous A(1-y)Fe(2-z)Se(2) (A = K, Rb, Cs), and the resulting differences in iron valency, density of states and doping, are suggested as an explanation for this absence of superconductivity. Transmission electron microscopy confirmed the existence of an ordered iron vacancies network in the samples of the Tl(0.8)Fe(1.5)(Se(1-x)S(x))(2) series in the form of the tetragonal √5a × √5a × c superstructure (I4/m). The Néel temperature (T(N)) indicating the onset of antiferromagnetism order in this √5a × √5a × c supercell is found to decrease from 450 K in the selenide (x = 0) to 330 K in the sulfide (x = 1). Finally, we demonstrate a direct linear relationship between T(N) and the Fe-(Se, S) bond length (or Fe-(Se, S) height).
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Affiliation(s)
- P Toulemonde
- Institut Néel, CNRS and Université Joseph Fourier, 25 avenue des Martyrs, BP 166, F-38042 Grenoble cedex 9, France.
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Park J, Marcus J, Bernstein K, Pandori M, Snell A, Philip S. P1-S2.41 Sentinel survillance for pharyngeal chlamydia and gonorrhoea among men who have sex with men - San Francisco, 2010. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.98] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bernstein K, Hjord H, Marcus J, Kohn R, Philip S. P1-S5.08 Attendance at local and national sex-events associated with STD diagnosis, San Francisco, 2010. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bernstein K, Goldring S, Marcus J, Philip S. O2-S3.06 Area-based socioeconomic measures associated with female chlamydia and gonorrhoea, San Francisco, 2009. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050109.84] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Gift T, Bernstein K, Chesson H, Marcus J, Pipkin S, Kent C. P2-S6.11 The cost-effectiveness of screening men who have sex with men for rectal chlamydial and gonococcal infection to prevent HIV infection. Br J Vener Dis 2011. [DOI: 10.1136/sextrans-2011-050108.363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Noat Y, Cren T, Dubost V, Lange S, Debontridder F, Toulemonde P, Marcus J, Sulpice A, Sacks W, Roditchev D. Disorder effects in pnictides: a tunneling spectroscopy study. J Phys Condens Matter 2010; 22:465701. [PMID: 21403373 DOI: 10.1088/0953-8984/22/46/465701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present the synthesis and the tunneling spectroscopy study of superconducting FeSe(0.5)Te(0.5) (T(c) = 14 K), SmFeAsO(0.85) (T(c) = 54 K) and SmFeAsO(0.9)F(0.1) (T(c) = 45 K). The samples were characterized by Rietveld refinement of x-ray diffraction patterns and transport as well as temperature-dependent magnetic measurements. Tunneling experiments on FeSe(0.5)Te(0.5) revealed a single superconducting gap ∼ 1 meV in BCS-like tunneling conductance spectra. In SmFeAsO(0.85) and SmFeAsO(0.9)F(0.1), however, more complex spectra were observed, characterized by two gap-like structures at ∼ 4 and ∼ 10 meV. These spectra are qualitatively understood assuming a two-band superconductor with a 's ±' order parameter. We show that, depending on the sign relation between the pairing amplitudes in the two bands, the interband quasiparticle scattering has a crucial effect on the shape of the tunneling spectra. On the other hand, single-gap spectra found in FeSe(0.5)Te(0.5) are more compatible with a disorder-induced 's '-wave gap, due to the Se-Te substitution.
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Affiliation(s)
- Y Noat
- Institut des Nanosciences de Paris, CNRS UMR 7588, Université Pierre et Marie Curie Paris 6, Paris, France.
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Parsons A, Shapiro D, Miller C, Marcus J, Harris M, Herbst S, Roseff S, Graham H. FemVue Sono Tubal Evaluation System for Selective Sonohysterosalpingography in the Office Setting. J Minim Invasive Gynecol 2010. [DOI: 10.1016/j.jmig.2010.08.286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Parsons A, Shapiro D, Miller C, Marcus J, Harris M, Roseff S. FemVue™ Sono Tubal Evalution System for selective sonohysterosalpingography in the office setting. Fertil Steril 2010. [DOI: 10.1016/j.fertnstert.2010.07.303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Thus far I have discussed ancient Maya sociopolitical structure from the upper levels of the hierarchy downward. Let me now summarize their territorial organization from the bottom upward, starting at the hamlet level (Fig. 8). The smallest unit of settlement-one usually overlooked by archeological surveys in the lowland rain forest-was probably a cluster of thatched huts occupied by a group of related families; larger clusters may have been divided into four quadrants along the lines suggested by Coe (26). Because of the long fallow period (6 to 8 years) characteristic of slash-and-burn agriculture in the Petén, these small hamlets are presumed to have changed location over the years, although they probably shifted in a somewhat circular fashion around a tertiary ceremonial-civic center for whose maintenance they were partly responsible. These tertiary centers were spaced at fairly regular intervals around secondary ceremonial-civic centers with pyramids, carved monuments, and palace-like residences. In turn, the secondary centers occurred at such regular intervals as to form hexagonal patterns around primary centers, which were still larger, with acropolises, multiple ceremonial plazas, and greater numbers of monuments. In some cases, the distance between secondary centers was roughly twice the distance between secondary and tertiary centers, creating a lattice of nested hexagonal cells. This pattern, which conforms to a Western theoretical construct, was presumably caused by factors of service function, travel, and transport. The pattern was not recognized by the Maya at all. They simply recognized that a whole series of smaller centers were dependent on a primary center and therefore mentioned its emblem glyph. Linking the centers of the various hexagons were marriage alliances between members of royal dynasties, who had no kinship ties with the farmers in the hamlets. Out of the large number of primary centers available to them, the Maya selected four as regional capitals. True to their cosmology, the Maya regarded these capitals as associated with the four quadrants of their realm, regardless of their actual location. Each was the home city for a very important dynasty whose junior members probably ruled secondary centers. Since the hexagonal lattices were probably adjusted to variations in population density, each of the four quadrants of the Maya realm probably controlled a comparable number of persons. So strong was the cognized model that, despite the rise and fall of individual centers, there seem always to have been four capitals, each associated with a direction and, presumably, with a color. There is still a great deal to learn about the social, political, and territorial organization of the lowland Maya, and parts of the picture presented here need far more data for their confirmation. What seems likely is that the Maya had an overall quadripartite organization (rather than a core and buffer zone) and that within each quadrant there was at least a five-tiered administrative hierarchy of capital, secondary center, tertiary center, village, and hamlet. Perhaps most significant, there was no real conflict between the lattice-like network predicted by locational analysis and the cosmological four-part structure predicted by epigraphy and ethnology.
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Gleick PH, Adams RM, Amasino RM, Anders E, Anderson DJ, Anderson WW, Anselin LE, Arroyo MK, Asfaw B, Ayala FJ, Bax A, Bebbington AJ, Bell G, Bennett MVL, Bennetzen JL, Berenbaum MR, Berlin OB, Bjorkman PJ, Blackburn E, Blamont JE, Botchan MR, Boyer JS, Boyle EA, Branton D, Briggs SP, Briggs WR, Brill WJ, Britten RJ, Broecker WS, Brown JH, Brown PO, Brunger AT, Cairns J, Canfield DE, Carpenter SR, Carrington JC, Cashmore AR, Castilla JC, Cazenave A, Chapin FS, Ciechanover AJ, Clapham DE, Clark WC, Clayton RN, Coe MD, Conwell EM, Cowling EB, Cowling RM, Cox CS, Croteau RB, Crothers DM, Crutzen PJ, Daily GC, Dalrymple GB, Dangl JL, Darst SA, Davies DR, Davis MB, De Camilli PV, Dean C, DeFries RS, Deisenhofer J, Delmer DP, DeLong EF, DeRosier DJ, Diener TO, Dirzo R, Dixon JE, Donoghue MJ, Doolittle RF, Dunne T, Ehrlich PR, Eisenstadt SN, Eisner T, Emanuel KA, Englander SW, Ernst WG, Falkowski PG, Feher G, Ferejohn JA, Fersht A, Fischer EH, Fischer R, Flannery KV, Frank J, Frey PA, Fridovich I, Frieden C, Futuyma DJ, Gardner WR, Garrett CJR, Gilbert W, Goldberg RB, Goodenough WH, Goodman CS, Goodman M, Greengard P, Hake S, Hammel G, Hanson S, Harrison SC, Hart SR, Hartl DL, Haselkorn R, Hawkes K, Hayes JM, Hille B, Hökfelt T, House JS, Hout M, Hunten DM, Izquierdo IA, Jagendorf AT, Janzen DH, Jeanloz R, Jencks CS, Jury WA, Kaback HR, Kailath T, Kay P, Kay SA, Kennedy D, Kerr A, Kessler RC, Khush GS, Kieffer SW, Kirch PV, Kirk K, Kivelson MG, Klinman JP, Klug A, Knopoff L, Kornberg H, Kutzbach JE, Lagarias JC, Lambeck K, Landy A, Langmuir CH, Larkins BA, Le Pichon XT, Lenski RE, Leopold EB, Levin SA, Levitt M, Likens GE, Lippincott-Schwartz J, Lorand L, Lovejoy CO, Lynch M, Mabogunje AL, Malone TF, Manabe S, Marcus J, Massey DS, McWilliams JC, Medina E, Melosh HJ, Meltzer DJ, Michener CD, Miles EL, Mooney HA, Moore PB, Morel FMM, Mosley-Thompson ES, Moss B, Munk WH, Myers N, Nair GB, Nathans J, Nester EW, Nicoll RA, Novick RP, O'Connell JF, Olsen PE, Opdyke ND, Oster GF, Ostrom E, Pace NR, Paine RT, Palmiter RD, Pedlosky J, Petsko GA, Pettengill GH, Philander SG, Piperno DR, Pollard TD, Price PB, Reichard PA, Reskin BF, Ricklefs RE, Rivest RL, Roberts JD, Romney AK, Rossmann MG, Russell DW, Rutter WJ, Sabloff JA, Sagdeev RZ, Sahlins MD, Salmond A, Sanes JR, Schekman R, Schellnhuber J, Schindler DW, Schmitt J, Schneider SH, Schramm VL, Sederoff RR, Shatz CJ, Sherman F, Sidman RL, Sieh K, Simons EL, Singer BH, Singer MF, Skyrms B, Sleep NH, Smith BD, Snyder SH, Sokal RR, Spencer CS, Steitz TA, Strier KB, Südhof TC, Taylor SS, Terborgh J, Thomas DH, Thompson LG, Tjian RT, Turner MG, Uyeda S, Valentine JW, Valentine JS, Van Etten JL, van Holde KE, Vaughan M, Verba S, von Hippel PH, Wake DB, Walker A, Walker JE, Watson EB, Watson PJ, Weigel D, Wessler SR, West-Eberhard MJ, White TD, Wilson WJ, Wolfenden RV, Wood JA, Woodwell GM, Wright HE, Wu C, Wunsch C, Zoback ML. Climate change and the integrity of science. Science 2010; 328:689-90. [PMID: 20448167 DOI: 10.1126/science.328.5979.689] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Saint-Paul M, Dumas J, Marcus J. Ultrasonic properties near 50 K of the quasi-one-dimensional conductors A(0.30)MoO(3) (A = K, Rb) and Rb(0.30)(Mo(1-x)V(x))O(3). J Phys Condens Matter 2009; 21:215603. [PMID: 21825552 DOI: 10.1088/0953-8984/21/21/215603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The charge density wave (CDW) nonlinear conductivity of the blue bronzes A(0.30)MoO(3) (A = K, Rb) shows two different regimes depending on the temperature: a strongly damped CDW motion above ∼50 K and a CDW motion with almost no damping below ∼50 K. In a search for an elastic signature of this CDW behaviour, we performed ultrasonic measurements on A(0.30)MoO(3) single crystals in the temperature range 4-300 K. In Rb(0.30)MoO(3), at T∼50 K, upon cooling, a large increase of the sound velocity for the longitudinal mode measured along the [Formula: see text], [102] and b directions is observed. The ultrasonic attenuation coefficient shows an increase down to 50 K followed by a plateau. Similar results are found in K(0.30)MoO(3). In V-doped samples, Rb(0.30)(Mo(1-x)V(x))O(3) (x = 0.4%) the anomaly broadens and is shifted towards higher temperatures. The results are discussed in relation to the changes in the CDW rigidity, disorder and dielectric response. A scenario based on a glass transition for the CDW superstructure is proposed.
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Affiliation(s)
- M Saint-Paul
- Institut Néel, CNRS/UJF, BP 166, F-38042 Grenoble Cedex 9, France
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Ravy S, Le Bolloc'h D, Jacques V, Kirova N, Dumas J, Marcus J, Livet F. Observation of micrometric correlations in sliding incommensurate charge-density waves. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308084833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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van den Boogaart V, de Langen A, Groen HJ, Marcus J, Kappert P, Backes W, Brans B, Hoekstra O, Dingemans AC, Smit EF. A phase II study of erlotinib (E) and bevacizumab (B) in chemo naive patients (pts) with locally advanced or metastatic non small cell lung cancer (NSCLC): Predictive value of molecular imaging. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.8055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Le Bolloc'h D, Jacques VLR, Kirova N, Dumas J, Ravy S, Marcus J, Livet F. Observation of correlations up to the micrometer scale in sliding charge-density waves. Phys Rev Lett 2008; 100:096403. [PMID: 18352733 DOI: 10.1103/physrevlett.100.096403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Indexed: 05/26/2023]
Abstract
A high resolution coherent x-ray diffraction experiment has been performed on the charge-density wave (CDW) system K0.3MoO3. The 2kF satellite reflection associated with the CDW has been measured with respect to external dc currents. In the sliding regime, the 2kF satellite reflection displays secondary satellites along the chain axis which corresponds to correlations up to the micrometer scale. This super long-range order is 1500 times larger than the CDW period itself. This new type of electronic correlation seems inherent to the collective dynamics of electrons in charge-density wave systems. Several scenarios are discussed.
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Affiliation(s)
- D Le Bolloc'h
- Laboratoire de Physique des Solides (CNRS-UMR 8502), Bâtiment 510, Université Paris-sud, 91405 Orsay cedex, France
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Pribulova Z, Klein T, Marcus J, Marcenat C, Levy F, Park MS, Lee HG, Kang BW, Lee SI, Tajima S, Lee S. Anisotropy of the Sommerfeld coefficient in magnesium diboride single crystals. Phys Rev Lett 2007; 98:137001. [PMID: 17501231 DOI: 10.1103/physrevlett.98.137001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Indexed: 05/15/2023]
Abstract
The anisotropic field dependence of the Sommerfeld coefficient gamma has been measured down to B-->0 by combining specific heat and Hall probe magnetization measurements in MgB2 single crystals. We find that gamma(B,theta) is the sum of two contributions arising from the sigma and pi band, respectively. We show that gammasigma(B,theta)=B/Bc2(theta) where Bc2(theta)=Bc2ab/sqrt[sin2theta+Gamma2cos2theta] with Gamma approximately 5.4 (theta being the angle between the applied field and the c axis) and gammapi(B,theta)=gammapi(B)=B/Bpi(B). The "critical field" of the pi band Bpi is fully isotropic but field dependent increasing from approximately 0.25 T for B< or =0.1 T up to 3 T approximately Bc2c for B-->3 T. Because of the coupling of the two bands, superconductivity survives in the pi band up to 3 T but is totally destroyed above for any orientation of the field.
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Affiliation(s)
- Z Pribulova
- Institut Néel-CNRS, F-38042 Grenoble Cedex 9, France
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Escribe-filippini C, Konaté K, Marcus J, Schlenker C, Almairac R, Ayroles R, Roucau C. Evidence for a charge-density-wave instability in the purple bronze K0·9Mo6O17. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/13642818408238857] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- C. Escribe-filippini
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides , CNRS, BP 166, 38042 , Grenoble , Cédex , France
| | - K. Konaté
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides , CNRS, BP 166, 38042 , Grenoble , Cédex , France
| | - J. Marcus
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides , CNRS, BP 166, 38042 , Grenoble , Cédex , France
| | - C. Schlenker
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides , CNRS, BP 166, 38042 , Grenoble , Cédex , France
| | - R. Almairac
- b Groupe de Dynamiques des Phases Condensées, USTL , Place Eugène Bataillon, 34060 , Montpellier , Cédex , France
| | - R. Ayroles
- c Laboratoire d'Optique Electronique , CNRS, BP 434731055, Toulouse , Cédex , France
| | - C. Roucau
- c Laboratoire d'Optique Electronique , CNRS, BP 434731055, Toulouse , Cédex , France
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Schlenker C, Dumas J, Escribe-filippini C, Guyot H, Marcus J, Fourcaudot G. Charge-density-wave instabilities in the low-dimensional molybdenum bronzes and oxides. ACTA ACUST UNITED AC 2006. [DOI: 10.1080/13642818508240627] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- C. Schlenker
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
| | - J. Dumas
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
| | - C. Escribe-filippini
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
| | - H. Guyot
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
| | - J. Marcus
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
| | - G. Fourcaudot
- a Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS , BP 166, 38042 , Grenoble , France
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Abstract
Galactocerebroside (GalC) and sulfatide are abundant myelin lipids. In mice incapable of synthesizing these lipids, myelin is thin and regionally unstable and exhibits several subtle structural abnormalities. Although galactolipid-null mice have been beneficial in the analysis of galactolipid function, it has not been possible to differentiate between the functions of GalC and sulfatide with these mice alone. In the present work, we have analyzed a murine model that forms normal levels of GalC but is incapable of synthesizing sulfatide. By comparing a plethora of morphological features between the galactolipid-null and the sulfatide-null mice, we have begun to differentiate between the specific functions of these closely related lipids. The most striking difference between these two mutants is the reduction of myelin developmental abnormalities (e.g., redundant and uncompacted myelin sheaths) in young adult sulfatide-null mice as compared with the galactolipid-null animals. Although sulfatide appears to play a limited role in myelin development, this lipid is essential for myelin maintenance, as the prevalence of redundant, uncompacted, and degenerating myelin sheaths as well as deteriorating nodal/paranodal structure is increased significantly in aged sulfatide-null mice as compared with littermate wildtype mice. Finally, we show that the role played by sulfatide in CNS maintenance is not limited to the myelin sheath, as axonal caliber and circularity are normal in young adult mutant mice but are significantly altered in aged sulfatide-null animals.
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Affiliation(s)
- J Marcus
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, 23298-0709, USA
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Guyot H, Dumas J, Marcus J, Schlenker C, Vignolles D. High magnetic field magnetoresistance anomalies in the charge density wave state of the quasi-two dimensional bronze KMo6O17. ACTA ACUST UNITED AC 2005. [DOI: 10.1051/jp4:2005131066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Le Bolloc'h D, Ravy S, Dumas J, Marcus J, Livet F, Detlefs C, Yakhou F, Paolasini L. Charge density wave dislocation as revealed by coherent x-ray diffraction. Phys Rev Lett 2005; 95:116401. [PMID: 16197025 DOI: 10.1103/physrevlett.95.116401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Indexed: 05/04/2023]
Abstract
Coherent x-ray diffraction experiments have been performed on high quality crystals of the charge density wave (CDW) system K0.3MoO3. The satellite reflections associated with the CDW have been measured as a function of the 20-microm-diameter beam position. For some positions, regular fringes have been observed. We show that this observation is consistent with the presence of a single CDW dislocation. Beyond charge density wave systems, this experiment shows that coherent x-ray diffraction is a suitable tool to probe topological defects embedded in the bulk.
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Affiliation(s)
- D Le Bolloc'h
- Laboratoire de Physique des Solides, CNRS-UMR 8502, Bâtiment 510, Université Paris-sud, 91405 Orsay cedex, France
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Christensen SA, Haig AJ, Yamakawa KS, Tong HC, Marcus J, Chiodo T. Abstract 6. Arch Phys Med Rehabil 2005. [DOI: 10.1016/j.apmr.2005.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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31
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Kačmarčik J, Marcenat C, Cytermann C, Ferreira da Silva A, Ortega L, Gustafsson F, Marcus J, Klein T, Gheeraert E, Bustarret E. Superconductivity in boron-doped homoepitaxial (001)-oriented diamond layers. ACTA ACUST UNITED AC 2005. [DOI: 10.1002/pssa.200561934] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bustarret E, Kacmarcik J, Marcenat C, Gheeraert E, Cytermann C, Marcus J, Klein T. Dependence of the superconducting transition temperature on the doping level in single-crystalline diamond films. Phys Rev Lett 2004; 93:237005. [PMID: 15601192 DOI: 10.1103/physrevlett.93.237005] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Indexed: 05/24/2023]
Abstract
Homoepitaxial diamond layers doped with boron in the 10(20)-10(21) cm(-3) range are shown to be type II superconductors with sharp transitions (approximately 0.2 K) at temperatures increasing from 0 to 2.1 K with boron contents. The critical concentration for the onset of superconductivity in those 001-oriented single-crystalline films is about 5-7 10(20) cm(-3). The H-T phase diagram has been obtained from transport and ac-susceptibility measurements down to 300 mK.
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Affiliation(s)
- E Bustarret
- Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS, B.P.166, 38042 Grenoble Cedex 9, France
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Lyard L, Szabó P, Klein T, Marcus J, Marcenat C, Kim KH, Kang BW, Lee HS, Lee SI. Anisotropies of the lower and upper critical fields in MgB2 single crystals. Phys Rev Lett 2004; 92:057001. [PMID: 14995332 DOI: 10.1103/physrevlett.92.057001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2003] [Indexed: 05/24/2023]
Abstract
The temperature dependence of the upper (H(c2)) and lower (H(c1)) critical fields has been deduced from Hall probe magnetization measurements of high quality MgB2 single crystals along the two main crystallographic directions. We show that Gamma(H(c2))=H(c2 axially ab)/H(c2 axially c) and Gamma(H(c1))=H(c1 axially c)/H(c1 axially ab) differ significantly at low temperature (being approximately 5 and approximately 1, respectively) and have opposite temperature dependencies. We suggest that MgB2 can be described by a single field dependent anisotropy parameter gamma(H) (=lambda(c)/lambda(ab)=xi(ab)/xi(c)) that increases from Gamma(H(c1)) at low field to Gamma(H(c2)) at high field.
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Affiliation(s)
- L Lyard
- Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS, BP 166, 38042 Grenoble CEDEX 9, France
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Klein T, Marcenat C, Blanchard S, Marcus J, Bourbonnais C, Brusetti R, Van Der Beek CJ, Konczykowski M. Direct transition from Bose glass to normal state in the (K,Ba)BiO3 superconductor. Phys Rev Lett 2004; 92:037005. [PMID: 14753899 DOI: 10.1103/physrevlett.92.037005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2003] [Indexed: 05/24/2023]
Abstract
The introduction of columnar defects in (K,Ba )Bi O3 single crystals shifts both the irreversibility and thermodynamic transition lines, respectively, deduced from ac susceptibility (and/or transport) and specific heat measurements, upwards. This shift can be attributed to the defect-induced decrease of the difference (Delta F) between the free energies in the superconducting and the normal states, assuming that the position of the superconducting transition is given by the condition absolute value Delta F approximately k(B )T/xi(3 ). This criterion also perfectly reproduces the influence of the angle between the tracks and the external field. This result suggests that no vortex liquid phase exists in this system.
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Affiliation(s)
- T Klein
- Laboratoire d'Etudes des Propriétés Electroniques des Solides, CNRS, BP 166, 38042 Grenoble CEDEX 9, France
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35
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Connétable D, Timoshevskii V, Masenelli B, Beille J, Marcus J, Barbara B, Saitta AM, Rignanese GM, Mélinon P, Yamanaka S, Blase X. Superconductivity in doped sp3 semiconductors: the case of the clathrates. Phys Rev Lett 2003; 91:247001. [PMID: 14683147 DOI: 10.1103/physrevlett.91.247001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Indexed: 05/24/2023]
Abstract
We present a joint experimental and theoretical study of the superconductivity in doped silicon clathrates. The critical temperature in Ba(8)@Si-46 is shown to strongly decrease with applied pressure. These results are corroborated by ab initio calculations using MacMillan's formulation of the BCS theory with the electron-phonon coupling constant lambda calculated from perturbative density functional theory. Further, the study of I(8)@Si-46 and of gedanken pure silicon diamond and clathrate phases doped within a rigid-band approach show that the superconductivity is an intrinsic property of the sp(3) silicon network. As a consequence, carbon clathrates are predicted to yield large critical temperatures with an effective electron-phonon interaction much larger than in C60.
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Affiliation(s)
- D Connétable
- LPMCN, Université Claude Bernard Lyon I and CNRS, UMR 5586, Bâtiment Brillouin, 43 Bd du 11 Novembre 1918, 69622 Villeurbanne Cedex, France
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36
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Brusetti R, Bordet P, Marcus J. Investigation of the Rb–W–O system in connexion with the superconducting properties of the hexagonal tungsten bronzes. J SOLID STATE CHEM 2003. [DOI: 10.1016/s0022-4596(03)00006-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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37
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Marcenat C, Blanchard S, Marcus J, Paulius LM, van der Beek CJ, Konczykowski M, Klein T. Anisotropic enhancement of superconductivity in heavy-ion irradiated (K, Ba)BiO3. Phys Rev Lett 2003; 90:037004. [PMID: 12570520 DOI: 10.1103/physrevlett.90.037004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2002] [Indexed: 05/24/2023]
Abstract
We have measured the specific heat, resistivity, and ac susceptibility of (K,Ba)BiO3 single crystals before and after introduction of either point or columnar defects by electron (EI) or heavy-ion irradiation (HII). While the magnetic field dependence of these properties remains mainly unaffected by EI, the irreversibility line and the location of the specific heat anomaly are both shifted up in temperature after HII. The shift is apparent only if the magnetic field is applied parallel to the ion tracks. For perpendicularly applied fields, both lines lie at the same field as in the pristine sample. These experiments call the nature of the vortex liquid state into question.
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Affiliation(s)
- C Marcenat
- Commissariat à l'Energie Atomique-Grenoble, Département de Recherche Fondamentale sur la Matière Condensée, SPSMS, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
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Blanchard S, Klein T, Marcus J, Joumard I, Sulpice A, Szabo P, Samuely P, Jansen AGM, Marcenat C. Anomalous magnetic field dependence of the thermodynamic transition line in the isotropic superconductor (K,Ba)BiO3. Phys Rev Lett 2002; 88:177201. [PMID: 12005780 DOI: 10.1103/physrevlett.88.177201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2001] [Indexed: 05/23/2023]
Abstract
Thermodynamic (specific heat, reversible magnetization, tunneling spectroscopy) and transport measurements have been performed on high quality (K,Ba)BiO3 single crystals. The temperature dependence of the magnetic field H(C(p)) corresponding to the onset of the specific heat anomaly presents a clear positive curvature. H(C(p)) is significantly smaller than the field H(Delta) for which the superconducting gap vanishes but is closely related to the irreversibility line deduced from transport data. Moreover, the temperature dependence of the reversible magnetization presents a strong deviation from the Ginzburg-Landau theory emphasizing the peculiar nature of the superconducting transition in this material.
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Affiliation(s)
- S Blanchard
- Laboratoire d'Etudes des Propriétés Electroniques des Solides, Centre National de la Recherche Scientifique, BP 166, F-38042 Grenoble Cedex 9, France
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Giubileo F, Roditchev D, Sacks W, Lamy R, Thanh DX, Klein J, Miraglia S, Fruchart D, Marcus J, Monod P. Two-gap state density in MgB(2): a true bulk property or a proximity effect? Phys Rev Lett 2001; 87:177008. [PMID: 11690301 DOI: 10.1103/physrevlett.87.177008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2001] [Indexed: 05/23/2023]
Abstract
We report on the temperature dependence of the quasiparticle density of states in the simple binary compound MgB(2) directly measured using scanning tunneling microscope (STM). To achieve high quality tunneling conditions, a small crystal of MgB(2) is used as a tip in the STM experiment. The "sample" is chosen to be a 2H- NbSe(2) single crystal presenting an atomically flat surface. At low temperature the tunneling conductance spectra show a gap at the Fermi energy followed by two well-pronounced conductance peaks on each side. They appear at voltages V(S) approximately +/-3.8 mV and V(L) approximately +/-7.8 mV. With rising temperature both peaks disappear at the T(C) of the bulk MgB(2), a behavior consistent with the model of two-gap superconductivity. The possibility of a particular proximity effect is also discussed.
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Affiliation(s)
- F Giubileo
- Physics Department and INFM Unit, University of Salerno, via S. Allende, 84081 Baronissi (SA), Italy
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Joumard I, Klein T, Marcus J. Evidence for diverging barriers in the disordered vortex solid in the (K,Ba)BiO(3) superconducting oxide. Phys Rev Lett 2001; 87:167002. [PMID: 11690226 DOI: 10.1103/physrevlett.87.167002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2001] [Indexed: 05/23/2023]
Abstract
Vortex dynamics has been investigated in the cubic (K,Ba)BiO (3) superconductor using ac susceptibility measurements on a large frequency range (0.03 Hz<omega<60 kHz). Power law diverging barriers have been obtained on both sides of the order-disorder transition line. The mu exponent remains close to 5/2 (elastic creep value) in some part of the disordered phase and finally decreases at high temperature and/or high field, in good agreement with the recent plastic collective creep theory [J. Kierfeld, H. Nordborg, and V. M. Vinokur, Phys. Rev. Lett., 85, 4948 (2000)].
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Affiliation(s)
- I Joumard
- Laboratoire d'Etudes des Propriétés Electroniques des Solides, Centre National de la Recherche Scientifique, BP 166, 38042 Grenoble Cedex 9, France
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Klein T, Joumard I, Blanchard S, Marcus J, Cubitt R, Giamarchi T, Le Doussal P. A Bragg glass phase in the vortex lattice of a type II superconductor. Nature 2001; 413:404-6. [PMID: 11574883 DOI: 10.1038/35096534] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although crystals are usually quite stable, they are sensitive to a disordered environment: even an infinitesimal amount of impurities can lead to the destruction of crystalline order. The resulting state of matter has been a long-standing puzzle. Until recently it was believed to be an amorphous state in which the crystal would break into 'crystallites'. But a different theory predicts the existence of a novel phase of matter: the so-called Bragg glass, which is a glass and yet nearly as ordered as a perfect crystal. The 'lattice' of vortices that contain magnetic flux in type II superconductors provide a good system to investigate these ideas. Here we show that neutron-diffraction data of the vortex lattice provides unambiguous evidence for a weak, power-law decay of the crystalline order characteristic of a Bragg glass. The theory also predicts accurately the electrical transport properties of superconductors; it naturally explains the observed phase transitions and the dramatic jumps in the critical current associated with the melting of the Bragg glass. Moreover, the model explains experiments as diverse as X-ray scattering in disordered liquid crystals and the conductivity of electronic crystals.
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Affiliation(s)
- T Klein
- Laboratoire d'Etudes des Propriétés Electroniques des Solides-CNRS, BP166, 38042 Grenoble Cedex 9, France.
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Szabó P, Samuely P, Kacmarcík J, Klein T, Marcus J, Fruchart D, Miraglia S, Marcenat C, Jansen AG. Evidence for two superconducting energy gaps in MgB(2) by point-contact spectroscopy. Phys Rev Lett 2001; 87:137005. [PMID: 11580620 DOI: 10.1103/physrevlett.87.137005] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2001] [Indexed: 05/23/2023]
Abstract
Experimental support is found for the multiband model of the superconductivity in the recently discovered system MgB(2) with the transition temperature T(c) = 39 K. By means of Andreev reflection, evidence is obtained for two distinct superconducting energy gaps. The sizes of the two gaps ( Delta(S) = 2.8 meV and Delta(L) = 7 meV) are, respectively, smaller and larger than the expected weak coupling value. Because of the temperature smearing of the spectra the two gaps are hardly distinguishable at elevated temperatures, but when a magnetic field is applied the presence of two gaps can be demonstrated close to the bulk T(c) in the raw data.
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Affiliation(s)
- P Szabó
- Institute of Experimental Physics, Slovak Academy of Sciences, SK-04353 Kosice, Slovakia
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Abstract
OBJECTIVE To better understand whether poor social adjustment, a core characteristic of schizophrenic illness, may also be an indicator of vulnerability in young people who are at genetic risk for schizophrenia, but who do not have schizophrenia. METHOD Between 1992 and 1996, 27 Israeli adolescents with a schizophrenic parent, 29 adolescents with no mentally ill parent, and 30 adolescents with a parent having a nonschizophrenic mental disorder were assessed on multiple domains of social adjustment measured using the Social Adjustment Inventory for Children and Adolescents and the Youth Self-Report. RESULTS Young people with a schizophrenic parent showed poor peer engagement, particularly heterosexual engagement, and social problems characterized by immaturity and unpopularity with peers. These social adjustment difficulties in youths at risk for schizophrenia could not be attributed solely to the presence of early-onset mental disorders, although problems were greater in those with disorders in the schizophrenia spectrum. Young people whose parents had other disorders showed different patterns of social maladjustment characterized by difficult, conflictual relationships with peers and family. CONCLUSION Adolescents at risk for schizophrenia have social deficits that extend beyond early-onset psychopathology and that may reflect vulnerability to schizophrenic disorder.
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Affiliation(s)
- S L Hans
- Department of Psychiatry, The University of Chicago, IL 60637, USA.
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Gweon G, Denlinger JD, Allen JW, Olson CG, Hochst H, Marcus J, Schlenker C. Non-fermi liquid angle resolved photoemission line shapes of li0. 9Mo6O17. Phys Rev Lett 2000; 85:3985. [PMID: 11041982 DOI: 10.1103/physrevlett.85.3985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/1999] [Indexed: 05/23/2023]
Affiliation(s)
- G Gweon
- Randall Laboratory, University of Michigan Ann Arbor, Michigan 48109, USA
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45
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Abstract
The galactolipids galactocerebroside and sulfatide, which require the enzyme UDP-galactose:ceramide galactosyltransferase (CGT) for their synthesis, are among the most prevalent molecules in the myelin sheath. Numerous studies, mainly using antibody perturbation methods in vitro, have suggested that these molecules are crucial mediators of oligodendrocyte differentiation and myelin formation. Although we have previously demonstrated that myelin formation occurs in CGT null mutant mice, which are incapable of synthesizing the myelin galactolipids, here we show that there are developmental alterations in the CNS of these animals. There is a significant decrease in the number of myelinated axon segments in the mutant spinal cord despite normal levels of myelin gene-specific mRNAs and proteins. Also, there is an increased cellularity in the mature mutant spinal cord and the distinctive morphology of the additional cells suggests that they are actively myelinating oligodendrocytes. Using in situ hybridization techniques, we show that there is a 50% increase in the number of oligodendrocytes in the mutant spinal cord. The data suggest that galactolipids play an important developmental role in regulating the maturation program and final number of oligodendrocytes.
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Affiliation(s)
- J Marcus
- Neuroscience Center, University of North Carolina, Chapel Hill, North Carolina 27599-7250, USA
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46
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Hans SL, Marcus J, Nuechterlein KH, Asarnow RF, Styr B, Auerbach JG. Neurobehavioral deficits at adolescence in children at risk for schizophrenia: The Jerusalem Infant Development Study. Arch Gen Psychiatry 1999; 56:741-8. [PMID: 10435609 DOI: 10.1001/archpsyc.56.8.741] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND The Jerusalem Infant Development Study is a prospective investigation comparing offspring of schizophrenic parents with offspring of parents who have no mental disorder or have nonschizophrenic mental disorders. During infancy and school age, a subgroup of offspring of schizophrenic parents showed global neurobehavioral deficits that were hypothesized to be indicators of vulnerability to schizophrenia. The purposes of the present investigation were to determine if neurobehavioral deficits were present in the offspring of schizophrenics at adolescence, to examine their stability over time, and to explore their relation to concurrent mental adjustment. METHODS Sixty-five Israeli adolescents were assessed on a battery of neurologic and neuropsychological assessments. They were also administered psychiatric interviews from which best-estimate DSM-III-R diagnoses and scores of global adjustment were derived. RESULTS Adolescents with poor neurobehavioral functioning were identified from composites of motor and cognitive-attentional variables. A disproportionate number of offspring of schizophrenic parents (42%; 10/24), and especially male offspring of schizophrenic parents (73%; 8/11), showed poor neurobehavioral functioning relative to offspring of nonschizophrenic parents (22%; 9/41). Adolescent offspring of schizophrenics with poor neurobehavioral functioning had been poorly functioning at earlier ages and had poor psychiatric adjustment at adolescence. All 4 offspring of schizophrenics receiving schizophrenia spectrum diagnoses by adolescence showed a pattern of poor neurobehavioral functioning across developmental periods. CONCLUSIONS Results are consistent with the hypothesis that individuals at genetic risk for schizophrenia may display lifelong neurobehavioral signs that are indicators of vulnerability to schizophrenia and that are associated with psychiatric adjustment generally and schizophrenic spectrum disorder specifically.
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Affiliation(s)
- S L Hans
- Department of Psychiatry, The University of Chicago, Ill 60637, USA
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Xia YP, Zhao Y, Marcus J, Jimenez PA, Ruben SM, Moore PA, Khan F, Mustoe TA. Effects of keratinocyte growth factor-2 (KGF-2) on wound healing in an ischaemia-impaired rabbit ear model and on scar formation. J Pathol 1999; 188:431-8. [PMID: 10440755 DOI: 10.1002/(sici)1096-9896(199908)188:4<431::aid-path362>3.0.co;2-b] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Keratinocyte growth factor-2 (KGF-2), also described as fibroblast growth factor-10 (FGF-10), is a member of the fibroblast growth factor family. KGF-2 shares 57 per cent sequence homology to previously reported KGF-1 (FGF-7). In skin, both growth factors are expressed in the dermal compartment. KGF-1 and KGF-2 bind to the same receptor with high affinity, the KGFR isoform of FGFR2, which is exclusively expressed by epithelial cells. This study examines the in vivo function of topically applied KGF-2 on wound healing using an ischaemia-impaired rabbit dermal ulcer model, in young and aged animals. Histological analysis of the wounds showed that KGF-2 significantly promoted re-epithelialization in both young and old animals. Similar results have been observed with KGF-1 in this model. In addition, KGF-2 enhanced granulation tissue formation in both young and old rabbits, a biological effect not found with KGF-1, suggesting a possible indirect mechanism which enhances neo-granulation tissue formation. Immunohistological staining of day 7 wounds with proliferating cell nuclear antigen (PCNA) antibody demonstrated a significant increase of dermal cell proliferation in KGF-2-treated wounds compared with placebo wounds. These results suggest a mesenchymal-epithelial interaction that is mediated by a paracrine feedback loop of KGF-2. Because of the wound healing impairment observed with ageing, the wound healing response to KGF-2 was also studied in ischaemic wounds of aged animals. Administration of KGF-2 led to significant stimulation of epithelial growth and granulation tissue formation. The effects seen in the old animals were delayed compared with the young animals. Lastly, the effect of KGF-2 was examined in a rabbit model of scar formation. Quantification of scar elevation index showed no significant differences in scar formation when KGF-2 was compared with buffer placebo. Compared with other growth factors, including KGF-1 and TGF-beta which have previously been examined in these models, KGF-2 is the most effective and causes no obvious scarring.
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Affiliation(s)
- Y P Xia
- Department of Surgery, Northwestern University, Chicago, IL 60611, USA
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Abstract
Fish and mammal bones from the coastal site of Cerro Azul, Peru shed light on economic specialization just before the Inca conquest of A. D. 1470. The site devoted itself to procuring anchovies and sardines in quantity for shipment to agricultural communities. These small fish were dried, stored, and eventually transported inland via caravans of pack llamas. Cerro Azul itself did not raise llamas but obtained charqui (or dried meat) as well as occasional whole adult animals from the caravans. Guinea pigs were locally raised. Some 20 species of larger fish were caught by using nets; the more prestigious varieties of these show up mainly in residential compounds occupied by elite families.
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Affiliation(s)
- J Marcus
- Museum of Anthropology, 1109 Geddes Avenue, University of Michigan, Ann Arbor, MI 48109-1079, USA.
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Abstract
This is an 11 month old girl who has been referred to our institute for a seizure disorder. Her physical examination showed angiomas on the left side of her face, and more extensive and prominent ones on her palms and soles. Her right face and arm were smaller than the left, associated with hypotonia and moderate weakness in the right forearm. Computerized tomography of head showed intracranial calcification in the left fronto-parietal region, and brain MRI, with gadolinium, revealed an extensive leptomeningeal angioma over the entire left hemisphere. This case was diagnosed as Sturge-Weber syndrome with unusual cutaneous manifestations.
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Affiliation(s)
- C Inan
- State University of New York at Brooklyn, Division of Pediatric Neurology, Brooklyn 11203, USA.
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Daniels TJ, Boccia TM, Varde S, Marcus J, Le J, Bucher DJ, Falco RC, Schwartz I. Geographic risk for lyme disease and human granulocytic ehrlichiosis in southern New York state. Appl Environ Microbiol 1998; 64:4663-9. [PMID: 9835546 PMCID: PMC90906 DOI: 10.1128/aem.64.12.4663-4669.1998] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Ixodes scapularis, the tick vector of Lyme disease and human granulocytic ehrlichiosis (HGE), is prevalent in much of southern New York state. The distribution of this species has increased, as have reported cases of both Lyme disease and HGE. The unreliability of case reports, however, demonstrates the need for tick and pathogen surveillance in order to accurately define areas of high risk. In this study, a total of 89,550 m2 at 34 study sites was drag sampled in 1995 and a total of 51,540 m2 at 40 sites was sampled in 1996 to determine tick and pathogen distribution in southern New York state. I. scapularis was collected from 90% of the sites sampled, and regionally, a 2.5-fold increase in nymphal abundance occurred from 1995 to 1996. I. scapularis individuals from all sites were infected with Borrelia burgdorferi in 1995, while an examination of ticks for both B. burgdorferi and the agent of HGE in 1996 confirmed that these organisms were present in all counties; the average coinfection rate was 1.9%. No correlation was found between estimated risk and reported cases of Lyme disease. The geographic disparity of risk observed among sites in this study underscores the need for vector and pathogen surveillance on a regional level. An entomologic risk index can help identify sites for targeted tick control efforts.
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Affiliation(s)
- T J Daniels
- Vector Ecology Laboratory, Louis Calder Center, Fordham University, Armonk, New York 10504, USA.
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