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Link S, Loh G, Gartner M. Broncholithiasis – a rare initial presentation of lithopytsis. Am J Med Sci 2023. [DOI: 10.1016/s0002-9629(23)00485-8] [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: 01/28/2023]
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2
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Qu AC, Nigge P, Link S, Levy G, Michiardi M, Spandar PL, Matthé T, Schneider M, Zhdanovich S, Starke U, Gutiérrez C, Damascelli A. Ubiquitous defect-induced density wave instability in monolayer graphene. Sci Adv 2022; 8:eabm5180. [PMID: 35675409 PMCID: PMC9177069 DOI: 10.1126/sciadv.abm5180] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 04/20/2022] [Indexed: 06/15/2023]
Abstract
Quantum materials are notoriously sensitive to their environments, where small perturbations can tip a system toward one of several competing ground states. Graphene hosts a rich assortment of such competing phases, including a bond density wave instability ("Kekulé distortion") that couples electrons at the K/K' valleys and breaks the lattice symmetry. Here, we report observations of a ubiquitous Kekulé distortion across multiple graphene systems. We show that extremely dilute concentrations of surface atoms (less than three adsorbed atoms every 1000 graphene unit cells) can self-assemble and trigger the onset of a global Kekulé density wave phase. Combining complementary momentum-sensitive angle-resolved photoemission spectroscopy (ARPES) and low-energy electron diffraction (LEED) measurements, we confirm the presence of this density wave phase and observe the opening of an energy gap. Our results reveal an unexpected sensitivity of the graphene lattice to dilute surface disorder and show that adsorbed atoms offer an attractive route toward designing novel phases in two-dimensional materials.
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Affiliation(s)
- A. C. Qu
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - P. Nigge
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - S. Link
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - G. Levy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - M. Michiardi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - P. L. Spandar
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA, USA
| | - T. Matthé
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - M. Schneider
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - S. Zhdanovich
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
| | - U. Starke
- Max Planck Institute for Solid State Research, Stuttgart, Germany
| | - C. Gutiérrez
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA, USA
| | - A. Damascelli
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, Canada
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3
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Nigge P, Qu AC, Lantagne-Hurtubise É, Mårsell E, Link S, Tom G, Zonno M, Michiardi M, Schneider M, Zhdanovich S, Levy G, Starke U, Gutiérrez C, Bonn D, Burke SA, Franz M, Damascelli A. Room temperature strain-induced Landau levels in graphene on a wafer-scale platform. Sci Adv 2019; 5:eaaw5593. [PMID: 31723598 PMCID: PMC6839937 DOI: 10.1126/sciadv.aaw5593] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 09/17/2019] [Indexed: 05/17/2023]
Abstract
Graphene is a powerful playground for studying a plethora of quantum phenomena. One of the remarkable properties of graphene arises when it is strained in particular geometries and the electrons behave as if they were under the influence of a magnetic field. Previously, these strain-induced pseudomagnetic fields have been explored on the nano- and micrometer-scale using scanning probe and transport measurements. Heteroepitaxial strain, in contrast, is a wafer-scale engineering method. Here, we show that pseudomagnetic fields can be generated in graphene through wafer-scale epitaxial growth. Shallow triangular nanoprisms in the SiC substrate generate strain-induced uniform fields of 41 T, enabling the observation of strain-induced Landau levels at room temperature, as detected by angle-resolved photoemission spectroscopy, and confirmed by model calculations and scanning tunneling microscopy measurements. Our work demonstrates the feasibility of exploiting strain-induced quantum phases in two-dimensional Dirac materials on a wafer-scale platform, opening the field to new applications.
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Affiliation(s)
- P. Nigge
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - A. C. Qu
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - É. Lantagne-Hurtubise
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - E. Mårsell
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Division of Molecular and Condensed Matter Physics, Department of Physics and Astronomy, Uppsala University, P.O. Box 516, 751 20 Uppsala, Sweden
| | - S. Link
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - G. Tom
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - M. Zonno
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - M. Michiardi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany
| | - M. Schneider
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - S. Zhdanovich
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - G. Levy
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - U. Starke
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - C. Gutiérrez
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - D. Bonn
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - S. A. Burke
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Corresponding author. (S.A.B.); (M.F.); (A.D.)
| | - M. Franz
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Corresponding author. (S.A.B.); (M.F.); (A.D.)
| | - A. Damascelli
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
- Corresponding author. (S.A.B.); (M.F.); (A.D.)
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4
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Shen G, Link S, Kumar S, Nusbaum DM, Tse DY, Fu Y, Wu SM, Frankfort BJ. Author Correction: Characterization of Retinal Ganglion Cell and Optic Nerve Phenotypes Caused by Sustained Intracranial Pressure Elevation in Mice. Sci Rep 2019; 9:14727. [PMID: 31591458 PMCID: PMC6779737 DOI: 10.1038/s41598-019-46779-4] [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] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Schuyler Link
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Sandeep Kumar
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Derek M Nusbaum
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Dennis Y Tse
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
| | - Yingbin Fu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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5
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Shen G, Link S, Kumar S, Nusbaum DM, Tse DY, Fu Y, Wu SM, Frankfort BJ. Characterization of Retinal Ganglion Cell and Optic Nerve Phenotypes Caused by Sustained Intracranial Pressure Elevation in Mice. Sci Rep 2018; 8:2856. [PMID: 29434244 PMCID: PMC5809383 DOI: 10.1038/s41598-018-21254-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 01/31/2018] [Indexed: 12/16/2022] Open
Abstract
Elevated intracranial pressure (ICP) can result in multiple neurologic sequelae including vision loss. Inducible models of ICP elevation are lacking in model organisms, which limits our understanding of the mechanism by which increased ICP impacts the visual system. We adapted a mouse model for the sustained elevation of ICP and tested the hypothesis that elevated ICP impacts the optic nerve and retinal ganglion cells (RGCs). ICP was elevated and maintained for 2 weeks, and resulted in multiple anatomic changes that are consistent with human disease including papilledema, loss of physiologic cupping, and engorgement of the optic nerve head. Elevated ICP caused a loss of RGC somas in the retina and RGC axons within the optic nerve, as well as a reduction in both RGC electrical function and contrast sensitivity. Elevated ICP also caused increased hypoxia-inducible factor (HIF)-1 alpha expression in the ganglion cell layer. These experiments confirm that sustained ICP elevation can be achieved in mice and causes phenotypes that preferentially impact RGCs and are similar to those seen in human disease. With this model, it is possible to model human diseases of elevated ICP such as Idiopathic Intracranial Hypertension and Spaceflight Associated Neuro-ocular Syndrome.
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Affiliation(s)
- Guofu Shen
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Schuyler Link
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Sandeep Kumar
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Derek M Nusbaum
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Dennis Y Tse
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,School of Optometry, The Hong Kong Polytechnic University, Hong Kong, Hong Kong
| | - Yingbin Fu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Samuel M Wu
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Benjamin J Frankfort
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA. .,Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.
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6
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Sforzini J, Hapala P, Franke M, van Straaten G, Stöhr A, Link S, Soubatch S, Jelínek P, Lee TL, Starke U, Švec M, Bocquet FC, Tautz FS. Structural and Electronic Properties of Nitrogen-Doped Graphene. Phys Rev Lett 2016; 116:126805. [PMID: 27058093 DOI: 10.1103/physrevlett.116.126805] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 06/05/2023]
Abstract
We investigate the structural and electronic properties of nitrogen-doped epitaxial monolayer graphene and quasifreestanding monolayer graphene on 6H-SiC(0001) by the normal incidence x-ray standing wave technique and by angle-resolved photoelectron spectroscopy supported by density functional theory simulations. With the location of various nitrogen species uniquely identified, we observe that for the same doping procedure, the graphene support, consisting of substrate and interface, strongly influences the structural as well as the electronic properties of the resulting doped graphene layer. Compared to epitaxial graphene, quasifreestanding graphene is found to contain fewer nitrogen dopants. However, this lack of dopants is compensated by the proximity of nitrogen atoms at the interface that yield a similar number of charge carriers in graphene.
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Affiliation(s)
- J Sforzini
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - P Hapala
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - M Franke
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - G van Straaten
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - A Stöhr
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - S Link
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - S Soubatch
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - P Jelínek
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - T-L Lee
- Diamond Light Source Ltd, Didcot OX110DE, Oxfordshire, United Kingdom
| | - U Starke
- Max Planck Institute for Solid State Research, Heisenbergstraße, 70569 Stuttgart, Germany
| | - M Švec
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10, 16200 Prague, Czech Republic
| | - F C Bocquet
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
| | - F S Tautz
- Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany
- Jülich Aachen Research Alliance (JARA), Fundamentals of Future Information Technology, 52425 Jülich, Germany
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7
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Gierz I, Calegari F, Aeschlimann S, Chávez Cervantes M, Cacho C, Chapman RT, Springate E, Link S, Starke U, Ast CR, Cavalleri A. Tracking Primary Thermalization Events in Graphene with Photoemission at Extreme Time Scales. Phys Rev Lett 2015; 115:086803. [PMID: 26340199 DOI: 10.1103/physrevlett.115.086803] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Indexed: 05/13/2023]
Abstract
Direct and inverse Auger scattering are amongst the primary processes that mediate the thermalization of hot carriers in semiconductors. These two processes involve the annihilation or generation of an electron-hole pair by exchanging energy with a third carrier, which is either accelerated or decelerated. Inverse Auger scattering is generally suppressed, as the decelerated carriers must have excess energies higher than the band gap itself. In graphene, which is gapless, inverse Auger scattering is, instead, predicted to be dominant at the earliest time delays. Here, <8 fs extreme-ultraviolet pulses are used to detect this imbalance, tracking both the number of excited electrons and their kinetic energy with time-and angle-resolved photoemission spectroscopy. Over a time window of approximately 25 fs after absorption of the pump pulse, we observe an increase in conduction band carrier density and a simultaneous decrease of the average carrier kinetic energy, revealing that relaxation is in fact dominated by inverse Auger scattering. Measurements of carrier scattering at extreme time scales by photoemission will serve as a guide to ultrafast control of electronic properties in solids for petahertz electronics.
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Affiliation(s)
- I Gierz
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - F Calegari
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
- Institute for Photonics and Nanotechnologies, IFN-CNR, 20133 Milano, Italy
| | - S Aeschlimann
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - M Chávez Cervantes
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
| | - C Cacho
- Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom
| | - R T Chapman
- Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom
| | - E Springate
- Central Laser Facility, STFC Rutherford Appleton Laboratory, OX11 0QX Harwell, United Kingdom
| | - S Link
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - U Starke
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - C R Ast
- Max Planck Institute for Solid State Research, 70569 Stuttgart, Germany
| | - A Cavalleri
- Max Planck Institute for the Structure and Dynamics of Matter, Center for Free Electron Laser Science, 22761 Hamburg, Germany
- Department of Physics, Clarendon Laboratory, University of Oxford, OX1 3PU Oxford, United Kingdom
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8
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Spoerri I, Scherer K, Michel S, Link S, Bircher AJ, Heijnen IAFM. Detection of nickel and palladium contact hypersensitivity by a flow cytometric lymphocyte proliferation test. Allergy 2015; 70:323-7. [PMID: 25443647 DOI: 10.1111/all.12553] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2014] [Indexed: 11/30/2022]
Abstract
We established a flow cytometric lymphocyte proliferation test (LPT) for the detection of nickel (Ni) and palladium (Pd) sensitization. Eighty-one consecutive patients with an indication for patch test (PT) were tested by LPT with Ni (NiSO4 ) and Pd (Na2 PdCl4 and PdCl2 ) salts. The imprecision of the LPT was low (coefficient of variation 7.2%). Using PT as a diagnostic reference, the sensitivity and specificity of LPT were 74.4% and 80% for NiSO4 , 74.4% and 78.3% for Na2 PdCl4 , and 57.2% and 85.4% for PdCl2 , respectively. For both Ni and Pd, the likelihood ratio for a positive PT markedly increased with increasing LPT value. With medical history as a reference, the sensitivity and specificity were 40.6% and 82.1% for LPT and 59.4% and 89.7% for PT, respectively. Combination of LPT and PT resulted in a higher specificity of 95%, albeit lower sensitivity of 34.4%. In conclusion, flow cytometric LPT represents a reliable and useful method for the detection of Ni and Pd sensitization. LPT values correlate with PT results and, when used in combination with PT, increase test specificity.
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Affiliation(s)
- I. Spoerri
- Research Group of Dermatology; Department of Biomedicine; University Hospital Basel; University of Basel; Basel Switzerland
| | - K. Scherer
- Allergy Unit; Department of Dermatology; University Hospital Basel; Basel Switzerland
| | - S. Michel
- Allergy Unit; Department of Dermatology; University Hospital Basel; Basel Switzerland
| | - S. Link
- Medical Immunology, Laboratory Medicine; University Hospital Basel; Basel Switzerland
| | - A. J. Bircher
- Allergy Unit; Department of Dermatology; University Hospital Basel; Basel Switzerland
| | - I. A. F. M. Heijnen
- Medical Immunology, Laboratory Medicine; University Hospital Basel; Basel Switzerland
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9
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Fischer FSU, Tremel K, Saur AK, Link S, Kayunkid N, Brinkmann M, Herrero-Carvajal D, Navarrete JTL, Delgado MCR, Ludwigs S. Influence of Processing Solvents on Optical Properties and Morphology of a Semicrystalline Low Bandgap Polymer in the Neutral and Charged States. Macromolecules 2013. [DOI: 10.1021/ma400939z] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- F. S. U. Fischer
- IPOC-Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - K. Tremel
- IPOC-Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - A.-K. Saur
- IPOC-Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - S. Link
- IPOC-Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - N. Kayunkid
- Institut Charles Sadron (UPR22), CNRS 23 rue du Loess, 67034 Strasbourg Cedex 2, France
| | - M. Brinkmann
- Institut Charles Sadron (UPR22), CNRS 23 rue du Loess, 67034 Strasbourg Cedex 2, France
| | - D. Herrero-Carvajal
- Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n,
Málaga 29071, Spain
| | - J. T. López Navarrete
- Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n,
Málaga 29071, Spain
| | - M. C. Ruiz Delgado
- Department of Physical Chemistry, University of Málaga, Campus de Teatinos s/n,
Málaga 29071, Spain
| | - S. Ludwigs
- IPOC-Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
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Burda C, Green TC, Link S, El-Sayed MA. Femtosecond Interfacial Electron Transfer Dynamics of CdSe Semiconductor Nanoparticles. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-536-419] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractThe effect of the adsorption of an electron donor (thiophenol, TP) on the surface of CdSe nanoparticles (NPs) on the emission and electron-hole dynamics is studied. It is found that while the emission is completely quenched, the effect on the transient bleach recovery of the band gap absorption is only slight. This is explained by a mechanism in which the hole in the valence band of the NP is rapidly neutralized by electron transfer from the TP. However, the excited electron in the conduction band is not transferred to the TP cation, i. e. the electron does not shuttle via the organic moiety as it does when naphthoquinone is adsorbed [1]. The excited electron is rather trapped by surface states. Thus the rate of bleach recovery in the CdSe NP system is determined by the rate of electron trapping and not by hole trapping. Comparable conclusions resulted previously [2] for the CdS NP when the CdS-MV2+ system is studied. A comparative discussion of the electron-hole dynamics in these systems (CdSe-NQ, CdS-MV2+ and CdSe-TP) is given.
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11
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Lee K, Link S, Ge L. Photographic Memory of Unfamiliar Faces Under 30 Seconds. J Vis 2010. [DOI: 10.1167/10.7.619] [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: 11/24/2022] Open
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12
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Tcherniak A, Ha JW, Dominguez-Medina S, Slaughter LS, Link S. Probing a century old prediction one plasmonic particle at a time. Nano Lett 2010; 10:1398-1404. [PMID: 20196552 DOI: 10.1021/nl100199h] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In 1908, Gustav Mie solved Maxwell's equations to account for the absorption and scattering of spherical plasmonic particles. Since then much attention has been devoted to the size dependent optical properties of metallic nanoparticles. However, ensemble measurements of colloidal solutions generally only yield the total extinction cross sections of the nanoparticles. Here, we show how Mie's prediction on the size dependence of the surface absorption and scattering can be probed separately for the same gold nanoparticle by using two single particle spectroscopy techniques, (1) dark-field scattering and (2) photothermal imaging, which selectively only measure scattering and absorption, respectively. Combining the optical measurements with correlated scanning electron microscopy furthermore allowed us to measure the size of the spherical gold nanoparticles, which ranged from 43 to 274 nm in diameter. We found that even though the trend predicted by Mie theory is followed well by the experimental data over a large range of nanoparticle diameters, for small size variations changes in scattering and absorption intensities are dominated by factors other than those considered by Mie theory. In particular, spectral shifts of the plasmon resonance due to deviations from a spherical particle shape alone cannot explain the observed variation in absorption and scattering intensities.
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Affiliation(s)
- A Tcherniak
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
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Link S, Osterhues HH, Erné SN. Software-Plattform für die Analyse elektro- und magnetokardiographischer Datenbanken. BIOMED ENG-BIOMED TE 2009. [DOI: 10.1515/bmte.1998.43.s1.96] [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: 11/15/2022]
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14
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Abstract
A combination of single-molecule spectroscopy and analysis with simulations is used to provide detailed information about the structural and dynamic properties of a fluorescent polymer MEH-PPV (poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene]) immersed in a nematic and smectic solvent. In nematic solvents, single-polymer molecules are oriented strongly along the solvent director, much more so than the solvent molecules, confirming Onsager's old prediction. The diffusion anisotropy parallel and perpendicular to the solvent director, however, is less than two, which is similar to that of a spherical colloid in a nematic solvent. In smectic solvents, there is a second orientation of the dissolved polymer perpendicular to the solvent director, which we hypothesize is caused by the polymer occupying the interlayer volume. The research discussed here emphasizes the importance of organization in complex fluids and suggests that the interplay of order on different length scales could be exploited to fabricate novel nanostructured materials.
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Affiliation(s)
- P F Barbara
- Center for Nano- and Molecular Science and Technology, and Department of Chemistry and Biochemistry, University of Texas, Austin, TX 78712, USA.
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15
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Abstract
We examine the effect of polymer chain segmentation on the recently discovered ability of nematic solvents to elongate and align polymer chain solutes. Coordinated single molecule spectroscopy and beads-on-a-chain simulations are used to study the orientational and conformational order of a series of segmented conjugated polymers, dissolved in the nematic liquid crystal 5CB. The order parameters for alignment and elongation are both observed to decrease with increasing segmentation, reflecting an interplay among conformational entropy, solvation anisotropy, and bending energy of the chain.
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Affiliation(s)
- S Link
- Center for Nano- and Molecular Science and Technology, University of Texas at Austin, Austin, Texas 78712, USA
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16
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Link S, El-Sayed MA. Simulation of the Optical Absorption Spectra of Gold Nanorods as a Function of Their Aspect Ratio and the Effect of the Medium Dielectric Constant. J Phys Chem B 2005. [DOI: 10.1021/jp058091f] [Citation(s) in RCA: 200] [Impact Index Per Article: 10.5] [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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17
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Marcinkeviciene J, Rogers MJ, Kopcho L, Jiang W, Wang K, Murphy DJ, Lippy J, Link S, Chung TD, Hobbs F, Haque T, Trainor GL, Slee A, Stern AM, Copeland RA. Selective inhibition of bacterial dihydroorotate dehydrogenases by thiadiazolidinediones. Biochem Pharmacol 2000; 60:339-42. [PMID: 10856428 DOI: 10.1016/s0006-2952(00)00348-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [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: 10/18/2022]
Abstract
Dihydroorotate dehydrogenase is a critical enzyme of de novo pyrimidine biosynthesis in prokaryotic and eukaryotic cells. Differences in the primary structure of the enzymes from Gram-positive and -negative bacteria and from mammals indicate significant structural divergence among these enzymes. We have identified a class of small molecules, the thiadiazolidinediones, that inhibit prototypical enzymes from Gram-positive and -negative bacteria, but are inactive against the human enzyme. The most potent compound in our collection functioned as a time-dependent irreversible inactivator of the bacterial enzymes with k(inact)/K(i) values of 48 and 500 M(-1) sec(-1) for the enzymes from Escherichia coli and Enterococcus faecalis, respectively. The data presented here indicate that it is possible to inhibit prokaryotic dihydroorotate dehydrogenases selectively while sparing the mammalian enzyme. Thus, this enzyme may represent a valuable target for the development of novel antibiotic compounds.
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Affiliation(s)
- J Marcinkeviciene
- Department of Chemical Enzymology, The DuPont Pharmaceuticals Co., Wilmington, DE 19880-0400, USA
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Burda C, Abdel-Kader MH, Link S, El-Sayed MA. Femtosecond Dynamics of a Simple Merocyanine Dye: Does Deprotonation Compete with Isomerization? J Am Chem Soc 2000. [DOI: 10.1021/ja993940w] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- C. Burda
- Contribution from the Laser Dynamics Laboratory, Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, and National Institute for Laser Enhanced Science, Cairo University, Egypt
| | - M. H. Abdel-Kader
- Contribution from the Laser Dynamics Laboratory, Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, and National Institute for Laser Enhanced Science, Cairo University, Egypt
| | - S. Link
- Contribution from the Laser Dynamics Laboratory, Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, and National Institute for Laser Enhanced Science, Cairo University, Egypt
| | - M. A. El-Sayed
- Contribution from the Laser Dynamics Laboratory, Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, and National Institute for Laser Enhanced Science, Cairo University, Egypt
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20
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Link S, Burda C, Nikoobakht B, El-Sayed MA. Laser-Induced Shape Changes of Colloidal Gold Nanorods Using Femtosecond and Nanosecond Laser Pulses. J Phys Chem B 2000. [DOI: 10.1021/jp000679t] [Citation(s) in RCA: 649] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Link
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - C. Burda
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - B. Nikoobakht
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - M. A. El-Sayed
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
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21
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Link S, Häring G, Hedderich J. [Effect of phacoemulsification and posterior chamber lens implantation on intraocular pressure in patients with and without open-angle glaucoma]. Ophthalmologe 2000; 97:402-6. [PMID: 10916382 DOI: 10.1007/s003470070088] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [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: 11/25/2022]
Abstract
BACKGROUND Many of the previous studies which dealt with the influence of cataract surgery on intraocular pressure, were performed retrospectively and based on heterogeneous groups of patients. Therefore, the purpose of our study was to prospectively assess the effect of phacoemulsification and posterior chamber intraocular-lens (IOL)-implantation on intraocular pressure (IOP) under standardized conditions in patients with and without open-angle-glaucoma. PATIENTS AND METHODS Overall 52 patients were recruited for the study. 34 eyes with normal IOP and 16 eyes with open-angle-glaucoma were operated with the same technique. RESULTS Mean IOP in patients with cataract and without glaucoma was preoperatively 15.1 mmHg. 6 months postoperatively these patients showed a mean decrease of IOP of 11.9% (1.8 mmHg +/- 3.8; p = 0.027); after 12 months IOP showed a decrease of 18.5% (2.8 mmHg +/- 3.5; p = 0.0001). In patients with glaucoma mean IOP was preoperatively 17.3 mmHg. IOP was reduced by 23.7% (4.1 mmHg +/- 6.0; p = 0.017) 6 months after cataract surgery and 22.6% (3.9 mmHg +/- 4.5; p = 0.005) 12 months after the operation. In 6 of 16 eyes the antiglaucoma medication could be suspended. CONCLUSION Reduction of IOP is a positive side effect of phacoemulsification and posterior chamber IOL implantation and should be considered when indicating cataract surgery in patients with glaucoma and only slight elevation of IOP.
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Affiliation(s)
- S Link
- Klinik für Ophthalmologie der Christian-Albrechts-Universität zu Kiel
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22
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Berg W, Linder C, Eschholz G, Link S, Schubert J. Possibility of improving the acceptance rateof early detection testing for prostate cancerwith a one-step test for prostate-specific antigen in whole blood. Urol Int 1999; 63:102-6. [PMID: 10592497 DOI: 10.1159/000030426] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [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: 11/19/2022]
Abstract
In order to increase the acceptance rate of early detection testing for prostate cancer, a qualitative prostate-specific antigen (PSA) one-step test has been developed. Determining the PSA level with this test system takes 10 min. The blood samples of 190 men were tested in this qualitative assay, which uses 50 microl of EDTA whole blood and in which the results are ascertained visually. Parallel samples were tested in serum-based, quantitative assays (Abbott Imx, EIA). The findings of the two kinds of assays were compared and evaluated regarding their correspondence (<4.0 and > or = 4.0 ng/ml). For the 74 blood samples in which the quantitative assay showed PSA levels <4.0 ng/ml, the PSA one-step test showed 83.8% correct negative results (corresponds to diagnostic specificity). For the 116 samples in which the classic assay showed PSA levels > or = 4.0 ng/ml, the one-step test showed 90.5% correct positive results (sensitivity). The noted deviations appear especially around the cut-off value of 4.0 ng/ml, i.e. within the PSA concentration range of 3.0 < 4.0 and 4.0 < 5.0 ng/ml. The qualitative PSA one-step test presented here demonstrates good reproducibility. It can be conducted by the patient and is easy to use. The test offers a simple, feasible method for early detection programs for prostate cancer.
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Affiliation(s)
- W Berg
- Department of Urology, University Hospital, Friedrich Schiller University, Jena, Germany.
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23
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Burda C, Link S, Green TC, El-Sayed MA. New Transient Absorption Observed in the Spectrum of Colloidal CdSe Nanoparticles Pumped with High-Power Femtosecond Pulses. J Phys Chem B 1999. [DOI: 10.1021/jp991503y] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C. Burda
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - S. Link
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - T. C. Green
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - M. A. El-Sayed
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
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Link S, Burda C, Wang ZL, El-Sayed MA. Electron dynamics in gold and gold–silver alloy nanoparticles: The influence of a nonequilibrium electron distribution and the size dependence of the electron–phonon relaxation. J Chem Phys 1999. [DOI: 10.1063/1.479310] [Citation(s) in RCA: 292] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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25
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Link S, Wang ZL, El-Sayed MA. Alloy Formation of Gold−Silver Nanoparticles and the Dependence of the Plasmon Absorption on Their Composition. J Phys Chem B 1999. [DOI: 10.1021/jp990387w] [Citation(s) in RCA: 1173] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. Link
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, and School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - Z. L. Wang
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, and School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - M. A. El-Sayed
- Laser Dynamics Laboratory, School of Chemistry and Biochemistry, and School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
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26
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Link S, Mohamed MB, El-Sayed MA. Simulation of the Optical Absorption Spectra of Gold Nanorods as a Function of Their Aspect Ratio and the Effect of the Medium Dielectric Constant. J Phys Chem B 1999. [DOI: 10.1021/jp990183f] [Citation(s) in RCA: 1267] [Impact Index Per Article: 50.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Burda C, Green TC, Link S, El-Sayed MA. Electron Shuttling Across the Interface of CdSe Nanoparticles Monitored by Femtosecond Laser Spectroscopy. J Phys Chem B 1999. [DOI: 10.1021/jp9843050] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. Burda
- Laser Dynamics Laboratory, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - T. C. Green
- Laser Dynamics Laboratory, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - S. Link
- Laser Dynamics Laboratory, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
| | - M. A. El-Sayed
- Laser Dynamics Laboratory, Georgia Institute of Technology, Atlanta, Georgia 30332-0400
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28
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Link S, Burda C, Mohamed MB, Nikoobakht B, El-Sayed MA. Laser Photothermal Melting and Fragmentation of Gold Nanorods: Energy and Laser Pulse-Width Dependence. J Phys Chem A 1999. [DOI: 10.1021/jp983141k] [Citation(s) in RCA: 420] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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29
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Link S, Osterhues HH, Erné SN. [Software platform for analysis of electro- and magnetocardiography databanks]. BIOMED ENG-BIOMED TE 1998; 43 Suppl:96-7. [PMID: 9859275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- S Link
- Arbeitsbereich Erfassung und Verarbeitung von Biosignalen, Universität Ulm
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30
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Abstract
This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations between 1989 and 1993, and compared to a previously investigated reference population. In more than 20% of the women, at least one of the CHC levels exceeded the reference range. CHC levels did not differ significantly between women with primary or secondary and early or late miscarriages; neither did they differ between women with hormonal or immunological disorders as causes of repeated miscarriages or women with idiopathic repeated miscarriages. No significant associations were detected between CHC levels and further conceptions or the outcome of further pregnancies. As significant associations were found between increasing CHC blood concentrations and immunological and hormonal changes, CHCs may have an impact on the pregnancy course in certain cases.
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Affiliation(s)
- I Gerhard
- Department of Gynecological Endocrinology and Reproduction, Women's Hospital, Department of Transplantation Immunology, University of Heidelberg, Heidelberg, Germany
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31
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Little RB, Burda C, Link S, Logunov S, El-Sayed MA. Charge Separation Effects on the Rate of Nonradiative Relaxation Processes in Quantum Dots−Quantum Well Heteronanostructures. J Phys Chem A 1998. [DOI: 10.1021/jp9822687] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. B. Little
- Laser Dynamics Laboratory, Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
| | - C. Burda
- Laser Dynamics Laboratory, Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
| | - S. Link
- Laser Dynamics Laboratory, Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
| | - S. Logunov
- Laser Dynamics Laboratory, Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
| | - M. A. El-Sayed
- Laser Dynamics Laboratory, Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, Georgia 30332-0400
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Abstract
The glycoprotein CD14 acts as a receptor for lipopolysaccharide (LPS), either when anchored in the myeloid cell membrane (mCD14) or as a soluble molecule (sCD14) in serum. sCD14-LPS complexes activate cells devoid of mCD14. However, the role of sCD14 independent of LPS is unknown. Therefore, the effect of sCD14 on monocyte functions was investigated in the monocytic cell lines THP1 and Mono Mac 6 and in fresh human monocytes. Under serum-free conditions, endotoxin-free human recombinant sCD14(1-348), (rsCD14(1-348)) induced tumor necrosis factor alpha (TNF-alpha). The TNF-alpha effect was stronger in THP1 cells than in Mono Mac 6 cells or monocytes. It was dose dependent, with a maximum at 1 microg/ml, and time dependent, with a maximum after 2 h. sCD14 purified from urine had the same cytokine-activating capacity. In contrast, C-terminally truncated rsCD14(1-152) was inactive. The rsCD14 effect was not due to LPS contamination, since it was resistant to polymyxin and lipid IVa but sensitive to heat and trypsin. The rsCD14-induced cytokine induction was blocked by preincubation of rsCD14 with a monoclonal anti-CD14 antibody that did not recognize the LPS-binding site. Release of the TNF-alpha disappeared upon pretreatment of rsCD14 in 50% plasma or in complete, heat-inactivated or sCD14-depleted serum. Moreover, cytokine production was no longer observed when rsCD14 was pretreated with thrombocytes. The thrombocyte effect was dose and time dependent. In conclusion, sCD14 is able to activate myeloid cells, and the effect is prevented by the presence of plasma, serum, or thrombocytes.
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Affiliation(s)
- R Landmann
- Department of Research, Medicine University Hospital, Basel, Switzerland
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33
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Link S. William James McGill (1922-1997). J Math Psychol 1998; 42:1-4. [PMID: 9606158 DOI: 10.1006/jmps.1998.1208] [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: 05/22/2023]
Abstract
Copyright
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Affiliation(s)
- S Link
- Link Psychophysical Laboratory Department of Psychology, McMaster University
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34
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Hurlebaus AE, Link S. The effects of an aggressive behavior management program on nurses' levels of knowledge, confidence, and safety. J Nurs Staff Dev 1997; 13:260-265. [PMID: 9362823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Violence in the workplace is increasing, and unfortunately, hospitals are not exempt from the problem. Nurses are the primary caregivers in hospitals and are more likely to encounter violence because of the amount of time spent in direct patient care. Many nurses have not been trained to manage explosive situations. This project was developed to provide a program titled, "Managing Aggressive Behavior," to nurses and to measure and compare the differences in levels of knowledge and feelings of safety and confidence among nurses who attended the workshop versus a group who did not. The data revealed a significant difference in knowledge in the program group (P < 0.001) but no significant changes in safety (P = 0.367) or confidence (P = 0.440). No significant changes were found among the variables in the treatment group. Suggestions for further research and teaching are given.
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Abstract
Monocyte phenotypes and functions were studied in 22 patients with major depression, and compared with those of 22 matched healthy controls. Immune measures were performed before and after dexamethasone suppression, and after 4 and 12 weeks of moclobemide therapy in patients. Seven patients terminated after 4 weeks because of treatment failure; 11 out of 15 patients responded to therapy after 12 weeks. Monocyte human leukocyte antigen class II and CD14 antigen expression, tumor necrosis factor production, and plasma interferon-gamma and neopterin did not differ in patients before treatment and controls. The reaction to dexamethasone was also similar in patients and controls. Neither antidepressive treatment per se nor the clinical response to it affected any immunological parameter. In conclusion, corticosteroid-controlled monocyte functions were similar in untreated and treated depressed patients and in controls, and unrelated to the clinical course of the disease.
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Affiliation(s)
- R Landmann
- Department of Research, University Hospital, Basel, Switzerland
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36
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Abstract
Membrane CD14 is involved in lipopolysaccharide (LPS)-induced monocyte activation; it binds LPS, and antibodies against CD14 block the effects of low-dose LPS. It is unknown how LPS regulates its own receptor CD14 in vitro. Therefore, we investigated the effects of LPS on CD14 mRNA and membrane and soluble CD14 (mCD14 and sCD14, respectively) in human monocytes and macrophages. No changes were observed during the first 3 h of LPS stimulation. After 6 to 15 h, LPS weakly reduced CD14 mRNA and mCD14 and transiently enhanced sCD14 release. A 2-day incubation with LPS caused increases in the levels of CD14 mRNA (2-fold), mCD14 (2-fold), sCD14 (1.5-fold), and LPS-fluorescein isothiocyanate binding (1.5-fold); a 5-h incubation with LPS was sufficient to induce the late effects on mCD14 and sCD14. The maximal effect on mCD14 and sCD14 was reached with > or = 1 ng of LPS per ml; the proportional distribution of the two sCD14 isoforms was not modified by LPS. Besides rough and smooth LPS, lipid A, heat-killed Escherichia coli, lipoteichoic acid, and Staphylococcus aureus cell wall extract (10 micrograms/ml) caused similar increases of mCD14. The LPS effect was blocked by polymyxin B but not by anti-tumor necrosis factor alpha, anti-interleukin-6, anti-gamma interferon, and anti-LPS-binding protein. LPS-induced tumor necrosis factor alpha production was abolished after a second 4-h challenge. In contrast, the LPS-induced increases CD14 mRNA, mCD14, and sCD14 were stronger and appeared earlier after a second LPS challenge. In conclusion, CD14 is transcriptionally upregulated by LPS and other bacterial cell wall constituents.
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Affiliation(s)
- R Landmann
- Department of Research and Internal Medicine, University Hospital, Basel, Switzerland
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37
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Landmann R, Scherer F, Schumann R, Link S, Sansano S, Zimmerli W. LPS directly induces oxygen radical production in human monocytes via LPS binding protein and CD14. J Leukoc Biol 1995; 57:440-9. [PMID: 7533819 DOI: 10.1002/jlb.57.3.440] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [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: 01/25/2023] Open
Abstract
In human monocytes, superoxide (O2-) generation accompanies phagocytosis and is important for bactericidal activity. It also contributes to tissue damage in inflammation. In the present study we investigated, whether lipopolysaccharide (LPS) directly stimulates monocyte O2- production with kinetics known for other LPS effects and, if so, by which mechanism. LPS caused a time- and dose-dependent O2- release in nonadherent purified monocytes. The effect appeared after 5 min, peaked at 30 min, and disappeared after 2 h. It was maximal with 10 ng/ml lipid A (+148 +/- 22%, P < .001), 1 ng/ml LPS Escherichia coli Re (+226 +/- 68%, P < .001), and 100 ng/ml LPS Salmonella abortus equi sm (+272 +/- 52%, P < .001), respectively. The effect was not observed in buffer, even when using 10 micrograms/ml LPS. It was dependent on the presence of heat-inactivated AB serum, with a maximal effect at > or = 0.5%. Serum could be replaced by LPS-binding protein (LBP). Polymyxin B and anti-LBP antiserum, respectively, blocked the LPS effect. LPS-induced O2- generation was also completely blocked by anti-CD14 antibodies (3C10 and 63D3) and by their corresponding F(ab')2 fragments. Monocytes treated with phosphoinositol-specific phospholipase C and monocytes from patients with paroxysmal nocturnal hemoglobinuria, lacking the phosphatidylinositol-anchored CD14, did not respond to LPS stimulation with O2- production. Similarly to LPS, E. coli caused stronger O2- production with heat-inactivated serum than without, and this effect was blocked by anti-CD14 antibodies. In conclusion, these data indicate that LPS directly stimulates O2- production in human monocytes via CD14 depending on LBP.
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Affiliation(s)
- R Landmann
- Department of Research, University Hospital, Basel, Switzerland
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Landmann R, Zimmerli W, Sansano S, Link S, Hahn A, Glauser MP, Calandra T. Increased circulating soluble CD14 is associated with high mortality in gram-negative septic shock. J Infect Dis 1995; 171:639-44. [PMID: 7533199 DOI: 10.1093/infdis/171.3.639] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.2] [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: 01/25/2023] Open
Abstract
The soluble glycoprotein sCD14 binds lipopolysaccharide, a complex that activates endothelial cells and that may be crucial in gram-negative sepsis. Therefore, serum sCD14 was analyzed in 54 patients with gram-negative septic shock and in 26 healthy controls. sCD14 was tested by ELISA and Western blotting. Patients had higher sCD14 concentrations than controls (median, 3.23 vs. 2.48 micrograms/mL, P = .002). Increased levels were associated with high mortality (median, 4.2 micrograms/mL in nonsurvivors vs. 2.8 micrograms/mL in survivors, P = .001). sCD14 was found in two isoforms (49 and 55 kDa) in monocyte cultures. In sera only one of either form was detectable. Controls had the 49-kDa form, and patients had either the 49- or 55-kDa form, but patients with high levels of sCD14 had only the 55-kDa form. Twenty-one (53%) of 39 with the 55-kDa form and 8 (57%) of 14 with the 49-kDa form died. Thus, the level of sCD14 but not its biochemical form had a prognostic value in patients with gram-negative septic shock.
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Affiliation(s)
- R Landmann
- Department of Research, University Hospital, Basel, Switzerland
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39
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Abstract
The effects of various inotropic interventions on post-rest potentiation and its decay were investigated in isolated cardiac muscle. The inotropic interventions studied were: reduced extracellular Na+ and elevated extracellular Ca2+ concentration; exposure to ouabain, monensin, isoprenaline, phenylephrine and cirazoline. Force of contraction (stimulation frequency 2 Hz) was measured isometrically in left atria and right ventricular strips of rat hearts. Maximum post-rest potentiation was reached after 10 sec. of rest and amounted to 245 +/- 26% of pre-rest control in ventricle and 192 +/- 15% in atria. Ca(2+)-recirculation fraction was calculated from the decay of post-rest potentiation after resumption of regular stimulation, it was 0.77 +/- 0.01 in 11 control ventricular strips. High concentrations of caffeine (3 mmol/l) completely abolished post-rest potentiation in both tissues. The development of post-rest potentiation was accelerated in the presence of most of the inotropic agents. However, with the exception of ouabain and only in atrial muscle, none of the inotropic interventions produced higher post-rest contraction amplitudes than during controls. In rat heart muscle, the inotropic interventions studied are not any more effective in augmenting force of contraction than prolonged stimulation intervals. This suggests that (1) the distribution of Ca2+ into the sarcoplasmic reticulum is at a maximum during post-rest potentiation; (2) modifications of signal transduction pathways cannot further increase post-rest potentiation; and therefore that (3) shifts in Ca2+ distribution act as a limiting factor.
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Affiliation(s)
- U Ravens
- Department of Pharmacology, University of Essen, Germany
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40
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Link S, Erné SN, Edrich J. Finite Element Solution of the Biomagnetic Forward Problem Using Automatically-Constructed Realistic Torso Models. BIOMED ENG-BIOMED TE 1994. [DOI: 10.1515/bmte.1994.39.s1.115] [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: 11/15/2022]
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41
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Miller RH, Paape MJ, Filep R, Link S. Flow cytometric analysis of neutrophils in cows' milk. Am J Vet Res 1993; 54:1975-9. [PMID: 8116925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Procedures were developed to count neutrophils in milk, using a flow cytometer. Milk samples from 2 experiments were counted: 1 with 4 noninfected cows and a second with 5 noninfected cows that were injected with endotoxin in 2 mammary quarters. Thus, the procedures were evaluated on normal milk and on that with high somatic cell count. Flow cytometric procedures involved fluorescence detection (from the dye carboxydimethylfluorescein diacetate) to distinguish intact and viable from fragmented cells, forward light scatter to detect cell size differences, and right-angle side scatter to detect cellular granularity. High fluorescence, large size, and high degree of granularity identified viable neutrophils. For all samples, neutrophils were also counted manually, using the cytologic centrifugation approach to create the slides; manual counts were used as the standard for comparison. In experiment 1 (normal milk), mean values for percentage of viable neutrophils estimated by manual and flow cytometry procedures agreed closely (26% vs 25.8% for foremilk and 28.8% vs 26.6% for bucket milk). Sources of variation in manual and flow cytometric estimates of percentage of neutrophils were examined. Cow variation was significant (P < 0.01) for manual and flow cytometric counts, but was larger for flow cytometric counts. Day-to-day variation in counts on milk from the same cow was negligible for manual counts, but was significant (P < 0.01) for flow cytometric counts.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R H Miller
- Milk Secretion and Mastitis Laboratory, USDA, Beltsville, MD 20705
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42
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Link S, Friedburg DZ, Wood BP. Radiological cases of the month. Pulmonary sling anomaly of the left pulmonary artery. Am J Dis Child 1993; 147:685-6. [PMID: 8506841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- S Link
- Department of Radiology, Medical College of Wisconsin, Milwaukee
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43
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Abstract
This paper presents the results of a survey of 43 occupational therapy academic programs regarding their preparation of students to work with young children with special needs. The number of instructional hours devoted to topics related to services for infants or toddlers and their families varied greatly. Some programs plan an increase in hours but are limited by the total hours available within the curriculum. This paper also shares the recommendations of a panel of occupational therapists with expertise in early intervention and entry-level education. The panel was concerned with the quality of preparation of therapists entering early intervention programs and encouraged the profession to review the amount of course work within each curriculum that introduces students to basic knowledge and skills related to early intervention. Some knowledge, such as the consultant's role and working with families of persons who are physically or mentally challenged, are common to other practice areas. The panel stressed that students be taught strategies for obtaining the training necessary for postgraduate entry into a specialty area such as early intervention.
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Affiliation(s)
- R Humphry
- Division of Occupational Therapy, University of North Carolina, Chapel Hill 27599-7120
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44
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Abstract
A rapidly proliferating T-cell line, HCD8, was derived from the peripheral blood lymphocytes of an apparently healthy individual during the course of a T-cell cloning experiment. This T-cell line expressed a very unusual phenotype: CD1+, CD2-, CD3+ (cytoplasmic), CD4-, CD5+, CD7+, CD8-, interleukin-2 receptor (IL-2 R) (p55)-, and T-cell antigen receptor (TCAR) alpha beta-. Assays for reverse transcriptase activity and for human T-lymphotropic retroviral sequences in the cellular DNA were negative, indicating that the cells were not transformed by human T-lymphotropic virus (HTLV)-I, HTLV-II, or human immunodeficiency virus (HIV)-I. Culturing the cells in the differentiation inducing agent 12-O-tetradecanoyl phorbol 13-acetate induced an increased expression of CD3 but no other significant changes in T-cell markers. A small population of CD4-negative and CD8-negative T-lymphocytes exist in human peripheral blood and they exhibit natural killer (NK) and antibody-dependent cell-mediated cytotoxic (ADCC) activity. However, the authors' cell line failed to demonstrate such cytotoxic function. The TCAR gene rearrangement studies showed that both T gamma genes were rearranged while the T beta genes were in the germ line configuration and the T delta genes were deleted. HCD8 strongly expressed the antigens Leu M1 and Ki-1, markers detected only rarely on normal unstimulated human T-cells, but quite consistently found on Reed-Sternberg cells and cells of some large pleomorphic T-cell lymphomas. HCD8 may be used to study the control of Leu M1 and Ki-1 expression in T-cells and it may provide some insight into the cellular origin of the above-mentioned lymphomas.
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Affiliation(s)
- W C Chan
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
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Nienartowicz A, Link S, Moll W. Adaptation of the uterine arcade in rats to pregnancy. J Dev Physiol 1989; 12:101-8. [PMID: 2621336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In order to study the adaptation of the uterine arterial system to pregnancy we measured vascular dimensions and other growth related data (DNA content and [3H]thymidine incorporation rate) on excised uterine arcades, pressurized to 100 mmHg, of rats before and during pregnancy (day 8, 18 and 21 of gestation). The vascular conductance of the arcade was calculated using a numerical method. In order to investigate the response of the arcade to flow impairment during early pregnancy, the same measurements were repeated on uterine arcades from pregnant animals (day 21 of gestation), where the left uterine artery had been ligated on day 8 of pregnancy. In adult virgin rats, the uterine arcade was 0.3 +/- 0.05 mm wide and 50 +/- 5 mm long. With these vascular dimensions the vascular conductance of the arcade (2.5 microliters/(s x mmHg] was calculated to be inadequate for the blood supply to the pregnant uterus at term. During the course of pregnancy modest changes were seen: The arcade increased 80% in length, 30% and 80% in internal diameter at the ovarian and cervical origin respectively and 6 times in conductance. Weight of the arcades increased 2-3-fold, [3H]thymidine incorporation rate 7-fold whereas the DNA mass remained constant. Ligation of the uterine artery on day 8 caused a 2 times increase in internal diameter of the ovarian (open) origin of the arcade without change in weight, whilst the cervical (ligated) origin of the arcade had the same internal diameter as that of the control group. The calculated vascular conductance of the ligated arcade was the same as for controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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Chan WC, Ye G, Link S, Mawle AC, Nicholson JK. CD2 and other surface molecules in the regulation of non-MHC-restricted cytolytic function. Immunology 1989; 67:56-61. [PMID: 2567703 PMCID: PMC1385288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The effect of anti-CD2 and Fc receptor binding molecules on the cytolytic function of a highly enriched population of CD3- large granular lymphocytes (LGL) was studied. These cells could mediate natural killer (NK) activity, antibody-dependent cellular cytotoxicity (ADCC) and lectin-dependent cellular cytotoxicity (LDCC). Both ADCC and LDCC were enhanced by anti-CD2. The enhanced LDCC could also be observed with IL-2-activated LGL. However, NK cell activity was usually slightly diminished or unaffected by anti-CD2 binding. Immune complex and aggregated human IgG had no effect on ADCC but an anti-CD16 showed a dose-dependent inhibition of ADCC, reversible by anti-HLA-ABC and anti-CD2. Cross-linking of LGL surface-bound anti-CD2 caused an almost complete inhibition of LDCC and ADCC but had much less effect on NK activity. These experiments show that ADCC and LDCC mediated by CD3- LGL can be influenced by perturbing the CD2 molecule. NK activity was, however, affected differently, suggesting some basic differences in the pathway of ADCC and NK function.
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Affiliation(s)
- W C Chan
- Emory University School of Medicine, Department of Pathology and Laboratory Medicine, Atlanta, Georgia 30322
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Chan WC, Dahl C, Waldmann T, Link S, Mawle A, Nicholson J, Bach FH, Bongiovanni K, McCue PA, Winton EF. Large granular lymphocyte proliferation: an analysis of T-cell receptor gene arrangement and expression and the effect of in vitro culture with inducing agents. Blood 1988; 71:52-8. [PMID: 2961380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The status of the T cell receptor beta and gamma genes in natural killer (NK) cells was investigated in two patients with a marked expansion of CD2+, CD3- NK cells. Both genes were found to be in the germline state. The T alpha and complete T beta gene transcripts were not detected, but a 1.0-kilobase T beta gene transcript could be demonstrated at low levels in freshly isolated cells and at a much higher level in interleukin-2 (IL-2)-cultured cells. The transcript coding for the delta chain of the CD3 complex was also absent. These cells were cultured in IL-2 with or without the addition of the differentiation-inducing agents: retinoic acid, N,N-hexamethylene bisacetamide, and sodium butyrate. The cultured cells retained their NK activity except in culture with sodium butyrate at greater than or equal to 1 mmol/L. Expression of CD3 or other T cell surface markers by the NK cells was not observed in these cultures. Either CD2+, CD3- NK cells are derived from a non-T lineage, or they have diverged from the T cell lineage earlier than the stage of T gamma gene rearrangement and CD3 delta chain expression; they are refractory to many induction signals in undergoing further T cell differentiation.
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Affiliation(s)
- W C Chan
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA
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Chan WC, Link S, Mawle A, Check I, Brynes RK, Winton EF. Heterogeneity of large granular lymphocyte proliferations: delineation of two major subtypes. Blood 1986; 68:1142-53. [PMID: 3490288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Two major types of lymphocytosis of large granular lymphocytes (LGLs) were observed. The proliferating LGLs in each type had distinct immunophenotypes, functional characteristics, and probably belonged to different cell lineages. The more common form (Type A) consisted of cells derived from the T cell lineage and had the T suppressor/cytotoxic phenotype (T11+, T3+, T8+). The expression of the Leu 7 and HLA-DR antigen was variable. These cells did not have natural killer (NK) function but showed a variable degree of antibody-dependent cell-mediated cytotoxic (ADCC) activity. Neutropenia was invariably present and rheumatoid arthritis and autoantibodies were frequent associations. These lymphocytes had many similarities to the major type of LGLs present in normal adult bone marrow. The other type of LGL lymphocytosis (Type B) consisted of cells lacking the antigens T3 and T8 but expressing M1 and NKH1. These cells possessed strong NK and ADCC activity but their cell lineage was not clear. Neutropenia and autoimmune phenomena were not detected. The cytochemical characteristics of the LGL granules from both types of patients were similar but differences in ultrastructure were observed. LGLs from Type B patients proliferated in the presence of Interleukin 2 (IL-2) and 12-O-tetradecanoyl-phorbol-13 acetate (TPA). Significant changes in their basic T11+, T3-, T8- phenotype were not observed. IL-2 and TPA, however, had profound influence on the NK function of the cells with enhancement in the case of IL-2 and marked suppression when stimulated by TPA.
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49
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Abstract
The illusion was obtained with artificial moons viewed against a luminous ceiling, and also with an imaginary ceiling induced by first showing a luminous ceiling and then removing it before the moons were introduced.
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