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  • 1
    Online-Ressource
    Online-Ressource
    Oxford :Oxford University Press, Incorporated,
    Schlagwort(e): Quantum theory. ; Electronic books.
    Beschreibung / Inhaltsverzeichnis: This is the second of two volumes on the genesis of quantum mechanics in the first quarter of the 20th century. It covers the rapid transition from the old to the new quantum theory in the years 1923-1927.
    Materialart: Online-Ressource
    Seiten: 1 online resource (817 pages)
    Ausgabe: 1st ed.
    ISBN: 9780198883913
    DDC: 530.1209
    Sprache: Englisch
    Anmerkung: Cover -- Titlepage -- Copyright -- Dedication -- Preface -- Contents -- List of Plates -- 8 Introduction to Volume 2 -- 8.1 Overview -- 8.2 Quantum theory in the early 1920s: deficiencies and discoveries (exclusion principle and spin) -- 8.3 Atomic structure à la Bohr, X-ray spectra, and the discovery of the exclusion principle -- 8.3.1 Important clues from X-ray spectroscopy -- 8.3.2 Electron arrangements and the emergence of the exclusion principle -- 8.3.3 The discovery of electron spin -- 8.4 The dispersion of light: a gateway to a new mechanics -- 8.4.1 The Lorentz-Drude theory of dispersion -- 8.4.2 Dispersion theory and the Bohr model -- 8.4.3 Final steps to a correct quantum dispersion formula -- 8.4.4 A generalized dispersion formula for inelastic light scattering-the Kramers-Heisenberg paper -- 8.5 The genesis of matrix mechanics -- 8.5.1 Intensities, and another look at the hydrogen atom -- 8.5.2 The Umdeutung paper -- 8.5.3 The new mechanics receives an algebraic framing-Born and Jordan's Two-Man-Paper -- 8.5.4 Dirac and the formal connection between classical and quantum mechanics -- 8.5.5 The Three-Man-Paper [Dreimännerarbeit]-completion of the formalism of matrix mechanics -- 8.6 The genesis of wave mechanics -- 8.6.1 The mechanical-optical route to quantum mechanics -- 8.6.2 Schrödinger's wave mechanics -- 8.7 The new theory repairs and extends the old -- 8.8 Statistical aspects of the new quantum formalisms -- 8.9 The Como and Solvay conferences, 1927 -- 8.10 Von Neumann puts quantum mechanics in Hilbert space -- Part III Transition to the New Quantum Theory -- 9 The Exclusion Principle and Electron Spin -- 9.1 The road to the exclusion principle -- 9.1.1 Bohr's second atomic theory -- 9.1.2 Clues from X-ray spectra -- 9.1.3 The filling of electron shells and the emergence of the exclusion principle. , 9.2 The discovery of electron spin -- 10 Dispersion Theory in the Old Quantum Theory -- 10.1 Classical theories of dispersion -- 10.1.1 Damped oscillations of a charged particle -- 10.1.2 Forced oscillations of a charged particle -- 10.1.3 The transmission of light: dispersion and absorption -- 10.1.4 The Faraday effect -- 10.1.5 The empirical situation up to ca. 1920 -- 10.2 Optical dispersion and the Bohr atom -- 10.2.1 The Sommerfeld-Debye theory -- 10.2.2 Dispersion theory in Breslau: Ladenburg and Reiche -- 10.3 The correspondence principle in radiation and dispersion theory: Van Vleck and Kramers -- 10.3.1 Van Vleck and the correspondence principle for emission and absorption of light -- 10.3.2 Dispersion in a classical general multiply periodic system -- 10.3.3 The Kramers dispersion formula -- 10.4 Intermezzo: the BKS theory and the Compton effect -- 10.5 The Kramers-Heisenberg paper and the Thomas-Reiche-Kuhn sum rule: on the verge of Umdeutung -- 11 Heisenberg's Umdeutung Paper -- 11.1 Heisenberg in Copenhagen -- 11.2 A return to the hydrogen atom -- 11.3 From Fourier components to transition amplitudes -- 11.4 A new quantization condition -- 11.5 Heisenberg's Umdeutung paper: a new kinematics -- 11.6 Heisenberg's Umdeutung paper: a new mechanics -- 12 The Consolidation of Matrix Mechanics: Born-Jordan, Dirac and the Three-Man-Paper -- 12.1 The ``Two-Man-Paper'' of Born and Jordan -- 12.2 The new theory derived differently: Dirac's formulation of quantum mechanics -- 12.3 The ``Three-Man-Paper'' of Born, Heisenberg, and Jordan -- 12.3.1 First chapter: systems of a single degree of freedom -- 12.3.2 Second chapter: foundations of the theory of systems of arbitrarily many degrees of freedom -- 12.3.3 Third chapter: connection with the theory of eigenvalues of Hermitian forms -- 12.3.4 Third chapter (cont'd): continuous spectra. , 12.3.5 Fourth chapter: physical applications of the theory -- 13 De Broglie's Matter Waves and Einstein's Quantum Theory of the Ideal Gas -- 13.1 De Broglie and the introduction of wave-particle duality -- 13.2 Wave interpretation of a particle in uniform motion -- 13.3 Classical extremal principles in optics and mechanics -- 13.4 De Broglie's mechanics of waves -- 13.5 Bose-Einstein statistics and Einstein's quantum theory of the ideal gas -- 14 Schrödinger and Wave Mechanics -- 14.1 Schrödinger: early work in quantum theory -- 14.2 Schrödinger and gas theory -- 14.3 The first (relativistic) wave equation -- 14.4 Four papers on non-relativistic wave mechanics -- 14.4.1 Quantization as an eigenvalue problem. Part I -- 14.4.2 Quantization as an eigenvalue problem. Part II -- 14.4.3 Quantization as an eigenvalue problem. Part III -- 14.4.4 Quantization as an eigenvalue problem. Part IV -- 14.5 The ``equivalence'' paper -- 14.6 Reception of wave mechanics -- 15 Successes and Failures of the Old Quantum Theory Revisited -- 15.1 Fine structure 1925-1927 -- 15.2 Intermezzo: Kuhn losses suffered and recovered -- 15.3 External field problems 1925-1927 -- 15.3.1 The anomalous Zeeman effect: matrix-mechanical treatment -- 15.3.2 The Stark effect: wave-mechanical treatment -- 15.4 The problem of helium -- 15.4.1 Heisenberg and the helium spectrum: degeneracy, resonance, and the exchange force -- 15.4.2 Perturbative attacks on the multi-electron problem -- 15.4.3 The helium ground state: perturbation theory gives way to variational methods -- Part IV The Formalism of Quantum Mechanics and Its Statistical Interpretation -- 16 Statistical Interpretation of Matrix and Wave Mechanics -- 16.1 Evolution of probability concepts from the old to the new quantum theory -- 16.2 The statistical transformation theory of Jordan and Dirac. , 16.2.1 Jordan's and Dirac's versions of the statistical transformation theory -- 16.2.2 Jordan's ``New foundation …'' I -- 16.2.3 Hilbert, von Neumann, and Nordheim on Jordan's ``New foundation …'' I -- 16.2.4 Jordan's ``New foundation …'' II -- 16.3 Heisenberg's uncertainty relations -- 16.4 Como and Solvay, 1927 -- 17 Von Neumann's Hilbert Space Formalism -- 17.1 ``Mathematical foundation …'' -- 17.2 ``Probability-theoretic construction …'' -- 17.3 From canonical transformations to transformations in Hilbert space -- 18 Conclusion: Arch and Scaffold -- 18.1 Continuity and discontinuity in the quantum revolution -- 18.2 Continuity and discontinuity in two early quantum textbooks -- 18.3 The inadequacy of Kuhn's model of a scientific revolution -- 18.4 Evolution of species and evolution of theories -- 18.5 The role of constraints in the quantum revolution -- 18.6 Limitations of the arch-and-scaffold metaphor -- 18.7 Substitution and generalization -- Appendix -- C C. The Mathematics of Quantum Mechanics -- C.1 Matrix algebra -- C.2 Vector spaces (finite dimensional) -- C.3 Inner-product spaces (finite dimensional) -- C.4 A historical digression: integral equations and quadratic forms -- C.5 Infinite-dimensional spaces -- C.5.1 Topology: open and closed sets, limits, continuous functions, compact sets -- C.5.2 The first Hilbert space: l2 -- C.5.3 Function spaces: L2 -- C.5.4 The axiomatization of Hilbert space -- C.5.5 A new notation: Dirac's bras and kets -- C.5.6 Operators in Hilbert space: von Neumann's spectral theory -- Bibliography -- Index.
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  • 2
    Online-Ressource
    Online-Ressource
    Oxford :Oxford University Press, Incorporated,
    Schlagwort(e): Quantum field theory. ; Electronic books.
    Beschreibung / Inhaltsverzeichnis: The book provides a step by step construction of the framework of relativistic quantum field theory, starting from a minimal set of basic foundational postulates. The emphasis is on a careful and detailed description of the conceptual subtleties of modern field theory, many of which are glossed over in other texts.
    Materialart: Online-Ressource
    Seiten: 1 online resource (793 pages)
    Ausgabe: 1st ed.
    ISBN: 9780191642203
    DDC: 530.143
    Sprache: Englisch
    Anmerkung: Cover -- Contents -- 1 Origins I: From the arrow of time to the first quantum field -- 1.1 Quantum prehistory: crises in classical physics -- 1.2 Early work on cavity radiation -- 1.3 Planck's route to the quantization of energy -- 1.4 First inklings of field quantization: Einstein and energy fluctuations -- 1.5 The first true quantum field: Jordan and energy fluctuations -- 2 Origins II: Gestation and birth of interacting field theory: from Dirac to Shelter Island -- 2.1 Introducing interactions: Dirac and the beginnings of quantum electrodynamics -- 2.2 Completing the formalism for free fields: Jordan, Klein, Wigner, Pauli, and Heisenberg -- 2.3 Problems with interacting fields: infinite seas, divergent integrals, and renormalization -- 3 Dynamics I: The physical ingredients of quantum field theory: dynamics, symmetries, scales -- 4 Dynamics II: Quantum mechanical preliminaries -- 4.1 The canonical (operator) framework -- 4.2 The functional (path-integral) framework -- 4.3 Scattering theory -- 4.4 Problems -- 5 Dynamics III: Relativistic quantum mechanics -- 5.1 The Lorentz and Poincaré groups -- 5.2 Relativistic multi-particle states (without spin) -- 5.3 Relativistic multi-particle states (general spin) -- 5.4 How not to construct a relativistic quantum theory -- 5.5 A simple condition for Lorentz-invariant scattering -- 5.6 Problems -- 6 Dynamics IV: Aspects of locality: clustering, microcausality, and analyticity -- 6.1 Clustering and the smoothness of scattering amplitudes -- 6.2 Hamiltonians leading to clustering theories -- 6.3 Constructing clustering Hamiltonians: second quantization -- 6.4 Constructing a relativistic, clustering theory -- 6.5 Local fields, non-localizable particles! -- 6.6 From microcausality to analyticity -- 6.7 Problems -- 7 Dynamics V: Construction of local covariant fields. , 7.1 Constructing local, Lorentz-invariant Hamiltonians -- 7.2 Finite-dimensional representations of the homogeneous Lorentz group -- 7.3 Local covariant fields for massive particles of any spin: the Spin-Statistics theorem -- 7.4 Local covariant fields for spin-& -- #189 -- (spinor fields) -- 7.5 Local covariant fields for spin-1 (vector fields) -- 7.6 Some simple theories and processes -- 7.7 Problems -- 8 Dynamics VI: The classical limit of quantum fields -- 8.1 Complementarity issues for quantum fields -- 8.2 When is a quantum field "classical"? -- 8.3 Coherent states of a quantum field -- 8.4 Signs, stability, symmetry-breaking -- 8.5 Problems -- 9 Dynamics VII: Interacting fields: general aspects -- 9.1 Field theory in Heisenberg representation: heuristics -- 9.2 Field theory in Heisenberg representation: axiomatics -- 9.3 Asymptotic formalism I: the Haag-Ruelle scattering theory -- 9.4 Asymptotic formalism II: the Lehmann-Symanzik-Zimmermann (LSZ) theory -- 9.5 Spectral properties of field theory -- 9.6 General aspects of the particle-field connection -- 9.7 Problems -- 10 Dynamics VIII: Interacting fields: perturbative aspects -- 10.1 Perturbation theory in interaction picture and Wick's theorem -- 10.2 Feynman graphs and Feynman rules -- 10.3 Path-integral formulation of field theory -- 10.4 Graphical concepts: N-particle irreducibility -- 10.5 How to stop worrying about Haag's theorem -- 10.6 Problems -- 11 Dynamics IX: Interacting fields: non-perturbative aspects -- 11.1 On the (non-)convergence of perturbation theory -- 11.2 "Perturbatively non-perturbative" processes: threshhold bound states -- 11.3 "Essentially non-perturbative" processes: non-Borel-summability in field theory -- 11.4 Problems -- 12 Symmetries I: Continuous spacetime symmetry: why we need Lagrangians in field theory. , 12.1 The problem with derivatively coupled theories: seagulls, Schwinger terms, and T* products -- 12.2 Canonical formalism in quantum field theory -- 12.3 General condition for Lorentz-invariant field theory -- 12.4 Noether's theorem, the stress-energy tensor, and all that stuff -- 12.5 Applications of Noether's theorem -- 12.6 Beyond Poincaré: supersymmetry and superfields -- 12.7 Problems -- 13 Symmetries II: Discrete spacetime symmetries -- 13.1 Parity properties of a general local covariant field -- 13.2 Charge-conjugation properties of a general local covariant field -- 13.3 Time-reversal properties of a general local covariant field -- 13.4 The TCP and Spin-Statistics theorems -- 13.5 Problems -- 14 Symmetries III: Global symmetries in field theory -- 14.1 Exact global symmetries are rare! -- 14.2 Spontaneous breaking of global symmetries: the Goldstone theorem -- 14.3 Spontaneous breaking of global symmetries: dynamical aspects -- 14.4 Problems -- 15 Symmetries IV: Local symmetries in field theory -- 15.1 Gauge symmetry: an example in particle mechanics -- 15.2 Constrained Hamiltonian systems -- 15.3 Abelian gauge theory as a constrained Hamiltonian system -- 15.4 Non-abelian gauge theory: construction and functional integral formulation -- 15.5 Explicit quantum-breaking of global symmetries: anomalies -- 15.6 Spontaneous symmetry-breaking in theories with a local gauge symmetry -- 15.7 Problems -- 16 Scales I: Scale sensitivity of .eld theory amplitudes and effective field theories -- 16.1 Scale separation as a precondition for theoretical science -- 16.2 General structure of local effective Lagrangians -- 16.3 Scaling properties of effective Lagrangians: relevant, marginal, and irrelevant operators -- 16.4 The renormalization group -- 16.5 Regularization methods in field theory -- 16.6 Effective field theories: a compendium -- 16.7 Problems. , 17 Scales II: Perturbatively renormalizable field theories -- 17.1 Weinberg's power-counting theorem and the divergence structure of Feynman integrals -- 17.2 Counterterms, subtractions, and perturbative renormalizability -- 17.3 Renormalization and symmetry -- 17.4 Renormalization group approach to renormalizability -- 17.5 Problems -- 18 Scales III: Short-distance structure of quantum field theory -- 18.1 Local composite operators in field theory -- 18.2 Factorizable structure of field theory amplitudes: the operator product expansion -- 18.3 Renormalization group equations for renormalized amplitudes -- 18.4 Problems -- 19 Scales IV: Long-distance structure of quantum field theory -- 19.1 The infrared catastrophe in unbroken abelian gauge theory -- 19.2 The Bloch-Nordsieck resolution -- 19.3 Unbroken non-abelian gauge theory: confinement -- 19.4 How confinement works: three-dimensional gauge theory -- 19.5 Problems -- Appendix A: The functional calculus -- Appendix B: Rates and cross-sections -- Appendix C: Majorana spinor algebra -- References -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- U -- V -- W -- Y -- Z.
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  • 3
    Online-Ressource
    Online-Ressource
    Oxford :Oxford University Press, Incorporated,
    Schlagwort(e): Quantum theory. ; Electronic books.
    Beschreibung / Inhaltsverzeichnis: This is the first of two volumes on the genesis of quantum mechanics, based on the latest scholarship in the field. This first volume covers the key developments in the field in the period between 1900-1923, which provided the scaffold on which modern quantum mechanics was built on.
    Materialart: Online-Ressource
    Seiten: 1 online resource (512 pages)
    Ausgabe: 1st ed.
    ISBN: 9780192584229
    DDC: 530.12
    Sprache: Englisch
    Anmerkung: Cover -- CONSTRUCTING QUANTUM MECHANICS -- Copyright -- Preface -- Contents -- List of plates -- Chapter 1 Introduction to Volume One -- 1.1 Overview -- 1.2 Early developments: Planck, Einstein, and Bohr -- 1.2.1 Planck, the second law, and black-body radiation -- 1.2.2 Planck's first tenuous steps toward energy quantization -- 1.2.3 Einstein, equipartition, and light quanta -- 1.2.4 Einstein, fluctuations, and light quanta -- 1.2.5 Lorentz convinces Planck of energy quantization -- 1.2.6 From Einstein, equipartition, and specific heat to Nernst and the Solvay conference -- 1.2.7 Bohr and Rutherford's model of the atom -- 1.2.8 Bohr and Nicholson's theory -- 1.2.9 The Balmer formula and the birth of the Bohr model of the atom -- 1.2.10 Einstein and the Bohr model -- 1.3 The old quantum theory: principles, successes, and failures -- 1.3.1 Sommerfeld's path to quantum theory -- 1.3.2 Quantum conditions: Planck, Sommerfeld, Ishiwara, Wilson, Schwarzschild, and Epstein -- 1.3.3 Ehrenfest and the adiabatic principle -- 1.3.4 The correspondence principle from Bohr to Kramers, Born, and Van Vleck -- 1.3.5 The old quantum theory's winning streak: fine structure, Stark effect, X-ray spectra -- 1.3.6 The old quantum theory's luck runs out:multiplets, Zeeman effect, helium -- 1.3.7 Born taking stock -- Part I Early Developments -- Chapter 2 Planck, the Second Law of Thermodynamics, and Black-body Radiation -- 2.1 The birthdate of quantum theory? -- 2.2 Early work on black-body radiation (1860-1896) -- 2.3 Planck, the second law of thermodynamics, and black-body radiation (1895-1899) -- 2.4 From the Wien law to the Planck law: changing the expression for the entropy of a resonator -- 2.5 Justifying the new expression for the entropy of a resonator -- 2.6 Energy parcels or energy bins? -- Chapter 3 Einstein, Equipartition, Fluctuations, and Quanta. , 3.1 Einstein's annus mirabilis -- 3.2 The statistical trilogy (1902-1904) -- 3.3 The light-quantum paper (1905) -- 3.3.1 Classical theory leads to the Rayleigh-Jeans law -- 3.3.2 Einstein's argument for light quanta: fluctuations in black-body radiation at high frequencies -- 3.3.3 Evidence for light quanta: the photoelectric effect -- 3.4 Black-body radiation and the necessity of quantization -- 3.4.1 The quantization of Planck's resonators -- 3.4.2 Lorentz's 1908 Rome lecture: Planck versus Rayleigh-Jeans -- 3.4.3 Einstein's 1909 Salzburg lecture: fluctuations and wave-particle duality -- 3.5 The breakdown of equipartition and the specific heat of solids at low temperatures (1907-1911) -- 3.6 Einstein's quantum theory of radiation (1916) -- 3.6.1 New derivation of the Planck law -- 3.6.2 Momentum fluctuations and the directed nature of radiation -- Chapter 4 The Birth of the Bohr Model -- 4.1 Introduction -- 4.2 The dissertation: recognition of problems of classical theory -- 4.3 The Rutherford Memorandum: atomic models and quantum theory -- 4.3.1 Prelude: classical atomic models (Thomson, Nagaoka, Schott) -- 4.3.2 Scattering of α particles and Rutherford's nuclear atom -- 4.3.3 Bohr's first encounter with Rutherford's nuclear atom: energy loss of α particles traveling through matter -- 4.3.4 Interlude: Planck's constant enters atomic modeling (Haas, Nicholson) -- 4.3.5 Planck's constant enters Bohr's atomic modeling -- 4.4 From the Rutherford Memorandum to the Trilogy -- 4.4.1 Bohr comparing his results to Nicholson's -- 4.4.2 Enter the Balmer formula -- 4.5 The Trilogy: quantum atomic models and spectra -- 4.5.1 Part One: the hydrogen atom -- 4.5.2 Parts Two and Three: multi-electron atoms and multi-atom molecules -- 4.6 Early evidence for the Bohr model: spectral lines in hydrogen and helium -- Part II The Old Quantum Theory. , Chapter 5 Guiding Principles -- 5.1 Quantization conditions -- 5.1.1 Planck -- 5.1.2 Wilson and Ishiwara -- 5.1.3 Sommerfeld -- 5.1.4 Schwarzschild, Epstein, and (once again) Sommerfeld -- 5.1.5 Einstein -- 5.2 The adiabatic principle -- 5.2.1 Ehrenfest's early work on adiabatic invariants -- 5.2.2 Ehrenfest's 1916 paper on the adiabatic principle -- 5.2.3 The adiabatic principle in Bohr's 1918 paper -- 5.2.4 Sommerfeld's attitude to the adiabatic principle -- 5.3 The correspondence principle -- Chapter 6 Successes -- 6.1 Fine structure -- 6.2 X-ray spectra -- 6.3 The Stark effect -- Chapter 7 Failures -- 7.1 The complex structure of spectral multiplets -- 7.1.1 Sommerfeld on multiplets -- 7.1.2 Heisenberg's core model and multiplets -- 7.2 The anomalous Zeeman effect -- 7.2.1 The Lorentz theory of the normal Zeeman effect -- 7.2.2 Anomalous Zeeman effect: experimental results and pre-Bohr theoretical interpretations -- 7.2.3 The Paschen-Back transmutation of Zeeman lines -- 7.3 The Zeeman effect in the old quantum theory -- 7.3.1 First steps (1913-1919) -- 7.3.2 Empirical regularities and number mysticism (1919-1921) -- 7.3.3 Core models, unmechanical forces, and double-valuedness -- 7.4 The problem of helium -- Appendices -- A Classical Mechanics -- A.1 The physicist's mechanical toolbox (ca 1915) -- A.1.1 Newtonian mechanics -- A.1.2 Lagrangian mechanics -- A.1.3 Hamiltonian mechanics -- A.1.4 The adiabatic principle -- A.2 The astronomer's mechanical toolbox (ca 1915) -- A.2.1 Hamilton-Jacobi theory -- A.2.2 Poisson brackets -- A.2.3 Action-angle variables -- A.2.4 Canonical perturbation theory -- B Spectroscopy -- B.1 Early quantitative spectroscopy -- B.2 Kirchhoff's Laws -- B.3 Technological advances and the emergence of analytic spectroscopy -- B.4 The numerology of spectra: Balmer and Rydberg -- B.5 The Zeeman effect. , B.6 A troublesome red herring -- B.7 Ritz and the combination principle -- Bibliography -- Index.
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  • 4
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 5653-5661 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Techniques of lattice field theory are utilized to compute the free energy of a system of fixed charged macroions surrounded by small (atomic size) mobile ions. The grand partition function for the simple ions is written down as a functional integral over a three-dimensional auxiliary field. This functional integral is discretized on a lattice, and then subjected to saddle point analysis. The lowest order or "mean field'' result of the analysis isolates a field which satisfies the Poisson–Boltzmann equation, and from which the Helmholtz free energy can be extracted. The formalism also provides a minimum principle for the Poisson–Boltzmann field that can be realized numerically by elementary annealing techniques. Most importantly, the mean field approximation can be systematically corrected by evaluating fluctuations around the saddle point to successive orders in an appropriate interaction strength. It is shown by numerical tests on a two-macroion system that the hierarchy of corrections converges rapidly in experimentally interesting regions of parameter space.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 4584-4594 
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: A recently proposed lattice field theory approach to the statistical mechanics of a classical Coulomb gas [J. Chem. Phys. 97, 5653 (1992)] is generalized to treat gas particles of finite size. To do this, a repulsive Yukawa interaction between all pairs of gas particles is added to the usual pairwise Coulombic interactions of the gas particles with each other and also with an arbitrary collection of immobile charges. Such a model is directly relevant for understanding the energetics of systems composed of macroions in electrolytic solutions when the simple ions that comprise the electrolyte are sufficiently large. A field theoretic representation of the grand partition function for the modified Coulomb gas is derived. Two coupled three-dimensional scalar fields are involved. Physically, one is related to the electrostatic potential and the other to the Yukawa potential. The field theory expression, once discretized onto an appropriate lattice, can be evaluated via saddle point expansion. The zeroth order or mean field approximation is found to be analogous to the Poisson–Boltzmann equation in the simple (infinitesimal particle) Coulomb gas problem. Higher order corrections can be obtained via a loop expansion procedure. Successful numerical application is reported for systems consisting of two spherical, equally charged macroions immersed in an electrolytic solution. Imbuing the simple ions in the solution with finite size prevents the degree of polarization of the ion cloud which is found in the infinitesimal ion limit. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
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  • 6
    Publikationsdatum: 2024-02-07
    Beschreibung: Zinc is an essential trace metal for oceanic primary producers with the highest concentrations in polar oceans. However, its role in the biological functioning and adaptive evolution of polar phytoplankton remains enigmatic. Here, we have applied a combination of evolutionary genomics, quantitative proteomics, co-expression analyses and cellular physiology to suggest that model polar phytoplankton species have a higher demand for zinc because of elevated cellular levels of zinc-binding proteins. We propose that adaptive expansion of regulatory zinc-finger protein families, co-expanded and co-expressed zinc-binding proteins families involved in photosynthesis and growth in these microalgal species and their natural communities were identified to be responsible for the higher zinc demand. The expression of their encoding genes in eukaryotic phytoplankton metatranscriptomes from pole-to-pole was identified to correlate not only with dissolved zinc concentrations in the upper ocean but also with temperature, suggesting that environmental conditions of polar oceans are responsible for an increased demand of zinc. These results suggest that zinc plays an important role in supporting photosynthetic growth in eukaryotic polar phytoplankton and that this has been critical for algal colonization of low-temperature polar oceans.
    Materialart: Article , PeerReviewed
    Format: text
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  • 7
    Publikationsdatum: 2015-08-12
    Beschreibung: Direct application of histone-deacetylase-inhibitors (HDACis) to dental pulp cells (DPCs) induces chromatin changes, promoting gene expression and cellular-reparative events. We have previously demonstrated that HDACis (Valproic acid, Trichostatin A) increase mineralization in dental papillae-derived cell-lines and primary DPCs by stimulation of dentinogenic gene expression. Here, we investigated novel genes regulated by the HDACi, suberoylanilide hydroxamic acid (SAHA), to identify new pathways contributing to DPC differentiation. SAHA significantly compromised DPC viability only at relatively high concentrations (5 μM); while low concentrations (1 μM) SAHA did not increase apoptosis. HDACi-exposure for 24 h induced mineralization-per-cell dose-dependently after 2 weeks; however, constant 14d SAHA-exposure inhibited mineralization. Microarray analysis (24 h and 14d) of SAHA exposed cultures highlighted that 764 transcripts showed a significant 〉2.0-fold change at 24 h, which reduced to 36 genes at 14d. 59% of genes were down-regulated at 24 h and 36% at 14d, respectively. Pathway analysis indicated SAHA increased expression of members of the matrix metalloproteinase (MMP) family. Furthermore, SAHA-supplementation increased MMP-13 protein expression (7d, 14 d) and enzyme activity (48 h, 14d). Selective MMP-13-inhibition (MMP-13i) dose-dependently accelerated mineralization in both SAHA-treated and non-treated cultures. MMP-13i-supplementation promoted expression of several mineralization-associated markers, however, HDACi-induced cell migration and wound healing were impaired. Data demonstrate that short-term low-dose SAHA-exposure promotes mineralization in DPCs by modulating gene pathways and tissue proteases. MMP-13i further increased mineralization-associated events, but decreased HDACi cell migration indicating a specific role for MMP-13 in pulpal repair processes. Pharmacological inhibition of HDAC and MMP may provide novel insights into pulpal repair processes with significant translational benefit. This article is protected by copyright. All rights reserved
    Digitale ISSN: 1097-4652
    Thema: Biologie , Medizin
    Publiziert von Wiley-Blackwell
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