ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Polymer and Materials Science  (7.785)
  • Life and Medical Sciences  (1.781)
  • ENERGY PRODUCTION AND CONVERSION
  • Physics
  • 2020-2024  (35)
  • 2010-2014  (7)
  • 1980-1984  (8.206)
  • 1955-1959  (1.989)
  • 1950-1954
  • 2021  (34)
  • 2020  (1)
  • 2010  (7)
  • 1984  (4.244)
  • 1983  (3.962)
  • 1959  (1.174)
  • 1957  (815)
Sammlung
Sprache
Erscheinungszeitraum
  • 2020-2024  (35)
  • 2010-2014  (7)
  • 1980-1984  (8.206)
  • 1955-1959  (1.989)
  • 1950-1954
  • +
Jahr
  • 1
    Unbekannt
    Amsterdam ; New York : North-Holland Pub. Co
    Schlagwort(e): DDC 530.1 ; LC QC20 ; Mathematical physics ; Physics ; Quantum theory ; Relativity (Physics)
    ISBN: 9780444875853
    Sprache: Englisch
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    facet.materialart.
    Unbekannt
    Springer Nature | Springer International Publishing
    Publikationsdatum: 2024-04-05
    Beschreibung: This Open Access book gives a comprehensive account of both the history and current achievements of molecular beam research. In 1919, Otto Stern launched the revolutionary molecular beam technique. This technique made it possible to send atoms and molecules with well-defined momentum through vacuum and to measure with high accuracy the deflections they underwent when acted upon by transversal forces. These measurements revealed unforeseen quantum properties of nuclei, atoms, and molecules that became the basis for our current understanding of quantum matter. This volume shows that many key areas of modern physics and chemistry owe their beginnings to the seminal molecular beam work of Otto Stern and his school. Written by internationally recognized experts, the contributions in this volume will help experienced researchers and incoming graduate students alike to keep abreast of current developments in molecular beam research as well as to appreciate the history and evolution of this powerful method and the knowledge it reveals.
    Schlagwort(e): Quantum Physics ; Atomic/Molecular Structure and Spectra ; Astronomy, Astrophysics and Cosmology ; History and Philosophical Foundations of Physics ; Physics, general ; Atomic and Molecular Structure and Properties ; History of Physics and Astronomy ; Philosophical Foundations of Physics and Astronomy ; Physics and Astronomy ; Open Access ; Molecular Beam History ; Precision Measurements ; Femto- and Atto-science ; Foundations of Quantum Mechanics ; Droplet Beams ; Molecular Beam Applications ; Matter Wave Interferometry ; Ultracold Atoms ; Quantum physics (quantum mechanics & quantum field theory) ; Nuclear physics ; Theoretical & mathematical astronomy ; History of science ; Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PG Astronomy, space and time ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-04
    Beschreibung: Eine lernendenorientierte und adaptive Gestaltung von Unterricht erfordert von den Lehrkräften, dass sie vorhandene Kompetenzen und Lernprozesse der Schülerinnen und Schüler diagnostizieren. Außerdem müssen sie die Anforderungen von Aufgaben mit Blick auf deren Passung zu den Lernprozessen der Schülerinnen und Schüler analysieren können. Eine derart verstandene "diagnostische Kompetenz" wird als zentrales Professionalisierungsziel von Lehrkräften angesehen. Vor diesem Hintergrund wurden die diagnostischen Prozesse von acht Studierenden mit den Fächern Physik und Mathematik in zwei aufeinander folgenden Lehrveranstaltungen zur Diagnostik untersucht, um Potentiale und Lernhindernisse im Kompetenzaufbau zu identifizieren. In beiden Veranstaltungen bildeten Vignetten von Lernprozessen den Ausgangspunkt für studentische Diagnosen. Forschungsgegenstand waren u.a. schriftliche Diagnosen der Studierenden im Prä-Post-Vergleich sowie auf Video aufgezeichnete studentische Diskurse bei der Diagnose von Lernprozessen der Schülerinnen und Schüler. Die Analysen erfassen u.a., auf welche Komponenten eines Diagnoseprozesses die Studierenden in welcher Weise Bezug nehmen und welche (fach-) didaktischen überlegungen bzw. Theoriebezüge sie in ihren Diagnosen als Referenzpunkte nutzen. Die Ergebnisse zeigen, dass auf struktureller Ebene zwar alle Komponenten thematisiert, aber inhaltlich nicht entlang einer typischen Abfolge miteinander verbunden werden. Trotz inhaltlicher Prompts wird nur selten explizit auf Theoriebezüge zurückgegriffen.
    Schlagwort(e): Mathematics ; Education ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PB Mathematics ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Deutsch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Publikationsdatum: 2021-02-10
    Beschreibung: This open access report explores the nature and extent of students’ misconceptions and misunderstandings related to core concepts in physics and mathematics and physics across grades four, eight and 12. Twenty years of data from the IEA’s Trends in International Mathematics and Science Study (TIMSS) and TIMSS Advanced assessments are analyzed, specifically for five countries (Italy, Norway, Russian Federation, Slovenia, and the United States) who participated in all or almost all TIMSS and TIMSS Advanced assessments between 1995 and 2015. The report focuses on students’ understandings related to gravitational force in physics and linear equations in mathematics. It identifies some specific misconceptions, errors, and misunderstandings demonstrated by the TIMSS Advanced grade 12 students for these core concepts, and shows how these can be traced back to poor foundational development of these concepts in earlier grades. Patterns in misconceptions and misunderstandings are reported by grade, country, and gender. In addition, specific misconceptions and misunderstandings are tracked over time, using trend items administered in multiple assessment cycles. The study and associated methodology may enable education systems to help identify specific needs in the curriculum, improve inform instruction across grades and also raise possibilities for future TIMSS assessment design and reporting that may provide more diagnostic outcomes.
    Schlagwort(e): Education ; International education  ; Comparative education ; Assessment ; Science education ; Mathematics ; Physics ; bic Book Industry Communication::J Society & social sciences::JN Education ; bic Book Industry Communication::J Society & social sciences::JN Education::JNK Organization & management of education::JNKD Examinations & assessment ; bic Book Industry Communication::J Society & social sciences::JN Education::JNU Teaching of a specific subject ; bic Book Industry Communication::P Mathematics & science::PB Mathematics ; bic Book Industry Communication::P Mathematics & science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Publikationsdatum: 2024-04-05
    Beschreibung: Volume 2 of this revised and updated edition provides an accessible and practical introduction to the two non-Abelian quantum gauge field theories of the Standard Model of particle physics: quantum chromodynamics (QCD) and the Glashow-Salam-Weinberg (GSW) electroweak theory.This volume covers much of the experimental progress made in the last ten y
    Schlagwort(e): Nuclear physics ; Physics ; Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory)
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    facet.materialart.
    Unbekannt
    World Scientific Publishing Company | World Scientific
    Publikationsdatum: 2024-04-05
    Beschreibung: This book provides a broad introduction to gauge field theories formulated on a space-time lattice, and in particular of QCD. It serves as a textbook for advanced graduate students, and also provides the reader with the necessary analytical and numerical techniques to carry out research on his own. Although the analytic calculations are sometimes quite demanding and go beyond an introduction, they are discussed in sufficient detail, so that the reader can fill in the missing steps. The book also introduces the reader to interesting problems which are currently under intensive investigation. Whenever possible, the main ideas are exemplified in simple models, before extending them to realistic theories. Special emphasis is placed on numerical results obtained from pioneering work. These are displayed in a great number of figures. Beyond the necessary amendments and slight extensions of some sections in the third edition, the fourth edition includes an expanded section on Calorons — a subject which has been under intensive investigation during the last twelve years.
    Schlagwort(e): Physics ; Particle Physics/high Energy Physics, Quantum Fields ; thema EDItEUR::P Mathematics and Science::PH Physics::PHU Mathematical physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Publikationsdatum: 2024-04-04
    Beschreibung: Physics
    Schlagwort(e): Physics ; bic Book Industry Communication::P Mathematics & science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-04
    Beschreibung: In this book, the author convinces that Sir Arthur Stanley Eddington had things a little bit wrong, as least as far as physics is concerned. He explores the theory of groups and Lie algebras and their representations to use group representations as labor-saving tools.
    Schlagwort(e): Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-05
    Beschreibung: A unified theory embracing all physical phenomena is a major goal of theoretical physics. In the early 1980s, many physicists looked to eleven-dimensional supergravity in the hope that it might provide that elusive superunified theory. In 1984 supergravity was knocked off its pedestal by ten-dimensional superstrings, one-dimensional objects whose v
    Schlagwort(e): Nuclear physics ; Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-05
    Beschreibung: This book provides a thorough introduction to the phenomenology of heavy flavour physics, those working on the B-factories, LHCb, BTeV, HERA and the Tevatron. It explains how heavy quark theory could be implemented on the lattice, and discusses the status of CP-violation in the neutral kaon system.
    Schlagwort(e): Nuclear physics ; Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 11
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-07
    Beschreibung: Climate Change; Energy Efficiency; Remote Sensing; Photogrammetry; Physics
    Schlagwort(e): Climate Change ; Energy Efficiency ; Remote Sensing ; Photogrammetry ; Physics ; thema EDItEUR::K Economics, Finance, Business and Management::KC Economics::KCV Economics of specific sectors::KCVG Environmental economics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHH Thermodynamics and heat
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 12
    facet.materialart.
    Unbekannt
    De Gruyter | De Gruyter
    Publikationsdatum: 2024-04-05
    Beschreibung: With applications in quantum field theory, general relativity and elementary particle physics, this three-volume work studies the invariance of differential operators under Lie algebras, quantum groups and superalgebras. This second volume covers quantum groups in their two main manifestations: quantum algebras and matrix quantum groups. The exposition covers both the general aspects of these and a great variety of concrete explicitly presented examples. The invariant q-difference operators are introduced mainly using representations of quantum algebras on their dual matrix quantum groups as carrier spaces. This is the first book that covers the title matter applied to quantum groups.
    Schlagwort(e): Science ; Physics ; Quantum Theory ; Mathematics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PB Mathematics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 13
    Publikationsdatum: 2024-03-29
    Beschreibung: Niedrige Studienerfolgsquoten in den Studiengängen Physik und Lehramt Physik sind sowohl aus bildungspolitischer und institutioneller Sicht als auch aus individueller Perspektive erfolglos Studierender eine Herausforderung. Bisher gibt es nur wenige empirische Studien, die Gründe für niedrige Studienerfolgsquoten bestimmen. Von dieser Situation ausgehend, zielte diese Arbeit auf die Erfassung domänenspezifischer Eingangsvoraussetzungen von Studienanfängerinnen und -anfängern, um daraus mögliche Prädiktoren für einen Studienerfolg zu bestimmen. Den Kern der Arbeit bildet die Konzeption und Evaluation eines Testinstruments zu Studieneingangsvoraussetzungen. Das Instrument umfasst einen Vorwissenstest in Mathematik und Physik sowie einen Test zu domänenspezifischen Verhaltensweisen und Einstellungen. Das selbstentwickelte Instrument wurde bei N = 116 Studierenden eingesetzt, um die Prognosekraft der gemessenen Konstrukte auf einen möglichen Studienerfolg zu schätzen. Dabei zeigte sich der Physikteil des Vorwissenstests in Verbindung mit der Hochschulzugangsberechtigungsnote als signifikanter Prädiktor für den Studienerfolg gemessen am Studienverbleib nach drei Semestern. Dieses Ergebnis stellt im Wesentlichen eine Replikation bereits bekannter Erkenntnisse dar. Es konnten erste Hinweise gefunden werden, dass sich lernzielorientierte Einstellungen positiv auf den Studienerfolg auswirken können.
    Schlagwort(e): Social Science ; Statistics ; Education ; Science ; Physics ; thema EDItEUR::J Society and Social Sciences::JH Sociology and anthropology::JHB Sociology::JHBC Social research and statistics ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Deutsch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 14
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-07
    Beschreibung: This open access book is written by world-recognized experts in the fields of applied superconductivity and superconducting accelerator magnet technologies. It provides a contemporary review and assessment of the experience in research and development of high-field accelerator dipole magnets based on Nb3Sn superconductor over the past five decades. The reader attains clear insight into the development and the main properties of Nb3Sn composite superconducting wires and Rutherford cables, and details of accelerator dipole designs, technologies and performance. Special attention is given to innovative features of the developed Nb3Sn magnets. The book concludes with a discussion of accelerator magnet needs for future circular colliders. ; Broadens our understanding of design and performance limits of high-field Nb3Sn accelerator magnets for a future very high energy hadron collider Offers beginners a concise overview of the relevant design concepts for a new generation of superconducting accelerator magnets based on Nb3Sn superconductor Illustrates the complete process of accelerator magnet design and fabrication Provides a contemporary review and assessment of the past experience with Nb3Sn high-field dipole accelerator magnets Identifies the main open R&D issues for Nb3Sn high-field dipole magnets
    Schlagwort(e): Physics ; Particle acceleration ; Physical measurements ; Measurement    ; Machinery ; Atoms ; Physics ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDD Scientific standards, measurement etc ; thema EDItEUR::P Mathematics and Science::PH Physics::PHM Atomic and molecular physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHP Particle and high-energy physics ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGB Mechanical engineering::TGBN Engines and power transmission
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 15
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-08
    Beschreibung: This open access book chronicles the rise of a new scientific paradigm offering novel insights into the age-old enigmas of existence. Over 300 years ago, the human mind discovered the machine code of reality: mathematics. By utilizing abstract thought systems, humans began to decode the workings of the cosmos. From this understanding, the current scientific paradigm emerged, ultimately discovering the gift of technology. Today, however, our island of knowledge is surrounded by ever longer shores of ignorance. Science appears to have hit a dead end when confronted with the nature of reality and consciousness. In this fascinating and accessible volume, James Glattfelder explores a radical paradigm shift uncovering the ontology of reality. It is found to be information-theoretic and participatory, yielding a computational and programmable universe.
    Schlagwort(e): Popular works ; Physics ; Epistemology ; Physics ; Statistical physics ; Dynamical systems ; Philosophy and science ; Philosophy ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDT Topics in philosophy::QDTK Philosophy: epistemology and theory of knowledge ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDX Popular philosophy ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDA Philosophy of science ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDZ Popular science ; thema EDItEUR::P Mathematics and Science::PH Physics::PHS Statistical physics ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDT Topics in philosophy::QDTK Philosophy: epistemology and theory of knowledge ; thema EDItEUR::Q Philosophy and Religion::QD Philosophy::QDX Popular philosophy ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDA Philosophy of science ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDX History of science ; thema EDItEUR::P Mathematics and Science::PD Science: general issues::PDZ Popular science ; thema EDItEUR::P Mathematics and Science::PH Physics::PHS Statistical physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 16
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-05
    Beschreibung: An Introduction to the Standard Model of Particle Physics familiarizes readers with what is considered tested and accepted and in so doing, gives them a grounding in particle physics in general. Whenever possible, Dr. Mann takes an historical approach showing how the model is linked to the physics that most of us have learned in less challenging ar
    Schlagwort(e): Nuclear physics ; Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 17
    Publikationsdatum: 2024-03-30
    Beschreibung: This book summarizes results of longstanding research and scientific contributions from many projects and relevant working groups. It collects and evaluates wind and wave climate projections under changing climate having design needs and marine safety in focus. Potential impact of projected climate change in met-ocean conditions on ships and offshore structures is discussed and illustrated by an example of the expected wave climate change on tanker design.
    Schlagwort(e): GE1-350 ; TA1-2040 ; TK1-9971 ; TP248.13-248.65 ; TL1-4050 ; HG1-9999 ; QE1-996.5 ; RS1-441 ; TA401-492 ; Statistics for Engineering ; Computer Science ; Climate Change Management and Policy ; Chemistry and Earth Sciences ; Reliability ; Safety and Risk ; Physics ; Quality Control ; thema EDItEUR::K Economics, Finance, Business and Management::KC Economics::KCV Economics of specific sectors::KCVG Environmental economics
    Sprache: Englisch
    Format: application/octet-stream
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 18
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-04
    Beschreibung: This open access textbook takes the reader step-by-step through the concepts of mechanics in a clear and detailed manner. Mechanics is considered to be the core of physics, where a deep understanding of the concepts is essential in understanding all branches of physics. Many proofs and examples are included to help the reader grasp the fundamentals fully, paving the way to deal with more advanced topics. After solving all of the examples, the reader will have gained a solid foundation in mechanics and the skills to apply the concepts in a variety of situations. The book is useful for undergraduate students majoring in physics and other science and engineering disciplines. It can also be used as a reference for more advanced levels.
    Schlagwort(e): Physics ; Mechanics ; Mechanical engineering ; Elementary particles (Physics) ; Quantum field theory ; bic Book Industry Communication::P Mathematics & science::PH Physics::PHD Classical mechanics ; bic Book Industry Communication::P Mathematics & science::PH Physics::PHQ Quantum physics (quantum mechanics & quantum field theory) ; bic Book Industry Communication::T Technology, engineering, agriculture::TG Mechanical engineering & materials::TGB Mechanical engineering ; thema EDItEUR::P Mathematics and Science::PH Physics::PHD Classical mechanics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGB Mechanical engineering
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 19
    facet.materialart.
    Unbekannt
    Logos Verlag Berlin | Logos Verlag Berlin
    Publikationsdatum: 2024-04-04
    Beschreibung: Die Teilchenphysik als Teilgebiet der modernen Physik gewinnt zunehmend an Bedeutung im schulischen Physikunterricht. In dieser Arbeit wird erstmalig das von Lehrkräften benötigte Fachwissen zur Teilchenphysik modelliert, wobei Fachwissen als ein Teil des Professionswissens verstanden wird. Als Fachwissensdimensionen werden die Inhaltsbereiche und die Wissensarten in den Fokus genommen, für welche jeweils Subfacetten identifiziert und präzise beschrieben werden. Nach einem überblick über die wesentlichen Ideen der Teilchenphysik wird in der Arbeit die sukzessive Modellierung des Fachwissens im Rahmen einer qualitativ und quantitativ angelegten Delphi-Studie vorgestellt. In drei Befragungsrunden wurden zwischen 35 und 65 internationale Expertinnen und Experten aus der teilchenphysikbezogenen Forschung (Fachwissenschaft und Fachdidaktik) und öffentlichkeitsarbeit (u.a. Wissenschaftsjournalismus) sowie erfahrene Lehrkräfte zu den für das Fachwissen relevanten Themen der Teilchenphysik befragt. Empirische Analysen der Befragungsrunden ergaben, dass sich die Dimension Inhaltsbereiche im deklarativen Wissen aus zehn teilchenphysikalischen Themen (z.B. Teilchen in der Hochenergiephysik, die vier fundamentalen Wechselwirkungen) zusammensetzt, von welchen sechs als besonders relevant eingeschätzt wurden. Im Anschluss an die letzte Befragungsrunde wurde theoriegeleitet eine erste Modellierung der Inhaltsbereiche für die Wissensarten des prozeduralen und konditionalen Wissens vorgenommen.
    Schlagwort(e): Science ; Education ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 20
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-04
    Beschreibung: This open access book, published in the Soft and Biological Matter series, presents an introduction to selected research topics in the broad field of flowing matter, including the dynamics of fluids with a complex internal structure -from nematic fluids to soft glasses- as well as active matter and turbulent phenomena. Flowing matter is a subject at the crossroads between physics, mathematics, chemistry, engineering, biology and earth sciences, and relies on a multidisciplinary approach to describe the emergence of the macroscopic behaviours in a system from the coordinated dynamics of its microscopic constituents. Depending on the microscopic interactions, an assembly of molecules or of mesoscopic particles can flow like a simple Newtonian fluid, deform elastically like a solid or behave in a complex manner. When the internal constituents are active, as for biological entities, one generally observes complex large-scale collective motions. Phenomenology is further complicated by the invariable tendency of fluids to display chaos at the large scales or when stirred strongly enough. This volume presents several research topics that address these phenomena encompassing the traditional micro-, meso-, and macro-scales descriptions, and contributes to our understanding of the fundamentals of flowing matter. This book is the legacy of the COST Action MP1305 “Flowing Matter”.
    Schlagwort(e): Physics ; Amorphous substances ; Complex fluids ; Fluids ; Fluid mechanics ; Chemical engineering ; thema EDItEUR::P Mathematics and Science::PH Physics::PHD Classical mechanics::PHDF Physics: Fluid mechanics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHF Materials / States of matter ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science::TGMF Engineering: Mechanics of fluids ; thema EDItEUR::P Mathematics and Science::PH Physics::PHD Classical mechanics::PHDF Physics: Fluid mechanics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHF Materials / States of matter ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TD Industrial chemistry and manufacturing technologies::TDC Industrial chemistry and chemical engineering ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TG Mechanical engineering and materials::TGM Materials science::TGMF Engineering: Mechanics of fluids
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 21
    Publikationsdatum: 2024-04-04
    Beschreibung: Ein zentrales Ziel der fachdidaktischen Forschung stellt die Verbesserung schulischen Unterrichts dar. Eine Transferstrategie zur flächendeckenden Verbreitung wissenschaftlicher Erkenntnisse bildet die Bereitstellung evidenzbasierter, innovativer materialgestützter Unterrichtskonzeptionen. Allerdings fällt das Materialnutzungsverhalten von Lehrkräften individuell sehr unterschiedlich aus, wobei das Zusammenspiel verschiedener Einflussfaktoren auf die Materialnutzung bislang wenig erforscht ist. Ziel der vorliegenden Arbeit ist es daher, dieses Wirkgefüge unter authentischen Bedingungen genauer zu untersuchen. Dazu wurde kriteriengeleitet eine evidenzbasierte, fachdidaktisch innovative Unterrichtskonzeption ausgewählt (das Münchener Unterrichtskonzept zur Quantenmechanik) und den teilnehmenden Lehrkräften fakultativ zur Verfügung gestellt. Mittels eines qualitativen Forschungsansatzes wurden elf Lehrkräfte bei der Implementierung des Konzepts durch ein Interview zu Beginn und am Ende einer Unterrichtsreihe zur Quantenmechanik sowie zwei Unterrichtsbeobachtungen mit je einem anschließenden stimulated recall begleitet. Aus den Ergebnissen folgt, dass die Probanden sich überwiegend heuristisch mit der Konzeption auseinandersetzten und lediglich Elemente auf Sichtstrukturebene implementierten. Das nachgewiesene Wirksamkeitspotential von evidenzbasierten, innovativen Unterrichtskonzeptionen scheint sich folglich lediglich unter bestimmten Bedingungsfaktoren zu entfalten.
    Schlagwort(e): Science ; Education ; Science ; Physics ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::J Society and Social Sciences::JN Education ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Deutsch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 22
    Publikationsdatum: 2022-01-31
    Beschreibung: By creating this comic, Living Science joins the celebrations of the 100th anniversary of the expeditions to the island of Príncipe in São Tomé e Príncipe, and Sobral, in Brazil, which allowed proof of the theory of General Relativity previously predicted by Albert Einstein. This comic will be disseminated and distributed on a large scale and aims to the presentation of the theory of General Relativity, using language understandable throughout the public. In addition, it is intended that the general public be able to value the expeditions made to Island of Príncipe and Sobral by astronomers portrayed here.
    Schlagwort(e): Science communication ; History of science ; Astronomy ; Physics
    Sprache: Portugiesisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 23
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-04
    Beschreibung: Cosmology in Gauge Field Theory and String Theory focuses on the cosmological implications of the gauge theories of particle physics and of string theory. The book first examines the universe's series of phase transitions in which the successive gauge symmetries of the higher-temperature phase were spontaneously broken after the big bang, discussing relics of these phase transitions, more generic relics (baryons, neutrinos, axions), and supersymmetric particles (neutralinos and gravitinos). The author next studies supersymmetric theory, supergravity theory, and the constraints on the underlying field theory of the universe's inflationary era. The book concludes with a discussion of black hole solutions of the supergravity theory that approximates string theory at low energies and the insight that string theory affords into the microscopic origin of the Bekenstein-Hawking entropy. Cosmology in Gauge Field Theory and String Theory provides a modern introduction to these important problems from a particle physicist's perspective. It is intended as an introductory textbook for a first course on the subject at a graduate level.
    Schlagwort(e): Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 24
    Publikationsdatum: 2023-12-20
    Beschreibung: Issues and insights from the fields of brain research, quantum mechanics, and evolutionary theory have passed into novels, and physicists and biologists often use rhetorical metaphors to communicate and even evoke their discoveries. The essays in this volume examine natural scientific themes in literary texts – such as the novels of Richard Powers, Can Hue, and Raoul Schrott – and the use of rhetoric and metaphor in the natural sciences.
    Schlagwort(e): PN1-6790 ; Literature ; Science ; Physics ; bic Book Industry Communication::D Literature & literary studies
    Sprache: Deutsch
    Format: application/octet-stream
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 25
    Publikationsdatum: 2023-12-21
    Beschreibung: In the spring of 2011, a diverse group of scientists gathered at Cornell University to discuss their research into the nature and origin of biological information. This symposium brought together experts in information theory, computer science, numerical simulation, thermodynamics, evolutionary theory, whole organism biology, developmental biology, molecular biology, genetics, physics, biophysics, mathematics, and linguistics. This volume presents new research by those invited to speak at the conference. The contributors to this volume use their wide-ranging expertise in the area of biological information to bring fresh insights into the many explanatory difficulties associated with biological information. These authors raise major challenges to the conventional scientific wisdom, which attempts to explain all biological information exclusively in terms of the standard mutation/selection paradigm. Several clear themes emerged from these research papers: 1) Information is indispensable to our understanding of what life is; 2) Biological information is more than the material structures that embody it; 3) Conventional chemical and evolutionary mechanisms seem insufficient to fully explain the labyrinth of information that is life. By exploring new perspectives on biological information, this volume seeks to expand, encourage, and enrich research into the nature and origin of biological information. Contents: Session One — Information Theory & Biology: Introductory Comments (Robert J Marks II): Biological Information — What is It? (Werner Gitt, Robert Compton and Jorge Fernandez) A General Theory of Information Cost Incurred by Successful Search (William A Dembski, Winston Ewert and Robert J Marks II) Pragmatic Information (John W Oller, Jr) Limits of Chaos and Progress in Evolutionary Dynamics (William F Basener) Tierra: The Character of Adaptation (Winston Ewert, William A Dembski and Robert J Marks II) Multiple Overlapping Genetic Codes Profoundly Reduce the Probability of Beneficial Mutation (George Montañez, Robert J Marks II, Jorge Fernandez and John C Sanford) Entropy, Evolution and Open Systems (Granville Sewell) Information and Thermodynamics in Living Systems (Andy C McIntosh) Session Two — Biological Information and Genetic Theory: Introductory Comments (John C Sanford): Not Junk After All: Non-Protein-Coding DNA Carries Extensive Biological Information (Jonathan Wells) Can Purifying Natural Selection Preserve Biological Information? (Paul Gibson, John R Baumgardner, Wesley H Brewer and John C Sanford) Selection Threshold Severely Constrains Capture of Beneficial Mutations (John C Sanford, John R Baumgardner and Wesley H Brewer) Using Numerical Simulation to Test the “Mutation-Count” Hypothesis (Wesley H Brewer, John R Baumgardner and John C Sanford) Can Synergistic Epistasis Halt Mutation Accumulation? Results from Numerical Simulation (John R Baumgardner, Wesley H Brewer and John C Sanford) Computational Evolution Experiments Reveal a Net Loss of Genetic Information Despite Selection (Chase W Nelson and John C Sanford) Information Loss: Potential for Accelerating Natural Genetic Attenuation of RNA Viruses (Wesley H Brewer, Franzine D Smith and John C Sanford) DNA.EXE: A Sequence Comparison between the Human Genome and Computer Code (Josiah Seaman) Biocybernetics and Biosemiosis (Donald Johnson) Session Three — Theoretical Molecular Biology: Introductory Comments (Michael J Behe): An Ode to the Code: Evidence for Fine-Tuning in the Standard Codon Table (Jed C Macosko and Amanda M Smelser) A New Model of Intracellular Communication Based on Coherent, High-Frequency Vibrations in Biomolecules (L Dent) Getting There First: An Evolutionary Rate Advantage for Adaptive Loss-of-Function Mutations (Michael J Behe) The Membrane Code: A Carrier of Essential Biological Information That is Not Specified by DNA and is Inherited Apart from It (Jonathan Wells) Explaining Metabolic Innovation: Neo-Darwinism Versus Design (Douglas D Axe and Ann K Gauger) Session Four — Biological Information and Self-Organizational Complexity Theory: Introductory Comments (Bruce L Gordon): Evolution Beyond Entailing Law: The Roles of Embodied Information and Self Organization (Stuart Kauffman) Towards a General Biology: Emergence of Life and Information from the Perspective of Complex Systems Dynamics (Bruce H Weber) Readership: Academics, researchers, postgraduates and advanced undergraduates in bioinformatics. Biologists, mathematicians/statisticians, physicists and computer scientists.
    Schlagwort(e): T1-995 ; Molecular Biology ; Mutation/Selection Paradigm ; Numerical Simulation ; Mathematics ; Biophysics ; Physics ; Thermodynamics ; Information Theory ; Evolutionary Theory ; Computer Science ; Linguistics ; Genetics ; Developmental Biology ; Biological Information ; Whole Organism Biology ; bic Book Industry Communication::T Technology, engineering, agriculture::TB Technology: general issues
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 26
    Publikationsdatum: 2022-01-31
    Beschreibung: Physics and literature are two forms of knowing the world that are both complementary and contingent. Poetical-physical ways of writing and metaphors in physical theories are two sides of a coin. Interviews with Ulrike Draesner, Durs Grünbein, Michael Hampe, Jens Harder, Reinhard Jirgl, Thomas Lehr, Ulrich Woelk, and Juli Zeh enrich our knowledge of these two cultures through voices familiar with both sides.
    Schlagwort(e): PN1-6790 ; QC1-999 ; Literature ; Physics ; Interview
    Sprache: Deutsch
    Format: application/octet-stream
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 27
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-04
    Beschreibung: This advanced textbook and reference is the first comprehensive and systematic review of all methods used for the measurement, correction, and control of the beam dynamics of modern particle accelerators. Based on material presented in several lectures at the US Particle Accelerator School, the text is intended for graduate students starting research or work in the field of beam physics. Relativistic beams in linear accelerators and storage rings provide the focus. After a review of linear optics, the text addresses basic and advanced techniques for beam control, plus a variety of methods for the manipulation of particle-beam properties. In each case, specific procedures are illustrated by examples from operational accelerators, e.g., CERN, DESY, SLAC, KEK, LBNL, and FNAL. The book also treats special topics such as injection and extraction methods, beam cooling, spin transport, and polarization. Problems and solutions enhance the book’s usefulness in graduate courses.
    Schlagwort(e): Physics ; Physics ; CERN ; DESY ; Particle accelerator ; Storage ring ; control ; measurement ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 28
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-07
    Beschreibung: This open access book provides a comprehensive toolbox of analysis techniques for ionospheric multi-satellite missions. The immediate need for this volume was motivated by the ongoing ESA Swarm satellite mission, but the tools that are described are general and can be used for any future ionospheric multi-satellite mission with comparable instrumentation. In addition to researching the immediate plasma environment and its coupling to other regions, such a mission aims to study the Earth’s main magnetic field and its anomalies caused by core, mantle, or crustal sources. The parameters for carrying out this kind of work are examined in these chapters. Besides currents, electric fields, and plasma convection, these parameters include ionospheric conductance, Joule heating, neutral gas densities, and neutral winds. ;
    Schlagwort(e): Physics ; Space sciences ; Atmospheric sciences ; Observations, Astronomical ; Astronomy—Observations ; Planetary science ; thema EDItEUR::P Mathematics and Science::PG Astronomy, space and time ; thema EDItEUR::P Mathematics and Science::PG Astronomy, space and time::PGS Solar system: the Sun and planets ; thema EDItEUR::R Earth Sciences, Geography, Environment, Planning::RB Earth sciences ; thema EDItEUR::T Technology, Engineering, Agriculture, Industrial processes::TT Other technologies and applied sciences::TTD Space science::TTDS Astronautics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 29
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2024-04-04
    Beschreibung: This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration.
    Schlagwort(e): Physics ; Physics ; Accelerator Science and Technology ; Beam dynamics ; Beam physics ; Charged particle beams ; Charged particles dynamics ; Free electron laser ; Introduction to Particle Accelerators ; Physics of Particle Accelerators ; Synchrotron radiation ; US Accelerator Physics School ; thema EDItEUR::P Mathematics and Science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 30
    facet.materialart.
    Unbekannt
    Taylor & Francis | CRC Press
    Publikationsdatum: 2024-04-05
    Beschreibung: Volume 1 of this revised and updated edition provides an accessible and practical introduction to the first gauge theory included in the Standard Model of particle physics: quantum electrodynamics (QED).The book includes self-contained presentations of electromagnetism as a gauge theory as well as relativistic quantum mechanics. It provides a uniqu
    Schlagwort(e): Nuclear physics ; Physics ; Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory)
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 31
    Publikationsdatum: 2024-04-05
    Beschreibung: Tensor network is a fundamental mathematical tool with a huge range of applications in physics, such as condensed matter physics, statistic physics, high energy physics, and quantum information sciences. This open access book aims to explain the tensor network contraction approaches in a systematic way, from the basic definitions to the important applications. This book is also useful to those who apply tensor networks in areas beyond physics, such as machine learning and the big-data analysis. Tensor network originates from the numerical renormalization group approach proposed by K. G. Wilson in 1975. Through a rapid development in the last two decades, tensor network has become a powerful numerical tool that can efficiently simulate a wide range of scientific problems, with particular success in quantum many-body physics. Varieties of tensor network algorithms have been proposed for different problems. However, the connections among different algorithms are not well discussed or reviewed. To fill this gap, this book explains the fundamental concepts and basic ideas that connect and/or unify different strategies of the tensor network contraction algorithms. In addition, some of the recent progresses in dealing with tensor decomposition techniques and quantum simulations are also represented in this book to help the readers to better understand tensor network. This open access book is intended for graduated students, but can also be used as a professional book for researchers in the related fields. To understand most of the contents in the book, only basic knowledge of quantum mechanics and linear algebra is required. In order to fully understand some advanced parts, the reader will need to be familiar with notion of condensed matter physics and quantum information, that however are not necessary to understand the main parts of the book. This book is a good source for non-specialists on quantum physics to understand tensor network algorithms and the related mathematics.
    Schlagwort(e): Physics ; Physics ; Quantum physics ; Quantum optics ; Statistical physics ; Machine learning ; Elementary particles (Physics) ; Quantum field theory ; thema EDItEUR::P Mathematics and Science::PH Physics::PHJ Optical physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHS Statistical physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHU Mathematical physics ; thema EDItEUR::U Computing and Information Technology::UY Computer science::UYQ Artificial intelligence::UYQM Machine learning ; thema EDItEUR::P Mathematics and Science::PH Physics::PHJ Optical physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHS Statistical physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHU Mathematical physics ; thema EDItEUR::U Computing and Information Technology::UY Computer science::UYQ Artificial intelligence::UYQM Machine learning
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 32
    facet.materialart.
    Unbekannt
    Coimbra University Press
    Publikationsdatum: 2022-01-31
    Beschreibung: This work brings together various contributions from experts in very diverse areas of knowledge, to discuss the theme ‘Light’ from various points of view. The subjects gathered in this work come from the areas of Physics, Philosophy, Transcendence, Chemistry, Optics, Literature, History of Sciences, History, Geography, International Relations, Biology, Psychology, Art, Cinema and Photography, Medicine and Museology. The texts partially reflect the contents presented at the interdisciplinary colloquium ‘Visões da Luz’ held in October 2015, on the occasion of the International Year of Light 2015, under the aegis of III-UC and open to academia and society, to teachers of the Basic and Secondary Education.
    Schlagwort(e): Geography ; Chemistry ; Literature ; Geology ; Light ; Optics ; Biology ; History ; Physics
    Sprache: Portugiesisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 33
    facet.materialart.
    Unbekannt
    Springer Nature
    Publikationsdatum: 2021-02-10
    Beschreibung: This Open Access biography chronicles the life and achievements of the Norwegian engineer and physicist Rolf Widerøe. Readers who meet him in the pages of this book will wonder why he isn't better known. The first of Widerøe's many pioneering contributions in the field of accelerator physics was the betatron, the second, the linear accelerator, both summarized in a 27 page PhD. The betatron revolutionized the fields of cancer treatment through radiation therapy and also nondestructive testing; hospitals worldwide installed Widerøe's machine and today’s modern radiation treatment equipment is based on his inventions. The most recent renaissance of the linac provides unprecedented x-ray intensities at Free Electron Laser (FEL) facilities in operation and construction worldwide. . Widerøe’s story also includes a fair share of drama, particularly during World War II when both Germans and the Allies vied for his collaboration. Widerøe held leading positions in multinational industry groups and was one of the consultants for building the world's largest nuclear laboratory, CERN, in Switzerland. He gained over 200 patents, received several honorary doctorates and a number of international awards. The author, a professional writer and maker of TV documentaries, has gained access to hitherto restricted archives in several countries, which provided a wealth of new material and insights, in particular in relation to the war years. She tells here a gripping and illuminating story.
    Schlagwort(e): Popular works ; Physics ; Particle acceleration ; Cancer research ; Physics ; bic Book Industry Communication::M Medicine::MJ Clinical & internal medicine::MJC Diseases & disorders::MJCL Oncology ; bic Book Industry Communication::P Mathematics & science::PD Science: general issues::PDX History of science ; bic Book Industry Communication::P Mathematics & science::PD Science: general issues::PDZ Popular science ; bic Book Industry Communication::P Mathematics & science::PH Physics::PHP Particle & high-energy physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 34
    facet.materialart.
    Unbekannt
    IntechOpen | IntechOpen
    Publikationsdatum: 2024-04-04
    Beschreibung: This book describes the recent evolution of solid-state physics, which is primarily dedicated to examining the behavior of solids at the atomic scale. It also presents various state-of-the-art reviews and original contributions related to solid-state sciences. The book consists of four sections, namely, solid-state behavior, metastable materials, spintronics materials, and mechanics of deformable bodies. The authors’ contributions relating to solid-state behavior deal with the performance of solid matters pertaining to quantum mechanics, physical metallurgy, and crystallography. The authors’ contributions relating to metastable materials demonstrate the behavior of amorphous/bulk metallic glasses and some nonequilibrium materials. The authors’ contributions relating to spintronic materials explain the principles and equations underlying the physics, transport, and dynamics of spin in solid-state systems. The authors’ contributions relating to the mechanics of deformable bodies deal with applications of numeric and analytic solutions/models for solid-state structures under deformation. Key Features:Issues in solid-state physics, Lagrangian quantum mechanics,Quantum and thermal behavior of HCP crystals,Thermoelectric properties of semiconductors,Bulk metallic glasses and metastable atomic density determination,Applications of spintronics and Heusler alloys, 2D elastostatic, mathematical modeling and dynamic stiffness methods on deformable bodies.
    Schlagwort(e): Physics ; bic Book Industry Communication::P Mathematics & science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 35
    facet.materialart.
    Unbekannt
    Taylor & Francis | Routledge
    Publikationsdatum: 2024-04-05
    Beschreibung: Introduction to Gauge Field Theory provides comprehensive coverage of modern relativistic quantum field theory, emphasizing the details of actual calculations rather than the phenomenology of the applications. Forming a foundation in the subject, the book assumes knowledge of relativistic quantum mechanics, but not of quantum field theory. The book
    Schlagwort(e): Nuclear physics ; Physics ; Quantum physics (quantum mechanics and quantum field theory) ; thema EDItEUR::P Mathematics and Science::PH Physics::PHN Nuclear physics ; thema EDItEUR::P Mathematics and Science::PH Physics ; thema EDItEUR::P Mathematics and Science::PH Physics::PHQ Quantum physics (quantum mechanics and quantum field theory)
    Sprache: Englisch
    Format: image/jpeg
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 36
    facet.materialart.
    Unbekannt
    Frontiers Media SA
    Publikationsdatum: 2024-04-04
    Beschreibung: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact
    Schlagwort(e): Fractional Differential Equations ; Real-World Applications ; Physics ; fractional calculus ; computational techniques ; Fractional order models ; thema EDItEUR::P Mathematics and Science::PD Science: general issues ; thema EDItEUR::P Mathematics and Science::PH Physics
    Sprache: Englisch
    Format: image/jpeg
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 37
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 38
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 15-25 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A molecular theory of protein secondary structure is presented that takes account of both local interactions inside each chain region and long-range interactions between different regions, incorporating all these interactions in a single Ising-like model. Local interactions are evaluated from the stereochemical theory describing the relative stabilities of α- and β-structures for different residues in synthetic polypeptides, while long-range effects are approximated by the interaction of each chain region with the averaged hydrophobic template. Based on this theory, an algorithm of protein secondary structure prediction is proposed and examples are given of “blind” predictions made before the x-ray structural data became available.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 39
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 27-31 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: To increase our understanding of peptide-water interactions, we are simulating the behavior of water molecules in the intermolecular channels of [Phe4Val6]antamanide dododecahydrate crystals. There is good overall agreement between the positions predicted using two alternative potential functions and those that have been observed by x-ray diffraction. Detailed differences between the predictions for the two potential functions are discussed.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 40
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 49-58 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Experimental measurements of disulfide bond stability at various stages of protein folding are considered in terms of the effective concentrations of the thiol groups relative to each other; values of up to 107M are observed, so that intramolecular interactions within the interior of a protein are much more stable, and provide greater stability to the folded conformation, than those on the surface or in a flexible segment. Intramolecular interactions can have substantially lower free energies than intermolecular, for solely entropic reasons; this implies that polar interactions, such as hydrogen bonds and salt bridges, can provide net stabilization to a folded conformation, in spite of the unfolded protein having intermolecular interactions with the solvent. These considerations can account for the lower free energy and enthalpy of the folded state and are useful for considering protein flexibility.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 41
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 87-91 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Near- and far-uv CD spectra of microtubule protein preparations have been examined to study the possible role of protein conformation in relation to the kinetics of the self-assembly of these proteins into microtubules in vitro. Although tubulin can form conformations with high helical content under apolar solution conditions, this transformation is apparently not involved in self-assembly. There is no major perturbation of tubulin near-uv CD by reagents and solution conditions favoring assembly. Thus, in these preparations, tubulin, as dimer and as oligomer with MAPs, is effectively in the conformation in which it undergoes self-assembly. This conclusion is consistent with a hybrid model of assembly of microtubule protein involving direct incorporation of oligomeric species as an alternative to the condensation polymerization of tubulin dimer as the exclusive assembly mechanism.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 42
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 101-105 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The ligand-modulated kinetics of the autoproteolysis of thermolysin and the high-molecular-weight products of the reaction provide evidence for the conclusion that separation of the two structural domains is most probably the first step on the unfolding pathway of the protein under native conditions.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 43
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 125-129 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The in vivo pathway of folding and subunit assembly of a trimeric bacteriophage protein has been studied by characterizing precursors to the native protein and by analyzing temperature-sensitive mutations that kinetically block the pathway. The native trimer is formed via an intermediate composed of three partially folded chains, the protrimer. At 39°C, temperature-sensitive mutations prevent the formation of both the native trimer and the protrimer, possibly by destabilizing earlier intermediates. However, the mutations do not affect the stability of the native protein, formed at 30°C. Thus, these mutations identify amino acid residues involved in interactions that determine the folding pathway.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 44
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 1677-1696 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: We studied the kinetics of O2 release by oxyhemoglobin caused by sodium dithionite, in the presence and in the absence of organic cosolvents (monohydric alcohols and formamide) at 10°C. This study was performed by using standard stopped-flow techniques coupled with microprocessor-based data acquisition. We have fitted the experimental data to a mathematical expression obtained on the basis of a two-state model that takes into account the kinetic heterogeneity between α- and β-chains and the presence of αβ-dimers in oxyhemoglobin solutions. Results indicate that the cosolvents mainly affect the allosteric parameter L, i.e., the T ⇄ R conformational equilibrium of hemoglobin, leaving the intrinsic deoxygenation rates of both R and T states almost unaltered. The L values obtained in the present work are in excellent agreement with analogous values previously estimated from oxygen equilibrium measurements.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 45
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 1657-1675 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Porcine submaxillary mucin (PSM) is a glycoprotein composed of a protein core and frequent, short oligosaccharide side chains. We report static and dynamic light scattering experiments and intrinsic viscosities for PSM in aqueous solvent systems. In 0.1M NaCl solution, the data suggest PSM exists as large, internally branched, highly hydrated, polydisperse aggregates that slowly dissociate to give a stable species of weight-average molecular weight (Mw) 7.4 × 106. In 6M GdnHCl solution, the noncovalent bonds between PSM molecules are broken, giving a highly elongated molecule of Mw = 2.0 × 106. The irreversible nature of this dissociation suggests that the forces that stabilize the native aggregates of PSM in 0.1M NaCl are specific in nature. On reduction of PSM with mercaptoethanol, the polydispersity decreases and Mw also decreases to 9 × 105. A discrete change is observed in the solution properties of PSM in 0.1M NaCl at a concentration of 2mg/mL, manifested by a sudden decrease in the translational diffusion coefficient, an increase in viscosity number, and a decrease in slope of the osmotic compressibility. We tentatively propose that a weak and reversible secondary association process occurs at this concentration, although a purely hydrodynamic interaction cannot be ruled out.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 46
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The uv linear dichroism of calf thylus DNA has been studied at different degrees of orientation both in flow-oriented ethanol-water solutions and in a stretched aqueous host of poly(vinyl alcohol) (PVA). The reduced dichroism (LDR) curves in the region 250-290 nm for DNA in PVA films at 75 and 100% relative humidity (r.h.) are in fair agreement with the curves calculated for the A- and B-forms of DNA, based on the fiber structures and the π-π* transitions of the free bases. This suggests that DNA adopts its A and B conformations in PVA at 75 and 100% r.h. In ethanol, on the other hand, a deviation from the A-form spectrum shows that the conformation of DNA in the solution can differ from the fiber structure. At shorter wavelenghts, a positive contribution to LDR is explained in terms of an out-of-plane polarized n-π* transition.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 47
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 1759-1767 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A vibrational analysis has been performed for a double-helix-single-strand junction. A Green's function technique has been used in treating the junction as a defect on an otherwise perfect system of infinite chain homopolymers. We calculate that the hydrogen-bond stretching at the junction is amplified by a factor of two relative to the interior of the double helix, B poly(dG)-poly(dC). Breathing modes localized near the junction have also been predicted at 77 and 94 wave numbers. The calculated results are shown to be consistent with predictions from recent nmr studies.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 48
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 49
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Nmr studies of the protected and free tetrapeptide Gly-Pro-Gly-Gly were carried out in β-turn-supporting solvents, that is, in CDCl3 for Z-Gly-Pro-Gly-Gly-OMe and in Me2SO-d6 for H-Gly-Pro-Gly-Gly-OH. Comparisons with specifically α-deuterated analogs gave complete assignments of the NH and methylene regions. Analysis of chemical shifts, coupling constants, and the temperature dependence of chemical shifts show that the peptide adopts a type II β-turn conformation. This turn is stabilized for the protected tetrapeptide by two hydrogen bonds between (i) C=O (Gly1) and NH(Gly4), and (ii) urethane function NH and methyl ester C=O.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 50
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Ab initio minimal and split-valence basis set calculations have been performed on compounds that are involved in retro-inverso modifications, i.e., gem-diaminoalkyl and malonyl structures. These calculations are compared with empirical force field calculations and the minor differences discussed. All calculations agree that the preferred helical conformation of the isolated gem-diaminoalkyl and malonyl derivatives of residues found in the retro-inverso modified peptides is 5-8 kcal/mol lower than the Ceq7 conformation preferred by the isolated peptide residues. Population analysis and contour plots of the charge distribution are used to help explain the differences between the model compounds.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 51
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 52
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 53
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 1449-1460 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: SCF-LCAO-MO ab initio calculations were carried out for the interaction between a charged amino acid and a water molecule. The results obtained were fitted by an analytical potential function of the atom-atom type, and the corresponding potential surfaces were examined by means of orientationally optimized isoenergy contour maps. Monte Carlo simulations were also carried out on a few selected solute-water clusters at T = 300 K, in order to obtain insight into the solvation structure.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 54
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An improved cube method has been developed for calculating the intensity of diffuse x-ray scattering of macromolecules in solution using a certain set of their atomic coordinates. The technique is based on the ideas of B. Lee and F. M. Richards [(1971) J. Mol. Biol. 55, 374-400] and Richards [(1977) Annu. Rev. Biophys. Bioeng. 6, 151-176] on the possibility of estimating the molecular and accessible surface of a particle by “rolling” a sphere, simulating a water molecule, on its molecular surface. It is shown that this technique is more advantageous than earlier versions of the cube methods. The improved technique for calculating scattering curves was utilized for several globular proteins, and for the first time, reliable scattering curves were obtained for protein-“bound” water complexes. In the case of globular proteins and tRNA, this technique has permitted a strict evaluation of their accessible surfaces, their volumes, and, apparently for the first time, their complete molecular surfaces.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 55
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 56
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The DNA-ligand interactions of a series of phenanthridinium compounds with various combinations of amino, azido, and hydrogen functions at R3 and R8 were examined to determine the contribution of these particular substituents to ligand binding. Spectrophometric titrations using calf-thymus DNA emphasized the importance of amino substituents in conferring a strong interaction and also stabilizing the interaction against reversal by high ionic strength. Although azido groups were not as effective as amino groups, they were more effective than hydrogen functions in enhancing the interaction. Furthermore, an amino substitution at R8 was consistently, though only slightly, more effective than an amino substituent at R3. The results from superhelical titrations using plasmid pBR322 DNA demonstrated that analogs with amino and/or azido functions at both R3 and R8 produced the greatest unwinding, and compounds with an amino or an azido function at R8 proved more effective than those with the corresponding amino or azido substituent at R3.
    Zusätzliches Material: 14 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 57
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The magnetic shielding constant of the 31P nucleus of the dimethylphosphate anion is calculated by an ab initio method for different values of the torsion angles about the PO ester bond and different orientations of the methyl groups. The results obtained tend to show that both types of conformational parameters contribute to the value of σ31P. The largest shielding is obtained when the methyl groups are staggered with respect to the PO bond; the smallest, for the eclipsed arrangement. Measurements carried out on the 16 deoxyribodinucleoside monophosphates show that in the majority of cases σ31P is shifted toward lower field for the dimers having large values of 3JPH3′ and 3JPH5′(5″). The theoretical results are discussed in relation to experimental data for polynucleotides and nucleic acids.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 58
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 471-491 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The optical modes of DNA that displace one strand against the other are modeled by the motion of an oscillator in an asymmetric quartic double-well potential whose minima represent the A- and B-conformations. Assuming that the variation of the polarizability during vibration derives mainly from the tilting of the base rings relative to the helix axis, the total polarizability tensor is shown to possess approximately ellipsoidal symmetry and to depend nonlinearly on the instantaneous displacement of the two strands. The Raman spectrum of a collection of randomly oriented molecules is calculated. It consists of one or more peaks with characteristic shape. The depolarization ratio is 3/4, independent of molecular conformation and frequency. The results are discussed in the light of existing experimental and theoretical information.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 59
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 511-536 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Using the semiempirical potential functions, conformational energies of the model compounds DMP-, d(pCp), d(pGp), and d(pCpGpCp) are calculated, and the B → Z transition is discussed along the pseudorotational path of the sugar ring. For dimethylmonophosphate anion, DMP-, the energy contour map is presented and the stabilities of the phosphodiester conformations discussed. For the sugar ring without the base attached, the minimum energies for each sugar-puckering form are calculated along the pseudorotational path. The energy barrier of the interconversion between the C(3′)-endo form and the C(2′)-endo form is calculated to be about 2.0 kcal/mol. From the conformational energy calculations of the interconversions of mononucleoside diphosphates, d(pCp) and d(pGp), between the C(2′)-endo conformer and the C(3′)-endo conformer, the purine sugar segment is known to be more convertible than the pyrimidine sugar segment. The results also support the finding that the pseudorotational transition occurred with the O(1′)-endo form more easily than with the O(1′)-exo form. Based on the results of conformational studies of DMP-, d(pCp), and d(pGp), a topological transition of the handedness of the model compound, d(pCpGpCp), is studied. The left-handed Z-form is found to be less stable by about 8.5 kcal/mol than is the right-handed B-form. The energy barrier of the Z → B transition is calculated to be about 17.4 kcal/mol. The contributions of the electrostatic and nonbonded energies to the energy barrier are discussed in connection with the conformation changes of the model compound, d(pCpGpCp).
    Zusätzliches Material: 16 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 60
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 593-599 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The dielectric properties of aqueous solutions of DNA were measured at frequencies ranging from 0.1 to 12 GHz. The results are analyzed using the Maxwell mixture theory and yield a value for the hydration of the DNA of about 0.4 g/g, which is in the range observed in other investigations. No evidence was found for an additional absorption effect at microwave frequencies, which has been predicted to occur in certain DNA analogs due to the vibrational excitation of the double helix by the applied microwave field.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 61
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Self-association of substance P and its C-terminal partial peptide sequences was studied by CD, quasi-electric light scattering, and sedimentation experiments. CD spectra of these peptides are strongly influenced by self-association. They exhibit strong characteristic negative ellipticities, suggesting the formation of a presumably B-type ordered structure. The tendency to form multimers depends on chain length and constitution and has its maximum at the octapeptide (SP 8). The peptide multimers have a broad distribution of sizes in the range of 30- and 800-nm diameter. Subdivision of this distribution into two size classes gives mean diameters of 60-100 nm (predominating)/200-800 nm for substance P and 30-50 nm/200-800 nm for SP 8 multimers.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 62
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 819-829 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 13C-nmr chemical shifts of backbone carbonyl and side-chain β-carbons in polypeptides provide structural information. Recent utilization of substituent effects on 13C-nmr chemical shifts (principally γ-effects) has permitted the rationalization of their sequence and conformation dependence when observed in linear, flexible polypeptides. In this report, we apply the γ-effect method to study the 13C-nmr chemical shifts observed in solution and in the solid state for the backbone carbonyl and side-chain β-carbons in conformationally rigid polypeptides, which are usually cyclic. As found previously for flexible, linear polypetides, the relative 13C-nmr chemical shifts observed for the backbone carbonyl and side-chain β-carbons in conformationally rigid polypeptides are predictable from knowledge of their peptide residue sequence (primary structure) and conformation (secondary structure) via the γ-effect method.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 63
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 847-852 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 64
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The CD spectra of the peptides Boc-X-(Aib-X)n-OMe (n = 1, 2, 3) and Boc-(Aib-X)5-OMe, where X = L-Ala or L-Val have been examined in several solvents. The X = Ala and Val peptides behave similarly in all solvents, suggesting that the Aib residues dominate the folding preferences of these peptides. The decapeptides adopt helical conformations in methanol and trifluoroethanol, with characteristic negative CD bands at 222 and 205 nm. In the heptapeptides, similar spectra with reduced intensities are observed. Comparison with nmr studies suggest that estimates of helical content in oligopeptides by CD methods may lead to erroneous conclusions. The pentapeptides yield solvent-dependent spectra indicative of conformational perturbations. Peptide association in dioxane results in an unusual spectrum with a single negative band at 210 nm for the decapeptides. Disaggregation is induced by the addition of methanol or water to dioxane solutions. Aggregation of the heptapeptides is less pronounced in dioxane, suggesting that a critical helix length may be necessary to promote association stabilized by helix dipole-dipole interactions.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 65
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2501-2506 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 66
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2523-2538 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An extended retro-inverso modification was introduced at the central six residues of the somatostatin molecule, the region of internal enzymatic degradations. The synthesis of the analog [Ala4,g-Phe6-r-D-Phe7-r-D-Trp8-r-D-Lys9-r-D-Thr10-m-R,S-Phe11]-somatostatin required a unique strategy accommodating the unusual structure. Side-chain protection based on the t-butyl group in combination with Fmoc and Nps α-amino protection was employed. The key component containing the gem-diaminoalkyl residue was generated by an iodobenzene bistrifluoroacetate-mediated reaction. The separation of diastereomers of the cyclic tetradecapeptide in highly pure form was accomplished by high-performance liguid chromatography on a semipreparative scale. The analogs exhibited very low potency in the growth hormone inhibition test in vitro. This is interpreted as the consequence of the complex structural changes created by the extended retro-inverso modification.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 67
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 831-841 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The interaction of poly-5-bromouridylic acid [poly(BU)] with adenosine and 9-methyladenine was studied by equilibrium dialysis, optical melting, and microcalorimetry. The stacking free energy, ω, was estimated as -17.6 kJ/mol for adenosine·2poly(BU) and -18.8 kJ/mol for 9-methyladenine·2poly(BU) from the binding isotherms constructed from equilibrium dialysis results. The binding isotherms constructed from a series of melting curves also gave ω values for adenosine·2poly(BU). The thermal stability of the complex depends on monomer concentration, and the partial molar enthalpies of the complex formation at the midpoint of the transition were evaluated from the Tm coefficients as a function of free monomer concentration. The values of -92.0 and -90.4 kJ/mol were obtained for adenosine·2poly(BU) and 9-methyladenine·2poly(BU) in 0.4M NaCl-0.02M Na-cacodylate-5 × 10-4M EDTA (pH 7.0), respectively. Microcalorimetric measurements provided lower integral heats of reaction values for these complexes, i.e., -73.2 kJ/mol for adenosine·2poly(BU) and -71.5 kJ/mol for 9-methyladenine·2poly(BU). A comparison with a polyribouridylic acid system provided a quantitative understanding of a stabilization by bromination in terms of thermodynamic parameters.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 68
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The nature of internal and overall motions in native (double-stranded) and denatured (single-stranded) DNA fragments 120-160 base pairs (bp) long is examined by molecular-dynamics modeling using 13C-nmr spin-relaxation data obtained over the frequency range of 37-125 MHz. The broad range of 13C frequencies is required to differentiate among various models. Relatively narrow linewidths, large nuclear Overhauser enhancements (NOEs), and short T1 values all vary significantly with frequency and indicate the presence of rapid, restricted internal motions on the nanosecond time scale. For double-stranded DNA monomer fragments (147 bp, 24 Å diam at 32°C), the overall motion is that of an axially symmetric cylinder (τx = ∼10-6 s;τZ = ∼1.8 × 10-8s), which is in good agreement with values calculated from hydrodynamic theory (τx = ∼1.8 × 10-6 s; τZ = ∼2.7 × 10-8 s). The DNA internal motion can be modeled as restricted amplitude internal diffusion of individual C—H vectors of deoxyribose methine carbons C1′, C3′, and C4′, either with conic boundary conditions (τw = ∼4 × 10-9 s, θcone = ∼21°) or as a bistable jump (τA = τB = ∼2 × 10-9 s, θ = ∼15°). We discuss the critical role in molecular-dynamics modeling played by the angle (β) that individual C—H vectors make with the long axis of the DNA helix. Heat denaturation brings about increases in both the rate and amplitude of the internal motion (described by the wobble model with τW = ∼0.2 × 10-9 s, θcone = ∼50°), and overall motion is affected by becoming essentially isotropic (τx = τZ = ∼5 × 10-8 s) for the single-stranded molecules. Since 13C-nmr data obtained at various DNA concentrations for C2′ of the deoxyribose ring is not described well by the above models, a new model incorporating an additional internal motion is proposed to take into account the rapid, extensive, and weakly coupled motion of C2′.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 69
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 70
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 191-194 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 71
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 257-270 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A molecular-dynamics simulation was used to carry out an introductory study of the hydration of a section of a rigid single A- or B-DNA helix with one Na+ counterion per nucleotide. Four Na+ ions and four nucleotides and periodic boundary conditions were used to mimic an infinite helix. The atoms of the helix and the Na+ ions were assumed to be Lennard-Jones spheres that also carried charges. Stillinger four-point charge model water molecules were used. We carried out five calculations, for 26 and 46 water molecules in B-DNA and 20, 32, and 46 in A-DNA fragments. The arrangements of the Na+ ions are found to have some similarities to those obtained by Clementi and Corongiu. In the calculations with 46 water molecules, we found that two Na+ ions can be bridged by about two water molecules and form a hydrated bound pair, which in turn forms a bridge between the guanine N7 and a near phosphate group. These bound pairs may be important in stabilizing the helix structure of DNA molecules.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 72
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 313-323 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Ethylurea was used to weaken hydrophobic interactions during collagen fibrillogenesis in vitro. Intact and enzyme-digested type I collagen was studied. In all preparations, ethylurea decreased the extent and rate of fibril formation, inhibition being greatest in the enzyme-digested collagens. With intact collagen (and probably also with carboxypeptidasedigested collagen), there was no evidence the ethylurea altered the mechanism of fibril growth; in pepsin-digested collagen, however, the growth mechanism was altered by ethylurea, possibly reflecting a conformational change of the “hydrophobic cluster” in the C-terminal peptide. Such a structural change could occur in a hydrophobic environment once the distal portion of the C-terminal peptide (presumed to be essential for its structural stability) is removed by pepsin. The results further emphasize the importance of hydrophobic interactions in collagen fibril nucleation and growth in vitro.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 73
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 74
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: We report the crystal-structure analysis of a complex involving the drug proflavine and the two dinucleoside monophosphates cytidylyl-3′,5′-adenosine (CpA) and uridylyl-3′,5′-guanosine (UpG). The planar drug molecule is intercalated between C⃛G and U⃛A Watson-Crick base pairs, in a double-helical fragmentlike arrangement. Sugar conformations at the 3′-ends of the two strands are dissimilar. The backbone conformations fall within the ranges of values noted previously for dinucleoside intercalation complexes, and some correlations involving these are noted. The separation of the two strands and the basic twist angle of 16°, compared to other reported complexes, are indicative of sequence-dependent effects of the drug binding.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 75
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1057-1066 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Helical hydrophobic moment ratios, 〈h2〉/〈H2〉, have been evaluated for 34 polypeptides under conditions where the helix content is dictated solely by the short-range interactions operative in aqueous media. The mean-square helical hydrophobic moment is denoted by 〈h2〉, and 〈H2〉 is the averaged of the squared hydrophobicites. This ratio would be one in absence of any correlation in the hydrophobicities of amino acid residues in helices. The 〈h2〉/〈H2〉 tend to be substantially larger than values of the analogous ratio formulated for the mean-square dipole moments of typical synthetic polymers. For 24 of the 34 polypeptide chains considered, 〈h2〉/〈H2〉 is found to be greater than one, indicating a tendency to form helices with amphiphilic character. The ratio is exceptionally large in the case of the δ-hemolysins. It is also large for two other surface-active peptides, for two of the four apolipoproteins examined, and for myohemerythrin. A much smaller 〈h2〉/〈H2〉 is found for melittins. If melittins is to form helices with large 〈h2〉/〈H2〉, the configurational statistics must be governed by effects in addition to those short-range interactions that occur when water is the solvent.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 76
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 77
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Conformational-energy computations have been carried out for the N-acetyl-N′-methylamides of the Pro-Pro, Pro-Gly, and Gly-Pro dipeptides and of the Pro-Pro-Gly-Pro tetrapeptide, serving as models for the conformational analysis of single-stranded poly(Gly-Pro-Pro). The probability of β-bend formation for the Pro-Gly sequence is very high, viz., 0.72 for the terminally blocked Pro-Gly dipeptide, and rises to 0.86 in the tetrapeptide. The β-bend conformations of the Pro-Gly sequence are of low energy in single-chain poly(Gly-Pro-Pro) as well. The β-bend structure had been postulated earlier to be a requirement for post-translational proline hydroxylation during the biosynthesis of collagen. The present results lend strong support to this proposal by demonstrating that the β-bend structure is energetically favorable and hence can be accommodated easily in single-stranded poly(Gly-Pro-Pro).
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 78
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1241-1248 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The interaction of Cu(II) with the protamine scylliorhinine Z3 was studied by means of CD measurements. At a 1:1 molar ratio, three complexes are formed. (1) In the pH range 5-6.5, the results suggest the formation of a five-membered chelate ring through the coordination of two nitrogen atoms, the N-terminal and the contiguous peptide nitrogen. (2) At pH ≥ 6.4, there is involvement of the lateral NH2 group of Arg; at pH 6.5-8, the formation of a 3N cupric complex is strongly suggested. (3) At pH ≥ 8, results indicate the formation of a 4N complex as a major species in Cu(II)-Z3 solution. The transformation from a 2N to a 3N complex, and from a 3N to a 4N complex was followed with the help of the σ(αNH2) → Cu(II) charge-transfer dichroic band transitions. At Cu(II):Z3 molar ratios ≥ 2 and at pH 〉 8, a new dichroic band appears, indicating the involvement of the tyrosine residue side chain in metal-ion complexation.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 79
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Studies of the optical birefringence of solutions of acid-soluble collagen from rat-tail tendon at 22°C in the pH range 1.0-6.0 show that collagen exhibits an isotropic to mesophase transition only between pH 2.4 and 3.0 at 10% weight concentration. Such liquid crystalline order is probably essential for the orientation of collagen in a magnetic field. When solutions of neutral salt-soluble collagen were precipitated at pH 7.0 by warming to 37°C (“heat gelling”) in a magnetic field of ca. 20 kG, the resulting fibrils wee oriented perpendicular to the direction of the field. Heat gelling is shown to be a useful technique for maintaining the orientation induced in precursor solutions even after the sample is removed from the magnetic field.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 80
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1295-1306 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Polyamines are ubiquitous cellular components that interacts strongly with nucleic acids. Although many of the interactions of oligocations with DNA can be rationalized with polyelectrolyte theories that treat counterions as point charges, some structural effects are evident. We have explored the effects of polyamine structure on one important aspect of DNA behavior, its thermal melting transition, by using a series of spermidine analogs NH3(CH2)3NH2(CH2)nNH33+, where n varies from 2 to 8 [Jorstad et al. (1980) J. Bacteriol. 141, 456-463]. For spermidine itself, n = 4. Tm for calf-thymus DNA in the presence of each of these analogs, and the other naturally occurring polyamines putrescine2+ and spermine4+, was measured over a wide range of NaCl concentrations and polyamine:DNA phosphate ratios. There are modest, but significant structural effects. particularly with the shorter n = 2 and 3 derivatives, whose geometry my not allow full electrostatic interaction with DNA. Longer analogs, on the other hand, are not much different than spermidine in their effects on Tm, though a moderate maximum occurs at n = 5. Since polyamines are important in the cellular condensation and packaging of DNA, we have also delineated the critical polyamine and salt concentrations that are required to cause DNA aggregation. Here again, there are significant structural effects, which are not easily rationalized by any simple considerations.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 81
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1315-1323 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The observed difference between the CD spectrum of B-DNA mononucleosomes and that of free DNA has been attributed to the tertiary structure of the core DNA. This conjecture is tested here. The tertiary structure is modeled as an optical system consisting of two identical, planar, linear retarders rotated with respect to each other. The retarders have the same linear birefringence and linear dichroism as oriented B-DNA. Such an optical system is circularly dichroic. The predicted wavelength dependence and magnitude of the CD are in reasonably close agreement with the experimental results.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 82
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1367-1377 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The absorption and CD spectra of the complexes of poly(L-arginine) (PLA) and azo dyes have been measured in aqueous solution. On complexation, Blue-shifted additional absorption bands were observed. In the wide pH 4-11 range, induced CD was observed at the visible wavelengths corresponding to the blue-shifted absorption bands. The induced CD arose from the dimeric dye molecules bound to PLA in the α-helical structure. When a modified analysis of induced CE is made by the excition chirality method, the origin of the induced CD can be assigned to the dipole coupling. The PLA-dye complexes showed the counterlockwise (negative, S) chirality of the transition dipole moments of dyes.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 83
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1347-1365 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Ionization properties of the tyrosyl groups of bovine plasma albumin in various conformational states - the native state (N), the two acid states (F and E), and the state (B) stable at slightly alkaline pH - were studied by means of a stopped-flow-pH-jump technique. The technique allows us to obtain the tyrosyl titration curve in a conformational state that is unstable in the pH region of the titration. The pH jumps from the N and B states to various alkaline pH's, where the tyrosines ionize to bring about a time-dependent increase in absorption at 296 nm, indicating that a number of the tyrosines buried initially become susceptible to ionization as a result of the alkaline transition occurring above pH 10.8. Extrapolation of the observed absorption change to zero time gives a spectrophotometric titration curve in the initial conformational state. Only 30-401% of the 19 tyrosines of the protein can ionize both in the N and the B state at pH 12. The pH jumps from the F and E states, on the other hand, give a decrease in absorption between pH 9 and 11.7, indicating that the tyrosyl groups initially exposed are remarked by refolding after the pH jumps, and the zero-time titration curves show that essentially all the tyrosyl groups ionize normally in these acid states. The results are discussed in relation to the known results of the tyrosyl exposure of the protein measured by other techniques, and the consistency among them demonstrates the effectiveness of the pH-jump titration method. Hydrogen bonding between the abnormal tyrosyl and carboxylate groups as a mechanism to stabilize native albumin is suggested from characteristics of the alkaline transition, which also involves the exposure of the tyrosyl groups, and from the tyrosyl titration curves in the native and acid states.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 84
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1137-1139 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 85
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Two series of peptides with hydrophobic side chains, Nps-(L-Leu-L-Leu-L-Ala)n-OEt and Nps-(L-Met-L-Met-LLeu)n-OEt (n = 1-6), were synthesized by the fragment condensation method using dicyclohexylcarbodiimide in the presence of N-hydroxysuccinimide. The tripeptide fragments were prepared stepwise by dicyclohexylcarbodiimide-mediated reaction of Nps-amino acids, which were synthesized by an improved rapid procedure.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 86
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1457-1463 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The dielectric properties of sonicated calf-thymus DNA sodium salt in aqueous solutions have been studied in the frequency range from 40 MHz to 2 GHz by time domain spectroscopy (TDS). A dielectric dispersion not previously reported was found, which has a characteristic frequency of about 150 MHz. All of the dielectric parameters are insensitive to the size of DNA fragments and to helix-to-coil transitions. The study of this dispersion as a function of DNA concentration and temperature allows us to conclude that it may be due to counterion fluctuation on short sections, probably in a direction transverse to the macromolecular axis.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 87
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1465-1479 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The oxidation of L-adrenaline (epinephrine) in the presence of [Fe(tetpy)(OH)2]+ ions bound to poly(L-glutamate) or to poly(D-glutamate) has been studied at pH 7 (tetpy = 2,2′:6′,2″:6″,2‴-tetrapyridyl). Electron transfer from the substrate to the central metal ion, which is rate-determining, proceeds stereoselectively only when extensive and possibly specific interactions between adrenaline and the peptidic residues of the ordered polymer in the close environment of the active sites occur. This ensures different steric constraints for the two diastereomeric precursor complexes, which are thought to affect the separation and orientation of the redox centers differently, leading to the observed phenomena. Some data on the catalytic oxidation of L-dopa(3,4-dihydroxyphenylalanine) are also presented, showing stereoselective effects similar to those observed with L-adrenaline, despite the diverse distance of the chiral center from the reacting OH groups. A mechanistic interpretation of the results is discussed in the light of a few general considerations concerning the structural features of the catalytic systems. Possible explanations for the finding that stereoselectivity occurs at the expense of the efficiency of catalysis are also considered.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 88
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The interaction of methyl orange with poly(L-lysine) was studied kinetically by the stopped-flow technique with CD detection, as well as by static CD titration experiments. In the static experiments, the differences observed in the polymer-to-dye ratio dependences of the CD spectra and absorption spectra suggested at least two kinds of bound states of the methyl orange attached to the polymer. The kinetic experiments using the stopped-flow apparatus, however, revealed four distinct reaction processes. The reaction mechanism was elucidated from the concentration dependence of the time constant for each process as follows: the first process was attributed to the bimolecular binding step of methyl orange to the side chain of poly(L-lysine), the second and third process were ascribed to the intramolecular reaction of the polymer-dye complex, and the fourth process was found to be the intermolecular aggregation of the polymer-dye complex. The origin of the stacking of methyl orange on poly(L-lysine) is discussed on the basis of the characteristics of signal amplitudes obtained from the kinetic experiments for these processes.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 89
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Novel devices for the spectroscopic and chromatographic analysis of the denaturation curves of the protein are described. A multidimensional spectroscopic measuring system makes it possible to carry out simultaneous and continuous acquisition of a set of data of different spectroscopic dimensions at several wavelengths in the course of increasing or decreasing denaturational perturbation. GuHCl-gradient chromatography can provide information about the progressive change of the protein volume in the course of increasing GuHCl concentration. Thus, denaturation curves with a high data-point density can be obtained. The data-storing function by a magnetic disk memory provides enough precision for a rigorous investigation of the correlation among the curves that probe different aspects of denaturation. The GuHCl denaturation of RNase A, cytochrome c, and pepsinogen are studied to demonstrate the high performance of these devices. Three types of transitions are found in these three proteins and the multiphasic nature of the transitions is clearly detected in the last two proteins.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 90
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 91
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2169-2172 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 92
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2207-2217 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A sufficiently long semiflexible filamentous macromolecule is theroretically expected to exhibit three different domains of behavior of its apparent diffusion coefficient Dapp(K) as a function of scattering vector K: (1) the small wave vector limit, where Dapp(K) = D0 is the translational diffusion coefficient of the center-of-mass; (2) the universal K3 region, where Dapp(K) = (kBT/6πη)K is a universal function of K independent of any property of the molecule itself; (c) the plateau region at large K2, where Dapp(K) approaches either a plateau, or gradually sloping quasiplateau, characteristic of local (elastic) rigid-body motions of the filament. The existence of each of these different domains has now been established experimentally for at least some polymers. The boundaries of the universal K3 region and the plateau region are determined theoretically here using precise quantitative criteria for universal or plateau behavior of Dapp(K) for a Rouse-Zimm model containing N + 1 subchains with rms subchain extension b. Allowing a maximum of 13% nonuniversal behavior, the domain of the universal K3 region is given by K2R2G = K2Nb2/6 ≥ 7 and K2b2 ≤ 0.54. Allowing as much as 10% nonplateau behavior, the boundary for onset of plateau behavior is K2b2 = 18.3. Dapp(K) is at least 50% nonuniversal when K2b2/6 = 6 ln 3. Extension of these results to DNA is examined theoretically, and good agreement of the pertinent predictions with published experimental data is demonstrated.It is concluded that no truly universal K3 region exists for DNA with Mr ≤ 107 and persistence length a ≥ 450 Å, although marginally (≤17% nonuniversal) universal behavior, is exhibited in a very narrow domain 0.64 × 1010 ≤ K2 ≤ 0.84 × 1010 cm-2 for φ29 DNA (Mr = 11.5 × 106). More than 50% of Dapp(K) is governed by local (elastic) rigid-body motions when K2 = 5.23 × 1010 cm-2. The existence of a very wide region of nonuniversal apparent K3 behavior extending up to very large K2, far into the plateau region, is demonstrated in a plot of Dapp(K)/K vs K2 for the Rouse-Zimm model. This is shown to stem in part from visual artifacts of plotting Dapp(K)/K vs K2, even for rigid species.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 93
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 94
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2353-2366 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The rotational relaxation tiem τ3 of DNA molecules (Mw ≃ 5 × 106) in solution has been determined by the transient electric birefringence method. The analysis of the birefringence decay makes it possible to study only the higher-molecular-weight fraction, the molecules being considered as rigid elongated particles in a short time scale. A marked concentration dependence of the relaxation time has been observed for DNA in low ionic strengths. Above a critical concentration c*, τ3 increases with the DNA concentration, c. The value of c* increases with the ionic strength. For 10-3 ionic strength (with NaCl), c* is about 10 μg/mL; then we observe the same strong concentration dependence of rotational relaxation times as recently reported for rodlike M-13 viruses [Maguire, J. F., McTague, J. P. & Rondelez, F. (1980) Phys. Rev. Lett. 45, 1891-1894]. These results may be discussed in terms of the Doi-Edwards theory for rotational relaxation time of rigid macromolecules [Doi, M. (1975) J. Phys. 36, 607-611; Doi, M. & Edwards, S. F. (1978) J. Chem. Soc. Faraday Trans. 74, 918-932] and the critical concentration above which the interactions between the molecules begin to appear allows determining the corresponding molecular length. We observe a very good agreement between the DNA lengths obtained from the c* values and by using the infinite dilution value of τ3 and Broersma's equation. Therefore, only highly diluted solutions can be used if intrinsic molecular properties based on the rotational diffusion of high-molecular-weight elongated molecules are studied.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 95
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2411-2421 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A thermodynamic treatment of the helix-coil transition of synthetic polypeptides in binary organic solvent mixtures is extended to describe isobaric heat-capacity increments associated with the phenomenon. This development resolves such increments into three components: two associated respectively with intrinsic differences between the ordered and disordered states of the macromolecule and between the coil-solvent complex and its components, and a third term derived from the temperature dependence in the fraction of coil residues bound to active solvent. Insights derived from this analysis are also applied to the discussion of some heat capacity increments associated with the denaturation of globular proteins.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 96
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983) 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 97
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2507-2511 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 98
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 22 (1983), S. 2539-2547 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The temperature dependence of the humidity-sensitive spacing, d, related to the lateral packing of collagen molecules was measured for fully hydrated collagen. In the vicinity of 0°C, a sudden change in d was observed, which was reversible with temperature. In the diffraction profile, below 0°C, a set of diffraction peaks identified with the hexagonal crystalline form of ice was observed. With the reduction in water content, the intensity of the set of diffraction peaks decreased and was found to be zero at a water content of 0.38 g/g collagen. These results were considered to be caused by the frozen water in collagen fibril below 0°C. According to the water content dependence of d, it was considered that up to a certain water content water absorbed would be stowed in the intermolecular space of collagen and above that water content water molecules would aggregate to make pools, i. e., extrafibrillar spaces. The unfreezable bound water was considered to be located in the intermolecular space of collagen. Size of the extrafibrillar space, determined from the intensity analysis of a smallangle x-ray scattering pattern, corroborates the speculation that the water showed in the extrafibrillar space is freezable and free. The formation of the hexagonal crystalline form of ice in the extrafibrillar space was considered to cause the sudden change in d at 0°C.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 99
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1917-1930 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Solution-phase Raman spectra of diastereomeric alanyl dipeptides, D-Ala-L-Ala and L-Ala-L-Ala, and various mono- and dideuterated isotopomers in H2O and D2O, are reported. Spectral differences between the diastereomeric forms are interpreted, using the Raman analog of the coupled oscillator model, in terms of geometric differences between certain vibrations in the diastereomeric forms. Application of the coupled-oscillator formalism allows the determination of a dihedral angle between the coupling vibrations. The results are compared with vibrational coupling employed by other workers in the determination of the vibrational spectra of peptides.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 100
    Digitale Medien
    Digitale Medien
    New York : Wiley-Blackwell
    Biopolymers 23 (1984), S. 1951-1960 
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The conformational equilibria of five β-cellobiose conformers have been studied theoretically in 10 solvents. The stability of the conformers in dilute solution has been compared by using the method that has already been tested for 2-methoxytetrahydropyran, β-maltose, and D-glucose. The solvation energy consists of electrostatic, dispersion, and cavity terms which have been determined from the properties of the solute calculated by the PCILO quantum-chemical method and physicochemical properties of the solvents. The calculated abundance of conformers depends on the solvent (e.g., in dioxane C1:C2:C3:C4:C5 = 60.0:34.1:2.9:2.0:1.0; in dimethylsulfoxide, 75.5:22.1:1.8:0.5:0.2; and in water, 82.2:16.2:1.3:0.2:0.1). The results obtained indicate that the preponderant conformer in the aqueous solution is similar to the one adopted by β-cellobiose in the crystalline form. The role of individual contributions to the solvation energy have been analyzed. Based on the determined abundance of conformers, averaged residual optical activity and nmr parameters have been calculated and compared with observable properties. The marked differences observed between solvent-induced conformational changes for β-cellobiose and β-maltose have been discussed from the viewpoint of the solubility of the cellulose.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...