ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

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
  • Chemistry  (7.254)
  • General Chemistry  (879)
  • Cell & Developmental Biology  (873)
  • 1990-1994
  • 1985-1989  (8.127)
  • 1985  (8.127)
Sammlung
Schlagwörter
Verlag/Herausgeber
Erscheinungszeitraum
  • 1990-1994
  • 1985-1989  (8.127)
Jahr
  • 1
    facet.materialart.
    Unbekannt
    Bond order and charge localization in nucleoside phosphorothioates (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-05-03
    Beschreibung: In the recent literature on nucleoside phosphorothioate anions the structural formulas show a double bond between phosphorus and sulfur and a single bond between phosphorus and oxygen with a negative charge localized on oxygen. However, a review of physical data on these compounds shows the reverse to be the case; that is, in phosphorothioate anions the P-S bond is a single bond with a negative charge localized on sulfur, while the P-O bond order for exocyclic and nonbridging oxygens is greater than 1, approaching 2 in O-alkyl phosphorothioate monoanions and O,O-dialkyl phosphorothioates. The P-O bond orders in phosphorothioate dianions and trianions approach 1 1/2 and 1 1/3, respectively, owing to delocalization of negative charge among two or three oxygens. These conclusions are based on bond lengths obtained from x-ray crystallographic data and electron diffraction, the magnitudes of the effects of 18O on the 31P-nuclear magnetic resonance chemical shifts of phosphorus in nucleoside [18O]phosphorothioates, the pH-dependence of 17O-NMR chemical shifts in [17O]phosphate and [17O]thiophosphate, the vibrational spectra of thiophosphate di- and trianions, and the pKa (dissociation constant) values for phosphoric and thiophosphoric acids.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frey, P A -- Sammons, R D -- GM30480/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1985 May 3;228(4699):541-5.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2984773" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Chemical Phenomena ; Chemistry ; Chemistry, Physical ; Cyclic AMP/metabolism ; Magnetic Resonance Spectroscopy ; Phosphates/metabolism ; Phosphoric Acids/metabolism ; Physicochemical Phenomena ; *Thionucleotides/metabolism
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 2
    facet.materialart.
    Unbekannt
    Dissociation of antitumor potency from anthracycline cardiotoxicity in a doxorubicin analog (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-06-28
    Beschreibung: The search for new congeners of the leading anticancer drug doxorubicin has led to an analog that is approximately 1000 times more potent, noncardiotoxic at therapeutic dose levels, and non-cross-resistant with doxorubicin. The new anthracycline, 3'-deamino-3'-(3-cyano-4-morpholinyl)doxorubicin (MRA-CN), is produced by incorporation of the 3' amino group of doxorubicin in a new cyanomorpholinyl ring. The marked increase in potency was observed against human ovarian and breast carcinomas in vitro; it was not accompanied by an increase in cardiotoxicity in fetal mouse heart cultures. Doxorubicin and MRA-CN both produced typical cardiac ultrastructural and biochemical changes, but at equimolar concentrations. In addition, MRA-CN was not cross-resistant with doxorubicin in a variant of the human sarcoma cell line MES-SA selected for resistance to doxorubicin. Thus antitumor efficacy was dissociated from both cardiotoxicity and cross-resistance by this modification of anthracycline structure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sikic, B I -- Ehsan, M N -- Harker, W G -- Friend, N F -- Brown, B W -- Newman, R A -- Hacker, M P -- Acton, E M -- CA 24543/CA/NCI NIH HHS/ -- CA 32250/CA/NCI NIH HHS/ -- CA 33303/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1985 Jun 28;228(4707):1544-6.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/4012308" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; *Antineoplastic Agents ; Breast Neoplasms/drug therapy ; Cell Line ; Chemical Phenomena ; Chemistry ; Dose-Response Relationship, Drug ; Doxorubicin/adverse effects/*analogs & derivatives/therapeutic use ; Female ; Heart/drug effects ; Humans ; Isoenzymes ; L-Lactate Dehydrogenase/analysis ; Mice ; Myocardium/enzymology ; Ovarian Neoplasms/drug therapy ; Pregnancy
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 3
    facet.materialart.
    Unbekannt
    A potent nonpeptide cholecystokinin antagonist selective for peripheral tissues isolated from Aspergillus alliaceus (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-10-11
    Beschreibung: A new, competitive, nonpeptide cholecystokinin (CCK) antagonist, asperlicin, was isolated from the fungus Aspergillus alliaceus. The compound has 300 to 400 times the affinity for pancreatic, ileal, and gallbladder CCK receptors than proglumide, a standard agent of this class. Moreover, asperlicin is highly selective for peripheral CCK receptors relative to brain CCK and gastrin receptors. Since asperlicin also exhibits long-lasting CCK antagonist activity in vivo, it should provide a valuable tool for investigating the physiological and pharmacological actions of CCK.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chang, R S -- Lotti, V J -- Monaghan, R L -- Birnbaum, J -- Stapley, E O -- Goetz, M A -- Albers-Schonberg, G -- Patchett, A A -- Liesch, J M -- Hensens, O D -- New York, N.Y. -- Science. 1985 Oct 11;230(4722):177-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2994227" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Aspergillus/*metabolism ; Benzodiazepinones/*isolation & purification/pharmacology ; Chemical Phenomena ; Chemistry ; Cholecystokinin/*antagonists & inhibitors/pharmacology/physiology ; Dose-Response Relationship, Drug ; Gallbladder/drug effects ; Guinea Pigs ; Ileum/drug effects ; Pancreas/drug effects ; Rats ; Receptors, Cell Surface/drug effects ; Receptors, Cholecystokinin
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 4
    facet.materialart.
    Unbekannt
    Three-dimensional structure of poliovirus at 2.9 A resolution (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-09-27
    Beschreibung: The three-dimensional structure of poliovirus has been determined at 2.9 A resolution by x-ray crystallographic methods. Each of the three major capsid proteins (VP1, VP2, and VP3) contains a "core" consisting of an eight-stranded antiparallel beta barrel with two flanking helices. The arrangement of beta strands and helices is structurally similar and topologically identical to the folding pattern of the capsid proteins of several icosahedral plant viruses. In each of the major capsid proteins, the "connecting loops" and NH2- and COOH-terminal extensions are structurally dissimilar. The packing of the subunit "cores" to form the virion shell is reminiscent of the packing in the T = 3 plant viruses, but is significantly different in detail. Differences in the orientations of the subunits cause dissimilar contacts at protein-protein interfaces, and are also responsible for two major surface features of the poliovirion: prominent peaks at the fivefold and threefold axes of the particle. The positions and interactions of the NH2- and COOH-terminal strands of the capsid proteins have important implications for virion assembly. Several of the "connecting loops" and COOH-terminal strands form prominent radial projections which are the antigenic sites of the virion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hogle, J M -- Chow, M -- Filman, D J -- AI-20566/AI/NIAID NIH HHS/ -- AI-22346/AI/NIAID NIH HHS/ -- NS-07078/NS/NINDS NIH HHS/ -- R01 AI020566/AI/NIAID NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1985 Sep 27;229(4720):1358-65.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2994218" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Antigens, Viral/immunology ; Capsid/physiology ; Chemical Phenomena ; Chemistry ; HeLa Cells/microbiology ; Mutation ; Poliovirus/physiology/*ultrastructure ; Protein Conformation ; Virus Replication ; X-Ray Diffraction
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 5
    facet.materialart.
    Unbekannt
    Qinghaosu (artemisinin): an antimalarial drug from China (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-05-31
    Beschreibung: The herb Artemisia annua has been used for many centuries in Chinese traditional medicine as a treatment for fever and malaria. In 1971, Chinese chemists isolated from the leafy portions of the plant the substance responsible for its reputed medicinal action. This compound, called qinghaosu (QHS, artemisinin), is a sesquiterpene lactone that bears a peroxide grouping and, unlike most other antimalarials, lacks a nitrogen-containing heterocyclic ring system. The compound has been used successfully in several thousand malaria patients in China, including those with both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum. Derivatives of QHS, such as dihydroqinghaosu, artemether, and the water-soluble sodium artesunate, appear to be more potent than QHS itself. Sodium artesunate acts rapidly in restoring to consciousness comatose patients with cerebral malaria. Thus QHS and its derivatives offer promise as a totally new class of antimalarials.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Klayman, D L -- New York, N.Y. -- Science. 1985 May 31;228(4703):1049-55.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3887571" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; *Antimalarials ; *Artemisinins ; Brain Diseases/therapy ; Chemical Phenomena ; Chemistry ; Humans ; Liver/metabolism ; Malaria/*drug therapy ; Medicine, Chinese Traditional ; Metabolic Clearance Rate ; Plants, Medicinal/analysis ; Plasmodium berghei ; Plasmodium falciparum ; *Sesquiterpenes/isolation & purification/metabolism/therapeutic use/toxicity
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 6
    facet.materialart.
    Unbekannt
    Sculpting horizons in organic chemistry (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-02-22
    Beschreibung: Organic chemistry as a discipline derives from and impacts on the biological and abiological world in which we live. Its challenges lie in the areas of structure, reactivity, techniques, and concepts. Powerful structural tools reveal structures from biology that range from control of insect development and behavior to whole new metabolic pathways in humans. Unnatural products create beautiful new molecular shapes whose properties cannot be predicted as well as catalysts that function with enzyme-like control. From structure flows reactivity. Exploration of known reactions points to new directions, and development of new reactions offers the opportunity of streamlined synthetic design. Emerging new techniques offer new dimensions for performing and studying reactions as well as the hope for developing new ones. Merging disparate facts into unified concepts increases predictive capabilities. The extraordinary difficulty of finding the resultant of many small effects may obscure the presence of general theories, creates the art in the practice of the science, and challenges the practitioner. From these general themes derives the quest for selectivity--chemo-, regio-, diastereo-, and enantio-. An examination of the fundamental underpinnings of the applications of organic chemistry reveals that, while impressive strides have been made, the science is best described as being between infancy and childhood. The cross-fertilization between organic chemistry and molecular biology vividly illustrates a merging of chemistry and biology.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Trost, B M -- New York, N.Y. -- Science. 1985 Feb 22;227(4689):908-16.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3969569" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Alkylation ; Animals ; Chemical Phenomena ; Chemistry ; *Chemistry, Organic ; Enzymes ; Humans ; Insects ; Mammals ; Organic Chemistry Phenomena ; Research ; Stereoisomerism
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 7
    facet.materialart.
    Unbekannt
    Hernandulcin: an intensely sweet compound discovered by review of ancient literature (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-01-25
    Beschreibung: Ancient Mexican botanical literature was systematically searched for new plant sources of intensely sweet substances. Lippia dulcis Trev., a sweet plant, emerged as a candidate for fractionation studies, and hernandulcin, a sesquiterpene, was isolated and judged by a human taste panel as more than 1000 times sweeter than sucrose. The structure of the sesquiterpene was determined spectroscopically and confirmed by chemical synthesis. Hernandulcin was nontoxic when administered orally to mice, and it did not induce bacterial mutation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Compadre, C M -- Pezzuto, J M -- Kinghorn, A D -- Kamath, S K -- N01-DE-02425/DE/NIDCR NIH HHS/ -- New York, N.Y. -- Science. 1985 Jan 25;227(4685):417-9.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3880922" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Bibliography as Topic ; Botany/history ; Chemistry ; History, 16th Century ; Humans ; Magnetic Resonance Spectroscopy ; Mexico ; Mice ; Molecular Conformation ; Mutagenicity Tests ; *Plants/analysis ; *Sesquiterpenes/chemical synthesis/isolation & purification/toxicity ; *Sweetening Agents/chemical synthesis/history/isolation & purification/toxicity
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 8
    facet.materialart.
    Unbekannt
    Computer-assisted analysis in organic synthesis (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-04-26
    Beschreibung: The planning of alternative routes for the synthesis of complex organic molecules has been facilitated by the formulation of guiding strategies that can be applied to a broad range of problems. Analysis of organic synthesis can be carried out in the retrosynthetic direction, opposite to the actual process of chemical synthesis, or bidirectionally, that is, as a combined retrosynthetic and synthetic search. An interactive computer program is described which utilizes the general strategies of retrosynthetic analysis and an appropriate database to generate pathways of chemical intermediates for chemical synthesis of a particular target structure. Computer graphics and standard chemical structures are used for man-machine communication.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Corey, E J -- Long, A K -- Rubenstein, S D -- New York, N.Y. -- Science. 1985 Apr 26;228(4698):408-18.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3838594" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Chemical Phenomena ; Chemistry ; Chemistry, Organic/*methods ; *Computers ; Forecasting ; Software
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 9
    facet.materialart.
    Unbekannt
    Dynamics and conformational energetics of a peptide hormone: vasopressin (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-03-15
    Beschreibung: A theoretical methodology for use in conjunction with experiment was applied to the neurohypophyseal hormone lysine vasopressin for elucidation of its accessible molecular conformations and associated flexibility, conformational transitions, and dynamics. Molecular dynamics and energy minimization techniques make possible a description of the conformational properties of a peptide in terms of the precise positions of atoms, their fluctuations in time, and the interatomic forces acting on them. Analysis of the dynamic trajectory of lysine vasopressin shows the ability of a flexible peptide hormone to undergo spontaneous conformational transitions. The excursions of an individual phenylalanine residue exemplify the dynamic flexibility and multiple conformational states available to small peptide hormones and their component residues, even within constraints imposed by a cyclic hexapeptide ring.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hagler, A T -- Osguthorpe, D J -- Dauber-Osguthorpe, P -- Hempel, J C -- New York, N.Y. -- Science. 1985 Mar 15;227(4692):1309-15.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3975616" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Chemical Phenomena ; Chemistry ; Chemistry, Physical ; Energy Metabolism ; Hydrogen Bonding ; Lypressin/*metabolism ; Phenylalanine/metabolism ; Physicochemical Phenomena ; Protein Conformation
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 10
    facet.materialart.
    Unbekannt
    Single-carbon chemistry of acetogenic and methanogenic bacteria (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-03-08
    Beschreibung: Methanogenic and acetogenic bacteria metabolize carbon monoxide, methanol, formate, hydrogen and carbon dioxide gases and, in the case of certain methanogens, acetate, by single-carbon (C1) biochemical mechanisms. Many of these reactions occur while the C1 compounds are linked to pteridine derivatives and tetrapyrrole coenzymes, including corrinoids, which are used to generate, reduce, or carbonylate methyl groups. Several metalloenzymes, including a nickel-containing carbon monoxide dehydrogenase, are used in both catabolic and anabolic oxidoreductase reactions. We propose biochemical models for coupling carbon and electron flow to energy conservation during growth on C1 compounds based on the carbon flow pathways inherent to acetogenic and methanogenic metabolism. Biological catalysts are therefore available which are comparable to those currently in use in the Monsanto process. The potentials and limitations of developing biotechnology based on these organisms or their enzymes and coenzymes are discussed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zeikus, J G -- Kerby, R -- Krzycki, J A -- 144-T263/PHS HHS/ -- New York, N.Y. -- Science. 1985 Mar 8;227(4691):1167-73.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3919443" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Acetates/*metabolism ; Acetobacter/metabolism ; Bacteria/*metabolism ; Carbon Dioxide/metabolism ; Carbon Monoxide/metabolism ; Chemical Phenomena ; Chemistry ; Clostridium/metabolism ; Eubacterium/metabolism ; Euryarchaeota/*metabolism ; Formates/metabolism ; Methane/metabolism ; Methanol/metabolism
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 11
    facet.materialart.
    Unbekannt
    Trypanothione: a novel bis(glutathionyl)spermidine cofactor for glutathione reductase in trypanosomatids (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-03-22
    Beschreibung: Glutathione reductase from trypanosomes and leishmanias, unlike glutathione reductase from other organisms, requires an unusual low molecular weight cofactor for activity. The cofactor was purified from the insect trypanosomatid Crithidia fasciculata and identified as a novel glutathione-spermidine conjugate, N1,N8-bis(L-gamma-glutamyl-L-hemicystinyl-glycyl)spermidine, for which the trivial name trypanothione is proposed. This discovery may open a new chemotherapeutic approach to trypanosomiasis and leishmaniasis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fairlamb, A H -- Blackburn, P -- Ulrich, P -- Chait, B T -- Cerami, A -- 1 R01 A127429/PHS HHS/ -- 1 R01 AI19428/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1985 Mar 22;227(4693):1485-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3883489" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Chemical Phenomena ; Chemistry ; Coenzymes/analysis/*isolation & purification/metabolism ; Crithidia/*enzymology ; Glutathione/*analogs & derivatives/analysis/isolation & purification/metabolism ; Glutathione Reductase/*metabolism ; Leishmania/*enzymology ; Oxidation-Reduction ; Spermidine/*analogs & derivatives/analysis/isolation & purification/metabolism ; Terminology as Topic ; Trypanosoma/*enzymology ; Trypanosoma brucei brucei/enzymology ; Trypanosoma cruzi/enzymology
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 12
    facet.materialart.
    Unbekannt
    Mechanisms of coenzyme B12-dependent rearrangements (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-02-22
    Beschreibung: Coenzyme B12 serves as a cofactor in various enzymatic reactions in which a hydrogen atom is interchanged with a substituent on an adjacent carbon atom. Measurement of the dissociation energy of the coenzyme's cobalt-carbon bond and studies of the rearrangement of model free radicals related to those derived from methylmalonyl-coenzyme A suggest that these enzymatic reactions occur through homolytic dissociation of the coenzyme's cobalt-carbon bond, abstraction of a hydrogen atom from the substrate by the coenzyme-derived 5'-deoxyadenosyl radical, and rearrangement of the resulting substrate radical. The only role thus far identified for coenzyme B12 in these reactions--namely, that of a free radical precursor--reflects the weakness, and facile dissociation, of the cobalt-carbon bond.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Halpern, J -- New York, N.Y. -- Science. 1985 Feb 22;227(4689):869-75.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2857503" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Carbon/metabolism ; Chemical Phenomena ; Chemistry ; Chemistry, Physical ; Cobalt/metabolism ; Cobamides/*metabolism ; Energy Metabolism ; Free Radicals ; Methylmalonyl-CoA Mutase/metabolism ; Physicochemical Phenomena
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 13
    facet.materialart.
    Unbekannt
    The structure of arthropod hemocyanins (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-08-09
    Beschreibung: Hemocyanins are large multi-subunit copper proteins that transport oxygen in many arthropods and molluscs. Comparison of the amino acid sequence data for seven different subunits of arthropod hemocyanins from crustaceans and chelicerates shows many highly conserved residues and extensive regions of near identity. This correspondence can be matched closely with the three domain structure established by x-ray crystallography for spiny lobster hemocyanin. The degree of identity is particularly striking in the second domain of the subunit that contains the six histidines which ligate the two oxygen-binding copper atoms. The polypeptide architecture of spiny lobster hemocyanin appears to be the same in all arthropods. This structure must therefore be at least as old as the estimated time of divergence of crustaceans and chelicerates, about 540 to 600 million years ago.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Linzen, B -- Soeter, N M -- Riggs, A F -- Schneider, H J -- Schartau, W -- Moore, M D -- Yokota, E -- Behrens, P Q -- Nakashima, H -- Takagi, T -- GM 21314/GM/NIGMS NIH HHS/ -- GM 28410/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1985 Aug 9;229(4713):519-24.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/4023698" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Arachnida/genetics ; *Arthropods/genetics ; Binding Sites ; Biological Evolution ; Chemical Phenomena ; Chemistry ; Copper ; Crustacea/genetics ; *Hemocyanin/genetics ; Models, Molecular ; Protein Conformation ; Species Specificity
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 14
    facet.materialart.
    Unbekannt
    [2 + 2] photocycloadditions in the synthesis of chiral molecules (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-02-22
    Beschreibung: A strategy for the synthesis of chiral molecules that receives growing popularity among organic chemists employs the photochemically mediated [2 + 2] cycloaddition reaction. These reactions can be performed on a multigram scale and often proceed with high yield and with stereocontrol. These features, in combination with the useful properties of the four-membered ring photoproducts in subsequent chemical transformations, make them attractive options in the early stage of a synthesis design. Various combinations of unsaturated functional groups can participate in this reaction process. Accordingly, these chemical reactions can be economical solutions to problems relating to the synthesis of a variety of target molecules.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schreiber, S L -- GM-32527/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1985 Feb 22;227(4689):857-63.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/4038558" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Anti-Bacterial Agents/chemical synthesis ; Antifungal Agents/chemical synthesis ; Chemical Phenomena ; Chemistry ; Cockroaches ; Female ; Furans/chemical synthesis ; Lactones/chemical synthesis ; Male ; Mycotoxins/chemical synthesis ; *Photochemistry ; Pyrones/chemical synthesis ; Sex Attractants/chemical synthesis/isolation & purification ; Stereoisomerism
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 15
    facet.materialart.
    Unbekannt
    Computerized pattern recognition: a new technique for the analysis of chemical communication (1985)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1985-04-12
    Beschreibung: Computerized pattern recognition techniques can be applied to the study of complex chemical communication systems. Analysis of high resolution gas chromatographic concentration patterns of the major volatile components of the scent marks of a South American primate, Saguinus fuscicollis, demonstrates that the concentration patterns can be used to predict the gender and subspecies of unknown donors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, A B 3rd -- Belcher, A M -- Epple, G -- Jurs, P C -- Lavine, B -- 5 T32 NSO7176-03/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1985 Apr 12;228(4696):175-7.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/3975636" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Chemical Phenomena ; Chemistry ; Chromatography, Gas ; *Computers ; Female ; Male ; *Pattern Recognition, Automated ; Pheromones/*physiology ; Saguinus/physiology ; Scent Glands/physiology ; Sex Attractants/*physiology ; Structure-Activity Relationship
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 16
    Digitale Medien
    Digitale Medien
    High-speed cinematographic analysis of the movement of Chlamydomonas (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 251-263 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Chlamydomonas ; movement ; flagellar beat ; stigma ; high-speed microcinematography ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Using high-speed microcinematography (100-500 f/s) the movement of Chlamydomonas reinhardtii mutant 622 E has been studied with frame-by-frame analysis. The stigma lies in the cell equator, displaced out of the flagellar plane anticlockwise by an angle of about 45°. During forward movement the cells rotate anticlockwise about their long axis with a frequency of 1.4-2 Hz (maximum 2.5 Hz). The rotation is caused by a lateral component of 3-dimensional beating of the flagella during the effective strokes. The helical swimming path is a result of an unequal flagellar beating. This is normally synchronous, but synchrony is interrupted from time to time by an additional beat of the outward directed flagellum, in our study one after about every twenty beats on average. These results are discussed and compared with the results published by other groups.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050307
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 17
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050501
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 18
    Digitale Medien
    Digitale Medien
    Newt lung ciliated cell models: Effect of MgATP on beat frequency and waveforms (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 377-392 
    Details
    ISSN: 0886-1544
    Schlagwort(e): newt ; lung ; cilia ; beat frequency ; waveform ; models ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Highly coupled newt lung ciliated cell models were used to study the effects of MgATP concentration on ciliary beat frequency and waveform. Models were prepared from ciliated lung cells of the newt Taricha granulosa by trypsin dissociation of the epithelium, demembranation with Triton X-100, and reactivation with MgATP, as described previously [Weaver and Hard, 1985]. Beat frequencies were measured stroboscopically. Ciliary waveforms of reactivated models and intact mucociliary epithelial sheets were determined by single frame analysis of high-speed movies. Waveform parameters calculated included the durations of the effective and recovery strokes, the angular velocities of the ciliary base and tip, the position of the bend along the ciliary shaft during the recovery stroke, the velocity of recovery stroke bend propagation, and the ratio of the duration of recovery stroke bend propagation to the duration of the recovery stroke itself. We found that beat frequency varied biphasically in response to MgATP at 21°C, as shown previously for isolated, individual, newt lung axonemes. Apparent Fmax (maximum beat frequency) and Km values of 25 Hz and 0.14 mM, and 35 Hz and 0.47 mM, respectively, were obtained for each linear segment of the biphasic double reciprocal plot. Demembranation did not alter either ciliary waveform or the pattern of coordination. In this system, metachrony is antilaeoplectic and ciliary waveform appears to be regulated independent of beat frequency.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050503
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 19
    Digitale Medien
    Digitale Medien
    A model for fast axonal transport (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 507-527 
    Details
    ISSN: 0886-1544
    Schlagwort(e): axonal transport ; microtubules ; organelles ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A model for fast axonal transport is developed in which the essential features are that organelles may interact with mechanochemical cross-bridges that in turn interact with microtubules, forming an organelle-engine-microtubule complex which is transported along the microtubules. Computer analysis of the equations derived to describe such a system show that most of the experimental observations on fast axonal transport can be simulated by the model, indicating that the model is useful for the interpretation and design of experiments aimed at clarifying the mechanism of fast axonal transport.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050607
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 20
    Digitale Medien
    Digitale Medien
    A Ca2+ insensitive actin-crosslinking protein from Dicytostelium discoideum (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 529-543 
    Details
    ISSN: 0886-1544
    Schlagwort(e): actin ; regulatory protein ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: We have isolated a 30,000-dalton protein from Dictyostelium which cosedimented with and affected the low shear viscosity of actin. At low concentrations, this protein increased the low shear viscosity to greater than that of the actin control, whereas higher concentrations decreased viscosity. The viscosity decrease correlated with the formation of actin filament bundles, as seen electron microscopically. This protein resembled a previously reported actin-binding protein from Dictyostelium [Fechheimer and Taylor, 84, J Biol Chem 259:4514] in electrophoretic mobility, Stokes radius, and ability to crosslink filaments, but was shown to be different by peptide mapping, lack of immunologic crossreactivity, and lack of sensitivity to calcium.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050608
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 21
    Digitale Medien
    Digitale Medien
    A Method for quantifying F-Actin in chemotactic peptide activated neutrophils: Study of the effect of tBOC peptide (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 545-557 
    Details
    ISSN: 0886-1544
    Schlagwort(e): neutrophils ; cytoskeleton ; actin polymerization ; NBDphallacidin ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The studies presented here characterize a simple, quantitative NBDphallacidin extraction assay for determining the F-actin content of fMLP-activated neutrophils. The NBDphallacidin extraction assay is based upon the specificity of NBDphallacidin binding to F-actin and the solubility of NBDphallacidin in methanol. Cells are fixed, permeabilized, and stained with NBDphallacidin; the cells are then pelleted, the bound NBDphallacidin is extracted into methanol, and the RFI (excite 465; emit 535) of the solution is determined. Binding of NBDphallacidin to neutrophils is saturable and 90% of bound NBDphallacidin is displaced by nonfluorescent phalloidin. The extraction of bound NBDphallacidin into methanol is complete and the excitation/emission characteristics of NBDphallacidin are not altered by extraction. The assay is relatively inexpensive, applicable to the study of cells in suspension or on substratum, allows kinetic studies with 5-10s time resolution, and is not affected by the shape of the cell or the distribution of the probe. We used the NBDphallacidin extraction assay to study the kinetics of fMLP-induced change in the F-actin content of neutrophils and the effect of tBOC peptide, an inhibitor of fMLP binding, on these changes. The extraction assay reveals a rapid, sequential fMLP-induced increase followed by a decrease in F-actin content. The tBOC peptide inhibits fMLP-induced actin polymerization. Addition of tBOC during fMLP-induced polymerization or at times when F-actin content is maximal enhances F-actin depolymerization. The rate of F-actin depolymerization is ≥ fourfold faster in the presence than in the absence of tBOC. The results show that (1) The NBDphallacidin extraction assay is useful for studying the kinetics of change in F-actin content of nonmuscle cells; (2) fMLP receptor occupancy is required for fMLP-dependent polymerization but not depolymerization; and (3) both the actin polymerizing and depolymerizing processes are active in the cell within 5 s after fMLP stimulation. Implications of these observations for understanding the observed increase and, then, decrease in F-actin content of fMLP-activated cells are discussed.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050609
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 22
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050101
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 23
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050301
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 24
    Digitale Medien
    Digitale Medien
    Orthokinetic and klinokinetic responses of human polymorphonuclear leucocytes (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 447-461 
    Details
    ISSN: 0886-1544
    Schlagwort(e): chemokinesis ; orthokinesis ; klinokinesis ; polymorphonuclear leucocytes ; locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Evidence is presented to show that klinokinesis, which was previously demonstrated in bacteria and amoeba only, may also occur in metazoan cells. The chemotactic peptide formyl-Met-Leu-Phe (fMLP) elicited orthokinetic and klinokinetic responses of human blood-borne polymorphonuclear leucocytes (PMNs) under the test conditions used. Increased speed (orthokinesis) was due to an increase in the proportion of migrating cells as well as in the speed of the locomoting subset. The klinokinetic effect was manifested by a decrease in the klinolocomotion index, the mean angle of changes in direction ≥ 90°, and the frequency of turns ≥ 90°. The klinolocomotion index was inversely related to speed. This explains the synergistic effect of klinokinesis and orthokinesis in this system. Colchicine alone had and orthokinetic effect which was exclusively due to alterations in the proportion of migrating cells and it altered the turning behaviour without exerting a klinokinetic effect. However, colchicine had marginal orthokinetic and klinokinetic effects on fMLP-stimulated cells resulting in reduced translocation. The relationship between klinokinesis and mean angle or frequency of turns has been analysed. Klinokinesis was a substantial though not the major element of the chemokinetic response to fMLP under the conditions used. No other metazoan cells have been shown to possess such a complete pattern of responses, including orthokinesis, klinokinesis, and chemotaxis, which regulate locomotion.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050603
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 25
    Digitale Medien
    Digitale Medien
    Isolation of newt lung ciliated cell models: Characterization of motility and coordination thresholds (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 355-375 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Newt ; lung ; cilia ; cell models ; ciliary coordination ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Demembranated ciliated cell models are useful for studying mechanisms responsible for the regulation of ciliary coordination and waveform. This paper describes procedures for isolating ciliated cells from the newt, Taricha granulosa, by trypsin dissociation, their subsequent demembranation by Triton X-100, and their reactivation with MgATP to produce highly motile, coordinated, ciliated cell models. Reactivation of cell models with a high degree of mechanochemical coupling depended on avoiding mechanical damage and maintaining optimal conditions during all stages of isolation and reactivation. Highly motile models were prepared from cells incubated in trypsin, treated briefly with EDTA, separated by gentle agitation, and concentrated by centrifugation at low gravitational forces. Optimal demembranation and reactivation conditions were similar to those described previously for isolated newt lung axonemes. Under these conditions, nearly 100% of the models were reactivated when provided with MgATP and 90-95% beat with coordinated waves. The ciliary tufts beat at frequencies within the range measured in living cells and their reactivated motility was stable for at least 30 min at constant MgATP. These highly coupled models were used to show (1) that development of coordination in the ciliary tuft occurs at a higher substrate concentration range (10-25 μM) than that required to initiate motility per se (2-10 μM); (2) that outer dynein arms may not contribute to beat frequency at substrate concentrations below 35 μM; and (3) that vanadate has effects both on beat frequency and coordination of the tufts.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050502
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 26
    Digitale Medien
    Digitale Medien
    An approach to digital image analysis of bending shapes of eukaryotic flagella and cilia (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 475-489 
    Details
    ISSN: 0886-1544
    Schlagwort(e): digital image processing ; flagella ; cilia ; bends ; Hemicentrotus ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A novel method of digital image analysis of the bends of eukaryotic flagella and cilia was devised. In the analysis system, all image pixels were systematically extracted and processed to measure angular direction and curvature. Simulation experiments on theoretical model pictures of flagella with sine-generated or arcstraight line bending waves demonstrated that the method can be used with considerable high accuracy. This method then revealed abrupt changes in slope of the curvature in sperm flagella and embryo cilia of the sea urchin, Hemicentrotus pulcherrimus. This indicates that the digital image processing used may be helpful in the study of flagellar and ciliary movements.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050605
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 27
    Digitale Medien
    Digitale Medien
    Reorientation of the golgi apparatus and the microtubule-organizing center inside macrophages subjected to a chemotactic gradient (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 17-29 
    Details
    ISSN: 0886-1544
    Schlagwort(e): cell motility ; membrane recycling ; immunofluorescence microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Mouse peritoneal macrophages subjected to gradients of activated mouse serum were found by immunofluorescence observations to have their Golgi apparatus and their microtubule-organizing center largely oriented in the direction of the gradient. By analogy with similar results obtained with motile fibroblasts, it is proposed that these two organelles are rapidly and coordinately reoriented inside the macrophages in order to direct the insertion of new membrane mass, via vesicles derived from the Golgi apparatus, into the leading edge of the cell. Consistent with the importance of such membrane insertion to cell migration, we found that the ionophore monensin, an inhibitor of Golgi functions, inhibited cell motility in the chemostactic gradient. It was further shown that several inhibitors of chemotaxis (monensin, cytochalasin D, cycloheximide) did not inhibit the reorientation of the Golgi apparatus/microtubule-organizing center in cells exposed to a chemotactic gradient, and that the reorientation required extracellular Ca+2.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050103
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 28
    Digitale Medien
    Digitale Medien
    Obituary (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. i 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050202
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 29
    Digitale Medien
    Digitale Medien
    An investigation of the involvement of cytoskeletal structures and secretion in gliding motility of the marine diatom, Amphora coffeaeformis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 103-122 
    Details
    ISSN: 0886-1544
    Schlagwort(e): gliding ; cell motility ; cytoskeleton ; diatoms ; capping ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Gliding motility was investigated in the marine diatom, Amphora coffeaeformis. Ultrastructural, biochemical, and pharmacological protocols were employed to probe the possible involvement of cytoskeletal proteins and a secretory process in gliding motility. Motility rate was measured using a video recording apparatus, and the effects of various cytoskeleton-disrupting drugs on motility were tested. Cytochalasins D and E, podophyllotoxin, and vinblastine (all at 25 μUg/ml) reversibly inhibited motility, as did monensin (10 μUM) and pronase (25 μUg/ml). Biochemical protein analysis of whole-cell extracts by one- and two-dimensional polyacrylamide gel electrophoresis revealed polypeptides comigrating with rabbit skeletal muscle actin and bovine brain tubulin; however, specific assays used to separate actin from whole-cell preparations gave ambiguous results. Ultrastructural studies revealed the presence of extracellular material between the raphe canal and the substratum in motile cultures. An assay was devised for the detection of radioactively labeled material (MW 〉 1800 Daltons) released by motile cultures into the culture medium. When cultures were treated with either an anticytoskeletal drug or monensin, motility was inhibited while the amount of measured radioactivity increased over solvent-treated control groups. The results from this study indicate possible roles for both actin- and tubulin-based structures in gliding motility of Amphora. Though secretion may be necessary for gliding to occur, its exact relationship to motility was not deduced. The data obtained in this study are compatible with a theory for the mechanism of gliding which involves the surface translocation of externally exposed membrane proteins against an immobile matrix of substratum-attached secreted material to generate the force required for movement.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050204
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 30
    Digitale Medien
    Digitale Medien
    Chromosome movement during meiotic prophase in crane-fly spermatocytes: III. Microtubules and the effects of Colcemid, nocodazole, and vinblastine (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 393-413 
    Details
    ISSN: 0886-1544
    Schlagwort(e): chromosome movement ; Colcemid ; nocodazole ; meiotic prophase ; microtubules ; vinblastine ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The effects of Colcemid, nocodazole, and vinblastine on microtubules and on the movement of chromosomes during late diakinesis were investigated in spermatocytes of the crane fly Nephrotoma suturalis. The kinds of movements observed in untreated cells - sex bivalent rotations, sex bivalent excursions, and rotations and positional changes of autosomal bivalents - also were observed in drug-treated cells. These results were obtained in living cells in which the disruption and inhibition of microtubule assembly had been confirmed with polarized light microscopy. Effects of Colcemid and nocodazole also were assessed in fixed cells using electron microscopy. The results are in agreement with a hypothesis that microtubules are not a force-generating component of the molecular machinery that brings about prophase movements.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050504
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 31
    Digitale Medien
    Digitale Medien
    Use of multiple monoclonal antibodies to characterize the major microtubule-associated protein in sea urchin eggs (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 431-446 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Microtubules assembled from sea urchin eggs with the use of taxol contain a 77,000-dalton protein as the major nontubulin component [Vallee and Bloom (1983): Proc Natl. Acad. Sci. U.S.A. 80:6259-6263]. We have raised five monoclonal antibodies to this protein to aid in its characterization. Immunoblot analysis of the sea urchin microtubule purification fractions indicated that the protein copurified quantitatively with microtubules. All five antibodies stained the mitotic spindle of dividing sea urchin eggs by immunofluorescence microscopy, indicating that the protein was a component of the mitotic spindle and suggesting that it was actually localized on microtubules in vivo. Immunofluorescent staining of higher resolution was observed in a subpopulation of the coelomic cells found in adult sea urchins, confirming that the 77,000-dalton protein is indeed present on microtubules in vivo. Because taxol was not used for the immunofluorescence experiments, we conclude that the microtubule-associated protein (MAP)-like behavior of the 77,000-dalton protein in vitro was not induced artifactually by taxol. To determine whether this protein is a component of sea urchin microtubules in general, cilia obtained from blastula stage embryos and sperm tail flagella were analyzed with the antibodies. The protein was undetectable by both immunoblot analysis and immunofluorescence microscopy in both preparations of axonemal microtubules. These results indicated that the 77,000-dalton MAP is restricted to cytoplasmic and mitotic microtubules in the sea urchin. Furthermore, in view of its particular abundance in embryos, whose microtubules are devoted substantially to mitosis, the 77,000-dalton MAP is likely to play an important role in regulating the activity of mitotic spindle microtubules in the sea urchin.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050602
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 32
    Digitale Medien
    Digitale Medien
    The locomotion of dissociated sponge cells: A cell-by-cell, time-lapse film analysis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 463-473 
    Details
    ISSN: 0886-1544
    Schlagwort(e): sponge dissociates ; cell migration ; time-lapse analysis ; cell aggregation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The production of both lamellipodia and peculiar thin protuberances (scleropodia) characterizes the preaggregative motility of cells after dissociation of the sponge Clathrina.The locomotory paths taken by cells before aggregation were recorded by time-lapse microcinematography. Changes of direction in successive 50-s time intervals and 50-s mean velocities of each cell were both taken into account as statistical variables. Their distributions give probability density curves that seem to fit bilateral exponential functions. The analysis of the angles of turn indicates a tendency for the cells to persist in their direction of motion and to make counter-clockwise turns. Implications of such in vitro cellular behaviors in aggregative and in vivo processes are suggested.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050604
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 33
    Digitale Medien
    Digitale Medien
    The antagonistic effects of 5-hydroxytryptamine and methylxanthine on the gill cilia of mytilus edulis (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 293-309 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Mytilus edulis ; 5-hydroxytryptamine ; lateral cilia ; laterofrontal cirri ; beat frequency ; methylxanthine ; filter-feeding ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The laterofrontal (LF) cirri on isolated gill filaments of Mytilus edulis, prepared in natural seawater, are active and initially beat with an average frequency of about 8 Hz (with a range of 6-14 Hz). However, the lateral (L) cilia on these filaments are arrested in a position at the end of their recovery stroke. Perfusion of the filament with artificial seawater (ASW), with or without 1% ethanol, has little or no biological effect on the activity of the LF cirri, although a transitory decrease in frequency often accompanies the perfusion process. The L cilia remain arrested during perfusion with ASW. The exposure of the gill to low levels of 5-hydroxytryptamine (5HT) (10-8 〈 5HT 〈 10-7 M) has no effect on the activity of the LF cirri but stimulates the L cilia to beat. Exposure to higher concentrations of 5HT (〉 10-7 M) elevates the beat frequency of the L cilia and simultaneously inhibits the activity of the LF cirri, leading to their arrest in a position at the end of the effective stroke. This arrest of the LF cirri occurs as the L cilia attain a 5HT-induced beat frequency between 12 to 14 Hz. The influence of 5HT on the L cilia and the LF cirri can be reversibly mimicked or enhanced by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX). A concentration of 0.5 mM IBMX mimics low 5HT concentrations (about 10-7 M) by stimulating the L cilia to beat without affecting the beat frequency of the LF cirri. A combimation of 10-7 M 5HT and 0.5 mM IBMX in ASW mimics high (〉 10-6 M) 5HT concentrations by arresting the LF cirri and increasing the beat frequency of the L cilia. Under these conditions, the threshold of the LF cirri arrest response is again found to occur as the L cilia attain a beat frequency of 12 - 14Hz. These results suggest that the mechanisms of LF cirri arrest and L cilia activation are mediated by 5HT -induced changes in intracellular cyclic AMP levels.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050403
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 34
    Digitale Medien
    Digitale Medien
    Live and reactivated motility in the 9 + 0 flagellum of Anguilla sperm (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 333-350 
    Details
    ISSN: 0886-1544
    Schlagwort(e): eel sperm ; 9+0 flagellum ; motility ; helicoidal bending ; reactivation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The sperm flagella of the eel, Anguilla anguilla, are capable of vigorous motion in spite of having an axoneme with reduced structure that lacks the outer dynein arms, radial spokes and spoke heads, the two central tubules and the central tubule projections that are all part of the standard “9+2” axoneme. These sperm progress forward rapidly as a result of the propagation of helicoidal waves distally along the flagellum. Their flagellar beat frequencies are high, 93 Hz at 21°C, and they roll at a frequency of about 19 Hz. Eel sperm could be demembranated with Nonidet P-40 and reactivated with MgATP2- in 0.22 M K acetate at pH 8.1. The reactivated motility closely resembles that of the live sperm, with a beat frequency of 69 Hz, but the demembranated flagella are unusually fragile, and commonly disintegrate by a combination of splitting, coiling, and sliding within a few minutes. Little reactivation is obtained if acetate is replaced by Cl- in the reactivating medium. The Michaelis constant for beat frequency (0.2 mM) is similar to that obtained for several “9+2” flagella. These sperm, however, appear to lack the mechanism by which Ca2+ regulates waveform. Our results indicate that eel sperm flagella, which at rest are straight, are induced to bend helicoidally by ATP, as the result of sliding between tubules that is blocked at both the base and tip of the organelle. The flagellar waveform consists of a series of planar bends separated by short regions of right-handed twist, which give it an overall left-handed helicoidal form.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050406
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 35
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050601
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 36
    Digitale Medien
    Digitale Medien
    Alpha actinin distribution and extracellular matrix products during somitogenesis and neurulation in the chick embryo (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 491-506 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Somitogenesis ; neurulation ; alpha-actinin ; morphogenesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: A discrete stage in two different morphogenetic processes has been examined employing fluorescently labelled alpha-actinin as a probe to localize native alpha-actinin and antibodies to localize fibronectin and collagen type I. The stage of somitogenesis examined is the transition from the compact mesenchymal somitic mass to the epithelial somitic vesicle (ie, epithelialization of the somite). The stage of neurulation examined is the transition from the relatively flat neuroepithelium to the approximation of the neural folds. Before these morphogenetic movements begin, the neuroepithelium is sitting upon a basal lamina and interstitial collagen, and the somite is surrounded by a meshwork of interstitial collagen. During both of these processes, the cells become narrowed at their apices in the region of the tissue that is becoming concave, and alpha-actinin is localized in the apices. The localization of intracellular alpha-actinin and extracellular fibronectin, and the distribution of collagen, suggest that there is a coordinated appearance and distribution of these molecules that is temporally associated with these discrete morphogenetic events.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050606
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 37
    Digitale Medien
    Digitale Medien
    An EHNA-senstive ATPase in unfertilized sea urchin eggs (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 61-75 
    Details
    ISSN: 0886-1544
    Schlagwort(e): dynein ; erythro-9-[3-2-(hydroxynonyl)]adenine (EHNA) ; ATPase ; inhibition ; axoneme ; cytoplasm ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: In current purification strategies, affinity for microtubules or calmodulin is used to identify and purify cytoplasmic dynein-like ATPase from cell-free extracts of unfertilized sea urchin eggs. However, affinity purification procedures, though they define dynein-like ATPase activity, have not yet proven to be quantitative. An alternative purification strategy capable of producing a high yield of enzyme would require a specific assay in order to monitor cytoplasmic dynein purity at each step.In this study, we make a detailed comparison of the effects of EHNA on 22 different ATP-metabolizing enzyme activities, including 13 Mg++-ATPases. We isolate cytoplasmic dynein-like ATPase activity from three species of sea urchin eggs and sperm and show by means of dose-response curves that their sensitivities to inhibition by EHNA are very similar to one another. We demonstrate further that the EHNA dose-response characteristics of fourteen other ATP-metabolizing enzyme activities, including seven nondynein Mg++-ATPases, differ quantitatively from those of dynein-like ATPases.In studies of three other agents (vanadate, Ca++/calmodulin, and Triton X-100), we find that dynein-like ATPases vary by two orders of magnitude in their sensitivities to inhibition by vanadate, and little or no stimulation by either Ca++/calmodulin or Triton X-100 is seen. Our results suggest that inhibition by EHNA is a universal and specific property of dynein-like ATPases, which ultimately should prove useful in the quantitative purification and characterization of cytoplasmic dynein-like ATPase (s).
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050106
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 38
    Digitale Medien
    Digitale Medien
    Ionic control of locomotion and shape of epithelial cells: I. Role of calcium influx (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 123-136 
    Details
    ISSN: 0886-1544
    Schlagwort(e): locomotion and shape control ; epithelial cells ; calcium ; reflection-interference contrast-microscopy ; cinematography ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The role of calcium in the induction of locomotion, control of direction of locomotion, and modulation of shape of epithelial cells derived from Xenopus laevis tadpole epidermis is investigated. Local influx of calcium is achieved by electrophoretic release of small amounts of calcium from a micropipette (tip diameter 0.1-0.5 μUm) closely apposed to the cell body or lamella. The cells are made permeable for calcium by calcium ionophore A23187, and they are kept in Ca++-free, Mg++-rich EGTA Ringer. Another method used to induce Ca++ influx is local application of A23187 while cells move in normal culture medium.Influx of Ca++ into the lamella induces a localised increase in thickness and enlargement of the lamella. Stationary cells become active and show movement in the direction of the Ca++ gradient. Fried-egg-shaped cells tend to acquire a semicircular shape and start moving. Moving cells change the direction of their locomotion, following the direction of Ca++ release. Influx of Ca++ in the cell body region induces its contraction concomitant with an increase in lamellar area.These observations suggest the presence of two different Ca++-sensitive components: an actomyosin meshwork in the cell body and an actin gel in the lamella. Influx of Ca++ induces contraction of actomyosin and solation of actin gel. Interaction of these two systems would explain modulation of shape and generation of locomotion in epithelial cells.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050205
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 39
    Digitale Medien
    Digitale Medien
    Bending patterns of Chlamydomonas flagella: III. A radial spoke head deficient mutant and a central pair deficient mutant (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 195-208 
    Details
    ISSN: 0886-1544
    Schlagwort(e): central pair ; radial spoke ; flagella ; mutant ; Chlamydomonas ; suppressor ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Flash photomicrography at frequencies up to 300 Hz and computer-assisted image analysis have been used to obtain parameters describing the flagellar bending patterns of mutants of Chlamydomonas reinhardtii. All strains contained the uni1 mutation, to facilitate photography. The radial spoke head deficient mutant pf17, and the central pair deficient mutant, pf15, in combination with suppressor mutations that restore motility without restoring the ultrastructural or biochemical deficiencies, both generate forward mode bending patterns with increased shear amplitude and decreased asymmetry relative to the “wild-type” uni1 flagella described previously. In the reverse beating mode, the suppressed pf17 mutants generate reverse bending patterns with large shear amplitudes. Reverse beating of the suppressed pf15 mutants is rare. There is a reciprocal relationship between increased shear amplitude and decreased beat frequency, so that the velocity of sliding between flagellar microtubules is not increased by an increase in shear amplitude. The suppressor mutations alone cause decreased frequency and sliding velocity in both forward and reverse mode beating, with little change in shear amplitude or symmetry.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050303
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 40
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050401
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 41
    Digitale Medien
    Digitale Medien
    A versatile and quantitative computer-assisted photoelectronic technique used for the analysis of ciliary beat cycles (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 267-292 
    Details
    ISSN: 0886-1544
    Schlagwort(e): mammalian cilia ; respiratory tract ; mucociliary clearance ; laterofrontal cirri ; Mytilus edulis ; beat cycle ; computer analysis ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The beat cycles of rabbit tracheal cilia in culture and Mytilus laterofrontal cirri were recorded using a phototransistor, transillumination, video, and phase-contrast microscopy. The photoelectronic signal and video image of the ciliary activity were simultaneously recorded as a composite image. The photoelectronic signal was converted into a digital signal by a data acquisition system for further computer processing.By the selection of a small detector area and accurate detector alignment, a simple, repetitive photoelectronic signal representing ciliary activity was obtained. This signal records the ciliary beat frequency and demonstrates the triphasic nature of the beat cycle. The photoelectronic signal can be precisely correlated with the ciliary activity by analysis of the composite video recordings to provide the duration of the effective, recovery, and rest phases of the beat cycle. The videophotoelectronic signal correlations were verified by high-speed cinematography. High-speed films of ciliary activity were digitized, and the image density of selected pixels was analyzed by computer with respect to time and ciliary motion.These studies indicate that duration of the phages of the beat cycle are differentially reduced with increased beat frequency; the effective phase duration was quickly reduced to a minimum. This was followed by the reduction of the duration of the recovery phase to a minimum. The rest phase continues to be reduced without reaching a minimum, over the range of beat frequencies observed. These results suggest that ciliary beat frequency may be regulated either by modifying the rates of dynein-microtubule interactions or the rate of transition from one beat phase to the next.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050402
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 42
    Digitale Medien
    Digitale Medien
    Actin assembly and filament cross-linking in the presence of TW 260/240, the tissue-specific spectrin of the chicken intestinal brush border (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 311-322 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Spectrin ; TW 260/240 ; chicken intestinal brush border ; actin assembly ; actin filament cross-linking ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: TW 260/240 is a tissue-specific spectrin found in the terminal web region of the chicken intestinal bruish border. We have examined the effects of TW 260/240 on assembly rates and critical concentrations (Co's) for monomer addition at the barbed and pointed ends of the actin filament. For these studies, acrosomal processes (AP) from Limulus sperm were used as nuclei for actin assembly. Under conditions which favor the interaction of TW 260/240 for actin (20-75 mM KCl, 2 mM Mg++) no effect on either elongation rates or Co's at either end of the actin filament was observed in the presence of this spectrinlike protein. The Limulus AP nucleation assay also allowed visualization of the kinetics of filament binding and cross-linking by TW 260/240. Ultrastructural analysis of TW 260/240 binding to actin filaments at their growing ends indicates that TW 260/240 tetramers bind laterally to the filament. Finally, evidence is presented that indicates that filaments cross-linked by TW 260/240 are stabilized against shear-dependent breakage.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050404
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 43
    Digitale Medien
    Digitale Medien
    Anouncement (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 351-354 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050407
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 44
    Digitale Medien
    Digitale Medien
    Bending patterns of Chlamydomonas flagella: II. Calcium effects on reactivated Chlamydomonas flagella (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 53-60 
    Details
    ISSN: 0886-1544
    Schlagwort(e): calcium ; Chlamydomonas ; flagella ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Ca2+ has profound effects on the movement of cilia and eukaryotic flagella, including those of Chlamydomonas. Two clear changes seen in Chlamydomonas flagella with changes in Ca2+ are beat frequency and symmetry. Photographic and computer assisted analysis of flagellar bending patterns on a uniflagellate mutant of Chlamydomonas have been used to examine details of the effects of Ca2+ on the movement of ATP-reactivated, demembranated flagella. In addition to the forward mode bending pattern seen at low Ca2+ concentrations (10-9 M), which has a frequency of about 50 Hz and the reverse mode bending pattern seen at high Ca2+ concentrations (10-4 M) with a frequency around 70 Hz, we carefully examined bending patterns in the intermediate Ca2+ concentration range of 1-6.5 × 10-6 M. In this intermediate range, the bending patterns have significantly reduced asymmetry and slightly increased frequency, compared to the motility observed at low Ca2+ concentrations. These observations indicate that changes in these two parameters of motion do not occur in parallel and suggest that the effects of Ca2+ may be a multicomponent process. Physiologically, these changes in the beat pattern at intermediate Ca2+ may signal either (1) the beginning stages of transition to the symmetrical, high-frequency beating seen at high Ca2+, or (2) a more normal forward mode motility for the trans flagellum as suggested by Kamiya and Witman [1984]. No large amplitude bending patterns associated with transitions between forward and reverse mode beating in intact cells were seen at the intermediate Ca2+ concentrations.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050105
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 45
    Digitale Medien
    Digitale Medien
    Flow birefringence of microtubules and its relation to birefringence measurements in cells (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 31-51 
    Details
    ISSN: 0886-1544
    Schlagwort(e): microtubules ; birefringence ; flow birefringence ; tubulin ; polarization microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Understanding the molecular basis of mitotic movements in living cells will require correlative experiments on intact cells, cell models, purified tubulin, and perhaps other biopolymers. Birefringence is one assay that is useful in all of these experimental situations. Heretofore, studies of birefringence changes during mitosis have lacked a quantitiative basis for interpretation in terms of microtubule number and packing density. One of the aims of this work was to establish that relationship.Purified calf brain tubulin was polymerized to equilibrium and oriented in the hydrodynamic field of a microcapillary flow birefringence apparatus. The relationship between birefringence and microtubule packing density was determined by a combination of optical, electron microscopic, and biochemical methods. The data correlate surprisingly well with those obtained by others from in vitro measurements on isolated mitotic spindles. Using the flow birefringence data, the sensitivity of polarizing microscopes for detecting microtubules was examined and found to depend on microtubule packing density, object thickness, and instrumental factors that limit both the detection and measurement of weakly birefringent objects. Because of the dependence of measurement sensitivity on object thickness, a method of measuring the thickness of microtubule bundles using the dispersion of birefringence was developed. This method is capable of measuring thickness to within two or three Airy diffraction units and does not require any assumptions regarding object symmetry.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050104
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 46
    Digitale Medien
    Digitale Medien
    Fundamental problems of movement of cilia, eukaryotic flagella, and related systems: A seminar held under the U.S. Japan cooperative science program (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 137-173 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050206
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 47
    Digitale Medien
    Digitale Medien
    Study of the properties of MgATP2--induced stationary bends in demembranated sea urchin sperm (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 209-224 
    Details
    ISSN: 0886-1544
    Schlagwort(e): flagellar dynein ; cyclic nucleotides ; sperm activation ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Methods of demembranation and reactivation of Lytechinus pictus sperm were developed that result in non-motile sperm which take on a stable bend of about 3.5 radians at the proximal end of the cell. The middle and distal portion of the flagellum is relatively straight or slightly bent in the same direction forming a somewhat “C” shaped sperm cell. In these studies, we refer to this characteristic shape as the quiescent form, and as opposed to “rigor wave” sperm, the quiescent form is induced and maintained by a relatively high concentration of MgATP2- (〉 0.2 mM). Other conditions important to the production and maintenance of the quiescent form in demembranated sperm include: starting with concentrated, undiluted sperm, maintaining low Ca++ in the demembranation buffer, using a minimum of 0.2 mM MgATP2- and pH of 7.9-8.1 in the reactivation buffer. Deviation from some of these conditions results in a dramatic increase in motile, asymmetrically beating sperm. Addition of 0.4 mM CaCl2 to the reactivation buffer increased the proximal bend angle to 5 radians. The induction and maintenance of the stationary bend is mediated by dynein activity: “rigor wave” sperm were transformed to the quiescent form upon 0.2 mM ATP addition; micromolar vanadate abolished the quiescent form by “relaxation” of the proximal bend; and the vanadate relaxed sperm were restored to quiescent form by catechol. Importantly, 20 μM cAMP activated motility of the otherwise quiescent-form sperm. Quiescent-form, demembranated sperm were also activated by mild trypsin digestion. These and other data suggest that the quiescent-form sperm are trapped at the end of the principal bend, and these data are consistent with the proposal that the single stationary bend results from asymmetry of active microtubule sliding [Gibbons and Gibbons, (1980): J. Cell Biol. 84:13-27].
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050304
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 48
    Digitale Medien
    Digitale Medien
    Tension in the culture dish: Microfilament organization and migratory behavior of quail neural crest cells (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 225-237 
    Details
    ISSN: 0886-1544
    Schlagwort(e): neural crest ; migratory behavior ; microfilaments ; stress fibers ; tractional force ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: We have investigated one aspect of the migratory behavior of quail neural crest (NC) cells by comparing the organization of microfilament bundles and the ability to distort migratory substrata by NC, somite, and notochord cells in vitro. In contrast to the numerous cytoplasmic stress fibers in somite-derived fibroblasts and notochord cells revealed by rhodamine-phalloidin staining and thin-section electron microscopy, microfilaments in NC cells are restricted to the cell cortex. To test the relative degrees of tension generated by these cell types on the underlying substratum, cells were cultured in collagen gels and on distortable silicone rubber sheets. Explanted somites and notochords produced dramatic radial alignment of 750 μg/ml collagen gels, whereas neural crest cells only aligned gels of lower concentrations. Fibroblasts did not migrate individually from explanted somites and notochords into 250 μg/ml collagen gels as readily as into higher concentration collagen lattices. In contrast, neural crest cells migrated into matrices of low concentration as well as into higher concentration collagen gels. Neural crest cells and their pigmented derivatives did not distort silicone rubber sheets, whereas somite and notochord-derived fibroblasts wrinkle this substratum after 4 days in culture. Thus, the differences in organization of the actin cytoskeleton reflect the tractional force exerted by these cells on their substratum. We hypothesize that the migratory behavior of NC cells in vivo may be related to their ability to translocate through embryonic extracellular matrices while generating relatively weak adhesions with the substratum, whereas the stronger forces generated by other embryonic cell types upon the delicate extracellular matrix may restrict their migration and may be associated with other morphogenetic events.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050305
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 49
    Digitale Medien
    Digitale Medien
    Proteins closely similar to flagellar tektins are detected in cilia but not in cytoplasmic microtubules (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 239-249 
    Details
    ISSN: 0886-1544
    Schlagwort(e): tektins ; microtubules ; flagella ; cilia ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Affinity-purified antibodies against Strongylocentrotus purpuratus sperm flagellar tektin polypeptides have been tested for cross-reactivity with microtubules isolated from various sources, using indirect immunofluorescent staining and antibody binding to nitrocellulose replicas of SDS polyacrylamide gels. The antitektins reacted with sperm tail axonemes from four genera of sea urchins and with cilia from sea urchin embryos. Antibody binding was observed only if the specimens were prefixed by methods that would not preserve them well at an ultrastructural level. However, even after such fixation regimes, no antibody binding was detected to cytoplasmic microtubule arrays in the same embryos, to mitotic spindles isolated from sea urchin or to gill cilia from a mollusc. We conclude that, if tektins are present in sea urchin egg cytoplasmic microtubules, they are sufficiently different from the sperm tektins to have no common strongly antigenic determinants.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050306
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 50
    Digitale Medien
    Digitale Medien
    Localization of actin in Chlamydomonas using antiactin and NBD-phallacidin (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 415-430 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Actin ; immunofluorescence ; NBD-phallacidin ; Chlamydomonas ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: We have localized actin in gametes of Chlamydomonas reinhardi by two approaches: (1) indirect immunofluorescence with an affinity-purified antibody and (2) staining with NBD-phallacidin, a fluorescent reagent that binds only to F-actin [Barak et al, 1980, Proc Natl Acad Sci, 77:980-984]. Staining of either mating type “plus” (mt+) or “minus” (mt-) gametes with antiactin antibody resulted in similar fluorescent images: most of the actin was located peripherally along the lateral and posterior aspects of the cells. There was diffuse staining centrally, but the flagella did not stain. No brightly stained spot was observed near the mt+ mating structure, the site where the fertilization tubule elongates with concomitant polymerization of actin [Detmers et al, 1983, J Cell Biol, 97:522-532]. Gametes stained prior to mating with NBD-phallacidin showed no fluorescence above background, indicating that there were no concentrations of F-actin in these cells. This suggested that the cytoplasmic staining observed with antiactin represented primarily a nonfilamentous form of the protein. In mating gametes staining with NBD-phallacidin was detected only in the fertilization tubule, indicating that this was the only dense accumulation of filamentous actin within the cells. Mating gametes stained with antiactin antibody exhibited cytoplasmic fluorescence that was slightly more punctate than prior to mating, and the fertilization tubule was brightly stained. Our observations suggest that the site-specific polymerization of actin within the fertilization tubule occurs in the absence of a concentrated pool of actin subjacent to the mating structure.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050505
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 51
    Digitale Medien
    Digitale Medien
    Non-actin filaments and cell contraction in Kofoidinum and other Dinoflagellates (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 1-15 
    Details
    ISSN: 0886-1544
    Schlagwort(e): contractile non-actin filaments ; dinoflagellates ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The motility and fine structure of the marine planktonic dinoflagellate Kofoidinium and members of other related genera have been investigated. Several types of shape change were found to occur: slow morphogenetic changes (which also occurred as restitution movements in response to injury), movements associated with the ingestion of food and the evacuation of wastes, and more rapid movements concerned with the capture of prey. All these movements seemed to be brought about by the contraction of refractile tracts within the cytoplasm, which were found to contain 2.3-nm filaments, some with a complex striated appearance. This and other evidence suggests that these filaments, which have counterparts in many other protists, are not actin filaments.
    Zusätzliches Material: 22 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050102
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 52
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985) 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050201
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 53
    Digitale Medien
    Digitale Medien
    Video microscopy of fast axonal transport in extruded axoplasm: A new model for study of molecular mechanisms (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 81-101 
    Details
    ISSN: 0886-1544
    Schlagwort(e): fast axonal transport ; isolated axoplasm ; video microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: The development of AVEC-DIC microscopy and the application of this method to the study of fast axonal transport in isolated axoplasm extruded from the giant axon of the squid Loligo pealei provides a new paradigm for analyzing the intracellular transport of membranous organelles. The size of the axon, the number of transported particles, and the absence of permeability barriers like the plasma membrane in this preparation permit many experiments that are difficult or impossible to perform using other model systems. The use and features of this preparation are described in detail and a number of properties are evaluated for the first time. The process of extrusion is characterized. Particle movement is evaluated both in the interior of extruded axoplasm and along individual fibrils that extend from the periphery of perfused axoplasm. The role of divalent cations, particularly Ca2+, and the effects of elevated Ca2+ on axoplasmic organization and transport are analyzed. A series of pharmacological agents and polypeptides that alter cytoskeletal organization are used to examine the role of microfilaments and microtubules in fast transport. Finally, the effects of depleting ATP and of adding ATP analogues are discussed. The extruded axoplasm preparation is shown to be an invaluable model system for biochemical and pharmacological analyses of the molecular mechanisms of intracellular transport.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050203
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 54
    Digitale Medien
    Digitale Medien
    Analysis of the morphology and function of primary cilia in connective tissues:A cellular cybernetic probe? (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 175-193 
    Details
    ISSN: 0886-1544
    Schlagwort(e): primary cilia ; connective tissues ; secretory organelles ; extracellular matrix ; cybernetic probe ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: More than 300 primary cilia have been identified electronmicroscopically in a variety of embryonic and mature connective tissue cells. To further define the enigmatic function of these cilia, we examined the interrelationships between the basal apparatus and cytoplasmic organelles and the ciliary shaft and the extracellular matrix. The basal diplosome was consistently associated with the secretory organelles including the maturing face of the Golgi complex, Golgi vacuoles and vesicles, the microtubular network, the plasma membrane, and coated pits and vesicles. Small vesicles and amorphous granules were also observed within the ciliary lumen and adjacent to the ciliary membrane. Microtubule-membrane bridges linked axonemal tubules to the ciliary membrane. The position, projection, and orientation of the axoneme were influenced by the structural organisation and mechanical properties of the matrix and frequently caused angulation of the ciliary shaft relative to the basal body. Located midway between the secretory apparatus and the extracellular matrix, primary cilia would appear ideally situated to mediate the necessry interaction between the cell and its surrounding environment prerequisite to the formation and maintenance of a functionally effective matrix. We propose that primary cilia in connective tissue cells could act as multifunctional, cellular cybernetic probes, receiving, transducing, and conducting a variety of extrinsic stimuli to the intracellular organelles responsible for effecting the appropriate homeostatic feedback response to changes in the extracellular microenvironment.
    Zusätzliches Material: 17 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050302
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 55
    Digitale Medien
    Digitale Medien
    Erratum (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 265-265 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050308
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 56
    Digitale Medien
    Digitale Medien
    Tetrahymena cell model exhibiting Ca-dependent behavior (1985)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 323-331 
    Details
    ISSN: 0886-1544
    Schlagwort(e): Tetrahymena ; cell model ; ATP concentration ; Ca sensitivity ; backward swimming ; Life and Medical Sciences ; Cell & Developmental Biology
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie , Medizin
    Notizen: Using Tetrahymena pyriformis, strain w, and Tetrahymena thermophila, B-1868, we prepared cell models that showed ciliary reversal with change in Ca-ion concentration, as was also noted for the Paramecium cell model. No differences could be found between these two strains in the reactivation state, and their response to environmental conditions was essentially the same. The reactivation rate was 90% or more. Swimming velocity of the cell model was found to be 200 ± 49 μm/sec at 25.0°C ± 0.5°C, while the velocity for the living cells was 527 ± 101 μm/sec. Swimming velocity with change in environmental conditions, such as pH, Mg-ATP, and Ca-ion concentrations, was studied. Compared to the cell model of Paramecium, the Tetrahymena cell model had higher sensitivity toward Ca-ion in the reactivation medium. The effects of chlorpromazine, and inhibitor of calmodulin, on the swimming behavior of the cell models were studied.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cm.970050405
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 57
    Digitale Medien
    Digitale Medien
    Thermometrische Untersuchungen zur Bestimmung des effektiven Threshold-Wertes ΔKth (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 143-150 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Thermometric Investigations for the Determination of the Effective Threshold ΔKthIn metallic materials crack propagation starts with local plastic deformation above the effective threshold for fatigue. Elastic deformation and beginning plastic deformation at a crack tip can be determined thermometrically due to the thermoelastic effect and dissipation of energy. Thus crack opening loads can be defined, and the effective threshold for fatigue may be determined as a constant of material.
    Notizen: In metallischen Werkstoffen erfolgt die Ausbreitung eines Ermüdungsrisses mit örtlicher plastischer Verformung oberhalb des effektiven Schwellenwertes der zyklischen Spannungsintensität. Elastische Verformung sowie der Beginn plastischer Verformung an der Spitze eines Risses können unter Ausnutzung des thermoelastischen Effekts sowie der Dissipation der Verformungsarbeit thermometrisch erfaßt werden. Es gelingt auf diese Weise, die Rißöffnungslast und damit den effektiven Schwellenwert der zyklischen Spannungsintensität als Werkstoffkonstante zu bestimmen.
    Zusätzliches Material: 15 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160413
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 58
    Digitale Medien
    Digitale Medien
    Die Wechselfestigkeit dickwandiger Rohre und Hohlzylinder unter pulsierendem Innendruck Herrn Professor Dr. Karl August Wetjen zum 60. Geburtstag gewidmetHerrn Professor Dr. Karl August Wetjen zum 60. Geburtstag gewidmet. (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 165-173 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: The Fatigue Strength of Thick-Walled Cylinders and Tubes under Pulsating PressureThe results of many investigations into the fatigue strength of thick walled cylinders and tubes have been published. The present study sets out to check if ASME CODE Sect. VIII, Div. 2 and AD-Merkblatt S2 correspond to these fatigue test results and what alterations may still be needed.In the course of the systematic collection of experimental data, almost 60 publications were found, in which approximately 960 individual test results are described.The comparison shows, that the calculation according to AD-Merkblatt S2 corresponds very well to the test results, a minor modification may increase the accuracy.The calculation according to ASME CODE is less exact.
    Notizen: Es sind bereits viele Ergebnisse von Druckpulsationsversuchen an dickwandigen Zylindern veröffentlicht worden, es fehlte jedoch ein Vergleich der Versuchsergebnisse mit den gültigen Berechnungsvorschriften.Die vorliegende Studie zeigt, daß die Berechnung nach AD-Merkblatt S2 verhältnismäßig gut mit den Versuchsergebnissen übereinstimmt. Durch eine geringfügige Änderung könnte die Genauigkeit noch wesentlich erhöht werden.Im Gegensatz dazu ist die Berechnung nach ASME CODE Sekt. VIII, Div. 2 nicht so genau.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160505
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 59
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985) 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160101
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 60
    Digitale Medien
    Digitale Medien
    Haftfestigkeit von Metallschichten auf Stählen bei statischer und wechselnder BeanspruchungMitteilung aus dem Forschungsinstitut Werkstofftechnik Metalle der AEG-Telefunken Anlagentechnik AG, Frankfurt/M (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 1-12 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Influences of Static and Dynamic Load on the Adhesive Strength of Thermally Sprayed Metal Coatings on SteelsIt were the aims of this work to produce metal-sprayed specimens and workpieces with high resistance to static and dynamic load, to prove these properties by appropriate measurements and to give advices for practical application.For this purpose, two different substrate materials were metal-coated with five materials by use of three spraying techniques. As a result of the investigations, it can be summarized that specimens, which were shot-peened prior to spray-coating reached the same fatigue limit as only shot-peened specimens, independent on the spraying technique applied.
    Notizen: Die Ziele der Arbeit bestanden in der Herstellung von metallgespritzten Proben und Bauteilen mit möglichst hoher statischer und dynamischer Beanspruchbarkeit, im Nachweis dieser Eigenschaften durch entsprechende Messungen und in Empfehlungen für den praktischen Einsatz. Zu diesem Zweck wurden zwei Grundwerkstoffe mit fünf Spritzwerkstoffen nach drei Spritzverfahren beschichtet und anschließend untersucht. Aus den Ergebnissen geht hervor, daß kugelgestrahlte und anschließend metallgespritzte Proben unabhängig von Spritzwerkstoff und -verfahren Dauerfestigkeiten erreichen, die denen des jeweiligen kugelgestrahlten ungespritzten Grundwerkstoffs nahekommen.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160104
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 61
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A10 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160202
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 62
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A2 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160102
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 63
    Digitale Medien
    Digitale Medien
    Einfluß von Eigenspannungen auf Die Werkstoffanstrengung in wälzbeanspruchten Bauteilen (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 19-24 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Influence of Internal Stresses on the Stressing of Material in Components Subjected to Rolling-Contact LoadsThe stressing of a material in concentrated contacts can be calculated using f. e. the equivalent stress hypothesis by Huber, von Mises, Hencky (distortion energy hypothesis). The stress level can be directly related to the local yield properties of the material. For the calculation of the equivalent stress the influence of friction and internal stresses in the material have to be taken into account. The local stress level in the half space strongly depends on friction and internal stresses. It will be demonstrated, that it is necessary to have a look at a greater part of the full half space to find the maximum stress level.
    Notizen: Die Beanspruchung eines Werkstoffes in Hertz'schen Kontakten läßt sich z. B. mit der Gestaltänderungsenergie-Hypothese (Huber, von Mises, Hencky) als Vergleichsspannung berechnen. Diese Vergleichsspannung kann dann zu den lokalen Fließeigenschaften des Werkstoffes direkt in Beziehung gesetzt werden. Bei der Berechnung der Werkstoffanstrengung muß jedoch der Einfluß der Reibung und der Eigenspannungen im Werkstoff berücksichtigt werden. Es wird gezeigt, daß es unbedingt erforderlich ist, einen größeren Bereich des Halbraumes unter dem Kontakt zu betrachten, um das Maximum der Werkstoffanstrengung zu erfassen.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160106
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 64
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985) 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160201
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 65
    Digitale Medien
    Digitale Medien
    Beiträge zur Untersuchung der Korrosion An Modellwerkzeugstählen für kunststoffverarbeitende MaschinenMitteilung aus dem Deutschen Kunststoff-Institut, Darmstadt (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 31-38 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Contributions to the Study of the Corrosion on Models of the Alloy Steels for Plastic Processing MachinesThe corrosion on the alloy steels 9 S 20 K and 165 X CrMoV 12 during processing of glassfiber reinforced and non-reinforced plastic melts of styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-copolymer, polypropylene, styrene-acrylonitrile-butadiene-copolymer and polycarbonate were tested. The volatile compounds evolved during injection molding were condensed and analysed by means of gas-chromatography (GC), gas-chromatography-mass-spectroscopy (GC-MS) and nuclear-magnetic-resonance (NMR). They mainly consisted of hydrocarbons and monomers form the degraded plastics. Because of the absence of water, electrochemical corrosion need not be considered. A mechanism on the basis of chemical reactions between the polymer melt and the steel surface was considered to cause corrosion. By means of scanning electron microscopy differences in the surfaces of the steels corroded with different polymer melts could be observed. Analysis of the surfaces by secundary-ion-mass-spectroscopy (SIMS) resulted in changes being specific for the polymers. On all the corroded steel surfaces high spectral carbon intensities were detected compared with non corroded ones, as well as higher intensities for the steel compounds like chromium, manganese and vanadium. Chemical reactions of these compounds with the polymer melt were considered to cause changes in the lattices of the steel resulting in a change of the properties.
    Notizen: Der Verschleiß an den Modellwerkzeugstählen 9 S 20 K und 165 X CrMoV 12 bei der Thermoplastverarbeitung wurde mit den Schmelzen von glasfaserverstärkten und unverstärkten Styrol-Acryl-nitril-Copolymeren (SAN), Polypropylen, Acrylnitril-Butadien-Styrol-Pfropfpolymeren (ABS) und Polycarbonat untersucht. Die beim Spritzgißen freigesetzten flüchtigen Substanzen wurden isoliert und mit Gaschromatographie (GC), Gaschromatographie-Massenspektrometrie (GC-MS) und Kernresonanzspektroskopie (NMR) charkterisiert; es handelt sich vorwiegend um Kohlenwasserstoffe und Monomere der Kunststoffrohstoffe. Aufgrund der nachweislichen Abwesenheit von Wasser kommt eine elektrochemische Korrosion nicht in Betracht, weshalb chemische Reaktionen vorwiegend zwischen Kunststoffschmelze und Stahloberfläche als Korrosionsursache angesehen werden müssen. Mit Hilfe von rasterelektronenmikroskopischen (REM) Untersuchungen wurden Unterschiede zwischen den mit verschiedenen Schmelzen korrodierten Stählen festgestellt. Untersuchungen der Metalloberflächen mit Sekundärionenmassenspektrometrie (SIMS) ergaben kunststoffspezifische Veränderungen. Auf allen korrodierten Stahloberflächen traten im Vergleich zu den unkorrodierten sowohl hohe spektrale Kohlenstoffintensitäten als auch verstärkte Signale von Verbindungen der Stahlbestandteile Chrom, Mangan und Vanadium auf. Die Reaktion dieser Bestandteile mit der Kunststoffschmelze kann als Ursache für Gitteränderungen im Stahl und die damit verbundenen Eigenschaftsänderungen betrachtet werden.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160108
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 66
    Digitale Medien
    Digitale Medien
    Numerische Auswertung von Zugversuchen an CuZn 40 mit Ausgleichskurven (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 70-73 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Numeric Evaluation of Tensile Tests of Brass CuZn 40 by Fitted CurvesTwo measured stress strain curves of brass CuZn 40 are approximated by fitted curves and with these dates are calculated: Young's modules, tangent modules, work capacity and proof stresses. The accordance is jugded by standard deviation. The Langevin-Function is the most favourable.
    Notizen: Es werden gemessene Spannung-Dehnung-Kurven von Messing CuZn 40 durch zwei Ausgleichsfunktionen angenähert und daraus dann E- und Tangenten-Modul, Arbeitsvermögen und Dehngrenzen errechnet. Die Übereinstimmung wird mit der Standardabweichung beurteilt. Am besten eignet sich die Langevin-Funktion.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160209
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 67
    Digitale Medien
    Digitale Medien
    Umformtechnik. Von K. Lange, Universität Stuttgart. Handbuch für Industrie und Wissenschaft. 2., völlig neubearbeitete Auflage (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 74-74 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160213
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 68
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A20 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160302
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 69
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A17 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160215
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 70
    Digitale Medien
    Digitale Medien
    Microstructural aspects of Thermal Stress Resistance of high-strength engineering ceramics. Part III: Improvement of thermal stress resistance of high-strength engineering ceramics (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 81-88 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Temperaturwechselverhalten hochfester ingenieurkeramischer Werkstoffe - Kenndaten, Gefügeeinfluß, Verbesserung - Teil IIITeil III: Verbesserung des Temperaturwechselverhaltens hochfester ingenieurkeramischer WerkstoffeIn den Teilen I und II dieser Arbeit wurden folgende Schwerpunkte behandelt: Grundlegende Kriterien zur Verbesserung des Thermoschockverhaltens ingenieurkeramischer Werkstoffe; Kenndaten des Temperaturwechselverhaltens hochfester ingenieurkeramischer Werkstoffe (Thermoschock und zyklische thermische Beanspruchung); und der Einfluß des Gefüges auf das Thermoschockverhalten, wobei dieser Punkt den Einfluß verschiedener Gefügeparameter auf die mechanischen und thermischen Eigenschaften, die das Thermoschockverhalten im wesentlichen bestimmen, einschließt. Im Teil III dieser Arbeit werden die Möglichkeiten zur Verbesserung des Thermoschockverhaltens durch Gefügeoptimierung diskutiert. Die einzelnen Verfahrensschritte der Eigenschaftsverbesserung werden aufgezeigt. Weiterhin wird die Verbesserung des Thermoschockverhaltens durch die Entwicklung von Verbundwerkstoffen dargestellt. Diese Entwicklungsarbeiten basieren auf Überlegungen, wie man einige für das Thermoschockverhalten wichtige Eigenschaften durch Entwicklung neuer Werkstoffe verbessern kann. Hier werden Ergebnisse früherer Arbeiten und neuerer Entwicklungen zusammengefaßt.
    Notizen: The main objectives of parts I and II of this paper were: basic criteria for the improvement of thermal shock resistance of engineering ceramics; data about the thermal stress resistance of high-strength engineering ceramics (thermal shock and thermal cycling); and the influence of microstructure on thermal shock resistance to fracture initiation, including the influence of various microstructural variables on the mechanical and thermal properties which mainly control the thermal shock resistance to fracture initiation. In part III of this paper the possibility to improve the thermal shock resistance to fracture initiation by microstructural optimization is demonstrated. This includes a description of the different steps of the improving procedure. Moreover, the improvement of thermal stress resistance by developing advanced composite materials based on theoretical considerations of improving some important properties by microstructural design is outlined. Here the results of previous investigations and of recent developments are summarized.
    Zusätzliches Material: 25 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160307
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 71
    Digitale Medien
    Digitale Medien
    Haftfestigkeitsbestimmung an Keramik-Metall-Verbindungen mit Hilfe von Schichtverbundbiegeproben - Teil 1 (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 75-80 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Bond Strength Determination of Metal-to-Ceramic Joints by a Bend Test Method-Part 1The bond strength of metal-to-ceramic joints can be described by fracture mechanics parameters. Sandwich-like layered bend test specimens are notched at a metal-ceramic interface which is located in the middle of the test bar and perpendicular to its length dimensions. During bend testing of the joints generally a linear relationship between load and deflection is observed. From the fracture load, the geometry of the specimens, and by means of so-called correction functions the fracture energy and the fracture resistance of the interface are determined. The correction functions depend on the notch depth, the thicknesses of layers, the distance between notch and interface, and the elastic properties of the bonded materials, and can be calculated by use of the finite element method. Correction functions of material joints are compared with the correction functions for homogeneous isotropic materials and bimaterials. An approximation method for the determination of correction functions is presented. Examples of bond strength measurements demonstrate the necessity of correction functions.
    Notizen: Die Haftfestigkeit von Keramik-Metall-Verbindungen läßt sich mit Hilfe von bruchmechanischen Kenngrößen beschreiben. Zu ihrer Bestimmung bieten sich Schichtverbundbiegeproben mit einem Kerb im Materialübergangsbereich an, deren quasi-sprödes Bruchverhalten die Anwendung der linear-elastischen bruchmechanischen Prüftechnik ermöglicht. Die Auswertung des Biegeversuchs liefert als Haftfestigkeitsmaß Werte der kritischen Energiefreisetzungsrate und des kritischen Spannungsintensitätsfaktors, die Grenzflächenbruchenergie GC und Grenzflächenbruchwiderstand KC genannt werden. Die zur Ermittlung der Haftfestigkeitsparameter erforderlichen Korrekturfunktionen hängen von geometrischen Faktoren wie der Kerbtiefe, der Schichtdicke und dem Abstand des Kerbs zur Grenzfläche ab und werden von den elastischen Eigenschaften der am Verbund beteiligten Werkstoffen bestimmt. Die Abhängigkeit der Korrekturfunktionen wird allgemein dargestellt. Für einige Materialkombinationen wird sie durch Nachgiebigkeitsmessungen und Berechnungen mit Hilfe der Methode der finiten Elemente explizit bestimmt. Es wird ferner eine Näherungsmethode zur Ermittlung der Korrekturfunktion für beliebige Materialpaarungen vorgestellt. Haftfestigkeitsmessungen an Glas-Epoxid-Modell-Verbindungen und festkörperverschweißten Keramik-Metall-Verbindungen bestätigen die Notwendigkeit der Korrekturfunktionen zur Bestimmung der Grenzflächenbruchenergie und des Grenzflächenbruchwiderstandes.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160306
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 72
    Digitale Medien
    Digitale Medien
    Extrusion. Scientific and Technical Developments. Edited by G. Lang, A. F. Castle, M. Bauser, G. Scharf. Proceedings of a symposiums organised by Deutsche Gesellschaft für Metallkunde in association with The Metals Society, London, 1982, under the direction of Günther Scharf. 296 pp. numerous diagrams, illustrations and tables. All papers published in English. 1983. Bound, 16 × 23,5 cm. European Countries DM 126,-, Overseas $ 63,-. ISBN 3-88355-066-3 (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A27 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160313
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 73
    Digitale Medien
    Digitale Medien
    Keramische Hochleistungsbauteile für den Motoren- und Triebwerksbau (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A30 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160402
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 74
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A37 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160406
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 75
    Digitale Medien
    Digitale Medien
    Mechanical properties of In-Situ Composites (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 116-121 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Notizen: In this paper, author's results of several years of research work on the mechanical properties of directionally solidified (In-Situ) composites are reviewed. Alloy systems investigated were the fibrous Al-Ni, Fe-MnS and the cobalt base superalloy Co-Cr-C and the lamellar Al-Cu and Co-W. The mechanical behavior of the above systems were studied under both static and dynamic loadings. Static loading involved tension, compression and 3-point bending and the dynamic loading involved rotating bending fatigue, fatigue crack propagation and strain controlled fatigue.It was found that the tensile fracture stress and toughness and the ultimate compressive stress were generally enhanced by increasing growth rate and/or temperature gradient. However, at very high growth rates, the properties were found to decrease due to misalignment of the structure. Models were suggested to describe the static behavior of the composites investigated. Good agreement was found between the model predictions and the experimented results which indicate that the static properties are structural sensitive. On the contrary, the fatigue life of the Al-Al3 Ni was insensitive to structural changes caused by varying the growth rate. The fatigue crack propagation response of the Co-Cr-C composites was found to follow the Paris Erdogan relation. Examination of the fracture surface confirmed a brittle mode of fracture with fiber cleavage and matrix shearing to link up fiber breaks.
    Zusätzliches Material: 20 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160409
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 76
    Digitale Medien
    Digitale Medien
    Einfluß einer Oberflächenkaltverfestigung auf die Schwingfestigkeit und das Wechselverformungsverhalten der normalisierten Kohlenstoffstähle Ck 15 und Ck 45 unter Zugdruck-und UmlaufbiegebeanspruchungTeilauszug aus der Dissertation des erstgenannten Verfassers (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 135-143 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Effect of Surface Cold Working on Fatigue Strength and Cyclic Stress-Strain Behaviour of Normalized Plain Carbon Steels Ck 15 and Ck 45 under Compression-Tension and Rotating Bending LoadInvestigations on deep rolled specimens of normalized plain carbon steels showed that surface could working can improve the fatigue strength by about 15% in rotating bending tests and by about 5% in cyclic compression-tension tests. The better endurance properties are mainly caused by a reduced amplitude of plastic strain.From microscopical examinations of Ck 15 surfaces was deduced that crack initiation in deep rolled specimens resembles by far with that in specimens not surface treated.During fatigue tests the dislocation structure produced by deep rolling approached that developing in samples without cold worked surface.
    Notizen: Wechselverformungsmessungen ergaben, daß die Schwingfestigkeitszunahme (etwa 15% bei Umlaufbiege- und etwa 5% bei Zug-Druck-Beanspruchung) festgewalzter Proben primär auf eine reduzierte plastische Dehnung gegenüber nichtverfestigten Proben zurückgeführt werden kann.Mikroskopische Untersuchungen an Ck 15 zeigten, daß die Rißbildung auch bei festgewalzten Proben von der Oberfläche ausgeht und sich nicht prinzipiell von der unverfestigter Proben unterscheidet.Die beim Kaltverfestigen erzeugten Versetzungsstrukturen oberflächennaher Bereiche werden durch das Auftreten plastischer Dehnungen umgelagert und nähern sich während der Wechselbeanspruchung somit den Strukturen nicht festgewalzter Proben.
    Zusätzliches Material: 21 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160412
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 77
    Digitale Medien
    Digitale Medien
    Beitrag zur Vermeidung von chloridinduzierter transkristalliner Spannungsrißkorrosion bei höher legierten Chrom-Nickel-Stählen durch InhibitorenMitteilung aus dem Institut für Werkstoffkunde der TH Darmstadt. Auszug aus der Dissertation des erstgenannten Verfassers, Darmstadt D17, demnächst. (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 173-181 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Avoidance of Chloride Induced Transgranular Stress Corrosion Cracking of Stainless Steels by InhibitorsThe possibility to avoide chloride induced transgranular SCC of stainless steels with higher contents of chromium and nickel with the aid of organic inhibitors is shown. This method is successful as well in boiling aqueous solutions with high chloride concentration (open system) as in closed systems (higher temperature and pressure) with low chloride contents.
    Notizen: Obwohl die Möglichkeit zur Hemmung von Korrosionsvorgängen durch Inhibitoren schon seit langem bekannt ist, wurden bisher kaum Versuche unternommen, die chloridinduzierte Spannungsrißkorrosion von höherlegierten Chrom-Nickel-Stählen durch Anwendung dieser Kenntnisse zu verhindern. In der vorliegenden Arbeit werden Ergebnisse aus Untersuchungen mit Tensiden und handelsüblichen Inhibitoren vorgestellt, die erkennen lassen, daß sowohl in höher chloridhaltigen siedenden wäßrigen Lösungen (offenes System) als auch in geschlossenen Systemen mit geringem Chloridgehalt bei höheren Temperaturen und Drücken eine deutliche Standzeitverlängerung erreichbar ist.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160506
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 78
    Digitale Medien
    Digitale Medien
    Rekristallisation metallischer Werkstoffe. Grundlagen - Analyse - Anwendung. Herausgegeben von G. Gottstein. Lehrinhalt und Vortragstexte eines Fortbildungsseminars der Deutschen Gesellschaft für Metallkunde e.V. unter der Leitung von Prof. Dr. G. Gottstein, durchgeführt am Institut für Allgemeine Metallkunde und Metallphysik der RWTH Aachen. 275 S. Text und zahlreiche Abbildungen, umfangreiches Stichwortverzeichnis, 1984, gebunden, 15 × 21 cm. Europa DM 80,-, Übersee $ 38,-. ISBN 3-88355-062-0 (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 186-186 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160509
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 79
    Digitale Medien
    Digitale Medien
    Druckversuch an Scheiben zur Prüfung der Wasserstoffversprödung von Metallen (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 209-215 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Disc-Pressure-Testing of Hydrogen EmbrittlementAn apparatus for disc-pressure-tests is presented. The bursting pressure with helium and with hydrogen is measured versus the rate of pressure increase. Under hydrogen most metals show a distinct minimum of bursting pressure. Some explanations for this minimum are proposed. The maximum ratio of bursting pressures x = (PHe/HH2)max is taken as an indicator for hydrogen embrittlement.Steel similar to SAE 4137 (34 CrMo 4) is tested in several states (tempered, normalized, cold-rolled), as well as austenitic steel, various other metals (V, Nb, Ta, Mo) and some amorphous metals. The disc-pressure-test is shown to be easy and useful for determining hydrogen embrittlement. Even austenitic steel exhibits some embrittlement (x = 1.5). The strongest embrittlement occurred in amorphous metal Vitrovac 0040 with x = 9.8.
    Notizen: Eine Anlage für Beulversuche wird vorgestellt. Es werden an scheibenförmigen Proben die Berstdrücke unter Helium und unter Wasserstoff ermittelt. Der jeweilige Berstdruck wird als Funktion der Druckanstiegsgeschwindigkeit dargestellt. Dabei erhält man für die meisten Metalle ein deutliches Berstdruckminimum unter Wasserstoff. Seine Entstehung wird diskutiert. Als Maß für die Wasserstoffempfindlichkeit wird das Berstdruckverhältnis x = (PHe/PH2)max angegeben.Untersucht wurde der Werkstoff 34 CrMo 4 im vergüteten sowie normalisierten und kaltverformten Zustand, ferner austenitischer Stahl, NE-Metalle (V, Nb, Ta, Mo) und amorphe Metalle. Die Messungen bestätigen, daß der Beultest besonders einfach und zweckmäßig zum Nachweis der Wasserstoffversprödung ist. Selbst an Werkstoffen, die i. a. als wasserstoffbeständig gelten, läßt sich die Wirkung des H2 nachweisen. So ergab sich an austenitischem CrNi-Stahl ein Wert von x = 1,5. Die stärkste Versprödung zeigte das amorphe Metall Vitrovac 0040 mit x = 9,8.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160605
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 80
    Digitale Medien
    Digitale Medien
    DEUTSCHE GESELLSCHAFT FüR METALLKUNDE EV (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A57 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160609
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 81
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985) 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160701
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 82
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A60 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160702
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 83
    Digitale Medien
    Digitale Medien
    Oberflächenbehandlung von Kohlenstoffasern und mechanische Eigenschaften von Laminaten (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 232-238 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Zusätzliches Material: 18 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160705
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 84
    Digitale Medien
    Digitale Medien
    Bruchmechanische Untersuchungen zum KriechrißwachstumAuszugsweise vorgetragen auf der 16. Sitzung des DVM-Arbeitskreises „Bruchvorgänge“, 21./22. 2. 1984 in Karlsruhe. (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 223-228 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Fracture Mechanics Investigation of Creep Crack GrowthThe investigations show that the creep crack growth rate can be determined continously with the single specimen partial unloading compliance technique and with the direct current potential drop technique with similar accuracy for temperatures up to 800°C and testing times up to three month so far.The creep crack growth rates can be correlated to the loading parameter C*-Integral for the two materials X6 Cr Ni 18 11 (similar to A 304 ss) and X 10 NiCrAITi 32 20 (Incoloy 800 H) and for the compact specimens and centre notched tension specimens under consideration here. A description of the creep crack growth rate through the stress intensity factor K yields size and geometry dependent creep crack growth curves.
    Notizen: Die Untersuchungen zeigen, daß sich das Kriechrißwachstum kontinuierlich, d. h. ohne Versuchsunterbrechung mit etwa gleicher Genauigkeit sowohl mit dem Verfahren der partiellen Entlastungen als auch mit dem Gleichstrompotentialverfahren bei Temperaturen bis zu 800°C und auch längeren Versuchsdauern (bisher bis zu 3 Monaten) ermitteln läßt.Für die beiden untersuchten Werkstoffe X6CrNi 18 11 und X10 Ni-CrAlTi 32 20 und die betrachteten Kompaktproben und innengekerbten Flachzugproben lassen sich die Kriechrißwachstumsgeschwindigkeiten durch den Beanspruchungsparameter C* beschreiben. Eine Beschreibung durch den Spannungsintensitätsfaktor K liefert von der Probengröße bzw. Probengeometrie abhängige Rißwachstumskurven.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160703
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 85
    Digitale Medien
    Digitale Medien
    Approximation of Tabulated Normalized Stress intensities by chebyshev polynomials (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 228-232 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Approximation tabellierter bezogener Spannungsintensitäten durch Chebycheff-PolynomeFür bruchmechanische Rißfortschrittsanalysen müssen sowohl Angaben über das Rißfortschrittsgesetz als auch über die für die spezielle Belastungskonfiguration gültigen Formfaktoren vorliegen. In der Regel sind beide Größen zunächst nur als Folge einzelner Datenpunkte gegeben. Für einen effektiveren Einsatz von Rechenanlagen müssen diese Werte zuerst durch eine analytische Funktion angepaßt werden. Während das Rißfortschrittsgesetz leicht aus den Meßwerten hergeleitet werden kann, existiert für die Formfaktoren keine Modellfunktion, die alle denkbaren Lastfälle umfaßt. Mit dem Approximationsverfahren von Chebyshev ist dem Anwender ein rechnerfreundliches Verfahren an die Hand gegeben, das keine Modellannahmen enthält und universell anwendbar ist.
    Notizen: One of the fundamental problems in the application of fracture mechanics is to calculate the crack propagation under alternating load. For these calculations the crack propagation law and the normalized stress intensities are needed. Normally both functions are known only as a set of discrete measured or calculated data. For a more efficient use of computers it is necessary to represent the discrete values by an analytical function. While it is easy to derive the crack propagation law from measured points, there does not exist a convenient model for the normalized stress intensities, which comprises all conceivable load conditions. Therefore, a model-free general approach is suggested, which uses the approximation method according to Chebyshev.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160704
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 86
    Digitale Medien
    Digitale Medien
    Untersuchungen zur Deutung des Dauerschwingverhaltens von CoCrMo-Gußlegierung, dargestellt an Brüchen von Endoprothesen (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 239-246 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Studies for the Interpretation of Fatigue Behavior of CoCrMo Cast Alloy Presented on Fatigue Failures of EndoprothesesExaminations were preformed on the fractured surfaces of appliances made from CoCrMo cast alloy, which were broken in fatigue failures and used in prothetical surgery as endoprotheses. The examinations were performed on behalf of scanning electron microscope. During the examinations of three appliances which were broken in patients, it was found that for the failure of endoprotheses broken in fatigue, the number and distribution of microporosity was also responsible.
    Notizen: Rasterelektronenmikroskopische Untersuchungen wurden durchgeführt an Bruchflächen von im Dauerbruch gebrochenen Teilen aus einer CoCrMo-Gußlegierung, die in der chirurgischen Prothetik als Endoprothese eingesetzt wird. Bei den Untersuchungen von Bruchflächen von drei in Patienten gebrochenen Endoprothesen stellte sich heraus, daß für die im Dauerbruch gebrochenen Endoprothesen auch die Zahl und die Verteilung der Mikrolunker mitverantwortlich waren.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160706
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 87
    Digitale Medien
    Digitale Medien
    Zur Aussagefähigkeit der Härtemessung von Thermoplasten (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 246-252 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: On the Efficiency of Information of Thermoplastics' Hardness MeasurementsIn the present study results of penetration depth measurements as a function of (loading) time are given for 10 thermoplastics using an automated test appliance. The specimens' temperatures have been varied at several stages between room temperature and 100°C. At each stage time-dependent hardness curves H (t) have been derived. The findings permit a more efficient classification of the material's behaviour than it is possible by the aid of conventional hardness testing (so-called „one-point-measurement“). So the concept of hardness curves H (t) ought to be taken into consideration on the occasion of future revision of hardness test standards.
    Notizen: In der vorliegenden Arbeit wurden an 10 verschiedenen Thermoplasten mittels eines automatisierten Prüfstandes Eindringmessungen vorgenommen. Bei zwischen Raumtemperatur und 100°C variierter Prüflingstemperatur wurden die Eindringtiefen in Abhängigkeit von der Belastungsdauer aufgenommen und daraus die entsprechenden Härteverlaufskurven H(t) abgeleitet.Die gefundenen Zusammenhänge machen deutlich, daß mit Hilfe dieser Konzeption eine deutlich bessere (aussagefähigere) Werkstoffbeurteilung möglich ist als über die konventionelle - derzeit normgerechte - Einpunkt-Härtemessung. Es erscheint naheliegend, diese Konzeption im Bereich der technischen Regelwerke zu berücksichtigen.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160707
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 88
    Digitale Medien
    Digitale Medien
    Fügen von Aluminiumwerkstoffen (Schweißen, Löten, Kleben). Von Prof. Dr.-Ing. L. Dorn und 4 Mitautoren. 240 S., DM 48,-, ISBN 3- 88508-875-4 (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 257-257 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160709
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 89
    Digitale Medien
    Digitale Medien
    Widerstandsschweißen - Wirtschaftlichkeit, Produktivität, Qualität. Vorträge der gleichnamigen Sondertagung in Essen im Mai 1985, 127 S., 184 Abbildungen, 30 Tabellen, 1985. DM 78,- (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 257-257 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160710
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 90
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A65 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160712
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 91
    Digitale Medien
    Digitale Medien
    Ermittlung mechanischer Kenndaten von Kohlenstoffaserverstärktem Kohlenstoff (CFC) mit dem Biege- und Zugversuch (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 252-257 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Research on Mechanical Data of Carbon Reinforced Carbon (CC) in Bending and Tensile ModeCC is a ultra high temperature material used until 2200°C in inert atmospheres. The testing geometries of reinforced carbon (CC) are not standardized in West Germany today. Therefore the SIGRI GmbH has defined material specific geoand tensile mode. It is shown, that the tensile strength has a higher level than the bending strength when the laminate orientation is (0/90°). When the laminate has a (0/± 45/90°)-orientation, the relation is inverted. If the laminate orientation is known, the fracture mode can be predicted.
    Notizen: CFC ist ein Hochtemperaturmaterial, welches bei hoher mechanischer Belastung bis zu 2200°C unter Inertatmosphäre eingesetzt werden kann. Da in Deutschland für CFC keine Materialprüfnormen existieren, hat die SIGRI GmbH materialspezifische Prüfgeometrien entwickelt. Gemessen wurde die Biegefestigkeit, die Zugfestigkeit und die interlaminare Scherfestigkeit. Weiter wurden hierzu die entsprechenden Prüfkörpergeometrien entwickelt. Es wird außerdem gezeigt, daß bei einem (0°/90°)-CFC-Verbund die Zugfestigkeit in 0°-Richtung geprüft, deutlich höher ist als die Biegefestigkeit; bei einem (0°/±45°/90°)-Laminat ist es gerade umgekehrt. Bei bekanntem Laminataufbau läßt sich der Bruchmodus voraussagen.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160708
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 92
    Digitale Medien
    Digitale Medien
    Metallurgie der Schweißung nichtrostender Stähle. Von E. Folkhard, 1. Auflage, Springer-Verlag Wien, New York. 1984, 279 S., 113 Abbildungen, 24 Tabellen, gebunden DM 94,- (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 257-258 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160711
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 93
    Digitale Medien
    Digitale Medien
    Masthead (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985) 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160801
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 94
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A68 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160802
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 95
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A74 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160804
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 96
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A73 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160803
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 97
    Digitale Medien
    Digitale Medien
    Investigations into the fatigue crack initiation and propagation behaviour in austenitic stainless steel X5 CrNi 18 9 (1.4301) (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 270-276 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Untersuchungen zur Einleitung und zum Wachstum von Ermüdungsrissen am austenitischen rostfreien Stahl X5 CrNi 18 9 (1.4301)Lastkontrollierte Ermüdungsrißwachstumsversuche wurden an Dreipunktbiegeproben durchgeführt. Der austentitische rostfreie Stahl X5 CrNi 18 9 (Werkstoff-Nr. 1.4301, artgleich dem AISI 304) wurde untersucht. Für dieses hochzähe Material wurde die Rißinitiation und die Rißausbreitung in Form der linear elastischen Analyse selbst für den Bereich höchster Plastizität diskutiert. Die Kurve des Einsatzes des stabilen Rißwachstums während des Ermüdungsvorganges sowie die stabile Rißausbreitung bis in den Bereich hoher Plastizität werden diskutiert. Vom Standpunkt der lastkontrollierten Ermüdung aus wird dargelegt, daß der Abstand zwischen Rißeinleitung und der Rißlänge bei dem „End-of-Life“-Zustand groß ist.
    Notizen: Controlled load fatigue-crack growth rate tests were conducted using three point bend type specimens. The austenitic stainless steel X5 CrNi 18 9 (material number 1.4301, similar to AISI 304) was tested. For this high toughness material, the crack initiation and crack propagation is discussed in terms of linear-elastic analysis even for the highest plasticity regime. The curve for the onset of stable crack growth during fatigue starting from a notch is discussed as well as the stable crack growth up to large plasticity. From the standpoint of load controlled fatigue it is indicated that the time between crack initiation and crack length at the „end of life“ is large.
    Zusätzliches Material: 12 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160806
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 98
    Digitale Medien
    Digitale Medien
    Herstellung, Eigenschaften und Anwendung von reaktionsgebundenem, siliziuminfiltriertem SiliziumkarbidGehalten als Gedenkvortrag für das verstorbene Mitglied des Fachausschusses Verbundwerkstoffe der DGM, Dr. Schlichting (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 277-285 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: Fabrication, Properties and Application of Reaction-Bonded, Siliconized Silicon CarbideThe fabrication process of reaction-bonded, siliconized silicon carbide (SiSiC) is described and the important details of the fabrication are discussed. The material is discussed in therms of its microstructure and properties. Furthermore some fields of possible applications of this ceramic material are shown.
    Notizen: Die Herstellung von reaktionsgebundenem, siliziuminfiltriertem Siliziumkarbid (SiSiC) wird beschrieben und wichtige Details der Prozeßschritte diskutiert. Der Werkstoff wird hinsichtlich seines Gefüges und seiner Eigenschaften vorgestellt und es werden mögliche Anwendungsfelder für diesen keramischen Werkstoff aufgezeigt.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160807
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 99
    Digitale Medien
    Digitale Medien
    MOCH-Methode - ein Beitrag zur Haftungsbestimmung von Schichten (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. 286-291 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Beschreibung / Inhaltsverzeichnis: MOCH-Method - a Contribution to the Determination of Adhesion of CoatingsA method is proposed to determine the fracture mechanics characteristics. A „crack“ is produced in a well defined area by partial contamination. K- and G-factors are calculated by the compliance method. The fracture surfaces are investigated.
    Notizen: Es wird eine Methode zur Ermittlung bruchmechanischer Kennwerte am Beispiel von PVD-Cr-Schichten vorgestellt. Durch partielle Kontamination wird in einem definitiven Bereich ein „Anriß“ erzeugt. Mit Hilfe der Compliance-Methode werden K- und G-Faktoren errechnet. Die Bruchflächen werden untersucht.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160808
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 100
    Digitale Medien
    Digitale Medien
    Nachrichten - Hinweise (1985)
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 16 (1985), S. A75 
    Details
    ISSN: 0933-5137
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Maschinenbau
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/mawe.19850160810
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...