ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (957)
  • Life and Medical Sciences  (388)
  • 1
    Electronic Resource
    Electronic Resource
    The radical initiation of vinyl polymerization by α.α.α′.α′-Tetrasubstituted dibenzyls (1972)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 157 (1972), S. 279-298 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Im Temperaturbereich von 60 bis 100°C wird die radikalische Polymerisation von Styrol, Methylmethacrylat und Acrylnitril von α.α′-Dicyanodibenzylen ausgelöst, die in α-und α′-Stellung mit Ester-, Nitril-, Amid- oder Phenylgruppen disubstituiert sind. Bei 100 bis 110°C ist auch das α.α.α′.α′-Tetracarboxymethyldibenzyl aktiv. Vinylacetat und Vinylchlorid werden durch diese Initiatoren kaum polymerisiert.Fur die Polymerisation des Styrols wurden die Bruttogeschwindigkeitskonstanten Kp, für viele Dibenzyle und fur Peroxide vergleichbarer Aktivitat dilatornetrisch bestirnrnt. Norrnalerweise sind die Zeit-Urnsatz-Kurven rnit den Dibenzylen und den Peroxiden vergleichbar; das Tetracyanodibenzyl allerdings bewirkt nur eine unvollstandige Polymerisation.Der große Einfiuß von Substituenten in α-Stellung oder in den Phenylringen der Dibenzyle auf die Polymerisation des Styrols wird diskutiert. Dabei ist auch die Stereochernie wichtig. Die meso-Form des Dinitrildiesters ergibt eine 2.5- bis 3.5 ma1 schnellere Polyrnerisation als das dl-Isornere.Die Dissoziationsgeschwindigkeitskonstanten kd der Initiatoren wurden NMR-spektroskopisch aus der Linienbreite bestirnmt. Die Dinitrildiester sind gute Initiatoren, wahrend die α.α′-Dicyanodibenzyle rnit weiteren Nitril- oder Phenylgruppen in α- und α′-Stellung wenig geeignet sind. SchlieBlich wurde die 1.2-Addition einiger der Dibenzyle an Styrol im Ternperaturbereich von 120 bis 150°C rnit der Methode der chernisch induzierten KernPolarisation (CIDNP) untersucht.
    Notes: The radical polymerization of styrene, methyl methacrylate and acrylonitrile is initiated by α.α′-dicyanodibenzyls α.α′-disubstituted with ester, nitrile, amide or phenyl groups in the temperature range 60 to 100°C and by α.α.α′.α′-tetracarboxymethyldibenzyl at 100 to 110°C. Vinylacetate and vinylchloride show a low reactivity.The overall polymerization rate constants Kp have been determined dilatometrically for styrene initiated by a large number of dibenzyls and comparable peroxides. The styrene polymerization curves are generally comparable with those of peroxides. A notable exception is tetracyanodibenzyl.The strong influence of α- and ring-substituents in the dibenzyls on the styrene polymerization rate is discussed. The stereochemistry is also important : the meso α.α′-dicyanodibenzyls α.α′-disubstituted with ester groups give a 2.5 to 3.5 fold faster polymerization than their dl isomers.The initiator efficiency is related to the kd values, determined from NMR line width measurements. The α.α′- dicyanodibenzyls α.α′-disubstituted with ester groups are good initiators, while those with phenyl groups and nitrile groups are inefficient.Relevant to initiation and termination, the 1.2-addition of some of the dimers to styrene at 120 to 150°C has been studied with chemically induced dynamic nuclear polarization (CIDNP).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1972.021570128
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The cardiac muscle in the pulmonary vein of the rat: A morphological and electrophysiological studyWork done in the Department of Morphology of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, and Institute of Biophysics of the Federal University of Rio de Janeiro. Supported in part by the Fundação de Amparo à Pesquisa do Estado de São Paulo, grant 71/490 - médicas; by the Conselho de Pesquisas da Universidade Federal do Rio de Janeiro, by the Conselho Nacional de Pesquisas (Brasil), and by Banco Nacional de Desenvolvimento Econǒmico (Brasil) Contrato FUNTEC 143. (1975)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 145 (1975), S. 409-433 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The pulmonary veins of albino Wistar rats were studied by means of light and electron microscopy. The media of larger veins consists of cardiac muscle fibers which extend until the vessels attain about 100 μ in diameter. This coat consists of external longitudinal fibers and internal circular fibers. The vasa vasorum are well developed and the capillaries show pseudofenestrations. The numerous adrenergic and cholinergic nerve endings do not form typical motor end-plates as seen in skeletal muscles. The ultrastructure of these media muscle fibers is similar to that of rat hearts. The smooth muscle layer of larger pulmonary veins is not continuous as it is in smaller veins where it forms cushions. Comparisons of albino rats and other rodents reveal striking differences.Action potential shape and propagation velocity (0.5-1.2 m/s) along the myocardial coat of the pulmonary vein were similar to those observed in the left atrium and so was their sensitivity to locally applied acetylcholine. The physiological direction of propagation in rat pulmonary veins is toward the lung. This finding lends support to the hypothesis of a rhythmic, valve-like action of the striated musculature of the pulmonary venous wall during the systole and a possible role in the capacitance of the pulmonary circulation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051450403
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Histological and ultrastructural appearance of the hydroxyapatite-bone interface (1990)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 829-845 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: This article describes the histological and ultrastructural appearance of the interface created in the implantation bed, between bone tissue and implants made of dense sintered hydroxyapatite (HA). Biopsies from dog subjects included: (a) loaded permucosal dental implants for tooth substitution, (b) subperiosteally placed implants for alveolar bone correction, (c) endosseously placed dental root implants to retain ridge form following extraction. The light and electron microscopical results show extensive bone apposition on the osseous sides of the implant surfaces. There is an intimate, direct bone contact without any visible interruption. The bone is of normal lamellar type and continuously connected with the trabecular bone. Bone has grown into the finest surface irregularities of the implant. Collagen fibers of the calcified bone matrix are observed within a distance less than 500 Å from the implant surface. The thin (20-100 Å) electron dense layer at the bone-implant interface resembled the lamina limitans of organic bone matrix, also seen at the inner walls of the osteocytes lacunes. Deposition of bone gives rise to a biologically stable bone-implant interface, without disturbance of the physiological bone turnover. This is seen as very favorable for desired long term fixation of implant to bone.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820240704
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The effect of temperature on nucleotide pool formation in Tetrahymena pyriformis (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 81 (1973), S. 149-151 
    Details
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Warming of exponentially growing T. pyriformis to 34°C results in severe inhibition of nucleotide pool formation. The utilization of the pool for stable RNA synthesis is poorly affected at the high temperature. It thus appears that the synthesis and processing of ribosomal RNA precursors are not primarily impaired at 34°C.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcp.1040810203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Thermally stable polymers: Novel aromatic polyamides (1995)
    Weinheim : Wiley-Blackwell
    Advanced Materials 7 (1995), S. 148-151 
    Details
    ISSN: 0935-9648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19950070208
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Nucleated assembly of mitotic microtubules in living PTK2 cells after release from nocodazole treatment (1981)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 1 (1981), S. 469-483 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; nucleation ; mitosis ; nocodazole ; immunocytochemistry ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The reassembly of microtubules is described in mitotic cells after release from nocodazole-induced block. The formation of microtubules was followed by light microscopic immunocytochemical staining using the PAP method, combined with to-luidine blue staining of the chromatin. The light microscopic observations on whole cells were compared with ultrastructural observations on thin sections. This step is essential to ascertain complete destruction of microtubules during the nocodazole treatment and to correlate immunocytochemical staining with the presence of microtubules.Removal of nocodazole (10 or 1 μg/ml) after a sufficiently long incubation to induce a complete disappearance of microtubules resulted in the appearance of tubulin staining specifically associated with the centromeres and with one or two isolated points in the cytoplasm. Electron microscopy confirmed that the staining was due to the massive accumulation of small microtubules at the kinetochores and centrosomes. Kinetochore nucleation was seen only in association with condensed metaphase-stage chromosomes and not with the less-condensed prophase chromosomes.In a second type of experiment cells were allowed to enter mitosis in the presence of an incompletely active concentration of nocodazole (0.1 μg/ml). The construction of the mitotic spindle was arrested; however, short microtubules were assembled at the kinetochores and centrosomes.These experiments demonstrate that in living mitotic PTK2 cells the kinetochores, as well as the centrosomes, exert a nucleating action on tubulin assembly.The further elongation of microtubules after removal of nocodazole was seen to occur preferentially along axes between the centrosomes and the kinetochores. This resulted in the construction of normal metaphases that evolved through anaphase and telophase. We have attempted to formulate a hypothesis that may explain the oriented assembly that seems to be essential in the construction of the spindle.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970010407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The use of submicroscopic gold particles combined with video contrast enhancement as a simple molecular probe for the living cell (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 105-113 
    Details
    ISSN: 0886-1544
    Keywords: video-microscopy ; colloidal gold ; immunocytochemistry ; microtubules ; receptors ; saltatory motion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We describe a new approach to probe the molecular biology of the living cell that uses small colloidal gold particles coupled to specific ligands. They are visualized in cells by bright-field, video enhanced contrast microscopy. We describe the basic aspects of the technique and provide examples of applications to intracellular motility, cell membrane dynamics, receptor translocation, internalization, and intracellular routing. We also provide examples of the use of this approach in immunospecific labelling of cells and tissue sections.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060207
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    cAMP-induced morphological changes in an immortalized schwann cell line: A prelude to differentiation? (1994)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 29 (1994), S. 20-28 
    Details
    ISSN: 0886-1544
    Keywords: proliferation ; large T antigen ; peripheral nervous system ; cytoskeleton ; microtubules ; myelination ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Schwann cells (SC), the myelinating cells of the peripheral nervous system, show a remarkable capacity to switch from a differentiated state to a proliferative state both during development and peripheral nerve regeneration. In order to better understand the regulatory mechanisms involved with this change we are studying a Schwann cell line transfected with the SV-40 large T gene (TSC). Serum-free medium combined with elevating intra-cellular cAMP levels produced a slower proliferating TSC whose morphology changed from pleiomorphic to process bearing, reminiscent of primary SC in culture. This change was abrogated by colcemid but was unaltered by cytochalasin D, indicating a major role for microtubules. Ultrastructural studies demonstrated numerous microtubules in the cellular extensions which correlated with strong immunocytochemical staining for tubulin in the processes. Analysis of cytoskeletal fractions from the treated cells revealed a greater proportion of tubulin in the polymerized state compared with untreated cells which closely resembled the distribution in primary SC. The cytoskeletal changes observed in the TSC as a result of elevating the intra-cellular cAMP levels may reflect the earliest cellular changes in the induction of myelination. © 1994 Wiley-Liss, Inc.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970290103
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Modern methods for the analysis of urea formaldehyde resins (1976)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 54 (1976), S. 187-201 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Moderne instrumentelle Methoden wurden zur Analyse von Harnstoff-Formaldehyd-Harzen verwendet. Ein ausführliches Studium der Silylierung des Harzes mittels BSTFA (N,O-Bistrimethylsilyltrifluoracetamid) ermöglicht die quantitative gaschromatographische Bestimmung der niedermolekularen Verbindungen Harnstoff, Monomethylolharnstoff und Dimethylolharnstoff. Das Verhältnis zwischen nieder- und hochmolekularen Verbindungen sowie die Mengen an niedermolekularen Verbindungen können mittels GPC-Analyse auf Sephadex LH 20 in Wasser ermittelt werden.Ein vollständiges Bild des Harzes erhält man durch 220 MHz 1H-NMR-Analyse von Lösungen von gefriergetrockneten Proben in DMSO-d6. Zusammen mit den Ergebnissen klassischer chemischer Analysen ergeben die Resultate der drei genannten Techniken einen guten Überblick über den Aufbau eines Harnstoff-Formaldehyd-Harzes.
    Notes: Modern instrumental techniques were used for analysing water-based urea-formaldehyde resins. An exhaustive study was made of the silylation of such a resin with BSTFA (N,O-bistrimethylsilyltrifluoroacetamide). From the gas chromatograms the amounts of urea, monomethylol urea and dimethylol urea can be determined quantitatively, thus giving information on the low molecular weight part of the resin. The ratio of low to high molecular weight components as well as the amounts of several low molecular weight compounds can be estimated from a GPC analysis on Sephadex LH 20 in water. A detailed picture of the resin is obtained when freeze-dried samples are subjected to 220 MHz 1H-NMR analysis in DMSO-d6.An overall insight into the composition of these resins can be gained when the results of the mentioned techniques are combined with those of classical chemical analyses.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1976.050540114
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Aromatic polyamides with imide pendent groupsPresented in part at the IUPAC Symposium on Macromolecules, Strasbourg, July 1981. (1983)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 111 (1983), S. 17-27 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Aromatische Polyamide mit Imidseitengruppen wurden aus 4,4′-Diaminodiphenylether und Imid-Disäurechloriden durch Lösungspolykondensation hergestellt. Die verwendeten Imid-Disäurechloride umfaßten die Disäurechloride von 5-Maleinimidoisophthalsäure, 5-Dichlormaleinimidoisophthalsäure, 5-Tetrahydrophthalimidoisophthalsäure, 5-Hexachlorendomethylentetrahydrophthalimidoisophthalsäure, 5-Endomethylentetrahydrophthalimidoisophthalsäure, 5-Methylenendomethylentetrahydrophthalimidoisophthalsäure, und 5-Phthalimidoisophthalsäure. Das reine aromatische Polyamid aus 4,4′-Diaminodiphenylether und Isophthaloylchlorid wurde zu Vergleichszwecken ebenfalls hergestellt.Polyamidimide sind in polaren organischen Lösungsmitteln löslich und zeigen gute thermische Beständigkeit. Sie können Filme bilden, die gute mechanische Eigenschaften haben. Diejenigen Polyamidimide, die ungesättigte Kohlenstoff-Kohlenstoff-Bindungen enthalten, können durch Erhitzen auf 220°C vernetzen und geben unlösliche Materialien mit verbesserter mechanischer Festigkeit.
    Notes: Aromatic polyamides with imide pendent groups were prepared from 4,4′-diaminodiphenylether and imide-diacid chlorides by solution polycondensation. Imidediacid chlorides used included the diacid chlorides of 5-maleimidoisophthalic, 5-dichloromaleimidoisophthalic, 5-tetrahydrophthalimidoisophthalic, 5-chlorendimidoisophthalic, 5-nadimidoisophthalic, 5-methylnadimidoisophthalic and 5-phthalimidoisophthalic acid. The pure aromatic polyamide from 4,4′-diaminodiphenylether and isophthaloyl chloride was also prepared for comparative reasons.Polyamide-imides are soluble in polar organic solvents and show good thermal resistance. They are film-forming and the films have good mechanical properties. Those polyamide-imides which contain unsaturated carbon-carbon bonds may be crosslinked by heating to 220°C, giving rise to insoluble materials with improved mechanical resistance.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1983.051110102
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...