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  • Polymer and Materials Science  (4)
  • Intramolecular electron transfer  (3)
  • 25.70.Np  (2)
  • Depression  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Total charge-changing cross sections for neutron-deficient isotopes from58Ni fragmentation (1995)
    Springer
    The European physical journal 352 (1995), S. 69-75 
    Details
    ISSN: 1434-601X
    Keywords: 21.10.Ft ; 25.70.Np ; 27.40.+Z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract At the projectile-fragment separator FRS of GSI, relativistic secondary beams of about 520 MeV/nucleon were produced by fragmentation of a primary beam of58Ni at 650 MeV/nucleon in a beryllium target. By means of aΔE—Bρ—TOF measurement, the fragments have been identified and their charge-changing probabilities in targets of CH2, C, Al, and Pb have been determined. We describe the results for the total charge-changing cross sections in this first paper, whereas a second article deals with the partial charge-changing cross sections. At the drip line, the measured charge-changing cross sections exhaust close to 100% of the total interaction cross sections as calculated with semiempirical models. The measurements at the proton drip line with low-Z targets indicate that only a very small increase of the cross sections may be observed, whereas the measurements with a lead target show that no significant increase of the total charge-changing cross sections is present which would be a hint for low-lying dipole strength. Our experimental data are compared to Glauber-type calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01292761
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  • 2
    Electronic Resource
    Electronic Resource
    Serotonerge Dysfunktion als Folge sozialer Isolation Bedeutung für die Entstehung von Aggression und Alkoholabhängigkeit (1999)
    Springer
    Der Nervenarzt 70 (1999), S. 780-789 
    Details
    ISSN: 1433-0407
    Keywords: Schlüsselwörter Serotonin ; Verhaltensinhibierendes System ; Impulsivität ; Aggression ; Depression ; Key words Serotonin ; Behavior inhibition system ; impulsivity ; Aggression ; Depression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Dysfunction of serotonergic neurotransmission has been associated with two different psychopathological syndromes – impulsive aggressivity resulting form a lack of stimulation of the “behavior inhibition system” on the one hand and the manifestation of clinical depression and compulsive syndromes on the other. The examination of primate behavior provides a model which may reconciliate these seemingly contradictory hypotheses. According to primate experiments, monoaminergic depletion results in anxious and desperate behavior only if the individual has previously been exposed to social isolation stress, which in turn induces a decrease in the central serotonin turnover rate. Young non-human primates who experience early social separation stress are anxious and fearful, while as adults they tend to be aggressive, consume excessive amounts of alcohol and are less intoxicated by alcohol intake. These observation indicate the importance of social separation stress in the pathogenesis of alcoholism and antisocial behavior and may point to prophylactic and pharmacological treatment strategies.
    Notes: Zusammenfassung Eine Dysfunktion serotonerger Transmission wurde mit zwei verschiedenen psychopathologischen Syndromen in Verbindung gebracht. Einerseits wurde der serotonergen Neurotransmission eine wesentliche Rolle in der Stimulation des “verhaltensinhibierenden Systems” zuerkannt und postuliert, daß ein verminderter Serotoninumsatz zur Enthemmung impulsiver und aggressiver Verhaltensweisen führt. Andererseits gibt es Hinweise auf die Bedeutung einer verminderten serotonergen Transmission in der Pathogenese der Depression und der Angsterkrankungen. Eine mögliche Deutung der vordergründig widersprüchlichen Befunde ergibt sich aus der Untersuchung serotonerger Transmission bei Primaten. Eine pharmakogen induzierte Verarmung an monoaminergen Neurotransmittern führt demnach nur dann zu depressionsanalogen Verhaltensweisen, wenn in der individuellen Entwicklung mehrfach Phasen sozialer Isolation durchlebt wurden. Umgekehrt ist soziale Isolation bei jungen Primaten mit einem verminderten Serotoninumsatz, verstärkter Ängstlichkeit und sozialer Inkompetenz assoziiert, während sich bei diesen Primaten im Erwachsenenalter eine erhöhte Aggressivität und Alkoholtoleranz und ein erhöhter freiwilliger Alkoholkonsum nachweisen lassen. Diese Befunde unterstreichen die Bedeutung von Streß- und Lernfaktoren in der Ausgestaltung der psychopathologischen Korrelate einer serotonergen Dysfunktion und verweisen auf mögliche prophylaktische und pharmakologische Behandlungsoptionen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001150050512
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  • 3
    Electronic Resource
    Electronic Resource
    Medikamentenindizierter Kopfschmerz (1999)
    Springer
    Der Schmerz 13 (1999), S. 304-314 
    Details
    ISSN: 1432-2129
    Keywords: Schlüsselwörter Medikamenteninduzierter Kopfschmerz ; Serotonin ; Migräne ; Depression ; Angsterkrankungen ; Key words Drug-induced headache ; Serotonin ; Migraine ; Depression ; Anxiety
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The pathogenesis of drug abuse in patients suffering from drug-induced headache is not known in detail. It is unclear whether drug abuse in chronic daily headache should be classified as a form of drug dependence. Current findings concerning the neurobiological correlates of addictive behavior and affective disorders point to the importance of monoaminergic dysregulation, especially a dysfunction of central serotonergic neurotransmission. We reviewed the literature on drug-induced headache and examined hypothetical pathomechanisms of addiction. Drugs causing drug-induced headache such as paracetamol, coffein and ergotamine interfere with behavior patterns or neurotransmitter systems that are also affected by drugs of abuse. Several drugs that ameliorate acute headache interact with central serotonergic neurotransmission and may affect anxiety and depression in patients with chronic daily headache. Non human primate and human studies revealed mechanisms of serotonergic dysfunction in drug dependence, which may also be relevant for drug-abuse in medication-induced headache. Medication-induced dysfunction of monoaminergic, especially serotonergic neurotransmission, may affect drug dependence by exacerbating mood disorders. Further studies are necessary to assess serotonergic neurotransmission in patients with drug-induced headache and abuse of medication.
    Notes: Zusammenfassung Die Pathogenese des Medikamentenmißbrauchs bei chronischen Kopfschmerzen ist weitgehend unbekannt. Es ist unklar, ob es sich um eine typische Abhängigkeitserkrankung handelt und ob sich monoaminerge neurobiologische Störungen nachweisen lassen, die in vergleichbarer Form auch bei anderen Abhängigkeitssyndromen auftreten. Wir analysierten die vorliegende Literatur zu medikamenteninduzierten Kopfschmerzen im Hinblick auf Befunde zu möglichen neurobiologischen Mechanismen der Abhängigkeitsentwicklung. Schmerzmittel, Koffein und Ergotamine verursachen ähnliche Verhaltensauffälligkeiten oder wirken in vergleichbarer Weise auf monoaminerge Neurotransmittersysteme ein wie Suchtsubstanzen. Eigene bildgebende Untersuchungen zeigten eine Assoziation zwischen einer serotonergen Dysfunktion, affektiven Störungen und der Entwicklung abhängigen Verhaltens, die auch für die Entstehung der medikamenteninduzierten Kopfschmerzen relevant sein könnte. Medikamentös induzierte Störungen der monoaminergen, insbesondere der serotonergen Neurotransmission führen möglicherweise deshalb zur Abhängigkeitsentwicklung, weil sie affektive Störungen verstärken. Weitere Studien sind notwendig, um serotonerge Mechanismen der Entstehung und Aufrechterhaltung des Medikamentenmißbrauchs bei medikamenteninduzierten Kopfschmerzen zu überprüfen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004820050237
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  • 4
    Electronic Resource
    Electronic Resource
    Partial charge-changing cross sections for neutron-deficient isotopes from58Ni fragmentation (1995)
    Springer
    The European physical journal 352 (1995), S. 77-83 
    Details
    ISSN: 1434-601X
    Keywords: 21.10.Ft ; 25.70.Np ; 27.40.+z
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract At the projectile-fragment separator FRS of GSI, relativistic secondary beams of about 520 MeV/nucleon were produced by fragmentation of a primary beam of58Ni at 650 MeV/nucleon in a beryllium target. By means of aΔE—Bρ—TOF measurement, the fragments were identified and their charge-changing probabilities in targets of (CH2) n , C, Al, and Pb placed at the exit of the FRS were determined. Whereas a first article dealt with the total charge-changing cross sections, we describe in this second article the element distributions of these secondary fragments, which are found to depend strongly on the isospin of the secondary projectile as well as on the target material. In the case of the lead target, the influence of the electromagnetic dissociation is clearly visible in the one-proton and two-proton removal channels. The preference for the formation of even-Z fragments is much more pronounced for exotic secondary projectiles than for projectiles close to stability. Calculations with a geometrical abrasion-ablation model allow to understand the global features of the experimental data. However, far from stability, the discrepancies between calculations and experimental data increase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01292762
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  • 5
    Electronic Resource
    Electronic Resource
    Intramolecular Electron Transfer between Terminal 1,4-Dimethoxybenzene Units in Radical Cations with a [2.2](1,4)Naphthalenophane, [2.2](1,4)Anthracenophane, and Pentacene Skeleton (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1161-1170 
    Details
    ISSN: 1434-193X
    Keywords: [2.2](1,4)Naphthalenophanes ; [2.2](1,4)Anthracenophane ; Pentacene ; Cyclic voltammetry ; Radical cations ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Various radical cations, in which two terminal 1,4-dimethoxybenzene units are anellated to [2.2]paracyclophane (2b•+, 3b•+), [2.2](1,4)naphthalenophane (4d•+), and anthracene bridges (5•+), have been studied by ESR and ENDOR spectroscopy. In the syn- and anti-naphthalenophane radical cations 2b•+ and 3b•+ the delocalization of the unpaired electron over both π-moieties and the distinct difference between the first and second oxidation potentials, ΔE = E20 - E10, are evidence for a substantial intramolecular electronic interaction between the two electrophores. Extension of the bridge in 4d•+ and 5 by benzo anellation results in a localized radical cation. Strong intramolecular electronic interaction between the two electrophores is found in the 1,4,8,11-tetramethoxy-pentacene radical cation (5•+). The syntheses of 4d are described.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [2.2]Paracyclophane-4,7,12,15-tetrone, [2.2](1,4)Naphthalenophane-4,7,14,17-tetrone, and 1,4,8,11-Pentacenetetrone Radical Anions - A Comparative ESR Study (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 221-227 
    Details
    ISSN: 1434-193X
    Keywords: 1,4-Benzoquinones ; [2.2]Paracyclophanes ; 1,4,8,11-Pentacenetetrones ; Cyclic voltammetry ; Radical anions ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three types of tetrone radical anions in which two 1,4-benzoquinone units are connected by ethano (1·-, 2·-), [2.2]paracyclophane (3·-, 4·-), and anthracene bridges (5·-, 6·-) have been studied by ESR and ENDOR spectroscopy. The displacement of the unpaired electron over the two π moieties in the [2.2]cyclophane radical anions 1·--4·- and the marked difference between the first and second reduction potentials, ΔE = |E20 - E10| ≥ 0.20 V, are evidence for a substantial intramolecular electronic interaction between the two electrophores. Similar ΔE data for the syn- (3) and anti-naphthalenophanes (4) indicate that most of the intramolecular electronic interaction takes place through the [2.2]paracyclophane bridge. When ion pairing is inhibited by complexation of the cation, the unpaired electron in 5·- and 6·- is also delocalized over the whole pentacenetetrone system at temperatures as low as 160 K.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Intramolecular Electron Transfer between 2,5-Dimethoxy-1,4-phenylene Units in [n.n]Paracyclophane Radical Cations (1998)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 139-148 
    Details
    ISSN: 1434-193X
    Keywords: Paracyclophanes ; Cyclic voltammetry ; Radical cations ; ESR/ENDOR spectroscopy ; Intramolecular electron transfer ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A range of [n.n]paracyclophane radical cations (4·+-12·+), in which two 2,5-dimethoxy-1,4-phenylene units are connected by alkano bridges of varying length, have been studied by ESR and ENDOR spectroscopy. In the [2.2]- and [3.3]paracyclophane radical cations 4·+-6·+, 10·+ and 11·+ the delocalization of the unpaired electron over both π-moieties and the distinct difference between the first and second oxidation potentials, ΔE = E20 - E10, are evidence for a strong intramolecular electronic interaction between the two electrophores. The [5.5] and [7.7] species (8·+ and 9·+) are localized radical cations at low temperature (ca. 220 K). At room temperature, the higher molecular flexibility leads to a significant increase in the number of internal collisions between the electrophores, resulting in a fast (ESR time scale) intramolecular electron transfer. The intermediate [4.4]paracyclophane radical cations 7·+ and 12·+ are apparently also localized radical cations. The close interplanar distance between the two π-moieties, however, facilitates their mutual contacts. In 7·+, the intramolecular electron transfer becomes fast on the ESR time scale at room temperature; in 12·+ the transfer is fast over the temperature range 200-300 K.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Modellgestützte Regelung von WärmeaustauschernVortrag von H. PREISIG auf der GVC-Jahrestagung, 28./30. Sept. 1994 in Aachen. (1995)
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 67 (1995), S. 1472-1476 
    Details
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cite.330671110
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  • 9
    Electronic Resource
    Electronic Resource
    Über die autoxydation ungesättigter verbindungen. V. Mitt. Zur konstitution der polymeren peroxyde von 2,3-dimethylbutadien, isopren und cyclopentadienIV. Mitteilung Makromolekulare Chem. 16 (1955) 21. (1955)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 16 (1955), S. 81-88 
    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: The polymeric peroxides of dimethylbutadiene, isoprene and cyclopentadiene are thermally decomposed and the fragments analyzed. The content of 1,2-structure of the polymeric peroxide of dimethyl-butadiene is about 40-50%, of the polymeric peroxides of isoprene nearly 25%. The polymeric peroxide of cyclopentadiene has only 1,4-structure.The reaction of the polymeric peroxides with perbenzoic acid had been investigated. The presence of peroxy groups in α-position to an ethylenic bond changes their reactivity with perbenzoic acid, decreasing the reactivity of internal double bonds.
    Notes: Die polymeren Peroxyde von Dimethylbutadien, Isopren und Cyclopentadien werden thermisch zersetzt und die erhaltenen Bruchstücke untersucht. Quantitative Bestimmungen von Formaldehyde ergeben, daß das polymere Dimethylbutadienperoxyd zu 40 bis 50%, das polymere Isopreperoxyd zu etwa 25% aus 1,2-Copolymerisaten der Diene mit molekularem Sauerstoff bestehen. Das polymere Cyclopentadienperoxyd entsteht dagegen anscheinend nur durch 1,4-Addition, da der Nachweis des für ein 1,2-Copolymerisat als Zersetzungsprodukt zu erwartenden Glutaconsäuredialdehyds nicht gelang.Es wird außerdem versucht, mit Perbenzoesäure die bei 1,4-Autoxydation zu erwar-tenden kettenständigen Doppelbindungen neben den bei 1,2-Autoxydation zu erwarten-den Vinylseitenketten zu bestimmen. Die Anwesenheit einer peroxydischen Gruppe in α-Stellung zu einer Doppelbindung ändert deren Reaktionsfähigkeit mit der Persäure; sie ist bei kettenständigen Doppelbindungen vermindert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1955.020160112
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  • 10
    Electronic Resource
    Electronic Resource
    Über die authoxydation ungesättigter verbindungen. VI. Mitt. Die autoxydation des 9,11-octadecadiensäuremethylesters (1956)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 18 (1956), S. 406-413 
    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: The Me-ester of 9,11-octadecadienoic acid reacts in 1.2 and 1.4-position with moleculare oxygen to give relatively low molecular oxygen-copolymers. These polymeric peroxides produce autocatalyzing effects in the authoxidation reaction. They are rather resistent and can be stored without showing formation of aldehydes. The reaction of perbenzoic acid with external and internal double bounde standing in α-position to peroxy groups was studied at the examples of allyl-tert.-butyl peroxide and cyclohexenylmethyl peroxide.
    Notes: 9,11-Octadecadiensäuremethylester reagiert mit molekularem Sauerstoff in 1,2- und 1,4-Stellung unter Bildung von relative niedermolekularen Sauerstoff-Copolymerisation. Diese polymeren Peroxyde sind bei der Authoxydation autokatalytisch wirksam. Sie sind recht beständig; die buldung von Aldehyden wurde dei der Aufbewahrung nicht beobachtet. Die Reaktion von end- und von kettenständigen Doppelbindungen, die in Nachbarschaft zu Peroxygruppen stechen, mit Perbenzoesäure wird am Beispiel des Allyl-tert.-Butyl- und des Cyclohexenylmethylperoxyds untersucht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1956.020180135
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