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  • 1
    Electronic Resource
    Electronic Resource
    Intrachain exciton quenching analysis in conjugated polymers by two-photon spectroscopy (2002)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 116 (2002), S. 3449-3454 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Intrachain exciton quenching in ladder-type polyparaphenylene has been quantified for the first time. Two-phonon absorption and subsequent upconverted photoluminescence of ladder-type polyparaphenylene and polyfluorene has been measured and analyzed with a new theoretical framework for the two-photon absorption saturation. This microscopic analysis determines the number of singlet excitons as a function of the excitation intensity, which is compared to the photoluminescence intensity. The absorption saturation alone perfectly describes the photoluminescence saturation in polyfluorene, whereas in ladder-type polyparaphenylene, exciton–exciton quenching occurs. By measuring in solution, the formation of stacked polymer chains is prevented. Therefore, the quenching is due to intrachain interaction. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1445108
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  • 2
    Electronic Resource
    Electronic Resource
    A unique two-electron, reversible reduction of a binuclear copper(II) complex. Observation of the electrochemical behavior predicted by Polcyn and Shain for the sequential transfer of two electrons at the same potential (1978)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 100 (1978), S. 1931-1932 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00474a052
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  • 3
    Electronic Resource
    Electronic Resource
    Photovoltaic hybrid device with broad tunable spectral response achieved by organic/inorganic thin-film heteropairing (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 81 (2002), S. 556-558 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: By means of laser deposition, spin casting and vacuum evaporation, optoelectronic hybrid devices were manufactured based upon the thin-film heteropairing of a perylene-derived molecule [di-isoquinoline perylene derivative (DQP)] and CdS. The photovoltaic characteristics of the devices are presented and discussed. We demonstrate that by exploitation of relatively high carrier mobilities in the CdS layer and the high photonic yield and deposition ease of the DQP film, efficient and technologically appealing optoelectronic devices are feasible. In addition, bias dependence of the spectral sensitivity demonstrates the versatility of the introduced device concept in light of photonic sensor applications. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1494117
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  • 4
    Electronic Resource
    Electronic Resource
    Two-photon-excited green emission and its dichroic shift of oriented thin-film CdS on glass formed by laser deposition (2002)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 80 (2002), S. 356-358 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The photoluminescence of oriented thin-film CdS on glass formed by laser deposition was investigated employing 200 fs, 1.54 eV laser pulses at room temperature. The ultrafast excitation caused a two-photon absorption process, which results in purely green emission at the band gap. The spectra are fitted very well by the application of the van Roosbroeck–Shockley relation, density of states, and Urbach's rule demonstrating the intrinsic character of the radiative recombination. It is further shown that the energy position of the emission peak depends on the polarization of the impinging laser beam due to the dichroism of the highly oriented films. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1432756
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  • 5
    Electronic Resource
    Electronic Resource
    Concentration of digoxin, methyldigoxin, digitoxin and ouabain in the myocardium of the dog following coronary occlusion (1975)
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 287 (1975), S. 399-411 
    Details
    ISSN: 1432-1912
    Keywords: Glycosides ; Coronary Occlusion ; Myocardial Concentration ; Epicardial Electrocardiogram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 26 mongrel dogs were given a single dose of 0.03 mg/kg tritium-labelled digoxin, β-methyldigoxin, digitoxin or ouabain 2 hrs or 95 hrs following experimental coronary occlusion. Examination of the epicardial ECG was performed by moving from intact to ischemic or necrotic zones. 60 min after glycoside administration the animals were sacrificed and tissue samples from the marked heart muscles areas and from the skeletal muscle were analysed for glycoside content. The early glycoside uptake in acute ischemic or necrotic myocardium was diminished independently of the physicochemical properties of the glycoside. Significantly higher glycoside concentrations (ng/g wet weight) were measured in the injured myocardium 3 hrs after coronary occlusion than 96 hrs afterward (p〈0.005). The values in acute ischemic myocardium varied considerably. This non-homogeneity of glycoside uptake in the acute ischemic heart muscle may partly explain the increased sensitivity to glycosides in myocardial infarction. The decline of glycoside concentration correlates with the alterations in the epicardial ECG. The cardiac effects of cardenolides 60 min after intravenous administration was caused by the unchanged glycoside. In contrast to the myocardium, glycoside accumulation could not be found in the skeletal muscle. The concentrations of digoxin, β-methyldigoxin and digitoxin in the skeletal muscle were significantly higher than the concentration of ouabain, which was rapidly eliminated via the urine.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00500041
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  • 6
    Electronic Resource
    Electronic Resource
    Vergleichende hämodynamische Untersuchungen über die extrarenale Wirkung von Furosemid und Ethacrynsäure (1975)
    Springer
    Journal of molecular medicine 53 (1975), S. 1133-1134 
    Details
    ISSN: 1432-1440
    Keywords: Furosemide ; ethacrynic acid ; haemodynamic ; Furosemid ; Ethacrynsäure ; Hämodynamik
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 12 Patienten (1–4 Monate nach akutem Myocardinfarkt) wurde das Verhalten hämodynamischer Parameter in Ruhe und unter Belastungsbedingungen vor und nach i.v. Injektion von Furosemid und Ethacrynsäure untersucht. Herzzeitvolumen, Herzfrequenz und arterieller Druck zeigen nach Applikation von Furosemid und Ethacrynsäure keine signifikanten Veränderungen. Während nach Injektion von Ethacrynsäure (trotz gleich starker Diurese wie nach Furosemid) eine gerichtete Veränderung des diastolischen Pulmonalarteriendruckes (PA d) und rechten Vorhofdruckes (RA) nicht zu beobachten ist, bewirkt Furosemid bereits wenige Minuten nach Applikation eine signifikante Senkung des linksventriculären Füllungsdruckes (PA d) und des rechten Vorhofdrucks (RA). Diese hämodynamischen Veränderungen sind als Folge eines direkten dilatorischen Effektes von Furosemid auf die Kapazitätsgefäße aufzufassen. Eine entsprechende direkte Gefäßwirkung von Ethacrynsäure ist nicht nachzuweisen.
    Notes: Summary The haemodynamic effects of intravenous injections of furosemide and ethacrynic acid were studied in 12 patients during rest and excercise. Cardiac output, heart rate and arterial blood pressure showed no significant changes after injection of furosemide or ethacrynic acid. Few minutes after injection of furosemide there were significant falls of pulmonary artery diastolic pressure and right atrial pressure, whereas no changes were seen after injection of ethacrynic acid. This initial effect of furosemide apparently is of primarily vascular origin, causing an increased peripheral venous capacitance. Ethacrynic acid failed to exhibit any direct vascular effect
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01614283
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  • 7
    Electronic Resource
    Electronic Resource
    1-Aminocyclopropane-1-carboxylic acid — a new intermediate of ethylene biosynthesis (1979)
    Springer
    Naturwissenschaften 66 (1979), S. 264-265 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00571611
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  • 8
    Electronic Resource
    Electronic Resource
    Schalenelemente in gemischer Darstellung: Theorie — Kritik — Beispiele (1978)
    Springer
    Archive of applied mechanics 47 (1978), S. 207-222 
    Details
    ISSN: 1432-0681
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Summary To analyse thin shell structures curved mixed elements are developed and studied from a theorctical vantage point and through the medium of numerical exampels. The investigations show, that the accuracy of mixed shell elements is dependent first of all on the choice of integration variables, while the influence of the order of polynoms is less.
    Notes: Übersicht Zur Berechnung dünnwandiger Schalen wird ein Satz von gekrümmten Elementen mit Ansatzfreiwerten in gemischter Weg- und Kraftgrößendarstellung entwickelt und deren Brauchbarkeit an Hand einiger Beispiele überprüft. Die theoretischen und numerischen Untersuchungen zeigen, daß die Genauigkeit gemischter Elemente in erster Linie von der Auswahl geeigneter Integrationsvariabler abhängt, während die Ordnung der Polynomansätze die Approximationsgüte nur geringfügig beeinflußt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00536408
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  • 9
    Electronic Resource
    Electronic Resource
    Histological Study of Lumbar Intervertebral Disc Herniation in Adolescents (2000)
    Springer
    Acta neurochirurgica 142 (2000), S. 1107-1110 
    Details
    ISSN: 0942-0940
    Keywords: Keywords: Disc herniation; lumbar; adolescence; histology.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary ¶ Herniated intervertebral discs are rare in children and adolescents constituting approximately 1–5% of all patients undergoing surgery for lumbar and lumbosacral intervertebral disc herniation. Preceding traumata and congenital anomalities have been reported as important factors for the pathogenesis of intervertebral disc prolapses in young patients. The present histological study is based upon 15 patients with lumbar disc herniation within an age range from 14 to 19 years. Only in one case, was adequate trauma reported. All patients exhibited degenerative changes of the disc, similiar to those observed in adults. These changes were marked in 11 patients (73%).  Thus, as known from adults, also in isolated traumatic disc herniation of adolescence, pre-existing degeneration of the disc has to be considered. If such changes are present, trauma has the significance of only transitory deterioration of the previous disc degeneration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s007010070037
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  • 10
    Electronic Resource
    Electronic Resource
    Supratentorial recurrences of gliomas. Morphological studies in relation to time intervals with astrocytomas (1977)
    Springer
    Acta neurochirurgica 37 (1977), S. 75-91 
    Details
    ISSN: 0942-0940
    Keywords: Supratentorial astrocytomas ; Recurrences of astrocytomas ; Classification of gliomas ; Recurrence intervals ; Radiotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report 137 recurrent supratentorial astrocytomas. The primary tumours diagnosed on the basis of a grading system with three stages were 72 astrocytomas I and 65 astrocytomas II. In the first group 14% of the recurrences were not changed, 55.5% became astrocytomas II, and 30.5% became glioblastomas. In the second group 55.4% were unchanged, and 44.6% became glioblastomas. The postoperative intervals until reintervention or death were statistically examined. It seems that the recurrence time chiefly depends on the nature of the primary tumour. The transformation of an astrocytoma I to a glioblastoma takes longer than the transformation of an astrocytoma II into a glioblastoma. In about two thirds of all astrocytomas an increase of malignancy is to be expected. From the histological picture it is not possible in an individual case to predict the likelihood or speed of malignant change. With regard to the effect of irradiation the authors conclude that radiotherapy most probably does not produce malignancy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01401927
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