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  • 1
    Digitale Medien
    Digitale Medien
    Semiempirical treatment of the benzophenone molecule as a function of twist angle (1986)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 1590-1597 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The benzophenone molecule has been treated in MNDO, MNDOC, and MINDO/3 approximation as a function of the twist angle α of the phenyl rings. Calculated were (i) the energies of S0 and T1 state, (ii) delocalization of the n and π* orbitals involved in the 3nπ* state, (iii) net atomic charges,(iv) the force constants of the C=O vibration in the S0 and T1 state, respectively, (v) vertical transition energies for T1←S0 and S1←S0, and (vi) the position of upper triplet states. The results are discussed in relation to the spectroscopic properties of the T1 state of a vitreous benzophenone phase. It is concluded that diagonal disorder is due to a significant fluctuation of α causing both a spread of the site energies of the glass-forming molecules and a variation of spin-orbit coupling.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.450452
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  • 2
    Digitale Medien
    Digitale Medien
    Dispersive triplet excitation transport in organic glasses (1986)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 3567-3572 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Time dependent transport of triplet excitations in amorphous benzophenone, anthraquinone, and phenanthrene has been investigated in the temperature range 4.2 K≤T≤100 K by monitoring diffusion-controlled decay of the inhomogeneously broadened 0–0 phosphorescence band of bulk states. The results are in excellent agreement with both the analytic theory of Grünewald et al. and computer simulation of nonequilibrium transport. They indicate the applicability of a stochastic transport model based on asymmetric hopping rates with unrestricted energy relaxation. The time dependence of the ensemble averaged hopping frequency has been determined within three decades of time. It can be approximated by a ν(t)∼(t/t0)α−1 law with time dependent dispersion parameter α.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.450243
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  • 3
    Digitale Medien
    Digitale Medien
    Pressure- and temperature-induced phase transitions in crystalline tetracene monitored via fluorescence resonances in a magnetic field (1985)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 89 (1985), S. 5705-5709 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/j100272a026
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  • 4
    Digitale Medien
    Digitale Medien
    Nonexponential hole burning kinetics in organic glasses (1985)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 89 (1985), S. 4569-4574 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/j100267a031
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  • 5
    Digitale Medien
    Digitale Medien
    Afferent control of walking movements in the stick insectCuniculina impigra (1986)
    Springer
    Journal of comparative physiology 158 (1986), S. 345-349 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. On a motor-driven treadband decerebrateCuniculina usually walked regularly, but only forwards. Animals having only the two forelegs showed the same behavior. Decerebrate animals with just the two hindlegs walked only backwards. 2. In the duration of the electrical activity of the depressor and levator muscles of the trochanter and the extensor and flexor muscles of the tibia, there was no significant difference between the forward walking forelegs of these animals and the active walk of the forelegs of an intact insect.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00603618
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  • 6
    Digitale Medien
    Digitale Medien
    Afferent control of walking movements in the stick insectCuniculina impigra (1986)
    Springer
    Journal of comparative physiology 158 (1986), S. 351-362 
    Details
    ISSN: 1432-1351
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary 1. When a rampwise stretch of large amplitude is applied to the prothoracic femoral chordotonal organ of an active, decerebrate stick insect, usually the first muscles to be activated are the ‘stance phase muscles’, the flexor tibiae, the retractor unguis, and the retractor coxae. Later during the stimulus when the chordotonal organ signals a fairly flexed joint position, the activity of these muscles declines and the ‘swing phase muscles’, the extensor tibiae and the protractor coxae, become active. This sequence takes place in an active animal and is referred to here as response type 1. The same sequence, but with weaker reactions, may occur in an inactive animal (response type 2). There is a gradual transition between these response types and a pure resistance reflex like that shown by a resting, intact animal (response type 4 in an inactive animal; response type 5 in an active animal). 2. Stimulation of the campaniform sensilla or increasing the angle of the subcoxal joint can also elicit response type 1 and 2. 3. During response types 1 and 2 the electrical activity of the muscles and motor neurons involved appears the same as at the end of a stance phase and the transition to a swing phase. 4. In response types 1 and 2 the FETi soma is first hyperpolarized and then strongly depolarized. The common inhibitor (CI) soma responds with a brief depolarization at the onset of stimulation and a longer lasting depolarization at stimulus offset. 5. The existence of response type 2 indicates that the pattern generator for foreleg walking can be in a state in which it is not generating a walking pattern by itself, but can be induced to produce part of a step by appropriate stimulation. Thus, under these conditions it acts like a reflex center.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00603619
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  • 7
    Digitale Medien
    Digitale Medien
    Histopathology of tumour associated sarcoid-like stromal reaction in breast cancer (1988)
    Springer
    Virchows Archiv 412 (1988), S. 231-239 
    Details
    ISSN: 1432-2307
    Schlagwort(e): Breast cancer ; Tumour-associated sarcoid-like stromal reaction ; Tumour immunology ; Host-versus-tumour response ; Sarcoid-like lesion of the axillary lymph nodes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary In 5 cases of invasive ductal and lobular carcinoma of the breast multiple epithelioid and giant cell containing granulomas were detected, localized mainly in circumferential regions, but also in the center of the carcinomas. These granulomas were interpreted as sarcoid-like stromal reactions, occurring as sarcoid-like lesions in uni- and bilateral primaries, in a recurrent tumour, and also in axillary lymph nodes. Histopathologically, these granulomas were not quite uniform, some of them corresponding to typical sarcoidosis, others showing marked proliferations of epithelioid or giant cells or containing fibrinoid exudate or necroses. The granulomas were surrounded by dense infiltrates of mononuclear cells. Tuberculosis and mycosis was excluded. There were no hints of generalized sarcoidosis. Pathogenetically, these are reactions in the tumour stroma of varying intensity, and are not caused by necroses of the tumour tissue nor by microbial infections. Such tumour-associated sarcoid-like stroma reactions are interpreted as a T-cell mediated immune response to an antigen expression of the carcinoma acting as the local trigger; in 2 cases they were connected with sarcoid-like lesions of the axillary lymph nodes. Their occurrence in bilateral carcinoma of the breast points to an immunological disposition for this special kind of host-versus-tumour response. The intensity of these changes in a recurrent tumour reflects an immunological hypersensitivity reaction. The pathogenetic and differential diagnostic aspects of epithelioid granulomas of the female breast in chronic granulomatous mastitis, panniculitis, foreign body reaction, rare infections, and in therapeutically induced sarcoidosis are described and discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00737147
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  • 8
    Digitale Medien
    Digitale Medien
    Modelling of the active reaction of stick insects by a network of neuromimes (1989)
    Springer
    Biological cybernetics 62 (1989), S. 141-150 
    Details
    ISSN: 1432-0770
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Informatik , Physik
    Notizen: Abstract Depending on the activity status of the animal, the control system of the femur-tibia joint in stick insects exhibits either a resistance reflex, or the “active reaction”, a totally different action pattern (Bässler 1988a). Using analog electronic neuron models, several different neuronal circuits are explored that model the active reaction with all its features. The models differ in complexity, redundance and the robustness against small variations of network parameters (e.g. coupling strengths). The circuit with the highest robustness and redundancy requires interneurons with special features, such as found in real animals. When inserted into a closed loop modeling movement and sensory feedback from the periphery, this circuit produces oscillations similar to searching movements found in the real animal. In addition to intracellular recording methods, the authors propose modeling with realistic neuromimes as a complementary method in the investigation of neuronal networks which have well documented input-output relationships.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00203002
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  • 9
    Digitale Medien
    Digitale Medien
    Non-spiking neurons supress fluctuations in small networks (1989)
    Springer
    Biological cybernetics 62 (1989), S. 75-81 
    Details
    ISSN: 1432-0770
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Informatik , Physik
    Notizen: Abstract Certain small networks of spiking interneurons are shown to produce strong fluctuations when modeled with neuromimes. The reasons for these fluctuations are demonstrated and discussed. When one or more of the neuromimes in the circuit were replaced by non-spiking neuromimes, the fluctuations were strongly reduced or disappeared completely. We assume that one of the important functions of nonspiking neurons is to provide precise analog computation while avoiding fluctuation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00217662
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  • 10
    Digitale Medien
    Digitale Medien
    Leg movements of stick insects walking with five legs on a treadwheel and with one leg on a motor-driven belt (1985)
    Springer
    Biological cybernetics 51 (1985), S. 313-318 
    Details
    ISSN: 1432-0770
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Informatik , Physik
    Notizen: Abstract Five legs of a fixed stick insect walked on a double treadwheel. The left hindleg (L3) walked on a motor-driven belt. When the belt was slower than the wheels L3 made less steps than the other legs and when the belt was faster than the wheels it made more steps than the other legs. In the case of slowlier stepping of the “belt-leg”, the motor neurons of the retractor coxae muscle of this leg showed a high activity when the leg was pulled backwards by the belt. This activity was modulated in the step rhythm of the “wheel-legs”. When all legs showed the same stepping frequency (1:1-coordination) the protraction duration of L3 was almost independent of step-period, as well as the lag between onset of protraction of L3 and that of L2. In some cases only L3 could be made to step on the belt even when all other legs did not walk.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00336918
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