Bibliothek

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
  • 1975-1979  (15)
  • 1880-1889
  • Physics  (7)
  • Rats  (4)
  • Ethanol concentration  (2)
  • Myoepithelial cells  (2)
  • Rhesus monkeys  (2)
Datenquelle
Materialart
Erscheinungszeitraum
Jahr
Schlagwörter
  • 1
    Digitale Medien
    Digitale Medien
    Concurrent etonitazene and water intake in rats: Role of taste, olfaction, and auditory stimuli (1979)
    Springer
    Psychopharmacology 64 (1979), S. 1-7 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Etonitazene ; Etonitazene reinforcement ; Concurrent schedules ; Choice procedures ; Rats ; Taste ; Olfaction ; Auditory stimuli ; Discriminative stimuli ; Conditioned reinforcers ; Fixed-ratio schedules
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Etonitazene and water were concurrently available to four rats during daily 1 h sessions in operant conditioning chambers equipped with two levers and two liquid dippers. A food-induced training procedure was used whereby etonitazene drinking was rapidly established by presenting rats with gradually increased drug concentrations with their daily food ration. When food was subsequently removed from the session and given post-session, etonitazene responding persisted. The rats were subsequently trained on fixed-ratio (FR) schedules with concurrent access to etonitazene and water. The number of dipper presentations compared with etonitazene concentrations (0.078–10.0 μg/ml) resulted in a typical inverted U-shaped function while etonitazene intake (μg/kg) increased directly with concentration. After drinking large quantities of etonitazene the rats showed ataxia, hyper-activity, and stereotypy. Extinction tests demonstrated that rats could discriminate between etonitazene and water on the basis of one dipper full of each liquid; the amount of etonitazene in one dipper was 0.0078 μg. Further tests showed that this discrimination was based on taste or immediate post-ingestional feedback rather than olfactory cues. An auditory stimulus was presented concurrently with responses on the drug lever; however, there was no difference in responding for the drug in the presence or absence of this stimulus except at the lowest concentration. After the extinction tests, when the lowest drug concentration was again available with concurrent water, responding was substantially higher in the presence of stimulus associated with availability of etonitazene. The results extend previous work on oral narcotic intake to a lever-press concurrent choice procedure which is sensitive to reinforcing effects of the drug at low concentrations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427336
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Ethanol-reinforced behavior of rats with concurrent access to food and water (1978)
    Springer
    Psychopharmacology 59 (1978), S. 7-11 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Concurrent schedule ; Ethanol drinking ; Water drinking ; Food deprivation ; Food satiation ; Ethanol concentration ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Dippers filled with water or an ethanol solution were presented to male Wistar rats contingent on lever-pressing under a concurrent fixed-ratio 1 (water) fixed-ratio 1 (ethanol) schedule. During Phase I, when maintenance feedings were given during instead of following the daily 3-h sessions, the feedings increased drinking of both 8% (w/v) ethanol and water, with 8% ethanol being consumed in greater volumes than water. In Phase II, a 28-day transitional period from the food-deprived to the food-satiated state, continuous access to food during 3-h sessions moderately decreased 8% ethanol intake, and increased water intake and total liquid intake (water plus 8% ethanol). In Phase III, concurrent water and ethanol intake of food-satiated rats was compared over two identical series of ethanol concentrations (8, 11.3, 16, 22.6, 32, and 8% retest). Food was freely available in both the operant conditioning chambers and home cages. The number of dipper presentations of ethanol exceeded presentations of water for each rat at each concentration studied. Presentations of water were low in number and did not vary with the ethanol concentration. As the ethanol concentration was increased, the number of ethanol presentations decreased, while the quantity consumed (mg/100 g body weight/h) generally increased.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00428023
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Etonitazene as a reinforcer: Oral intake of etonitazene by rhesus monkeys (1978)
    Springer
    Psychopharmacology 59 (1978), S. 225-229 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Rhesus monkeys ; Etonitazene HCl ; Etonitazene concentration ; Etonitazene reinforcement ; Fixed-ratio schedules ; Etonitazene drinking ; Oral self-administration
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Drinking of etonitazene HCl was studied in three rhesus monkeys during daily 3-h sessions. As the drug concentration was increased, the number of liquid deliveries decreased, and etonitazene intake (μg/kg body weight) increased. As fixed-ratio (FR) requirements were increased, rate of responding increased, and liquid deliveries slightly decreased. When water was substituted for the drug, there was a large increase in responding for several sessions, followed by a slow decline to low rates. When etonitazene was reintroduced, responding abruptly increased to previous drug levels. These data suggest that etonitazene can serve as a positive reinforcer when taken orally by rhesus monkeys.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00426626
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Ethanol drinking by rhesus monkeys as a function of concentration (1978)
    Springer
    Psychopharmacology 57 (1978), S. 133-136 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Rhesus monkeys ; Ethanol reinforcement ; Ethanol concentration ; Blood ethanol level ; Ethanol drinking ; Fixed-ratio schedules ; Intoxication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Ethanol deliveries maintained fixed-ratio (FR) responding of three rhesus monkeys during daily 3-h sessions. At FR values of 8 or 16, ethanol concentration was varied in the sequence 0 (water), 8, 11.3, 16, 22.6, 32, 8, and 0% (w/v). As the ethanol concentration increased, number of liquid deliveries decreased, although intake of ethanol (g/kg/session) increased somewhat. Blood ethanol levels were usually greater than 200 mg% and occasionally greater than 300 mg%.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00426877
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Effects of scopolamine on variable intertrial interval spatial alternation and memory in the rat (1976)
    Springer
    Psychopharmacology 49 (1976), S. 131-137 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Memory ; Storage ; Scopolamine ; Alternating discrimination ; Variable intertrial interval spatial alternation ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A repeated measures procedure, variable intertrial interval (ITI) spatial alternation, was used to assess scopolamine effects on memory, and to compare effects of the drug on discrimination processes with effects on storage. Rats learned in two stages to press left and right levers in alternation on discrete trials separated by 5 different ITI's ranging from 2.5 to 40 s and presented in random order during the experimental session. In the first stage, alternating discrimination, alternation was controlled by a light on over the correct lever at the time of the trial; in the second stage, variable ITI spatial alternation, a centrally located panel light signalled all trials and alternation was controlled by stimuli from prior trials (‘memory’). Alternation response occurrence declined moderately (but significantly) with increasing ITI duration in both the alternating discrimination and variable ITI spatial alternation stages; response occurrence was also significantly decreased by scopolamine treatment in both stages. Accuracy of alternating discrimination performance was not significantly altered by either ITI duration or scopolamine treatment. Accuracy of variable ITI spatial alternation performance on a trial varied inversely with the duration of the ITI that preceded the trial. Scopolamine treatment significantly reduced accuracy of lever pressing in variable ITI spatial alternation but did not alter the slope of the curves relating accuracy to ITI duration. These effects indicate that the drug impaired discrimination processes but did not alter memory storage.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00427281
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Ethanol as a reinforcer for rats: Effects of concurrent access to water and alternate positions of water and ethanol (1975)
    Springer
    Psychopharmacology 43 (1975), S. 19-23 
    Details
    ISSN: 1432-2072
    Schlagwort(e): Ethanol ; Ethanol Drinking ; Water-Ethanol Choice ; Concurrent Schedules ; Ethanol Concentration ; Ethanol Reinforcement ; Rats
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Water and ethanol solutions were concurrently made available on a continuous reinforcement schedule to 4 food-deprived male albino rats during daily 1-hr sessions in an operant conditioning chamber equipped with 2 levers and 2 liquid dippers. The number of ethanol reinforcements substantially exceeded the number of water reinforcements for each rat at each concentration studied (8, 16, and 32% w/v). Water reinforcements were low in number and did not vary with ethanol concentration. As the ethanol concentration was increased, the number of ethanol reinforcements obtained decreased, while the quantity consumed (mg/100 g of body weight/hr) increased. The highest rate of responding occurred at the beginning of the session.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00437609
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Larval adhesive organs and metamorphosis in ascidians (1977)
    Springer
    Cell & tissue research 183 (1977), S. 423-444 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Ascidian larva ; Adhesive papillae ; Settlement ; Myoepithelial cells
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The larva of Distaplia occidentalis bears three cup-shaped adhesive papillae, each with a prominent axial protrusion. At the onset of metamorphosis these organs rapidly evert through fenestrations in the cuticular layers of tunic exposing hyaline caps of adhesive. Additional adhesive material is secreted from collocytes during eversion. The stickiness of the papillae facilitates attachment to a variety of substrates. Each papilla is composed of more than 900 cells; six different types were identified. The wall of the cup contains about 260 myoepithelial cells with long attenuated processes. These extend from the rim of the cup to the base in the parietal (inner) layer. The apices of the myoepithelial cells are held in place by 11 pairs of specialized anchor cells bearing long bulbous microvilli. When the myoepithelial cells contract they force the axial protrusion forward and transform the papilla into a hyperboloidal configuration. The papilla is innervated by small motor fibers, but sensory fibers were not detected. The adhesive papillae of Distaplia are discussed in relationship to nine other recognizable types of papillae in the ascidians.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00225658
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Brachiopod tentacles: Ultrastructure and functional significance of the connective tissue and myoepithelial cells in Terebratalia (1977)
    Springer
    Cell & tissue research 185 (1977), S. 17-42 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Brachiopod tentacles ; Connective tissue ; Myoepithelial cells ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the tentacles of the articulate brachiopod Terebratalia transversa has been studied by light and electron microscopy. The epidermis consists of a simple epithelium that is ciliated in frontal and paired latero-frontal or latero-abfrontal longitudinal tracts. Bundles of unsheathed nerve fibers extend longitudinally between the bases of the frontal epidermal cells and appear to end on the connective tissue cylinder; no myoneural junctions were found. The acellular connective tissue cylinder in each tentacle is composed of orthogonal arrays of collagen fibrils embedded in an amorphous matrix. Baffles of parallel crimped collagen fibrils traverse the connective tissue cylinder in regions where it buckles during flexion of the tentacle. The tentacular peritoneum consists of four cell types: 1) common peritoneal cells that line the lateral walls of the coelomic canal, 2) striated and 3) smooth myoepithelial cells that extend along the frontal and abfrontal sides of the coelomic canal, and 4) squamous smooth myoepithelial cells that comprise the tentacular blood channel. Experimental manipulations of a tentacle indicate that its movements are effected by the interaction of the tentacular contractile apparatus and the resilience of the supportive connective tissue cylinder. The frontal contractile bundle is composed of a central group of striated fibers and two lateral groups of smooth fibers which function to flex the tentacle and to hold it down, respectively. The small abfrontal group of smooth myoepithelial cells effects the re-extension of the tentacle, in conjunction with the passive resiliency of the connective tissue cylinder and the concomitant relaxation of the frontal contractile bundle.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00226666
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Adiabatic compressibility of solutions of ethylene-propylene copolymers in hydrocarbon solvents (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 279-282 
    Details
    ISSN: 0098-1273
    Schlagwort(e): Physics ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Adiabatic compressibility measurements are reported on solutions in hydrocarbon solvents of a low Mw high ethylene content, and of both high and low Mw low ethylene content ethylene-propylene copolymers. In all solutions the observed adiabatic compressibility was lower than the solvent value by an increment which was a function of the solvent type. Comparison of the data for a high and low molecular weight sample of the same copolymer indicates no molecular weight effects. Changes in the composition of the copolymer, as indicated by NMR spectroscopy, have only a slight effect on the adiabatic compressibility. The dominant feature of these studies is the apparent correlation of the chain length of the alkane solvent with the decrement in the compressibility.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1977.180150208
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Acoustic absorption and dynamic compressibility studies of dilute and concentrated solutions of polystyrene in toluene and cyclohexane (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 263-277 
    Details
    ISSN: 0098-1273
    Schlagwort(e): Physics ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Acoustic absorption and adiabatic compressibility measurements are reported on solutions of polystyrene (Mn = 89,000) in toluene and cyclohexane. The data in toluene cover a temperature range from 293 to 343°K and a concentration range of 10-400 Kg m-3 (1-40 wt%). The dependence of acoustic absorption on concentration was found to be linear up to 100 kg m-3, which corresponds to the concentration at which polymer-polymer interactions cause significant changes in the specific viscosity-concentration relationship. Up to 200 kg m-3 the data could be fitted to computations based on an artificial separation of the dispersion into contributions from viscoelastic and segmental processes, using parameters obtained from a study of narrow molecular weight distribution samples at 25 kg m-3. However, neither approach was capable of describing dispersions in the 300, 400 kg m-3 solutions. The modification of the relaxation spectrum observed at the highest concentrations is ascribed to volume and entropy changes associated with alterations of the local environment around a segment of the polymer chain. These changes have their origin in interchain penetration and polymer-polymer contacts, and indicate that ‘entanglement’ is primarily entropic in effect.The adiabatic compressibility exhibited similar deviations from a simple concentration dependence, and allowed estimation of an incompressible volume increment associated with polymer-polymer interactions in the high-concentration entangled matrix. However, the adiabatic compressibilities of solutions of polystyrene, 10-15 kg m-3, in cyclohexane showed no deviations from simple behavior in the region of the theta temperature. Measurements of the adiabatic compressibility of polystyrene in mixtures of cyclohexane-toluene have been used to obtain the relative magnitude of solvent and polymer contributions to the excess compressibility.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1977.180150207
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...