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  • Electronic Resource  (19)
  • Chemistry  (13)
  • Catalepsy  (2)
  • Drug discrimination  (2)
  • Highest corner  (2)
  • Syzygies  (2)
Material
  • Electronic Resource  (19)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Applicable algebra in engineering, communication and computing 7 (1996), S. 235-249 
    ISSN: 1432-0622
    Keywords: Standard bases ; Syzygies ; Computer algebra system ; Highest corner ; EcartMethod
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics , Technology
    Notes: Abstract We describe an implementation of a general standard basis algorithm, valid for any monomial ordering compatible with the natural semigroup structure. We concentrate on new strategies which have proved useful, in particular in the non-wellordering case. Moreover, we describe the first implementation of Schreyer's method to compute syzygies and compare it with other, more classical methods. Comparisons of the computing time of several examples in the system SINGULAR give hints as to which strategies should be used in different classes of examples.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Applicable algebra in engineering, communication and computing 7 (1996), S. 235-249 
    ISSN: 1432-0622
    Keywords: Key words Standard bases ; Syzygies ; Computer algebra system ; Highest corner ; EcartMethod.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics , Technology
    Notes: Abstract  We describe an implementation of a general standard basis algorithm, valid for any monomial ordering compatible with the natural semigroup structure. We concentrate on new strategies which have proved useful, in particular in the non-wellordering case. Moreover, we describe the first implementation of Schreyer’s method to compute syzygies and compare it with other, more classical methods. Comparisons of the computing time of several examples in the system SINGULAR give hints as to which strategies should be used in different classes of examples.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2072
    Keywords: Discriminative stimulus ; Catalepsy ; Marijuana ; Δ9-Tetrahydrocannabinol ; Opiate ; Neuroleptic ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The cataleptogenic effect of Δ9-THC was compared to its discriminative stimulus effects in rats. The ED50s for the discriminative stimulus and catalepsy were 0.8 and 4.0 mg/kg, respectively, while their time courses were very similar. The ED50 of Δ9-THC for catalepsy in experimentally naive rats was not different from that in rats trained with the drug discrimination procedure, indicating that the cataleptogenic effect was not appreciably attenuated by long-term exposure to low doses of Δ9-THC. Pharmacologically, the catalepsy produced by Δ9-THC more closely resembled that of haloperidol than of morphine, since anticholinergic pretreatment eliminated the Δ9-THC-induced catalepsy while pre-treatment with naloxone had no effect. Although the cataleptogenic effect of Δ9-THC could be pharmacologically manipulated by anticholinergic pre-treatment, its discriminative stimulus effects were not changed in the same animals. These results demonstrate that distinctive mechanisms of action exist for these cannabinoid-induced behaviors.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2072
    Keywords: Nicotine ABT-418 ; Antinociception ; Hypothermia ; Locomotor activity ; Drug discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract ABT-418, a novel cholinergic ligand, was reported to possess potent cognitive-enhancing and anxiolytic properties in animal models with reduced side effects (Decker et al. 1994; Garvey et al. 1994) suggesting selectivity of effects. In this study, the binding properties of ABT-418 to [3H]-nicotine sites were evaluated and its pharmacology investigated in different tests in laboratory animals. ABT-418 binds with high affinity to3H-nicotine binding sites in the brain with, however, a Ki (6 nM) less than that of nicotine (four-fold). In addition, it acts as a full nicotinic agonist in producing hypomotility, hypothermia and antinociception in mice and engendering nicotine-like responding in rat drug discrimination. The potency of ABT-418 is three to four times less than that of nicotine in all of the animal models, except for hypothermia. In addition, its behavioral effects are completely blocked by mecamylamine, a non-competitive nicotinic antagonist. Although activation of nicotinic receptors by ABT-418 produced several behavioral and pharmacological effects, our results do not suggest high selectivity of different effects as reported by Decker et al. (1994) and Garvey et al. (1994). However, it should be noted that we did not perform some of these tests that produced effects at low doses (Decker et al. 1994) and additional pharmacological studies are needed to establish its selectivity at multiple nicotinic receptors.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 118 (1995), S. 419-424 
    ISSN: 1432-2072
    Keywords: Δ9-THC ; Drug discrimination ; Benzodiazepines ; Specificity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract While many previous studies have shown that a variety of cannabinoids substitute and cross-substitute for Δ9-tetrahydrocannabinol (THC) in drug discrimination procedures, few have systematically examined potential THC-like effects of non-cannabinoid compounds. The purpose of the present study was to delineate further the pharmacological specificity of THC discrimination. Rats were trained to discriminate THC (3.0 mg/kg) from vehicle. Following determination of a dose-effect curve with THC, substitution tests with selected compounds from a variety of pharmacological classes, includingl-phenylisopropyl adenosine, dizocilpine, dextromethorphan, clozapine, buspirone, MDL 72222, muscimol, midazolam and chlordiazepoxide, were performed. Whereas THC produced full dose-dependent substitution, substitution tests with non-cannabinoid drugs resulted in less than chance (50%) levels of responding on the THC-appropriate lever, with the exception of (+)-MDMA (2.5 mg/kg, 50%) and diazepam (3.0 mg/kg, 67%). These results are consistent with those of previous studies and suggest that the discriminative stimulus effects of THC exhibit pharmacological specificity.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 119 (1995), S. 282-290 
    ISSN: 1432-2072
    Keywords: Radial-arm maze ; Δ9-tetrahydrocannabinol (Δ9-THC) ; CP-55,940 ; WIN-55,212-2 ; Anandamide ; Cannabidiol ; Hippocampus ; Antinociception ; Catalepsy ; Rectal temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of the present study was to investigate the disruptive effects of cannabinoids on working memory as assessed in the eight-arm radial-maze. Systemic administration of Δ9-THC, WIN-55,212-2, and CP-55,940 increased the number of errors committed in the radial-maze. CP-55,940 was the most potent cannabinoid in impairing memory (ED50=0.13 mg/kg). Δ9-THC and WIN-55,212-2 disrupted mazechoice accuracy at equipotent doses (ED50 values =2.1 and 2.2 mg/kg, respectively). In addition, systemic administration of each of these agents retarded completion time. Whereas the doses of Δ9-THC and CP-55,940 required to retard maze performance were higher than those needed to increase error numbers, WIN-55,212-2 was equipotent in both of these measures. On the other hand, neither anandamide, the putative endogenous cannabinoid ligand, nor cannabidiol, an inactive naturally occurring cannabinoid, had any apparent effects on memory. A second aim of this study was to elucidate the neuroanatomical substrates mediating the disruptive effects of cannabinoids on memory. Intrahippocampal injections of CP-55,940 impaired maze performance in a dose-dependent manner (ED50=8 µg/rat), but did not retard the amount of time required to complete the maze. The effects of intrahippocampal CP-55,940 were apparently specific to cognition because no other cannabinoid pharmacological effects (e.g., antinociception, hypothermia, and catalepsy) were detected. This dissociation between choice accuracy in the radial-maze and other cannabinoid pharmacological effects suggests that the working memory deficits produced by cannabinoids may be mediated by cannabinoid receptors in the hippocampus.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 24 (1986), S. 233-239 
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Sodium N-(4-sulfophenyl) maleimide (SPMI) and its saturated succinimide counterpart were first prepared according to established methods. Hydrolysis experiments on these monomers monitored by 1H-NMR showed that although SPMI monomer was about 15% hydrolyzed in D2O at 23°C in 24 h. Sodium N-(4-sulfophenyl) succinimide, which is similar in structure to the imide units in the copolymers, was only 1% hydrolyzed after 18 days at 23°C and 29% hydrolyzed after 18 days at 60°C. This indicated that the saturated imide rings in the copolymer might be sufficiently stable to hydrolysis for the copolymers to be useful. However, hydrolysis at high pH demonstrated that the imide rings would be rapidly saponified under alkaline conditions, destroying the structural rigidity that the intact rings might have provided in the copolymer chains. Sodium N-(4-sulfophenyl) maleimide (SPMI) was copolymerized with acrylamide in water at 30°C without cleavage of the imide ring. Water-soluble poly [acrylamide-co-sodium-N-(4-sulfophenyl) maleimide] (PAMSM) samples containing from 7.4 to 64 mol % imide were prepared. Photoacoustic FTIR and 13C-NMR spectra were used to confirm the structure of the copolymers obtained. Elemental analysis was used to determine the imide content of the copolymers, and from this composition data reactivity ratios were calculated for the two component monomers.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The comonomer required, p-maleimidobenzoic acid (MBA) was first prepared in good yield by refinements of published methods. p-Carboxysuccinanilic acid (CSA), and p-succinimidobenzoic acid (SBA), were also prepared to provide models useful for IR and NMR for spectroscopic assignments of the new copolymers. Polymerization of MBA with acrylamide in glacial acetic acid at 60°C gave copolymers with estimated viscosity average molecular weights of 60,000 to 90,000. Yields and viscosity average molecular weights decreased as the MBA to acrylamide monomer feed ratio was increased. The rate of incorporation of MBA into the copolymer rose from 7 to 23% when the mole ratio in the feed was raised from 5 to 20%. Decreasing the initiator concentration increased molecular weights by less than predicted and reduced the yield of copolymer for any given feed ratio of MBA to acrylamide. In all cases about 30-40% of the MBA units in the purified copolymers were hydrolyzed. A change to dimethyl sulfoxide solvent gave good, and poor yields of copolymer at 5 and 10 mol % MBA, respectively, and no copolymer at 20 mol % MBA. Viscosity average molecular weights of the copolymer products prepared in DMSO were somewhat lower than obtained for the copolymers prepared in acetic acid. Polymerization in a DMSO-water mixture gave a negligible yield of polymeric product. Instead, only hydrolysates of MBA precipitated when the coloured polymerization solutions were added to methanol.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N,N-diallylaniline monomer was prepared in good yields, for use in preparation of homopolymer and for copolymerization with acrylamide. Functionalized N,N-diallylaniline monomer, as sodium N,N-diallylsulfanilate, was also prepared in good yields for copolymerization with acrylamide. Both monomers were fully characterized by elemental analysis, IR, and NMR. Poly (N,N-diallylaniline) was obtained by polymerization of a strongly acidic aqueous solution of N,N-diallylaniline initiated with hydrogen peroxide. Spectroscopic data from this homopolymer was used to facilitate spectral assignments of the new copolymers. Copolymers of acrylamide with N,N-diallylamine were prepared at monomer feed ratios of 10, 20, and 30 mol % amine and gave 3.5, 7.4, and 8.9 mol % incorporation, respectively. Similar diallyl monomer incorporation rates were obtained for the copolymerization of sodium N,N-diallylsulfanilate with acrylamide. With 10, 30, and 50 mol % of the sodium salt relative to acrylamide, 3.9, 8.4, and 19.2 mol % incorporation of the diallyl monomer was obtained.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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