Showing papers by "University of Cagliari published in 1972"
398 citations
TL;DR: It is found that a time-dependent regulation is effective for the sole A transport system (affecting the maximal velocity without substantial changes in K m ) and a comprehensive explanation for previously reported changes with time and intracellular substrate concentration of the kinetic parameters governing the uptake of the analogue.
146 citations
TL;DR: The data suggest that methadone, like butyrophenone and phenothiazine neuroleptics, blocks dopamine receptors in brain.
Abstract: — This study has shown that methadone shares with phenothiazine and butyro-phenoneneuroleptics several pharmacological and biochemical actions:thus, D,L-methadone causes catalepsy and hypothermia, blocks apomorphine-induced gnawing, increases brain homovanillic acid levels and stimulates brain dopamine synthesis. The dextro isomer of methadone is inactive. α-Methyl-tyrosine potentiates and apomorphine reverses methadone-induced catalepsy. The data suggest that methadone, like butyrophenone and phenothiazine neuroleptics, blocks dopamine receptors in brain.
111 citations
TL;DR: In this paper, the proton spin-lattice relaxation time in the laboratory frame, T 1, and rotating frame T 1ρ for polycrystalline cubic (NH 4 ) 2 SiF 6, (NH4 ) 2 SnBr 6 and (NH 3 ) 2 Cl 6 have been measured over a temperature range 60-500°K.
40 citations
TL;DR: A procedure for the isolation of a free cytoplasmic 10S RNA from rabbit reticulocytes is described and evidence that the product synthesized under its direction in a rat liver, cell-free system is globin α-chain is presented.
Abstract: THE biological reality of extra-polyribosomal mRNA and its role as a precursor to polyribosomal RNA have been outlined1,2. Although the occurrence of mRNA activity in cytoplasmic postribosomal supernatant from rabbit reticulocytes3,4 has been reported, the active fraction capable of directing globin synthesis has not been identified. We describe here a procedure for the isolation of a free cytoplasmic 10S RNA from rabbit reticulocytes and present evidence that the product synthesized under its direction in a rat liver, cell-free system is globin α-chain. In the same conditions, polyribosome-derived 10S mRNA5 directed the synthesis of both globin α and β-chains.
38 citations
TL;DR: DNA values were determined for the nine species and within the sibling species of the Anopheles maculipennis group DNA differences were found to be present between the palaearctic and the nearctic populations.
Abstract: DNA values were determined for the nine species: Telmatoscopus meridionalis (family Psychodidae), Dixa obscura (family Dixidae), and Culiseta litorea, Culex pipiens, Aedes caspius, Anopheles labranchiae, Anopheles atroparvus, Anopheles stephensi, and Anopheles freeborni (family Culicidae). The DNA content indicated that the species could be divided into three categories: The Culex group with Culex pipiens, Culiseta litorea and Aedes caspius containing 1.02, 0.92 and 0.99 pg DNA in the haploid set, the Anopheles group including the four Anopheles species A. labranchiae, A. atroparvus, A. stephensi, A. freeborni and Telmatoscopus meridionalis with 0.23, 0.24, 0.24, 0.29 and 0.24 pg DNA and the third group with Dixa obscura containing 0.16 pg DNA. Within the sibling species of the Anopheles maculipennis group DNA differences were found to be present between the palaearctic and the nearctic populations. No deviations could be found between two Culex pipiens populations which were reproductively isolated.
31 citations
TL;DR: ECS markedly increased tryptophan and 5‐hydroxyindoleacetic acid levels in brain, and brain serotonin and plasma tryPTophan levels were unaffected.
Abstract: —ECS markedly increased tryptophan and 5-hydroxyindoleacetic acid levels in brain. Brain serotonin and plasma tryptophan levels were unaffected.
30 citations
TL;DR: In this paper, the free ligand coordination bond takes place through the sulphur atom of thioketonic group and a SN1-type mechanism of the photochemical reactions was pointed out by determining the quantum yields.
24 citations
23 citations
TL;DR: In this article, the stoichiometry and kinetics of C 4 A 3 S paste hydration in the presence of CaSO4, CaSO 4·2H2O, C3S and of C2S have been studied.
23 citations
TL;DR: The effects of cyclic AMP and its dibutyryl derivative on the synthesis of brain monoamines were studied.
Abstract: N6,O2-′Dibutyryl cyclic AMP (dibutyryl cyclic AMP), a derivative of 3′,5′-adenosine monophosphate (cyclic AMP) resistant to phosphodiesterase inactivation, has been reported to stimulate serotonin and melatonin synthesis in the pineal gland in vitro1–3. In brain adenyl cyclase and phosphodiesterase, which catalyse the formation and the inactivation of cyclic AMP, are found chiefly in the synaptosomal fraction of the tissue homogenates4, where vesicles containing monoamine are also present5. These factors prompted us to study the effects of cyclic AMP and its dibutyryl derivative on the synthesis of brain monoamines.
TL;DR: Nei ratti, ild, l-metadone fa aumentare significativamente i livelli di acido omovanillico e stimola il turnover della dopamina nei gangli della base.
Abstract: Nei ratti, ild, l-metadone fa aumentare significativamente i livelli di acido omovanillico e stimola il turnover della dopamina nei gangli della base. Il destro isomero e inattivo.
TL;DR: DNA synthesis in polytenic chromosomes of Anopheles atroparvus has been studied during the third and fourth larval stages and at the beginning of the replication cycle coincides with the moult.
Abstract: DNA synthesis in polytenic chromosomes of Anopheles atroparvus has been studied during the third and fourth larval stages. The beginning of the replication cycle coincides with the moult. With increasing larval age the frequency of nuclei in synthesis decreases continuously to reach 1 per cent in the fourth instar at 48 hours of age. The beginning of synthesis is characterized by asynchrony both among larvae and among nuclei within the same larva. At the beginning of replication the polytenic chromosomes have a discontinuous labelling pattern. The same pattern was observed at the end of reduplication. Whole nuclei and single chromosomal regions seem to reach their maximum degree of polyteny during the third larval stage.
TL;DR: The problem of evaluating the components of lattice magnetic susceptibility of semiconductors depends on knowledge of the density distribution and symmetry of the electron cloud in the polyatomic diamagnetic system as discussed by the authors.
Abstract: THE problem of evaluating the components of lattice magnetic susceptibility of semiconductors depends on knowledge of the density distribution and symmetry of the electron cloud in the polyatomic diamagnetic system
TL;DR: Copper-catalyzed alkaline autoxidation of homocystine originates homocysteinesulfinic acid (HCS) and some chromatographic properties and the NMR spectrum of HCS are reported.
TL;DR: The 1H and 13C NMR spectra of antibiotic Viomycin sulphate and its constituent aminoacids in H2O and D2O were examined in a wide range of pH values.
Abstract: The 1H and 13C NMR spectra of antibiotic Viomycin sulphate and its constituent aminoacids in H2O and D2O were examined in a wide range of pH values. The spectra were analysed by proton spin-spin decoupling experiments and measurements of the relative intensities of the resonance and chemical shift values. Exchange experiments were also carried out and an almost complete assignment of the resonances of the spectra was possible. The data obtained are discussed in terms of possible structures for Viomycin and the presence of intramolecular hydrogen bonds. Some information about the conformation of the molecule is also given. A tentative assignment of the 13C spectrum of Viomycin is given and the experimental 13C chemical shift values compare well with the theoretical ones evaluated by Grant's rule.
TL;DR: La densità in gradiente di saccarosio ed il punto isoelettrico delle particlle virali di poliovirus guanidino-dipendentri non differiscono da quelle del virus guanIDino-sensibile di origine.
Abstract: La densita in gradiente di saccarosio ed il punto isoelettrico delle particlle virali di poliovirus guanidino-dipendentri non differiscono da quelle del virus guanidino-sensibile di origine.
TL;DR: 2-amino-4-thiosulfobutyric acid (HCSS) may be well identified, exploiting its ability to transulfurate spontaneously on cyanide or sulfinic compounds, thus originating homocysteinesulfinic acid (HCS).
TL;DR: In this article, the thermoluminescence glow spectra of ortho, meta and para-hydroxy and aminobenzoic acids have been investigated as obtained through UV excitation at low temperature.
TL;DR: In this article, the glow curves of undoped and doped NaCl crystals are compared in the region of liquid nitrogen temperature and it is found that the doping effect on the thermoluminescence is rather small.
TL;DR: In this paper, a series of triazolines with at least one hydrogen atom at the C-4 position has been prepared for the purpose of differentiating the triazoline with a trans configuration from those with a cis configuration.
Abstract: A series of 1-aryl-5-amino-4,5-dihydro-v-triazoles bearing at least one hydrogen atom at the C-4 position has been prepared. The NMR features of the above compounds have been studied with the purpose of differentiating the triazolines with a trans configuration from those with a cis configuration. It has been shown that the hydrogen atom at C-4 lying on the same side of the amine group at C-5 always resonates at lower field than the hydrogen atom on the opposite side. This rule can be applied for identifying the configuration of the 5-amino-v-triazolines.
TL;DR: Un derivato tiopirimidinico è anche capace di impedire il blocco precocem virus indotto, delle proteino-sinsteis cellulari.
Abstract: Contrariamente ad altri inibitori specifici dei poliovirus che prevengono RNA-sintesi virale ed effetto citopatologico, ma non hano effetto sui danni precoci che l'infezione induce nel metabolismo cellulare, un derivato tiopirimidinico e anche capace di impedire il blocco precocem virus indotto, delle proteino-sinsteis cellulari.
TL;DR: In this paper, the effect of a sharp UV light spot on the electroluminescence (EL) of ZnS micro-crystals was investigated and the Fischer double-injection model was shown to conflict with the results.
Abstract: Experiments have already been reported which provide evidence against the Fischer double-injection model for the a.e. electroluminescence (EL) in ZnS (1). They concern respectively the behaviour of low temperature of the EL yield (2) and the effect of a sharp UV light spot on the EL comets (a). We relate here another experiment which, as will be seen, also conflicts with the Fischer model. I t consists in studying the enhancement of the E1 brightness waves emit ted when the ZnS crystals are irradiated with UV light. This effect, which can be referred to as photoelectroluminescenee (PEL), was previously investigated by some authors (4), mainly by PATEK (5), but only in a rather quali tat ive manner and without succeeding in obtaining definite information about the mechanism of the EL process. To perform our measurements we used condenser shaped EL cells, 0.08 mm thick, filled with ZnS microcrystals embedded in araldite. The crystals were doped with 8.10 -4 Cu, C1 atoms per Zn atom. Both the cell electrodes were built with conducting quartz, to allow the UV light to reach the phosphor crystals. The cell was excited with a 1500 Hz sinusoidal voltage, while it was irradiated with light from a 250 W low-pressure UV lamp supplied with a 50 Hz stabilized voltage. The distance from the lamp to the cell was 30 cm. Light from the cell was detected with a 6810 A RCA phototube placed 20 em away. Suitable collimators and filters were used, to prevent visible light from the lampe reaching the cell and UV light scattered from the cell striking the phototube. In these conditions the EL signal, even though of relevant amplitude, was hidden by a predominant photoluminescence (PL) signal due, besides the ZnS crystals, to araldite. For this reason and taking into account that PL emission was pulsed with a frequency (100 Hz, say twice that of the voltage applied to the UV lamp) very low with respect to that of EL, we connected, after the photomultiplier, a high-pass filter to improve the EL to PL signal ratio.
01 Sep 1972
TL;DR: In this article, a two-parametric minimum-square method of best fitting based on the Debye-Huckel theory was used to calculate the best values of the individual ionic radii and the dependence of the dielectric constant on concentration.
TL;DR: The first quantitativen bestandsaufnahme aus dem mediterranen Raum werden with solchen aus anderen Gebieten verglichen and fur die Untersuchung der Okologie einiger sardischer Stadtvogelpopulationen herangezogen as mentioned in this paper.
Abstract: Ergebnisse der vielleicht ersten quantitativen Bestandsaufnahme aus dem mediterranen Raum werden mit solchen aus anderen Gebieten verglichen und fur die Untersuchung der Okologie einiger sardischer Stadtvogelpopulationen herangezogen. Die Zahl der Brutpaare eines 10,5 ha grosen, charakteristischen Teils der Kleinstadt Oristano (Sardinien) wurde im Fruhjahr 1966 mit Hilfe der Zahl der besetzten Nester von acht sowie der Revier-♂ von drei weiteren Arten ermittelt und kartiert. Die Siedlungsdichte (Abundanz) war im Vergleich mit den Werten in anderen Stadt- und Freilandbiotopen auffallend hoch mit 362,8 Brutpaaren/10 ha. Dies wird auf das grose Nistplatzangebot, „urbane Konzentrationseffekte“, soziales Verhalten der Dominanten und weitere im mediterranen Raum wirksame okologische Faktoren zuruckgefuhrt und als keineswegs uncharakteristisch fur Kustenstadte im Mittelmeergebiet angesehen. Brutbiotope von drei Dominanten uberlagerten sich, da der Einfarbstar(Sturnus unicolor), der Weidensperling(Passer hispaniolensis) und der Feldsperling(P. montanus) vor allem Niststatten am Rande von Garten und Innenhofen besiedelten. Der Einfarbstar war jedoch relativ haufiger im „Kunstfelsenbiotop“ der Stadt als die beiden Sperlinge. Die Konkurrenz am Nistplatz zwischen Einfarbstar und Weidensperling schien hier wegen eines uberaus grosen Nistplatzangebots im Gegensatz zu anderen sardischen Ortschaften nur leicht zu sein. Das seit etwa 75 Jahren beobachtete Vordringen des Feldsperlings auf Sardinien ist von einer Verschiebung der okologischen Nische dieser Art gegenuber ihren ubrigen europaischen Brutarealen begleitet. Feldsperlinge leben auf Sardinien charakteristischerweise in modernen Industrie- und Citybiotopen und scheinen sich hier vornehmlich in diesen und anderen vom Menschen geschaffenen Biotopen auszubreiten, die offenbar von dem Freiland und Ortschaften gleichermasen besiedelnden Weidensperling nicht oder nur teilweise beansprucht werden. Weitere Umweltveranderungen durften die Ausdehnung des Feldsperlings auf Sardinien beschleunigen.
TL;DR: In this article, the effect of substituents on half-wave potential has been studied and the mechanism of the electroreduction is discussed, where the substituent effect is considered.
TL;DR: In this article, the survival probability of a muon penetrating through a thickness x of material is calculated with the Monte Carlo method, considering standard earth as shielding material, and the values of P E (x ) and range distribution R E ( x ) are given for E = 100, 200 and 500 GeV.