Showing papers by "University of Florence published in 1977"
155 citations
TL;DR: In this paper, the authors derive the classical equations of motion for scalar and spinning particles interacting with an external Yang-Mills field, and obtain a generalized version of the Bargmann-Michel-Telegdi equation, which is valid for a spin - 1 2 particle in an arbitrary external field.
130 citations
TL;DR: Cortisol, androstenedione, testosterone, dehydroepiandrosterone sulphate (DHAS) and free dehydropsine (DHA) were measured in plasma of women affected by amenorrhoea with hyperprolactinaemia and those affected by secondary hypothalamic amenor rhoea.
Abstract: Cortisol, androstenedione, testosterone, dehydroepiandrosterone sulphate (DHAS) and free dehydroepiandrosterone (DHA) were measured in plasma of ten women affected by amenorrhoea with hyperprolactinaemia and eleven women affected by secondary hypothalamic amenorrhoea; twelve normal women at the second day of the menstrual cycle were used as controls. All subjects were hospitalized and 17-ketosteroids, 17OH-corticosteroids and total dehydroepiandrosterone were also measured in urine. Plasma DHAS was increased in all subjects affected by amenorrhoea with hyperprolactinaemia, while plasma DHA and urinary DHA were significantly increased in this group in comparison to other groups. Plasma cortisol, androstenedione and testosterone and urinary 17-oxosteroids and 17OH-corticosteroids were not significantly differnt in the three groups. In subjects affected by amenorrhoea with hyperprolactinaemia treated with bromocriptine a clear decrease of DHAS correlating with a decrease of plasma prolactin was observed. Since in wome DHAS sems to be almost exclusively secreted by the adrenal gland and most of the circulating DHA is dervied from adrenal secretion, these data suggest that human prolactin can stimulate DHAS production by the adrenal cortex.
90 citations
73 citations
TL;DR: Drugs which affect turnover, release and the postsynaptic receptors of DA in IH, the main mediator in the antinociceptive system are investigated.
Abstract: PAIN PERCEPTION,1,2 vomiting,3 arterial blood pressure,4-6 and affect,7 funtions involved in migraine and other idiopathic headache (IH), are partially controlled by dopaminergic systems, therefore dopamine8 (DA) and 5-hydroxytryptamine (5-HT)9,10 may have a role in the pathogenesis of IH. It has been suggested that pain in IH is central in nature and caused by impaired processing of painful stimuli in the central nervous system.11 Impaired pain perception or dysnociception, could be the result of brain deficiency of 5-HT,12-14 the main mediator in the antinociceptive system.15-16 We have therefore, investigated drugs which affect turnover, release and the postsynaptic receptors of DA in IH.
70 citations
TL;DR: In this paper, the coupling between the pseudoclassical spinning particle and an arbitrary gravitational field was studied and it was shown that the spinning particle cannot be coupled directly to the torsion.
68 citations
TL;DR: In this paper, the relationship between geological situation and water chemistry was investigated and a genetic model of the regional geology was proposed, which was used to distinguish some principal hydrochemical types.
56 citations
51 citations
TL;DR: Cluster ruthenium carbonyl hydrides complexes containing ()-DIOP as asymmetric ligand are efficient catalysts for asymmetric reduction of α,β-unsaturated acids at 90-120°C under hydrogen pressure Optical yields up to 68% have been achieved.
49 citations
TL;DR: In this paper, the effect of neutral organic surfactants on charge transfer at a fully covered dropping mercury electrode has been investigated by the polarographic technique, and it was shown that the percentage decrease in the charge transfer rate constant caused by the surfactant does not depend upon the adsorptivity.
41 citations
TL;DR: Growing and transformed 3T3 show a relatively low amount of trypsin removable heparan sulphate (HS) and a relatively high amount of hyaluronic acid (HA) while resting cells exhibit an opposite ratio between the two GAGs, suspected to be more dependent upon growth than upon transformation.
Abstract: Glycosaminoglycans (GAG's) were released by trypsin from the surface of cultured mouse cells (3T3) in two different growing states: during log-growth phase and during resting due to serum starvation. Doubly labelled molecules from resting cells were compared with those from growing as well as from trnsformed cells. Reproducible differences in the elution pattern during ion exchange chromatography and in susceptibility to specific hydrolytic enzymes have been demonstrated: the GAGs pattern of growing normal cells is similar to the pattern of the cells transformed by either Polyoma or SV-40 viruses and very different from the pattern of resting cells. Growing and transformed 3T3 show a relatively low amount of trypsin removable heparan sulphate (HS) and a relatively high amount of hyaluronic acid (HA) while resting cells exhibit an opposite ratio between the two GAG'S. The lowering of HS and the increase of HA in the cell coat is therefore suspected to be more dependent upon growth than upon transformation.
TL;DR: The intraventricular administration of PCh, Ch but not of DMAE also antagonized the effect of HC-3 on striatal ACh level but not on cortical ACh, and no effects were detected following administration of equimolar doses of P choline, PCh or D MAE.
TL;DR: In this paper, an approximate procedure for the solution of boundary value problems concerning diffusion toward planar, spherical and dropping electrodes, as outlined in two previous notes, is generalized to account for adsorption of reactants and products.
TL;DR: In this article, a model for the magnetic field equilibrium of a cool coronal loop is presented, based on observations, and localized interchange stability is evaluated and discussed, as the first step in a subsequent complete magnetohydrod dynamic-stability analysis.
Abstract: We present here a model, based on observations, for the magnetic-field equilibrium of a cool coronal loop. The pressure structure, taken from the Harvard/Skylab EUV data, is used to modify the usual force-free-field form in quasi-cylindrical symmetry. The resulting field, which has the same direction but different strength, is calculated and its variation displayed. Finally, localized interchange stability is evaluated and discussed, as the first step in a subsequent complete magnetohydrodynamic-stability analysis.
TL;DR: In this paper, the methylene blue-methylene blue leucoform (MB-MBL) system in a pH 7.9 aqueous phosphate buffer has been studied on mercury by the single-step chronocoulometric technique.
TL;DR: It is suggested that the electronic density on the aromatic nucleus plays an important role on the interaction of monocyclic compounds with membrane constituents.
TL;DR: In this paper, the authors calculate shear and bulk viscosity of the cosmological fluid for the early universe and find that photon entropy increases by 1 1/1% due to the bulk viscosity in the lepton and plasma eras.
TL;DR: In this paper, nonradiative transitions occurring in color centers are studied by the WKB approximation; in particular the temperature dependence of the emission-intensities in ${\mathrm{Tl}}^{+}$ centers is fairly well accounted for within a nonphenomenological model.
Abstract: Nonradiative transitions occurring in color centers are studied by the WKB approximation; in particular the temperature dependence of the ${A}_{T}$ and ${A}_{X}$ emission-intensities in ${\mathrm{Tl}}^{+}$ centers is fairly well accounted for within a nonphenomenological model.
TL;DR: T1 relaxation measurements on water protons of solutions containing cobalt(II) bovine carbonic anhydrase have been found to be affected by the paramagnetic center, and data are diagnostic of the presence of exchangeable protons in the donor groups of the enzyme, and consistent with a water molecule in the donors set at low pH values.
TL;DR: In this article, the homogeneous catalytic hydrogenation of citraconic and mesaconic acids in the presence of H4Ru4(CO)8[( −)-DIOP]2 gives, in addition to (S)-methylsuccinic acid, a mixture of λ-lactones in ratios which depend on the substrate and reaction temperature.
TL;DR: The color and flavor degrees of freedom are described in terms of Fermi oscillators (quantized Grassmann variables). The unified theories constructed in this way are vector-like as discussed by the authors.
01 Nov 1977
TL;DR: In this paper, a method for determining the surface compressional modulus, as a function of frequency, by the Fourier transformation of the surface tension relaxation function was presented for submicellar aqueous solutions of the surfactants: dimethyldodecylphosphine oxide, sodium dioctylsulfosuccinate and heptaethylene glycol nonylphenyl ether.
Abstract: A method is presented for determining the surface compressional modulus, as a function of frequency, by the Fourier transformation of the surface tension relaxation function. Data are reported for submicellar aqueous solutions of the surfactants: dimethyldodecylphosphine oxide, sodium dioctylsulfosuccinate and heptaethylene glycol nonylphenyl ether. The method appears to be advantageous for rapidity of measurement and for the possibility to obtain data in the low frequency range for very dilute solutions.
Fur die Bestimmung des Oberflachenkompressionsmoduls, zur Funktion der Frequenz, wird ein Verfahren eingefuhrt mittels der Fourier-Transformation der Relaxationfunktion der Oberflachenspannung. Diesbezugliche Ergebnisse submicellarer Losungen verschiedener Tenside (Dimethyldodecylphosphinoxid, Natrium-dioctylsulfosuccinat und Heptaathylenglykol-nonylphenylather) wird berichtet. Die Methode scheint vorteilhaft fur die Geschwindigkeit und fur die Moglichkeit, Werte im Bereich der niedrigen Frequenzen und der sehr niedrigen Konzentrationen zu erzeugen.
Journal Article•
TL;DR: These models of T-B co-operation could provide an interesting tool for studying the differentiation and antibody production in vitro of human B lymphocytes.
Abstract: Purified B lymphocytes obtained from human tonsil cell populations by removing E rosette-forming cells by density sedimentation did not proliferate at three days in response to PHA and Con A, but showed a significant 3H-labelled thymidine incorporation when the PHA response was assessed at day 6 of culture. The 6th-day responses, which was completely abolished by the reduction of T-cell contamination to less than 0-1% by re-rosetting and a second separation, was due in part to a direct activation by PHA of contaminating T cells and in part to a T cell-mediated B-cell response. When purified B cells were stimulated for 3 days by PHA in the presence of an equal number of autologous or homologous mitomycin-treated T lymphocytes a highly significant uptake of 3H-labelled thymidine was demonstrated. The majority of blast cells obtained at day 4 in these cultures were unable to form E rosettes and showed surface immunoglobulin by immunofluorescence stain. This response was markedly decreased by previous treatment of B cells with mitomycin C and it was abolished when B cells were killed by heating at 56degrees C for 1 hr. Purified B lymphocytes from human tonsils did not respond in vitro when cultured for 6 days in the presence of soluble antigens (PPD and Candida). However, a highly significant response to the same antigens could be demonstrated when B cells were cultured in the presence of autologous mitomycin-treated T cells. These models of T-B co-operation could provide an interesting tool for studying the differentiation and antibody production in vitro of human B lymphocytes.
TL;DR: In this paper, it was shown that the reduction rate k f of S 4 O 6 2− in the presence of halides and pseudohalides at sufficiently negative potentials with respect to the point of zero charge satisfies the well-known Butler-Volmer equation corrected for diffuse-layer effects according to Frumkin.
TL;DR: In this paper, the polarographic current-potential characteristics and current-time curves for the reduction of methylene blue (MB) to MBL in a pH 7.9 aqueous buffer have been examined in detail over a wide concentration range.
TL;DR: It was concluded that in the guinea-pig ventricular muscle dopamine induced a positive inotropic effect through both indirect and direct action, and that the latter is due to the activation of beta-adrenoceptors.
Abstract: The positive inotropic effect of dopamine has been studied in isolated ventricular strips of guinea-pig heart.
01 Jan 1977
TL;DR: The methodology of machining tests for data collection, the software performing spectral analysis and the results of the first series of tests are described and discussed and further development in this research field are proposed.
Abstract: The paper reports about an experimental research aiming to investigate the mutual relationships between tool wear and power spectrum of the flexural vibrations of the tool, during cutting, in turning operations. The methodology of machining tests for data collection, the software performing spectral analysis and the results of the first series of tests are described and discussed. Further development in this research field are then proposed.
TL;DR: In this article, the results of a UPS and theoretical study on two classes of compounds containing the S-X(CH 3 ) 2 -S group (X C, Si and Sn), i.e. dithiolanes and the related open-chain species, are reported.
TL;DR: In this paper, the authors derived polarographic currentpotential characteristics and current-time curves for a Nernstian charge transfer O+ ne R with Langmuir or Frumkin adsorption of reactant and/or product via a mathematical procedure based on diffusion-layer approximation.