Showing papers by "University of Florence published in 1973"
TL;DR: A three-time level implicit scheme, which is unconditionally stable and convergent, is employed for the numerical solution of phase change problems, on the basis of an analytical approach consisting in the approximation of the latent heat effect by a large heat capacity over a small temperature range as discussed by the authors.
500 citations
150 citations
TL;DR: Guinea-pig hearts, perfused withTyrode containing 8 mM taurine, show a less marked decrease of contractile force when washed out with calcium-free Tyrode than control hearts, and the hypothesis is advanced that taurines increases the affinity of some cell structure for calcium.
114 citations
TL;DR: In this paper, the average potential at the position occupied by the reacting particle in the transition state was derived from a simple model of the double layer in the presence of specific ionic adsorption.
55 citations
TL;DR: The pain from serotonin depletion may represent a chemical approach to the mechanism of central pain, such as thalamic syndrome, and may give a new suggestive light to the serotonin interpretation of migraine and some daily headaches.
Abstract: Vascular supersensitivity to 5-hydroxytryptamine, but not to noradrenaline is observed in volunteers suffering from untreatable migraine, following treatment with parachlorophenylalanine, a specific serotonin depletor A similar supersensitivity at brain level is claimed to explain an unusual systemic pain syndrome developed in 4 patients affected by migraine and treated with this serotonin depleting agent; hyperalgesia, hyperpathia, spontaneous pain, according to the picture of central pain, are demonstrable The pain syndrome is reversible with the drug discontinuation; it reappears promptly when the treatment is started again
48 citations
TL;DR: It is suggested that taurine and isethionic acid react with calcium on the mitochondrial outer membrane and/or intermembrane spaces, increasing mitochondrial calcium-binding capacity and thus affecting mitochondrial oxygen uptake.
41 citations
TL;DR: In this article, the adiabatic potential energy surfaces (APES) of the a 1 g t 1 u electronic configuration of an octahedral complex interacting with doubly degenerate E g modes have been calculated assuming intermediate coupling.
31 citations
TL;DR: In vitro lymphocyte transformation and the precipitating antibody to house dust and mite (Dermatophagoides pteronyssinus) extract were studied in mite‐ and house‐dust sensitive patients and in non‐atopic individuals.
Abstract: Summary
In vitro lymphocyte transformation and the precipitating antibody to house dust and mite (Dermatophagoides pteronyssinus) extract were studied in mite- and house-dust sensitive patients and in non-atopic individuals. House-dust extract was able to induce a significant [2-14C]thymidine incorporation into lymphocytes from house-dust-sensitive as well as non-allergic individuals. An in vitro response to mite extract, even if less marked, was also seen in most of mite-sensitive patients.
By the micro-Ouchterlony and counterimmunoelectrophoresis techniques anti-dust antibodies were found in the serum of all house-dust-sensitive and non-atopic individuals tested. Anti-mite precipitins were detected in a smaller number of subjects.
31 citations
TL;DR: Acute strychrune Moxlcation is seldom observed even in the busiest clinical toxtcology sernces, Nevertheless, acute suychtune mtoxi&on is an interesting, dramatic, and even treatable form of poison if promptly dngnosed and d a rztional therapy u wed out.
Abstract: (1973). Pharmacokinetic Observations on a Case of Massive Strychnine Poisoning. Clinical Toxicology: Vol. 6, No. 4, pp. 533-540.
29 citations
TL;DR: In this article, some particular methods of collecting and treating DSC data for the determination of kinetic parameters in thermal decompositions of solids are suggested, mainly concerned with an extrapolation method to avoid the effect of the sample mass, with an approximate method to obtain the activation energy and the exponent of the decay-law for runs at constant temperature in which the total area under the thermal curve is not known with accuracy.
Abstract: Some particular methods of collecting and treating DSC data for the determination of kinetic parameters in thermal decompositions of solids are suggested. These are mainly concerned with an extrapolation method to avoid the effect of the sample mass; with an approximate method to obtain the activation energy and the exponent of the decay-law for runs at constant temperature in which the total area under the thermal curve is not known with accuracy; and with a method to ascertain whether a particular decomposition takes place by a single mechanism or by a sequence of different mechanisms.
29 citations
Journal Article•
TL;DR: In this paper, a study of low-lying states in the self-conjugate nucleus 48Cr has been performed with the reaction 40Ca(10B, pnγ)48Cr.
TL;DR: In the guinea‐pig heart histamine appears to be taken up, stored and metabolized in at least two pools, one of which is linked to the mast cells, so reflecting the regional distribution of endogenous histamine and mast cell numbers.
Abstract: 1. The uptake and metabolism of histamine by the guinea-pig heart and by the isolated electrically driven guinea-pig left atria was studied with both labelled and unlabelled histamine.2. Histamine uptake took place against a concentration gradient and, at low concentrations, this was blocked by hypoxia plus glucose deprivation or by a toxic dose of ouabain.3. The histamine taken up was retained by cardiac tissues and mainly metabolized into methyl-histamine and other metabolites. The uptake and metabolism of histamine was higher in atria than in ventricles thus reflecting the regional distribution of endogenous histamine and mast cell numbers.4. The uptake and metabolism of histamine were greatly reduced in hearts which had been depleted of mast cells, by combining cardiac anaphylaxis and (+)-tubocurarine (1 mg/ml), but pretreatment of guinea-pigs with 6-hydroxy-dopamine failed to affect uptake of total radioactivity in the isolated left atria.5. In the guinea-pig heart histamine appears to be taken up, stored and metabolized in at least two pools, one of which is linked to the mast cells.
TL;DR: Reexamination of the 1958 skull of the late Miocene Oreopithecus bambolii revealed a cranial anatomy different from that widely accepted for this taxon.
Abstract: Reexamination of the 1958 skull of the late Miocene Oreopithecus bambolii revealed a cranial anatomy different from that widely accepted for this taxon. There is a sagittal crest, a high nuchal crest, a large gonial angle, and α high, rather vertical, occiput. This catarrhine was not a very large brained primate compared to known advanced hominoids.
TL;DR: A 57‐year‐old woman presented with symmetrical reddish‐brown plaques on the entire skin, especially the extremities, which differed in size and shape, and their consistency ranged from soft to tight‐elastic, to hard in the older lesions.
Abstract: A 57-year-old woman presented with symmetrical reddish-brown plaques on the entire skin, especially the extremities. The lesions differed in size and shape, and their consistency ranged from soft to tight-elastic, to hard in the older lesions (Fig. 1). The forearms and the dorsae of the hands and feet were covered with confluent plaques; some of these had an isolated nodular lesion on top. The lesions on the arms were papular-nodular, arranged in rows to form “cords” with “pseudokeloid” appearance (Fig. 2). On the face, around the cheeks, the wings of the nose, and the ears, there were purplish nodular lesions and plaques.
The lesions first appeared 14 years ago in the winter as lentile-sized, slightly reddish papules on both legs. These lesions disappeared spontaneously during the summer and returned the following winter. For 4 years the lesions followed this pattern of appearing and disappearing, leaving residual pigmentation. The patient reported that at each recurrence the lesions were larger and darker. Subsequently, the lesions had become permanent without any improvement during the summer and had also spread to the upper limbs and trunk. For the past 4 years the patient has had arthralgia of the large joints, swelling of the lower extremities, burning and pain in the lesions themselves. These symptoms became more evident in the evening and after exposure to cold.
A biopsy specimen of a recent lesion showed a dermal perivascular infiltrate comprised mainly of neutrophilic granulocytes and histiocytes and a few eosinophils. The vessels appeared dilated with swelling of the endothelial cells (Fig. 3). In and around the vessel walls an eosinophilic deposit of fibrinoid material was noted.
Electronmicroscopic examination revealed macrophages with secondary lysosomes containing electrondense, osmiophilic, probably lipid material, in the perivascular infiltrate. lnterdigitate cells, juxtaposed with the lymphocytes among the infiltrate cells were also seen (Fig. 4).
Direct immunofluorescence (DIF) revealed linear IgA deposits at the dermoepidermal junction. Direct immunofluorescence on healthy perilesional skin after histamine injection1 showed IgA, C3, and fibrinogen at the perivascular level in the superficial dermis and at the dermoepidermal junction with granular appearance.
Cutaneous fibrinolytic activity (CFA) evaluated with Todd's autohistographic method1, modified by Lotti et al.2, was reduced by 80% compared to that of healthy subjects.
Findings of other laboratory tests are listed in Table 1. Relevant investigations showed a decrease in fibrinogen, positive protein C and RA tests, the presence of cryoglobulin, and an increase in serum |gA.| Circulating immune complexes were detected and glucose-6-phosphate-dehydrogenase (GG-PD) was slightly low. The tests of clotting function showed some changes due to increased platelet aggregability from exogenous adenosine diphosphate (ADP), a slight reduc-tion in fibrinogenemia due to the presence of D-dimers and other products of fibrinogen degradation, suggesting a state of chronic intravascular coagulation.
Treatment was begun with diaminodiphenylsulfone (50 mg/day), which was suspended because of adverse reac-tions (headache and nausea) and was replaced by clofa-zimine (starting dose 200 mg/day). Improvement in the sub-jective symptoms and healing of many lesions with residual pigmentation was noted.
TL;DR: In this article, the meson exchange contributions to the n-p radiative capture matrix element are nearly independent from the nucleon-nucleon potential model, and the resulting interaction effect, including the N 33 ∗ contribution calculated by Stranahan, is ∼ 9%.
TL;DR: In this article, the chromatographic behavior of thirty primary aliphatic amines on Dowex 50 X4 (NA+ and H+), sodium carboxymethylcellulose and Rexyn 102 (Na+) thin layers has been studied using HCl, buffer and salt solutions as eluents.
01 Jan 1973
TL;DR: In this article, a non-stationary Markov chain on a countable state space is considered and the transition probabilities are assumed to be continuous in ( s, t ) uniformly in the state space.
Abstract: We shall consider a non-stationary Markov chain on a countable state space E . The transition probabilities { P ( s , t ), 0 ≤ s ≤ t t 0 ≤ ∞} are assumed to be continuous in ( s , t ) uniformly in the state i e E .
TL;DR: In this paper, a comparison of median sizes of individual grain types and total samples yielded significant vertical and horizontal sorting trends, which allowed apparently unrelated samples from different cores to be grouped into proximal and distal parts of one turbidite type.
Abstract: Through an analysis of their coarse-grain composition (>63 μm), pumice-rich sandy layers from deep sea cores were identified as shelf-derived turbidites rather than deposits due to ash rain or drifting pumice. A comparison of median sizes of individual grain types and total samples yielded significant vertical and horizontal sorting trends, which allowed apparently unrelated samples from different cores to be grouped into proximal and distal parts of one turbidite type. A discrimination of samples belonging to unrelated turbidite layers was also possible. In addition, whatever the grain size, planktonic molluscs and foraminifera have Md-diameters 1·1–2·75 times larger than those of pumice. Weathered shallow-water skeletals have Md-diameters approximately equal to pumice, whereas those of augite and hornblende are 1·25–2·3 times smaller. This results in a different proportion of components in proximal and distal turbidite samples. The Md-values of planktonic foraminifera reach their upper natural limit at 250–350 μm.
TL;DR: In this paper, the electrochemical oxidation of orthanilic, metanilic and sulfanilic acids has been investigated on platinum and carbon paste electrodes with periodical renewal of the diffusion layer.
TL;DR: A correlation between the above fluorescence change and the photochemical behaviour of anthracene was found in this paper, where two different products formed under irradiation of Anthracene were isolated and recognized as anthracenes dimer and anthraquinone.
Abstract: Fluorescence changing of anthracene crystals in air, O2, N2, recorded at room temperature is reported. Two different products formed under irradiation of anthracene were isolated and recognized as anthracene dimer and anthraquinone. A correlation between the above fluorescence change and the photochemical behaviour of anthracene was found.
TL;DR: Cell-coat material from Polyoma and Rous sarcoma virus-transformed cell lines failed to show significant differences in chromatographic properties and in sugar and amino acid composition, and minor but reproducible differences were found in the polyacrylamide electrophoresis migration patterns, when comparing glucosamine-labelled materials.
TL;DR: It is suggested that lysosomal enzymes play a role in asphyctic damage to skeletal muscle through changes in activity of soluble and particle-bound enzymes in male rabbits.
TL;DR: In this article, the chromatographic behavior of 16 metal ions, including Sr, on thin layers of sodium carboxymethylcellulose and Dowex 50X4(Na/sup +/) was investigated.
TL;DR: Octanoate and oleate inhibited the isocitrate lyase activity, similarly to cycloheximide, chloramphenicol, and actinomycin, inhibitors of protein biosynthesis.
Abstract: The changes of isocitrate lyase levels with respect to the catabolism of triglycerides have been studied during the germination of Pinus pinea seeds. We studied the effects of octanoate, oleate, and inhibitors of protein synthesis on isocitrate lyase during germination. Pyruvate kinase, glucose-6-P-dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase were also assayed. Octanoate and oleate inhibited the isocitrate lyase activity, similarly to cycloheximide, chloramphenicol, and actinomycin, inhibitors of protein biosynthesis. This inhibitory effect is not specific but is strikingly evident with isocitrate lyase. This inhibition was not proportional to the concentration but was proportional to the chain length of oleate and octanoate.
TL;DR: In the atrium, very low concentrations of burimamide were found capable ofblocking histamine metabolism, even at concentrations far below the dose range capable of blocking the positive chronotropic effect of histamine in the isolated atrium.
Abstract: Burimamide, an H2-receptor blocking agent, has been shown capable of blocking the uptake and metabolism of [14C]-histamine, both in the guinea-pig isolated atrium and in murine neoplastic mast cells. This occurs even at concentrations far below the dose range capable of blocking the positive chronotropic effect of histamine in the isolated atrium. In the atrium, very low concentrations of burimamide were found capable of blocking histamine metabolism.
TL;DR: In this paper, it is known that polyamine ligands form very stable complexes with transition metal ions and that the stability is measured by the formation constants of these complexes and it is made up of two main contributions: enthalpic (ΔH°) and entropic ( ΔS°)
TL;DR: In this article, two anti-Ag sera were described which reveal a new specificity: Ag(h), and the dominant mode of inheritence of this new factor as well as its genetic relationship to the Ag(a1,c,d,g,t,x,y,z) system is demonstrated.
Abstract: . Two anti-Ag sera were described which reveal a new specificity: Ag(h). The dominant mode of inheritence of this new factor as well as its genetic relationship to the Ag(a1,c,d,g,t,x,y,z) system is demonstrated.