Showing papers by "University of Barcelona published in 1984"
TL;DR: It is suggested that decompensated cirrhotics with depressed reticuloendothelial system phagocytic activity are at great risk to acquire bacteremia, and that reticulendothetic activity has prognostic value in cirrhosis.
443 citations
TL;DR: BM histologic pattern appears to be a better single prognostic parameter than any one of the variables employed in current clinical staging systems, and a combined clinicopathologic system incorporating the BM pattern is presented.
302 citations
TL;DR: The results obtained demonstrate that blastema formation in planarians occurs through mechanisms somewhat different to those shown to occur in the classical epimorphic models of regeneration, and suggest that planarian regeneration could represent an intermediate stage between morphallactic and epIMorphic modalities of regeneration.
Abstract: Mitotic activity during regeneration in the planarian Dugesia (G) tigrina shows a biphasic pattern, with a first maximum at 4-12 h, a second and higher maximum at 2-4 days, and a relative minimum in between. The first peak is mainly due to pre-existing G2 cells entering mitosis shortly after cutting, whereas the second maximum is due to cells that divide after going through the S period from the onset of regeneration. From a spatial point of view, the highest mitotic values are found in stump (postblastema) regions near the wound (0-300 micron), though regions far from it also show increased mitotic values but always lower overall values. As regeneration continues the postblastema maximum shifts slightly to more proximal regions. In contrast, no mitosis has been found within the blastema, even though the number of blastema cells increases steadily during regeneration. The results suggest that blastema in planarians forms through an early accumulation of undifferentiated cells from the stump to the base of blastema. The results obtained demonstrate that blastema formation in planarians occurs through mechanisms somewhat different to those shown to occur in the classical epimorphic models of regeneration (Annelida, Insecta, Amphibia), and suggest that planarian regeneration could represent an intermediate stage between morphallactic and epimorphic modalities of regeneration.
254 citations
TL;DR: By line digraph iterations it is possible to construct digraphs with a number of vertices larger than (d2- l)/d2times the (nonattainable) Moore bound, which solves the (d, k) digraph problem for k = 2.
Abstract: This paper studies the behavior of the diameter and the average distance between vertices of the line digraph of a given digraph. The results obtained are then applied to the so-called (d, k) digraph problem, that is, to maximize the number of vertices in a digraph of maximum out-degree d and diameter k. By line digraph iterations it is possible to construct digraphs with a number of vertices larger than (d2- l)/d2times the (nonattainable) Moore bound. In particular, this solves the (d, k) digraph problem for k = 2. Also, the line digraph technique provides us with a simple local routing algorithm for the corresponding networks.
215 citations
TL;DR: The present trial compared the effectiveness and complications of intravenous somatostatin and vasopressin in treatment of variceal bleeding to find out if these drugs should be given as continuous intravenous infusions.
211 citations
TL;DR: In this article, it was shown that during the Palaeogene Alpine compression, three units were differentiated in the studied area (south of the Ebro Basin): the Catalan Coastal Range, dominated by NE-SW major basement faults with a sinistral movement; The Iberian Range, where the important basement faults have a NW-SE direction and a reverse movement (often with a dextral component); the Linking Zone, between these two ranges, where an E-W dominant structural direction is marked by an array of folds and thrusts (with a northward
Abstract: During the Palaeogene Alpine compression three units were differentiated in the studied area (south of the Ebro Basin): the Catalan Coastal Range, dominated by NE–SW major basement faults with a sinistral movement; The Iberian Range, where the important basement faults have a NW–SE direction and a reverse movement (often with a dextral component); the Linking Zone, between these two ranges, where an E–W dominant structural direction is marked by an array of folds and thrusts (with a northward vergence) in the Mesozoic cover.From the analysis of both these major structures and the small-scale structures, it can be deduced that the compression in the studied area has evolved from a NW–SE direction (lower-middle Eocene) to a N–S direction and to a NE–SW one (uppermost Oligocene). The major structures are due to the N–S compression. Later, the stress-field progressively changed to a distensive regime.We suggest a relation between the compressive phases and the displacement direction of the Iberian Plate with reference to the European Plate.
147 citations
TL;DR: Significant and inverse circadian rhythms are demonstrated in glucose and plasma insulin in fish fed a natural diet and the differences in the compositions of the diets could be responsible for the lack of circadian rhythms in fish feeding on a commercial diet.
129 citations
TL;DR: The results suggest that renal PGE2 plays an important role in the maintenance of water excretion in cirrhosis with ascites, and that impaired ability to dilute the urine in Cirrhosis may be a consequence of the simultaneous occurrence of impaired renal hemodynamics, nonostomic hypersecretion of ADH, and reduced renal production of PGE1.
125 citations
TL;DR: In this article, the Callan-Symanzikγ-and β-functions are calculated analytically for Q.E.D. in the limit of a large number of leptons up to terms of order 1/NαπF inclusive, and closed analytic expressions for the coefficients of these terms in their series expansion in powers of K ≡αNαNF/π.
Abstract: The Callan-Symanzikγ- andβ-functions are calculated analytically for Q.E.D. in the limit of a large number of leptons (N
F→∞) up to terms of order 1/N
F inclusive. We give closed analytic expressions for the coefficients of these terms in their series expansion in powers ofK ≡αN
F/π. We have been able to sum these series and to obtain some striking results.
122 citations
TL;DR: The clinical and physical signs appearing after the intoxication include irregular respiration, diarrhea, ataxia and paralysis of the hind legs, which suggests a quick elimination of vanadium.
120 citations
TL;DR: In this paper, quantum mechanics calculations have been applied to different linear chain diols, diamines and aliphatic amino alcohols and the corresponding structures have been optimized, and the energies and coefficients of their molecular orbitals have been calculated, using the semi-empirical method MINDO/3.
TL;DR: The results suggest that the presence of cancer in the large bowel directly influences methane production, and in the group of diseases with a high risk of malignancy, the prevalence of methane-producing individuals was significantly higher than in the healthy population and in patients with benign diseases of the colon.
01 Jan 1984
TL;DR: The existence of a cancer dans le colon influence directement the production of methane, and the prevalence of such cancers is significativement plus elevee that dans la population normale and chez les malades avec des maladies benignes du colon as discussed by the authors.
Abstract: L'existence d'un cancer dans le colon influence directement la production de methane. Dans le groupe des maladies a haut risque de cancer, la prevalence des sujets producteurs de methane est significativement plus elevee que dans la population normale et chez les malades avec des maladies benignes du colon
TL;DR: In this paper, carboxylic acids, aryl or alkyl azides, and Ph3P in refluxing benzene (hexane, toluene) afford amides in good yields.
TL;DR: The authors consider this papillary‐cystic neoplasm of the pancreas as having an acinar origin because in the cells of one of the patients, the presence of abundant rough endoplasmatic reticulum with formation of annulate lamellae and a few prezymogen granules is observed.
Abstract: Two cases of papillary-cystic neoplasm of the pancreas are reported in women aged 22 and 23 years. The patient in the first case presented with acute abdominal pain and hemoperitoneum. This form of presentation has not been previously reported. This type of pancreatic tumor is very rare, exclusively affecting young women, and has a good prognosis despite its various histologic features, which suggest a malignant appearance. The authors consider this neoplasm as having an acinar origin because in the cells of one of the patients we observed ultrastructurally the presence of abundant rough endoplasmatic reticulum with formation of annulate lamellae and a few prezymogen granules.
TL;DR: In this paper, the optimal conditions to acquire gel-phase 13C-NMR spectra of copoly(styrene-l%-divinylbenzene) has been determined.
TL;DR: In this article, the authors revisan algunos avances conseguidos durante los ultimos anos in el estudio de la interaccion alumno-alumno and de su influencia sobre el nivel de rendimiento y los resultados del aprendizaje.
Abstract: ResumenLa influencia sobre el proceso de socializacion de las relaciones que se establecen entre los alumnos, asi como su importancia para el logro de los objetivos socio-afectivos, es un hecho reconocido desde hace tiempo. En cambio, los efectos de estas relaciones sobre el aprendizaje escolar es un aspecto mucho mas discutido, tal vez como consecuencia del modelo pedagogico imperante que contempla al profesor como el unico agente educativo. En el articulo se revisan algunos avances conseguidos durante los ultimos anos en el estudio de la interaccion alumno-alumno y de su influencia sobre el nivel de rendimiento y los resultados del aprendizaje. Se presta especial atencion a los resultados de las investigaciones que ocuparon las diferentes formas de organizacion social de las actividades escolares—cooperacion, competicion e individualismo—, asi como a algunos tipos de modalidades interactivas—relacion tutorial, confrontacion de puntos de vista divergentes, controversias conceptuales y trabajo grupal coop...
TL;DR: In this article, the glass formation and crystallization of liquid-quenched (GeSe2)100y/(Sb2Te3) alloys was investigated by means of differential scanning calorimetry, X-ray diffraction and optical and scanning electron microscopy.
Abstract: The glass formation and crystallization of liquid-quenched (GeSe2)100-y
/(Sb2Te3)
y
alloys was investigated by means of differential scanning calorimetry, X-ray diffraction and optical and scanning electron microscopy. By water quenching glasses are obtained from compositions in the range 5≲y≲30. Qualitative parametrization of glass-forming tendency gives, as best glass formers, alloys with y≅20. Crystallization on heating proceeds in one stage for glasses withy≲20 and in two stages for those with greater Sb2Te3 content. For compositions lying in the GeSe2 primary crystallization region crystals appear preferentially at the surface of the sample, but for the other compositions (24≲y≲30) the crystals emerge in the bulk and often develop in spherulitic or axialitic form.
TL;DR: A new surgical technique, particularly effective in patients with megatrigone, has been used in 38 children and adults with excellent results, and involves a single stitch that imbricates the trigone, effectively lengthening the intramural segment of terminal ureter.
TL;DR: The analysis of the mixotrophic system shows that light energy, dissipated during autotrophic growth, is used underMixotrophic conditions, and the increase in photosynthetic efficiency can be calculated as ca.
Abstract: Chlorella sp. strain VJ79 was isolated from a total heterotrophic count of a wastewater collector. It grows autotrophically, heterotrophically, and mixotrophically on a variety of organic substrates. Glucose and serine promote a mixotrophic growth from which the yield is higher than the sum of autotrophic and heterotrophic yields, but serine assimilation requires light. The interaction of glucose and light was studied in proliferating and nonproliferating cells by respirometry (IRGA and Warburg) and growth experiments. Glucose inhibits the photosynthetic CO2 fixation ten-fold and modifies the pigmentary system as it does in heterotrophic cultures. Light inhibits glucose uptake and assimilation, but under mixotrophic conditions maximal utilization of glucose is obtained. Mutants defective in autotrophic growth were isolated by mutagenesis with nitrosoguanidine. They show a degenerated pigmentary system and a mixotrophic growth yield equal to that of the heterotrophic growth. The analysis of the mixotrophic system shows that light energy, dissipated during autotrophic growth, is used under mixotrophic conditions. From the increase in growth, the increase in photosynthetic efficiency can be calculated as ca. sixfold.
TL;DR: In this paper, the near-IR transmission spectra of vacuum-evaporated CdTe thin films grown at different temperatures and rates are studied, as well as the effect of thermal annealing on the spectra.
TL;DR: In this article, a set of charged species arising mainly from protonation or deprotonation of hydrocarbons, alcohols, ethers, carboxylic acids, amines, imines, and nitriles has been studied by means of the semi-consistent field (SCF) molecular orbital (MO) MNDO method.
Abstract: A large set of charged species arising mainly from protonation or deprotonation of hydrocarbons, alcohols, ethers, carboxylic acids, amines, imines, and nitriles has been studied by means of the semiempirical self‐consistent‐field (SCF) molecular orbital (MO) MNDO method. From the calculated heats of formation of such charged species and those of neutral molecules, MNDO‐estimated proton affinities have been obtained and the results compared with experimental gas‐phase proton affinities. If the small size anions and acetylides, for which the method predicts heats of formation too large, are ruled out, the mean absolute error in calculated proton affinities is ca. 7 kcal/mol for hydrocarbons (22 acid‐base pairs) and ca. 8 kcal/mol for oxygen‐containing compounds (25 acid‐base pairs). For nitrogen‐containing molecules it is necessary to discard, in addition, the values corresponding to the protonation of alkylamines and imines in order to achieve a reasonable mean absolute error of 7–8 kcal/mol.
TL;DR: A non-linear regression program, written in BASIC, is described, which uses the Marquardt 's algorithm as modified by Reich et al.
Abstract: A non-linear regression program, written in BASIC , is describe. The program uses the Marquardt's algorithm as modified by Reich et al. ( Eur. J. Biochem. , 26 (1972) pp.368–379). The user only supplies the expression to fit, since the program uses numerical differentiation. It is possible to fit models of 1 substrate, 2 substrates, 1 substrates and 1 inhibitor, and 2 substrates and 1 inhibitor. Likewise, several weighting patterns, as well as a simple or robust regression, can be selected.
TL;DR: Aerobic degradation of an Arabian light crude oil residue by bacterial strains ( Pseudomonas spp. ), isolated from tanker ballast waters, revealed that degradation of alkyl aromatics, namely, alkylnaphthalenes, depende on the position, number and type of the substituents as mentioned in this paper.
TL;DR: In this article, the cyclometallation of p-RC6H4CHNCH2C6H2, (R = H, Cl, NO2) by PdX2 (X = Cl, AcO) has been studied.
TL;DR: In this article, a detailed scattering model, based on the continuous slowing down and the Born approximations, is shown to give results in good accordance with experiments when used in conjunction with the Monte Carlo method, and Relativistic elastic and inelastic cross-sections adopted are derived from an analytical fit to the Dirac-Hartree-Fock-Slater atomic density with Wigner-Seitz boundary conditions.
Abstract: A detailed scattering model, based on the continuous slowing down and the Born approximations, is shown to give results in good accordance with experiments when used in conjunction with the Monte Carlo method. Relativistic elastic and inelastic cross-sections adopted are derived from an analytical fit to the Dirac-Hartree-Fock-Slater atomic density with Wigner-Seitz boundary conditions. Random tracks are simulated in a completely analytical way; this fact largely reduces the complexity of the Monte Carlo procedure.
01 Jan 1984-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, a theory of conversion electron Mossbauer spectroscopy including second order effects, i.e., secondary electron emission, and detection coincidence corrections has been derived, which is applicable to surface films containing any number of distinct layers.
Abstract: A theory of conversion electron Mossbauer spectroscopy (CEMS) including second order effects, i.e. secondary electron emission, and detection coincidence corrections has been derived. The theory is applicable to surface films containing any number of distinct layers. The partial spectra are given in terms of analytical functions of the Mossbauer parameters and the physical characteristics of each layer in the sample. Numerical results are compared to available experimental data.
TL;DR: In this article, el segmento estudiado es el industrial, i.e., la evolucion of una parte (aproximadamente un sexto) of the producto interior bruto de Es- pana desde mediados del siglo xix hasta la actualidad.
Abstract: Una de las diversas posibilidades que se me ofrecen para describir el con tenido de las paginas que siguen, quiza la mas fria y aseptica, pero tambien la mas exacta, consiste en decir que cuantifica la evolucion de una parte —en la actualidad, aproximadamente un sexto— del producto interior bruto de Es pana desde mediados del siglo xix hasta la actualidad. El segmento estudiado es el industrial. No todo, pero si un conjunto de
01 Jun 1984-Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science
TL;DR: In this article, the dissolution of synthetic samples of zinc ferrite in aqueous hydrochloric acid is stoichiometric and the rate appears to be controlled by a chemical reaction on the solid surface.
Abstract: The dissolution of synthetic samples of zinc ferrite in aqueous hydrochloric acid is stoichiometric The rate appears to be controlled by a chemical reaction on the solid surface, and dependence of the dissolution rate on hydrochloric acid activity is of the first order Activation energy of 83 kJ mol-1 was found Zinc ferrite leaching is a slow solubilization process in the hydrochloric acid treatment of dead-roasted Iberian pyrite ashes The most favorable conditions are 05-1 M HC1 at 90 to 100 ‡C, when preferential solubilization of the spinel phases takes place on the hematitic matrix Extensive extraction of zinc (~90 pct of total zinc) in one to two hours and low solubilization of iron (~8 pet of total iron) results under these conditions