showing 36 of ~574560 from 574555 documents
Estudio de la alimentación de las rapaces nocturnas aplicado a la interpretación del registro faunístico arqueológico
1991
Effects of isoxaben on sensitive and tolerant plant cell cultures .I. Metabolic fate of isoxaben
1991
International audience
The household location in multicenter urban spaces
1991
In multicenter urban spaces, the household location problem is to find an optimal location taking into account the locations of several economic centers.In this article, we show that the usual model, maximizing a residential utility under a budget spatial constraint, can’t give a satisfactory solution.So, we construct a fuzzy spatial model, including imprecision in consumer’s behavior. This model allows us to find an optimal location in a multicenter urban setting. Then, an empirical study illustrates the performances of the fuzzy model.
Photoelectrochemical study of passive films on stainless steel in neutral solutions
1991
Abstract Passive films formed on AISI 304 stainless steel in neutral solutions are studied using photoelectrochemical technique. Photocurrents were investigated as a function of the wavelength of the incident light, the electrode potential and the time. The results of the measurements together with capacity measurements indicate that the passive film on AISI 304 shows characteristics of a highly doped amorphous or highly disordered n-type semiconductor. The potential dependence of the optical gap values and of the photocurrent transients can be interpreted assuming that the passive film is an iron-chromium oxide solid solution.
Model compound synthesis for the structure determination of new unknown planar aromatic compounds originating from pulp mill
1991
Abstract Several model compounds have been synthesized for verification of the structures of new unknown planar aromatic compounds (UPACs) observed in high-resolution gas chromatography/low-resolution mass spectrometry analyses of the polychlorodibenzodioxins (PCDDs) and polychlorodibenzofurans (PCDFs) in pulp mill products, effluents, sediments and mussels. The mass spectra of synthetic alkyl polychlorodibenzofurans (C6-PCDFs) were different, but those of alkyl polychlorobibenzyls (C5-PCBBs) were very similar compared to the spectra of UPACs.
Sonographie von Urachusanomalien im Kindesalter
1991
The sonographic appearances of urachal anomalies are illustrated by six patients with persistent urachus (n = 1), infected persistent urachus (n = 1), urachal sinus (n = 1), infected urachal cyst (n = 2) and urachal diverticulum (n = 1). The anomalies were diagnosed sonographically in every case. Symptomatic patients were treated surgically.
Opioid Inhibition of Oxytocin Release, but not Autoinhibition of Dopamine Release May Involve Activation of Potassium (K+) Channels
1991
ABSTRACT Release of oxytocin (Ox) or dopamine (DA) from the isolated neural lobes or neurointermediate lobes, respectively, was evoked by high K + (30 or 45 mM). Naloxone (1-10 μmol/l) which largely enhances the impulse-induced release of Ox had no effect on Ox release evoked by 30 or 45 mM K + . In the presence of 10 mM tetraethylammonium (TEA), Ox release evoked by 30 or 45 mM K + was increased 2-3fold; nevertheless, naloxone caused a further 2-3fold increase. Barium (500 μM) and quinidine (300 μM) antagonized the effect of naloxone observed in the presence of TEA. (-)-Sulpiride (10 μM) enhanced the release of DA evoked by 30 and 45 mM K + by 94 % and 19 %, respectively. TEA enhanced the …
Hauptthema: Neue Infektionskrankheiten
1991
Die Ulcuskrankheit entsteht aus einer Imbalanz mucosaschadigender und mucosaschutzender Prinzipien. Dennoch dominiert der Faktor Saure mit Recht seit Dekaden die pathophysiologischen Konzepte und therapeutischen Strategien. So ist Saure einerseits die einzig bislang bekannte unabdingbare Voraussetzung fur die Entstehung jedes Ulcus, zum anderen heilen praktisch alle Ulcera unter einer sauresekretionshemmenden oder -neutralisierenden Behandlung ab. Da aber bis heute die Atiologie und Pathogenese der Ulcuskrankheit, mit Ausnahme beim Zollinger-Ellison-Syndrom und den durch nichtsteroidale Antirheumatika bedingten Ulcera, weitgehend ungeklart ist und ihr Spontanverlauf durch medikamentose Inte…
Un 'osculatori' i dues plaques de cinturó de la comarca dels Ports
1991
En este artículo se estudian tres bronces encontrados en diferentes localidades de la comarca de els Ports, situada en el extremo NO del País Valenciano. Se trata de uno de los llamados 'osculatorios' procedente de El Portell y de una placa de cinturón procedente de Bel -ambos de la antigua colección de J.J. Senent y publicados por H. Zeiss en 1934- y de una placa incompleta de cinturón del mismo tipo encontrada recientemente en Cinctorres.
Deconvolution of XPS spectra
1991
The resolution of XPS spectra is limited mainly by instrumental parameters like the spectral line width of the exciting X-ray source and the finite energy resolution of the electron analyzer. If the line broadening functions resulting from the instrumental setup can be estimated and expressed by a spectrometer function, a mathematical recalculation of the intrinsic signal is possible by deconvolution. With the method presented in this paper, a resolution enhancement by a factor of 3 can be obtained. Measured spectra of physically correlated spin orbit doublets have been deconvoluted, and it is shown, that the intensity ratios and the positions are comparable with results obtained by highly …
3.3 Glucose levels in microregions of multicellular EMT6/Ro tumor spheroids
1991
Mujeres y espiritualidad: las beatas valencianas del siglo XVII
1991
Este artículo es un resumen del capítulo «El mundo enigmático de las beatas», incluido en mi tesis doctoral inédita «La Espiritualidad Valenciana. El lluminismo en los siglos XVI y XVII», dirigida por el Prof. Antonio Mestre y leída en la Universidad de Valencia el 31 de enero de 1989. En Valencia, a lo largo del siglo XVI, existían ejemplos de mujeres que, bien en sus casas solas o en comunidad con otras, emparedadas o no, dedicaban el resto de sus días a la religión. A estas conocemos con el nombre de beatas, fenómeno social de indudable interés en la espiritualidad valenciana del siglo XVII.
The effect of time on physiological changes in eel Anguilla anguilla, induced by lindane.
1991
Abstract 1. 1. Eel were exposed to a sublethal concentration of lindane (0.335 ppm) for 6, 12, 24, 48, 72 and 96 hr. 2. 2. Concentrations of glycogen, glucose, lactate, pyruvate and lipids were determined in gill tissue after lindane exposure. 3. 3. Gill glycogen descreased and glucose levels increased at 6 hr of treatment, lactate and pyruvate concentration increased between 6 and 48 hr. Total lipid values decreased between 6 and 24 hr; thereafter, the levels increased up to 72 hr of exposure. 4. 4. Clear changes were found in all parameters tested in gill tissues. The observed effects of lindane on metabolism in fish are discussed in relation to acute stress syndrome.
Estilo de una Domus romana de Valentia y de los niveles que la amortizaban
1991
Numerical and experimental analysis of load capacity of pressure vessels for large deformations
1991
Abstract A method of theoretical and experimental investigations of large deformations and load capacity of pressure vessels has been proposed. Algorithms and programs for numerical analysis (with the finite element method) of spatial stress and strain state and load capacity have been worked out according to the Prandtl-Reuss theory of plastic flow. Loading in the vessel was realized in an incremental way. The loading process was continued up to the moment when the maximum loading was obtained (i.e. the moment when state of equilibrium of the vessel was not possible). It has been found that in thin-walled circular vessels with rigid bottoms, when a ratio of length to their diameter is less…
Relationship between mutagenicity and DNA adduct formation in mammalian cells for fjord- and bay-region diol-epoxides of polycyclic aromatic hydrocar…
1991
Abstract Chinese hamster V79 cells were treated with the anti- and syn-diastereomers of the bay- or fjord-region diol-epoxides of four polycyclic aromatic hydrocarbons, namely benzo[a]pyrene (BP), benzo[c]chrysene (BcC), benzo[g]chrysene (BgC) and benzo[c]phenanthrene (BcPh). The frequency of induction of 6-thioguanine-resistant mutations was determined, and the extent of formation of DNA adducts was measured by 32P-postlabelling. When expressed as mutation frequency per nanomoles compound per millilitre incubation medium, this group of chemicals expressed a 160-fold range in potency. In agreement with previous experimental studies, the anti-diol-epoxide of BcC was highly mutagenic, inducin…
Mixed-type circuits with distributed and lumped parameters as correct models for integrated structures
1991
The technology of integrated circuits imposes upon their designers the need to deal with structures with distributed parameters. Figure 4.1 shows a schematic diagram of part of a digital integrated chip, consisting of an n MOS transistor with gate (G), drain (D) and source (S) as terminals, and its thin-film connection with the rest of the chip. This on-chip connection can be made by metals (Al, W), polycristaline silicon (polysilicon) or metal suicides (WSi 2 ). Alternative materials to oxide-passivated silicon substrates are saphire and gallium arsenide (Saraswat and Mohammadi [1982], Yuan et al. [1982], Passlack et al. [1990]).
Synthesis of (−)-auricularic acid and its C-4 epimer the absolute configuration of auricularic acid
1991
Abstract A synthesis of (−)-auricularic acid (2a) starting from methyl (+)-13-oxo- podocarp-8(14)-en-19-oate (3a) and a synthesis of its C-4 epimer (2b) starting from methyl (+)-13-oxopodocarp-8(14)-en-18-oate (3b) are described. The absolute configuration of natural auricularic acid is stablished as (4R, 5S, 8S, 9R, 10S, 14S).
DNA Fingerprinting for the Protection of Endangered Species
1991
The main application of DNA fingerprinting is based on identity and paternity testing in man [6, 7]. In the last years it has also been increasingly used for zoological problems [2–5, 8, 10, 12, 13]. In this study DNA fingerprinting was applied for “forensics” in the field of protection of endangered species.
Acute dialysis: PMN-elastase as a new parameter for controlling individual anticoagulation with low molecular weight heparin (Fragmin).
1991
Despite the improvements in the development of dialyzer membranes with greater hemocompatibility, an activation of the coagulation system occurs when blood comes into contact with exogenous surfaces. The large number of heparin dosage regimens demonstrate the difficulty to adapt general therapeutic guidelines. Low molecular weight heparin (Fragmin®) was administered as a single bolus dose for anticoagulation during 58 acute dialyses. Anti-Xa-activity, the plasma levels of the lysosomal elastase of the polymorphnuclear granulocytes (“PMN-elastase”) and of the thrombin-antithrombin III-complex (TAT) were measured at hourly intervals. Therapeutic anti-Xa-levels did not show evidence of suffici…
Baltu filoloģija, 1: zinātniski informatīvi ziņojumi
1991
El valor del tiempo en la Universidad
1991
Alguns aspectes de l'estructura sintàctica de l'oració
1991
Quantitatif ou qualitatif ? Les incendiaires au 18e siècle
1991
International audience
Amelioration de l'efficacite des phytosanitaires : des techniques a preciser
1991
National audience
Characterization of blends of polypropylene with a semirigid liquid-crystal copolyester
1991
Abstract Blends with a liquid-crystal polymers (LCP) as one component show, in general, very interesting properties. Reduction of shear viscosity and improvement of mechanical properties are very remarkable. High melting temperatures and high costs of the LCP limit the use of these blends. A new class of thermotropic LCPs with flexible spaces, with relatively low melting temperatures, can overcome the first problem. In this work, rheological and mechanical properties of blends of polypropylene with low contents of this LCP are presented. Torque during extrusion and viscosity decrease with LCP content. Elastic modulus is remarkably increased when the LCP phase is oriented.
Albaida, villa y señorío: Administración municipal y oligarquía urbana en el siglo XVII
1991
La fabricazione di una fibula celtica
1991
International audience
Fractura-luxación de Galeazzi, con epifisiolisis cubital distal e interposición tendinosa.
1991
Una rara variante no descrita de la fractura-luxación de Galeazzi, con afectación de la epífisis del cúbito, cuya reducción estaba impedida por la interposición del tendón Extensor Carpi Ulnaris, (extensor cubital del carpo). Los autores presentan un caso y revisan la literatura, así como su solución quirúrgica y resultado obtenido. An unusual variant of Galeazzi's fracture-luxation involving the distal ulnar epiphysis, whos e reduction was impeded by the interposition of the Extensor Carpi Ulnaris (ECU) tendom. Presentation of a case and revision of the current literature.
Standardisation, Reference Materials and Comparative Measurements for Surface Area and Pore Characterisation
1991
Summary This paper reviews current activities to standardise measuring procedures for surface area and pore size determination. Comparative measurements at different laboratories using candidate reference materials revealed that surfaces of highly dispersed materials can be affected remarkably during storing and sample preparation. On account of the fractal nature of these materials, the results depend on the measuring methods. Reference materials of dispersed materials are offered by national and international standardisation administrations and by industrial distributers. The standardisation of measuring methods becomes more and more international (ISO, IUPAC). The survey includes tables …
‘Donne bibliche da Venanzio Fortunato ad un anonimo compilatore anglosassone’
1991
El imperativo del cambio o/y mejora tecnológica de la agricultura valenciana : análisis de los factores limitativos en los procesos de innovación y d…
1991
Breu semblança arqueològica de J. B. Porcar
1991
El pintor castellonense J. B. Porcar Ripollés desarrolló una importante actividad en el campo de la arqueología, centrada principalmente en el calco de pinturas rupestres.
Obstructive uropathy following aortofemoral graft surgery.
1991
Fifty patients who had undergone aorto-bifemoral bypass with a bifurcated Dacron graft for aortoiliac arteriosclerotic obliteration were examined with real-time sectorial ultrasound to screen for the presence of hydronephrosis. Hydronephrosis was detected in only 1 case. The low incidence of this complication in our cases may be due to the fact that all our patients were explored at least 1 year after surgery. Some may have developed hydronephrosis early, but this may have resolved spontaneously during the first year after the operation, thus remaining undiagnosed. Pathogenic mechanisms suggested for the development of hydronephrosis and therapeutic approaches are discussed. We conclude tha…
Separation of pesticides, related compounds, polychlorobiphenyls and other pollutants into four groups by silica‐gel microcolumn chromatography (appl…
1991
Multi‐residue analyses of pesticides and related compounds generally require clean‐up procedures for the elimination of interfering substances. An analytical procedure for use in the recovery and determination of pesticides and other pollutants in water samples is described, in which the purification of the extracts is improved by the separation of pesticides into four groups. The separation of pesticides by silica‐gel microcolumn chromatography is explained in detail. Copyright © 1991 John Wiley & Sons, Ltd
Moines et métallurgie dans la France médiévale
1991
International audience