showing 36 of ~574560 from 574555 documents
Prevención de enfermedades cardiovasculares en medicina de empresa : factores y parámetros de riesgo
1981
Struktur und Arbeitsweise von Giftinformationszentren
1981
In Deutschland gibt es z. Z. 17 Giftinformationszentren (Beratungsstellen bei Vergiftungen, s. tabellarischer Anhang S. 119–120). Sie wurden Ende der 60er Jahre von den obersten Gesundheitsbehorden der Lander ernannt. Zumeist handelt es sich um Medizinische Kliniken und in sechs Fallen um Kinder-kliniken.
The isotope shift of the radioactive Cd-isotopes (102?A?120) determined by on-line laserspectroscopy
1981
UV-spectrophotometric determination of tetrazene
1981
La production d'enseignement supérieur dans les établissements français
1981
National audience; En assimilant le secteur éducatif à une industrie et l’établissement scolaire à une firme, notre objectif est d'appréhender le mouvement interne de différentiation des diverses institutions françaises d’enseignement supérieur (les Unités d'enseignement et de recherche des universités, les Instituts universitaires de technologie et les différents types d'écoles). Une telle approche s'inscrit dans un cadre conceptuel qui vise à définir de manière multidimensionnelle la production d'enseignement des établissements au moyen des notices transversales et longitudinales de valeur ajoutée monétaire, de gain de qualité de vie, de diplômés, puis à retenir trois facteurs de producti…
Notas para el estudio de la escritura usual en Tortosa (primera mitad del siglo XIV)
1981
Etude numérique de contacts entre solides élastoplastiques
1981
International audience
Parameteridentifikation des geschlossenen Kreislaufmodells des Kurzzeitverhaltens mit Hilfe eines selbstanpassenden Referenzmodells unter Einbezug de…
1981
Die Grundaufgabe der Identifikation ist die Erkennung der unbekannten Struktur bzw. der unbekannten Parameter eines zu untersuchenden Systems.
Theorems of ascoli type involving measures of noncompactness
1981
H2-Antihistaminika, 7. Mitt. Synthese und H2-antihistaminische Wirkung N,N′-substituierter Thioharnstoffe, Cyanoguanidine und Dithiooxamide
1981
Es wurden N′-substituierte Thioharnstoffe, Cyanoguanidine und Dithiooxamide mit einem 5-Methyl-4-imidazolyl-methylthioethyl-Substituenten dargestellt und auf H2-antihistaminische Wirksamkeit untersucht. H2-Antihistaminics, VII: Synthesis and H2-Antihistaminic Activity of N,N′-Substituted Thioureas, Cyanoguanidines and Dithiooxamides N′-Substituted thioureas, cyanoguanidines and dithiooxamides with a 5-methyl-4-imidazolylmethylthioethyl substituent were prepared and tested for their H2-antihistaminic activity.
4,6-Dialkylierte Pyrimidinderivate
1981
β-Diketone 2, in denen mindestens 1 R einen unverzweigten aliphatischen Rest darstellt, reagieren mit Guanidincarbonsaureamid (1) bereits bei Raumtemperatur unter Bildung der entsprechenden 2-Ureidopyrimidine. 2,6-Dimethyl-3,5-heptandion (2a) und 2,2,6,6-Tetramethyl-3,5-heptandion (2b) setzen sich mit 1 jedoch erst bei erhohter Reaktionstemperatur um, und zwar unter Bildung der korrespondierenden 2-Aminopyrimidine 3a und 3b. Unter den 2-Ureidopyrimidinen finden sich Vertreter mit hypnotischer Wirksamkeit. 4,6-Dialkylated Pyrimidine Derivatives β-Diketones 2 in which at least one R group represents an unbranched aliphatic chain react with guanidinecarboxamide (1) at room temperature to form …
Regulation of Acetylcholine Synthesis and Release in the Isolated Heart
1981
In the two decades following Loewi’s work (8,9) on the frog heart several research groups tried to use the isolated heart preparation from higher vertebrates for further investigations on synthesis, release and inactivation of acetylcholine (ACh). However the results were discouraging because the overflow of ACh during vagal stimulation was near, or below, the limit of the assay.
A new apparatus for the study of avoidance conditioning in fishes
1981
An apparatus for the study of avoidance conditioning in fishes is described. The chamber is cylindrical in shape, with shocking electrodes placed above and below the animals, and response is defined as swimming a predetermined distance in either direction along a circumferential path. This apparatus has several advantages over the conventional shuttlebox: (1)There is little constraint on the direction of swimming; (2) the magnitude of response (swimming distance) required for avoidance can easily be varied over a wide range; and (3) variation in the effectiveness of shock with the position of the animal relative to the position of the electrodes is minimized. Some sample data obtained in a …
Identification of mechanical characteristics of a structure in composite material
1981
National audience
Interacción histórico-social y subjetividad en la obra de Wilhelm Dilthey
1981
El trabajo defiende la tesis según la cual la teoría diltheyana de las ciencias humanas surge de la pugna entre motivos románticos, que subrayan la historicidad del ser humano y la individualidad y peculiaridad de las formaciones histórico-sociales, y motivos positivistas: por un lado la insistencia en la uniformidad y en los elementos comunes a las diversas épocas históricas, en la explicación causal y las leyes en las que descansa; y por otro la tesis, que llega al positivismo a través del empirismo inglés y, en último término, del cartesianismo, según la cual todo conocimiento científico descansa en la inmediatez y certeza de los datos de conciencia. La pugna entre estos diversos motivos…
Yves Montand : la emoción de la memoria
1981
Periodicidad en grupos de dimensión cohomológica virtual finita
1981
Adducts of 1,4-diazabutadienes with group IIB metal halides
1981
Abstract The reactions of 1,4-diazabutadienes (or α-diimines) RNC(R′)C(R″)NR, DAB, (R = p -C 6 H 4 OMe, R′ = R″ = H, DAB I ; R = p -C 6 H 4 OMe,R′ = H, R″ = Me, DAB II ; R = p -C 6 H 4 OMe, R′= R″ = Me; DAB III ; R = CMe 3 , R′ = R″ = H, DAB IV ) with MX 2 M = Zn, Cd, Hg; X = CI, Br) yield in general 1/1 adducts. These species are assigned a monomeric configuration with a σ,σ′-N,N′, chelating DAB ligand for M = Zn, Hg, whereas the CdCl 2 adducts have polymeric structures with terminal and/or bridging chlorides. In the reactions of CdCl 2 with DAB I or DAB IV polymeric species [(CdCl 2 ) 2 (DAB)] x are obtained in which all chlorides are bridging. Spectrophotometric dissociation equilib…
Aportación al conocimiento de los pondrales ibéricas
1981
Lorcainid — Pharmakokinetik und Pharmakodynamik
1981
Nutzen und Notwendigkeit der heute praktizierten antiarrhythmischen Therapie sind umstritten. Gerade lebensbedrohliche Arrhythmien erweisen sich einer Standardtherapie mit konventionellen Antiarrhythmika gegenuber haufig als refraktar, wahrend eine erfolgreiche Therapie mit z. T. erheblichen Nebenwirkungen erkauft werden mus. Eine Verbesserung des Therapieerfolges erhofft man sich sowohl aus der Innovation neuer, wirksamerer und nebenwirkungsarmerer Antiarrhythmika, als auch aus der Anderung der therapeutischen Strategie (Ersatz der Standardtherapie durch eine individuell angepaste Dosierung).
Alkylation of RNA by Vinyl Chloride and Vinyl Bromide Metabolites in Vivo: Effect on Protein Biosynthesis
1981
Alkylation of DNA is viewed as representing the initial critical step in carcinogenesis induced by chemical substances. Vinyl chloride and vinyl bromide, compounds with proven carcinogenic potency toward the liver, are biotransformed to reactive metabolites which covalently bind to DNA (see Bolt et al. 1980). Furthermore, extensive covalent binding of metabolites of both vinyl chloride (Laib and Bolt 1977, 1978) and vinyl bromide (Ottenwalder et al. 1979) occurs to RNA of liver when rats are exposed to both vinyl halides. Defined products of alkylation are 1,N6-ethenoadenosine (Laib and Bolt 1777; Ottenwalder et al. 1979) and 3,N4-ethenocytidine (Laib and Bolt 1978; Ottenwalder et al. 1979)…
Effects of fatigue on isometric force- and relaxation-time characteristics in human muscle
1981
Effects of intermittent one leg isometric fatigue on maximal isometric force, force production, relaxation and blood lactate were studied using 29 male students as subjects. The relative changes of variables during fatigue and recovery were intercorrelated together with muscle structure variables, which were determined using needle biopsy technique. Maximal force decreased, force production and relaxation became slower and muscle lactate increased during fatigue. Change of maximal force, force production and lactate during fatigue as well as recovery of maximal force and lactate after fatigue were correlated significantly to muscle fiber distribution. Fatiguability of the force-time charact…
The Gas Scintillation Proportional Counter on EXOSAT
1981
The inclusion of a gas scintillation proportional counter (GSPC) within the EXOSAT payload complement significantly improves the spectroscopic capability of the mission. This broad-band medium energy spectrometer used in conjunction with the large area proportioni counter array (ME) should provide additional spectroscopic details on strong X-ray sources at photon energies above ~ 2 keV. The novel type of detector has an energy resolution at least a factor of two better than the ME experiment over a similar bandwidth (2 – 40 keV).
L'arbitrage révolutionnaire. Apogée et déclin d'une institution (1790-1806)
1981
Estudios descriptivo y predictivo de las evaluaciones del Bachillerato Unificado Polivalente y del Curso de Orientación Universitaria en el País Vale…
1981
Sleep Induction by Intranasal Application of Melatonin
1981
The sleep inducing potency of melatonin was tested in a double-blind study against placebo. The application form was a nasal spray with a 0.85% solution of melatonin in ethanol. 70% of the subjects fell asleep after treatment with the hormone.
Estudio de la tasa de retroceso de una vertiente mediterránea en los últimos 5000 años (Serra del Benicadell, sur del País Valenciano)
1981
Piezas con escotadura del paleolítico superior valenciano : (materiales del Museo de Prehistoria de Valencia) / por Valentín Villaverde Bonilla y Jos…
1981
Dos fueron los objetivos que nos propusimos al abordar este trabajo sobre el paleolítico superior valenciano: precisar morfológicamente los diferentes tipos de piezas con escotadura y delimitar si su evolución podía ser significativa, no ya de la tradicional división entre Solutrense Superior y Solútreo-Gravetiense, sino de la dinámica industrial de este último.
Índices estudiantiles de la población inmigrada y su diversificación en relación con factores socioeconómicos en el AMV
1981
1H NMR and IR spectra of methyl dichloropropanoates and butanoates
1981
Abstract Methyl dichloropropanoates and butanoates were synthesized and their 1H NMR and IR spectra were studied. Comparisons were made with the spectral characteristics of corresponding monochlorocompounds. Special attention was given to the elucidation of the characteristic spectral features associated with particular chlorine substitution patterns. The 1H NMR of erythro and threo methyl 2,3-dichlorobutanoates were analyzed using a computer program MAOCON, a modified LAOCOON 3 program. In the spectrum of the threo form the order of the chemical shifts of protons on asymmetric carbons seems to be opposite to that reported in earlier literature. Also vicinal coupling constants J23 were foun…
In vivo studies on the antiandrogenic effects of cimetidine versus cyproterone acetate in rats
1981
To investigate the antiandrogenic action of cimetidine in vivo, prostatic androgen uptake and metabolism, spermatogenesis, morphology of the prostate and testes, and plasma hormone levels were studied using Sprague-Dawley rats, and the results were compared with the effects of cyproterone acetate or castration. Cimetidine and cyproterone acetate caused significant reduction in the weights of the ventral prostate and testes. The changes of ventral prostate were accompanied by a dose-related epithelial atrophy. No adverse effect on spermatogenesis was observed after treatment with cimetidine at daily doses of 50 mg/kg or cyproterone acetate of 10 mg/kg. Although cimetidine treatment induced a…
Correlation between superoxide dismutase, glutathione peroxidase and catalase in isolated rat hepatocytes during fetal development
1981
Abstract Superoxide dismutase, glutathione peroxidase and catalase activities were determined in isolated fetal rat hepatocytes of various ages and compared with the values of neonatal and adult cells. The developmental pattern of superoxide dismutase and glutathione peroxidase were very similar with a low constant activity in the fetal cells and a postnatal burst. On the contrary catalase begins to increase already since the 18th day of the fetal life. The results suggest a functional correlation of superoxide dismutase and glutathione peroxidase in the antioxidative enzyme defense of liver cells.
Las delicias del poder
1981
Les procédures d'orientation dans le système scolaire et leurs implications dans la compréhension des relations entre la formation et l'emploi
1981
International audience; Le texte ci-après cherche à explorer en quoi les procédures d'orientation qui sont fondamentales dans la constitution de la segmentation de la population scolaire sont importantes pour la compréhension des phénomènes d'orientation. Il comprend trois parties. La première propose une réflexion d'ordre théorique sur l'orientation au niveau de la classe de 3ème et tente de poser des questions objectives, ayant un contenu empirique opératoire. La seconde partie donne des éléments empiriques sur l'orientation à la fin de La c lasse de 3ème. L'ensemble des questions posées dans la première partie aurait dû y trouver une réponse. Toutefois, des raisons techniques ont retardé…
Studies on the natural hemolytic system of the annelid worm Spirographis spallanzanii viviani (Polychaeta).
1981
Abstract Hemolytic activity in the hemolymph of Spirographis spallanzanii was estabilished against Bufo, sheep, calf, rabbit, rat, human A, B, O erythrocytes. Chemico-physical treatments suggest that the hemolytic factor could be a thermo-labile protein whose activity requires calcium ions and which is active over broad pH and temperature ranges. Some of these properties and the sigmoidal curve obtained by plotting the quantity of hemolymph against the percentage of hemolysis, produce some analogies with the mammalian lytic system.