showing 36 of ~574560 from 574555 documents
Laser spectroscopy of neutron deficient lead and thallium isotopes: Systematics of nuclear radii in the Z = 82 region
1989
Publisher Summary The high sensitivity achievable in laser spectroscopic methods allows the extraction of nuclear quantities even of artificially produced short-lived nuclides far off from nuclear stability. By analyzing the hyperfine structure and the isotope shift magnetic dipole moments, the electric quadrupole moments and the change of the nuclear charge radius can be studied. This chapter describes an experiment that was carried out at the GSI on-line mass separator using collinear fast atomic-beam laser spectroscopy. Radioactive lead and thallium isotopes were produced by bombarding natural tungsten targets with oxygen beams. For the lighter thallium isotopes, a tantalum target was us…
Apex caulinaires végétatifs à proméristème supère ou infère: quelques variantes principales chez les Plantes vasculaires
1989
ResumeDans le cadre general d'une nouvelle conception de l'organisation et de l'activite edificatrice dans le meristeme caulinaire, de nouveaux schemas sont proposes pour les Pteridophytes, Subspermaphytes et Gymnospermes, a partir de donnees bibliographiques. Toutes les variations constatees s'inscrivent de facon satisfaisante dans l'interpretation globale faisant intervenir une ou plusieurs plages de cellules initiales responsables des composantes longitudinale et diametrale de la croissance.
Myositiden bei Gefäß-Bindegewebskrankheiten
1989
Sammelbezeichnung fur Muskelveranderungen vom Typ der „interstitiellen Myositis“ bei Panarteriitis nodosa, Lupus erythematodes, Sklerodermie, rheumatoider Polyarthritis, Wegener-Granulomatose, Sjogren-Syndrom (Sicca-Komplex) u. a.
Phytoplankton Fluctuations during an Annual Cycle in the Coastal Lagoon of Cullera (Spain)
1989
The seasonal variation and the vertical distribution of the phytoplanktonic population of the lagoon of Cullera, an elongated coastal lagoon with estuarine circulation of water, has been studied in three sampling stations: mouth, centre and source. Seasonal variation is determined by a marine-freshwater interaction. In winter, the sea influence is important, a marine water wedge of anoxic water arrives at the sampling station located at the source and marine and brackish water species dominate the phytoplankton. Also marine species of zooplankton and fish enter the system, which may then be considered as exploited by the sea. In spring the marine wedge retreats from the source but remains i…
Estudio crítico de 11 casos de fracturas de 1/3 distal de fémur
1989
Presentamos 11 pacient.es con fractura en la extremidad dist.al del fémur, tratada quirúrgicamente con fijación interna rígida. Estudiamos los resultados en función de la movilización precoz y el tipo de inmovilización postoperatoria. Descriptores: Fractura Supracondilea de Fémur; Fractura de extremidad distal femoral; Fracturas de Fémur; Tratamiento. Eleven patients underwent rigid internal fixation of supracondylar,intercondylar and condylar fractures of the distal end of the femur are colected, 'loe authors study the results based in the posoperative motions.
Statistical Properties of Generalized Strain Criterion for Multiaxial Random Fatigue
1989
ABSTRACT Statistical properties of generalized criterion of the maximum shear and normal strains on the fracture plane have been presented, Functions of probability distribution and spectral density of the equivalent strain have been analysed on the assumption that a random tensor of strain state is a six-dimensional stationary and ergodic Gaussian process. The expected value and variance of the equivalent strain have been determined as well. From spectral analysis a new limitation has been derived for extension of some multiaxial cyclic fatigue criteria to random loadings. It is connected with the fact that in some cases the frequency band of the equivalent strain is greater than that for …
Exclusive Semileptonic B and D Decays
1989
Interest in semileptonic (s.l.) bottom meson decays in the last few years has focused on the lepton energy end point spectrum. Theoretical models were needed for the description of the endpoint spectrum in order to be able to experimentally extract values for the ratio of KM matrix elements |Vbu/Vbc|. As approximately 90% of the total s.l. decay rate of bottom mesons is into the exclusive modes D and D* it was quite natural to try and model the endpoint spectrum by exclusive contributions. This approach was pioneered by GILMAN, ISGUR and WISE (GIW) in [1].
Pourquoi des herbicides perdent-il leur efficacite ?
1989
National audience
Determinant Bundles over Grassmannians
1989
Denoting by H the Hilbert space of square-integrable Dirac spinor fields on a manifold M, transforming according to a unitary representation p of a gauge group G, we have a linear representation of the group g of gauge transformations in the space H. If ρ is faithful we can consider g as a subgroup of the general linear group GL(H). By constructing representations of GL(H) we automatically obtain representations of g. It turns out that in the case when the dimension d of M is odd, g is contained in a smaller group GLp ⊂ GL(H) which has the property that it perturbs the subspace H+ ⊂ H consisting of eigenvectors of a Dirac operator belonging to positive eigenvalues, by an operator A for whic…
La Segunda Edad del Hierro en la Baja Extremadura: problemática y perspectivas en torno al poblamiento
1989
Poblamiento de la Baja Extremadura en la Edad del Hierro
Encondroma cervical : (problemática diagnóstica a propósito de un caso)
1989
Se presenta un caso de encondroma vertebral localizado en región cervical, con sintomatología inicial de dolor cervical y más tarde con afectación radicular de miembros superiores. Confirmada mediante biopsia la naturaleza tumoral de la lesión, con el diagnóstico de encondroma, se aborda quirúrgicamente, extirpando los cuerpos vertebrales C5 y C6, exéresis que incluyó también el material discal en relación con dichas vértebras, realizando una artrodesis con injerto de creta iliaca. Después de dos años y medio el paciente se encuentra asintomático.
Randomisierte Tamoxifen-Loading dose-Studie: Bestimmung der Serumspiegel von Tamoxifen und 5 Hauptmetaboliten mit einer neuen HOPLC-Methode
1989
Je 20 Patientinnen mit Ostrogen- und/oder Progesteron-Rezeptor-positiven Mammakarzinomen oder Patientinnen mit unbekanntem Rezeptorstatus aber gunstigen Prognosekriterien wurden mit Tamofen® (Fa. Rhone-Poulence) einem der folgenden Therapieschemata unterworfen: 1.) 160 mg/Tag fur eine Woche, dann Umsetzen auf eine Dauerdosis von 20 mg/Tag; 2.) 80 mg/Tag fur eine Woche, Erhaltungsdosis 20 mg/Tag; 3.) 80 mg/Tag fur eine Woche, Erhaltungsdosis 40 mg/Tag; 4.) Dauerdosis 30 mg/Tag.
Intraoperative Evaluation of the Reconstruction of the Atrioventricular Valves by Means of Transesophageal Echocardiography
1989
In 44 operations, the mitral valve was reconstructed in 28 patients, the tricuspid valve in 12, and both atrioventricular (AV) valves in four. The results of reconstruction were tested first in the open arrested heart by injection of a crystalloid solution into the left or right ventricle, either through the reconstructed valve or via one of the great arteries. Upon termination of cardiopulmonary bypass the valve function was examined in the beating heart by transesophageal contrast echocardiography (TEE). For purposes of visualization, 0.5–1.0 cc of agitated Gelifundol was injected into the ventricle. In 31 patients, open testing and echocardiographic visualization showed identical, good o…
Adiós, paraíso, adiós
1989
Small Particles and Thin Films of Metals on Ceramic Oxides
1989
This paper is aimed at presenting some recent ideas and experimental results on characterization and properties of small particles and thin films of metals on oxide surfaces. Analysis is restricted to metallic films on well-defined surfaces, mainly monocrystalline surfaces and to ceramic oxides having a marked ionic character. The properties of metallic films obtained by chemical reduction of oxides and those of deposits are compared. Nucleation and growth modes are described. Interfacial properties are analysed in terms of size or thickness effect and in the general framework of the ceramic-metal bonding.
Pseudohalide derivatives of manganese(II) and copper(II) complexes with mepirizole, a biologically active pyrimidyl-pyrazole ligand
1989
Abstract The synthesis and characterization of thiocyanate and azide derivatives of mepirizole(4-methoxy-2-(5-methoxy-3-methyl-pyrazol-1-yl)-6-methylpyrimidine, hereinafter L) with manganese(II) and copper(II) is reported. The compounds were characterized by IR, electronic and EPR spectra and analytical data. Spectroscopic results suggest the existence of dimeric neutral entities [L2Cu2(μ-X)2(X)2] (X = NCS or N3) with unsymmetrical end-to-end bridges and five-coordination geometry around the copper(II) ion. Magnetic susceptibility data show that in the azide derivative the copper atoms are antiferromagnetically coupled (J = −18 cm−1), but no magnetic exchange interaction could be detected i…
Emplois et tourisme en Bourgogne
1989
National audience
Tratamiento Quirúrgico de la Hernia Discal Lumbar : estudio comparativo entre las técnicas convencional y microquirúrgica
1989
The authors report their own experience of microsurgery for treatment of lumbar disc herniation compared with conventional technique. For that the authors analyze, on a retrospective way, 200 cases distribute in two homogeneous groups. In the results, before an analysis of the epidemiological, clinical and diagnostic dates, the authors shows, through a statistical study, the complications rate, the global results and the mean time until return to work. This time was notably smaller and statistically significant for the patients operated with microsurgical technique.
Assessment of left ventricular function during aortic balloon valvuloplasty by transesophageal echocardiography
1989
Several reports have documented the feasability and utility of balloon aortic valvuloplasty as a palliative treatment for high-surgical-risk patients with critical aortic valve stenosis (1–3).
Mechanisms for the Decay of Unstable and Metastable Phases: Spinodal Decomposition, Nucleation and Late-Stage Coarsening
1989
The basic concepts on the kinetics of phase separation in alloys are introduced, and the current status of the theory is briefly reviewed. Particular emphasis is given to questions such as the conditions under which the linearized theory of spinodal decomposition is valid, the significance of spinodal curves, the possible description of coarsening in terms of power laws and structure-factor scaling, and non-equilibrium percolation phenomena.
The Thunen's rent rediscovered (some reflections on the history of spatial thought)
1989
Von Thünen’s thought about land rent has often been oversimplified by modern economists: the aim of this paper is to analyse the properties of the original rent function of The Isolated State. We give a mathematical reformulation of Thünen’s reasoning and we show its richness, its curiosities and olso its limits. None of the Thünen’s rent functions is linear, and the original model is anable to assure that they are decreasing with distance to the center.
Controlled release of drugs: Polymers and aggregate systems. Edited byM. Rosoff, VCH Verlagsgesellschaft, Weinheim, 1989, xi, 315 pp., bound, DM 132.…
1989
Myopathien bei endokrinen Störungen
1989
Meist leichte proximale →Myopathie mit generalisierter Muskelschwache, Muskelhypertrophie und vorzeitige Ermudbarkeit. Eine Kombination neurogener und myogener Veranderungen bei hypophysarem Gigantismus wurde beschrieben.
Suomalaisen koulutusjärjestelmän kielikoulutus ja sen relevanssi. Osa 1
1989
The present study is the first part of a research project concerned with language teaching in the Finnish educational system, and its relevance. This part examined language choices in the comprehensive school, in the upper secondary school and in vocational education, as well as problems related to language choices and measures needed to overcome them. Furthermore, the study was concerned with the number of books university students had to read for their examinations and the language the books were written in. Answers were sought by means of questionnaires sent to school administration authorities and by means of content analysis of degree requirements. It seems difficult to weaken the domi…
Possible involvement of gibberellins on leaf expansion and carbohydrate accumulation in Citrus
1989
During the spring flush of growth both vegetative shoots and inflorescences are formed in Citrus. Some of these inflorescences bear both flowers and leaves (GOLDSCHMIDT and MONSELISE 1972). The leaves from leafy inflorescences are smaller in size (GUARDIOLA et al. 1984) and differ in composition, both organic (SANZ et al. 1987b) and mineral (EMBLETON et al. 1973) as compared to leaves from vegetative sprouts. Some of these differences are related to the competition of nearby developing flowers and fruitlets, but a different type of regulation may also be involved. Early removal of developing reproductive organs had no effect on leaf growth (SANZ et al. 1987a). Further, inflorescence leaves …
Meson-retardation effects in deuteron photodisintegration below ?-threshold
1989
Mesor-retardation effects in photodisintegration of the deuteron below pion threshold are studied by constructing retarded one-boson-exchange potentials using time-dependent non-covariant perturbation theory. The corresponding retarded meson-exchange currents including retarded vertex currents are derived analogously by gauge-invariant minimal coupling. It is found that retardation effects in the wave functions and in the electromagnetic currents as well have a significant influence on total and differential cross sections.
L'impact économique du tourisme en Bourgogne
1989
National audience
Descubrimientos de una factoría bajoimperial de salazón de pescados en Santa Pola (Alicante)
1989
Multiple chromosome polymorphism in the gobiid fish Gobius niger jozo L. 1758 (Pisces, Gobiidae).
1989
By analysing chromosome preparation from 42 Gobius niger jozo specimens from the Gulf of Palermo (Sicily), four different karyotypes were observed: A (2n=52; NF=60), B (2n=51; NF=60), C (2n=50; NF=60) and D (2n=49; NF=60). A chromosome polymorphism due to Robertsonian fusion is present in this species.
The Clinical Enzymology of the Complement System
1989
The complement (C) system is one of the most important humoral systems mediating many activities that contribute to inflammation and host defense, e.g. various anaphylatoxin activities, Chemotaxis and opsonization for phagocytosis. The C system is similar to other humoral systems, such as coagulation, fibrinolysis and the kinin system, a multifactoral system whose activation represents sequentially occurring multi-step activation cascades of the “classical” as well as the “alternative” pathway.
Cmentarz Łyczakowski we Lwowie w latach 1786-1986
1989
Determination of fluoride after direct separation from acid medium by collection of its volatile compounds
1989
A method is proposed for determination of fluoride by separation in acid medium followed by ion-selective electrode measurement. The separation is done at temperatures up to 200 °C, without any previous treatment of the sample, in a PTFE reactor designed to ensure the complete absorption of volatile fluoride compounds. The distillation variables (temperature, time and acid concentration) have been optimized and the interference of other various species in the separation step has been studied. The method has been applied to geological samples. The results obtained are statistically satisfactory.
Durch sterische effekte stabilisierte ß-ketocarbonsäuren
1989
Abstract Increasing steric hindrance in β-keto carboxylic acids leads to an increasing kinetic stability towards decarboxylation, till systems are reached which are completely stable at room temperature. Simultaneously the tautomeric equilibrium is changed in favour of the (Z)-enol, and finally in favour of the (E)-configurated enol.
Aegopinella bourdieri nov. sp. (Gastropoda: Zonitidae),une espèce nouvelle du Pléistocène normand (France)
1989
St Pierre-les-Elbeuf (Normandy, NE France) is a reference site for the middle and the upper Pleistocene of NW France. In the eastern part of the quarry, the paleosoils Elbeuf III and IV are truncated, white sands and a small tufa lay on Elbeuf IV. Similar deposits have been recognized at Vernon (Seine valley) and at Arrest (northern France). They are probably contemporaneous (Holsteinian) and each of them has yielded an interglacial malacological fauna. The faunal communities are interesting because they are composed by species living up to now in this country, by emigrated species and by fossil species. Among them, A. bourdieri is a new fossil taxa, endemic of Holsteinian tufas of Normandy…
Das Problem des Todes in der deutschen Dichtung des Barock
1989
Das Thema der folgenden Gedankengange ist nicht willkurlich formuliert. Die darin angebotene zeitliche und inhaltliche Akzentuierung entspricht einer geistesgeschichtlich bedingten Grenzsituation menschlicher Erkenntnis. Zwischen etwa 1620 und 1720, im sogenannten Jahrhundert des deutschen Barock, wahlen drei Generationen dieses Thema fur ihre Dichtungen, ohne das ihr Fragen eine gultige Antwort erfahrt: So wird das Nachdenken uber den Tod zu einem Problem, dem der Einzelne sich in den verschiedenen Abschnitten seines Erdendaseins nahert und entsprechend verschiedene Losungen in poetischer Form niederlegt. Diese Verschiedenheit der Losungsmoglichkeiten der Todesproblematik, die bis zu krass…