Die intraoperative Sonographie des Wirbelkanals — Experimentelle Standardisierung und erste klinische Erfahrungen

1991

Die dorsale operative Stabilisierung von Wirbelfrakturen, vor allem des thoracolumbalen Uberganges, mit einem Fixateur interne ist ein etabliertes Verfahren der Traumatologie. Das Ziel ist hier neben der Aufrichtung der Kyphose und der Wiederherstellung der Wirbelkorperhohe die Dekompression des Myelons durch die Reposition von Knochenfragmenten, die von der frakturierten Wirbelkorperhinterkante in den Spinalkanal hineinragen. In vielen Fallen gelingt die indirekte Reposition der Hinterkante alleine durch Kyphosekorrektur und Distraktion. In anderen Fallen mus der Wirbelkanal durch Laminektomie freigelegt und die Hinterkante direkt reponiert werden. Die Moglichkeiten, den Erfolg des Reposit…

Slow crack propagation in polyethylene: determination and prediction

1991

Abstract A model is developed connecting the stress intensity factor KI with the propagation rate d h d t of slow cracks. The model is based on the concept of the chain relaxation capability. Experimental KIversus d h d t data are reported for polyethylenes of varying molecular mass M, density ϱ, initial notch length h0 and at different stress levels σ. Predictions of the theory concerning the effect of each of these parameters on crack propagation are confirmed by the experimental results. In particular, the equation for KI as a function of d h d t does not contain h0 nor σ. Experimental plots of KIversus d h d t for common M but different h0 values coincide into a single curve. Also plots…

IL TERATOMA CERVICALE

1991

The Authors present a case of Cervical Teratoma in newborn and analyze the optimal diagnostic and therapeutic approach.

Strategical behaviours in French ambulatory care (a theoretical and empirical study)

1991

Specifying agency relationships between the different actors in ambulatory care - the patient, the physician, the insurance and public authorities - allows to render an account of the complexity and the specificity of the health system. After a presentation of the normative approach of the agency theory, we will focus on two agency relationships : the Relationship between the insurance and insured people and the relationship between the patient and the physician. The driving part of supply appears through the analysis of the relationship between the physician and the others : he is the agent of both the patient and public authorities. The issue is then the hypothesis of supplier induced dem…

La religiosidad de las mujeres en el medioevo castellano

1991

A comparative study on Kθ evaluation from [η]-M data in single and mixed solvents through various excluded volume theories

1991

Abstract By allowing for the dependence of B on molecular weight, through its relationship with A2, modified Flory-Fox-Schaefgen, Kurata-Stockmayer-Roig, Berry and Inagaki-Suzuki-Kurata equations are obtained, relating [η] to A2 and to Kθ. Through these equations, Kθ can be determined from data sets for [η]-A2. Because of the scarcity of these data sets, A2 values have been calculated from experimental data for [η] and trial Kθ values through two parameter theories, namely, through the Flory-Krigbaum-Orofino theory for Ψ. Iterative processes were followed until coincidence was obtained between trial Kθ values and those evaluated from the modified excluded volume equations. The method has be…

Fourier transform infrared analysis of paint solvents

1991

Abstract The composition of solvent mixtures employed in the paint industry was determined by Fourier transform infrared spectrometry. A procedure based on the use of the ratio between the absorbance of characteristic bands of each component permits the ratio between two solvents in a binary mixture to be determined, independently of the thickness of the sample film. Typical mixtures of xylol with butan-1-ol and with butyl acetate (xylol=mixture of o-, m- and p-xylenes) were used as model systems to develop the proposed procedure and the accuracy was determined using synthetic formulations. Another possible application of the procedure is the characterization of azeotropic mixtures.

Tergal glands of male and femaleCryptocercus punctulatus scudder (Dictyoptera: Cryptocercidae): Composition, sexual dimorphism, and geographic variat…

1991

International audience; Males and females of Cryptocercus punctulatus possess tergal glands, but they differ in position, size, morphology, and secretion chemistry. Compound A (linalyl acetate) is the most abundant of the 21 compounds found only in the secretion of these glands. Compound B, 4,6,8-trimethyl-7,9-undecadien-5-ol, is specific to the tergal secretion of females.C. punctulatus lives only in the United States; its distribution is disjunct. Compound A is found in samples from the eastern population but is absent in samples from the western population. The amount of compound B per gland in samples from the western population is at least twice as high as in the samples from the easte…

Search for a new weakly interacting particle

1991

Abstract A search for events of the type e + e − →l + l − X 0 , where X 0 can be any weakly interacting particle which couples to the Z, has been performed with the ALEPH detector at LEP, by searching for acollinear lepton pairs. Such particles can be excluded up to a mass of 7.0 GeV/c 2 for a value of the ratio of branching fractions, Br( Z →X 0 l + l − )/Br(Z→ l + l − ), greater than 2.5 × 10 −3 if the X 0 has third component of isospin, I 3 greater than 1 2 and decays to a pair of virtual gauge bosons. When this analysis is combined with the previous results of the Higgs particle searches from ALEPH, this limit can be extended to an X 0 mass of 60 GeV/c 2 .

Biochemical taxonomic differentiation between Mullus barbatus and mullus surmuletus (Pisces, mullidae)

1991

Abstract 1. 1. The electrophoretic data from seven enzymatic systems, codifying for 20 loci, and the patterns of general proteins from some tissues of Mullus barbatus and Mullus surmuletus were examined. 2. 2. The value of the genetic distance index as per Nei is 0.068, this criterium showing a high similarity between the two species. 3. 3. Species-specific patterns were found for the SOD enzyme and general proteins of the muscle.

Информатика: ЭВМ в образовании

1991

Cборник содержит 16 статей, отражавших результаты исследований по общим и прикладным вопросам применения компьютера в образовании. Рассматривается научные, методические и практические аспекты разработки содержания образовани в условиях компьютеризации, программно-методического обеспечения для обучения информатике.

Análisis de la introducción del concepto de campo

1991

The concept of field is one of the most importan! in Physics. Unfortunately secondary school students find it obscure and difficult to grasp. We argue that this is mainly due to an incorrect didactic treatment in Physics textbooks, wich causes the field idea to be seen as an artificial method to calculate the force, with a misleading superposition of the two concepts.

Deviance, did you get it? An experiment in reading to learn

1991

Abstract This article reports an experiment in which an attempt was made to test reading a scientific text under as natural study conditions as possible. After reading a lengthy text from a Sociology textbook in English, five out of 25 Finnish college students understood a basic concept the way it had been defined by a sociologist; 4 weeks later, after going over the text the second time in Finnish, the number increased to 12. However, even after the second reading of the text in their first language, only half of the students had learnt the basic concept. This indicates that the problems in studying were not only linguistic problems; they seem also to have been study skill problems in gene…

Separate processing of “color” and “brightness” in goldfish

1991

Spectral sensitivity was measured under different adaptation levels using a behavioral training technique in which the fish had to discriminate between a dark test field and a test field illuminated with monochromatic light. Depending on which of the two test fields was used as training test field, two functions were obtained which differ (1) in absolute sensitivity and (2) in shape. When trained on the dark test field, the fish seems to discriminate on the basis of a "color" cue, but it uses a "brightness" cue when trained on the illuminated test field. This was concluded from measurements of wavelength discrimination. Under low levels of the adaptation light (1.5 and 0.2 lx instead of 20 …

The yttrium chloride-1,10-phenanthroline interaction: Synthesis and X-ray crystal structure of the complex [Y(OH)(H2O)2(phen)2]2Cl4·2(phen)·MeOH

1991

Abstract Investigations on the reaction between YCl3·H2O and phen (1,10-phenanthroline) led to the isolation of the title compound. The synthesis, IR and X-ray structural characterization are described. The crystal contains centrosymmetric binuclear dications [Y2(phen)4(μ-OH)2(H2O)4]4+, uncoordinated chloride anions, two clathrated phen molecules and a disordered methanol molecule. The yttrium ions are eight-coordinated with square antiprismatic geometry to the nitrogen atoms of two phen molecules, to bridging hydroxyl groups and to two water molecules. The Y ⋯ YI separation in the dimer is 3.651(2)A˚.

Synthesis, properties and crystal structure of bis(metiamide)bis(isothiocyanato)nickel(II)

1991

Abstract The crystal structure of Ni(metiamide)2(NCS)2 was determined by X-ray diffraction methods. Unlike cimetidine, which is a tridentate ligand, metiamide (C9H16N4S2): N-Methyl-N-[2-{(5-methylimidazol-4-yl)methylthio}ethyl]thiourea (which also possesses three potential donor sites) is bidentate, coordinated to the nickel atom through N(imidazole) and S(thioether) atoms. The S(thiourea) atom does not take part in the coordination; instead, the isothiocyanate ion is coordinated through nitrogen to the metal atom. The nickel atom lies on a centre of symmetry in an elongated octahedral environment: the nitrogen atoms occupy equatorial positions (NiN = 2.04 and 2.06 A) and S(thioether) atom…

Deuteron photodisintegration at low energies

1991

All presently available experimental data on deuteron photodisintegration below 40 MeV (i.e., total and differential cross sections, photon asymmetry and neutron polarization) are collected and carefully compared with the present status of the conventional theory (i.e., in the framework of mesontheoretical or semi-phenomenologicalN-N potentials including subnuclear degrees of freedom and relativistic corrections). No significant evidence for a failure of the conventional theory is found within the present experimental accuracy.

The inclination effect on the performance of water-filled heat pipes

1991

Abstract Heat pipes have been used in wide ranges of applications today including solar engineering. During this research study, the inclination dependent performance of water filled heat pipes was investigated both theoretically and experimentally for solar energy applications. The results showed that the performance of water-filled heat pipes are strongly dependent on the inclination and the heat source temperatures. As a general result, the heat transfer capability of water filled heat pipes is reduced dramatically below a 45° tilt angle.

Checks and balances and international openness

1991

In the course of a long digression within his famous inspection of Plato’s political philosophy, Karl Popper (1945: 121) argues that “the problem of politics” is the following: “How can we so organize political institutions that bad or incompetent rulers can be prevented from doing too much damage?” Popper’s answer is: “the theory of checks and balances”, which he defines as the striving to establish “institutional control of the rulers by balancing their powers against other powers” (122). From that general approach to “the problem of politics”, it follows that democracy is definitely not the rule of the majority, or the sovereignty of the people (a conception that entails various paradoxe…

MECCANIZZAZIONE DELLA COLTURA DEL CARCIOFO IN SICILIA

1991

La répression politique en Eure-et-Loir au début de la Restauration (1815-1817)

1991

Malum arbor. El código semiológico de la manzana

1991

A TRAVES DEL ESTUDIO SIMBOLICO DEL MANZANO SE ABORDA LA MAS IMPORTANTE CARACTERISTICA DEL CODIGO SEMIOLOGICO DE ESTA FRUTA Y DEL ARBOL QUE LO OFRECE. MEDIANTE LA ASOCIACION DE LA MANZANA CON EL PECADO ORIGINAL, EL MANZANO HA SIDO IDENTIFICADO COMO UN ARBOL DE SALVACION Y LA MANZANA COMO FRUTO DEL AMOR. IDEAS CODIFICADAS COMO RESULTADO DE LA CULTURA OCCIDENTAL. EL PRESENTE ESTUDIO PLANTEA LAS CUESTIONES DEL CODIGO EN UN SENTIDO DIACRONICO, TENIENDO EN CUENTA LAS TRADICIONES LITERARIAS Y GRFICAS, Y CULMINANDO CON EJEMPLOS QUE TRASMITE LA EMBLEMATICA DE LOS SIGLOS XVI Y XVII. (A.B.C./ L.A.G.)

Diabetic retinopathy: Monitoring of the macro and microrheological parameters after oral administration of a single dose of calcium dobesilate (Doxiu…

1991

Non Linear Phenomena in Oxidation of Metals and Alloys

1991

Analyse de quelques exemples du comportement non conventionnel des couches de corrosion obtenues par oxydation ou sulfuration de certains metaux et alliages

Metalloporphyrins with metalmetal σ-bonds. Synthesis, spectroscopic characterization, and electrochemistry of (P)MRe(CO)5 where P is the dianion of …

1991

Abstract The synthesis, physicochemical properties, and electrochemistry of a new series of metal metal σ-bonded metalloporphyrins are reported. The investigated compounds are represented as (P)MRe(CO)5 where P is the dianion of octaethylporphyrin (OEP) or tetraphenylporphyrin (TPP) and M = Al, Ga, In, or Tl. These compounds provide the first examples of Al and Ga metalloporphyrins with covalent metalmetal bonds as well as give the first series of compounds in which the same metalate anion is covalently bonded to four different group 13 metalloporphyrins. Each synthesized complex was characterized by 1H NMR, IR, and UV-visible spectroscopy as well as by electrochemistry. Graham Δσ and Δπ …

Transition from self tilt to object tilt during maintained lateral tilt in parabolic flight.

1991

Abstract 19 young healthy subjects were subjected to parabolic rollercoaster flight. A horizontal luminous line was seen by the subjects in a headfixed goggle device. During the hypergravic phases of parabolic flight the luminous line seemed to rotate into and during the hypogravic phase against the direction of static head tilt. Ocular counter rotation and activity of the neck position receptors cannot explain these subjective rotations. We conclude that information from the otolith system, converging with visual information within the brain, dislocated the headfixed visual target line. While the retinal image of the luminous line remains unchanged, loading and unloading the otoliths in pa…

El terror de ver

1991

Reflexión en torno a la representación de la muerte en combate a partir de las noticias referentes a la guerra del Golfo.

Parmentier

1991

Estudio exploratorio de los efectos sobre el rendimiento en el ataque de jugadores de balonmano, categoría cadetes, de un programa de intervención ps…

1991

Un documento clave para la historia de la pintura cerámica valenciana del siglo XVIII. La apoteosis del sacramento para la pequeña fiesta del arzobis…

1991

ESTUDIO MONOGRAFICO DEL PANEL CERAMICO DEL SACRAMENTO, EN EL REAL COLEGIO DEL CORPUS CHRISTI DE VALENCIA, REALIZADO PARA LA CELEBRACION DE LA BEATIFICACION DEL VIRREY JUAN DE RIBERA EN 1796. PRESENTA UN DOCUMENTO INEDITO QUE CONTIENE VALIOSA INFORMACION SOBRE EL FABRICANTE, LA FECHA DE ENTREGA, ETC. FINALMENTE, EL ARTICULO DESCUBRE LOS MODELOS UTILIZADOS POR EL PINTOR CERAMICO Y LAS FUENTES QUE INSPIRARON A LOS GRABADORES. (A.B.C./ L.A.G.)

Factores pronósticos en el tratamiento del condrosarcoma

1991

Los autores 30 condrosarcomas tratados en su Departamento. Estudiando la distribución por sexos, edad, localización, supervivencia y los factores pronósticos respecto a la relación entre el tipo histológico, localización, tratamiento, origen y tiempo de evolución. Concluyen que son factores de mal pronóstico el grado histológico III, localización central, especialmente en ilíaco, origen primario de la enfermedad y un tiempo mayor de 6 meses entre el diagnóstico y el tratamiento The authors are reviewed 30 chondrosarcomas seen at their department of orthopaedics surgery. They studied the age distribution, sex, localization, survival and the prognostic factors between histopathology, localiza…

Conquista i repoblació de Dénia

1991

Lopez Elum, Pedro - Pedro.Lopez-Elum@uv.es

Factors Correlating with Restenosis after PTCA

1991

Since its introduction in 1977 [7, 8], PTCA has been widely used in patients with coronary artery disease. Restenosis with recurrence of angina remains the major problem, limiting the long-term success after PTCA. Reported restenosis rates vary from 17% to 47% [9–19, 22–26]. In larger series [12, 15, 26] a restenosis rate of about 30% was constantly found, irrespective of the definition of restenosis in use.

Giant axonal neuropathy and leukodystrophy

1991

Abstract An 11-year-old Persian boy, born to consanguineous parents, manifested a progressive gait abnormality beginning at 5 years of age. A severe cerebellar disorder developed with associated dysfunction of the peripheral nervous system, but no sign of mental impairment. The sensory and motor nerve conduction velocities were greatly reduced, especially in the lower extremities. Cerebrospinal fluid protein was normal. Computed tomography and magnetic resonance imaging revealed leukoencephalopathy, especially in the cerebellum, but also in periventricular areas. The diagnosis of giant axonal neuropathy was established by biopsy of the sural nerve. The few previous histologic examinations h…

Factores pronósticos del resultado de la quimionucleosis

1991

Los resultados exitosos de la quimionucleosis dependen íntimamente de una estricta selección de los pacientes. En el presente trabajo se revisa la influencia de diferentes factores preoperatorios, clínicos y radiológicos, sobre el resultado de la quimionucleosis a los dos años de evolución, a través de un estudio estadístico de los casos. Los autores destacan como factores de mal pronóstico, en su casuística, las lumbalgias aisladas o prolongadas y el régimen laboral autónomo. Ni el tamaño ni la localizatción, central o lateral, de la imagen herniaria influyeron de manera estadística significativa en el resultado de la discolisis. Tampoco el número de discos explorados o inyectados, ni la p…

La Gaule chevelue : similitudes et différences dans la vaisselle métallique des tombes et habitats de l'Europe tempérée

1991

International audience