578 research outputs found

    Multicenter-study of operative treatment of intraligamentous tears of the anterior cruciate ligament in children and adolescents: Comparison of four different techniques

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    Tears of the anterior cruciate ligament in skeletally immature patients were operated with four different methods and their outcome compared to each other. Sixty-eight patients (33 males, 35 females), mean 12.5years, were treated in four different centers from 1984 to 2001. Twenty-eight patients underwent the ACL-reconstruction with hamstring grafts, 16 patients with bone-patella-bone autografts, 12 patients with quadriceps grafts and 12 patients with facia lata. The mean follow-up was 32months. Postoperative evaluation included radiographs, KT-1000/2000 stability measurements, Lysholm score, The Tegner activity scale and IKDC score. Neither leg length discrepancy nor angular deformities were noted. Mean KT-1000 difference was 2.1mm, mean postoperative Lysholm knee score 93.3, IKDC 87% normal or nearly normal. The Tegner index decreased from 6.6 to 5.7. In total, six patients developed instability due to an adequate trauma 1year after the index operation. Two patients showed mild arthrotic changes. All but two patients were able to return to the same level of preoperative sports participation. None of the four methods studied showed major differences in outcome compared to the other. No growth disturbance could be note

    Nueva escuela elemental, en Eichstätt

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    A modem elementary school has been built over part of the old moat at Eichstätt. The diferences in level of the ground have been exploited in order to achieve a more interesting distribution of the school buildings. The main building is L shaped. It contains 11 classrooms, workshops and a large recreation hall, which are located within the ground floor of one of the wings. The other wing includes the management's staircase, special classrooms, the hall porter's quarters and heating installations. Near the main building there is another block housing four classrooms, and both buildings are separated by a recreation ground, and connected by a roofed path. A further block, nearby, contains the gymnasium. There is direct access from the street to this building. The foundations consist of concrete piles, supported laterally by means of reinforced concrete beams. The floor and staircase structure is also made of reinforced concrete, and the roof is covered with fibrocement sheeting. The clever distribution of the inner courtyards, which are to be decorated with small gardens, the emplacement of the building in the moat, and the powerful contrast between the old city wall and the new buildings give the project a charming quality within the urban background, which also helps to emphasize even more the interest of the historical monuments.Una moderna escuela elemental ha sido construida sobre parte del viejo foso de la ciudad de Eichstätt, aprovechando para disponer los diversos bloques, las posibilidades que ofrecen los desniveles del terreno. La construcción principal —con planta en forma de L — contiene 11 clases, talleres y una gran nave para el recreo, situada en el piso inferior en uno de los brazos. En el otro están: la escalera de dirección, clases especiales, conserjería y vivienda del conserje e instalación de calefacción. Junto al edificio principal hay un bloque de cuatro clases, separado por un patio de recreo y enlazado por medio de un paso cubierto. En otro bloque inmediato está el gimnasio con acceso directo desde la calle. La cimentación se ha realizado mediante pilotes de hormigón arriostrados con vigas de hormigón armado; los techos y escaleras son asimismo de hormigón armado y en la cubierta han sido utilizadas planchas de fibrocemento. Una adecuada colocación de los patios interiores con vista a la horticultura, su posición en el foso, y el contraste entre el antiguo muro de la ciudad y el nuevo, le imprimen un acento encantador desde el punto de vista urbanístico, y ayuda a resaltar aún más los monumentos históricos

    Analyse der Veränderungen von Wavelet-transformierten elektromyographischen Signalen, wie sie beim Tragen einer Kniebandage entstehen

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    Der Vergleich von diversen Elektromyogrammen stellt eine wesentliche Anforderung an die Datenanalyse dar. Das Ziel der vorliegenden Arbeit ist es, eine Methode mit geringem mathematischem Aufwand vorzustellen, mit der kleine Veränderungen am Bewegungsapparat durch Auswertung des EMG-Signals einfach und mit einer hohen Sensitivität ermittelt und dargestellt werden können. Die Wavelettransformierten Elektromyogramme bilden Intensitätsbilder, die in einem Bildraum als Punkte dargestellt werden können. Die Distanz-analyse der Bildpunkte im Bildraum erlaubt es festzustellen, ob zwei Gruppen von Elektromyogrammen - im vorliegenden Falle diejenigen, die beim Gehen mit und ohne Kniebandage gemessen wurden - sich im Mittel signifikant unterscheiden. Die Methode definiert eine Distanz-Winkel-Darstellung und Differenz-Intensitätsbilder, die es erlauben, die Auftrennung optisch zu beurteilen. Es ist zu erwarten, daβ bei gröβeren Interventionen die Unterschiede deutlicher erscheinen werden. The comparison of electromyograms represents a challenge for data analysis. The aim of the project was to present a method that uses a minimal computational effort to resolve small but significant changes in the muscular activity that occur while walking with and without a knee brace. The wavelet transformed electromyograms were represented as intensity patterns that resolve the power of the signal in time and frequency. The intensity pattern of each electromyogram defines single points in a pattern space. The distance between these points in pattern space were used to detect and show the separation between the groups of electromyograms that were recorded while walking with and without a knee brace. The method proposes a distance versus angle representation to visually discriminate the intensity patterns. Once it has been shown that the differences are statistically significant, one can visualize the result in a difference intensity pattern that indicates at what time and at what frequency the electromyograms vary between the two conditions tested. It is to be expected that interventions that are more intrusive than a knee brace will reveal even more distinct difference

    Local impact of solar variation on NO2 in the lower mesosphere and upper stratosphere from 2007 to 2012

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    MIPAS/ENVISAT data of nighttime NO2 volume mixing ratios (VMR) from 2007 until 2012 between 40 km and 62 km altitude are compared with the geomagnetic Ap index and solar Lyman-α radiation. The local impact of variations in geomagnetic activity and solar radiation on the VMR of NO 2 in the lower mesosphere and upper stratosphere in the Northern Hemisphere is investigated by means of superposed epoch analysis. Observations in the Northern Hemisphere show a clear 27-day period of the NO2 VMR. This is positively correlated with the geomagnetic Ap index at 60-70° N geomagnetic latitude but also partially correlated with the solar Lyman-α radiation. However, the dependency of NO2 VMR on geomagnetic activity can be distinguished from the impact of solar radiation. This indicates a direct response of NOx (NO + NO2) to geomagnetic activity, probably due to precipitating particles. The response is detected in the range between 46 km and 52 km altitude. The NO2 VMR epoch maxima due to geomagnetic activity is altitude-dependent and can reach up to 0.4 ppb, leading to mean production rates of 0.029 ppb (Ap d)-1. Observations in the Southern Hemisphere do not have the same significance due to a worse sampling of geomagnetic storm occurances. Variabilities due to solar variation occur at the same altitudes at 60-70° S geomagnetic latitude but cannot be analyzed as in the Northern Hemisphere. This is the first study showing the direct impact of electron precipitation on NOx at those altitudes in the spring/summer/autumn hemisphere. © 2014 Author(s).F. Friederich and M. Sinnhuber gratefully acknowledge funding by the Helmholtz Association of German Research Centres (HGF), grant VH-NG-624Peer Reviewe

    QM/QM approach to model energy disorder in amorphous organic semiconductors

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    Local impact of solar variation on NO2 in the lower mesosphere and upper stratosphere from 2007 to 2012

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    MIPAS/ENVISAT data of nighttime NO2 volume mixing ratios (VMR) from 2007 until 2012 between 40 km and 62 km altitude are compared with the geomagnetic Ap index and solar Lyman-α radiation. The local impact of variations in geomagnetic activity and solar radiation on the VMR of NO 2 in the lower mesosphere and upper stratosphere in the Northern Hemisphere is investigated by means of superposed epoch analysis. Observations in the Northern Hemisphere show a clear 27-day period of the NO2 VMR. This is positively correlated with the geomagnetic Ap index at 60-70° N geomagnetic latitude but also partially correlated with the solar Lyman-α radiation. However, the dependency of NO2 VMR on geomagnetic activity can be distinguished from the impact of solar radiation. This indicates a direct response of NOx (NO + NO2) to geomagnetic activity, probably due to precipitating particles. The response is detected in the range between 46 km and 52 km altitude. The NO2 VMR epoch maxima due to geomagnetic activity is altitude-dependent and can reach up to 0.4 ppb, leading to mean production rates of 0.029 ppb (Ap d)-1. Observations in the Southern Hemisphere do not have the same significance due to a worse sampling of geomagnetic storm occurances. Variabilities due to solar variation occur at the same altitudes at 60-70° S geomagnetic latitude but cannot be analyzed as in the Northern Hemisphere. This is the first study showing the direct impact of electron precipitation on NOx at those altitudes in the spring/summer/autumn hemisphere. © 2014 Author(s).F. Friederich and M. Sinnhuber gratefully acknowledge funding by the Helmholtz Association of German Research Centres (HGF), grant VH-NG-624Peer Reviewe

    Receiver function images of the Hellenic subduction zone and comparison to microseismicity

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    New combined P receiver functions and seismicity data obtained from the EGELADOS network employing 65 seismological stations within the Aegean constrained new information on the geometry of the Hellenic subduction zone. The dense network and large data set enabled us to estimate the Moho depth of the continental Aegean plate across the whole area. Presence of a negative contrast at the Moho boundary indicating the serpentinized mantle wedge above the subducting African plate was seen along the entire forearc. Furthermore, low seismicity was observed within the serpentinized mantle wedge. We found a relatively thick continental crust (30–43 km) with a maximum thickness of about 48 km beneath the Peloponnese Peninsula, whereas a thinner crust of about 27–30 km was observed beneath western Turkey. The crust of the overriding plate is thinning beneath the southern and central Aegean and reaches 23–27 km. Unusual low Vp / Vs ratios were estimated beneath the central Aegean, which most likely represent indications on the pronounced felsic character of the extended continental Aegean crust. Moreover, P receiver functions imaged the subducted African Moho as a strong converted phase down to a depth of about 100 km. However, the converted Moho phase appears to be weak for the deeper parts of the African plate suggesting nearly complete phase transitions of crustal material into denser phases. We show the subducting African crust along eight profiles covering the whole southern and central Aegean. Seismicity of the western Hellenic subduction zone was taken from the relocated EHB-ISC catalogue, whereas for the eastern Hellenic subduction zone, we used the catalogues of manually picked hypocentre locations of temporary networks within the Aegean. Accurate hypocentre locations reveal a significant change in the dip angle of the Wadati–Benioff zone (WBZ) from west (~ 25°) to the eastern part (~ 35°) of the Hellenic subduction zone. Furthermore, a zone of high deformation can be characterized by a vertical offset of about 40 km of the WBZ beneath the eastern Cretan Sea. This deformation zone may separate a shallower N-ward dipping slab in the west from a steeper NW-ward dipping slab in the east. In contrast to hypocentre locations, we found very weak evidence for the presence of the slab at larger depths in the P receiver functions, which may result from the strong appearance of the Moho multiples as well as eclogitization of the oceanic crust. The presence of the top of a strong low-velocity zone at about 60 km depth in the central Aegean may be related to the asthenosphere below the Aegean continental lithosphere and above the subducting slab. Thus, the Aegean mantle lithosphere seems to be 30–40 km thick, which means that its thickness increased again since the removal of the mantle lithosphere about 15 to 35 Ma ago

    Effects of energy correlations and superexchange on charge transport and exciton formation in amorphous molecular semiconductors:an ab initio study

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    In this study, we investigate on the basis of ab initio calculations how the morphology, molecular on-site energies, reorganization energies, and charge transfer integral distribution affect the hopping charge transport and the exciton formation process in disordered organic semiconductors. We focus on three materials applied frequently in organic light-emitting diodes: α-NPD, TCTA, and Spiro-DPVBi. Spatially correlated disorder and, more importantly, superexchange contributions to the transfer integrals, are found to give rise to a significant increase of the electric field dependence of the electron and hole mobility. Furthermore, a material-specific correlation is found between the HOMO and LUMO energy on each specific molecular site. For α-NPD and TCTA, we find a positive correlation between the HOMO and LUMO energies, dominated by a Coulombic contribution to the energies. In contrast, Spiro-DPVBi shows a negative correlation, dominated by a conformational contribution. The size and sign of this correlation have a strong influence on the exciton formation rate
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