1,990 research outputs found

    Follow-up of a new titanium-coated polyetheretherketone cage for the cervical spine

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    Poly-ether-ether-ketone (PEEK) cages have lower modulus of elasticity when compared with Titanium (TTN) cages. This suggests that PEEK-cages could show a lower rate of subsidence after anterior cervical discectomy-fusion (ACDF) and might lead to a lower loss of correction. We investigated the one to five year-results of standalone PEEK-TTN-porous coated cages in a patient cohort from 2014 to 2017. The patients underwent single-level ACDF for disc herniation and degenerative discopathy. Clinical and radiological outcome were assessed in 50 eligible patients after a mean of 27 months. Results: Solid arthrodesis was found in 84%. Neck disability index (NDI), and visual analogue scale (VAS) of neck and arm show comparable results to the literature. Conclusions: Clinical and radiological outcomes of ACDF with PEEK-body-cages with a porous coated surface show good bony integration. The modulus of elasticity, design, shape, size, cage surface architecture, as well as bone density, endplate preparation, radical microdiscectomy and distraction during surgery should be considered as important factors influencing the clinical results. One main advantage, over titanium cages, is the absence of MRI artifacts, allowing an excellent postoperative follow-up. inferior clinical outcome compared with bone grafts due to a higher elasticity modulus, which could result in cage subsidence.8 Nevertheless, due to structural properties, TTN implants are likely to provide a good osseo-integration9 and several clinical studies demonstrate successful results after implantation of TTN-cages.10-13 PEEKcages have a modulus of elasticity closely resembling that of cortical bone, which might lead to advantages in load sharing and stress distribution. This might reduce the subsidence rate with an improved segmental correction in the long term and a potentially higher fusion rate.14-16 A direct comparison of cervical TTNand PEEKcages in a clinical setting is very rarely found in the literature, 16, 17 and even less studies consequently compare the radiological results.16, 17 The latter studies showed the PEEK-implants being superior in maintaining cervical interspace height and achieving radiographic fusion, 16, 17 even suggesting to cease the application of TTN-cages in cervical spine surgery.16 A solution in-between are newer cages that combine the benefit of both materials: PEEK-body cages plasma-sprayed with a porous titanium surface which is tightly bonded to the PEEK surface.18, 19 On TTN alloy substrates, osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production than on poly-ether-ether-ketone.20 A group of Japanese surgeons found that TTN-coated PEEK cages exhibit radiographic signs of bone on-growth, as represented by vertebral cancellous condensation around the cage, compared with that around the uncoated PEEK cage.21 Therefore, a TTN-coated PEEK cage may have the potential to promote solid fusion and to improve clinical outcomes in cervical interbody fusion surgery. This keeps the ideal elasticity modulus close to a bonelike elasticity modulus and offers a highly biocompatible surface that is well tolerated by bone and allows its ongrowth to the porous surface. The aim of the present study is to assess clinical and radiological results of CeSpace XP®, a titanium-coated PEEK cage

    Anomalous phase of MnP at very low field

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    Manganese phosphide MnP has been investigated for decades because of its rich magnetic phase diagram. It is well known that the MnP exhibits the ferromagnetic phase transition at \Tc=292 K and the helical magnetic phase below \TN=47 K at zero field. Recently, a novel magnetic phase transition was observed at T=282T^* = 282 K when the magnetic field is lower than 5 Oe. However, the nature of the new phase has not been illuminated yet. In order to reveal it, we performed the AC and the DC magnetization measurements for a single crystal MnP at very low field. A divergent behavior of the real and the imaginary part of the AC susceptibility and a sharp increase of the DC magnetization was observed at TT^*, indicating the magnetic phase transition at TT^*. Furthermore a peculiar temperature hysteresis was observed: namely, the magnetization depends on whether cooling sample to the temperature lower than \TN or not before the measurements. This hysteresis phenomenon suggests the complicated nature of the new phase and a strong relation between the magnetic state of the new phase and the helical structure.Comment: 4 pages, 2 figure

    Modelos no lineales de previsión para series temporales de interés farmacéutico. Aplicación al caso de la escarlatina

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    En este trabajo se presentan los resultados obtenidos tras el ajuste de un modelo no lineal y un modelo robusto de predicción a la serie temporal correspondiente a la incidencia de la escarlatina en Catalunya desde el año 2000 hasta mediados del 2005, según los datos publicados en el Butlletí Epidemiològic de Catalunya (BEC) por el Departament de Salut de la Generalitat de Catalunya.El ajuste se ha realizado tanto por mínimos cuadrados como mediante el método de la mínima mediana de residuales. Los intervalos de confianza, dada la no normalidad de las residuales, se han estimado mediante la técnica del bootstrap. El modelo se ha validado comparando las predicciones realizadas para las últimas 47 semanas frente a los casos declarados en el BEC. Salvo episodios de incidencia aguda, las previsiones resultan aceptables.El modelo sinusoidal ajustado muestra una tendenciacon un periodo de 52 semanas, una incidencia máximahacia la segunda quincena de marzo y una mínima incidenciasobre la segunda quincena de septiembre. Lospuntos de inflexión se sitúan, aproximadamente, coincidiendocon los solsticios de verano e invierno

    EISCAT Svalbard radar-derived atmospheric tidal features in the lower thermosphere as compared with the numerical modeling ATM2

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    The EISCAT Svalbard radar (ESR) has obtained neutral wind field data down to 90 km altitude in two period runs in August 1998. This has been rendered possible by successful elimination of ground clutter echoes by the ESR staff. Features of the obtained tidal components are then comparatively studied with the ATM2 (Atmospheric Tidal Modeling Version 2) steady tidal model which assumes climatological background zonal flow. It is found that the results are fairly consistent with theoretical predictions that the diurnal component is almost evanescent with some indication of propagating characteristics, and that the semi-diurnal one is dominated by short vertical wavelength higher order mode prevalent at higher latitudes. The ter-diurnal component is also not in contradiction with non-linear interaction theory. Convincing delineation of these behaviors, however, awaits further study on the zonal wave number characteristics of relevant waves by longitudinal network collaborations

    Puesta a punto de la metodología de ejercicios de intercomparación para análisis de fertilidad de suelos. Primeros resultados

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    Este trabajo recoge la metodología de realización de un ejercicio de intercomparación entre laboratorios españoles que ofertan análisis de la fertilidad de los suelos. Se prepararon alícuotas de cada una de las dos muestras de gran volumen, tomadas en dos suelos con marcadas diferencias entre sí. Una vez testada la homogeneidad de alícuotas se envió una de cada suelo a cada uno de los veintiún laboratorios participantes, junto con instrucciones y un formato para remisión de resultados. En todo el proceso se veló especialmente por la confidencialidad de los resultados de cada participante. Recibidas las respuestas se procedió al análisis de resultados, asignación de valores de consenso y evaluación de cada resultado mediante el indicador “z-score”. El ejercicio ha sido muy bien recibido en un colectivo de laboratorios que no mantenía apenas contacto, y se ha mostrado muy eficaz en la caracterización de la calidad de los resultados emitidos. Se ha puesto en evidencia que hay parámetros con resultados muy homogéneos (pH) frente a otros con diferencias incompatibles con el uso agronómico fiable de los análisis (granulometría, fósforo asimilable, etc.). Queda de manifiesto la urgente necesidad de mantener periódicamente este tipo de ejercicio, como un control de calidad externo que aumente la fiabilidad de los laboratorios. This work includes the methodology for carrying out a proficiency testing program between Spanish laboratories that offer soil fertility analysis. Aliquots of each of the two large volume samples were prepared, taken from two surface horizons of soils with marked differences between them. Once the homogeneity of aliquots was tested, one sample of each soil was sent to each of the twenty-one participating laboratories, together with the instructions and a format for the submission of results. Throughout the process, special care was taken to ensure the confidentiality of the results of each individual participant. Once the responses were received, the results were analyzed, consensus values were assigned and each result was evaluated using the "z-score" indicator. The exercise was very well received by the participating laboratories, and has been very effective in characterizing the quality of the results issued. It has been shown that there are parameters with very homogeneous results (pH) compared to others with differences incompatible with the reliable agronomic use of analyses (granulometry, assimilable phosphorus, etc.). The urgent need to maintain this type of intercomparison exercise periodically, as an external quality control that increases the reliability of laboratories, is evident

    Influencia de diversos patrones ciruelo sobre las características agronómicas y la calidad del fruto de las variedades de ciruela ‘R.C. Bavay’ y ‘R.C. Tardía de Chambourcy’

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    4 Pags.- 1 Tabl.- 1 Fig. Contribución de los autores originalmente presentada, como comunicación, en el XIV Congreso Nacional de Ciencias Hortícolas (SECH 2015): Retos de la Nueva Agricultura Mediterránea (Orihuela, 3-5 junio 2015).En este trabajo se estudia la influencia de cinco patrones ciruelo (Adara, Ademir, Mirobolán 713 AD, Miral 3278 AD y Mirobolán B), sobre el comportamiento agronómico y la calidad del fruto de dos variedades de ciruela Reina Claudia (‘R.C. de Bavay’ y ‘R.C. Tardía de Chambourcy’). El ensayo se plantó en el invierno de 1994-95 en la finca de la Estación Experimental de Aula Dei-CSIC (Zaragoza), en un suelo pesado y calizo, característico del área mediterránea. Se ha evaluado la influencia del patrón sobre el vigor y supervivencia de los árboles, síntomas de clorosis, producción anual, acumulada y productividad de las distintas combinaciones. Entre los parámetros de calidad del fruto se determinaron: tamaño y firmeza, sólidos solubles (ºBrix), acidez valorable e índice de madurez. A los 18 años de la plantación, se han observado diferencias significativas entre patrones, tanto en los parámetros agronómicos como de calidad del fruto de la variedad injertada.Este trabajo ha sido financiado por el Ministerio de Ciencia e Innovación (MICINN) AGL-2005-05533 y AGL-2008-00283, cofinanciados por FEDER, así como por el Gobierno de Aragón (A44). C. Font es beneficiaria de una beca JAE-Pre del CSIC.Peer reviewe

    Atomic Carbon and CO Isotope Emission in the Vicinity of DR15

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    We present observations of the 3P1-3P0 fine structure transition of atomic carbon [CI], the J=3-2 transition of CO, as well as of the J=1-0 transitions of 13CO and C18O toward DR15, an HII region associated with two mid-infrared dark clouds (IRDCs). The 13CO and C18O J=1-0 emissions closely follow the dark patches seen in optical wavelength, showing two self-gravitating molecular cores with masses of 2000 Msun and 900 Msun, respectively, at the positions of the catalogued IRDCs. Our data show a rough spatial correlation between [CI] and 13CO J=1-0. Bright [CI] emission occurs in relatively cold gas behind the molecular cores, neither in highly excited gas traced by CO J=3-2 emission nor in HII region/molecular cloud interface. These results are inconsistent with those predicted by standard photodissociation region (PDR) models, suggesting an origin for interstellar atomic carbon unrelated to photodissociation processes.Comment: 11 pages Latex, 6 figures, Accepted for publication in The Astrophysical Journa

    Estado nutricional del árbol en las variedades de ciruelo ‘R.C. Bavay’ y ‘R.C. GF 1119’ injertadas sobre los patrones Ishtara y P. 8-13

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    4 Pags.- 2 Figs. Contribución de los autores originalmente presentada, como comunicación,en el XIII Congreso Nacional de Ciencias Hortícolas (SECH 2012): “Convergencia de las Tecnologías Hortofrutícolas” (Almería, abril 2012)En este trabajo se estudia la influencia de dos patrones ciruelo (Ishtara y P. 8-13), sobre el estado nutricional del árbol en las variedades de ciruelo ‘R.C. de Bavay’ y ‘R.C. GF 1119’. El ensayo se plantó en el invierno de 1993-94 en la finca de la Estación Experimental de Aula Dei – CSIC (Zaragoza), en un suelo pesado y calizo, característico del área mediterránea. Además se ha evaluado la influencia del patrón sobre el vigor y supervivencia de los árboles, síntomas de clorosis, producción anual, acumulada y productividad de las distintas combinaciones estudiadas. A los 18 años de la plantación, se han observado diferencias significativas entre patrones, tanto en el estado nutricional del árbol como en alguno de los parámetros agronómicos de la variedad injertada.Este trabajo ha sido financiado por proyectos CICYT (AGL 2005-05533 y AGL 2008-00283) y Gobierno de Aragón (Grupo A44). S. Jiménez es beneficiario de un contrato JAE-Doc del CSIC.Peer reviewe

    Large-scale mapping observations of the CI(3P1-3P0) and CO(J=3-2) lines toward the Orion A molecular cloud

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    Large scale mapping observations of the 3P1-3P0 fine structure transition of atomic carbon (CI, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mt. Fuji submillimeter-wave telescope. The observations cover 9 square degrees, and include the Orion nebula M42 and the L1641 dark cloud complex. The CI emission extends over almost the entire region of the Orion A cloud and is surprisingly similar to that of 13CO(J=1-0).The CO(J=3-2) emission shows a more featureless and extended distribution than CI.The CI/CO(J=3-2) integrated intensity ratio shows a spatial gradient running from the north (0.10) to the south (1.2) of the Orion A cloud, which we interpret as a consequence of the temperature gradient. On the other hand, the CI/13CO(J=1-0) intensity ratio shows no systematic gradient. We have found a good correlation between the CI and 13CO(J=1-0) intensities over the Orion A cloud. This result is discussed on the basis of photodissociation region models.Comment: Text file is 13 pages long, and 3 figure files (pdf format). NRO Report No. 508 (1999). University of Tokyo, Resceu 41/9

    Search for gravitational waves associated with the August 2006 timing glitch of the Vela pulsar

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    The physical mechanisms responsible for pulsar timing glitches are thought to excite quasinormal mode oscillations in their parent neutron star that couple to gravitational-wave emission. In August 2006, a timing glitch was observed in the radio emission of PSR B0833-45, the Vela pulsar. At the time of the glitch, the two colocated Hanford gravitational-wave detectors of the Laser Interferometer Gravitational wave observatory (LIGO) were operational and taking data as part of the fifth LIGO science run (S5). We present the first direct search for the gravitational-wave emission associated with oscillations of the fundamental quadrupole mode excited by a pulsar timing glitch. No gravitational-wave detection candidate was found. We place Bayesian 90% confidence upper limits of 6.3 x 10^(-21) to 1.4 x 10^(-20) on the peak intrinsic strain amplitude of gravitational-wave ring-down signals, depending on which spherical harmonic mode is excited. The corresponding range of energy upper limits is 5.0 x 10^(-44) to 1.3 x 10^(-45) erg
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