118 research outputs found
Infrared thermograms applied to near-field testing
Electromagnetic fields close to radiant structures can be measured quickly using an infrared camera. Examples of induced fields by wire antennas over a detection screen at distances shorter than one wavelength are presented. The measured thermograms agree with simulations that take into account heat propagation on the detection screenPeer ReviewedPostprint (published version
Active zone self-similarity of fractal sierpinski antenna verified using infra-red thermograms
The surface current distribution of a Sierpinski fractal antenna shows a self-similar behaviour determined by the self-similar properties of its geometry. The application of infra-red thermography to electromagnetic near field detection allows the experimental verification of the active region scaling of a fractal antenna operating at different bands.Peer ReviewedPostprint (published version
Cronoestratigrafía (Palinología) del Triásico Sudpirenaico y del Pirineo Vasco-Cantábrico
This paper presients a general chronostratigraphy of the south Pyrenean Triassic basi:d on palynological studies. The Triassic in Les Nogueres-Cadí and the Basque Country areas is divided into the Buntsandstein, Muschelkalk and Keuper facies and the Isábena Forrnation. The Conglomeratic, sandstone and lutitic Unit of the Buntsandstein in the Puerto dr Otxondo (Basque Country) presents Stellapollenites thiergartii and together with the absence of Praecirculina granifer, suggests a Lower-middle Anisian age. The Lutitic Unit of the Buntsandstein in Igüem, Sant Sebastia de Buseu and Baga (Les Nogueres-Cadí) presenits Illinites kosankeii and Stellapollenites thiergartii, and the absence of Praecirculina granifer, indicates a Lower Anisian age. The Muschelkailk in Hostalets (Les Nogueres) presents Camerosporites secatus, suggesting an upper Ladinian age. The transit zone between the Muschelkaik and the Keuper facies in Odkn (Cadí) shows a palynological assemblage with Patinasporites densus, Partitisporites quadruplicis and Staurosaccites quadrifidus, indicating a Camain age, possibly Middie-upper Camian. The lower part of the Keuper in Noguera de Tor and Adons, in the Les Nogueres area, presents a palynological assemblage with Classopollis, Granuloperculatipollis rudis, Ovalipollis ovalis, Praecirculina granifer and Triadispora. The abundance of Classopollis and the presence of Granul~p~erculatipollrius dis suggest a Norian age, possibly lower-middle. The upper part of the Keuper in La Nou (Pedraforca) is Rhaetian in age due to the presence of cf. Deltaidospora and cf. Taeniasporites. The base of tlie Isábena Formation in Noves de Segre presents Corollina zwolinskae and Cerebropollenites pseudomassulae, indicating a Rhaetian age. The palynological studies, together with the forarninifera and conodonta data, deteimine the existence of important stratigraphicc hiatuses in the south Pyrenean Triassic supercycle
A detailed stream sediment Geochemical survey in the Canoves St. Pere de Vilamajor area (Montseny massif. NE Spain)
Se ha realizado una prospección geoquímica táctica de sedimentos aluviales en el Brea de Cánoves-St. Pere de Vilamajor (Macizo del Montseny, Barcelona), como consecuencia de una exploración geoquimica estratégica de sedimentos aluviales previa, en la que se localizó un Brea anómala en Pb, Zn, Cu, As, Cd, Ni, y Co. El Brea estudiada tiene 35 km2 y esta constituida por materiales sedimentarios y volcánicos del Paleozoica, metamorfizados en mayor o menor grado e intruidos por el granito de Vallfornés, y materiales detríticos terciarios. Las muestras, recogidas con una densidad de 7 por Km2 fueron, an alizadas mediante espectrofotometria de absorción atómica para el Pb, Zn, Cu, Ni, Co, As, Cd y Ag, con analisis adicionales para el Sn y W con fluorescencia de rayos X. La interpretación estadistica de los resultados mediante técnicas univariables y multivariables permitió localizar y delimitar los sectores mas anórnalos. Posteriores reconocimientos geológicos de detalle permitieron descubrir un nuevo tipo de mineralización estratiforme relacionado con los niveles volcano-sedimentarios del Ordovícico superior hasta el momento desconocido en las Cadenas Costero Catalanas, asi como sus removilizaciones debido al emplazamiento del granito de Vallfornés, que originaron mineralizaciones de tipo skarn y filonianas
Aportación de la densitometría ósea en las artroplastias de rodilla
El presente trabajo consiste en una revisión clínica y radiológica de 84 artroplastias
modulares de rodilla de las cuales, en 19 se ha estudiado la masa ósea periprotésica
(7 cementadas y 12 sin cementar) antes, al mes y a los seis meses de la intervención mediante
un densitómetro de doble fotón. Aparte, se ha probado la correlación directa entre la indicación
peroperatoria de no cementar y una mayor masa ósea en todas las zonas periprotésicas;
por otro lado, se ha observado una diferente distribución de la densidad mineral ósea en la
tibia tras la intervención, según se haya utilizado o no cemento. Estos hallazgos confirman el
estudio densitométrico previo a la intervención como un método complementario útil en la
indicación de la cementación de la artroplastia total de rodilla.A clinical and radiological revision of 84 modular knee arthroplasties is
presented. Periprosthesis bone mineral content was studied in 19 prostheses (7 cemented
and 12 uncemented) before, surgery one and 6 months after the intervention using a densitometer
of double energy. A direct correlation between the implantation of a non-cemented
prosthesis and the growth of the bone mass in all the periprosthesis areas was found, existing
a different distribution of the mineral bone density of the tibia after the intervention
depending on the use of cement. These findings show that the densitometric study previous
to an intervention as a useful complementary method in the indication of cemented total
knee arthroplasty
Red Queen Coevolution on Fitness Landscapes
Species do not merely evolve, they also coevolve with other organisms.
Coevolution is a major force driving interacting species to continuously evolve
ex- ploring their fitness landscapes. Coevolution involves the coupling of
species fit- ness landscapes, linking species genetic changes with their
inter-specific ecological interactions. Here we first introduce the Red Queen
hypothesis of evolution com- menting on some theoretical aspects and empirical
evidences. As an introduction to the fitness landscape concept, we review key
issues on evolution on simple and rugged fitness landscapes. Then we present
key modeling examples of coevolution on different fitness landscapes at
different scales, from RNA viruses to complex ecosystems and macroevolution.Comment: 40 pages, 12 figures. To appear in "Recent Advances in the Theory and
Application of Fitness Landscapes" (H. Richter and A. Engelbrecht, eds.).
Springer Series in Emergence, Complexity, and Computation, 201
The 4G/4G genotype of PAI-1 polymorphism is associated with higher plasma PAI-1 concentrations and mortality in patients with severe sepsis
Objective: Two studies have reported that patients with the 4G/4G genotype of the plasminogen activator inhibitor-1 (PAI-1) genetic polymorphism had higher plasma PAI-1 concentrations and higher risk of death than those with the 4G/5G or 5G/5G genotypes; one study involved 175 children with meningococcal disease, and the other included 88 adult patients with septic shock. Thus, the objective of this study was to determine whether there is an association between carriage of the 4G/4G genotype, plasma PAI-1 concentrations and mortality in a large series of adult septic patients. Methods: An observational, prospective, multicenter study was carried out in six Spanish Intensive Care Units including severe septic patients. We determined the PAI-1 4G/5G polymorphism and plasma PAI-1 concentrations in all patients. The end-points of the study were 30-day and 6-month mortality. Results: We included a total of 260 patients, 82 (31.5%) with 4G/4G, 126 (48.5%) with 4G/5G and 52 (20.0%) with 5G/5G genotype. Multivariate logistic regression analysis showed that the 4G/4G genotype was associated with higher mortality at 30 days (Odds Ratio = 1.95; 95% CI = 1.063-3.561; p = 0.03) and at 6 months (Odds Ratio = 2.19; 95% CI = 1.221-3.934; p = 0.01), and that higher plasma PAI-1 concentrations were associated with higher mortality at 30 days (Odds Ratio = 1.01; 95% CI = 1.002-1.022; p = 0.02) at 6 months (Odds Ratio = 1.01; 95% CI = 1.003-1.023; p = 0.01). Multivariate linear regression analysis showed that increased plasma PAI-1 concentrations were associated with the PAI-1 4G/4G genotype (regression coefficient = 4.82; 95% CI = 3.227 to 6.406; p<0.001). Conclusions: The major findings of our study, to our knowledge the largest series reporting data about 4G/5G polymorphism of the PAI-1 gene, plasma PAI-1 concentrations and mortality in septic patients, were that septic patients with the 4G/4G genotype had higher plasma PAI-1 concentrations and higher risk of death than those with 4G/5G or 5G/5G genotypes
Estudio comparativo de la fijación con o sin cemento en Prótesis Total de Rodilla
Revisamos retrospectivamente una serie de 86 pacientes portadores de 110
prótesis totales modulares de rodilla colocadas como tratamiento de la gonartrosis. Se analizan
los resultados obtenidos en los pacientes a los que se le realizó una fijación híbrida cementada
(componente femoral no cementado y componente tibial y patelar cementado) respecto a los
que se le realizó una prótesis de anclaje biológico sin ningún tipo de cementación. El análisis
de la función clínica, movilidad de la rodilla, estudio radiológico y complicaciones de ambas series
no demuestran diferencias significativas entre ambos grupos con un periodo de seguimiento
de 45 meses (r=12-60).We have retrospectively review 86 patients with 110 total knee arthroplasty for
the treatment of osteoarthrosis. We have analyzed the results obtained in a group of patients
with partial fixation with cement and another group fixated without any cement. Clinical and
radiological results and complications in both groups were similar without significant differences
with an average follow-up of 45 months (12-60)
Experiencia a medio plazo con prótesis total de rodilla semiconstreñida
Revisamos 25 prótesis totales de rodilla semiconstreñidas tipo Endo-Model Waldemar-
Link implantadas en 23 pacientes con una edad media de 69,5 años y un seguimiento medio
de 32 meses. Para la evaluación de los resultados clínicos hemos utilizado el protocolo de la Academia
Americana en el que se incluyen los parámetros de: dolor, capacidad para la marcha, facilidad
para subir y bajar escaleras, necesidad o no de bastones y flexoextensión de la articulación,
tanto antes como después de la intervención. Asimismo hemos realizado un estudio radiológico de
las prótesis en el que se ha valorado el centraje de los componentes protésicos en dos planos AP y
L y las imágenes líticas periprotésicas. Los resultados obtenidos han sido satisfactorios observando
en la totalidad de los pacientes una disminución del dolor y un aumento de su capacidad funcional.
En ningún caso se han observado infecciones profundas de la prótesis. Se ha comprobado un
aumento en el arco de flexión en las prótesis en que la punta del vástago femoral estaba desviada
hacia la cortical anterior, sin que esto se acompañase de un déficit en la extensión.We have reviewed 25 total knee prosthesis (Endo-Model type, Waldemar-Link) performed
in 23 patients with an age average of 69,5 years-old and a average follow-up of 32 months.
The clinical assessment applied was the AAOS protocol including the parameters of: pain, ability to go
up and down the stairs, to need of sticks, flexion and extension of the joint, before and after the operation.
In the radiological study we have evaluated the correct alignment of the components in two
planes A-P and L, and the periprosthetic lucencies. The results obtained have been satisfying in all the
patients with a diminution of the pain and better function of the joint. No deep infection was observed
and the flexion was better in prosthesis with anterior deviation of the femoral rod in the lateral plane
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