Characterisation and calibration of a scintillating fibre detector with > 4000 multi-anode photomultiplier channels

In the Kaos spectrometer at the Mainz Microtron a high-resolution coordinate detector for high-energy particles is operated. It consists of scintillating fibres with diameters of 4000 multi-anode photomultiplier channels. It is one of the most modern focal-plane detectors for magnetic spectrometers world-wide. To correct variations in the detection efficiency, caused by the different gains and the different optical transmittances, a fully automated off-line calibration procedure has been developed. The process includes the positioning of a radioisotope source alongside the detector plane and the automated acquisition and analysis of the detector signals. It was possible to characterise and calibrate each individual fibre channel with a low degree of human interaction.Comment: Nucl. Instrum. Meth. A (2012

El cotilo de impactación en las artroplastias de cadera

Entre los diferentes sistemas de fijación de la cúpula acetabular entre las artroplastias no cementadas, la impactación tiene múltiples ventajas. Permite un mejor contacto entre implante y hueso y no necesita destrucción de la superficie ósea receptora. Los nuevos diseños para impactación están fabricados en aleaciones de titanio y poseen una superficie rugosa recubierta a su vez con hidroxiapatita. Algunos modelos como la artroplatia Bihapro poseen aletas estabilizadoras en su reborde externo para evitar la movilización rotatoria inicial. El sistema de impactación está mostrando buenos resultados de la experiencia conocida y aunque los periodos de seguimiento son aún cortos, la integración ósea conseguida es satisfactoria. Se presentan los resultados de 1107 cúpulas Bihapro con una evolución entre uno y siete años, que han seguido un protocolo de seguimiento informatizado. En sólo un caso se presentó movilización del componente que precisó cirugía de revisión.The acetabular fixation by impaction has advantages on other systems of fixing in the cementless arthroplaties of the hip. Permit a better contact between implant and bone and it does not need destruction of the receiving bony surface. The new designs for fixation by impaction are manufactured in titanium alloys and possess a rugged surface cover at the same time with hyrdoxiapatite-coated. Some models as the arthroplasty Bihapro possess fins for primary stability in your external curbing to avoid the initial rotary mobilization. This system of fixation is showing good results in the known experience and though the periods of follow-up are yet short, the obtained bony integration is satisfactory. We presented the results of 117 Bihapro cups implanted with a follow-up from one to seven years, that they have followed a computed protocol. In only a case was presented loosening of the component that specified review surgery

Comparisons in Performance of Electromagnet and Permanent-Magnet Cylindrical Hall-Effect Thrusters

Three different low-power cylindrical Hall thrusters, which more readily lend themselves to miniaturization and low-power operation than a conventional (annular) Hall thruster, are compared to evaluate the propulsive performance of each. One thruster uses electromagnet coils to produce the magnetic field within the discharge channel while the others use permanent magnets, promising power reduction relative to the electromagnet thruster. A magnetic screen is added to the permanent magnet thruster to improve performance by keeping the magnetic field from expanding into space beyond the exit of the thruster. The combined dataset spans a power range from 50-350 W. The thrust levels over this range were 1.3-7.3 mN, with thruster efficiencies and specific impulses spanning 3.5-28.7% and 400-1940 s, respectively. The efficiency is generally higher for the permanent magnet thruster with the magnetic screen, while That thruster s specific impulse as a function of discharge voltage is comparable to the electromagnet thruster

in vivo toxicity of the ribosome-inactivating lectin ebulin f in elderly mice

Producción CientíficaEbulin f is a ribosome-inactivating protein (RIP) present in green fruits of the dwarf elder (Sambucus ebulus L). Since dwarf elder fruits are used for food and as a medicine, we assessed the study of toxicological effects and safety of ebulin f in elderly mice, comparing these results with those reported in young animals and with other RIPs. Female Swiss mice aged 6 and 12 months of age were intraperitoneally injected with a single dose from 1.4 to 4.5 mg/kg ebulin f. Heart, stomach, intestines, lung, kidney, liver, spleen, pancreas, adrenal gland, uterus, ovary and brain were studied. Histology analysis was carried out by staining with hematoxylin and eosin and Masson's trichrome observed with a light microscope, or apoptosis detection by TUNEL method observed with a confocal laser microscope. Treated animals injected with the lower dose could recover their weights, but after 14 days half of them died. The higher dose caused a progressive loss of body weight leading to death. In the animals of the experimental groups it was found atrophy of Lieberkühn's crypts, pneumonia, nephronal degeneration, myocardial atrophy, centrolobular hepatic necrosis, splenic white pulp necrosis foci and increased rate of apoptosis in the intestines and liver, in which apoptoses were mainly located in the vicinity of the lobular central vein. We conclude that ebulin f affects vital organs in elderly mice.UVa-GIR Inmunotoxinas AntitumoralesUCM-CAM Research group 95024

Osteonecrosis del platillo tibial interno: A propósito de dos casos

Presentamos dos casos de osteonecrosis idiomática del platillo tibial interno que aparecieron en mujeres. En ellas se dieron las características clínicas habituales de la enfermedad (inicio súbito de dolor intenso en rodilla sin traumatismo previo claramente diferenciado y marcada sensibilidad local en la zona interna de la rodilla) junto a radiografías iniciales normales ó con leves cambios degenerativos (gammagrafía ósea y/ó resonancia magnética nuclear.) En las dos pacientes el proceso evolucionó hacia una gonalgia intensa resistente a la medicación y con cambios degenerativos asociados y fue necesaria la implantación de sendas artroplastias totales de rodilla.We report two cases of osteonocrosis of the medial tibial plateau with typical symptoms (sudden onset of pain at the knee, and marked tenderness over the medial tibial plateau). Initial roentgenograms are within normal limits or showed mild degenerative joint changes, being necessary a magnetic resonance imaging to achieve a diagnosis. The two cases we report didn't follow the typical evolution of the process (which is self-limiting in a period of 6 to 12 months), being necessary in both of them, a total knee replacement

Liberación de la patela en las artroplastias totales de rodilla: estudio gammagráfico

Se han realizado estudios gammagráficos en 20 pacientes intervenidos de artroplastia total cementada de rodilla. En 10 casos fue necesaria la liberación del alerón rotuliano externo y en otros 10 no se había indicado dicho gesto quirúrgico. En ningún paciente existía alteración evolutiva del aparato extensor. Los estudios gammagráficos se practicaron a los 12 meses del implante con el objeto de valorar la situación vascular de la rótula en ese momento. Se comparó, en la proyección lateral, la captación de la rótula en relación a la metáfisis distal del fémur homolateral. No hemos encontrado diferencias entre ambos grupos por lo que consideramos que la liberación patelar no produce un déficit vascular rotuliano a los 12 meses de la cirugía.Scintigraphic studies were performed in 20 patients with cemented total prosthesis of the knee. The patellar release was necessary in 10 cases. None of the patients developed knee extension deficits. Scintigraphic studies were performed 12 months after surgery in order to know the patellar blood supply at that moment. Patellar isotopic uptake was compared with the uptake at the distal metaphysis of the homolateral femur, at lateral projection. We haven't found any differences between both groups, so we consider that the patellar release doesn't make a less blood supply twelve months after surgery

Dominance of the planktonic diatom Thalassiosira minima in recent summers in the Bahia Blanca Estuary, Argentina

The diatom Thalassiosira minima was first recorded in the Baha Blanca Estuary in 1992. In 19921993 it exhibited a broad seasonal occurrence. A recent survey (20062007) showed a seasonal appearance restricted mainly to summer together with a greater relative abundance within the phytoplankton. A close connection was found with warmer, more saline and highly turbid conditions experienced in recent summers in the estuary. Whether these changes will impact the estuary trophic dynamics remains an open question