Evaluación in vitro de la eficacia de plaquetas convencionales, atemperadas y congeladas. Posible empleo en el medio militar / In vitro evaluation of the efficacy of fresh, temperatured and frozen platelets. Possible employment in the military environment

Introducción: La hemorragia exanguinante es la primera causa de muerte prevenible del combatiente en los conflictos armados, convirtiendo así la posibilidad de transfundir hemocomponentes de manera precoz en una prestación absolutamente fundamental durante la asistencia sanitaria a las bajas generadas en las operaciones militares. A lo largo de los numerosos conflictos acontecidos durante el pasado siglo, se han producido importantes cambios en el tratamiento hemoterápico a las bajas junto con una evolución de la doctrina sanitaria respecto a este tema. En algunos protocolos de transfusión masiva se ha empleado la técnica diagnóstica de la tromboelastometría (TE). La TE es una prueba que muestra las propiedades viscoelásticas de la sangre desde la formación del coágulo hasta su fibrinólisis, evalúa la función plaquetaria y se correlaciona con el proceso fisiológico de la hemostasia de una forma rápida. El objetivo principal de este estudio es evaluar in vitro la capacidad hemostática de los diversos concentrados de plaquetas frías, congeladas y frescas mediante pruebas de coagulación estandarizadas y tromboelastometría, esclareciendo si se mejora significativamente la contribución al coágulo con los pool de plaquetas frías (conservadas a 4ºC), en comparación con las plaquetas frescas y congeladas. También se pretende determinar qué ventajas supondría la incorporación de las plaquetas frías en la medicina transfusional realizada en el medio militar. Material y método: Se diseñó un estudio experimental para comparar in vitro plaquetas frías (refrigeradas), congeladas y frescas (convencionales), analizando su rendimiento y efectividad mediante análisis sistemático de sangre, mecanismos de laboratorio de coagulación rutinarios (Tiempo de Protrombina, Actividad de Protrombina, Tiempo de Cefalina y Fibrinógeno) y Tromboelastometría rotacional (ROTEM)...(AU)

Introduction: Exsanguinating hemorrhage is the first preventable cause of death for combatants in armed conflicts, thus making the possibility of transfusing blood components early an absolutely essential benefit during health care for casualties generated in military operations. Throughout the numerous conflicts that have occurred during the past century, there have been important changes in the hemotherapy treatment of casualties along with an evolution of the health doctrine regarding this issue. In some massive transfusion protocols, the diagnostic technique of thromboelastometry (TE) has been used. TE is a test that shows the viscoelastic properties of blood from clot formation to fibrinolysis, evaluates platelet function and correlates quickly with the physiological process of hemostasis. The main objective of this study is the evaluation in vitro of the hemostatic capacity of the various cold, frozen and fresh platelet concentrates through standardized coagulation tests and thromboelastometry, clarifying whether the contribution to the clot is significantly improved with cold platelet pools (preserved at 4ºC), compared to fresh and frozen platelets. It is also intended to determine what advantages would be the incorporation of cold platelets in transfusion medicine performed in the military environment. Material and methods: An experimental study was designed to compare cold (refrigerated), frozen and fresh (conventional) platelets in vitro, analyzing their performance and effectiveness through systematic blood analysis, routine laboratory coagulation mechanisms (Prothrombin Time, Prothrombin Activity, Cephalin and Fibrinogen) and Rotational Thromboelastometry (ROTEM).A sample of 20 healthy patients was recruited, after informing them in writing and obtaining the mandatory informed consent, they donated 6 tubes with 10 ml citrate. of blood per patient...(AU)

Multiwavelength analysis of the variability of the blazar 3C 273.

We present multiwavelength light curves and polarimetric data of the Flat Spectrum Radio Quasar 3C 273 over 8 yr. The wavelength range of our data set extends from radio to gamma-rays. We found that the optical emission in this source is dominated by the accretion disc during the entire time-frame of study. We additionally find that in contrast with the observed behaviour in other blazars, 3C 273 does not show a correlation between the gamma-ray spectral index and the gamma-ray luminosity. Finally, we identified an anticorrelation between the 15 GHz and V-band light curves for the time-range JD 245 = 4860-5760, which we speculate is the consequence of the inner part of the accretion disc falling into the black hole, followed by the ejection of a component into the jet.

North Atlantic Subtropical Gyre: SOFAR Floats Tracked by Moored Listening Stations.

In 1980, SOFAR (sound fixing and ranging) floats were tracked acoustically in the western North Atlantic entirely by means of moored autonomous listening stations. During a 5-month period 17 float trajectories were obtained in the eastern (45 degrees to 65 degrees W) Gulf Stream and subtropical gyre interior at depths of 700 and 2000 meters. These mid-depth trajectories suggest a time-varying Gulf Stream with instances of both a narrow, swift, westward recirculation south of the stream and a northeastward penetration into the Newfoundland Basin. A hundredfold increase of eddy kinetic energy was observed at 2000 meters from the gyre interior (south of 30 degrees N) to the Gulf Stream.