Polarimetric analysis of STEREO observations of sungrazing kreutz comet C/2010 E6 (STEREO)

Twin STEREO spacecraft pre-perihelion photometric and polarimetric observations of the sungrazing Kreutz comet C/2010 E6 (STEREO) in March 2010 at heliocentric distances 3−28 R⊙ were investigated using a newly created set of analysis routines. The comet fully disintegrated during its perihelion passage. Prior to that, a broadening and an increase of the intensity peak with decreasing heliocentric distance was accompanied by a drop to zero polarization at high phase angles (∼105°–135°, STEREO-B) and the emergence of negative polarization at low phase angles (∼25°–35°, STEREO-A). Outside the near-comet region, the tail exhibited a steep slope of increasing polarization with increasing cometocentric distance, with the slope becoming less prominent as the comet approached the Sun. The steep slope may be attributed to sublimation of refractory organic matrix and the processing of dust grains, or to presence of amorphous carbon. The change in slope with proximity to the Sun is likely caused by the gradual sublimation of all refractory material. The polarization signatures observed at both sets of phase angles closer to the comet photocentre as the comet approached the Sun are best explained by fragmentation of the nucleus, exposing fresh Mg-rich silicate particles, followed by their gradual sublimation. The need for further studies of such comets, both observational and theoretical, is highlighted, as well as the benefit of the analysis routines created for this work

Therapeutic drug monitoring of once daily aminoglycoside dosing: comparison of two methods and investigation of the optimal blood sampling strategy

Purpose: Therapeutic drug monitoring of patients receiving once daily aminoglycoside therapy can be performed using pharmacokinetic (PK) formulas or Bayesian calculations. While these methods produced comparable results, their performance has never been checked against full PK profiles. We performed a PK study in order to compare both methods and to determine the best time-points to estimate AUC0-24 and peak concentrations (C max). Methods: We obtained full PK profiles in 14 patients receiving a once daily aminoglycoside therapy. PK parameters were calculated with PKSolver using non-compartmental methods. The calculated PK parameters were then compared with parameters estimated using an algorithm based on two serum concentrations (two-point method) or the software TCIWorks (Bayesian method). Results: For tobramycin and gentamicin, AUC0-24 and C max could be reliably estimated using a first serum concentration obtained at 1h and a second one between 8 and 10h after start of the infusion. The two-point and the Bayesian method produced similar results. For amikacin, AUC0-24 could reliably be estimated by both methods. C max was underestimated by 10-20% by the two-point method and by up to 30% with a large variation by the Bayesian method. Conclusions: The ideal time-points for therapeutic drug monitoring of once daily administered aminoglycosides are 1h after start of a 30-min infusion for the first time-point and 8-10h after start of the infusion for the second time-point. Duration of the infusion and accurate registration of the time-points of blood drawing are essential for obtaining precise predictions

Long term follow up results of sequential left internal thoracic artery grafts on severe left anterior descending artery disease

<p>Abstract</p> <p>Purpose</p> <p>Several alternative procedures have been proposed to achieve complete revascularization in the presence of diffuse left anterior descending coronary artery (LAD) disease. With the extensive use of internal thoracic artery grafts in coronary artery bypass procedures, sequential anastomosis of the left internal thoracic artery (LITA) to LAD has gained popularity in these challenging cases. The long term results of sequential LITA to LAD anstomosis were examined in this study.</p> <p>Patients and Methods</p> <p>In order to determine the long term results of the sequential revascularization of LAD by LITA graft, 41 out of 49 patients operated between January 2001 and December 2005 were selected for control coronary arteriography. The median period for control coronary arteriography was 64 months.</p> <p>Results</p> <p>Seventy five anastomoses were found to be fully patent (91,46%) among the 82 sequential LITA anastomoses (41 LITA grafts) on the LAD at a median follow-up period of 64 months (53 to 123 months). Among the 41 LITA grafts used for this purpose, 36 were found intact (complete patency of the proximal and distal anastomoses) (87,8%). Two LITA grafts (4 anastomoses) were found to be totally occluded (4,87%). The proximal anastomosis of the LITA graft was observed to be 90% stenotic in one patient (1,21%). In one patient tight stenosis of the distal anastomosis line was observed (1,21%), while in another patient 70% narrowing of LITA lumen after the proximal anastomosis was detected (1,21%).</p> <p>Conclusion</p> <p>We strongly beleive that sequential LITA grafting of LAD is a safe alternative in the presence of severe LAD disease to achieve complete revascularization of the anterior myocardium with patency rates not much differing from conventional single LITA to LAD anastomosis.</p

Impact of concomitant aortic regurgitation on long-term outcome after surgical aortic valve replacement in patients with severe aortic stenosis

<p>Abstract</p> <p>Background</p> <p>Prognostic value of concomitant aprtic regurgitation (AR) in patients operated for severe aortic stenosis (AS) is not clarified. The aim of this study was to prospectively examine the impact of presence and severity of concomitant AR in patients operated for severe AS on long-term functional capacity, left ventricular (LV) function and mortality.</p> <p>Methods</p> <p>Study group consisted of 110 consecutive patients operated due to severe AS. The patients were divided into AS group (56 patients with AS without AR or with mild AR) and AS+AR group (54 patients with AS and moderate, severe or very severe AR). Follow-up included clinical examination, six minutes walk test (6MWT) and echocardiography 12 and 104 months after AVR.</p> <p>Results</p> <p>Patients in AS group had lower LV volume indices throughout the study than patients in AS+AR group. Patients in AS group did not have postoperative decrease in LV volume indices, whereas patients in AS+AR group experienced decrease in LV volume indices at 12 and 104 months. Unlike LV volume indices, LV mass index was significantly lower in both groups after 12 and 104 months as compared to preoperative values. Mean LVEF remained unchanged in both groups throughout the study. NYHA class was improved in both groups at 12 months, but at 104 months remained improved only in patients with AS. On the other hand, distance covered during 6MWT was longer at 104 months as compared to 12 months only in AS+AR group (p = 0,013), but patients in AS group walked longer at 12 months than patients in AS+AR group (p = 0,002). There were 30 deaths during study period, of which 13 (10 due to cardiovascular causes) in AS group and 17 (12 due to cardiovascular causes) in AS+AR group. Kaplan-Meier analysis showed that the survival probability was similar between the groups. Multivariate analysis identified diabetes mellitus (beta 1.78, p = 0.038) and LVEF < 45% (beta 1.92, p = 0.049) as the only independent predictor of long-term mortality.</p> <p>Conclusion</p> <p>Our data indicate that the preoperative presence and severity of concomitant AR has no influence on long-term postoperative outcome, LV function and functional capacity in patients undergoing AVR for severe AS.</p

Mantenimiento de interiores de cabina de Vueling Airlines

En el presente documento se expone un análisis de los procesos relacionados con mantenimiento de cabinas de una aerolínea y se proponen mejoras para los mismos. Se parte de un estado inicial en el que no se ejerce un mantenimiento especialmente dedicado a interiores de cabina, lo cual supone una mala imagen para la empresa. Esto repercute directamente en la satisfacción del pasajero y se ve reflejado en el NPS de la aerolínea. Además, también afecta a la comodidad de la tripulación provocando quejas continuas al respecto. Para tal de mejorar la situación, se decide emprender un nuevo proyecto cuyo objetivo principal es la mejora de los interiores de cabina a través de mantenimiento exclusivamente contratado para tal fin. Así, a través del presente proyecto se analizan tanto el mantenimiento correctivo como el preventivo, exponiendo las ventajas de cada uno y los resultados e impactos que han provocado en las cabinas. Todos los procesos utilizados en mantenimiento se verán reflejados en los mapas de flujos tipo BPMN. Al principio, la monitorización global del proyecto se realizará de manera bastante manual pero pronto se encaminará hacia la transformación digital. Cabe destacar que este estudio se realiza en colaboración con Vueling Airlines y la autora del proyecto estará integrada al recién formado departamento de interiores. A su vez, este departamento forma parte de la CAMO, situada en el hangar del aeropuerto de Barcelona. El objetivo final del proyecto es ver, mediante la evolución del NPS, si el aspecto de cabinas realmente afecta al pasajero y si vale la pena seguir invirtiendo económicamente en el mantenimiento de interiores.The present document provides an analysis of the processes related to the maintenance of an airline cabins’ and proposes some improvements. The study will start from an initial state in which there is no maintenance especially dedicated to cabin interiors, which provokes a bad image for the company. This fact has a direct impact on passenger satisfaction and is clearly reflected in the airline’s NPS. What is more, it also affects the crew’s comfort causing continuous complaints. In order to improve the situation, it is decided to start a new project whose main objective is the enhancement of cabin interiors’ aspect and functionality through a planned maintenance exclusively contracted for this purpose. Thus, through this project, both corrective and preventive types of maintenance are going to be analyzed, exposing the advantages of each and the results and impacts caused in the cabins. All processes used in maintenance will be reflected in the BPMN process flow diagrams. Initially, the overall monitoring of the project will be done fairly manually but will soon be on the way to digital transformation. It should be noted that this study is carried out in collaboration with Vueling Airlines and that the author of the project will be integrated into the newly formed cabin interiors department. This department is part of the Vueling’s CAMO, located in the hangar of the Barcelona airport. The final objective of the project is to see, through the evolution of the NPS, whether the appearance of cabins really affects the passenger and whether it is worth continuing to invest economically in the maintenance of interiors

Mantenimiento de interiores de cabina de Vueling Airlines

En el presente documento se expone un análisis de los procesos relacionados con mantenimiento de cabinas de una aerolínea y se proponen mejoras para los mismos. Se parte de un estado inicial en el que no se ejerce un mantenimiento especialmente dedicado a interiores de cabina, lo cual supone una mala imagen para la empresa. Esto repercute directamente en la satisfacción del pasajero y se ve reflejado en el NPS de la aerolínea. Además, también afecta a la comodidad de la tripulación provocando quejas continuas al respecto. Para tal de mejorar la situación, se decide emprender un nuevo proyecto cuyo objetivo principal es la mejora de los interiores de cabina a través de mantenimiento exclusivamente contratado para tal fin. Así, a través del presente proyecto se analizan tanto el mantenimiento correctivo como el preventivo, exponiendo las ventajas de cada uno y los resultados e impactos que han provocado en las cabinas. Todos los procesos utilizados en mantenimiento se verán reflejados en los mapas de flujos tipo BPMN. Al principio, la monitorización global del proyecto se realizará de manera bastante manual pero pronto se encaminará hacia la transformación digital. Cabe destacar que este estudio se realiza en colaboración con Vueling Airlines y la autora del proyecto estará integrada al recién formado departamento de interiores. A su vez, este departamento forma parte de la CAMO, situada en el hangar del aeropuerto de Barcelona. El objetivo final del proyecto es ver, mediante la evolución del NPS, si el aspecto de cabinas realmente afecta al pasajero y si vale la pena seguir invirtiendo económicamente en el mantenimiento de interiores.The present document provides an analysis of the processes related to the maintenance of an airline cabins’ and proposes some improvements. The study will start from an initial state in which there is no maintenance especially dedicated to cabin interiors, which provokes a bad image for the company. This fact has a direct impact on passenger satisfaction and is clearly reflected in the airline’s NPS. What is more, it also affects the crew’s comfort causing continuous complaints. In order to improve the situation, it is decided to start a new project whose main objective is the enhancement of cabin interiors’ aspect and functionality through a planned maintenance exclusively contracted for this purpose. Thus, through this project, both corrective and preventive types of maintenance are going to be analyzed, exposing the advantages of each and the results and impacts caused in the cabins. All processes used in maintenance will be reflected in the BPMN process flow diagrams. Initially, the overall monitoring of the project will be done fairly manually but will soon be on the way to digital transformation. It should be noted that this study is carried out in collaboration with Vueling Airlines and that the author of the project will be integrated into the newly formed cabin interiors department. This department is part of the Vueling’s CAMO, located in the hangar of the Barcelona airport. The final objective of the project is to see, through the evolution of the NPS, whether the appearance of cabins really affects the passenger and whether it is worth continuing to invest economically in the maintenance of interiors