1,315 research outputs found
Impact of goal directed therapy in head and neck oncological surgery with microsurgical reconstruction: free flap viability and complications
Background: Surgical outcomes in free flap reconstruction of head and neck defects in cancer patients have improved steadily in recent years; however, correct anaesthesia management is also important. The aim of this study has been to show whether goal directed therapy can improve flap viability and morbidity and mortality in surgical patients. Methods: we performed an observational case control study to analyse the impact of introducing a semi invasive device (Flo Trac®) during anaesthesia management to optimize fluid management. Patients were divided into two groups: one received goal directed therapy (GDT group) and the other conventional fluid management (CFM group). Our objective was to compare surgical outcomes, complications, fluid management, and length of stay between groups. Results: We recruited 140 patients. There were no differences between groups in terms of demographic data. Statistically significant differences were observed in colloid infusion (GDT 53.1% vs. CFM 74.1%, p = 0.023) and also in intraoperative and postoperative infusion of crystalloids (CFM 5.72 (4.2, 6.98) vs. GDT 3.04 (2.29, 4.11), p < 0.001), which reached statistical significance. Vasopressor infusion in the operating room (CFM 25.5% vs. GDT 74.5%, p < 0.001) and during the first postoperative 24h (CFM 40.6% vs. GDT 75%, p > 0.001) also differed. Differences were also found in length of stay in the intensive care unit (hours: CFM 58.5 (40, 110) vs. GDT 40.5 (36, 64.5), p = 0.005) and in the hospital (days: CFM 15.5 (12, 26) vs. GDT 12 (10, 19), p = 0.009). We found differences in free flap necrosis rate (CMF 37.1% vs. GDT 13.6%, p = 0.003). One-year survival did not differ between groups (CFM 95.6% vs. GDT 86.8%, p = 0.08). Conclusions: Goal directed therapy in oncological head and neck surgery improves outcomes in free flap reconstruction and also reduces length of stay in the hospital and intensive care unit, with their corresponding costs. It also appears to reduce morbidity, although these differences were not significant. Our results have shown that optimizing intraoperative fluid therapy improves postoperative morbidity and mortalit
El Videojuego. Un enfoque educativo en el área de la matemática
Documento elaborado para ser utilizado como apoyo en el trabajo docente.Con el auge en las modalidades educativas en los últimos tiempos, así como en las propuestas en el modelaje de la elaboración de nuevos materiales didácticos que apoyen el proceso de enseñanza aprendizaje, además del aporte que ofrecen las Tecnologías de la Información y la Comunicación; elementos conjuntos que demandan un cambio de fondo en el diseño de herramientas lúdicas, en cuanto a las metodologías y estrategias educativas, están dando como resultado nuevas formas de enseñar y de aprender. En este sentido, se han realizado diversas acciones para proporcionar recursos educativos, derivados del juego, que apoyen la actividad diaria de docentes-discentes. Es por ello que la propuesta de investigación va encaminada a presentar un videojuego educativo y la manera en que puede estimular el proceso enseñanza-aprendizaje. Todo lo anterior desde la perspectiva de los estilos de aprendizaje de los educandos, tomando en consideración las teorías de Gardner. Para este caso de estudio, se implementó un software denominado MALV en el área de la matemática para la resolución de ecuaciones de primer grado con una incógnita, como apoyo para alumnos de una licenciatura de la UAE
Cu-Doped KCl folded and unfolded band structure and optical properties studied by DFT calculations
We computed the optical properties and the folded and unfolded band structure
of Cu-doped KCl crystals. The calculations use the plane-wave pseudo-potential
approach implemented in the ABINIT electronic structure package within the
first-principles density-functional theory framework. Cu substitution into
pristine KCl crystals requires calculation by the supercell (SC) method from a
theoretical perspective. This procedure shrinks the Brillouin zone, resulting
in a folded band structure that is difficult to interpret. To solve this
problem and gain insight into the effect of cuprous ion (Cu+) on electronic
properties; We unfolded the band structure of SC KCl:Cu to directly compare
with the band structure of the primitive cell (PC) of pristine KCl. To
understand the effect of Cu substitution on optical absorption, we calculated
the imaginary part of the dielectric function of KCl:Cu through a
sum-over-states formalism and broke it down into different band contributions
by partially making an iterated cumulative sum (ICS) of selected valence and
conduction bands. As a result, we identified those interband transitions that
give rise to the absorption peaks due to the Cu ion. These transitions include
valence and conduction bands formed by the Cu-3d and Cu-4s electronic states.
To investigate the effects of doping position, we consider different doping
positions, where the Cu dopant occupies all the substitutional sites replacing
host K cations. Our results indicate that the doping position's effects give
rise to two octahedral shapes in the geometric structure. The distorted-twisted
octahedral square bipyramidal geometric-shape induces a difference in the
crystal field splitting energy compared to that of the perfect octahedral
square bipyramidal geometric-shape.Comment: 39 total pages, 30 article, and 9 references. There are 19 figures
done with gnuplot high-qualit
New data on chert catchment analysis in inland Iberia during the Late Pleistocene
In this paper, we present the first results obtained after new fieldwork and laboratory studies of chert catchment sources during the Middle and Upper Palaeolithic in inland Iberia, a region that has been traditionally depicted as marginal and sparsely populated during the last glacial due to its harsh ecological conditions compared to the coastal areas of the Iberian Peninsula. Our main aim is to determine the mobility strategies and social networks of the last Neandertals and first modern humans settled in inland Iberia and neighbouring regions, and eventually test the hypothesis that the last glacial human settlement in the Iberian hinterland was more dense and complex than previously thought. In this study, we focus on the cherts exploited at two archaeological sites: the Peña Cabra and Peña Capón rock shelters. These sites are located in the southeastern foothills of the Central System range, in the province of Guadalajara (Spain), and they have yielded a sequence of human occupations from the Middle and Upper Palaeolithic, respectively. To obtain a detailed picture of the mobility patterns and catchment strategies of the hunter-gatherers settled at these sites, our fieldwork focussed on identifying chert outcrops that could have been frequented and exploited by them. After two field seasons, 22 chert outcrops from eight geological formations were identified and more than 300 samples were collected and analysed. We conducted textural, micropalaeontological, petrographical and geochemical analyses, with the aim of comprehensively characterising the various rock resources available in the study area. Results have shown that different siliceous varieties were available in the area surrounding the sites and both Neandertals and modern humans could have provisioned there. Also, they suggest the potential existence of a network connecting the Tagus and Ebro valleys, but this is a working hypothesis to be tested with future research.European Research Council (ERC)Agencia Estatal de Investigació
Clinical Outcomes and Cost Analysis of Fibula Free Flaps: A Retrospective Comparison of CAD/CAM versus Conventional Technique
(1) Background: A decrease in operative time can not only improve patient outcomes through a reduction in the risk of developing complications but can also result in cost savings. The aim of this study is to determine whether there an intraoperative time gain can be achieved by using the preoperative virtual planning of mandibular reconstruction using a free fibula flap compared with freehand plate bending and osteotomies. (2) Methods: A retrospective comparative study was carried out in the Oral and Maxillofacial Department of La Paz University Hospital, Madrid, Spain. The study compared 18 patients in the CAD/CAM group with 19 patients in the conventional freehand group. A comparison was made between the total surgical time, the comorbidities, and the hospital stay. The resource consumption was estimated using a cost analysis. (3) Results: Although CAD/CAM was a statistically more expensive procedure in the perioperative phase, no significant differences were observed in total health care costs between the two groups. There was a non-significant trend towards an increase in complications with conventional reconstruction plates compared to patient-specific plates (PSI). (4) Conclusions: CAD/CAM technology and a 3D printed cutting guide offer a significantly shorter surgical time, which is associated with a reduction in hospital days, PACU days, and complications. The cost of CAD/CAM technology is comparable to that of the conventional freehand technique
Renal transplantation in the modern immunosuppressive era in Spain: four-year results from a multicenter database focus on post-transplant cardiovascular disease
Producción CientíficaTo evaluate cardiovascular disease (CVD) after renal transplantation we established a CVD database
(no-intervention) including all patients transplanted among 2000–2002 in 14 hospitals from Spain (Renal Forum Group) (n¼2600). They were prospective followed annually thereafter and we present herein the most important results concerning survival figures and CVD at four years. Mean recipient age was 49.7±13.7 years: 16% retransplanted and 12.5% hyperimmunized. Tacrolimus, mycophenolate
mofetil, and steroids was used in 63%. Acute rejection (AR) rate at 1 year was 14.8%. Graft and patient survival at 48 months were 85.6% (death censored) and 91.7% respectively. The first cause of graft loss was vascular in the first year, death with function during the 2–3 years, and chronic allograft nephropathy at the 4th year. Donor age, time on dialysis, acute tubular necrosis (ATN), AR, SCr at 6
months, the use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers in the first year, and systolic blood pressure at 24 months were independent risk factors for graft loss at 4th year. The first cause of death was CVD (predominantly ischemic heart disease (IHD) in the first year). Recipient age, ATN, and SCr at 6 months were independent predictors of mortality. Despite
worsening of donor age, comorbidity, and advanced age of recipients, survival figures at four years are considered good in our Spanish non-selected population. Cardiovascular mortality is the most important cause of death and graft loss particularly, IHD in the first year. Therefore, to decrease post-transplant mortality a careful cardiovascular evaluation and treatment in the waiting list and a close follow-up of patients after transplantation is mandatory
Exploring plant responses to abiotic stress by contrasting spectral signature changes
In this study, daily changes over a short period and diurnal progression of spectral reflectance at the leaf level were used to identify spring wheat genotypes (Triticum aestivum L.) susceptible to adverse conditions. Four genotypes were grown in pots experiments under semi-controlled conditions in Chile and Spain. Three treatments were applied: i) control (C), ii) water stress (WS), and iii) combined water and heat shock (WS+T). Spectral reflectance, gas exchange and chlorophyll fluorescence measurements were performed on flag leaves for three consecutive days at anthesis. High canopy temperature (HCT) genotypes showed less variability in their mean spectral reflectance signature and chlorophyll fluorescence, which was related to weaker responses to environmental fluctuations. While low canopy temperature (LCT) genotypes showed greater variability. The genotypes spectral signature changes, in accordance with environmental fluctuation, were associated with variations in their stomatal conductance under both stress conditions (WS and WS+T); LCT genotypes showed an anisohydric response compared that of HCT, which was isohydric. This approach could be used in breeding programs for screening a large number of genotypes through proximal or remote sensing tools and be a novel but simple way to identify groups of genotypes with contrasting performances
Risk factors for graft loss and mortality after renal transplantation according to recipient age: a prospective multicentre study
Producción CientíficaBackground. To describe the causes of graft loss, patient death and survival figures in kidney transplant patients in Spain based on the recipient’s age. Methods. The results at 5 years of post-transplant cardiovascular disease (CVD) patients, taken from a database on CVD, were prospectively analysed, i.e. a total of 2600 transplanted patients during 2000–2002 in 14 Spanish renal transplant units, most of them receiving their organ from cadaver donors. Patients were grouped according to the recipient’s age: Group A: 60 years. The most frequent immunosuppressive regimen included tacrolimus, mycophenolate mofetil and steroids. Results. Patients were distributed as follows: 25.85% in Group A (>40 years), 50.9% in Group B (40–60 years) and 23.19% in Group C (>60). The 5-year survival for the different age groups was 97.4, 90.8 and 77.7%, respectively. Death-censored graft survival was 88, 84.2 and 79.1%, respectively, and non death-censored graft survival was 82.1, 80.3 and 64.7%, respectively. Across all age groups, CVD and infections were the most frequent cause of death. The main causes of graft loss were chronic allograft
dysfunction in patients 1 g at 6 months post-transplantation were statistically significant in the three age groups. The patient survival multivariate analysis did not achieve a statistically significant common factor in the three age groups.
Conclusions. Five-year results show an excellent recipient survival and graft survival, especially in the youngest age group. Death with functioning graft is the leading cause of graft loss in patients >40 years. Early improvement of renal function and proteinuria together with strict control of cardiovascular
risk factors are mandatory
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