Multifractal analysis application to the study of fat and its infiltration in Iberian ham: Influence of racial and feeding factors and type of slicing.

This paper explores the multifractal features of different commercial designations of Iberian ham (acorn 100% Iberian ham, acorn Iberian ham, feed/pasture Iberian ham and feed Iberian ham). This study has been done by taking as input the fatty infiltration patterns obtained from digital image analysis of ham cuts comparing mechanic and manual slicing. The yielded results show the multifractal nature of fatty connective tissue in Iberian ham, only when knife cutting is applied, confirming the differences between the designations according to their genetics and feeding. Thus, the multifractal parameters presented in this work could be considered as additional information for checking Iberian ham quality by using non-destructive methods based on the combination of image analysis and predictive techniques. Meat industry can take advantage of these methods to evaluate meat products, especially when fat-connective tissue with complex pattern distribution is involved.

Mortalidad de la cirugía coronaria aislada en octogenarios. Análisis restrospectivo de 14 años / Mortality in isolated coronary artery bypass surgery in elderly patients. A retrospective analysis over 14 years

Introducción. El objetivo de este estudio es describir nuestra experiencia en la cirugía de revascularización coronaria aislada en pacientes mayores de 80 años e identificar los riesgos específicos y predictores de mortalidad precoz. Material y métodos. Entre enero de 1999 y junio de 2013, 3.097 pacientes fueron sometidos a cirugía de revascularización coronaria aislada. Se analizaron los pacientes mayores de 80 años de edad. Se realizó una regresión mutivariante de Cox para predictores de mortalidad. Resultados. Se identificaron 99 pacientes mayores de 80 años (grupo-80; edad media 82±3,5 años) y 2.957 menores de 80 años (grupo control; edad media 64,2±9,7 años). El EuroSCORE aditivo fue 8,4±4,8 y 4,6±4,6 (p<0,001) en los>80 años vs.<80 años, respectivamente. La cirugía sin CEC se realizó en el 79,6% en el grupo-80 años. La mortalidad a los 30 días en el grupo-80 fue significativamente superior, del 11,2 vs. 3,3% (p<0,001). El grupo-80 se reintervino por sangrado más frecuentemente (9,2 vs. 2,9%; p=0,001) y tuvieron con mayor frecuencia complicaciones cardiovasculares mayores (6,1 vs. 2,1%; p=0,001). Los predictores independientes de mortalidad a 30 días fueron: la reintervención por sangrado (HR 5,7; IC 95% 1,6-19,5) y las complicaciones cardiovasculares mayores (HR 3,7; IC 95% 1,1-12,2). El seguimiento medio del grupo-80 fue de 6,3±4,2 años, con una supervivencia acumulada de estos pacientes del 65,7% durante el periodo de estudio. Conclusión. La cirugía de revascularización coronaria aislada se realiza preferentemente en pacientes mayores de 80 años sin CEC. Presentan una mayor incidencia de complicaciones cardiovasculares, reintervenciones por sangrado en el postoperatorio inmediato y una mortalidad más elevada (AU)

Introduction. We aim to describe our experience in coronary artery bypass graft in elderly patients older than 80 years and assess the associated risk and predictors of mortality in this subgroup. Material and method. From January 1999 to June 2013, 3097 patients underwent consecutive coronary artery bypass graft surgery. Patients aged over 80 years were identified. Multivariate survival analysis using Cox's regression model was performed. Results. We identified 99 patients older than 80 years (80-group; mean age 82±3.5 years) and 2957 younger than 80 years (control group) (mean age 64.2±9.7 years). Additive EuroSCORE was 8.4±4.8 and 4.6±4.6 (P<.001) in the 80-group vs. control group, respectively. Off-pump coronary artery bypass graft was performed in 79.6 vs. 41.6% (P<.001) in the 80-group vs. the control group. respectively. There was significantly higher 30 day-mortality in the 80-group, 11.2 vs. 3.3%, respectively (P<.001). Patients in the 80-group underwent reintervention for bleeding more frequently (9.2 vs. 2.9%; P=.001) and had a higher incidence of major cardiovascular complications than the control group (6.1 vs. 2.1%; P=.001). Independent predictors of mortality for the 80-group were: reoperation for bleeding (HR 5.7; 95% CI 1.6-19.5) and cardiovascular complications (HR 3.7; 95% CI 1.1-12.2). The mean follow-up was 6.3±4.2 years for the octogenarian group. The cumulative survival of these patients was 65.7% during the study period. Conclusion. Coronary artery bypass graft is performed preferably in patients over 80 years old under the off-pump procedure. Mortality is higher in this group of patients probably related to a higher incidence of cardiovascular complications and reintervention for bleeding in the immediate postoperative period (AU)

Mortality in isolated coronary artery bypass surgery in elderly patients. A retrospective analysis over 14 years. / Mortalidad de la cirugía coronaria aislada en octogenarios. Análisis restrospectivo de 14 años.

INTRODUCTION: We aim to describe our experience in coronary artery bypass graft in elderly patients older than 80 years and assess the associated risk and predictors of mortality in this subgroup. MATERIAL AND METHOD: From January 1999 to June 2013, 3097 patients underwent consecutive coronary artery bypass graft surgery. Patients aged over 80 years were identified. Multivariate survival analysis using Cox's regression model was performed. RESULTS: We identified 99 patients older than 80 years (80-group; mean age 82±3.5 years) and 2957 younger than 80 years (control group) (mean age 64.2±9.7 years). Additive EuroSCORE was 8.4±4.8 and 4.6±4.6 (P<.001) in the 80-group vs. control group, respectively. Off-pump coronary artery bypass graft was performed in 79.6 vs. 41.6% (P<.001) in the 80-group vs. the control group. respectively. There was significantly higher 30 day-mortality in the 80-group, 11.2 vs. 3.3%, respectively (P<.001). Patients in the 80-group underwent reintervention for bleeding more frequently (9.2 vs. 2.9%; P=.001) and had a higher incidence of major cardiovascular complications than the control group (6.1 vs. 2.1%; P=.001). Independent predictors of mortality for the 80-group were: reoperation for bleeding (HR 5.7; 95% CI 1.6-19.5) and cardiovascular complications (HR 3.7; 95% CI 1.1-12.2). The mean follow-up was 6.3±4.2 years for the octogenarian group. The cumulative survival of these patients was 65.7% during the study period. CONCLUSION: Coronary artery bypass graft is performed preferably in patients over 80 years old under the off-pump procedure. Mortality is higher in this group of patients probably related to a higher incidence of cardiovascular complications and reintervention for bleeding in the immediate postoperative period.

Hiperlactatemia en la ablación quirúrgica de la fibrilación auricular y cirugía cardiaca. ¿Es un factor predictivo de morbimortalidad posoperatoria? / Hyperlactatemia in surgical ablation of atrial fibrillation and cardiac surgery. Is it a predictive factor of postoperative morbidity?

Introducción: La elevación del lactato sérico en el posoperatorio de la cirugía cardiaca es frecuente y su etiopatogenia, multifactorial. Esta elevación se asocia a hipoxia tisular (hiperlactatemia tipo A) y a alteraciones metabólicas no hipóxicas (hiperlactatemia tipo B). El objetivo de este estudio fue evaluar la evolución del lactato en el posoperatorio de la ablación de la fibrilación auricular durante la cirugía valvular cardiaca y analizar si los niveles de lactato pudieran ser predictores de morbimortalidad. Material y métodos: Estudio de casos y controles. Se estudiaron 32 pacientes intervenidos entre 2011 y 2012 de ablación de la fibrilación auricular realizada junto a la cirugía de recambio valvular (grupo Maze), y 32 pacientes pareados (grupo Control). Se analizaron los niveles posoperatorios seriados de lactato, la morbimortalidad perioperatoria y la estancia hospitalaria. Se realizó un estudio univariante y multivariante para estancias prolongadas y un suceso compuesto de morbimortalidad con el fin de detectar predictores independientes. Resultados: El lactato estuvo más elevado a las 6, 12 y 24 h en el grupo Maze. En el análisis univariante resultaron significativos como predictores de complicaciones, mortalidad y estancias prolongadas el hecho de pertenecer al grupo Maze (OR 3,88; IC 95% 1,3-11,1; p = 0,01) y la elevación de lactato a las 12 h (OR 1,33; IC 95% 1,01-1,7; p = 0,04). En el análisis multivariante la pertenencia al grupo Maze fue predictor independiente de complicaciones mayores (OR 4,13; IC 95% 1,3-12,9; p = 0,015), para el suceso compuesto de morbimortalidad (OR 3,9; IC 95% 1,3-11,6; p = 0,01) y para estancia prolongada en la Unidad de Cuidados Críticos (OR 5,7; IC 95% 2,01-15,7; p = 0,01). Conclusiones: La cirugía de ablación de la fibrilación auricular podría ser una causa no descrita previamente de hiperlactatemia tipo B con picos entre las 4-24 h tras cirugía cardiaca. El valor predictivo de esta elevación, su correlación con la morbimortalidad, su sensibilidad y su especificidad para discriminar los umbrales significativos están aún por definir (AU)

Introduction: Increased serum lactate in postoperative cardiac surgery is very common and its pathogenesis is due to multiple factors. The elevation of serum lactate is associated with tissue hypoxia (hyperlactatemia type A) and non-hypoxic (hyperlactatemia type B) metabolic disorders. The aim of the study was to assess the evolution of postoperative lactate in surgical atrial fibrillation ablation during cardiac surgery, and to determine whether lactate levels could be predictors of morbimortality. Material and methods: A case-control study was conducted on 32 patients undergoing surgical atrial fibrillation ablation and cardiac surgery (Maze group) and 32 matched patients (Control group), operated on between 2011 and 2012. An analysis was made of the levels of postoperative lactate, perioperative morbimortality and hospital length of stay. A univariate and multivariate study was performed for a composite endpoint of morbimortality, and prolonged length of stay. Results: Lactate levels were significantly higher at 6, 12 and 24h in the Maze group. The univariate analysis showed that being in the Maze group (OR 3.88; 95% CI 1.3-11.1; P=.01) and an elevated lactate at 12h (OR 1.33; 95% CI 1.01-1.7; P=.04) were significant predictors of major complications, mortality, and longer hospital stays. In the multivariate analysis, surgical atrial fibrillation ablation (Maze group) was an independent predictor of major complications (OR 4.13; 95% CI 1.312.9; P=.015) for the morbimortality composite endpoint (OR 3.9; 95% CI 1.3-11.6; P=.01), and prolonged length of stay in the Intensive Care Unit (OR 5.7; 95% CI 2.01-15.7; P=.01). Conclusions: The atrial fibrillation surgical ablation may be a not-yet-described cause of type B hyperlactatemia, with serum peak values being reached between 4-24h after cardiac surgery. The predictive value of this elevation, its correlation with morbimortality, its sensitivity and specificity to discriminate the significant thresholds needs to be defined

[Hyperlactatemia in surgical ablation of atrial fibrillation and cardiac surgery. Is it a predictive factor of postoperative morbidity?]. / Hiperlactatemia en la ablación quirúrgica de la fibrilación auricular y cirugía cardiaca. ¿Es un factor predictivo de morbimortalidad posoperatoria?

INTRODUCTION: Increased serum lactate in postoperative cardiac surgery is very common and its pathogenesis is due to multiple factors. The elevation of serum lactate is associated with tissue hypoxia (hyperlactatemia type A) and non-hypoxic (hyperlactatemia type B) metabolic disorders. The aim of the study was to assess the evolution of postoperative lactate in surgical atrial fibrillation ablation during cardiac surgery, and to determine whether lactate levels could be predictors of morbimortality. MATERIAL AND METHODS: A case-control study was conducted on 32 patients undergoing surgical atrial fibrillation ablation and cardiac surgery (Maze group) and 32 matched patients (Control group), operated on between 2011 and 2012. An analysis was made of the levels of postoperative lactate, perioperative morbimortality and hospital length of stay. A univariate and multivariate study was performed for a composite endpoint of morbimortality, and prolonged length of stay. RESULTS: Lactate levels were significantly higher at 6, 12 and 24h in the Maze group. The univariate analysis showed that being in the Maze group (OR 3.88; 95% CI 1.3-11.1; P=.01) and an elevated lactate at 12h (OR 1.33; 95% CI 1.01-1.7; P=.04) were significant predictors of major complications, mortality, and longer hospital stays. In the multivariate analysis, surgical atrial fibrillation ablation (Maze group) was an independent predictor of major complications (OR 4.13; 95% CI 1.312.9; P=.015) for the morbimortality composite endpoint (OR 3.9; 95% CI 1.3-11.6; P=.01), and prolonged length of stay in the Intensive Care Unit (OR 5.7; 95% CI 2.01-15.7; P=.01). CONCLUSIONS: The atrial fibrillation surgical ablation may be a not-yet-described cause of type B hyperlactatemia, with serum peak values being reached between 4-24h after cardiac surgery. The predictive value of this elevation, its correlation with morbimortality, its sensitivity and specificity to discriminate the significant thresholds needs to be defined.

Multifractal analysis of validated wind speed time series.

Multifractal properties of 30 min wind data series recorded at six locations in Cadiz (Southern Spain) have been studied in this work with the aim of obtaining detailed information for a range of time scales. Wind speed records have been validated, applying various quality control tests as a pre-requisite before their use, improving the reliability of the results due to the identification of incorrect values which have been discarded in the analysis. The scaling of the wind speed moments has been analysed and empirical moments scaling exponent functions K(q) have been obtained. Although the same critical moment (qcrit) has been obtained for all the places, some differences appear in other multifractal parameters like γmax and the value of K(0). These differences have been related to the presence of extreme events and zero data values in the data series analysed, respectively.

Atrial Fibrillation and Stroke Risk After Coronary Artery Bypass Grafting Surgery.

Background: The present multicentre study was aimed at determining the effect of preoperative atrial fibrillation (preop-AF) as stroke risk factor in coronary artery bypass graft surgery (CABG) during the perioperative period. Methods: Patients undergoing isolated CABG surgery were enrolled from 21 Spanish centers. Baseline variables related with perioperative stroke risk were recorded and analysed. The Northern New England Cardiovascular Disease Study Group (NNECVDSG) stroke risk schema was used to stratify stroke risk and compare predicted vs observed neurologic outcomes in this study. Results: 26347 patients were enrolled in the study. Prevalence of preop-AF was 4.2%, and was associated significantly with major cardiovascular comorbidities. The stroke rate was 1.38% (365 strokes), and it was slightly higher for patients with preop-AF vs non preop-AF, 1.82% vs 1.36%, p = 0.2. NNECVDSG schema showed good predictive ability calculating the area under the receiver operating characteristic curve (c-statistic 0.696; 95% CI 0.668 to 0.723). To investigate the associations of baseline preoperative variables with perioperative CABG-stroke a logistic regression model was performed. Preop-AF impact on perioperative stroke was lower that other variables. Preop-AF did not show an adverse impact in the quartiles groups according to NNECVDSG Stroke Risk Index. Conclusion: Risk of perioperative stroke in isolated CABG surgery patients is not significantly increased by preop-AF.

Evaluation of the temporal scaling variability in forecasting ground-level ozone concentrations obtained from multiple linear regressions.

Ozone is a highly unpredictable pollutant which severely affects living conditions in urban and surrounding areas in the Mediterranean basin. This secondary pollutant periodically reaches extremely high concentrations, damaging human health. Multiple linear regression has been widely used in previous works due to the fact that it is a simple and versatile method for forecasting ozone concentrations. However, these models usually prove their validity using fulfillment of statistical constraints, ignoring other intrinsic characteristics existing in the time series, such as the temporal scaling behavior and the data distribution over different time scales. In previous works, it has been demonstrated that observed ozone time series are of a multifractal nature, meaning that the data distribution can be described by using the multifractal spectrum. This work focuses on the capacity of a forecasting model to reproduce the scaling features existing in an observed time series when several chemical and meteorological explanatory variables are introduced following the stepwise procedure. A comparison between the observed spectrum and the simulated ones for each step is used to check which explanatory variables better reproduce the multifractal nature in real ozone time series. It has been confirmed that a model with few explanatory variables allows reproducing the multifractal nature in the simulated time series with an acceptable accuracy without compromising the values of the coefficient of determination and root-mean-squared error, which were used as performance indicators.

Multifractal analysis application to the characterization of fatty infiltration in Iberian and White pork sirloins.

This paper applies the multifractal analysis based on the sandbox method to describe the distribution of fatty infiltration in Iberian and White pork meat with the aim of characterization and classification. This work was carried out by making photographs of sirloin cuts of both breeds and then treated with image analysis software. The obtained image data were stored in text format and constituted the input for multifractal analysis. The results obtained show that pork sirloin connective fatty tissue exhibits a multifractal type of scaling. Significant correlations were found between some of the parameters governing the multifractal behavior and fat percentage, especially in the case of Iberian sirloin. The differences found for the relationships between the generalized fractal dimensions and fat percentage provide information for the categorization of the studied meat pieces.

Vulnerability for reentry in a three dimensional model of human atria: a simulation study.

Atrial tachycardias are the most common cardiac arrhythmias in clinical practice, which induce changes in atrial properties that help to perpetuate them. These changes are called "atrial remodeling". Recent studies have shown that rapid ectopic activity principally on the pulmonary veins can trigger reentrant mechanisms and lead to atrial tachycardias. However, the influences of ectopic foci location, the number of ectopic beats and its frequency on the likelihood of triggering reentries are not well known. In this work the effects of electrical remodeling were incorporated in an atrial cell model and integrated in a three-dimensional model of human atria, to develop a study of vulnerability for reentries. To carry out the study, an ectopic beat and a burst of six ectopic beats at two different frequencies were applied in six different locations in the atria. The results show greater vulnerability in the left pulmonary veins when we applied a single ectopic beat. When we increase the number of ectopic beats to six, a greater width of the vulnerable window was observed when ectopic focus frequency was high. The location, the number of ectopic beats and their frequency affect the vulnerability for reentry.

Description of the seasonal pattern in ozone concentration time series by using the strange attractor multifractal formalism.

Ozone is a secondary pollutant that, at high concentrations in urban environment, affects human health. Thus, suitable knowledge of ozone dynamics is essential for avoiding undesirable effects on the population. Ten-minute ozone concentration time series recorded at Córdoba (southern Spain) in 2007, for January, April, July and October, have been analysed by using the strange attractor multifractal formalism with the aim of describing the seasonal pattern of this pollutant. The multifractal nature of ozone concentration was detected in a study of the mass exponent functions for autumn-winter and spring-summer seasons. Multifractal spectra showed a greater heterogeneity in the low values of the time series. The presence of rare values in ozone data sets was also investigated, showing that the multifractal approach provided considerable detailed information on the time series structure that completes the statistical descriptive analysis.

Long-term storage in liquid nitrogen does not affect cell viability in cardiac valve allografts.

Liquid nitrogen is the most common medium used by tissue banks for the storage of cryopreserved heart valves. This study evaluates the effect of the length of storage on human cryopreserved heart valves. Human tissues (14 aortic and 13 pulmonary) were frozen in a controlled-rate freezer (1 degrees C/min) and stored in the liquid phase of a nitrogen tank for 9.1+/-1.6 years. The preservative solution was medium M199 containing 5% human serum albumin and 10% Me(2)SO. After thawing in a water bath at 42 degrees C, the cryoprotectant was removed. Then, fragments from vascular wall and leaflet were dissected. Explant cultures and histological studies were performed in order to assess cell viability and structural integrity. CD90 and CD31 expression was analysed in cultured cells using flow cytometry. Light microscopy, immunofluorescence staining and laser scanning confocal microscopy were used to evaluate cell viability and extracellular matrix components. Electron microscopy was used for ultrastructural study. Cell cultures could be obtained from all the specimens assayed. Cells grew from explants showing a fibroblastic phenotype. CD90 expression was common in cultured cells but a low percentage of cells expressed CD31. Histological results showed a good preservation estructure in both leaflets and vascular walls. Morphological features of cellular irreversible damage were very rare. No differences which could be due to length of allograft storage period were observed. We concluded that allografts stored in liquid nitrogen up to 13 years did not significantly undergo loss of cell viability other than that due to disinfection, freezing and thawing protocols.

[Primary cardiac hemangioma. A case report and review of the literature]. / Hemangioma cardíaco primario. Presentación de un caso y revisión de la literatura.

A 26-years-old woman, without symptoms, was diagnosed of cardiac tumor by means of two-dimensional echocardiography, magnetic resonance imaging and angiocardiography. The tumor was removed underwent open-heart operation and cardiopulmonary bypass. Histologic study was suggestive of a capillary hemangioma. We present our experience with this case and a review of the literature.