Metal-free design of a multilayered metamaterial with chirped Bragg grating for enhanced radiative cooling.

A wideband, all-dielectric metamaterial structure for enhancing radiative cooling is investigated. The structure is optimized to reflect most of the solar irradiance window (between 0.3 µm-3 µm), which is one of the biggest challenges in highly efficient radiative cooling coatings. The design is based on the principles of Bragg gratings, which constitutes a simple synthesis procedure to make a broadband reflector of reduced dimensions, without metallic layers, while keeping a flat enough response in the entire bandwidth. Numerical results show that reflection of solar irradiation can be easily tailored and maximized using this method, as well as the net cooling power of the device, about ∼79 W/m2 at daytime (about double at night-time) and a temperature reduction of 23 K (assuming no heat exchange) and 7 K assuming a heat exchange coefficient of 10 W/m2/K, for a device and ambient temperatures of 300 K and 303 K, respectively. This occurs even in detriment of absorption in the atmospheric window (8 µm-13 µm). Results also show the importance of efficiently reflecting solar irradiance for such technologies and its relevance in synthesis and design without using metallic components.

Splenic volume as a biomarker of hepatic damage after chemotherapy in patients with resected colorectal liver metastases (CRLM).

BACKGROUND: Chemotherapy-associated liver injury (CALI) is a matter of concern for hepatobiliary surgeons as it can entail postoperative liver failure after an extensive hepatectomy. Recent studies have taken special interest in liver function parameters which can correlate with CALI to decrease this adverse event. Therefore, the current study investigates the usefulness of splenic volume as a biomarker of CALI through a portal hypertension mechanism, in patients with colorectal liver metastases (CRLM). STUDY DESIGN: We carried out a study in patients with CRLM operated on between 2009 and 2014 in our center. All samples of healthy liver were graded for non-alcoholic fatty liver disease (NAFLD) and sinusoidal obstructive syndrome. Computarized tomography scans for spleen volumetry were analyzed for each patient at CRLM diagnosis, after neoadjuvant chemotherapy, 1 and 6 months after resection. RESULTS: A group of 65 consecutive patients with CRLM of large bowel adenocarcinoma submitted to liver resection were included. Patients receiving neoadjuvant chemotherapy had a greater spleen volume increase than those who did not receive treatment (p = 0.053), finding a statistically significant spleen growth in patients with NAFLD (p = 0.036). There was no correlation between spleen enlargement and postoperative complications or average stay. However, survival was decreased in patients with spleen growth and CALI. CONCLUSIONS: Patients who receive neoadjuvant chemotherapy for liver metastasis surgery have a greater splenic volume increase, which correlates with NAFLD and a lower survival.

Bariatric Surgery Waiting Lists in Spain.

Bariatric surgery is one of the most common general surgery procedures in countries that, like Spain, have public healthcare systems, but is also one of the procedures for which patients have to wait the longest. The Spanish Society of Obesity Surgery (SECO) conducted a survey to estimate the situation of bariatric surgery waiting lists in Spain's public hospitals and to gather information on a number of related aspects. METHODS: An online survey was sent to the members of the SECO. The survey received 137 visits, all via the click-through link provided, from 52 health centers (47 public and 5 private). The data collected were included in a database and later analyzed using the SPSS18.0 statistical software package. RESULTS: A total of 4724 patients were on bariatric surgery waiting lists (BWLs), at an average of 100 per public hospital. Sixty-eight percent had been waiting for more than 6 months. The mean delay per patient was 397 days, and the longest wait was 1661 days. A further 46.2% of respondents were able to recall cases of patients who in the past 5 years had suffered cardiovascular events with sequelae while awaiting surgery, and 21.2% recalled at least one fatal cardiovascular event in that time. CONCLUSION: Our data revealed an unacceptably long wait for obesity surgery. Notwithstanding the limitations and potential biases of our research, the long wait for surgery in our context inevitably has serious consequences for a potentially significant number of patients.

Surgical treatment of large incisional hernias with intraperitoneal composite mesh: a cohort study.

PURPOSE: Patients with large incisional hernias have significant morbidity and their management is a challenge for the surgical team because of the large abdominal wall involvement. The choice of surgical technique is still controversial. The purpose of this study is to analyze the predictive factors for recurrence after intraperitoneal mesh repair in patients with large incisional hernias. METHODS: A retrospective cohort observational study with a prospectively collected database was performed in the Hospital Clinico San Carlos (Madrid, Spain). All consecutive patients operated on from January 2009 to December 2014 with incisional hernia of 10 or more centimeters in its transverse diameter were included. An intraperitoneal repair with a composite mesh fixed with discontinuous absorbable suture and fibrin sealant was performed. Demographic data, comorbidities, and early and long term outcomes were analyzed. The primary outcome was the presence of recurrence. RESULTS: One hundred and twenty patients were included. Mean age was 63.3 years (SD 12.9) and sex ratio was 1.4:1. Seventy-two patients (60%) were ASA III-IV. Forty-five patients (37.5%) had recurrent ventral hernias. Mean defect size was 14.7 cm (SD 3.21) of width. Overall postoperative morbidity rate was 25%. Median hospital stay was 6 days (IQR 4-8). Recurrence rate was 8.3%, after a median follow-up of 16 months (IQR 10-25). Multivariate analysis showed significant association between ASA III-IV, use of Composix Kugel™ mesh, superficial surgical site infection, and the presence of recurrence. CONCLUSIONS: The recurrence rate after intraperitoneal mesh repair in patients with large incisional hernias might be associated with ASA III-IV, use of Composix Kugel™ mesh, and superficial surgical site infection.

Post-implant Analysis of Epidemiologic and Eating Behavior Data Related to Weight Loss Effectiveness in Obese Patients Treated with Gastric Electrical Stimulation.

OBJECTIVE: To determine possible preoperative predictors for obtaining clinically meaningful weight loss with gastric electrical stimulation (GES) using the "Three-Factor Eating Questionnaire" (TFEQ) as well as epidemiological data. METHODS: Ninety-seven obese participants in a prospective multicenter randomized study conducted in nine European centers were implanted laparoscopically with the abiliti® closed-loop GES system (CLGES). Five clinical variables and three preoperative TFEQ factor scores (F1-cognitive-restraint, F2-disinhibition, and F3-hunger) were analyzed in order to determine predictors of weight loss success defined as excess weight loss (EWL) > 30% and failure defined as EWL < 20% at 12 months post-surgery. RESULTS: The mean 12-month %EWL with CLGES was 35.1 ± 19.7%, with a success rate of 52% and a failure rate of 19%. Significant predictors of success were body mass index (BMI) < 40 kg/m2 and age ≥ 50 years, increasing probability of success by 22 and 29%, respectively. A low F1-cognitive-restraint score was a significant predictor of failure (p = 0.004). The best predictive model for success included F1-cognitive-restraint, F2-disinhibition, BMI < 40, and age ≥ 50 (p = 0.002). CONCLUSION: This retrospective analysis has shown that age, preoperative BMI, and F1-cognitive-restraint and F2-disinhibition scores from a preoperatively administered TFEQ are predictive of weight loss outcomes with CLGES and may be used for patient selection. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01448785.

Aplicación de la Sonificación de Señales Cerebrales en Clasificación Automática / Applying Brain Signals Sonification for Automatic Classification

En años recientes la sonificación de electroencefalogramas (EEG) ha sido utilizada como una alternativa para analizar señales cerebrales al convertir el EEG en audio. En este trabajo se aplica la sonificación a señales de EEG durante el habla imaginada o habla no pronunciada, con el objetivo de mejorar la clasificación automática de 5 palabras del idioma español. Para comprobarlo, se procesó la señal cerebral de 27 sujetos sanos. Estas señales fueron sonificadas para después extraer características con dos métodos diferentes: la transformada Wavelet discreta (DWT); y los coeficientes cepstrales en la escala de Mel (MFCC). Éste último comúnmente utilizado en tareas de reconocimiento de voz. Para clasificar las señales se aplicaron tres algoritmos distintos de clasificación Naive Bayes (NB), Máquina de vectores de soporte (SVM) y Random Forest (RF). Se obtuvieron resultados usando los 4 canales más cercanos a las áreas de lenguaje de Broca y Wernicke, así como también los 14 canales del dispositivo EEG utilizado. Los porcentajes de exactitud promedio para los 27 sujetos en los dos conjuntos de 4 y 14 canales usando sonificación de EEG fueron de 55.83% y 64.14% respectivamente, con lo que se logró mejorar ligeramente los porcentajes de clasificación de las palabras imaginadas respecto a no utilizar sonificación.

In recent years sonification of electroencephalograms (EEG) has been used as an alternative to analyze brain signals after converting EEG to audio. In this paper we applied the sonification to EEG signals during the imagined speech or unspoken speech, with the aim of improving the automatic classification of 5 words of Spanish. To check this, the brain signals of 27 healthy subjects were processed. These sonificated signals were processed to extract features with two different methods: discrete wavelet transform (DWT); and the Mel-frequencies cepstral coefficients (MFCC). The latter commonly used in speech recognition tasks. To classify the signals three different classification algorithms Naive Bayes (NB), Support Vector Machine (SVM) and Random Forest (RF) were applied. Results were obtained using the 4 channels closest to the language areas of Broca and Wernicke, as well as the 14 channels of the EEG device used. The percentages of average accuracy for the 27 subjects in the two sets of 4 and 14 channels using EEG sonification were 55.83% and 64.14% respectively, which are improvements in the classification rates of the imagined words compared with a scheme without sonification.

Evaluation of Water Sanitation Health Education Programme: Working with the Knowledge of the Basic Sanitation Services in a Developing Community in Rural Haiti after the 2010 Earthquake.

OBJECTIVE: The aim of this study is to measure the knowledge regarding the new sanitation water system being implemented in Dessources, a rural community in the municipality of Croix-des-Bouquets in Haiti after a two-year intervention programme. DESIGN AND METHODS: A cross-sectional epidemiologic design was used to measure the knowledge of the people in the community using a semi-structured questionnaire. Data collection followed a face-to-face interview process in all houses of the community. The instrument content validity was performed by a panel of experts followed by Cronbach's alpha test to establish the reliability of knowledge scale. In addition, association measures were done using Stata 11.0 statistical package. RESULTS: Content validity test were performed with minimum changes and an alpha of 0.74 was obtained for the scale. Response rate was 65.57% (41/60 houses); non-participants were only those who did not meet the inclusion criteria. Most of the participants (77.5%) were 21-49 years old and 85% had been living in the community for more than 20 years. Bivariate analysis showed that the people of Dessources had adequate knowledge. Significant differences, however, were found among the zones that are not in use of the new sanitary systems and among families with more than seven members per house. CONCLUSIONS: Differences found can be explained based on the Rogers theoretical diffusion of innovation model. The evaluation shows that people of Dessources in Haiti have a high knowledge regarding the new water sanitation system and provided evidence of an adequate health education programme intervention.

Análisis de señales electroencefalográficas para la clasificación de habla imaginada / Electroencephalographic Signals Analysis for Imagined Speech Classification

El presente trabajo tiene como objetivo interpretar las señales de EEG registradas durante la pronunciación imaginada de palabras de un vocabulario reducido, sin emitir sonidos ni articular movimientos (habla imaginada o no pronunciada) con la intención de controlar un dispositivo. Específicamente, el vocabulario permitiría controlar el cursor de la computadora, y consta de las palabras del lenguaje español: "arriba", "abajo", "izquierda", "derecha", y "seleccionar". Para ello, se registraron las señales de EEG de 27 individuos utilizando un protocolo básico para saber a priori en qué segmentos de la señal la persona imagina la pronunciación de la palabra indicada. Posteriormente, se utiliza la transformada wavelet discreta (DWT) para extraer características de los segmentos que son usados para calcular la energía relativa wavelet (RWE) en cada una de los niveles en los que la señal es descompuesta, y se selecciona un subconjunto de valores RWE provenientes de los rangos de frecuencia menores a 32 Hz. Enseguida, éstas se concatenan en dos configuraciones distintas: 14 canales (completa) y 4 canales (los más cercanos a las áreas de Broca y Wernicke). Para ambas configuraciones se entrenan tres clasificadores: Naive Bayes (NB), Random Forest (RF) y Máquina de vectores de soporte (SVM). Los mejores porcentajes de exactitud se obtuvieron con RF cuyos promedios fueron 60.11% y 47.93% usando las configuraciones de 14 canales y 4 canales, respectivamente. A pesar de que los resultados aún son preliminares, éstos están arriba del 20%, es decir, arriba del azar para cinco clases. Con lo que se puede conjeturar que las señales de EEG podrían contener información que hace posible la clasificación de las pronunciaciones imaginadas de las palabras del vocabulario reducido.

This work aims to interpret the EEG signals associated with actions to imagine the pronunciation of words that belong to a reduced vocabulary without moving the articulatory muscles and without uttering any audible sound (imagined or unspoken speech). Specifically, the vocabulary reflects movements to control the cursor on the computer, and consists of the Spanish language words: "arriba", "abajo", "izquierda", "derecha", and "seleccionar". To do this, we have recorded EEG signals from 27 subjects using a basic protocol to know a priori in what segments of the signal a subject imagines the pronunciation of the indicated word. Subsequently, discrete wavelet transform (DWT) is used to extract features from the segments. These are used to compute relative wavelet energy (RWE) in each of the levels in that EEG signal is decomposed and, it is selected a RWE values subset with the frequencies smaller than 32 Hz. Then, these are concatenated in two different configurations: 14 channels (full) and 4 channels (the channels nearest to the brain areas of Wernicke and Broca). The following three classifiers were trained using both configurations: Naive Bayes (NB), Random Forest (RF) and support vector machines (SVM). The best accuracies were obtained by RF whose averages were 60.11% and 47.93% using both configurations, respectively. Even though, the results are still preliminary, these are above 20%, this means they are more accurate than chance for five classes. Based on them, we can conjecture that the EEG signals could contain information needed for the classification of the imagined pronunciations of the words belonging to a reduced vocabulary.

Morgagni-Larrey parasternal diaphragmatic hernia in the adult.

With a prevalence of 0.3-0.5/1000 births, congenital diaphragmatic hernia (CDH) remains a serious, poorly understood abnormality with a high mortality rate that cannot always be effectively managed. Its reported frequency in Spain is 0.69%00 with a yearly decreasing trend of 0.10%00 during the period 1980-2006. Up to 5% of cases are incidentally identified in adults undergoing studies for other reasons.We report the case of a 74-year-old woman with vomiting for three months due to parasternal diaphragmatic hernia of Morgagni-Larrey (retrochondrosternal, retrocostoxyphoid, retrosternal, subcostal, substernal or subcostosternal hernia), which allowed us to report an update on this condition in the adult, and on thoracoabdominal diaphragm morphogenesis. It is in the embryology of the diaphragm where an explanation may be found for some morphological changes and clinical manifestations, even though a number of uncertainties remain. We also analyze the extent of controversy persisting on some aspects of surgical treatment (access routes, mesh use, hernial sac reduction). Overall, minimally invasive techniques predominate. We consider laparoscopy the approach of choice for adult patients with parasternal hernia eligible for surgery.

Hernia diafragmática paraesternal de Morgagni-Larrey en adulto / Morgagni-Larrey parasternal diaphragmatic hernia in the adult

Con una prevalencia de 0,3-0,5/1.000 nacimientos, la hernia diafragmática congénita (HDC) sigue siendo una anomalía grave, no bien entendida, alta mortalidad y tratamiento no siempre efectivo. En España se ha informado de una frecuencia del 0,69%oo con una tendencia decreciente en el periodo 1980-2006 del 0,10%oo por año. No obstante, hasta un 5% se diagnostican en adultos durante la realización de un reconocimiento por otra causa. Presentamos un cuadro de vómitos de tres meses de evolución en una mujer de 74 años por hernia diafragmática paraesternal de Morgagni-Larrey (retrocondroesternal, retrocostoxifoidea, retroesternal, subcostal, subesternal o subcostoesternal), que nos ha permitido realizar una actualización de esta patología en adultos y de la morfogénesis del diafragma toracoabdominal. Es en la embriología del diafragma donde encontramos explicación de algunas de sus alteraciones morfológicas y características clínicas, si bien persisten aspectos confusos de la misma. También analizamos el grado de controversia que persiste en algunos aspectos de su tratamiento quirúrgico (vías de acceso, uso o no de mallas y reducción o no del saco herniario). Por lo general priman las técnicas mínimamente invasivas. Consideramos el abordaje laparoscópico como de elección en pacientes adultos con hernia paraesternal candidatos a la cirugía(AU)

With a prevalence of 0.3-0.5/1000 births, congenital diaphragmatic hernia (CDH) remains a serious, poorly understood abnormality with a high mortality rate that cannot always be effectively managed. Its reported frequency in Spain is 0.69%oo with a yearly decreasing trend of 0.10%oo during the period 1980-2006. Up to 5% of cases are incidentally identified in adults undergoing studies for other reasons. We report the case of a 74-year-old woman with vomiting for three months due to parasternal diaphragmatic hernia of Morgagni-Larrey (retrochondrosternal, retrocostoxyphoid, retrosternal, subcostal, substernal or subcostosternal hernia), which allowed us to report an update on this condition in the adult, and on thoracoabdominal diaphragm morphogenesis. It is in the embryology of the diaphragm where an explanation may be found for some morphological changes and clinical manifestations, even though a number of uncertainties remain. We also analyze the extent of controversy persisting on some aspects of surgical treatment (access routes, mesh use, hernial sac reduction). Overall, minimally invasive techniques predominate. We consider laparoscopy the approach of choice for adult patients with parasternal hernia eligible for surgery(AU)

Recidiva local tras cirugía del cáncer de pulmón / Local recurrence after lung cancer lung

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Tratamiento quirúrgico de los tumores neuroendocrinos gastroenteropancreáticos / Surgical treatment of gastroenteropancreatic neuroendocrine tumors

La cirugía es el pilar sobre el que descansa el tratamiento de los tumores neuroendocrinos gastroenteropancreáticos. Son tumores que, en general, presentan un buen pronóstico y que muchas veces el único problema al que dan lugar son los síntomas derivados de su secreción endocrina, que se pueden tratar médicamente. Estos hechos han de considerarse siempre que se afronte un tratamiento quirúrgico, que puede ser de agresividad desproporcionada para tan benigna evolución; pero no hay que olvidar que, si existe posibilidad de curación, ésta pasa invariablemente por la exéresis del tumor. No es contraindicación para la resección la presencia de enfermedad a distancia, ya que, por una parte, la cirugía citorreductora tiene un valor indudable y, por otra, existe la posibilidad de resección de las metástasis sin renunciar a la curación, y al menos con la intención de prolongar la supervivencia sin síntomas. El trasplante hepático es controvertido, ya que aunque puede incrementar la supervivencia, la escasez de órganos y la carcinogénesis secundaria a la inmunosupresión cuestionan su utilidad. Recientemente se han diseñado otros tipos de ablación tumoral apoyados por el avance de las técnicas de radiodiagnóstico, que consiguen igualmente buenos resultados para el tratamiento de este tipo peculiar de neoplasias (AU)

Surgery is the cornerstone of the treatment of gastroenteropancreatic tumors. These neoplasms usually have a good prognosis. Endocrine symptoms are often the only problem noticed by the patient and these can be treated pharmacologically. Surgical indication must be considered carefully, as this type of therapy may be too aggressive for benign tumors; on the other hand, the only chance for cure is tumoral resection. Surgery is not contraindicated in cases of distant metastases, as both cytoreductive surgery and metastases resection are associated with an increase in symptom-free survival and, in the latter, to overall survival and sometimes curation. Liver transplantation is controversial; although it can increase survival, its usefulness is limited by the shortage of donors and by carcinogenesis secondary to immunosuppression. Recently, new ablative techniques have been introduced, such as radiofrequency ablation or cryotherapy, both of which achieve good results mainly in the treatment of metastatic disease (AU)

Demora en el tratamiento quirúrgico del cáncer de pulmón / Delay in the surgical treatment of lung cancer

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Recurrence pattern of esophageal cancer after esophagectomy with two-field lymphadenectomy.

AIM: To analyze the pattern of recurrence of esophageal carcinoma after a curative-intention surgical resection. PATIENTS: Ninety-two patients with non-metastatic esophageal carcinoma were included. Ninety percent of patients were male, and the mean age of this series was 61 years. The most frequent histologic subtype was squamous cell carcinoma. Fifty percent of tumors were at or above the tracheal bifurcation. All patients were submitted for transthoracic subtotal esophagectomy plus two-field radical lymphadenectomy, leaving no apparent residual disease. No adjuvant therapy was applied to any patient. RESULTS: Follow-up was complete for 76 out of 80 patients surviving the operation. Thirty-four tumoral recurrences were detected for a disease-free survival af 39% at 9 years after surgery. All recurrences were detected during the first two years after treatment. Tumoral relapse was related to the presence of T3 or T4 tumors, with positive lymph nodes, squamous cell carcinoma subtype and supracarinal location. Nine percent of patients had a distant relapse, 15% had a locorregional relapse and 12% a combination of both. Distant relapse presented significantly earlier. There was no statistical association between type of recurrence and clinico-pathological or surgical features. CONCLUSIONS: After radical surgery for carcinoma of the esophagus, half of the patients relapse in the following two years. Distant metastases happen to appear earlier in the follow-up, but the most frequent recurrence is the locorregional one.

Penetrating chest gunshot wounds: conservative treatment.

Gunshot wounds, and in particular chest gunshot wounds, are becoming a growing problem in daily practice at many hospitals. Many authors propose a conservative attitude in certain cases. We present a patient with a chest gunshot wound successfully solved under conservative means and videothoracoscopic removal of the bullet.