Ocular toxicity after inadvertent overdose of intracameral cefuroxime during cataract surgery.

PURPOSE: To describe intracameral toxic effects of cefuroxime at a higher dose than recommended in cataract surgery. METHODS: Retrospective study of 8 eyes of 8 patients who inadvertently received 12.5 mg/0.1 ml of intracameral cefuroxime due to a dilution error, at the end of the cataract surgery. All patients underwent a strict ophthalmology follow-up for 6 months. RESULTS: All patients presented with a marked anterior segment inflammation with corneal oedema that resolved completely in all cases (between 5 days and 3 months). At 6 months of follow-up a statistically significant difference was found in the corneal endothelial cell density when compared with the fellow eye (P = .038), being <1000 cells/mm2 in 3 cases. Three patients (37.5%) showed early macular oedema, with subfoveal ellipsoid layer disruption in one case as a permanent sequel. One patient developed an optic neuropathy with associated afferent pupillary defect. CONCLUSIONS: Although 1 mg/0.1 ml of intracameral cefuroxime has been shown to reduce the incidence of endophthalmitis, its overdose can have potentially toxic eye effects in both anterior and posterior segments.

Toxicidad ocular tras sobredosificación accidental de cefuroxima intracameral en cirugía de catarata / Ocular toxicity after inadvertent overdose of intracameral cefuroxime during cataract surgery

Objetivo Describir los efectos de la inyección de cefuroxima intracameral a una dosis más alta de la recomendada en cirugía de catarata. Métodos Estudio retrospectivo de 8 ojos de 8 pacientes operados de catarata en un mismo día que recibieron 12,5mg/0,1ml de cefuroxima intracameral de forma inadvertida al finalizar la cirugía, por un error en la dilución. A todos los pacientes se les realizó un seguimiento oftalmológico estrecho durante 6 meses. Resultado Todos los pacientes presentaron una inflamación marcada del segmento anterior con edema corneal que se resolvió en todos los casos (entre 5 días y 3 meses). A los 6 meses de seguimiento se constató una diferencia significativa en el recuento endotelial corneal de dichos ojos al compararlo con el ojo contralateral (p=0,038), siendo<1000cels/mm2 en 3 casos. Tres pacientes (37,5%) presentaron un edema macular precoz, dejando como secuela permanente la disrupción de la capa elipsoidal a nivel subfoveal en uno de los casos. Uno de los pacientes desarrolló una neuropatía óptica con defecto pupilar aferente asociado. Conclusiones Aunque la inyección de cefuroxima en cámara anterior a dosis de 1mg/0,1ml ha demostrado disminuir la incidencia de endoftalmitis, su sobredosificación puede tener efectos oculares potencialmente perjudiciales tanto en el segmento anterior como en el posterior (AU)

Purpose To describe intracameral toxic effects of cefuroxime at a higher dose than recommended in cataract surgery. Methods Retrospective study of 8 eyes of 8 patients who inadvertently received 12.5mg/0.1ml of intracameral cefuroxime due to a dilution error, at the end of the cataract surgery. All patients underwent a strict ophthalmology follow-up for 6 months. Results All patients presented with a marked anterior segment inflammation with corneal oedema that resolved completely in all cases (between 5 days and 3 months). At 6 months of follow-up a statistically significant difference was found in the corneal endothelial cell density when compared with the fellow eye (P=.038), being<1000 cells/mm2 in 3 cases. Three patients (37.5%) showed early macular oedema, with subfoveal ellipsoid layer disruption in one case as a permanent sequel. One patient developed an optic neuropathy with associated afferent pupillary defect. Conclusions Although 1mg/0.1ml of intracameral cefuroxime has been shown to reduce the incidence of endophthalmitis, its overdose can have potentially toxic eye effects in both anterior and posterior segments (AU)

Ocular toxicity after inadvertent overdose of intracameral cefuroxime during cataract surgery. / Toxicidad ocular tras sobredosificación accidental de cefuroxima intracameral en cirugía de catarata.

PURPOSE: To describe intracameral toxic effects of cefuroxime at a higher dose than recommended in cataract surgery. METHODS: Retrospective study of 8 eyes of 8 patients who inadvertently received 12.5mg/0.1ml of intracameral cefuroxime due to a dilution error, at the end of the cataract surgery. All patients underwent a strict ophthalmology follow-up for 6 months. RESULTS: All patients presented with a marked anterior segment inflammation with corneal oedema that resolved completely in all cases (between 5 days and 3 months). At 6 months of follow-up a statistically significant difference was found in the corneal endothelial cell density when compared with the fellow eye (P=.038), being<1000 cells/mm2 in 3 cases. Three patients (37.5%) showed early macular oedema, with subfoveal ellipsoid layer disruption in one case as a permanent sequel. One patient developed an optic neuropathy with associated afferent pupillary defect. CONCLUSIONS: Although 1mg/0.1ml of intracameral cefuroxime has been shown to reduce the incidence of endophthalmitis, its overdose can have potentially toxic eye effects in both anterior and posterior segments.

Current practice of rapid sequence induction in adults: A national survey among anesthesiologists in Spain. / Práctica actual de la inducción de secuencia rápida en adultos: una encuesta nacional entre anestesiólogos en España.

BACKGROUND: Rapid sequence induction (RSI) in adults has undergone changes in recent years due to pharmacological and technological advances. The objective of this survey was to evaluate current practice among Spanish anesthesiologists. METHODS: A 31-item questionnaire regarding RSI practice was sent to anesthesiologists working in Spanish public hospitals. Differences in responses according to the type of hospital or experience of the respondent were compared for all data using the chi-square and Fisher's exact test. RESULTS: Approximately 15.89% of Spanish anesthesiologists participated in the survey (1002 questionnaires). The results show considerable heterogeneity in most aspects of RSI. Less than 20% of respondents administer sodium citrate. Sixty-four percent place a nasogastric tube in patients with intestinal obstruction. Gastric residue is assessed by ultrasound in 6% of cases. Only 25% of respondents measure ETO2 to check the effectiveness of preoxygenation, and 22% use nasal oxygen insufflation with nasal prongs or THRIVE. Sixty two percent of respondents apply cricoid pressure, but only 50% release the pressure when encountering intubation difficulty. Up to 40% of respondents reported cases of aspiration despite applying cricoid pressure. Propofol was the most commonly used hypnotic (97.6%), but there was no clear preference in the choice of neuromuscular relaxant (suxamethonium versus rocuronium ratio of approximately 1:1). Only 44% of respondents calculated the dose of sugammadex that would be required for emergency reversal of rocuronium. CONCLUSIONS: The survey showed significant variation in RSI practice, similar to that of other countries. Quality prospective studies are needed to standardize clinical practice.

Las gotas de silicona tras inyecciones intravítreas: un efecto adverso incómodo en nuestras consultas / Silicone oil droplets after intravitreal injections: An uncomfortable adverse effect in our consultations

No disponible

Do Season and Environment Have a Role in the Incidence of Anterior Uveitis Attacks?

PURPOSE: To investigate the seasonal influence on the incidence of uveitis attacks. METHODS: An ecological study was designed including 731 uveitis attacks in 594 patients diagnosed at the eye emergency of a hospital in Madrid between 2014 and 2017. The incidence of uveitis attacks, B27+, and presumed herpetic attacks were calculated, and their correlations with seasonal and environmental variables in the same timeframe were analyzed. The analyzed variables were precipitation, barometric pressure, temperature, humidity, wind speed, global solar radiation, ultraviolet radiation, air pollution components (particulate matter and polluting gases), and the incidence of influenza. RESULTS: The incidence of attacks was significantly higher in the winter than in the autumn (p = .025). It showed a significant correlation to the number of rainy days per month (r = 0.612;p = .04), and the average wind speed (r = 0.469;p = .02) after Bonferroni correction. CONCLUSION: Uveitis episodes happened more frequently under rainy and windy conditions. Most factors were not significantly correlated to attacks.

Psychosocial and Ergonomic Conditions at Work: Influence on the Probability of a Workplace Accident.

Today, the economic and social importance of occupational accidents is undeniable worldwide. Hence, research aimed at reducing this type of accident is considered a discipline of great interest for society in general. In this environment, working conditions play a fundamental role in the occurrence of accidents, and from their study, results can be obtained that provide information for decision-making that guarantee optimum conditions for the development of the employees' tasks. Organizing the conditions of work execution is also a task that constitutes an essential aspect for a firm's productivity, therefore, affecting their viability and results. In this work, a model is proposed for the study of different groups of working conditions and their influence on the probability of occupational accidents, in accordance with the data provided by the 7th National Survey of Working Conditions (VII NSWC). The survey sampled 8892 workers active in all sectors of national production and is the last nation-wide survey administered in Spain. Bayesian networks (BNs) are used to generate a network that analyzes working conditions in all areas (27 variables have been included in addition to those corresponding to the sector and accident), and then, more specifically, the relationship that is established between ergonomic factors in the workplace, psychosocial factors of the worker, and the probability of an accident. The results are achieved through the network obtained by highlighting some of the proposed variables. The dependencies generated by the chosen variables are analyzed, and subsequently, the probability of accident for each of the productive sectors is determined. It is concluded that the ergonomic risks associated with physical strains in the workplace, together with the lack of job satisfaction on the employer's behalf, both pose a very significant increase in the probability of being involved in an occupational accident, above the other variables of study.

Acute and chronic optic nerve head biomechanics and intraocular pressure changes in patients receiving multiple intravitreal injections of anti-VEGF.

PURPOSE: To evaluate acute and chronic changes in optic nerve head (ONH) structures and intraocular pressure (IOP) in patients receiving intravitreal injections (IVIs) of anti-VEGF. METHODS: Twenty-nine eyes receiving IVIs for the first time were studied. IOP, retinal nerve fiber layer (RNFL) thickness, and ONH structures were evaluated by Spectralis optical coherence tomography with enhanced depth imaging technology. Structures were measured before and 5 min after each one of the three monthly injections of a loading dose treatment. In 13 eyes (44.8%) with more than six IVIs, another evaluation pre and immediately postinjection was performed after 1 year. RESULTS: A significant acute and transient IOP increase (all p ≤ 0.001), Bruch's membrane opening (BMO) enlargement (p ≤ 0.001), cup widening (p < 0.05) and deepening (p ≤ 0.001), and prelaminar tissue thinning (p ≤ 0.001) were observed 5 min after each injection. Compared with baseline values, a significant BMO expansion (p = 0.001) and RNFL thinning (p < 0.001) were observed in the third month. In eyes with more than six IVIs, similar immediate postinjection changes, including IOP increase (p = 0.001), prelaminar tissue thinning (p = 0.007), and cup deepening (p = 0.012) were observed at 1 year, while BMO expansion was not significant (p = 0.556). Compared with baseline preinjection values, a significant BMO expansion (p = 0.003), prelaminar tissue thinning (p = 0.011), and cup deepening (p = 0.006) in the inferior region of the ONH occurred. No change in IOP was observed at the end of follow-up. CONCLUSIONS: Repeated IVIs could lead to irreversible changes in ONH structures. Large-scale, prospective studies are required to determine the long-term effects of anti-VEGF treatments in ONH tissues.

Data on the working population in Spain related to training, workplace conditions and accident rates.

Obtaining data on worker accident rates is necessary in order to analyze the causes and variables involved in the occurrence of said accidents. The majority of these data, collected after the accident occurs, do not consider the employee׳s working conditions. Here are presented the data on workplace accidents and the conditions of the workers by analyzing the generic data supplied as part of the 7th National Survey of Workplace Conditions (EWCS) in Spain, conducted in 2011. These data will yield the variables needed to determine if the information on workplace risks provided by the survey respondents has an appreciable effect on the occurrence of occupational accidents in the working population, and will also be used to explore other variables.

Data on the main working conditions with influence on the development of hearing loss amongst the occupational population in Spain.

Obtaining reliable and objective data on certain working conditions is necessary to analyse the causes and variables that can influence the development of hearing loss amongst the working population. Objective occupational data have been collected from a heterogeneous sample of 1418 workers in Spain, see "How activity type, time on the job and noise level on the job affect the hearing of the working population. Using Bayesian networks to predict the development of hipoacusia" (Barrero et al., 2018) [1]. Among the main factors analysed are the noise levels to which these workers are exposed, measured at their respective workstations, and the assessment of their hearing status, evaluated by audiometric medical tests. These factors provide information to predict the development of hypoacusia.

Sun exposure influences the prognostic power of components of mineral metabolism in patients with coronary artery disease.

BACKGROUND AND AIM: Calcidiol (vitamin D metabolite) plasma levels vary with sun exposure (SE). However, it is not known if SE influences its prognostic ability. We have studied the effect of SE on plasma levels of the components of mineral metabolism (calcidiol, fibroblast growth factor-23 [FGF-23], parathormone [PTH], and phosphate [P]) and on their prognostic value in patients with coronary artery disease (CAD). METHODS AND RESULTS: We studied prospectively 704 patients with stable CAD. Clinical variables and baseline calcidiol, FGF-23, PTH, and P plasma levels were assessed. We divided the population in two subgroups, according to the period of plasma extraction: High SE (HSE) (April-September) and low SE (LSE) (October-March). The outcome was the development of acute ischemic events (acute coronary syndrome, stroke, or transient ischemic attack), heart failure, or death. Mean follow-up was 2.15 ± 0.99 years. Calcidiol and P levels were higher in HSE group. In the whole population, calcidiol (HR = 0.84 for each 5 ng/ml increase, 95% CI = 0.71-0.99; p = 0.038) and FGF-23 (HR = 1.14 for each 100 RU/ml increase, 95% CI = 1.05-1.23; p = 0.009) were predictors of the outcome, along with age, hypertension, body-mass index, peripheral artery disease, and P levels. In the LSE subgroup, calcidiol (HR = 0.75; 95% CI = 0.57-0.99; p = 0.034) and FGF-23 (HR = 1.34; 95% CI = 1.13-1.58; p = 0.003) remained as predictors of the outcome. In the HSE group calcidiol and FGF-23 had not independent prognostic value. CONCLUSIONS: In patients with stable CAD, low calcidiol and high FGF-23 plasma levels predict an adverse prognosis only when the sample is obtained during the months with LSE. SE should be taken into account in the clinical practice.

Anestesia y analgesia epidural en la resección hepática: seguridad y efectividad / Epidural anesthesia and analgesia in liver resection: safety and effectiveness

Objetivos. La analgesia epidural perioperatoria (AE) en la cirugía hepática proporciona una analgesia dinámica óptima. Las alteraciones de la coagulación que se producen en el postoperatorio, añaden un riesgo de complicaciones tras la retirada de los catéteres epidurales. El objetivo de este estudio es evaluar la efectividad y las complicaciones de la AE, así como el retraso en la retirada de los catéteres epidurales asociado a coagulopatía postoperatoria. Métodos. Estudio retrospectivo de los 114 pacientes sometidos a cirugía hepática abierta y AE, de marzo 2012 a febrero 2015. Se analizó la evolución postoperatoria de la intensidad del dolor, de los parámetros de la coagulación y la retirada aplazada de catéteres. Resultados. De los 114 pacientes intervenidos, 73 cumplieron criterios de inclusión. Un 59% de pacientes con hepatectomía mayor (resección ≥ 3 segmentos) y un 15% con cirrosis hepática Child A (11/73). El 96% de los catéteres funcionaron adecuadamente. Un 89% de los pacientes tuvo dolor controlado (escala numérica <3) en reposo y un 8,2% (6 pacientes) presentaron dolor intenso (escala numérica>6) al movimiento. El INR se incrementó en el 2.° día postoperatorio, 1,41 [0,99-2,30], normalizándose en la mayoría de los pacientes al 3.er día postoperatorio, 1,26 [0,90 - 2,20]. El tiempo medio de permanencia del catéter fue de 3,6 (±1,1) días. En 6 pacientes (8%), se aplazó la retirada por alteraciones de la coagulación. Conclusiones. La AE en la hepatectomía resultó una práctica segura, que produjo un óptimo control del dolor postoperatorio. El porcentaje de retiradas aplazadas de catéter por coagulopatía postoperatoria fue bajo, no requiriendo trasfusión de hemoderivados (AU)

Objectives. Perioperative epidural analgesia in liver resection provides optimal dynamic pain relief. Coagulation disorders occurring in the postoperative period can lead to greater risk of complications during epidural catheter removal. The aim of this study is to evaluate the effectiveness and complications of epidural analgesia and delayed epidural catheter removal due to postoperative coagulopathy. Methods. A retrospective study of 114 patients undergoing open liver resection and epidural analgesia, from March 2012 to February 2015. Postoperative course of pain intensity, coagulation parameters and delayed catheter removal was analyzed. Results. Of the 114 operated patients, 73 met the inclusion criteria. 59% of patients received major hepatectomy (resection ≥ 3 segments) and 15% had Child's Class A cirrhosis (11/73). 96% of catheters functioned properly. 89% of patients had controlled pain (numerical rate scale <3) at rest and 8.2% (6 patients) had severe pain (numerical rate scale > 6) with movement. The INR peaked on postoperative day 2, 1.41 [0.99-2.30], and gradually returned to normal values in most patients by postoperative day 4, 1.26 [0.90 - 2.20]. The catheters were left in place 3.6 (± 1.1) days. In 6 patients (8%), catheter removal was postponed due to coagulation disorders. Conclusions. Epidural analgesia for liver resection was a safe practice, which produced optimal control of postoperative pain. The percentage of delayed catheter removal due to postoperative coagulopathy was low, not requiring transfusion of blood products (AU)

Epidural anesthesia and analgesia in liver resection: Safety and effectiveness. / Anestesia y analgesia epidural en la resección hepática: seguridad y efectividad.

OBJECTIVES: Perioperative epidural analgesia in liver resection provides optimal dynamic pain relief. Coagulation disorders occurring in the postoperative period can lead to greater risk of complications during epidural catheter removal. The aim of this study is to evaluate the effectiveness and complications of epidural analgesia and delayed epidural catheter removal due to postoperative coagulopathy. METHODS: A retrospective study of 114 patients undergoing open liver resection and epidural analgesia, from March 2012 to February 2015. Postoperative course of pain intensity, coagulation parameters and delayed catheter removal was analyzed RESULTS: Of the 114 operated patients, 73 met the inclusion criteria. 59% of patients received major hepatectomy (resection ≥ 3 segments) and 15% had Child's Class A cirrhosis (11/73). 96% of catheters functioned properly. 89% of patients had controlled pain (numerical rate scale <3) at rest and 8.2% (6 patients) had severe pain (numerical rate scale > 6) with movement. The INR peaked on postoperative day 2, 1.41 [0.99-2.30], and gradually returned to normal values in most patients by postoperative day 4, 1.26 [0.90 - 2.20]. The catheters were left in place 3.6 (± 1.1) days. In 6 patients (8%), catheter removal was postponed due to coagulation disorders. CONCLUSIONS: Epidural analgesia for liver resection was a safe practice, which produced optimal control of postoperative pain. The percentage of delayed catheter removal due to postoperative coagulopathy was low, not requiring transfusion of blood products.

Gold-palladium core@shell nanoalloys: experiments and simulations.

In this work, we report a facile synthesis route, structural characterization, and full atomistic simulations of gold-palladium nanoalloys. Through aberration corrected-STEM, UV-vis spectroscopy and EDS chemical analysis, we were able to determine that Au(core)-Pd(shell) bimetallic nanoparticles were formed. Using different computational approaches, we were capable of establishing how the size of the core and the thickness of the shell will affect the thermodynamic stability of several core-shell nanoalloys. Finally, grand canonical simulations using different sampling procedures were used to study the growth mechanism of Pd atoms on Au seeds of different shapes.

Análisis del contenido, posicionamiento y calidad de páginas web en español relacionadas con la nutrición y los trastornos de la conducta alimentaria / Contents, positioning and quality analysis in Spanish websites related to nutrition and eating behavior disorders

Introducción: Los trastornos del comportamiento alimentario (TCA) son las patologías psicológicas que más se han incrementado en los últimos años. Uno de los factores que determina la elevada prevalencia de TCA en nuestra sociedad es el gran desconocimiento sobre alimentación. Este desconocimiento puede deberse a la consulta de recursos online sin validez científica. Objetivo y ámbito: El objetivo de este trabajo ha sido analizar la calidad científica y el posicionamiento de los sitios web en español con información sobre nutrición, TCA y obesidad. Material y métodos: Se realizó una búsqueda de páginas web en el navegador Google Chrome con las palabras clave: dieta, anorexia, bulimia, nutrición y obesidad, seleccionándose los 20 primeros resultados de cada búsqueda según los índices de posicionamiento ofrecidos por SEOquake (Page Rank, Alexa Rank y SEMrush Rank). Las variables de análisis fueron: información relacionada con dietas y hábitos alimentarios, información sobre alimentación saludable, información sobre TCA y sus criterios diagnósticos e información de carácter formativo acerca de temas profesionales de salud general. Resultados: Sólo el 50% de las web encontradas cumplían los criterios de inclusión en el estudio. La mayoría no seguían las pautas establecidas por e-Europa sobre calidad. La mediana de Page Rank fue de 2, excepto en aquellas asociadas a instituciones sanitarias de prestigio. Conclusiones: Dada la escasez de webs sanitarias con rigor científico, es imprescindible la revisión de las existentes y la creación de nuevos espacios on-line cuya supervisión sea realizada por profesionales especialistas en salud y nutrición (AU)

Introduction: Eating disorders are serious psychological disorders with an increased incidence in last years. One of the factors that determine the high prevalence of eating disorders in our society is the lack of knowledge about nutrition. One of the reasons of this lack of knowledge could be the presence of online resources without scientific validity. Objective and Scope: The aim of this study was to analyze the scientific quality and positioning of websites in Spanish that have information on nutrition, eating disorders and obesity. Materials and Methods: For this purpose, a web search was conducted in the Google Chrome browser using the key words: diet, anorexia, bulimia, obesity and nutrition, and selecting the first 20 results of each search at the rates offered by SeoQuake positioning (Page Rank, AlexaRank y SEMrush Rank). The variables used for the analysis were: information related to eating habits and diets, information on healthy eating, information about eating disorders and their diagnostics, and formative information about general health topics with professional criteria. Results: Only the 50% of the webpages accomplished the inclusion criteria for this study. Most of them did not follow the guidelines established by e- Europe assessment for quality. The median of the Webpage’s PageRank was2, except those associated with health institutions. Conclusions: Given the scarcity of healthcare websites with scientific rigor is essential to review the existing one and to create new online spaces whose supervision must be carried out by specialists in health and nutrition (AU)

Monolayer protected gold nanoparticles: the effect of the headgroup-Au interaction.

In this work we present an atomistic simulation study analyzing the effect of ligand molecules on the morphology and crystalline structure of monolayer protected gold nanoparticles (NPs). In particular, we focused on Au NPs covered with alkyl thiolates (-SR), which form a strong covalent bond with the Au surface, and alkyl amines (-NH2R), which physisorb onto gold. The atomic interactions between gold and the head groups of ligand molecules were represented by means of a recently developed bond-order potential [Olmos-Asar et al., Phys. Chem. Chem. Phys., 2011, 13, 6500]. We found in the case of strong passivants (i.e. -SR) significant surface damage and/or amorphous-like structures, whereas soft passivants (-NH2R) do not produce almost any distortion in the crystalline structure of the metallic NPs. The enriched coverage degree related to flat surfaces is also discussed. We have also demonstrated that the new semi-empirical potential can reproduce low-coordinated adsorption sites, unlike usual pairwise classical potentials. In general, our simulations provide a direct observation of the structure of ligand protected gold nanoparticles.

[Contents, positioning and quality analysis in Spanish websites related to nutrition and eating behavior disorders]. / Análisis del contenido, posicionamiento y calidad de páginas web en español relacionadas con la nutrición y los trastornos de la conducta alimentaria.

INTRODUCTION: Eating disorders are serious psychological disorders with an increased incidence in last years. One of the factors that determine the high prevalence of eating disorders in our society is the lack of knowledge about nutrition. One of the reasons of this lack of knowledge could be the presence of online resources without scientific validity. OBJECTIVE AND SCOPE: The aim of this study was to analyze the scientific quality and positioning of websites in Spanish that have information on nutrition, eating disorders and obesity. MATERIALS AND METHODS: For this purpose, a web search was conducted in the Google Chrome browser using the key words: diet, anorexia, bulimia, obesity and nutrition, and selecting the first 20 results of each search at the rates offered by SeoQuake positioning (Page Rank, Alexa Rank y SEMrush Rank). The variables used for the analysis were: information related to eating habits and diets, information on healthy eating, information about eating disorders and their diagnostics, and formative information about general health topics with professional criteria. RESULTS: Only the 50% of the webpages accomplished the inclusion criteria for this study. Most of them did not follow the guidelines established by e- Europe assessment for quality. The median of the Webpage's PageRank was 2, except those associated with health institutions. CONCLUSIONS: Given the scarcity of healthcare websites with scientific rigor is essential to review the existing one and to create new online spaces whose supervision must be carried out by specialists in health and nutrition.

Introducción: Los trastornos del comportamiento alimentario (TCA) son las patologías psicológicas que más se han incrementado en los últimos años. Uno de los factores que determina la elevada prevalencia de TCA en nuestra sociedad es el gran desconocimiento sobre alimentación. Este desconocimiento puede deberse a la consulta de recursos online sin validez científica. Objetivo y ámbito: El objetivo de este trabajo ha sido analizar la calidad científica y el posicionamiento de los sitios web en español con información sobre nutrición, TCA y obesidad. Material y métodos: Se realizó una búsqueda de páginas web en el navegador Google Chrome con las palabras clave: dieta, anorexia, bulimia, nutrición y obesidad, seleccionándose los 20 primeros resultados de cada búsqueda según los índices de posicionamiento ofrecidos por SEOquake (Page Rank, Alexa Rank y SEMrush Rank). Las variables de análisis fueron: información relacionada con dietas y hábitos alimentarios, información sobre alimentación saludable, información sobre TCA y sus criterios diagnósticos e información de carácter formativo acerca de temas profesionales de salud general. Resultados: Sólo el 50% de las web encontradas cumplían los criterios de inclusión en el estudio. La mayoría no seguían las pautas establecidas por e-Europa sobre calidad. La mediana de Page Rank fue de 2, excepto en aquellas asociadas a instituciones sanitarias de prestigio. Conclusiones: Dada la escasez de webs sanitarias con rigor científico, es imprescindible la revisión de las existentes y la creación de nuevos espacios on-line cuya supervisión sea realizada por profesionales especialistas en salud y nutrición.

Using Bayesian networks to analyze occupational stress caused by work demands: preventing stress through social support.

Occupational stress is a major health hazard and a serious challenge to the effective operation of any company and represents a major problem for both individuals and organizations. Previous researches have shown that high demands (e.g. workload, emotional) combined with low resources (e.g. support, control, rewards) are associated with adverse health (e.g. psychological, physical) and organizational impacts (e.g. reduced job satisfaction, sickness absence). The objective of the present work is to create a model to analyze how social support reduces the occupational stress caused by work demands. This study used existing Spanish national data on working conditions collected by the Spanish Ministry of Labour and Immigration in 2007, where 11,054 workers were interviewed by questionnaire. A probabilistic model was built using Bayesian networks to explain the relationships between work demands and occupational stress. The model also explains how social support contributes positively to reducing stress levels. The variables studied were intellectually demanding work, overwork, workday, stress, and social support. The results show the importance of social support and of receiving help from supervisors and co-workers in preventing occupational stress. The study provides a new methodology that explains and quantifies the effects of intellectually demanding work, overwork, and workday in occupational stress. Also, the study quantifies the importance of social support to reduce occupational stress.