Dispersive solid phase extraction/ fluorescence analysis of riboflavin using sepiolite as sorbent

The use of a natural clay, sepiolite (Sep), and graphene (G)/Sep mixtures as sorbents for the solid phase extraction in dispersive mode (dSPE) with fluorescence detection of a biologically interesting molecule, riboflavin, is reported. The retention of riboflavin by Sep is quantitative with different volumes of the sample and 10?50?mg of the clay. The desorption process has been performed using aqueous solutions of surfactants of different nature: anionic sodium dodecylsulphate (SDS), cationic hexadecyltrimethylammonium chloride (CTAC) and non-ionic polyoxyethylene-23-lauryl eter (Brij L23). The non-ionic surfactant provides the highest riboflavin recoveries; upon optimization of the process, that takes less than half an hour, an extraction yield of 93% was attained using 40?mM Brij L23. The developed method has been applied to the analysis of beer, soya drink and infant milk samples with excellent accuracy (recoveries of 100%) and very good precision, avoiding the interferences of the matrix components that hinder the direct fluorescence analysis of riboflavin.Ministerio de Economía y Competitivida

Graphene/sepiolite mixtures as dispersive solid-phase extraction sorbents for the anaysis of polycyclic aromatic hydrocarbons in wastewater using surfactant aqueous solutions for desorption

tDifferent graphene/sepiolite (G/Sep) solid mixtures have been prepared and tested as nanometric sor-bents for the analysis of polycyclic aromatic hydrocarbons (PAHs) using dispersive solid phase extraction(dSPE) and aqueous solutions of surfactants as environmentally friendly agents for desorption. Quantifi-cation of the PAHs was carried out by reversed-phase liquid chromatography (RP-HPLC) with fluorescencedetection. The adsorption of four PAHs with increasing number of benzene rings into a G/Sep mixture(2/98, w/w) was investigated. A 100% retention was attained for phenanthrene (Phe), pyrene (Pyr) andbenzo(a)pyrene (BaP), while for naphthalene (Nap) the maximum retention was close to 75%. The G/Sepmixtures can be used to remove the PAHs from wastewater. The desorption step was carried out usingan aqueous surfactant solution: 100 mM non-ionic polyoxiethylen-23-lauryl eter (Brij L23). Consideringthe whole extraction process, the highest PAH recoveries (50, 92, 83 and 76% for Nap, Phe, Pyr and BaP,respectively) were obtained using 100 mM Brij L23. The developed method shows very high sensitivity,robustness and precision, as well as low limits of detection and quantification, and has been successfullyapplied to the analysis of PAHs in wastewater samples.Ministerio de Economía y Competitivida

Impact of recovery correction or subjecting calibrators to sample preparation on measurement uncertainty: PAH determinations in waters

The decision on the fitness of a measurement for its intended use and the interpretation of an analytical result requires the assessment of the measurement uncertainty. Frequently, the determination of analytes in complex matrices involves demanding sample preparations in which analyte losses are observed. These losses should be considered when reporting the results, which can be corrected for low recovery by taking the mean recovery observed in the analysis of reference items (e.g. spiked samples) or, alternatively, by subjecting calibrators to the same pre-treatment performed on the samples. In these cases, neat (NC) or adjusted (AC) calibrators are used, respectively. The way analyte losses are handled impacts on the measurement uncertainty. The top-down evaluation of the measurement uncertainty involves combining precision, trueness and additional uncertainty components. The trueness component is quantified by pooling various analyte recovery determinations. This work assesses and compares the uncertainty of polycyclic aromatic hydrocarbons (PAHs) measurements in water based on HPLC-FD calibrations with NC or AC. The trueness component is estimated by pooling mean recoveries observed from the analysis of different spiked samples to which mean recovery uncertainty and degrees of freedom are used to estimate a weighted mean recovery and respective uncertainty. The performance of measurements based on NC and AC are associated with equivalent uncertainty except when large analyte losses are observed, namely in the determination of Naphtalene. In this case, the processing of AC reduces the expanded relative uncertainty from 9.9% to 3.5%. The evaluated expanded uncertainty ranged from 3.5% to 12% of the measured value.Ministerio de Economía y CompetitividadBanco SantanderFundação para a Ciência e Tecnologí

Treatment variability and its relationships to outcomes among patients with Wernicke's encephalopathy: A multicenter retrospective study

Background: Despite guidelines and recommendations, Wernicke's encephalopathy (WE) treatment lacks evidence, leading to clinical practice variability.Aims: Given the overall lack of information on thiamine use for WE treatment, we analyzed data from a large, well-characterized multicenter sample of patients with WE, examining thiamine dosages; factors associated with the use of different doses, frequencies, and routes; and the influence of differences in thiamine treatment on the outcome.Methods: This retrospective study was conducted with data from 443 patients from 21 centers obtained from a nationwide registry of the Spanish Society of Internal Medicine (from 2000 to 2012). Discharge codes and Caine criteria were applied for WE diagnosis, and treatment-related (thiamine dosage, frequency, and route of administration) demographic, clinical, and outcome variables were analyzed.Results: We found marked variability in WE treatment and a low rate of high-dose intravenous thiamine administration. Seventy-eight patients out of 373 (20.9%) received > 300 mg/day of thiamine as initial dose. Patients fulfilling the Caine criteria or presenting with the classic WE triad more frequently received parenteral treatment. Delayed diagnosis (after 24 h hospitalization), the fulfillment of more than two Caine criteria at diagnosis, mental status alterations, and folic acid deficiency were associated significantly with the lack of complete recovery. Malnutrition, reduced consciousness, folic acid deficiency, and the lack of timely thiamine treatment were risk factors for mortality.Conclusions: Our results clearly show extreme variability in thiamine dosages and routes used in the management of WE. Measures should be implemented to ensure adherence to current guidelines and to correct potential nutritional deficits in patients with alcohol use disorders or other risk factors for WE

Contenidos audiovisuales y plataformas VoD en España: estudios de caso

Este libro editado en formato PDF forma parte de la colección iniciada en el año 2012 a partir de la compilación de los trabajos de investigación más destacados realizados por el estudiantado de la asignatura Estructura del mercado audiovisual, en el grado de Comunicación Audiovisual de la Universidad de Málaga. Aquí se abordan objetos de estudio relacionados con la producción y el consumo de contenidos audiovisuales desde diversas metodologías que analizan los diferentes sectores del audiovisual desde una perspectiva industrial y económica. En una disciplina en la que se estima necesaria una mayor actualización en la investigación académica, los trabajos aquí presentados presentan casos de estudio paradigmáticos del estado de la industria del audiovisual en España. Dichos textos, presentados aquí como capítulos, suponen la introducción en la investigación de estudiantes que combinan su formación académica e investigadora con su formación como profesionales en el área de la Comunicación Audiovisual. Ofrecemos aquí una selección de aquellas investigaciones que destacan por su interés, su capacidad analítica y crítica, su actualidad, su pertinencia y su disciplinada adecuación a una metodología de investigación apropiada dentro de las Ciencias Sociales. En el año 2022, a las puertas de lo que parece una inminente recesión económica, las industrias audiovisuales han recuperado parte del volumen de negocio perdido durante los años de pandemia de Covid-19. Las plataformas OTT han dejado de constituir una novedad y se han integrado y consolidado dentro del mercado, como medio de comercialización de contenidos audiovisuales prioritario en los hogares

Treatment variability and its relationships to outcomes among patients with Wernicke's encephalopathy : A multicenter retrospective study

CatedresBackground: Despite guidelines and recommendations, Wernicke's encephalopathy (WE) treatment lacks evidence, leading to clinical practice variability. Aims: Given the overall lack of information on thiamine use for WE treatment, we analyzed data from a large, well-characterized multicenter sample of patients with WE, examining thiamine dosages; factors associated with the use of different doses, frequencies, and routes; and the influence of differences in thiamine treatment on the outcome. Methods: This retrospective study was conducted with data from 443 patients from 21 centers obtained from a nationwide registry of the Spanish Society of Internal Medicine (from 2000 to 2012). Discharge codes and Caine criteria were applied for WE diagnosis, and treatment-related (thiamine dosage, frequency, and route of administration) demographic, clinical, and outcome variables were analyzed. Results: We found marked variability in WE treatment and a low rate of high-dose intravenous thiamine administration. Seventy-eight patients out of 373 (20.9%) received > 300 mg/day of thiamine as initial dose. Patients fulfilling the Caine criteria or presenting with the classic WE triad more frequently received parenteral treatment. Delayed diagnosis (after 24 h hospitalization), the fulfillment of more than two Caine criteria at diagnosis, mental status alterations, and folic acid deficiency were associated significantly with the lack of complete recovery. Malnutrition, reduced consciousness, folic acid deficiency, and the lack of timely thiamine treatment were risk factors for mortality. Conclusions: Our results clearly show extreme variability in thiamine dosages and routes used in the management of WE. Measures should be implemented to ensure adherence to current guidelines and to correct potential nutritional deficits in patients with alcohol use disorders or other risk factors for WE

Alcoholic Liver Disease Among Patients with Wernicke Encephalopathy : A Multicenter Observational Study

CatedresBackground: data regarding the association between Wernicke encephalopathy (WE) and alcoholic liver disease (ALD) are scarce in spite of alcohol consumption being the main risk factor for WE. Aims: to describe the frequency of ALD in a cohort of patients diagnosed with WE and alcohol use disorders (AUDs) and to compare the characteristics of WE patients with and without ALD. Methods: we conducted an observational study in 21 centers through a nationwide registry of the Spanish Society of Internal Medicine. WE Caine criteria were applied and demographic, clinical, and outcome variables were analyzed. Results: 434 patients were included in the study, of which 372 were men (85.7%), and the mean age was 55 ± 11.8 years. ALD was present in 162 (37.3%) patients and we found a higher percentage of cases with tremor, flapping and hallucinations in the ALD group. A total of 22 patients (5.0%) died during admission (7.4% with ALD vs 3.7% without ALD; P = 0.087). Among the ALD patients, a relationship between mortality and the presence of anemia (Odds ratio [OR]=4.6 Confidence interval [CI]95% 1.1-18.8; P = 0.034), low level of consciousness (OR=4.9 CI95% 1.1-21.2; P = 0.031) and previous diagnosis of cancer (OR=10.3 CI95% 1.8-59.5; P = 0.009) was detected. Complete recovery was achieved by 27 patients with ALD (17.8%) and 71 (27.8%) without ALD (P = 0.030). Conclusion: the association of WE and ALD in patients with AUDs is frequent and potentially linked to differences in clinical presentation and to poorer prognosis, as compared to alcoholic patients with WE without ALD

Alcoholic Liver Disease Among Patients with Wernicke Encephalopathy: A Multicenter Observational Study

Background: data regarding the association between Wernicke encephalopathy (WE) and alcoholic liver disease (ALD) are scarce in spite of alcohol consumption being the main risk factor for WE. Aims: to describe the frequency of ALD in a cohort of patients diagnosed with WE and alcohol use disorders (AUDs) and to compare the characteristics of WE patients with and without ALD. Methods: we conducted an observational study in 21 centers through a nationwide registry of the Spanish Society of Internal Medicine. WE Caine criteria were applied and demographic, clinical, and outcome variables were analyzed. Results: 434 patients were included in the study, of which 372 were men (85.7%), and the mean age was 55 ± 11.8 years. ALD was present in 162 (37.3%) patients and we found a higher percentage of cases with tremor, flapping and hallucinations in the ALD group. A total of 22 patients (5.0%) died during admission (7.4% with ALD vs 3.7% without ALD; P = 0.087). Among the ALD patients, a relationship between mortality and the presence of anemia (Odds ratio [OR]=4.6 Confidence interval [CI]95% 1.1-18.8; P = 0.034), low level of consciousness (OR=4.9 CI95% 1.1-21.2; P = 0.031) and previous diagnosis of cancer (OR=10.3 CI95% 1.8-59.5; P = 0.009) was detected. Complete recovery was achieved by 27 patients with ALD (17.8%) and 71 (27.8%) without ALD (P = 0.030). Conclusion: the association of WE and ALD in patients with AUDs is frequent and potentially linked to differences in clinical presentation and to poorer prognosis, as compared to alcoholic patients with WE without ALD