Aplicación de un gestor de tareas colaborativo (Trello) para la tutorización de Trabajos de Fin de Grado y Trabajos de Fin de Máster en la Facultad de Ciencias

Póster presentado en: VIII Jornadas de Innovación Docente de la UBU, Burgos, 5 de abril de 2016, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

Determination of dichlobenil and its major metabolite (BAM) in onions by PTV–GC–MS using PARAFAC2 and experimental design methodology

The optimization of a GC–MS analytical procedure which includes derivatization, Quick Easy Cheap Effective Rugged and Safe (QuEChERS) and programmed temperature vaporization (PTV) using design of experiments is performed to determine 2,6-dichlorobenzonitrile (dichlobenil) and 2,6-dichlorobenzamide (BAM) in onions, using 3,5-dichlorobenzonitrile and 2,4-dichlorobenzamide as internal standards. The use of a central composite design and two D-optimal designs, together with the desirability function, makes it possible to significantly reduce the economic, time and environmental cost of the study. The usefulness of PARAFAC2 for solving problems as the interference of unexpected derivatization artifacts unavoidably linked to some derivatization agents, or the presence of coeluents from the complex matrix, which share m/z ratios with the target compounds, is shown. The limits of decision (CCα) of the optimized procedure, 5.00 μg kg− 1 for dichlobenil and 1.55 μg kg− 1 for BAM (α = 0.05), are below the maximum residue limit (MRL) established by the EU for dichlobenil (20 μg kg− 1) in this commodity.Ministerio de Economía y Competitividad (CTQ2011-26022) and Junta de Castilla y León (BU108A11-2

Detection of cold chain breaks using partial least squares-class modelling based on biogenic amine profiles in tuna

The maintenance of the cold chain is essential to ensure foodstuff conformity and safety. However, gaps in the cold chain may be expected so designing analytical methods capable to detect cold chain breaks is a worthwhile issue. In this paper, the possibility of using the amount of nine biogenic amines (BAs) determined in Thunnus albacares by HPLC-FLD for detecting cold chain breaks is approached. Tuna is stored at 3 different temperature conditions for 8 storage periods. The evolution of the content of BAs is analyzed through parallel factor analysis (PARAFAC), in such a way that storage temperature, BAs and storage time profiles are estimated. PARAFAC has made it possible to observe two spoilage routes with different relative evolution of BAs. In addition, it has enabled to estimate the storage time, by considering the three storage temperatures, with errors of 0.5 and 1.0 days in fitting and in prediction, respectively. Furthermore, a class-modelling technique based on partial least squares is sequentially applied to decide, from the amount of BAs, if there has been a cold chain break. Firstly, samples stored at 25 °C are statistically discriminated from those kept at 4 °C and −18 °C; next, frozen samples are distinguished from those refrigerated. In the first case, the probabilities of false non-compliance and false compliance are almost zero, whereas in the second one, both probabilities are 10%. Globally, the results of this work have pointed out the feasibility of using the amount of BAs together with PLS-CM to decide if the cold chain has been maintained or not.Agencia Estatal de Investigación of Spanish Ministerio de Economía, Industria y Competitividad, Gobierno de España [project CTQ2017-88894-R] and Consejería de Educación de la Junta de Castilla y León [project BU012P17] both co-financed with European Regional Development Fun

A new multi-factor multi-objective strategy based on a factorial presence-absence design to determine polymer additive residues by means of head space-solid phase microextraction-gas chromatography-mass spectrometry

A new multi-factor multi-objective strategy to approach the joint assessment of the effect of six experimental factors in the determination by head space-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) of eight different additives commonly used in the plastic packaging manufacturing is proposed in this work. Five HS-SPME experimental factors, both qualitative and quantitative, are explored: the type of fiber, addition of salt, extraction and desorption time, and extraction temperature. The effect of these factors is studied through a factorial presence-absence model, that include interactions, using a D-optimal design. As a result, the number of experiments is reduced from 128, full factorial design, to 14. The effect of carrying out the measurements in different experimental sessions is considered by including a blocking factor. The response for each compound is estimated in the experimental domain and then the best experimental conditions are chosen by using Pareto front. Parallel coordinates are employed to show the conflicting conditions intrinsic to a multiobjective analysis when compounds of different nature are extracted by HS-SPME. Parallel factor analysis 2 (PARAFAC2) decomposition is used because it makes the determination of target compounds in the presence of unknown interferents possible, which enables the unequivocal identification of target compounds according to official regulations. The developed method is applied to determine 2,6-di-tert-butyl-4-methyl-phenol (BHT), benzophenone (BP), bis(2-ethylhexyl) adipate (DEHA), diethyl phthalate (DEP), diisobutyl phthalate (DiBP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP) and bis(2-ethylhexyl) phthalate (DEHP). The level of these compounds found in nine types of bottled natural still and sparkling mineral waters is very low, so the compounds were not present in quantities that may be injurious to human health.The authors thank the financial support provided by Consejería de la Junta de Castilla y Leon ´ (JCyL) through project BU052P20 co-financed with European FEDER funds. Lucía Valverde-Som thanks JCyL for her postdoctoral contract through this project

Determination of polymer additive residues that migrate from coffee capsules by means of stir bar sorptive extraction-gas chromatography-mass spectrometry and PARAFAC decomposition

This paper reports on the difficulties encountered when developing an analytical method for ultra-trace determination, in a complex matrix, of plastic additive residues which are ubiquitous in the laboratory. The simultaneous qualitative and quantitative determination of an antioxidant (2,6-di-tert-butyl-4-methyl-phenol, BHT), an UV stabilizer (benzophenone, BP), and a plasticizer (diisobutyl phthalate, DiBP), released from plastic capsules is carried out in coffee by means of GC–MS and parallel factor analysis decomposition. Stir bar sorptive extraction is used to extract and concentrate the analytes. Coffee samples are prepared with Milli-Q water, which contains residues of the target compounds, which can be significant for ultra-trace analysis and should be subtracted. In addition, matrix effect exits in coffee, so standard addition method is used. The residue concentrations released from the coffee capsules into the solid coffee are around 3, 1, and 12 μg kg−1 of BHT, BP and DiBP, respectively.Spanish MINECO (AEI/FEDER, UE) through project CTQ2017-88894-R and by Consejería de la Junta de Castilla y León through project BU052P20 (both co-financed with European FEDER funds). L. Valverde-Som thanks JCyL for her postdoctoral contract through BU052P20 project

A new multiresponse optimization approach in combination with a D-Optimal experimental design for the determination of biogenic amines in fish by HPLC-FLD

A new strategy to approach multiresponse optimization in conjunction to a D-optimal design for simultaneously optimizing a large number of experimental factors is proposed. The procedure is applied to the determination of biogenic amines (histamine, putrescine, cadaverine, tyramine, tryptamine, 2- phenylethylamine, spermine and spermidine) in swordfish by HPLC-FLD after extraction with an acid and subsequent derivatization with dansyl chloride. Firstly, the extraction from a solid matrix and the derivatization of the extract are optimized. Ten experimental factors involved in both stages are studied, seven of them at two levels and the remaining at three levels; the use of a D-optimal design leads to optimize the ten experimental variables, significantly reducing by a factor of 67 the experimental effort needed but guaranteeing the quality of the estimates. A model with 19 coefficients, which includes those corresponding to the main effects and two possible interactions, is fitted to the peak area of each amine. Then, the validated models are used to predict the response (peak area) of the 3456 experiments of the complete factorial design. The variability among peak areas ranges from 13.5 for 2-phenylethylamine to 122.5 for spermine, which shows, to a certain extent, the high and different effect of the pretreatment on the responses. Then the percentiles are calculated from the peak areas of each amine. As the experimental conditions are in conflict, the optimal solution for the multiresponse optimization is chosen from among those which have all the responses greater than a certain percentile for all the amines. The developed procedure reaches decision limits down to 2.5 mg L 1 for cadaverine or 497 mg L 1 for histamine in solvent and 0.07 mg kg 1 and 14.81 mg kg 1 in fish (probability of false positive equal to 0.05), respectively.MINECO (CTQ2014-53157-R) and FEDER fund

Partial least squares model inversion in the chromatographic determination of triazines in water

Inside the framework of Analytical Quality by Design, a model-based approach has been developed and used to identify operating conditions (control method parameters) related to the composition and flow rate of the mobile phase for a liquid chromatographic determination with preset quality characteristics. The approach starts by defining these desired characteristics of the intended chromatogram (proper resolution for consecutive peaks and short time of analysis) and then looking for the needed control method parameters via inversion of a Partial Least Squares (PLS) prediction model. The procedure has been applied to the determination of eight triazines (simazine, simetryn, atrazine, ametryn, propazine, terbuthylazine, prometryn and terbutryn) in surface waters by means of SPE-HPLC-DAD. These triazines either are forbidden or have a maximum allowable limit due to their potential toxicity. The experimental verification of the selected parameters showed that the experimental results were significantly equal to those predicted. Besides, the validation of the developed method allowed concluding that accuracy was fulfilled for the eight triazines and there was not bias. With a probability of false positive equal to 0.05, CCβ was less than 3 µg L−1 for every triazine, except for simazine and terbutryn, which was less than 6 µg L−1 being the probability of false negative less than 10-6. No triazine was found, above their maximum allowable concentration, in any of the samples of surface water picked at fifteen different locations, mostly from streams and the Arlanzón river, near Burgos (Spain).Spanish MINECO (AEI/FEDER, UE) through project CTQ2017-88894-R, and Consejería de Educación de la Junta de Castilla y León (BU052P20) both co-financed with European Regional Development Fund

La interdisciplinariedad y el itinerario curricular elegido por el estudiante, ejes fundamentales para desarrollar competencias curriculares en Química

Póster presentado en: V Jornadas de Innovación Docente de la UBU, Burgos, 21-22 de octubre de 2010, organizadas por el Instituto de Formación e Innovación Educativa-IFIE de la Universidad de Burgo

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología