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Respiration in streams is controlled by the timing, magnitude, and quality of organic matter (OM) inputs from internal primary production and external fluxes. Here, we estimated the contribution of different OM sources to seasonal, annual, and event-driven characteristics of whole-stream ecosystem respiration (ER) using an inverse modeling framework that accounts for possible time-lags between OM inputs and respiration. We modeled site-specific, dynamic OM stocks contributing to ER: autochthonous OM from gross primary production (GPP); allochthonous OM delivered during flow events; and seasonal pulses of leaf litter. OM stored in the sediment and dissolved organic matter (DOM) transported during baseflow were modeled as a stable stock contributing to baseline respiration. We applied this modeling framework to five streams with different catchment size, climate, and canopy cover, where multi-year time series of ER and environmental variables were available. Overall, the model explained between 53% and 74% of observed ER dynamics. Respiration of autochthonous OM tracked seasonal peaks in GPP in spring or summer. Increases in ER were often associated with high-flow events. Respiration associated with litter inputs was larger in smaller streams. Time lags between leaf inputs and respiration were longer than for other OM sources, likely due to lower biological reactivity. Model estimates of source-specific ER and OM stocks compared well with existing measures of OM stocks, inputs, and respiration or decomposition. Our modeling approach has the potential to expand the scale of comparative analyses of OM dynamics within and among freshwater ecosystems. U.S. Department of Energy, Office of Science, Biological and Environmental Research Program; NSF DEB [1442439, 1832012]; USDA NIFA McIntire-Stennis Project [MO-MCNR0008]; MCIN/AEI [PID2020-114024GB-C31] Published version The authors would like to thank two anonymous Reviewers, the Associate Editor, and the Editor-in-Chief for their insightful and constructive comments. This work was initiated at the Heterotrophic Regimes workshop in Ovronnaz, Switzerland. We thank Tom Battin and Amber Ulseth for helping organize the workshop, and workshop participants for useful feedback on early conceptions of this model. Metabolism, temperature, and flow data for Walker Branch were provided by Brian Roberts and Natalie Griffiths and funded by the U.S. Department of Energy, Office of Science, Biological and Environmental Research Program. The authors acknowledge Patrick Mulholland and Brian Roberts for conducting the original Walker Branch study that serves as the foundation for much of our current work characterizing multi-annual stream metabolism dynamics. This project was supported by the Respiration Regimes in River Networks Workshop (NSF DEB #1832012), and the StreamPULSE project (; NSF DEB# 1442439). Daniel von Schiller is a Serra Hunter Fellow and was additionally supported by project Alter-C (PID2020-114024GB-C31) funded by MCIN/AEI/. Alba Argerich was supported by USDA NIFA McIntire-Stennis Project #MO-MCNR0008. This is contribution #1484 from the Institute of Environment at Florida International University.

Aquest treball té la finalitat d’estudiar la dinàmica de la fase vítria de dos compostos, el clotrimazole (CLOT) i la 2-bencilpiridina (2-BP). El CLOT és un fàrmac utilitzat pel tractament de malalties o infeccions ocasionades generalment per fongs mentre que la 2-BP s’utilitza a la indústria com a reactiu i subproducte per a la fabricació d’altres substàncies. Durant aquest estudi s’han realitzat dos tipus de tècniques experimentals, la calorimetria diferencial d’escombrat i l’espectrometria dielèctrica de banda ampla. La primera tècnica correspon a una anàlisi termoanalític per tal de detectar i estudiar els canvis físics que pateix una determinada substància en funció de la temperatura. L’espectrometria dielèctrica utilitzada ha permès estudiar les propietats dielèctriques dels dos compostos mencionats anteriorment, així com la dinàmica de les relaxacions en la fase vítria respecte a un rang de freqüències determinat. Amb aquesta tècnica s’han pres mesures del temps de relaxació (resposta dels dipols de les substàncies davant una excitació externa) de les dues substàncies al reorientar-se en funció del camp elèctric altern aplicat. Estudiar els temps de relaxació en relació amb la temperatura que es produeixen durant la fase vítria, permet obtenir informació sobre la dinàmica interna de les molècules així com les interaccions cooperatives que es produeixen entre elles en orientar-se amb el camp elèctric. Pel CLOT s’han registrat tres tipus relaxacions, una primària i dues secundàries, mentre que pel 2-BP s’ha detectat una primària i una secundària. En aquesta memòria es dóna una interpretació dels resultats obtinguts a partir de dades experimentals sobre els orígens dels diferents pics per tal de comprendre el comportament de les fases amorfes dels compostos mencionats. Este trabajo tiene la finalidad de estudiar la dinámica de la fase vítrea de dos compuestos, el clotrimazol (CLOT) y la 2-bencilpiridina (2-BP). El CLOT es un fármaco utilizado para el tratamiento de enfermedades o infecciones ocasionadas generalmente por hongos, mientras que la 2-BP se utiliza en la industria como reactivo y subproducto para la fabricación de otras sustancias. Durante este estudio se han realizado dos tipos de técnicas experimentales, la calorimetría diferencial de barrido y la espectrometría dieléctrica de banda ancha. La primera técnica corresponde a un análisis termoanalítico a fin de detectar y estudiar los cambios físicos que sufre una determinada sustancia en función de la temperatura. La espectrometría dieléctrica utilizada ha permitido estudiar las propiedades dieléctricas de los dos compuestos mencionados anteriormente, así como la dinámica de las relajaciones en la fase vítrea respecto a un rango de determinadas frecuencias. Con esta técnica se han tomado medidas del tiempo de relajación (respuesta de los dipolos de las sustancias frente a una excitación externa) de las dos sustancias al reorientarse en función del campo eléctrico alterno aplicado. Estudiar los tiempos de relajación con relación a la temperatura que se producen durante la fase vítrea, permite obtener información sobre la dinámica interna de las moléculas, así como las interacciones cooperativas que se producen entre ellas al orientarse con el campo eléctrico. Por el CLOT se han registrado tres tipos de relajaciones, una primaria y dos secundarias, mientras que por el 2-BP se ha detectado una primaria y una secundaria. En esta memoria se da una interpretación de los resultados obtenidos a partir de datos experimentales sobre los orígenes de los distintos picos para comprender el comportamiento de las fases amorfas de los compuestos mencionados. This work aims to study the dynamics of the vitreous phase of two compounds, clotrimazole (CLOT) and 2-benzylpyridine (2-BP). CLOT is a drug used to treat diseases or infections usually caused by fungi while 2-BP is used in industry as a reagent and by-product for the manufacture of other substances. During this study, two types of experimental techniques have been carried out, differential scanning calorimetry and broadband dielectric spectrometry. The first technique corresponds to a thermoanalytical analysis in order to detect and study the physical changes that a certain substance undergoes as a function of temperature. The dielectric spectrometry used has made it possible to study the dielectric properties of the two compounds mentioned above, as well as the dynamics of the relaxations in the glassy phase with respect to a range of determined frequencies. With this technique measurements have been taken of the relaxation time (response of the dipoles of the substances to an external excitation) of the two substances as they reorient themselves according to the applied alternating electric field. Studying the relaxation times in relation to the temperature that occur during the vitreous phase allows to obtain information on the internal dynamics of the molecules as well as the cooperative interactions that occur between them when they orient themselves with the electric field. Three types of relaxations have been recorded by CLOT, one primary and two secondary, while by 2-BP one primary and one secondary have been detected. This report gives an interpretation of the results obtained from experimental data on the origins of the different peaks in order to understand the behavior of the amorphous phases of the compounds mentioned.

The Diels–Alder reaction is a prototypical example of a thermally allowed [4 + 2] cycloaddition with good control over the regio- and stereochemical outcomes. Therefore, Diels–Alder reactions in which adjacent stereocenters are generated at the two ends of the newly formed single bonds imply two different possible stereochemical outcomes. In cases where the dienophile has a single electron-withdrawing substituent, the outcome can often be predicted by applying the known “endo rule”. Furthermore, the use of chiral eutectic solvents in asymmetric synthesis has become a novel tool to maintain sustainability in organic synthesis. In the present work, a set of recyclable and sustainable bio-based deep eutectic solvents (DESs) was designed using hydrogen bond acceptors (HBAs) with a chiral center. These compounds were used in their racemic and enantiomerically enriched forms to prepare DESs with lactic acid (LA), glycerol (Gly), and ethylene glycol, which act as hydrogen bond donors (HBDs) in the corresponding eutectic mixture. These DESs were used as solvents to study the reaction between cyclopentadiene and ethyl acrylate or butyl acrylate in typical [4 + 2] cycloadditions. The best yields and endo-selectivity were achieved using LA as the HBD in the eutectic mixtures. The results and adduct ratios obtained show that these DESs were able to improve both reaction yields and selectivity when compared to those observed in organic solvents or ionic liquids. Moreover, the reaction products (adducts) were easily recovered with diethyl ether from the reaction mixture, where they appeared as an upper layer. The authors are grateful to the DBA center for providing the research facilities and equipment. DBA is a certified agent TECNIO in the category of technology developers from the Government of Catalonia. The authors would like to thank the Catalan Government for the quality accreditation given to the Agricultural Biotechnology and Bioeconomy Unit (2017 SGR 828). This work has been partially funded by the Spanish government grant (PID2019-110735RB-C21-MINECO/ FEDER) and Catalan government grant (2017 SGR 828).

Enantioenriched spirocyclic compounds bearing three contiguous stereocenters and high functionalization were obtained through a formal [3+2] cycloaddition reaction catalyzed by a cooperative system. The spiro compounds were synthesized from 4-arylideneisoxazol-5-ones and isocyanoacetate esters using a bifunctional squaramide/Brønsted base organocatalyst derived from a Cinchona alkaloid and silver oxide as Lewis acid. This method afforded two out of the four possible diastereomers with good yields and high enantiomeric excess for both diastereomers.

[eng] The synthesis of heterocyclic organic compounds allows access to a wide arsenal of compounds with potential pharmacological activity. This Thesis is part of the field of pharmaceutical chemistry, developing new therapeutic strategies through the design, synthesis and pharmacological evaluation of various families of compounds aimed at treating diseases that currently do not have a therapeutic solution. In the first chapter, the steps followed for the development, in its preclinical phase, of a representative compound that was the object of intellectual protection by the Fundació Bosch i Gimpera (UB) are explained. In the second chapter, the synthetic studies resulting from the exploration of the reactivity of different positions of the family of bicyclic α-iminophosphonates are exposed, which have allowed access to new structures that have been subjected to pharmacological evaluation. Specifically, it has been possible to access a family of compounds that have shown a very relevant biological activity and with potential application to Alzheimer's disease, whose diffusion will be preserved as it is being evaluated for intellectual protection by of the Bosch i Gimpera Foundation. In the third chapter, the synthetic studies resulting from the in-depth study of a multicomponent reaction that has given rise to a family of compounds with antiproliferative activity in a glioblastoma cell line are presented. This activity is similar to that of the drug used in the first line of treatment and, therefore, preliminary studies have been carried out that have made it possible to characterize the representative compound, promoting its development at the preclinical level. In the fourth chapter, a family of compounds that inhibit an enzyme directly related to inflammatory processes is provided. This new family has improved metabolic characteristics compared to previous families developed in the group and that were the subject of intellectual protection. The fifth chapter includes results derived from joint work with collaborating research groups, aimed at finding new applications for both compounds already previously published by us, with which we continue to work, and new compounds that we are developing. [spa] La síntesis de compuestos orgánicos heterocíclicos permite acceder a un amplio arsenal de compuestos con potencial actividad farmacológica. El presente manuscrito se enmarca en el campo de la química farmacéutica, desarrollando nuevas estrategias terapéuticas mediante el diseño, síntesis y evaluación farmacológica de diversas familias de compuestos orientadas al tratamiento de enfermedades que no tienen una solución terapéutica actualmente. Después de una recopilación publicaciones y congresos en los que se ha realizado difusión de los resultados, en la introducción se comenta cuál es la problemática en relación a las enfermedades no cubiertas farmacológicamente y las posibles soluciones y, se comentan los objetivos que han guiado el trabajo realizado en los 5 capítulos que componen la Tesis. En el primer capítulo, se explican los pasos seguidos para el desarrollo, en su fase preclínica, de un compuesto representativo que fue objeto de protección intelectual por parte de la Fundació Bosch i Gimpera (UB). En el segundo capítulo, se exponen los estudios sintéticos resultantes de la exploración de la reactividad de diferentes posiciones de la familia de α-iminofosfonatos bicíclios que han permitido acceder a nuevas estructuras que han sido sometidas a evaluación farmacológica. En concreto, se ha podido acceder a una familia de compuestos que han mostrado una actividad biológica muy relevante y con potencial aplicación a la enfermedad de Alzheimer, de la que se preservará su difusión por estar siendo objeto de evaluación para la su protección intelectual por parte de la Fundación Bosch i Gimpera. En el tercer capítulo, se presentan los estudios sintéticos resultantes del estudio en profundidad de una reacción multicomponente que ha dado lugar a una familia de compuestos con actividad antiproliferativa en una línea celular de glioblastoma. Esta actividad es similar a la del fármaco que se utiliza en la primera línea de tratamiento y, por tanto, se han realizado estudios preliminares que han permitido caracterizar el compuesto representativo propulsando su desarrollo a nivel preclínico. En el cuarto capítulo se aporta una familia de compuestos inhibidores de una enzima directamente relacionada con procesos inflamatorios. Esta nueva familia posee unas características metabólicas mejoradas respecto a familias anteriores desarrolladas en el grupo y que fueron objeto de protección intelectual. En el quinto capítulo, se incluyen resultados derivados del trabajo conjunto con grupos de investigación colaboradores, orientados a la búsqueda de nuevas aplicaciones tanto de compuestos ya publicados previamente por nosotros, con los que seguimos trabajando, como nuevos compuestos que estamos desarrollando. Al final de la memoria, en una sección anexa, se adjuntan publicaciones en revistas del ámbito de la química médica y farmacología de las que soy coautora pero que no son el objetivo principal de la Tesis. Es importante destacar que la Tesis recoge un trabajo multidisciplinar en el que han participado grupos de investigación muy relevantes a nivel nacional e internacional y diversas instituciones.

The diastereo- and enantioselective dearomative formal [3 + 2] cycloaddition of 2-nitrobenzofurans and α-aryl-α-isocyanoacetate esters provides tricyclic compounds bearing the 3a,8b-dihydro-1H-benzofuro[2,3-c]pyrrole framework with three consecutive stereogenic centers. The reaction was enabled by a cupreine-ether organocatalyst. The reaction products were obtained with almost full diastereoselectivity and with excellent enantiomeric excesses for a number of substituted 2-nitrobenzofurans and isocyanoacetates.

[eng] The health promoting attributes associated with following a traditional Mediterranean diet have been reviewed extensively. The principal source of dietary fat in the Mediterranean diet is Extra virgin olive oil (EVOO) that contribute significantly to the superior health profile observed in Mediterranean populations. Between its minors compounds, EVOO contains at least 30 phenolic compounds (PCs) and has been classified according to their chemical structure into the following main classes: phenolic acids, lignans, flavonoids, phenolic alcohols, secoiridoids (SEC). Regarding this last group, these compounds are responsible for the sensory features of EVOO, mainly the bitter and pungent mouthfeel. Oleocanthal (OLC) and oleacein (OLEA) appear the main compounds responsible for the mouthfeel perceptions, respectively. Moreover, they are the most studied and best-known components in terms of health protecting activities. In this sense, the potential protective role exerted by SECs from EVOO in cancer, cardiovascular, neurodegenerative, aging‐related, and immunoinflammatory diseases has been studied. The data obtained so far has clearly shown that SECs has proven biological activity, including antioxidant and antimicrobial properties, anti-inflammatory effects, anticancer properties and neuro- protective effects, among others. The phenolic concentration and composition of EVOO together with the degree to which these components are absorbed and metabolized are essential in determining the health effects associated with such compounds. Several factors have been shown to affect the concentration of PCs in EVOO and these include olive fruit cultivar and variety, region of growth, agricultural cultivation techniques, maturity at harvest, processing, and storage. In this thesis the study of the main factors affecting the PCs concentration is covered. Regarding its bioavailability after EVOO dietary intake has been a topic of increasing research in recent years. Bioavailability is a complex process involving several different stages that include liberation, absorption, distribution, metabolism and elimination phases. For polyphenols, this principally involves the following digestive processes: i) release of polyphenols from the food matrix; ii) changes in PCs during gastric/small-intestinal digestion; iii) cellular uptake of aglycons and some conjugated polyphenols by enterocytes; iv) microbiological fermentation of nonabsorbed polyphenols or those re-excreted via bile or the pancreas to yield additional metabolites, v) phase I/II enzyme modifications that occur upon uptake in the small intestine and/or colon; vi) transport in the bloodstream and subsequent tissue redistribution; and vii) excretion via the kidney or re-excretion into the gut via bile and pancreatic juices. Since many in vitro, in situ, in vivo and clinical studies, have demonstrated the protective effect of SECs, in this thesis we set out to evaluate the intestinal absorption and metabolism of OLC and OLEA for a better understanding of the biological effects attributed to these compounds. In addition, a tissue distribution of OLC and OLEA and its metabolites also was study after the oral administration of enriched refined olive oil. Target tissues likes as brain, hearth, lungs, among other were evaluated to determine the biological concentrations usually achieved when following a Mediterranean diet.

A novel bio-based flame retardant (Phytic acid - trometamol, PA-THAM) was prepared via salt formation reaction between phytic acid and trometamol. The chemical structure and thermal stability of this novel phytate were characterized by Nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA). Afterward, the effect of PA-THAM on the flammability of PLA was investigated. On the basis of the results, 3 wt% incorporation of PA-THAM in PLA exhibited better results than pure PLA in flame combustion tests, for example, LOI value increased from 19.9 to 25.8% and ratings in UL-94 varied from No Rating to V-0 rating. This ignitionresistance performance was analyzed investigating the relationship between properties and structure. The results elucidated that the incorporation of PA-THAM significantly reduced the molten viscosity of biocomposite, which facilitated the 'heat transfer' effect to rapidly decrease the surface temperature. In comparison with neat PLA, the same load of PA-THAM in PLA had little effect on the mechanical properties of PLA-based biocomposite, which indicated that the optimum load of PA-THAM maintained the balance of fire retardancy and mechanical properties of the PLA biocomposite.

The enantioselective 1,4-alkynylation of conjugated imines derived from saccharin with aryl- and alkyl-substituted terminal alkynes has been achieved. The reaction mediated by diethylzinc in the presence of a catalytic amount of a bis(hydroxy)malonamide chiral ligand provides the corresponding imines bearing a propargylic stereocenter with moderate yields and fair to excellent enantioselectivities.

L’objectiu experimental d’aquest treball és l’estudi de la dinàmica i l’estabilitat de dos compostos: el 2- bencilfenol, un reactiu utilitzat per la síntesis d’altres compostos a la indústria química, i el mitotane, un fàrmac utilitzat a la indústria farmacèutica generalment pel tractament de malalties associades a alteracions hormonals. Per a dur a terme aquest estudi es realitzen fonamentalment dues tècniques experimentals, la calorimetria diferencial d’escombrat (DSC) i la tècnica d’espectroscòpia dielèctrica. La tècnica de la calorimetria diferencial d’escombrat es una tècnica termoanalítica que s’ha utilitzat per identificar i estudiar les transformacions físiques que es tenen lloc en un compost en funció de la temperatura, el valor de la variació entàlpica associada als canvis de fase i les temperatures a les que es produeixen aquestes transformacions. La tècnica de l’espectroscòpia dielèctrica s’utilitza per mesurar les propietats dielèctriques del compost i la dinàmica de relaxació en un rang de freqüències determinat. D’aquesta manera es pot registrar el temps de resposta (temps de relaxació) dels dipols presents la substància per reorientar-se en la direcció del camp elèctric aplicat sobre la mostra en qüestió. Es pot conèixer la dinàmica de la fase amorfa d’un compost a partir dels temps de relaxació i la seva dependència amb la temperatura. Els resultats mostren dos pics de relaxació pel 2-bencilfenol: un lligat a la relaxació primària α i un pic lligat a la relaxació secundària β. Pel mitotane els resultats obtinguts mostren tres pics de relaxació diferents: Un pic de relaxació primària α i dos pics de relaxació secundària β y γ. A la present literatura s’interpreten i es discuteixen les possibles causes de l’origen d’aquests pics a partir dels resultats i l’anàlisi de l’estructura molecular del compost. Finalment, s’ha decidit introduir un estudi de la cinètica de la cristal·lització dels dos compostos, a causa de la recurrència de l’aparició d’aquest fenomen durant l’estudi de la fase amorfa. Per a dur a terme aquest estudi s’ha examinat el procés de cristal·lització per les dues substàncies a dues temperatures diferents, de manera que es pot comparar la morfologia dels cristalls formats i els mecanismes de cristal·lització en funció de la temperatura. El objetivo experimental de este trabajo es el estudio de la dinámica y la estabilidad de dos compuestos: el 2-bencilfenol, un reactivo utilizado para la síntesis de otros compuestos en la industria química, y el mitotano, un fármaco utilizado en la industria farmacéutica generalmente para el tratamiento de enfermedades asociadas a alteraciones hormonales. Para llevar a cabo este estudio se realizan fundamentalmente dos técnicas experimentales, la calorimetría diferencial de barrido (DSC) y la técnica de espectroscopia dieléctrica. La técnica de la calorimetría diferencial de barrido es una técnica termoanalítica que se ha utilizado para identificar y estudiar las transformaciones físicas que se dan en un compuesto en función de la temperatura, el valor de la variación entálpica asociada a los cambios de fase y las temperaturas a las que se llevan a cabo dichas transformaciones. La técnica de la espectroscopia dieléctrica se utiliza para medir las propiedades dieléctricas del compuesto y la dinámica de relajación en un rango de frecuencias determinado. De esta manera se puede registrar el tiempo de respuesta (tiempo de relajación) de los dipolos presentes en una sustancia para reorientarse en la dirección del campo eléctrico alterno aplicado sobre la muestra en cuestión. Se puede conocer la dinámica de la fase amorfa de un compuesto a partir de los tiempos de relajación y su dependencia con la temperatura. Los resultados muestran dos picos de relajación para el 2-bencilfenol: Uno ligado a la relajación primaria α, asociada al movimiento cooperativo de las moléculas y uno ligado a la relajación secundaria β, del cual se estudia y se discute su origen. Para el mitotano los resultados obtenidos muestran tres picos de relajación diferentes: Un pico de relajación primario α y dos picos de relajación secundarios β y γ. En la presente literatura se interpretan y se discuten las posibles causas del origen de estos picos a partir de los resultados y el análisis de la estructura molecular del compuesto. Finalmente, se ha decidido introducir un estudio de la cinética de la cristalización de ambos compuestos, debido a la recurrencia de la aparición de este fenómeno durante el estudio de la fase amorfa. Para llevar a cabo este estudio se ha examinado el proceso de cristalización para las dos sustancias a dos temperaturas distintas, pudiendo comparar de esta manera la morfología de los cristales formados y los mecanismos de cristalización en función de la temperatura. The experimental objective of this work is the study of the dynamics and stability of two compounds: 2-benzylphenol, a reagent used for the synthesis of other compounds in the chemical industry, and mitotane, a drug used in the pharmaceutical industry generally for the treatment of diseases associated with hormonal alterations. To carry out this study, two experimental techniques are mainly carried out: the differential scanning calorimetry (DSC) and the dielectric spectroscopy technique. The technique of differential scanning calorimetry is a thermoanalytic technique that has been used to identify and study the physical transformations that occur in a compound as a function of temperature, the value of the entopic variation associated with phase changes and the temperatures at which these transformations are carried out. The dielectric spectroscopy technique is used to measure the dielectric properties of the compound and the relaxation dynamics in a given frequency range. In this way it is possible to register the response time (relaxation time) that it takes the dipoles present in a substance to reorient in the direction of the alternating electric field applied on the sample. The dynamics of the amorphous phase of a compound can be known from relaxation times and their dependence on temperature. The results show two peaks of relaxation for 2-benzylphenol: One linked to primary relaxation α, associated with the cooperative movement of molecules and the other one linked to secondary relaxation β, of which its origin is studied and discussed. For mitotane the results obtained show three different relaxation peaks: A primary relaxation peak α and two secondary relaxation peaks β and γ. In the present literature the possible causes of the origin of these peaks are interpreted and discussed from the results and analysis of the molecular structure of the compound. Finally, it has been decided to introduce a study of the kinetics of the crystallization of both compounds, due to the recurrence of the appearance of this phenomenon during the study of the amorphous phase. In this study it has been examined the crystallization process for the two substances at two different temperatures, being able to compare in this way the morphology of the crystals formed and the crystallization mechanisms depending on the temperature.

The spirocyclic motif is present in natural products, chiral ligands, and compounds of pharmacological interest. Isothiocyanates as well as isocyanides bearing electron-withdrawing groups in the α-position can be deprotonated and react as formal dipoles on account of the presence of a nucleophilic carbanion and an electrophilic atom in the isothiocyanate or isocyanide functional groups. In the last years a number of procedures involving the formal [3+2] cycloaddition reaction of isothiocyanates or isocyanides with cyclic compounds bearing electrophilic exocyclic double bonds have been developed for the enantioselective synthesis of aza-spirocyclic compounds. Among them, organocatalysis has played a predominant role in the development of asymmetric versions for these reactions. The synthesis of spirooxindoles by using this methodology has received especial attention, although other spirocyclic scaffolds are available depending on the structure of the dipolarophiles and the formal isothiocyanate and isocyanide dipoles.

Little is known about the quantity and quality of dissolved organic matter (DOM) in waters from continental geothermal systems, with only a few reports available from the Yellowstone US National Park. In this study, we explored the chemodiversity of DOM in water samples collected from two geothermal hot springs from the Kenyan East African Rift Valley, a region extremely rich in fumaroles, geysers, and spouting springs, located in close proximity to volcanic lakes. The DOM characterization included in-depth assessments performed by negative electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Reduced, saturated and little aromatic DOM compounds were dominant in the hot spring waters collected from either the Ol Njorowa gorge (ON) or the south shore of the soda-saline Lake Elementaita (ELM). Oxygen-poor and sulfur-bearing DOM molecules prevailed in ON, probably reflecting abiotic sulfurization from sulfide-rich geofluids. Nitrogen-bearing aliphatic and protein-like molecules were abundant in ELM, possibly perfusing through the organic-rich sediments of the adjacent Lake Elementaita. Notably, the heat-altered DOM of ancient autochthonous derivation could represent an overlooked source of aliphatic organic carbon for connected lentic environments, with a potential direct impact on nutrient cycling in lakes that receive geothermal water inputs.

Dissolved organic matter (DOM) composition exerts a direct control on its degradation and subsequent persistence in aquatic ecosystems. Yet, under certain conditions, the degradation patterns of DOM cannot be solely explained by its composition, highlighting the relevance of environmental conditions for DOM degradation. Here, we experimentally assessed the relative influence of composition vs. environment on DOM degradation by performing degradation bioassays using three contrasting DOM sources inoculated with a standardized bacterial inoculum under five distinct environments. The DOM degradation kinetics modeled using reactivity continuum models showed that composition was more important than environment in determining the bulk DOM decay patterns. Changes in DOM composition resulted from the interaction between DOM source and environment. The role of environment was stronger on shaping the bacterial community composition, but the intrinsic nature of the DOM source exerted stronger control on the DOM degradation function Research Funding: Agència de Gestió d'Ajuts Universitaris i de Recerca. Grant Number: BP2016‐00215 European Commission. Grant Number: Marie Sklodowska‐Curie 839709 Ministerio de Ciencia e Innovación. Grant Number: FJC2018‐037791‐I Spanish Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER). Grant Number: FEDER‐MCIU‐AEI/CGL2017‐86788‐C3 Spanish Ministry of Economy and Competitiveness. Grant Number: CGL2014‐61771‐EXP

Proteins need to interconvert between many conformations in order to function, many of which are formed transiently, and sparsely populated. Particularly when the lifetimes of these states approach the millisecond timescale, identifying the relevant structures and the mechanism by which they interconvert remains a tremendous challenge. Here we introduce a novel combination of accelerated MD (aMD) simulations and Markov state modelling (MSM) to explore these ‘excited’ conformational states. Applying this to the highly dynamic protein CypA, a protein involved in immune response and associated with HIV infection, we identify five principally populated conformational states and the atomistic mechanism by which they interconvert. A rational design strategy predicted that the mutant D66A should stabilise the minor conformations and substantially alter the dynamics, whereas the similar mutant H70A should leave the landscape broadly unchanged. These predictions are confirmed using CPMG and R1ρ solution state NMR measurements. By efficiently exploring functionally relevant, but sparsely populated conformations with millisecond lifetimes in silico, our aMD/MSM method has tremendous promise for the design of dynamic protein free energy landscapes for both protein engineering and drug discovery., Molecular simulations were used to design large scale loop motions in the enzyme cyclophilin A and NMR and biophysical methods were employed to validate the models.

The chemistry of strained unsaturated cyclic compounds has experienced remarkable growth in recent years via the development of metal–free click reactions. Among these reactions, the cycloaddition of cyclopropenes and their analogues to ortho-quinones has been established as a highly promising click reaction. The present work investigates the mechanism involved in the cycloaddition of strained dienes to ortho-quinones and structural factors that would influence this reaction. For this purpose, we use B97D density functional theory calculations throughout, and for relevant cases, we use spin component–scaled MP2 calculations and single–point domain-based local pair natural orbital coupled cluster (DLPNO-CCSD(T)) calculations. The outcomes are analyzed in detail using the distortion/interaction model, and suggestions for future experimental work are made.

Objectius de Desenvolupament Sostenible::3 - Salut i Benestar

Wide bandgap organic-inorganic hybrid perovskites (OIHPs) have shown great potential to improve the efficiency of tandem solar cells. Furthermore, a perovskite absorption layer with excellent surface morphology, i.e. smooth surface, and large grain size is crucial for fabricating efficient perovskite solar cells (PSCs). In this work, both compositional and solvent engineering are performed to improve the quality of the perovskite absorption layer and reach a better photovoltaic performance. This study includes a characterization of both the material and the devices themselves (absorbance and photoluminescence spectroscopy and J-V curves). In order to improve the optical and morphological properties of the wide bandgap perovskites, the behaviour of different antisolvents are studied: common antisolvents (e.g. Chlorobenzene), green antisolvents (e.g. Methyl Benzoate) and mixtures of antisolvents. As a result, Methyl Benzoate (MB) and a mixture of MB with Hexane are promising antisolvents for engineering high-quality perovskites layers. Outgoing

Herein we report an efficient synthesis to prepare O‐doped nanographenes, which derive from the longitudinally and latitudinally p‐extension of pyrene. The derivatives are highly fluorescent and feature low‐oxidation potentials. Exploiting electrooxidation, crystals of cationic mixed valence (MV) complexes were grown in which the organic salts organize into face‐to‐face p‐ p stacks, a favorable solid‐state arrangement for organic electronics. Variable‐temperature EPR measurements and relaxation studies suggest a strong electron delocalization along the longitudinal axis of the columnar p‐stacking architectures. Electric measurements of single crystals of the MV salts exhibited a semiconducting behavior with a remarkable high conductivity at room temperature. These findings further support the idea for which the p‐extension of polycyclic aromatic hydrocarbons featuring precise heteroatom doping topologies, is an attractive approach to enable nanographenes with a broad spectrum of semiconducting properties and high charge mobilities.

This work aims at proposing and validating a model that can be exploited for the future development of industrial applications (e.g., process design and control) of Fenton and photo-Fenton processes. Hence, a compromise modeling solution has been developed between the non-generalizable accuracy of the first principles models (FPMs) and the oversimplification of the empirical models (EMs). The work presents a novel model of moderate complexity that is simplified enough to be generalizable and computationally affordable, while retaining physical meaning. The methodology is based on a general degradation mechanism that can be algorithmically generated from the carbon number of the target compound, as well as from the knowledge of two kinetic parameters, one for the faster initial rate and the other one for the subsequent degradation steps. The contaminant degradation mechanism has been combined with an appropriately simplified implementation of the well-known Fenton and photo-Fenton kinetics. This model describes the degradation not only of the target compound and of the oxidant, but also of total organic carbon (TOC), which is used to define the overall quality of the water. Experimental design techniques were used along with a non-conventional modeling methodology of programmable process structures (PPS). This novel modeling approach was applied and validated on the degradation of three model compounds. A successful prediction of the evolution of the contaminants H2O2 and TOC was confirmed and assessed by the root mean square error (RMSE).

[cat] Aquesta tesi descriu el disseny, optimització i implementació de metodologies d’screening versàtils per a la recerca de noves formes sòlides de compostos orgànics. La certesa d’estar desenvolupant la forma sòlida d’un principi actiu més adient per a ser formulada només es pot tenir quan es realitza un estudi complert de l’estat sòlid del compost. El coneixement de quines són les diferents formes sòlides en les que pot existir un compost, de les interaccions intermoleculars que estabilitzen les seves xarxes cristalꞏlines, així com la manera d’obtenir-les i la seva caracterització són els objectius de l’estudi de l’estat sòlid d’un compost. En aquest treball s’ha establert una metòdica de treball semi-automàtica de cerca de noves formes sòlides que és capaç d’adaptar-se a les demandes de la indústria farmacèutica i que a l’hora és modulable en el temps, en funció del progrés de l’estudi. El disseny i l’optimització de les metodologies d’screening s’han desenvolupat a partir de la combinació dels coneixements multidisciplinaris adquirits de diferents àrees com són els estudis d’estat sòlid, la cristalꞏlografia i l’enginyeria cristalꞏlina. L’aplicació i validació qualitativa de les metodologies s’ha realitzat a través de l’estudi de tres casos pràctics amb compostos amb interès farmacèutic. S’han descobert 48 noves fases cristalꞏlines: polimorfs, solvats, sals, híbrids i cocristalls dels tres principis actius estudiats i s’han resolt i analitzat 20 estructures cristalꞏlines. Per a l’anàlisi i caracterització dels diferents sòlids cristalꞏlins descoberts s’han utilitzat diferents tècniques experimentals com la calorimetria diferencial d’escaneig, la termogravimetria, l’espectroscòpia de ressonància magnètica nuclear, la difracció de raigs X de pols i de monocristall, la sorció dinàmica de vapors i la termomicroscòpia. El gran nombre de formes sòlides descobertes dels tres principis actius ha permès aprofundir en l’estudi de diversos fenòmens de gran rellevància dins del camp de l’estat sòlid farmacèutic: la generació de formes sòlides a partir de la desolvatació de solvats que emmascaren la seva existència, el morfotropisme, la formació de compostos híbrids sal-cocristall, les interaccions intermoleculars anió-anió o la constatació que l’aparició de productes secundaris condicionen la recerca de noves formes sòlides, [eng] This Thesis describes the design, optimization and implementation of screening methodologies for the research of new solid forms or organic compounds. It is possible to be sure about the most suitable solid form of an API to be developed only when a comprehensive solid-state study has been conducted. The main objective of such a study is to understand the polymorphic landscape, the intermolecular interactions that stabilize the crystal lattice together with the methodologies to prepare the solid forms of interest. In this work, a semi-automatic work methodology for the research of new solid forms adaptable to the pharmaceutical industry needs has been developed starting from a combination between multidisciplinary knowledge in the areas of crystallography and crystal engineering. The application and qualitative validation of the methodologies has been conducted through the study of three active pharmaceutical ingredients. In this sense, 48 new crystal forms (polymorphs, solvates, salts, hybrid salt/cocrystals and cocrystals) have been discovered and 20 crystal structures have been solved. Differential scanning calorimetry, thermogravimetry, powder and single crystal X-ray diffraction, nuclear magnetic ressonance, thermomicroscopy and dynamic vapour sorption have been used to analyse and characterize the new solid forms. The high number of new solid forms discovered in this work has allowed to get a deeper insight in phenomena of great relevance in the field of pharmaceutical solid state, such as the production of new solid forms from solvates, the morphotropism, the formation of hybrid salt/cocrystals, the anion/anion intermolecular interaction and the importance of secondary products for the discovery of new solid forms., [spa] Esta tesis describe el diseño, optimización e implementación de metodologías de screening versátiles para la búsqueda de nuevas formas sólidas de compuestos orgánicos. La certeza de estar desarrollando la forma sólida de un principio activo más adecuada para ser formulada sólo se puede tener cuando se realiza un estudio completo del estado sólido del compuesto. El conocimiento sobre cuáles son las diferentes formas sólidas en las que puede existir un compuesto, de las interacciones intermoleculares que estabilizan sus redes cristalinas, así como la manera de obtenerlas y su caracterización, son los objetivos del estudio de estado sólido del mismo. En este trabajo se ha establecido una metódica de trabajo semi-automática de búsqueda de nuevas formas sólidas que es capaz de adaptarse a las demandas de la industria farmacéutica y que a su vez es modulable en el tiempo, en función del progreso del estudio. El diseño y optimización de las metodologías de screening se han desarrollado a partir de la combinación de los conocimientos multidisciplinares adquiridos de diferentes áreas como son los estudios de estado sólido, la cristalografía y la ingeniería cristalina. La aplicación y verificación cualitativa de las metodologías se ha realizado a través del estudio de tres casos prácticos con compuestos de interés farmacéutico. Se han descubierto 48 nuevas fases cristalinas: polimorfos, solvatos, sales, híbridos y cocristales de los tres principios activos estudiados y se han resuelto y analizado 20 estructuras cristalinas. Para el análisis y caracterización de los diferentes sólidos cristalinos descubiertos se han utilizado diferentes técnicas experimentales como la calorimetría diferencial de barrido, termogravimetría, espectroscopía de resonancia magnética nuclear, difracción de rayos X de polvo y de monocristal, sorción dinámica de vapor y termomicroscopía. El gran número de formas sólidas descubiertas de los tres principios activos ha permitido profundizar en el estudio de diversos fenómenos de gran relevancia dentro del campo del estado sólido farmacéutico: la generación de formas sólidas a partir de la desolvatación de solvatos que enmascaran su existencia, el morfotropismo, la formación de compuestos híbridos sal- cocristal, las interacciones intermoleculares anión-anión o la constatación de que la aparición de productos secundarios condicionan la búsqueda de nuevas formas sólidas.

The study of the reactivity of three 2-phenyl-3H-indole ligands of general formulae C8H3N-2-(C6H4-4-R1)-3-NOMe-5-R2 (1) [with R1 = H, R2 = OMe (a), R1 = R2 = H (b) or R1 = Cl, R2 = H (c)] with [Pd(&eta, 3-1-R3C3H4)(&mu, Cl)]2 (R3 = H or Ph) has allowed us to isolate two sets of new Pd(II)-allyl complexes of general formulae [Pd(&eta, 3-1-R3C3H4)(1)Cl] {R3 = H (2) or Ph (3)}. Compounds 2a&ndash, 2c and 3a&ndash, 3c were characterized by elemental analyses, mass spectrometry and IR spectroscopy. The crystal structures of 2a, 3a and 3b were also determined by X-ray diffraction. 1H-NMR studies reveal the coexistence of two (for 2a&ndash, 2c) or three (for 3a&ndash, 3c) isomeric forms in CD2Cl2 solutions at 182 K. Additional studies on the catalytic activity of mixtures containing [Pd(&eta, 3-C3H5)(&mu, Cl)]2 and the parent ligand (1a&ndash, 1c) in the allylic alkylation of (E)-3-phenyl-2-propenyl (cinnamyl) acetate with sodium diethyl 2-methylmalonate as well as the stoichiometric reaction between compounds 3a and 3c with the nucleophile reveal that in both cases the formation of the linear trans- derivative is strongly preferred over the branched product. Computational studies at a DFT level on compound 3a allowed us to compare the relative stability of their isomeric forms present in solution and to explain the regioselectivity of the catalytic and stoichiometric processes.

Graphene has been covalently functionalized through a one-pot reductive pathway using graphite intercalation compounds (GICs), in particular KC8 , with three different orthogonally protected derivatives of 4-aminobenzylamine. This novel multifunctional platform exhibits excellent bulk functionalization homogeneity (Hbulk ) and degree of addition while preserving the chemical functionalities of the organic addends through different protecting groups, namely: tert-butyloxycarbonyl (Boc), benzyloxycarbonyl (Cbz) and phthalimide (Pht). We have employed (temperature-dependent) statistical Raman spectroscopy (SRS), X-ray photoelectron spectroscopy (XPS), magic angle spinning solid state 13 C NMR (MAS-NMR), and a characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spectrometry (TG-GC-MS) to unambiguously demonstrate the covalent binding and the chemical nature of the different molecular linkers. This work paves the way for the development of smart graphene-based materials of great interest in biomedicine or electronics, to name a few, and will serve as a guide in the design of new 2D multifunctional materials.

The microbial decomposition of organic matter is a fundamental ecosystem process that transforms organic matter and fuels detritus-based food webs, influencing biogeochemical cycles such as C-cycling. The efficiency of this process can be compromised during the non-flow periods of intermittent and ephemeral streams (IRES). When water flow ceases, sediments represent the last wet habitat available to microorganisms and may play an important role in sustaining microbial decomposition. However, despite the increasing prevalence of IRES due to climate change and water abstraction, it is unclear to what degree the subsurface habitat can sustain microbial decomposition during non-flow periods. In order to gather information, we selected 20 streams across Catalonia (Spain) along a gradient of flow intermittency, where we measured microbial decomposition and fungal biomass by placing wood sticks in both the surface and subsurface zones (15 cm below the streambed) over the course of one hydrological year. Our results showed that microbial decomposition and fungal biomass were consistently greater in the subsurface zone than in the surface zone, when intermittency increased. Although flow intermittency was the main driver of both microbial decomposition and fungal biomass, phosphorus availability in the water, sediment C:N ratio and sediment grain size also played relevant roles in surface and subsurface organic matter processing. Thus, our findings demonstrate that although the OM processing in both zones decreases with increased intermittency, the subsurface zone made an important contribution during the non-flow periods in IRES. Therefore, subsurface activity during non-flow periods has the potential to affect and maintain ecosystem functioning.

The efficient use by crops of nitrogen from manures is an agronomic and environmental issue, mainly in double-annual forage cropping systems linked to livestock production.A six-year trial was conducted for a biennial rotation of four forage crops: oat-sorghum (first year) and ryegrass-maize (second year) in a humid Mediter ranean area. Ten fertilization treatments were introduced: a control (without N);two minerals equivalent to 250 kg N ha-1yr-1 applied at sowing or as sidedressing; dairy cattle manure at a rate of 170, 250 and 500 kg N ha-1yr-1 and four treatments where the two lowest manure rates were supplemented with 80 or 160 kg mineral N ha -1 yr -1.They were distributed according to a randomized block design with three blocks. The highest N mineral soil content was found in the summer of the third rotation, in plots where no manure was applied. The yearly incorporation of manure reduced, in successive cropping seasons, the amount of additional mineral N n eeded as sidedressing to achieve the highest yields.Besides, in the last two years, there was no need for mineral N application for the manure rate of 250 kg N ha -1yr-1. This amount always covered the oat-sorghum N uptake. In the ryegrass-maize sequence uptakes were as high as 3 kg N ha-1yr-1.In the medium term, the intermediate manure rate (250 kg N ha -1 yr -1) optimizes nutrient recycling within the farming system, and it should be considered in the analysis ofthresholds for N of organic orig in to be applied to systems with high N demand.

The use of composts and vermicomposts as adsorbents is an important topic of study in the field of environmental remediation. These materials are rich in organic matter and have functional groups that can interact with organic and inorganic compounds. They also contain microorganisms that can promote biodegradation of organic substances. Composts that cannot be used for agronomic purposes (owing to e.g. low nutrient levels or phytotoxicity) may be valuable for soil remediation or pollutant removal. In this review, we discuss papers on this topic, with the objective of drawing attention to the potential use of composts/vermicomposts and to recommend further investigation on this subject. Few published studies have investigated the use of composts/vermicomposts to remove dyes and other coloured compounds. However, preliminary results show that these materials are potentially good adsorbents, at least comparable to other low-cost adsorbents, and that, in general, basic dyes are more efficiently removed than direct, reactive or acid dyes. The results of the works reviewed also show that dye removal takes place by adsorption mechanisms, in most studies following a Langmuir model, and that the kinetics of removal are fast and follow a pseudo-second order model. However, there remain several uncertainties regarding this application. For example, very few dyes have been studied so far, and little is known about the influence of the properties of composts/vermicomposts on the dye removal process. Moreover, the possible use of compost/vermicompost to enhance biodegradation processes has not been explored. All these questions should be addressed in future research.

[cat] Avui dia, l’espectrometria de masses és una eina indispensable en molts laboratoris analítics que treballen en els camps d’aplicació d’alimentació, medi ambient, d’anàlisi forense així com per a l’anàlisi clínica per al diagnòstic de malalties. Les excel·lents prestacions d’aquesta tècnica en termes de sensibilitat i de selectivitat i la gran quantitat d’informació estructural que se n’obté faciliten la identificació inequívoca d’una gran varietat de compostos orgànics en tot tipus de matrius. Així, el desenvolupament de mètodes analítics ràpids, senzills i versàtils que permetin donar una resposta gairebé immediata al problema analític que es planteja són de gran interès per millorar la productivitat d’aquests laboratoris i per facilitar la presa de decisions diagnòstiques. És per aquest motiu que aquesta tesi està centrada en un nou grup de tècniques d’ionització a pressió atmosfèrica anomenat Ambient Ionization Mass Spectrometry (Ambient MS), les quals possibiliten l’anàlisi directa de tot tipus de mostres sense o amb una mínima manipulació i permeten obtenir informació molecular rellevant gairebé en temps real. En aquesta tesi s’ha estudiat l’aplicabilitat de la tècnica d’ionització per desorció per electroesprai (DESI) combinada amb l’espectrometria de masses d’alta resolució, per a l’anàlisi de compostos sospitosos i desconeguts en matrius d’elevada complexitat. S’ha establert un mètode de cribratge de mostres per a la identificació de drogues veterinàries en pinsos com a conseqüència d’una contaminació creuada i s’ha caracteritzat un producte fitosanitari sospitós d’haver-se adulterat i del qual se’n desconeixia la seva naturalesa química. S’han avaluat diferents estratègies de manipulació ràpides (, [eng] Nowadays, mass spectrometry is an indispensable tool in many application fields for food, environmental, forensic and for clinical analysis. This thesis is focused on a new family of mass spectrometric techniques called Ambient Ionization Mass Spectrometry (Ambient MS), which enable the direct analysis of samples with minimal or without any sample manipulation, providing relevant molecular information data almost in-real time. The applicability of desorption electrospray ionization (DESI) combined with high- resolution mass spectrometry (HRMS) has been evaluated for non-target analysis and for the identification of unknown compounds in complex samples. A DESI-HRMS method has been developed for the identification of veterinary drugs in cross-contaminated feedstuffs and for the characterization of unknown compounds in an adulterated phytosanitary product. Several fast sample manipulation strategies have been evaluated and DESI and Q-Orbitrap working conditions have been optimized to achieve accurate mass measurements and suitable sensitivity and selectivity. Furthermore, several approaches such as custom-made databases or Kendrick mass defect analysis have been applied for the rapid interrogation of mass spectral raw data. Modified touch spray (TS) and paper spray (PS) techniques have also been evaluated. A TS-MS method using commercial medical swabs has been developed to provide relevant diagnostic molecular information for brain cancer. Moreover, PS has been combined with atmospheric pressure photoionization (PS-APPI) for the direct determination of neutral polyfluorinated alkyl substances (PFASs) in waterproof impregnation sprays. The best TS and PS-APPI assembly configurations have been evaluated. Among the operational working parameter, solvent composition and spray voltage have been critical in TS for the generation of a stable cone-jet electrospray plume. Instead, in PS-APPI the effect of these parameters is more related to the response of the ions generated by APPI. Phospholipid profiles obtained by swab TS-MS tissue analysis have allowed to discriminate between cancer and normal tissues. Moreover, measurements of two oncometabolites have allowed to qualitatively assess tumor infiltration grade and glioma mutation status. PS-APPI-HRMS method quality parameters have demonstrated the good performance of the proposed method for the quantification of neutral PFASs in waterproof impregnation sprays and the analysis of raw samples revealed the presence of several PFASs at mg L-1 levels.

[cat] Durant les dècades dels anys 50 i 60 del segle XX es van utilitzar arreu del món diferents tipus de compostos organoclorats i organobromats, que pertanyen als contaminants orgànics persistents (COPs), com a pesticides, retardants de flama o aïllants tèrmics. El 2001 la Convenció d’Estocolm sobre COPs va reconèixer els efectes adversos d’aquestes compostos sobre la salut i el medi ambient i va proposar controls amb l’objectiu d’eliminar o reduir el seu ús. Com a conseqüència d’aquesta prohibició altres compostos s’han anat sintetitzat per substituir-los, alguns d’ells són els pesticides organofosforats i els piretroides, que tot i que no són persistents el fet que s’utilitzin en grans quantitats fa que siguin un risc pel medi ambient i la salut. Aquest estudi avalua, per una banda, l’abast de diferents contaminants orgànics persistents (COPs), especialment els compostos organoclorats (OCs) i els polibromodifenil èters (PBDEs), en dones. I per altra banda, la càrrega i exposició de diferents pesticides organofosforats i piretroides en població general de tres països europeus, dos països on l’agricultura esta molt present per tant s’utilitzen molts pesticides, Espanya i Itàlia, i un en el que es consumeixen menys, Eslovènia. La recerca sobre COPs es centra en dues poblacions de l’Argentina (Salta i Ushuaia) i una de Rússia (Chukotka), Ushuaia i Chukotka es poden considerar remotes. S’ha realitzat una anàlisi química d’un ampli ventall de COPs en mostres de sèrum de dones embarassades, emprant cromatografia de gasos i espectrometria de masses. A més, les concentracions de COPs han estan contrastades amb una sèrie de factors sociodemogràfics. El resultat més destacable es que totes les dones en totes tres poblacions tenen nivells detectables d’algun COP tot i que es van prohibir fa anys. A més, tant la residència de cada una d’elles com l’edat, paritat i l’IMC son uns factors que influencien les concentracions d’OCs. També s’ha trobat una associació positiva entre les concentracions de 4,4’-DDT amb l’edat gestacional, el pes i la longitud dels nadons, suggerint una interacció a nivell metabòlic entre aquest compost i el fetus. L’estudi sobre pesticides organofosforats i piretroides determina la exposició de diferents tipus de poblacions, nens de Trieste (Itàlia), parelles de dones i els seus nens de Ljubljana (Eslòvenia), dones embarassades de Tarragona (Espanya) i població general de zones rurals de Carbia i Sucs a Galícia i Catalunya, respectivament. S’ha desenvolupat una metodologia analítica que permetés les anàlisis dels diferents metabòlits dels pesticides organofosforats i piretroides en l’orina dels grups esmentats. S’ha vist que tant els treballadors agrícoles de Sucs, com les persones que viuen a un entorn rural (Sucs i Carbia) estan més exposats a pesticides organofosforats i piretroides. A més, s’ha trobat una distribució diferent en quant als pesticides organofosforats respecte a altres estudis, el pirimifos té un pes molt important en la població de dones embarassades de Tarragona i nens d’Itàlia. Finalment, s’ha avaluat l’exposició a pesticides organofosforats i piretroides i la seva relació amb la manipulació i utilització d’equips de protecció individual en la població agrícola de Sucs, concloent que l’ús d’EPI es útil i necessari en aquests tipus de treballs., [eng] Over the 50s and 60s different organochlorine and organobromate compounds, classified as persistent organic pollutants, were used all around the world, as pesticides, flame retardants or thermal insulators. In 2001 the Stockholm Convention on POPs recognized their toxicity towards human health and environment and suggested controls with the aim of eliminating and reducing their use. As a consequence new compounds have been synthetized to replace the banned ones, some of them are the organophosphate pesticides (OP) and pyrethroids (PYR). The present research assesses, on one hand, the extent of several persistent organic pollutants (POPs), specifically organochlorine compounds (OCs) and polybrominated diphenyl ethers (PBDEs) in women. And on the other hand, the body burden and exposure of the most important OPs and PYR in general population from three European countries. The study on POPs focuses on two Argentinean populations (Salta and Ushuaia) and one from Russia (Chukotka). A chemical analysis of a wide range of POPs in serum samples from women has been conducted, using gas chromatography and mass spectrometry. Moreover, the POP concentrations were then contrasted with a set of socio-demographic factors. Certain OCs accumulate differently depending on the residence, age, parity and BMI. It has also been found a positive association between 4,4’-DDT with the gestational age, the weight and length of newborns, suggesting a metabolic interaction between this compound and the foetus. The study on OPs and PYR determines the exposure over three different populations, children from Trieste (Italy), mother-child couples from Ljubljana (Slovenia), pregnant women from Tarragona (Spain) and general population from Catalonia and Galicia (Spain). A methodoly has been developed for the quantification of OP and PYR urinary metabolites. A different distribution, according to other studies, has been found, where pirimifos represent an important part of the total OPs in pregnant women from Tarragona and Italian children. Finally, the exposure to these compounds has been assessed according to their manipulation and use among an agricultural population from Catalonia.

[cat] Els materials orgànics moleculars cada vegada tenen més aplicacions en la fabricació de dispositius electrònics per les seves propietats òptiques i de conducció. Quan els elements moleculars són radicals, cal tenir en compte alhora la càrrega i l'espín de l'electró desaparellat. La racionalització de l'estructura i de les propietats d'aquests materials multifuncionals requereix una descripció acurada de la seva estructura electrònica. En aquest treball s'analitza l'aplicabilitat dels models actuals en la modelització de la conducció elèctrica d'aquests materials, emprant tota una família de compostos derivats del bisditiazolil com a sistemes model., [eng] Molecular organic materials are finding increasing application in the manufacture of electronic devices thanks to their optical and conduction properties. When the molecular moieties are radicals, both charge and spin of the unpaired electron should be taken into account. The full rationalization of the structure and properties of these multifunctional materials requires a careful description of their electronic structure. In this paper, the applicability of the current models in the modeling of the electrical conduction of these materials is analyzed, using the family of bisdithiazolyl-based compounds as model systems.

The study of leaf litter as a resource for shredders has emerged as a key topic in trophic links in ecology. However, thus far, most studies have emphasized the leaf quality as one of the main determinants of shredder behaviour and growth without simultaneously considering the leaf quantity availability. Nevertheless, the combined effects of leaf quantity and quality on shredder behaviour and growth is particularly crucial to further understand how ecosystem functioning may respond to the increasing flow intermittency due to climate change. In this study, we explore how changes in the leaf litter quality and quantity influence the feeding preferences and growth of an invertebrate shredder (Potamophylax latipennis). To do so, we used black poplar leaves conditioned in two streams with different flow regimens as a food resource. Afterwards, using a microcosm approach, we offered leaf discs that varied in terms of leaf quantity and quality to P. latipennis. Our results showed that flow intermittency had a negative effect on the quality of the food resource, and a lower quality had a negative effect on the consumption and growth rates of P. latipennis. Furthermore, we found that P. latipennis fed selectively on higher quality leaves even though the availability (quantity) of this resource was lower. In the context of climate change, with higher aridity/drier conditions/scenarios, our findings suggest that a decrease in the availability (quantity) of high-quality resources could potentially threaten links in global fluvial food webs and thus threaten ecosystem functioning.

Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. However, the main issue limiting their applicability is their poor stability in humid conditions. The common methods to overcome this problem involve the formation of strong metal-linker bonds by using highly charged metals, which is limited to a number of structures, the introduction of alkylic groups to the framework by post-synthetic modification (PSM) or chemical vapour deposition (CVD) to enhance overall hydrophobicity of the framework. These last two usually provoke a drastic reduction of the porosity of the material. These strategies do not permit to exploit the properties of the MOF already available and it is imperative to find new methods to enhance the stability of MOFs in water while keeping their properties intact. Herein, we report a novel method to enhance the water stability of MOF crystals featuring Cu(2)(O(2)C)(4) paddle-wheel units, such as HKUST (where HKUST stands for Hong Kong University of Science & Technology), with the catechols functionalized with alkyl and fluoro-alkyl chains. By taking advantage of the unsaturated metal sites and the catalytic catecholase-like activity of Cu(II) ions, we are able to create robust hydrophobic coatings through the oxidation and subsequent polymerization of the catechol units on the surface of the crystals under anaerobic and water-free conditions without disrupting the underlying structure of the framework. This approach not only affords the material with improved water stability but also provides control over the function of the protective coating, which enables the development of functional coatings for the adsorption and separations of volatile organic compounds. We are confident that this approach could also be extended to other unstable MOFs featuring open metal sites.

The anaerobic digestion (AD) consists of a cascade of syntrophic interactions between several microbial groups that result in the breakdown of biodegradable organic matter in the absence of oxygen, resulting in the production of biogas, a CH4 and CO2-rich mixture that can be valorised as renewable energy. The anaerobic digestion process has been engineered for a wide range of applications and current technology developments are aimed towards the so-called co-digestion, the treatment of complex mixtures of organic materials (e.g. slaughterhouse wastes) for an increased biogas yield. Nevertheless, the AD process might be hampered by the inhibitory effect of long chain fatty acids, ammonia and sulphate arising from the hydrolysis of proteins. The main objective of this thesis is to develop innovative techniques and methodologies to degrade protein. As described throughout the following sections, these compounds are potentially inhibitors of AD process, and consequently the production of CH4 and other value-added compounds. These wastes with high concentration of proteins emit high concentrations of NH3 when are degraded. It is reported that in this situation, the main population of methanogenic archaea are inhibited. However, the populations with the ability to carry out the hydrogenotrophic methanogenesis are active in this kind of environments. Therefore, increasing acetate oxidising bacteria populations (SAOB) is possible to achieve a syntrophy relation with some hydrogenotrophic archaea (HMA) populations, in this way is possible to avoid the inhibition caused by the NH3 concentration. Furthermore, sometimes these kind of wastes are associated with rich SO42- compounds that could be easily reduced to sulphide (H2S), molecule that is toxic, corrosive and odorous, producing several problems in the AD process and industrial facilities. The biological reaction that produced these compounds is performed by sulphate-reducing bacteria (SRB). These microbial communities, SRB, have the ability to couple the oxidation of organic matter to the reduction of SO42- outcompeting directly with methane producing archaea (MPA) and homoacetogenic bacteria for common substrates, and inhibiting the CH4 production. In order to carry out this doctoral thesis, two blocks (engineering and microbiological) have been developed that have been integrated as the work progressed. Firstly, different batch-scale studies were carried out in order to monitor the physical-chemical parameters and also the evolution of the microbial communities. In microbiology field, the main objective was to explore the evidence of acetate oxidation via syntrophic interaction between SAOB-HMA. To this end, the abundances of majorities groups were quantified using qPCR analysis based on the 16S rRNA and mcrA genes combined with isotopic compounds. Furthermore, the rapid advancement of high-throughput molecular techniques, as shotgun metagenomics sequencing and binning of scaffolds, have been allowed the implementation of genome-centric approaches that generate comprehensive databases from complex environmental samples, which includes complete or nearly-complete microbial genomes. Secondly, it was necessary that the reactors operated with the appropriate parameters to stablish this syntrophic interaction. As well as, it was also to establish protocols and different parameters concerning the configuration of the reactor based on literature and results obtained from the first set of experiments. Within this block, the hydraulic retention time (HRT), temperature ranges, organic loading rate, reactor configuration was treated. Finally, within this block, the most important point was to found the optimal reactor configuration. As it is known, the structure and the various units that make up a reactor, affect directly the efficiency and optimization of the same. Along this thesis different configurations was tested. La digestió anaeròbia (DA) consisteix en una cascada d’interaccions sintròfiques entre diferents grups de microorganismes que tenen com a principal finalitat la degradació de la matèria orgànica per obtenir biogàs, una barreja de CH4 i CO2 pot ser de gran valor en el camp de les energies renovables. El procés de la DA ha sigut dissenyat per una ampli espectre de residus, (per exemple, restes d’escorxadors) per obtenir un major rendiment de biogàs. No obstant, el procés de la DA es podria veure obstaculitzat per l’efecte inhibitori dels àcids grassos de cadena llarga, la hidròlisi de les proteïnes o els compostos sulfurats. L’objectiu principal d’aquesta tesis es desenvolupar tècniques i mètodes innovadors per la degradació de les proteïnes, principalment. Com es descriu al llarg de les pròximes secciones, aquests compostos son potencialment inhibidores del procés de la DAa, i en conseqüències, de la producció de CH4. Està descrit a la literatura que sota aquestes condicions desfavorables el principal grup de microorganismes productors de CH4 (arquees metanogèniques) es troba total o parcialment inhibit. No obstant, dins d’aquesta gran comunitat de microorganismes existeixen reductes que son capaços de mantenir la activitat metanogènica tot i trobar-se sota aquestes condicions d’inhibició, mitjançant la ruta metanogènica hidrogenotròfica. Aquesta població doncs, ha obert noves possibles vies per la obtenció de biogàs partint d’aquests productes altament inhibitoris. Una d’aquestes opcions, consisteix en incrementar aquelles poblacions que son capaces d’oxidat l’acetat per aconseguir establir una sintròfia amb les poblacions hidrogenotrofiques, evitant així, la inhibició causada per NH3. A més, en moltes ocasions aquest tipus de residus porten associats altes càrregues de compostos sulfurats, el que podria portar posteriorment a una reducció d’aquests compostos a la formació d’àcid sulfhídric (H2S). Aquesta molècula, és tòxica, corrosiva i olorosa, que a més provoca problemes dins del propi procés i és altament perjudicial per les instal·lacions. Aquesta molècula es forma principalment de manera biològica, portada a terme pels bacteris coneguts com sulfato reductors (SRB). Aquestes comunitats, SRB, tenen la capacitat d’acoblar l’oxidació de la matèria orgànica amb la reducció dels compostos sulfurats, competint directament pels substrats comuns amb els arquees hidrogenotrofics i els bacteris homoacetogenics, inhibint així la producció de CH4. Amb la finalitat de desenvolupar aquesta tesis doctoral, s’han portat a terme dos grans blocs experimentals (enginyeria i microbiologia) que a mesura que el treball avançava s’han integrat progressivament l’un amb l’altre. Dins del bloc de la microbiologia, el primer objectiu va ser l’estudi i l’anàlisi de les evidencies de la ruta sintròfica oxidadora d’acetat acoblada a la metanogenesis hidrogenotrofica, estudiant les interaccions entre aquestes dues grans comunitats. Es van quantificar mitjançant anàlisis de qPCR els dos grups majoritaris bastant-nos en els gens de referencia, 16SrRNA per bacteris i mcrA per arquees metanogèniques combinat amb un estudi de marcatge isotòpic. Complementàriament, el ràpid avenç de les tecnologies moleculars d’alt impacte com la seqüenciació shotgun i les eines bioinformàtiques, han permès desenvolupar estudis centrats en el genoma i poder generar bases de dades més accessibles i amplies relacionades amb la complexitat del microbioma ambiental. En segon lloc, un dels principals objectius del segon bloc era mitjançant els correctes paràmetres d’operació dels reactors aconseguir l’aparició i estabilitat de les sintròfies comentades anteriorment. Va ser fonamental també, establir protocols i marcar els paràmetres relacionals amb la configuració dels reactors, per aquest motiu, es va basar el disseny d’aquests digestors en els resultats obtinguts dels experiments discontinus previs. Seguint en aquesta línia, es van analitzar minuciosament paràmetres com el temps de retenció hidràulic, velocitat de càrrega orgànica, rangs de temperatura i configuració del reactor. Finalment, un dels punts crítics pel bon funcionament del projecte va ser l’elecció i disseny dels reactors. Es coneix, que el disseny i l’operació dels digestors es de vital importància per un desenvolupament òptim dels procés, per això es van provar diferents configuracions. La digestion anaerobia (DA) consiste en una cascada de interacciones sintróficas entre diferentes grupos de microganismos que tiene como principal finalidad la degradación de la materia orgánica con el fin de obtener biogás, una mezcla de CH4 y CO2 que puede ser de gran valor en el campo de las energíaas renovables. El proceso de DA ha sido diseñado para una amplia gama de aplicaciones y para obtener un mayor rendimiento de biogás. Sin embargo, el proceso de DA podría verse obstaculizado por el efecto inhibidor de los ácidos grasos de cadena larga, el amoníaco de la hidrólisis de proteínas o los compuestos sulfurados. El objetivo principal de esta tesis es desarrollar técnicas y métodos innovadores para degradar las proteínas. Como se describe a lo largo de las siguientes secciones, estos compuestos son potecialmente inhibidores del proceso de DA y, en consecuencia, de la producción de CH4. Este tipo de residuo con alta carga de proteínas emite altas concentraciones de NH3 cuando éstas son degradadas. Está reportado que bajo estas condiciones desfavorables el principal grupo de microorganismos productores de CH4 (arqueas metanogénicas) se encuentra total o parcialmente inhibido. Sin embargo, dentro de esta gran comunidad de arqueas capaces de producir CH4, existen algunos reductos capaces de mantenerse activas bajo concentraciones de elevado nitrógeno amoniacal mediante la ruta de la metanogenesis hidrogenotrófica. Esta población abre nuevas posibilidades para obtención de biogás de este tipo de residuos. Una de estas opciones consiste en incrementar las poblaciones oxidadoras de acetato para lograr una relación sintrófica estable con estas poblacions hidrogenotrófcas, evitando de este la inhibición causada por NH3. Además, en muchas ocasiones este tipo de residuos con alta carga proteíca van asociados a una elevada concentración de compuestos sulfurados, lo que podría conllevar una reducción de éstos a ácido sulfhídrico (H2S). Esta molécula es tóxica, corrosiva y olorosa, que provoca varios problemas en DA y en las instalaciones asociadas. La reacción biológica que conlleva a la formación de este compuesto está mediada por el grupo de bacterias conocidas como bacterias sulfato reductoras (SRB). Estas comunidades microbianas, SRB, tienen la capacidad de acoplar la oxidación de la materia orgánica a la reducción del SO42- compitiendo directamente por los sustratos comunes con las arqueas productoras de CH4 y bacterias homoacetogénicas inhibiendo de este modo, la producción de biogás. Se han llevado a cabo dos grandes bloques (ingeniería y microbiología) que a medida que se avanzaba con el trabajo han ido integrándose. En primer lugar, se llevaron a cabo diferentes estudios en régimen discontinuo a escala laboratorio, monitorizando los parámetros físicoquimicos y la evolución de las comunidades microbianas. El primer objetivo fue el estudio y análisis de las evidencias de la ruta sintrófica oxidadora de acetato acoplada a una metanogenesis hidrogenotrófica, estudiando las interacciones entre estas dos comunidades. Para ello, se cuantificaron mediante qPCR los dos grupos mayoritarios basándonos en los genes de referencia, 16SrRNA para la monitorización de las bacterias, y mcrA en el caso de las arqueas metanogénicas combinando esta cuantificación con el marcaje de compuestos isotópicos. Además, se ha podido desarrollar estudios centrados en el estudio del genoma gracias a la secuanciación shotgun y las herramientas bionformáticas. En segundo lugar, uno de los principales era mediante los correctos parámetros de operación de los reactores conseguir la aparición y estabilidad de las sintrofías comentadas anteriormente. Fue fundamental establecer protocolos y marcar los parámetros relacionados con la configuración de los reactores, y para ello se basó el diseño de estos en los resultados obtenidos de los diferentes ensayos discontinuos previos. Siguiendo en esta línea, se analizaron meticulosamente parámetros como tiempo de retención hidráulico, velocidad de carga orgánica, rangos de temperatura y configuración del reactor. Finalmente, uno de los puntos críticos fue la elección y diseño de los reactores. Es bien sabido, que el diseño y operación del digestor es crucial para un desarrollo óptimo del proceso, por ello se probaron diferentes configuraciones

BACKGROUND: Exposure to trihalomethanes (THMs) in drinking water has consistently been associated with an increased risk of bladder cancer, but evidence on other cancers including the breast is very limited. OBJECTIVES: We assessed long-term exposure to THMs to evaluate the association with female breast cancer (BC) risk. METHODS: A multi case-control study was conducted in Spain from 2008 to 2013. We included 1003 incident BC cases (women 20-85years old) recruited from 14 hospitals and 1458 population controls. Subjects were interviewed to ascertain residential histories and major recognized risk factors for BC. Mean residential levels of chloroform, brominated THMs (Br-THMs) and the sum of both as total THM (TTHMs) during the adult-lifetime were calculated. RESULTS: Mean adult-lifetime residential levels ranged from 0.8 to 145.7μg/L for TTHM (median=30.8), from 0.2 to 62.4μg/L for chloroform (median=19.7) and from 0.3 to 126.0μg/L for Br-THMs (median=9.7). Adult-lifetime residential chloroform was associated with BC (adjusted OR=1.47; 95%CI=1.05, 2.06 for the highest (>24μg/L) vs. lowest (31μg/L vs. 48μg/L vs.

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2017, Tutors: Alan C. Spivey, Fèlix Urpí, Phosphorothioate oligonucleotides have been deeply studied as antisense therapy drugs. Their stereoselective synthesis, however, still depends on the use of chiral auxiliaries or modifications on the individual nucleosides, which slow their synthesis and increase costs. A catalytic asymmetric synthesis of these oligonucleotides would therefore be of great interest. Herein the catalytic asymmetric synthesis of dinucleoside phosphorothioates is attempted. After failing to optimise the conditions for the coupling using 4-DMAP-N-oxides as nucleophilic catalysts, hydrogen bond donors were envisaged as potential catalysts. Through the use of bifunctional thioureas containing a tethered amine, adequate conditions for the coupling were found and diastereoselectivity could be measured. Although low conversions were obtained, moderate selectivities were achieved for the synthesis of these dinucleosides

Aldol reactions of titanium enolates of lactate-derived ethyl ketone 1 with other ketones proceed in a very efficient and stereocontrolled manner provided that a further equivalent of TiCl4 is added to the reacting mixture. The scope of these reactions encompasses simple ketones such as acetone or cyclohexanone as well as other ketones that contain potential chelating groups such as pyruvate esters or α- and β-hydroxy ketones.

[EN] Five new tetraphenylethylene (TPE) derivatives were synthesised and their aggregation-induced emission (AIE) was evaluated in mixtures of THF/water and MeOH/water. The influence of regiochemistry and length of the chains in the substituents on emissive properties was studied., We thank the Spanish Government, FEDER funds (MAT2015-64139- C4-1-R and MAT2015-64139-C4-4-R) and the Generalitat Valenciana (PROMETEOII/2014/047) for support.

The potential for rivers to alter the flux of dissolved organic matter (DOM) from land to ocean is widely accepted. Yet anticipating when and where rivers behave as active reactors vs. passive pipes of DOM stands as a major knowledge gap in river biogeochemistry, resulting in uncertainties for global carbon models. Here, we investigate the controls on in‐stream DOM dynamics by evaluating changes in DOM concentration and composition along several reaches of a medium‐sized river network over one full hydrological year. Roughly half of the observations over time and space showed active reactor conditions and, among these, similar proportion of gains and losses was measured. High water residence times promoted the active over passive behavior of the reaches, while DOM properties and nitrate availability determined whether they supplied or removed DOM from the river. Among different DOM fractions, protein‐like DOM both of terrestrial and aquatic origin seemed to drive bulk DOM patterns. Our study emphasizes the role of water residence time as a physical constraint for in‐stream processes, and provides new insights into the key factors governing the net balance between in‐stream gains and losses of DOM in rivers This research was funded by the Spanish Ministry of Economy and Competitiveness through the projects REMEDIATION (CGL2014-57215-C4-2-R) and FUNSTREAM (CGL2014-58760-C3-3-R). J. P. Casas-Ruiz and Ll. Gómez-Gener were supported by FPI predoctoral grants (BES-2012-059655 and BES-2012-059743), and N. Catal an held a Wenner-Gren foundation stipend (2014–2016; Sweden). This work profited from the research network NETLAKE COST Action (ES1201), supported by COST (European Cooperation in Science and Technology). Authors also acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Group (2014 SGR 291)— Catalan Institute for Water Research

Artificial recharge of aquifers through infiltration basins (AR) improves water quality and in- creases groundwater resources, which make of it an appropriate technique for the renaturalization of waters affected directly or indirectly by wastewater effluents. Emerging organic compounds (EOCs), typically present in such waters, are mainly reduced during AR by sorption and biotrans- formation. We installed a reactive barrier in an infiltration basin (5000 m2) to enhance the removal of EOCs in the recharge water. The barrier consisted of sand, vegetable compost, iron oxide and clay. Vegetable compost was aimed at: 1) release organic carbon to be used as a carbon source by the microbial community thus promoting the generation of diverse redox conditions, and 2) to adsorb neutral EOCs. Clay and iron oxides were aimed at increasing sorption sites for cationic and anionic EOCs, respectively. Field application of such a design was tested by comparing the redox indicators and behavior of EOCs prior and after the installation of the reactive barrier. Residence time distributions of the recharge water at the monitoring points were obtained by a pulse tracer test. These distributions were used for calibrating a conservative transport and flow model of the aquifer. Finally, first order rates and retardation factors of several EOCs were estimated by fitting model outputs to observed concentrations. The estimation of the first order decay rates and retardation factors of several EOCs allowed the comparison of such values with values reported from other field sites and column experiments. The reactive barrier succeed in releasing organic carbon and achieving diverse redox condi- tions. The transformation of most EOCs was enhanced after the installation of the reactive barrier. In fact, first order rates and retardation factors were higher in the reactive barrier than in the rest of the aquifer and similar or higher than those from literature. In summary, addition of proposed reactive barrier significantly enhanced the performance of artificial recharge via infiltration basins, thus contributing to the renaturalization of recharged waters., La recarga artificial de acuíferos a través de balsas de infiltración (AR) mejora la calidad del agua y aumenta recursos de aguas subterráneas, convirtiéndola en una técnica apropiada para la renaturalización de las aguas afectadas directa o indirectamente por los efluentes de aguas residuales. En este tipo de aguas la presencia de compuestos orgánicos emergentes (EOCs) es más que frecuente. Durante la recarga artificial este tipo de compuestos es eliminado principalmente debido a la adsorción y a la biotransformación. Para mejorar la eliminación de los EOCs durante la infiltración del agua de recarga se instaló una barrera reactiva en una balsa de infiltración. La barrera consistía en arena, compost vegetal, óxidos de hierro y arcilla. La finalidad del compost vegetal era por un lado la de aportar carbono orgánico disuelto para ser utilizado como principal fuente de carbono por la comunidad microbiana promoviendo así la generación de diversas condiciones redox, y por otro lado la de adsorber EOCs neutros. La Arcilla y los óxidos de hierro se pusieron con la intención de aumentar los sitios de adsorción para los EOCs catiónicos y aniónicos, respectivamente. La efectividad de la barrera en el campo se estudió comparando el comportamiento de los indicadores redox y de los EOCs antes y después de la instalación de la barrera. Mediante un ensayo de trazadores tipo pulso se obtuvieron las distribuciones de los tiempos de residencia del agua de recarga a los puntos de observación. Estas distribuciones se utilizaron para calibrar un modelo de flujo y transporte conservativo del acuífero. Por último, las tasas de degradación de primer orden y los factores de retardo de varios EOCs se estimaron mediante el ajuste de los resultados del modelo con las concentraciones observadas. Las tasas de degradación y los factores de retardo estimados se compararon con valores encontrados en la bibliografía. La barrera reactiva cumple su función aportando carbono orgánico y generando diversas condiciones redox. Muchos de los EOCs estudiados mostraron una mejor transformación cuando la recarga se realizó con la barrera reactiva. Las tasas de degradación y factores de retardo estimados en la barrera son mayores que los estimados para el resto del acuífero, y del mismo orden o superiores a los encontrados en la bibliografía. En resumen, la barrera reactiva propuesta mejora significativamente el rendimiento de la recarga artificial a través de balsas de infiltración, contribuyendo así a la renaturalización de las aguas recargadas

Here we review recent developments in analytical proposals for the assessment of inorganic arsenic (iAs) content in food products. Interest in the determination of iAs in products for human consumption such as food commodities, wine, and seaweed among others is fueled by the wide recognition of its toxic effects on humans, even at low concentrations. Currently, the need for robust and reliable analytical methods is recognized by various international safety and health agencies, and by organizations in charge of establishing acceptable tolerance levels of iAs in food. This review summarizes the state of the art of analytical methods while highlighting tools for the assessment of quality assessment of the results, such as the production and evaluation of certified reference materials (CRMs) and the availability of specific proficiency testing (PT) programmes. Because the number of studies dedicated to the subject of this review has increased considerably over recent years, the sources consulted and cited here are limited to those from 2010 to the end of 2015.