Connecting the chemical and biological reactivity of epoxides

The chemical reactivity of the mutagenic epoxides (EP) propylene oxide (PO), 1,2-epoxybutane (1,2-EB), and cis- and trans-2,3-epoxybutane (cis- and trans-2,3-EB) with 4-(p-nitrobenzyl)pyridine (NBP), a bionucleophile model for S(N)2 alkylating agents with high affinity for the guanine-N7 position, was investigated kinetically. It was found that three reactions are involved simultaneously: the alkylation reaction of NBP by EP, which yields the corresponding NBP-EP adducts through an S(N)2 mechanism, and EP and NBP-EP hydrolysis reactions. PO and 1,2-EB were seen to exhibit a higher alkylating potential than cis- and trans-2,3-EB. From a study of the correlations between the chemical reactivity (kinetic parameters) and the biological effectiveness of oxiranes, the following conclusions can be drawn: (i) the hydrolysis reactions of epoxides must be taken into account to understand their bioactivity. (ii) The fraction (f) of the alkylating oxirane that forms the adduct and the adduct life (AL) permit the potential of epoxides as bioactive molecules to be rationalized even semiquantitatively; and (iii) alkylation of DNA by epoxides and the O-6-/N7-guanine adduct ratio are directly related to their mutagenicity in vitro.Publicad

New amphiphilic semi-interpenetrating networks based on polysulfone for anion-exchange membrane fuel cells with improved alkaline and mechanical stabilities

As considerable advance has recently been made in enhancing the conductivity of anion-exchange membranes, durability has become the critical requirement in the development of fuel cells. Such properties often develop at the expense of the other. In this work, new amphiphilic semi-interpenetrating networks composed of free polysulfone and crosslinked polysulfone are synthesized for the first time. The same nature of both polymers makes them highly compatible. The free polymer provides the hydrophobic component, whereas the crosslinked polysulfone, functionalized with trimethylammonium, 1-methylimidazolium, or 1,2-dimethylimidazolium groups, is responsible for the ionic conductivity. The compatibility between both components in the blend, improves the mechanical properties, while unaffecting the transport properties. Thus, the obtained membranes exceed the mechanical behaviour of commercial materials, even in conditions of extreme humidity and temperature. The tensile strength of these synthesized membranes can reach to relatively high values, and when compared to the commercial PSU, the difference in tensile strength can be noted to be as low as 10%. Moreover, the tensile strength and the ductility values of the crosslinked PSU are higher than those obtained with non-crosslinked PSU. Furthermore, the membranes presented in this work show a great alkaline stability (e.g. semi-interpenetrating network containing 1,2-dimethylimidazolium maintains 87% of the ionic conductivity after 14 days of treatment). Thus, these membranes provide an improvement in the durability limiting factors, in comparison to functionalized polysulfones, fulfilling the requirements to be used as electrolytes in anion-exchange membrane fuel cells.We thank Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER/UE) for funding the project MINECO (MAT2016-78632-C4-3-R, and PID-2019-106662RB-C43) which supported this work. We also wish to thank the project from the Regional Government (Comunidad de Madrid through PEM4ENERGY-CM-UC3M)

Synthesis and characterization of novel anion exchange membranes based on semi-interpenetrating networks of functionalized polysulfone: Effect of ionic crosslinking

This article belongs to the Special Issue Polymeric Membranes for Advanced Applications.In this work, anion exchange membranes based on polymer semi-interpenetrating networks were synthesized and characterized for the first time. The networks are composed of sulfonated polysulfone and 1-methylimidazolium-functionalized polysulfone crosslinked covalently with N,N,N′,N′-tetramethylethylenediamine (degree of crosslinking of 5%). In these membranes, sulfonic groups interact electrostatically with cationic groups to form an ionic crosslinking structure with improved alkaline stability. The effect of the ionic crosslinking on the thermal, chemical, mechanical, and electrochemical behavior of membranes was studied. These crosslinked membranes containing sulfonated polysulfone showed higher thermal stability, with a delay of around 20 °C in the onset decomposition temperature value of the functional groups than the crosslinked membranes containing free polysulfone. The tensile strength values were maintained above 44 MPa in all membranes with a degree of chloromethylation (DC) below 100%. The maximum ionic conductivity value is reached with the membrane with the highest degree of chloromethylation. The chemical stability in alkaline medium of the conducting membranes also improved. Thus, the ionic conductivity variation of the membranes after 96 h in a 1 M potassium hydroxide (KOH) solution is less pronounced when polysulfone is replaced by sulfonated polysulfone. So, the ionic crosslinking which joins both components of the blends together, improves the material’s properties making progress in the development of new solid electrolyte for polymeric fuel cells.This work was funded by Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER/UE), PID-2019-106662RB-C43, by the Spanish Government, MAT2016-78632-C4-3-R, and by the Regional Government PEM4ENERGY-CM-UC3M funded by the call "Programa de apoyo a la realización de proyectos interdisciplinares de I+D para jóvenes investigadores de la Universidad Carlos III de Madrid 2019-2020" under the frame of the "Convenio Plurianual Comunidad de Madrid-Universidad Carlos III de Madrid"

Using Metal-Organic Framework HKUST-1 for the Preparation of High-Conductive Hybrid Membranes Based on Multiblock Copolymers for Fuel Cells

Novel proton-conducting hybrid membranes consisting of sulfonated multiblock copolymer of polysulfone and polyphenylsulfone (SPES) reinforced with a HKUST-1 metal-organic framework (MOF) (5, 10, and 20 wt. %) were prepared and characterized for fuel cell applications. The presence of the MOF in the copolymer was confirmed by means of FE-SEM and EDS. The hybrid membranes show a lower contact angle value than the pure SPES, in agreement with the water uptake (WU%), i.e., by adding 5 wt. % of the MOF, this parameter increases by 20% and 40% at 30 °C and 60 °C, respectively. Additionally, the presence of the MOF increases the ion exchange capacity (IEC) from 1.62 to 1.93 mequivH+ g−1. Thermogravimetric analysis reveals that the hybrid membranes demonstrate high thermal stability in the fuel cell operation temperature range ( 85 MPa in the Na+ form). Proton conductivity was analyzed using EIS, achieving the highest value with a 5 wt. % load of the HKUST-1. This value is lower than that observed for the HKUST-1/Nafion system. However, polarization and power density curves show a remarkably better performance of the hybrid membranes in comparison to both the pure SPES and the pure Nafion membranesThis work was funded by the Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER/UE), PID-2019-106662RB-C43, by the Spanish Government, MAT2016-78632-C4-3-R, by the Regional Government PEM4ENERGY-CM-UC3M funded by the call “Programa de apoyo a la realización de proyectos interdisciplinares de I + D para jóvenes investigadores de la Universidad Carlos III de Madrid 2019–2020” under the frame of the “Con-venio Plurianual Comunidad de Madrid-Universidad Carlos III de Madrid”, and by the Ministry of Science and Higher Education of the Russian Federation (State assignment in the field of scientific activity, № 0852-2020-0019). The authors would like to thank the following institutions for funding the projects: the Agencia Española de Investigación/Fondo Europeo de Desarrollo Regional (FEDER/UE): Projects PID2019-106662RBC43 and MAT2016-78362-C4-3-R, and the Comunidad de Madrid: Projects “Excelencia para el Profesorado Universitario”—(EPUC3M04) and PEM4ENERGY-CM-UC3

Sulfonated Polysulfone/TiO2(B) Nanowires Composite Membranes as Polymer Electrolytes in Fuel Cells

New proton conducting membranes based on sulfonated polysulfone (sPSU) reinforced with TiO2 (B) nanowires (1, 2, 5 and 10 wt.%) were synthesized and characterized. TiO2 (B) nanowires were synthesized by means of a hydrothermal method by mixing TiO2 precursor in aqueous solution of NaOH as solvent. The presence of the TiO2 (B) nanowires into the polymer were confirmed by means of Field Emission Scanning Electron Microscopy, Fourier transform infrared and X-ray diffraction. The thermal study showed an increase of almost 20 ◦C in the maximum temperature of sPSU backbone decomposition due to the presence of 10 wt.% TiO2 (B) nanowires. Water uptake also is improved with the presence of hydrophilic TiO2 (B) nanowires. Proton conductivity of sPSU with 10 wt.% TiO2 (B) nanowires was 21 mS cm−1 (at 85 ◦C and 100% RH). Under these experimental conditions the power density was 350 mW cm−2 similar to the value obtained for Nafion 117. Considering all these obtained results, the composite membrane doped with 10 wt.% TiO2 (B) nanowires is a promising candidate as proton exchange electrolyte in fuel cells (PEMFCs), especially those operating at high temperatures.The authors would like to thank the following Institution for funding the Projects: Agencia Española de Investigación /Fondo Europeo de Desarrollo Regional (FEDER/UE): Projects PID2019-106662RBC43 and MAT2016-78362-C4-3-R. Comunidad de Madrid: Projects "Excelencia para el Profesorado Universitario"—EPUC3M04) and PEM4ENERGY-CM-UC3M

Characterization and Modeling of Free Volume and Ionic Conduction in Multiblock Copolymer Proton Exchange Membranes

Free volume plays a key role on transport in proton exchange membranes (PEMs), including ionic conduction, species permeation, and diffusion. Positron annihilation lifetime spectroscopy and electrochemical impedance spectroscopy are used to characterize the pore size distribution and ionic conductivity of synthesized PEMs from polysulfone/polyphenylsulfone multiblock copolymers with different degrees of sulfonation (SPES). The experimental data are combined with a bundle-of-tubes model at the cluster-network scale to examine water uptake and proton conduction. The results show that the free pore size changes little with temperature in agreement with the good thermo-mechanical properties of SPES. However, the free volume is significantly lower than that of Nafion®, leading to lower ionic conductivity. This is explained by the reduction of the bulk space available for proton transfer where the activation free energy is lower, as well as an increase in the tortuosity of the ionic network.This research was funded by the Spanish Agencia Estatal de Investigación (PID2019- 106740RB-I00) and the Community of Madrid (PEM4ENERGY-CM-UC3M) by the call “Programa de apoyo a la realización de proyectos interdisciplinares de I + D para jóvenes investigadores de la Universidad Carlos III de Madrid 2019–2020” under the frame of the “Convenio Plurianual Comunidad de Madrid-Universidad Carlos III de Madrid”

Prognostic value of bioelectrical impedance analysis in head and neck cancer patients undergoing radiotherapy: a VALOR® study

© 2024 Prior-Sánchez, Herrera-Martínez, Zarco-Martín, Fernández-Jiménez, Gonzalo-Marín, Muñoz-Garach, Vilchez-López, Cayón-Blanco, Villarubia-Pozo, Muñoz-Jiménez, Zarco-Rodríguez, Rabat-Restrepo, Luengo-Pérez, Boughanem, Martínez-Ramírez and García-Almeida. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Introduction: Bioelectrical impedance analysis (BIA) serves as a method to estimate body composition. Parameters such as phase angle (PA), standardized phase angle (SPA), body mass cell (BCM), BCM index (BCMI), and fat-free mass (FFM) might significantly impact the prognosis of head and neck cancer (HNC) patients. The present study aimed to investigate whether bioelectrical parameters can be used to predict survival in the HNC population and establish the optimal cutoff points for predictive accuracy. Methods: A multicenter observational study was performed across 12 tertiary hospitals in Andalusia (a region from the south of Spain). A total of 494 patients diagnosed with HNC between 2020 and 2022 at different stages were included in this study, with a minimum follow-up period of 12 months. The BIA assessment was carried out during the first 2 weeks of radical radiotherapy treatment with chemotherapy or other systemic treatments. A multivariate logistic regression analysis of overall survival, complications, hospital admission, and palliative care and its relationship with BIA nutritional assessment was performed. Results: Significant prognostic factors identified in the multivariable analysis encompassed phase angle (PA), standardized phase angle (SPA), body cell mass (BCM), and BCM index (BCMI). Lower PA and BCM values were significantly associated with adverse clinical outcomes. A BCM threshold above 17 kg/m2 was the most significant predictor for predicting survival within the overall HNC population. The PA values of <5.1° in male and <4.8° in female patients showed the best predictive potential for mortality. Increased PA (as a continuous variable) demonstrated a significantly reduced risk for mortality (OR, 0.64; 95% CI, 0.43–0.94; p < 0.05) and a decreased likelihood of hospital admission (OR, 0.75; 95% CI, 0.52–1.07; p < 0.05). Higher BCM correlated with a lower risk of mortality (OR, 0.88; 95% CI, 0.80–0.96; p < 0.01) and a diminished probability of hospital admission (OR, 0.91; 95% CI, 0.83–0.99; p < 0.05). Conclusion: BIA is a crucial tool in the nutritional assessment of HNC patients. BCM and PA are the main bioelectrical parameters used to predict clinical outcomes in this population. Future studies are needed to validate BIA variables in a large cohort to ensure whether early intensification of nutritional treatment would improve survival.This research was funded by FRESENEIUS KABI. The APC was funded by FRESENIUS KABI.Peer reviewe

Prognostic value of bioelectrical impedance analysis in head and neck cancer patients undergoing radiotherapy: a VALOR® study

IntroductionBioelectrical impedance analysis (BIA) serves as a method to estimate body composition. Parameters such as phase angle (PA), standardized phase angle (SPA), body mass cell (BCM), BCM index (BCMI), and fat-free mass (FFM) might significantly impact the prognosis of head and neck cancer (HNC) patients. The present study aimed to investigate whether bioelectrical parameters can be used to predict survival in the HNC population and establish the optimal cutoff points for predictive accuracy.MethodsA multicenter observational study was performed across 12 tertiary hospitals in Andalusia (a region from the south of Spain). A total of 494 patients diagnosed with HNC between 2020 and 2022 at different stages were included in this study, with a minimum follow-up period of 12 months. The BIA assessment was carried out during the first 2 weeks of radical radiotherapy treatment with chemotherapy or other systemic treatments. A multivariate logistic regression analysis of overall survival, complications, hospital admission, and palliative care and its relationship with BIA nutritional assessment was performed.ResultsSignificant prognostic factors identified in the multivariable analysis encompassed phase angle (PA), standardized phase angle (SPA), body cell mass (BCM), and BCM index (BCMI). Lower PA and BCM values were significantly associated with adverse clinical outcomes. A BCM threshold above 17 kg/m2 was the most significant predictor for predicting survival within the overall HNC population. The PA values of &lt;5.1° in male and &lt;4.8° in female patients showed the best predictive potential for mortality. Increased PA (as a continuous variable) demonstrated a significantly reduced risk for mortality (OR, 0.64; 95% CI, 0.43–0.94; p &lt; 0.05) and a decreased likelihood of hospital admission (OR, 0.75; 95% CI, 0.52–1.07; p &lt; 0.05). Higher BCM correlated with a lower risk of mortality (OR, 0.88; 95% CI, 0.80–0.96; p &lt; 0.01) and a diminished probability of hospital admission (OR, 0.91; 95% CI, 0.83–0.99; p &lt; 0.05).ConclusionBIA is a crucial tool in the nutritional assessment of HNC patients. BCM and PA are the main bioelectrical parameters used to predict clinical outcomes in this population. Future studies are needed to validate BIA variables in a large cohort to ensure whether early intensification of nutritional treatment would improve survival

Jardins per a la salut

Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia. Assignatura: Botànica farmacèutica. Curs: 2014-2015. Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són el recull de les fitxes botàniques de 128 espècies presents en el Jardí Ferran Soldevila de l’Edifici Històric de la UB. Els treballs han estat realitzats manera individual per part dels estudiants dels grups M-3 i T-1 de l’assignatura Botànica Farmacèutica durant els mesos de febrer a maig del curs 2014-15 com a resultat final del Projecte d’Innovació Docent «Jardins per a la salut: aprenentatge servei a Botànica farmacèutica» (codi 2014PID-UB/054). Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pels professors de l’assignatura. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica. També s’ha pretès motivar els estudiants a través del retorn de part del seu esforç a la societat a través d’una experiència d’Aprenentatge-Servei, deixant disponible finalment el treball dels estudiants per a poder ser consultable a través d’una Web pública amb la possibilitat de poder-ho fer in-situ en el propi jardí mitjançant codis QR amb un smartphone

Estudio cinético del potencial alquilante del ácido sórbico y de los productos de su reacción con nitrito

[ES] La aparición de tumores en ratas tratadas con nitrosodimetilamina en la investigación pionera de Magee y Barnes abrió un amplio horizonte al estudio de los mecanismos de formación de nitrosocompuestos y de sus efectos biológicos. Los nitrosocompuestos sse pueden formar en alimentos con nitrito como conservante, en el medio ambiente y en el tracto digestivo, especialmente en el estomago. Algunos N-nitrosocompuestos son sintetizados por las plantas aunque muchos se forman eventualmente como consecuencia de la nitrosación de aminas. En 1967 Druckery y colaboradores observaron que las nitrosaminas sufren in vivo una reacción de α-hidroxilación cuyo producto, el hidroxicompuesto correspondiente, se fragmenta espontáneamente para dar lugar a un agente alquilante, el ión alquildiazonio, que actúa en sitios específicos del ADN celular, iniciándose así el proceso de carcinogénesis. El proceso de hidroxilación no tiene lugar in vitro, siendo onecesaria la activación enzimática. Con objeto de profundizar en el conocimiento de los mecanismos de alquilación, en la primera parte del trabajo descrito en esta memoria se ha estudiado la capacidad alquilante del ácido sórbico y sus sales sódica y potásica.[EN] The appearance of tumors in rates treated with nitrosodimetilamina in the pioneering investigation of Magee and Barnes opened a wide horizon for the study of the mechanisms of formation of nitrosocompuestos and of his biological effects. The nitrosocompuestos sse can form in food with nitrite as preservingly, in the environment and in the digestive tract, specially in the stomach. Some N-nitrosocompuestos are synthesized by the plants though many are formed eventually as consequence of the nitrosación of aminas. In 1967 Druckery and collaborators they observed that the nitrosaminas suffer in I live through a reaction of to - hidroxilación whose product, the corresponding hidroxicompuesto, fragments spontaneously to give place to an agent alquilante, the ión alquildiazonio, which acts in specific sites of the cellular DNA, beginning this way the process of carcinogénesis. The process of hidroxilación does not take place in vitro, being onecesaria the enzymatical activation. In order to penetrate into the knowledge of the mechanisms of alquilación, in the first part of the work described in this memory the capacity has been studied alquilante of the acid sórbico and his you work out sodium and potassium