Organic Anolytes Design and Membrane Modification Through Efficient Redox Flow Batteries

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química Orgánica. Fecha de Lectura: 31-10-2023El presente trabajo ha sido financiado por la Comunidad Europea mediante el Proyecto de investigación HIGREEW, Affordable High High- performance Green Redox Flow Batteries. Grant agreement 875613. H2020: LC LC- BATBAT-4-201

Microstructural description of ion exchange membranes: The effect of PPy-based modification

Properties of ion exchange membranes (IEMs) both cationic and anionic were widely analysed before and after chemical. The modification aims to reduce the crossover phenomena typically observed in RFBs by incorporating polypyrrole (PPy) at the inner of commercial IEMs. In this work, we have explored the insight of membranes by structural and generalized conductivity considerations and its implications in terms of physicochemical characteristics. Transport Structural Parameters (TSP) have been obtained from the electrolyte concentration dependencies (NaCl, in this work). AEMs successfully increased their specific conductivity (between 2.5 and 3.9 times) whereas CEMs slightly decreased (between 1.3 and 2 times). This approach was useful for the description of membrane electro-transport by using the so-called two-phase model which considers an IEM as an heterophase system (particularly, gel and interstitial phase) and their arrangement. AEMs almost doubled increased whereas CEMs doubled decreased their internal microphase arrangement in terms of structural parameter (α). A modification of the established model was applied to the CEMs to better understand their specific behaviour after polymerization. Up to 3.5 times the diffusion coefficient was obtained in AEMs after PPy modification. Finally, based on TSP obtained we propose a microstructural description for the IEMs studied in this workThis work has been funded by the European Union under the HIGREEW project, Affordable High-performance Green Redox Flow batteries (Grant agreement no. 875613) H2020: LC-BAT-4-2019, by the Spanish Ministry of Economy PID 2020-116712RBC21 and Madrid Regional Research Council (CAM) grant. n. P2018/EMT-4344 BIOTRESC

Sulfonate-Based Triazine Multiple-Electron Anolyte for Aqueous Organic Flow Batteries

A new highly soluble triazine derivative (SPr)34TpyTz showing three reversible redox processes with fast kinetics and high diffusion coefficients has been synthesized using an efficient, low-cost, and straightforward synthetic route. Concentrated single cell tests and DFT studies reveal a tendency of the reduced triazine species to form aggregates which could be avoided by tuning the supporting electrolyte concentration. Under the right conditions, (SPr)34TpyTz shows no capacity decay and good Coulombic, voltage, and energy efficiencies for the storage of two electrons. The storage of further electrons leads to a higher capacity decay and an increase of the electrolyte pH, suggesting the irreversible protonation of the generated species. So, a plausible mechanism has been proposed. A higher concentration of (SPr)34TpyTz shows slightly higher capacity decay and lower efficiencies due to the aggregate formationThis research was funded by the European Union under the HIGREEW project, Affordable High-performance Green Redox Flow batteries. Grant agreement 875613. H2020: LC-BAT-4-2019. P.P. acknowledges funding from the European Research Council through a Starting grant (agreement no. 950038) and the Academy Research Fellow funding and project funding by the Academy of Finland (grants nos. 315739, 334828, and 343493

DFT calculation, a practical tool to predict the electrochemical behaviour of organic electrolytes in aqueous redox flow batteries

Herein, a computational predictive tool for redox flow batteries based on NBO and ADCH charge distribution studies is presented and supported by experimental evidence. Using highly water soluble (>2 M) non-planar 2,2′ - bipyridinium salts as a case of study, this work presents a DFT protocol that successfully predicts the stability and forecasts their potential application as active materials for Aqueous Organic Redox Flow Batteries (AORFB). An initial theoretical-experimental characterization of selected bipyridines served to determine the effect of the ring size, geometry, and electron density on the physico-chemical properties of the materials. Nonetheless, the NBO and ADCH charge analyses were essential tools to understand the stability of the reduced species in terms of electronic delocalization and the importance of the molecular design on the stability of electrolyte for AORFB. Based on these results, the cell performance of seven-membered 2,2′ -bypiridinium salt, (2), and m-Me substituted homologous, (4), were compared. The significantly lower capacity decay rendered by compound 4 based electrolyte, (0.35%/cycle) compared with compound 2 based electrolyte, (0.71%/cycle) was in good agreement with the predicted stability. The aim of this work is to highlight the powerful synergy between DFT calculations and organic chemistry in predicting the behaviour of different negolytesThis work has been funded by the European Union under the HIGREEW project, Affordable High-performance Green Redox Flow batteries (Grant agreement no. 875613). H2020: LC-BAT-4-2019. A.C. Lopes acknowledges the Ramon y Cajal (RYC2021-032277-I) research fellowship, the financial support from Ministerio de Ciencia e Innovacion ´ / AEI /10.13039/501100011033 and from European Union NextGenerationEU/PRTR. We also thank the CCC-UAM (Graforr project) for allocation of computer tim

Sensibilidad del test de valoración de la resistencia específica en el fútbol (TVREF) para evaluar la influencia del entrenamiento de pretemporada en la resistencia y capacidad aeróbica de futbolistas profesionales

El test TVREF ha sido utilizado en diferentes estudios científicos sobre valoración de la condición física en fútbol. Ninguno de ellos ha comprobado la sensibilidad de este test a los efectos del entrenamiento en fútbol, comparándolo con los resultados de un test continuo. 24 futbolistas de 1ª División participaron en el estudio, siendo evaluados al inicio y final de una pretemporada de entrenamiento mediante 2 tests de campo (TVREF y Course Navette) para valorar la velocidad aeróbica máxima (VAM) y otros parámetros de resistencia aeróbica (umbral anaeróbico interválico y capacidad de recuperación en el TVREF). La VAM mejoró 0.5 km/h en el TVREF (p<0.05), pero no en el Course Navette (0.1 km/h y p>0.05), a pesar de que el nivel de esfuerzo (frecuencia cardiaca máxima) fue similar en ambos tests. La velocidad en el umbral anaeróbico mejoró más que la VAM (0.9 km/h y p<0.001) en el TVREF. La frecuencia cardiaca para la misma velocidad de carrera disminuyó en ambos tests, pero de forma más significativa en el TVREF, lo que repercutió en una mejora de los porcentajes de recuperación cardiaca en los estadíos previos al umbral anaeróbico. En conclusión, el test TVREF es más sensible que el Course Navette para valorar los efectos del entrenamiento en fútbol, y ofrece más información que este último (umbral anaeróbico y capacidad de recuperación). Futuros trabajos deben comprobar si se puede estimar el VO2máx de los futbolistas al realizar este tes

Global disparities in surgeons’ workloads, academic engagement and rest periods: the on-calL shIft fOr geNEral SurgeonS (LIONESS) study

: The workload of general surgeons is multifaceted, encompassing not only surgical procedures but also a myriad of other responsibilities. From April to May 2023, we conducted a CHERRIES-compliant internet-based survey analyzing clinical practice, academic engagement, and post-on-call rest. The questionnaire featured six sections with 35 questions. Statistical analysis used Chi-square tests, ANOVA, and logistic regression (SPSS® v. 28). The survey received a total of 1.046 responses (65.4%). Over 78.0% of responders came from Europe, 65.1% came from a general surgery unit; 92.8% of European and 87.5% of North American respondents were involved in research, compared to 71.7% in Africa. Europe led in publishing research studies (6.6 ± 8.6 yearly). Teaching involvement was high in North America (100%) and Africa (91.7%). Surgeons reported an average of 6.7 ± 4.9 on-call shifts per month, with European and North American surgeons experiencing 6.5 ± 4.9 and 7.8 ± 4.1 on-calls monthly, respectively. African surgeons had the highest on-call frequency (8.7 ± 6.1). Post-on-call, only 35.1% of respondents received a day off. Europeans were most likely (40%) to have a day off, while African surgeons were least likely (6.7%). On the adjusted multivariable analysis HDI (Human Development Index) (aOR 1.993) hospital capacity &gt; 400 beds (aOR 2.423), working in a specialty surgery unit (aOR 2.087), and making the on-call in-house (aOR 5.446), significantly predicted the likelihood of having a day off after an on-call shift. Our study revealed critical insights into the disparities in workload, access to research, and professional opportunities for surgeons across different continents, underscored by the HDI

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

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

Understanding Aqueous Organic Redox Flow Batteries: A Guided Experimental Tour from Components Characterization to Final Assembly

The implementation of renewable energies into the electrical grid is one of our best options to mitigate the climate change. Redox flow batteries (RFB) are one of the most promising candidates for energy storage due to their scalability, durability and low cost. Despite this, just few studies have explained the basic concepts of RFBs and even fewer have reviewed the experimental conditions that are crucial for their development. This work aspired to be a helpful guide for beginner researchers who want to work in this exciting field. This guided tour aimed to clearly explain all the components and parameters of RFBs. Using a well-studied chemistry of anthraquinone (AQDS)-based anolyte and Na4[Fe(CN)6] catholyte, different techniques for the characterization of RFBs were described. The effects of some experimental parameters on battery performance such as electrolyte pH, O2 presence, membrane pretreatment and the capacity limiting side, were demonstrated. Furthermore, this analysis served to introduce different electrochemical techniques, i.e., load curve measurements, electrochemical impedance spectroscopy and charge–discharge cycling tests. This work aimed to be the nexus between the basic concepts and the first experimental steps in the RFB field merging theory and experimental data

Boron Dipyrromethene (BODIPY) as Electron-Withdrawing Group in Asymmetric Copper-Catalyzed [3+2] Cycloadditions for the Synthesis of Pyrrolidine-Based Biological Sensors

This is the peer reviewed version of the following article: Rigotti, T., Asenjo‐Pascual, J., Martín‐Somer, A., Milán Rois, P., Cordani, M., Díaz‐Tendero, S., ... & Alemán. Boron Dipyrromethene (BODIPY) as Electron‐Withdrawing Group in Asymmetric Copper‐Catalyzed [3+ 2] Cycloadditions for the Synthesis of Pyrrolidine‐Based Biological Sensors. Advanced Synthesis & Catalysis Volume 362, Issue 6, 17 March 2020, Pages 1345-1355 , which has been published in final form at https://doi.org/10.1002/adsc.201901465. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsIn this work, we describe the use of Boron Dipyrromethene (BODIPY) as electron-withdrawing group for activation of double bonds in asymmetric copper-catalyzed [3+2] cycloaddition reactions with azomethine ylides. The reactions take place under smooth conditions and with high enantiomeric excess for a large number of different substituents, pointing out the high activation of the alkene by using a boron dipyrromethene as electron-withdrawing group. Experimental, theoretical studies and comparison with other common electron-withdrawing groups in asymmetric copper-catalyzed [3+2] cycloadditions show the reasons of the different reactivity of the boron dipyrromethene derivatives, which can be exploited as a useful activating group in asymmetric catalysis. Additional experiments show that the so obtained pyrrolidines can be employed as biocompatible biosensors, which can be located in the endosomal compartments and do not present toxicity in three cell linesThis work was supported by the Spanish Government (RTI2018‐095038‐B‐I00, CTQ2016‐76061‐P, SAF2017‐87305‐R), Comunidad de Madrid (IND2017/IND‐7809), and co‐financed by European Structural and Investment Fund. We acknowledge the generous allocation of computing time at the CCC (UAM). Financial support from the Spanish Ministry of Economy and Competitiveness, through the ‘‘Maria de Maeztu’’ Program of Excellence in R&D (MDM‐2014‐0377), is also acknowledged. Asociación Española Contra el Cáncer, and IMDEA Nanociencia acknowledge support from the ′Severo Ochoa′ Programme for Centres of Excellence in R&D (MINECO, Grant SEV‐2016‐0686). P.M.R thanks the Ministry of Economy, Industry and competitiveness of Spain for the FPI grant (BES‐2017.082521). A.M.S. thanks CAM for a postdoctoral contract (2016‐T2/IND‐1660

BODIPY as electron withdrawing group for the activation of double bonds in asymmetric cycloaddition reactions

In this work we have found that a BODIPY can be used as an electron withdrawing group for the activation of double bonds in asymmetric catalysis. The synthesis of cyclohexyl derivatives containing a BODIPY unit can easily be achieved via trienamine catalysis. This allows a new different asymmetric synthesis of BODIPY derivatives and opens the door to future transformation of this useful fluorophore. In addition, the Quantum Chemistry calculations and mechanistic studies provide insights into the role of BODIPY as an EWGSpanish Government (CTQ2015-64561-R, CTQ2016-76061-P), CONACYT (project supported by the Fondo Sectorial de Investigación para la Educación) and PRODEP (Mexico) are acknowledged. We acknowledge allocation of computing time at the CCC-UAM. A. G. C. thanks MINECO (FPI) and T. J. P. CONACYT for PhD fellowships, respectively. A. M. S. thanks CAM for a postdoctoral contract (2016-T2/IND-1660). The authors wish to thank ''Comunidad de Madrid'' for its support to the FotoArt-CM Project (S2018/NMT-4367) through the Program of R&D activities between research groups in Technologies 2013, co-financed by European Structural Fund