The Acidity of a Carbon Nucleophile Dictates Enantioselectivity and Reactivity in Michael Additions to Aromatic and Aliphatic Enals via Iminium Activation

The Michael addition of activated methylenes to β-substituted α,β-unsaturated aldehydes (enals) via iminium catalysis takes place following reactivity and enantioselectivity patterns which depend on the electronic nature of the substituent in the β position (β-aryl or β-alkyl). Application of the same reaction conditions to both families of enals may result in erratic levels of asymmetric induction in the reactions of β-aryl enals or low reactivity with β-alkyl enals. A systematic analysis of this behavior using phenylacetic acid derivatives as case studies has led us to find a general trend: the different problems found for β-aryl and β-alkyl enals depend on the acidity of the nucleophile, and the outcome of the reaction for both types of enals can be improved substantially by careful choice of catalyst, solvent, and additive. Furthermore, this study has allowed us to understand subtle aspects of this transformation and has enabled the formulation of a general and reliable protocol to obtain high yields and enantioselectivities consistently, regardless of the acidity of the nucleophile and the nature of the substituent (aromatic or aliphatic) at the β positionWe thank CTQ-2009-12168, CAM (AVANCAT CS2009/PPQ-1634), UAM-CAM (CCG10-UAM/PPQ-5769), CTQ-2012-35957, CTQ2015-63997-C2-1-P, CTQ2016-78779-R and FOTOCARBON-CAM S2013/MIT-2841 for financial support. S.D. thanks the Comunidad Autónoma de Madrid (CAM), and E.R. and S.M. thank MICINN, for predoctoral fellowships. P.M. thanks MICINN for a Ramón y Cajal contract and the EU for a Marie Curie grant (CIG: HYPERCAT-30422

Thin-layer nanofiltration membranes using engineered biopolymers for seawater desalination pre-treatment processes

Nowadays water demand already exceeds supply and water scarcity is a global problem. So it is necessary to develop novel technologies to be able to use poorer quality source waters for drinking water production. Once considered as an expensive, ultimate solution for water supply, desalination is becoming affordable. The two most commonly used seawater desalination methods are Multi-stage Flash Distillation (MSF) and Seawater Reverse Osmosis (SWRO). SWRO is less energy demanding compared to MSF, which makes it economically attractive. However there is no backpulsing of the expensive and delicate reverse osmosis (RO) membranes with air or water, so they are susceptible to fouling, causing the loss of their performance. Therefore cleaning the feed water to the highest level possible by nanofiltration, before it reaches the RO membranes would highly increase the efficiency of the process. Nanofiltration (NF) as a feed pre-treatment step is a pressure driven membrane separation process that takes place on a selective layer formed by a semipermeable membrane with properties between RO and ultrafiltration. The objective of this project is the developement of highly efficient thin-film composite (TFC) membranes for SWRO pre-treatment processes based on low-fouling cyanobacterial extracellular polymeric substances (EPS). TFC membranes combine high flux and mechanical strenght, and they are expected to be the key components of any water purification technology in the future. Cyanobacterial EPS are complex heteropolysaccharides with putative antimicrobial and antiviral properties and a particular affinity to bind metal ions [1,2].Within this work, the unicellular N2-fixing marine cyanobacterium Cyanothece sp. CCY 0110 was chosen for RPS production, since it is among the most efficient released polysaccharide (RPS) producers and the polymer has been previously extensively characterised [3]. RPS was produced by growing Cyanothece CCY 0110 in 10L bioreactors, in conditions previously defined and the polymer was isolated following the standard methodology [3]. A polyvinyl alcohol (PVA) / cyanobacterial EPS blend nanofibrous membranes were fabricated by electrospinning using polyvinylidene fluoride (PVDF) as a basal membrane, in order to obtain thin-layer composite nanofiltration membranes. The production of the nanofibers using EPS and PVA as plasticizer in different ratios was produced in a NF-103 MECC Nanon electrospinning equipment with an applied electric field between 15 and 25 kV and a flow of 0,2 mL/h. Morphological, mechanical, chemical and thermal characterization of the electrospun fibers deposited on the basal membranes, were evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), dynamical and mechanical analysis (DMA), thermogravimetry (TGA) and differential scanning calorimetry (DSC). The AFM and SEM results show the presence of fibers with dimensions between 54 and 121 nm with low bead formation. In the EDS analysis presence of sulfur elements was observed confirming the inclusion of EPS in the nanofibers. The morphology and diameter of the nanofibers were mainly affected by the concentration of the blend solution and the weight ratio of the blend, respectively. The best PVA/EPS nanofibers were achieved in a ratio of 12 % PVA and 0.4 % EPS. The solution conductivity was ranging 1500 to 3500 μS/cm with a viscosity of about 100 to 500 cP. The DMA results confirmed the miscibility of PVA/EPS blends. The elastic modulus of the nanocomposite mats increased significantly as a consequence of the reinforcing effect of EPS. Thermal and mechanical analysis demonstrated that there were strong intermolecular hydrogen bonds between the molecules EPS-PVA in the blends. The heat-treated electrospun blended membranes showed better tensile mechanical properties when compared with PVA alone, and resisted more against disintegration. A lab-scale nanofiltration was performed in a bench stainless steel Sterlitech tangential flow stirred cell (200 mL) connected to an air pressure system that allow pressure driven filtration up to 10 BAR. Bactericidal activity and biofilm formation were tested using Escherichia coli and Sthaphylococcus aureus as pathogenic microorganisms

Furanchalcone–biphenyl hybrids: synthesis, in silico studies, antitrypanosomal and cytotoxic activities

The synthesis, antitrypanosomal, and cytotoxic activities of 17 furanchalcone derivatives are described herein. The structure of the synthesized products was elucidated by a combination of spectrometric analyses. The synthesized compounds were evaluated against Trypanosoma cruzi, which is the pathogenic species to humans. Cytotoxicity was evaluated against human U-937 macrophages. Eleven compounds were active against amastigotes of T. cruzi with EC50 values lower than 40 µM. Hybrids 7b–7d and 8a–8g showed better activity than benznidazole. Structure activity relationship (SAR) showed that the presence of electron withdrawing groups, such as nitro or fluorine, increased the activity and that the degree of oxygenation is essential for activity. In addition, molecular docking was used to identify a possible protein target for the designed compounds. A spearman correlation of 0.608 between the predicted scores and the experimental data profile the enzyme cruzipain as a potential candidate. Finally, in silico ADMET studies of the arylfuranchalcones showed that these novel compounds have suitable drug-like properties, making them potentially promising agents for antichagasic therapy

Paper-based laser-induced graphene for sustainable and flexible microsupercapacitor applications

Funding Information: Open access funding provided by FCT|FCCN (b-on). This work was financed by national funds from Fundação para a Ciência e a Tecnologia (FCT), I.P., in the scope of the projects LA/P/0037/2020, UIDP/50025/2020, and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication–i3N and by FEDER funds through the COMPETE 2020 Program and National Funds through Portuguese Foundation for Science and Technology under projects POCI-01–0145-FEDER-007688, UID/CTM/50025 and by ERC AdG grant from the project DIGISMART (ERC-AdG-2017, GA 787410). J.C. would like to acknowledge FCT/MCTES for his present research contract with reference CEECIND/00880/2018. R.C. acknowledges funding from i3N-FCT I.P. through the PhD Grant UI/BD/151295/2021. S. S. and T. P. also acknowledge the funding from National Foundation for Science and Technology, through the PhD Grants SFRH/BD/149751/2019 and 2020.08606.BD, respectively. Publisher Copyright: © 2022, The Author(s).Laser-induced graphene (LIG) is as a promising material for flexible microsupercapacitors (MSCs) due to its simple and cost-effective processing. However, LIG-MSC research and production has been centered on non-sustainable polymeric substrates, such as polyimide. In this work, it is presented a cost-effective, reproducible, and robust approach for the preparation of LIG structures via a one-step laser direct writing on chromatography paper. The developed strategy relies on soaking the paper in a 0.1 M sodium tetraborate solution (borax) prior to the laser processing. Borax acts as a fire-retardant agent, thus allowing the laser processing of sensitive substrates that other way would be easily destroyed under the high-energy beam. LIG on paper exhibiting low sheet resistance (30 Ω sq−1) and improved electrode/electrolyte interface was obtained by the proposed method. When used as microsupercapacitor electrodes, this laser-induced graphene resulted in specific capacitances of 4.6 mF cm−2 (0.015 mA cm−2). Furthermore, the devices exhibit excellent cycling stability (> 10,000 cycles at 0.5 mA cm−2) and good mechanical properties. By connecting the devices in series and parallel, it was also possible to control the voltage and energy delivered by the system. Thus, paper-based LIG-MSC can be used as energy storage devices for flexible, low-cost, and portable electronics. Additionally, due to their flexible design and architecture, they can be easily adapted to other circuits and applications with different power requirements. Graphical Abstract: [Figure not available: see fulltext.]publishersversionpublishe

A perspective on fundamental principles, applications, and challenges

Funding Information: This study was financed in part by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001. The authors would like to thank the financial support given by CNPq—National Council for Scientific and Technological Development (Grant Nos. 402287/2013–4, 304044/2019–9, and 442575/2019–0), SISNANO/MCTI, Financier of Studies and Projects (FINEP) and Brazilian Agricultural Research Corp. (Embrapa) AgroNano research network. The authors would like to acknowledge the European Commission under the Project NewFun (Grant No. ERC-StG-2014, GA 640598). This work was also supported by European Research Council (ERC) Advanced Grant DIGISMART (Grant No. ERC-AdG-2017, GA 787410) and the FEDER funds through the COMPETE 2020 Program and the National Funds through the FCT—Portuguese Foundation for Science and Technology under the Project No. POCI-01–0145-FEDER-007688, Reference UID/CTM/50025; Project CHIHC, Grant No. PTDC/NAN-MAT/32558/2017; and Project BEST, Grant Nos. ALT20–03-0247-FEDER-113469 and LISBOA-01–0247-FEDER-113469. J. C. acknowledges the Santander/NOVA 2021 Collaborative Research Award—Graphene Smart Bandages for Diabetic Foot Ulcer Monitoring, Reference GSBDFULM. P. C. acknowledges BI-84-Mestre-DIGISMART and CAPES/Embrapa (Grant No. 88882.157024/2017 01) for the scholarships received. S. S. and T. P. also acknowledge the funding from National Foundation for Science and Technology, through the Ph.D. Grant Nos. SFRH/BD/149751/2019 and 2020.08606.BD. Publisher Copyright: © 2022 Author(s).Since the discovery of laser-induced graphene (LIG), significant advances have been made to obtain green LIG (gLIG) from abundant, eco-friendly, natural, and organic renewable bio-based carbon sources. Recently, some sustainable and cost-effective electronic devices have been designed with gLIG, resulting in diverse solutions to the environmental impact caused by electronic waste (e-waste). However, there are still several challenges that must be addressed regarding the widespread market implementation of gLIG-based products, from synthesis to practical applications. In this review, we focus on sustainable precursor sources, their conversion mechanisms, physical and chemical properties and applications, along with the challenges related to its implementation, showing the future opportunities and perspectives related to this promising new material. Various systems based on gLIG for energy storage, electrocatalysis, water treatment, and sensors have been reported in the literature. Additionally, gLIG has been proposed for ink formulation or incorporation into polymer matrices, to further expand its use to non-carbon-based substrates or applications for which pristine LIG cannot be directly used. In this way, it is possible to apply gLIG on diverse substrates, aiming at emerging wearable and edible electronics. Thus, this review will bring an overview of gLIG developments, in accordance with the European Green Deal, the United Nations Sustainable Development Goals and the new era of internet-of-things, which demands cost-effective electronic components based on the principles of energy efficiency and sustainable production methods.publishersversionpublishe

Repeat Course Of Rabbit Antithymocyte Globulin As Salvage Following Initial Therapy With Rabbit Antithymocyte Globulin In Acquired Aplastic Anemia

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Catch Crop Residues Stimulate N2O Emissions During Spring, Without Affecting the Genetic Potential for Nitrite and N2O Reduction

Agricultural soils are a significant source of anthropogenic nitrous oxide (N2O) emissions, because of fertilizer application and decomposition of crop residues. We studied interactions between nitrogen (N) amendments and soil conditions in a 2-year field experiment with or without catch crop incorporation before seeding of spring barley, and with or without application of N in the form of digested liquid manure or mineral N fertilizer. Weather conditions, soil inorganic N dynamics, and N2O emissions were monitored during spring, and soil samples were analyzed for abundances of nitrite reduction (nirK and nirS) and N2O reduction genes (nosZ clade I and II), and structure of nitrite- and N2O-reducing communities. Fertilization significantly enhanced soil mineral N accumulation compared to treatments with catch crop residues as the only N source. Nitrous oxide emissions, in contrast, were stimulated in rotations with catch crop residue incorporation, probably as a result of concurrent net N mineralization, and O2 depletion associated with residue degradation in organic hotspots. Emissions of N2O from digested manure were low in both years, while emissions from mineral N fertilizer were nearly absent in the first year, but comparable to emissions from catch crop residues in the second year with higher precipitation and delayed plant N uptake. Higher gene abundances, as well as shifts in community structure, were also observed in the second year, which were significantly correlated to NO3- availability. Both the size and structure of the nitrite- and N2O-reducing communities correlated to the difference in N2O emissions between years, while there were no consistent effects of management as represented by catch crops or fertilization. It is concluded that N2O emissions were constrained by environmental, rather than the genetic potential for nitrite and N2O reduction

Mutational screening of the USH2A gene in Spanish USH patients reveals 23 novel pathogenic mutations

<p>Abstract</p> <p>Background</p> <p>Usher Syndrome type II (USH2) is an autosomal recessive disorder, characterized by moderate to severe hearing impairment and retinitis pigmentosa (RP). Among the three genes implicated, mutations in the <it>USH2A </it>gene account for 74-90% of the USH2 cases.</p> <p>Methods</p> <p>To identify the genetic cause of the disease and determine the frequency of <it>USH2A </it>mutations in a cohort of 88 unrelated USH Spanish patients, we carried out a mutation screening of the 72 coding exons of this gene by direct sequencing. Moreover, we performed functional minigene studies for those changes that were predicted to affect splicing.</p> <p>Results</p> <p>As a result, a total of 144 DNA sequence variants were identified. Based upon previous studies, allele frequencies, segregation analysis, bioinformatics' predictions and <it>in vitro </it>experiments, 37 variants (23 of them novel) were classified as pathogenic mutations.</p> <p>Conclusions</p> <p>This report provide a wide spectrum of <it>USH2A </it>mutations and clinical features, including atypical Usher syndrome phenotypes resembling Usher syndrome type I. Considering only the patients clearly diagnosed with Usher syndrome type II, and results obtained in this and previous studies, we can state that mutations in <it>USH2A </it>are responsible for 76.1% of USH2 disease in patients of Spanish origin.</p

De lazos familiares a redes sociales: nuevos aportes para la discusión de interacciones entre poblaciones de la Puna y las tierras bajas orientales.

El objetivo de este trabajo es presentar un conjunto de evidencias vinculadas con un contexto funerario (1280 ± 60 años AP) procedente del sitio Punta de la Peña 13, Antofagasta de la Sierra, Puna meridional argentina. Con este fin llevamos a cabo un abordaje multidisciplinario que incluyó diversas líneas de análisis: composicionales de cuentas minerales, arqueobotánicos y tecnomorfológicos de artefactos cerámicos y textiles. Los resultados obtenidos permitieron plantear el origen no local para el conjunto mortuorio como rasgo complejo, que a su vez relacionamos con las Tierras Bajas orientales, proponiendo la existencia de interacciones con las poblaciones de la Puna. Estos estudios fueron complementados con información arqueológica y antropológica acerca del conjunto de prácticas vinculadas con las particularidades del contexto. En este sentido, si bien ya habían sido registrados elementos no locales en contextos funerarios del área, inferimos que contenedor y contenido funerario fueron trasladados como una totalidad desde una región alejada, hecho que representa una propuesta inédita y con implicancias relevantes para la puna meridional.Fil: Lopez Campeny, Sara Maria Luisa. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Romano, Andres Sebastian. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; ArgentinaFil: Rodríguez, M .Fernanda. Secretaría de Cultura de la Nación. Dirección Nacional de Cultura y Museos. Instituto Nacional de Antropología y Pensamiento Latinoamericano; ArgentinaFil: Corbalán, Mariano H.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Martel, Alvaro Rodrigo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Estudios Sociales. Universidad Nacional de Tucumán. Instituto Superior de Estudios Sociales; Argentin

Three red suns in the sky: A transiting, terrestrial planet in a triple M-dwarf system at 6.9 pc

We present the discovery from Transiting Exoplanet Survey Satellite (TESS) data of LTT 1445Ab. At a distance of 6.9 pc, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use MEarth data and results from the Science Processing Operations Center data validation report to determine that the planet transits the primary star in the system. The planet has a radius of ${1.38}_{-0.12}^{+0.13}$ ${R}_{\oplus }$, an orbital period of ${5.35882}_{-0.00031}^{+0.00030}$ days, and an equilibrium temperature of ${433}_{-27}^{+28}$ K. With radial velocities from the High Accuracy Radial Velocity Planet Searcher, we place a 3σ upper mass limit of 8.4 ${M}_{\oplus }$ on the planet. LTT 1445Ab provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. We also present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicate a moderate amount of variability, in agreement with that observed in the TESS light-curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system hints that the entire system may be co-planar, implying that the system may have formed from the early fragmentation of an individual protostellar core.Accepted manuscrip